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The GUI User Manual for the CTUns 6.0 etwork Simulator and

1. IEEE 802 16 e PMP mode Mobile Station The following figure illustrates an example of the IEEE 802 16 e PMP network which comprises three PMP BS nodes and one PMP MS node The three BS nodes manage 156 three different subnets respectively As such they are inter connected with routers In this simulation case the MS node periodically transmits data packets to a host which is connected to this 802 16 e network via a fixed line and moves towards the right at a constant speed erwin tayinini trara aroma phreen wsagoyvuyvuus Seeu es he IB rr JELLGAALGA EB ALA Faces va IBeM Str RRIT ARAB AZA DERP T amp l VA fDi Oe Gj il Setting IEEE 802 16 e PMP Networks In the following we show how to use the GUI program to generate an IEEE 802 16 e PMP network simulation case Insert PMP Nodes To deploy an IEEE 802 16 e PMP network one can either insert IEEE 802 16 e PMP nodes one at a time or insert a number of nodes in one single step by using the Insert 802 16 e PMP Mode Nodes command The path for launching this command is Menu gt N_ Tools gt 802 16 d Network gt 802 16 e PMP Mode Nodes gt Insert 802 16 e PMP Mode Nodes Asd i TEET ERRET Saee sw I0 ij wa Bal hie La ALLTAL cium e a a iu CEE E ARARSA S OER P 157 The following dialog box shows the layout of the Insert 02 16 e PMP Mode Nodes command As
2. Cancel p Propagation Delay Link Failure The PHY module in the node editor To enable the down time setting of an interface a user needs to open the node s node editor double click that interface s physical layer module PHY WPHY AWPHY or OPT_PHY and make sure that the Link Failure option is checked If that option is not properly checked an interface s down time periods that come from either a node or a link will not take effect during simulation To see the current down time setting for the interface the user can click the See Down Time Setting button A user can also set the down time periods of a link By double clicking a link a link property dialog box will show up In the dialog box a user can set the link s bandwidth signal propagation delay bit error rate BER and down time periods for each direction of the link If the link is an optical link with multiple channels the same dialog box can be used to set the property of each channel The following figure shows the property dialog box of an optical link The C T A C button stands for Copy To All Channels of this selected link This function is enabled only when the user is specifying the property of a channel of an optical link When double clicking an optical link the GUI will first ask the user which channel of the link he she wants to configure Clicking t
3. V Insert 802 16 j Transparent Mode Nodes 00 Q Insert 802 16 j nodes at random positions Insert 802 16 j nodes array At random positions eee xo Yio Create nodes Protocol stack Node editor m Dimension Row fi Column ih r Node spacing 200 meter C e E 802 16 j Fixed RS Node m Protocol stack Node editor 802 16 j MS Node Cancel Specify and Manage IEEE 802 16 j Transparent Mode Network Subnets To automatically generate the IP addresses for the wireless nodes in an IEEE 802 16 j transparent mode network the subnet must be explicitly specified using the form subnet tool on the tool bar The usage of this tool is described here One first clicks the form subnet icon on the tool bar and then chooses the nodes that he she wants to group together to form a subnet by left clicking their icons in the working area To end the grouping action one can right click the background of the working area of the GUI program Doing so will pop up a dialog box that shows the IDs of the nodes that are chosen to form the subnet One can also manage the created subnets via the Manage 802 16 j Subnet command which is located at Menu gt N_Tools gt 802 16 j Network gt 802 16 j Subnets If one wants to delete a created subnet he she can simply click the Delete Subnet command which is shown in the dialog box below Set
4. 9 98096415 9 87869532 9 78395339 9 69641676 9 61580050 9 54185223 9 47434852 9 41309197 9 35790869 9 30864619 9 26517156 9 22737002 9 19514358 9 16841007 9 14710225 9 13116708 9 12056528 9 11527085 allows users to conduct simulation using an arbitrary antenna gain pattern To accomplish this one should first turn on the Use user defined antenna gain pattern option and then specify the path of his her own antenna gain pattern file in the circled antenna pattern file field A O v Use user defined antenna gain pattern file browser aT J antenna can be shown by clicking on the above two buttons respectively The antenna gain is expressed in dBi and each number represents the gain in a particular degree The first number is the gain along the pointing direction Then each successive number represents the gain in the next degree clockwise In total 360 gain numbers are calculated and listed When the 360 degree option omnidirectional is chosen the antenna gains in all 360 degrees use the same value of 2 dBi Antenna pattern file The format of an antenna gain pattern file agp file is simple Each line represents a gain value entry which is composed of two fields separated by a comma The former field denotes the degree of the antenna relative to its pointing direction while the latter is the gain value of the antenna in dBi The following figure s
5. Edit the car profile mapping file button This function may be desired when the user wants to explicitly specify which car should use which car profile during simulation The following figure shows the dialog box popped up after clicking the button In this box one can first click the desired car to choose it and then click the Change Profile button to change the profile assigned to the chosen car 141 7 EZ 25 Sl as eB Sl a The following figure shows the popped up dialog box in which the user can change the profile assigned to the chosen ITS car Agent Programs When a crossroad is deployed a signal agent will be automatically run up when a simulation starts The signal agent is responsible for changing the states of the traffic light Similarly when an ITS car is deployed a car agent will automatically be run up when a simulation starts The car agent is responsible for driving the car based on its assigned car profile Like a user level real life application program all of these agent programs are user level programs written in C C and the command strings for launching these programs during simulation should be typed into the Application tab of each of these nodes However considering that hundreds of ITS cars may need to be automatically deployed on a road network In such a case asking the user to open the dialog box of every ITS car to manually
6. External Router ID 140 C Use a real router to connect multiple emulation n 192 168 1 1 192 168 1 2 192 168 1 3 192 168 1 1 192 168 1 2 192 168 1 3 Node editor Cancel After finishing configuring the virtual router one can switch the GUI into the Run Simulation mode and start running the distributed emulation Example 3 In example 3 we demonstrate a distributed emulation case that uses two virtual routers to partition the network topology into three parts Note that it is important to properly configure the physical links among all emulation machines before the emulation is started As shown in the following figure the example topology contains two virtual routers Each virtual router connects with two subnets and the 1 0 2 0 24 subnet is connected to both virtual routers In this example case the host 1 0 1 1 wants to establish a TCP connection with the host 1 0 3 1 and the host 1 0 3 1 wants to establish a TCP connection with the host 1 0 2 1 In this example case we demonstrate the steps to configure the simulation case using two typical physical network configurations In the first configuration the two virtual routers are mapped to two real routers in the second config uration the three emulation machines are connected via two switches Use two real routers to connect emulation machines 70 TCP Connection As shown below the IP address of the emulation machine for emulating the
7. Node editor Cancel The router s dialog box In the second step a user can use the node editor to specify the protocol module parameters used inside a network node To enter the node editor a user first double clicks the node s icon to pop up its dialog box Then the user double clicks the node editor button in the dialog box The following figure shows the popped node editor and the protocol modules used inside the router One important task in the Edit Property mode is to specify which application programs traffic generators should run on which nodes during simulation to generate network traffic Application programs can run on hosts routers mobile nodes including both the ad hoc and infra structure modes GPRS phones IEEE 802 16 d WiMAX BS and SS IEEE 802 16 e mobile WiMAX BS and MS IEEE 802 160 relay WiMAX BS RS and MS DVB RCST ITS MAC80211 WPHY ao211P VAP V ARP DVB_S2_FEEDER D MAC8021 MAC8021 MAC8021 bF r m ARP ARP ARP ARP FIFO FIFO FIFO FIFO S E E MAC8023 MAC8023 MAC8023 1o Sn aoe TCPDUMP TCPDUMP TCPDUMP TTT ns _ Select Mode A gt T A N OK k x Undo Redraw T A The popped up node editor for the router node cars multi interface nodes 802 11 p OBU and RSU etc Actually as long as a node has a layer 3 interface which should have an IP address assigned to it any application program can run on i
8. mode can a user draw a new network topology or change an existing simulation case s topology When a user switches the mode to the next mode Edit Property the simulation case s network topology can no longer be changed Instead only devices properties attributes can be changed at this time The GUI program enforces this rule because when the 99 mode is switched to the Edit Property mode for the user s convenience the GUI program will automatically generate many settings e g a layer 3 interface s IP and MAC addresses Since the correctness of these settings depends on the current network topology if the network topology gets changed these settings may become incorrect If after editing some devices properties the user would like to change the network topology he she will need to explicitly switch the mode back to the Draw Topology mode However when the mode is switched from the Draw Topology mode back to the Edit Property mode again many settings that were automatically generated by the GUI program will be re generated automatically by the GUI program to ensure their correctness For example the IP and MAC addresses automatically assigned to a layer 3 network interface may have been changed The user thus better re checks the settings for application programs traffic generator that he she specified when he she was in the Edit Property mode This is because th
9. Add button will pop up the dialog box for adding deleting a service information entry which is shown in the following figure As one sees this dialog box contains three fields The first field is the Time to Register Service field which denotes when this OBU intends to subscribe to this service The second field is the Action field which denotes the action that this OBU intends to do on this service on the given time Two actions are now supported Add a service to the subscription table and Delete a service from the subscription table The last field is the Provider Service Identifier PSI field which denotes the numerical identifier of the chosen service WV IEEE 80211 p OBU MobileID 4 Name EE 802 11 p Provider Setting IEEE 802 11 p User Setting User Service Information Tab Delete C P AN S T Node editor V Service Information Record Time to Register Servi Action Provider Service Identifier Cancel The following figure shows an example user setting for an 802 11 p OBU node In this example the OBU subscribes to three services with IDs 1 2 and 3 at the first second of the simulated time If the OBU receives WSAs of the services 1 2 and 3 after the 1st second of the simulated time its Wave Management Entity WME module will trigger its internal procedure to attach to the WBSSs of these three services for receiving their broadcast messages
10. Grouping Return link capacity Return link frequency Forward link arrangement Range of superframe D0 4 from 1 to 255 DVB RCS Network Control Center ID 21 There are 5 channels over the return link Central frequency of the whole return uplink channel band 31 GHz Central frequency of the whole return downlink channel band 29 GHz Symbol rate per channel 9935000 symbol sec Roll off factor 0 400 Each channel s bandwidth is 13909000 059 Hz Number of ATM cell s per slot 2 Ir Burst start offstet Preamble ATM Cells Burst start offset Preamble length 16 symbol s Burst start offset guard time 2 i 1 symbolis The structure of a slot Number of Data slot s per frame 95 from 1 to 2048 Number of Request slot s per frame 5 Number of frame s per superframe 10 from 1to 32 Coding amp Modulation Reed solomon Error Correction 8 amp Convolution code 1 2 amp QPSK 1 2 Re The period of a slot is 0 100000 ms The period of a frame is 10 00000 ms The period of a superframe is 100 00000 ms Node editor Cancel The resulting maximum channel transmission capacity can be viewed on the tab of Return link capacity The following figure shows the dialog box of this tab The usage of this tab will be described later The formulas for calculating the periods of a timeslot a frame and a superfra
11. are delivered from one end to the other end immediately without simulating the delay and bandwidth of the under lying physical links Effectively we can view that the simulated link delay is O and the simulated link bandwidth is infinite for the link between SGSN and GGSN Although this settings may be different from the settings in the real world generally it is not a concern This is because under this situation a more bottlenecked link 36 12 Kbps exists between MS and BS Therefore using an infinite bandwidth link to simulate the link between SGSN and GGSN does not affect GPRS simulation results Form Wireless Subnet The icons of GPRS related nodes are shown below GGSN T SGSN GPRS base station ili GPRS phone i and GPRS pseudo switch The following figure shows an example GPRS simulation case In NCTUns the GPRS backbone network forms a subnet regardless how many SGSNs base stations and single phones are inside it Using the following figure as an example the devices on the left side of the GGSN form a single subnet This is because in NCTUns GPRS switches SGSNs and base stations are all treated as layer 2 devices while GGSNs are treated as layer 3 routers After inserting GPRS related nodes a user must use the Form wireless subnet tool to select all GPRS phones and all GPRS base stations to group them together to form a wireless subnet Specifying this relationship enables the GUI
12. these exported simulation files will be stored in a directory named test sim Among these exported files the test tcl file stores the configuration of each node s protocol stack and the network topology information This file is very important and should always go with the test tpl and test xtpl files Therefore if a user wants to move or copy a simulation case from one place to another place in a file system he she must move or copy the tpl and xtpl files and their associated sim directory at the same time Otherwise the moved or copied simulation case cannot be successfully reloaded For this particular example he she must move test tpl test xtpl and test sim at the same time In addition to the sim directory a directory named mainFileName results is also created This directory will store the generated simulation results when they are trans ferred back to the GUI program after the simulation is finished It is important to note that before a user runs a simulation case he she can still switch the mode back to the Edit Topology or even the Draw Topology mode to change any setting of the simulation case However when the mode is switched back to the Run Simulation mode all simulation files will be re exported to reflect the most recent settings Before a user runs a simulation he she must make sure that the dispatcher and coordinator are already running Suppose that t
13. 76800 bps Remaining REDC Peak Rate 384000 bps Queue Length ATM cells CRA Rate 1843200 bps RBDC Peak Rate bps OE Cancel If the transmission priority is set to VR_RT one has to set the queue length the CRA rate and the RBDC Peak Rate oF Service Detail amp 3 Remaining CRA Capacity 76800 bps Remaining RBDC Peak Rate 384000 bps Queue Length ATM cells CRA Rate 1843200 bps RBDC Peak Rate bgs OK Cancel If the transmission priority is set to VR_JT one has to set the queue length and RBDC peak rate Service Detail Qs oe Transmission Priority Remaining CRA Capacity 76800 bps Remaining RBOC Peak Rate 384000 bps Queue Length 83027 ATM cells CRA Rate 18435200 bps RBDC Peak Rate bgs Or Cancel If the transmission priority is set to JT one only needs to set the queue length Service Detail w w amp i Transmission Priorits Remaining CRA Capacity Remaining RBOC Peak Rate Queue Length ATM cells CRA Rate bps REDC Peak Rate bps OK Cancel Protocol Stack In the following the protocol stack of each RVB RCS node will be shown In a protocol stack some protocol modules are used only for the forward link while some are used only for the return link In such a special case their attribute will be clearly shown next to the module icon box The protoc
14. AP ARP DVB_S2 FEEDER D VB_S2 RCST FWD lt l lt lt mean Doone amenoasi mmea gt Return link Forward link Antenna and Rain Fade Configuration Regarding the antenna and rain fade configurations one has to set the related parameters for the forward link and the return link The following figure shows where one can set parameters for the forward link These places include the sending point at the Feeder node the receiving point at the Satellite node the sending point at the Satellite node and the receiving point at a RCST A XA en VSat w ageuvuuvvusg S eeuwusv Ip so SSBB rro syv LL4ALALS ACM AALSBALSN FSALPeORD Beebeerer ARMA RARAR DER P wa nk R ts To configure the sending point at the Feeder node one can pop up the node editor of the Feeder node first After double clicking the DVB_S2_ FEEDER module box one will see a popped up dialog box shown below V Module Edit aD Feeder Parameters Setting Interface Number 1 Rainfade OK Default d Buffer Size 20000000 Bytes IET dBi Cancel Symbol Rate 8 Msymbol s z User Defined Tx Power 10 w j Antenna Angle 89 degree Ground Station Antenna Length 13 rm a NRN Polarization 0 degree Ground Station Antenna Efficiency 0 68 0 for horizontal polarization 45 for circular polarization x His Failure 90 for vertical polarization See Down Time Setting Ra
15. Application Down time Interface Mobile IP Single gt Enable Mobile IP Home Agent IP Address My own IP Address aM Node editor OK Form Wireless Subnet After the mobile host is inserted a user must use the Form wireless subnet tool to select it and the home IEEE 802 11 b access point to group them together to form a wireless subnet Specifying this relationship enables the GUI program to automatically assign IP and MAC addresses to 75 the mobile host saving much time and effort of the user The subnet ID of the home subnet is automatically assigned by the GUI program and can be known by moving the mouse cursor over the blue interface box on the bottom side of the right most router The formed wireless subnets can be viewed and managed by executing the Menu gt N_Tools gt 802 11 b Wireless Network gt Manage 802 11 b Infra structure Mode Subnets command The following figure shows the dialog box of this command qe aip inae er j TETU ICL ee re EE EE M e L a M a E 2S a T sO E R P Eie Bai g Tn Tee 7 he ot BORER r y iat i CELLULES ILLL jrid Er es EI p 5 mo m OD Oe Fasa mon nes saa B rin ssn oon oe fel a a P E Hfi 2s i beme y Router Routers are the places where the home agent and the foreign agent reside In NCTUns the functionality of a home agent and that of a foreign agent are combined toge
16. W IEEE BOPTI p OB IEEE 8021 p Provider Setting IEEE 80211 p User Setting Application 4 gt User Service Information Table ERR Action Provider Ser Ti te to Register Service Add l Add 2 dd The functions of the Application Path Down Time Mobile IP tabs of an 802 11 p OBU are the same as those of an 802 11 b infrastructure mode mobile node To save space we do not explain them here One can refer to previous chapters for their usages Note that it is not recommended to specify the moving path of an ITS car using the functions on the Path tab because if the ITS car specifies a Car Agent program to dynamically control its moving path these two moving control mecha nisms will interfere with each other resulting in unexpected simulation results For this reason these two moving control mechanisms should not be used simultaneously 145 Setting for WSM Transmission The following figure shows the protocol stack of an IEEE 802 11 p 1609 network As one sees the IEEE 1609 3 specification defines the Wave Short Message Protocol WSMP which is a layer 3 and layer 4 protocol to regulate transmission and reception of WSMs Due to the unique architecture of NCTUns the most direct way to support WSMP would be to implement it in the Linux kernel However this way NCTUns will need to modify the current Linux kernel network subsystem and socket APIs to a great extent which greatly increases the complex
17. WiVeC 2008 The Concept of the WAVE Mode The WAVE mode defines the operations for the IEEE 802 11 based device in environments where the physical layer properties are rapidly changing and where very short duration communications exchanges are required e g a 138 vehicular network The purpose of this standard is to provide the minimum set of specifications required to ensure interop erability between wireless devices attempting to commu nicate in potentially rapidly changing communications environments and in situations where message delivery must be completed in time frames much shorter than the minimum in 802 11 based infrastructure or ad hoc networks 3 The 802 11 p specification supports transmission of Internet Protocol IP packets and WAVE Short Messages WSMs Frequency SCH 3 SCH 2 SCH 1 CCH 50 100 150 200 250 Time ms HNN Transmission Cycle Transmission Cycle Transmission Cycle Lo Control Frame As shown in the above figure the used frequency spectrum in an 802 11 p network is divided into one control channel CCH and several service channels SCHs The CCH is dedicated for nodes to exchange network control messages Service Frame while SCHs are used by nodes to exchange their data packets and WSMs The link bandwidth of these channels is further divided into transmission cycles on the time axis each comprising a control frame and a service f
18. and one or multiple RCST nodes After left clicking all of the required nodes one can right click the mouse to complete the subnet formation process The following figure shows an example operation of the Form Subnet operation VM Ae oe 4 Ipap n ajuat e ganus ia oo sem wre su LLALLA CSR LBALS Pe ae BREESE BEL AREER eS OERP E E XS i a J A d gt dka S 0 000 00 on om AQ er ilar A Form Subnet example in which one Satellite node one TG node one Feeder node one NCC node one SP node and two RCST nodes are selected to form a DVB RCS subnet After right clicking the mouse to end the subnet formation process one can see a popped up dialog box showing the node ID of every selected node One can click the OK button to confirm this formation or click Cancel button to cancel this formation h Ta gi Q w Nodes Chosen for This Subnet ID of chosen nodes After the DVB RCS subnet formation has been completed one can check the formation results and delete any formed subnet by using the Menu gt N_Tools gt DVB RCST Satellite Network gt Manage DVB RCST Subnets command The following figure shows where this command is located 126 A A E 7 A p S ji hs X x a H ao Fi AB i AET y GA GA a ioe In the popped up subnet management dialog box one can see the node IDs of the nodes belonging to a subnet One can choose an existing sub
19. attribute specification 2 channel model specification 3 connectivity calculation and display and finally 4 antenna gain pattern and directivity specification By coordinating the functions of these components this tool can greatly save one s time and efforts required to specify a network case with sophisticated physical layer setting In this chapter we explain the usage of this tool in detail hysical layers and chanel models play important Launching This Tool aN To start this tool one should first click the 2 icon on the icon list panel which is at the top the GUI program and then click the icon of a wireless node that he she intends to configure After this is done the following dialog box will pop up Y Specaty physical loyer and channel sodel parvecters Fropegation Channa Model Frequency Metz e Thecretca Chane Mode foangver 0 0 Poth Logs Moda F sng Mode Ricesrk broka Cire Moud Tintori im Systerrioss Node Connectivity Display TranePower open Use the traneritting code perspective Use the recaro fode perspective AverageBuidingteignt m StreetWiith mm Averageiutderixstance 11 PathLossioponernt Antenna Gan Pattern and Deectiity StamderdDevietion Ceselnitstance m T1 Before going into the detailed setting we first explain the two modes provided by this tool to show node connectivity Using the first mode one can observe the radio connectivity of nodes from the perspectiv
20. downlink and uplink traffic for a GPRS user The default values are 3 and 1 for the downlink and uplink traffic respec tively To let all other base stations use the same time slot numbers the user can click the C T A B S button to copy the settings to all base stations Down time Frequency channel Channel slot Neight Downlink time slot number Uplink time slot number Node editor Cancel In the Neighborhood Radius tab of the base station dialog box a user can specify the radius of the neighborhood circle centered at this base station Every base station within this circle is considered to be a neighboring base station of this base station When a GPRS phone is associated with this base station this base station will notify it of the existence of these neighboring base stations The GPRS phone then uses its idle time slots to monitor the signal strength of these neighboring base stations This design will facilitate roaming and handoff between neighboring base stations The default value is 100 meters A user can change this value to suit his her needs w Base Station requency channel Channel slot Neighborhood radius BS ID Neighborhood radius meter 100 IMIS Parameter Species Ine raqgius of Ine neighborhood circle centered at this BS Every BS that is within this circle is considered to be a neighboring BS of this BS When a phone is associated with this BS it can use its idle time slots to m
21. form subnet button which is on the tool bar The procedures to specify and manage IEEE 802 160 non transparent mode subnets are the same as those to NETUS 6 0 version 4 L20009 File Edit G Tos Tools G Setting N Setling Simulation View Help gt A ow 9 BiZa Wireless Network a tyu Sewers ae w r 802 19 Wireless Network LALLY SHEEP iO eeeeese AAAA 80211 Wireless Network BOE p Vitineless Network BO 11 gt Viineless Mesh Network GPRS Network Optical Network OVE RCST Satediiie Metwork BL 1 a Network HI 15 e Nebwork E Transpareni Pico ITS Nebhwck DoS Diltsery Network Hotercgenegus Network Non iranspareni Moge BAIG Subneis ANAA AM EEE UA BN 1 000 000 090 oco specify and manage 802 16 j transparent mode subnets Reader can refer to the previous section Specify and Manage IEEE 802 16 j Transparent Mode Network Subnets for detailed information Set QoS Provision For Non transparent Mobile Stations The IEEE 802 160 network is QoS capable However the current IEEE 802 160 network implementation in NCTUns only supports the best effort service Therefore the only QoS parameter required for each NI MS node s QoS provision is the maximum uplink sustained rate in Kbps As a tule of thumb the sum of the uplink bandwidth allocated to each NT MS should not exceed the maximum bandwidth provided by the NT MR BS of the network For this reason one
22. it can act as router to connect the IEEE 802 16 d PMP network with another network As for a PMP host SS node this node type is used to represent a terminal device equipped with an IEEE 802 16 d PMP mode radio Such a node cannot act as a router to connect to another fixed network The following figure shows an example of IEEE 802 16 d PMP networks In this network there are one PMP BS node one PMP gateway SS node and a number of PMP host SS nodes The PMP BS node connects to the Internet at the top left via a fixed link while the PMP gateway SS node connects to a subnet at the bottom right via a fixed link Through the routing functions of the PMP BS and gateway SS nodes the hosts on the Internet in the PMP network and in the bottom right subnet can communicate with each other eo oO XA eos tet angoj yvu Pewee ae s BOER rre wb LLALLA TS ALS ALS PSR eh Beebe eweSete BE ARBRE A DOERP 3 i i 3 hs a_i is S e amp he ro 1 on n AQ ir ilar Setting IEEE 802 16 d PMP Networks In the following we show how to use the GUI program to generate an IEEE 802 16 d PMP network simulation case Insert PMP Nodes To deploy an IEEE 802 16 d PMP network one can either insert IEEE 802 16 d PMP nodes one at a time or insert a number of nodes in one single step by the Insert 802 16 d PMP Mode Nodes command The location of this command is Menu gt N_Tools gt 802 16 d Network gt 802 16 d PMP Mod
23. root Otherwise command console function cannot work correct OK Cancel This dialog box asks a user to provide the IP address and port number used by the dispatcher The GUI user s login account and password for using the remote can be local simulation server should also be provided here It is VERY important that the account name of the GUI user used on the local GUI machine and that used on the remote can be local simulation server should be exactly the same Otherwise the network simulator cannot work correctly For the single machine mode the user name specified here MUST be the same user account name by which the user logs into this local machine Otherwise the simulation cannot run correctly For security concerns the root account is not allowed and thus is blocked here by the GUI If the user is using the single machine mode the IP address entered here can be 127 0 0 1 the IP address of the loopback interface loO The port number entered here must be the same as the CLIENT_PORT specified in the dispatcher cfg Simulation The command for setting the various global parameters of the current simulation case is located in Menu gt G_ Setting gt Simulation Under the Simulation tab the total simulation time in virtual time and the maximum of X Y Z coordinates can be specified Currently the maximum time that can be simulated is 4 200 seconds in virtual time The user can select whether the ptr
24. shell is csh or tesh Similarly if the user uses bash he she can use the command source usr local nctuns etc nctuns bash to set these environment variables 2 Start up the dispatcher Now a user can run up the dispatcher which is located in usr local nctuns bin Note that the user must be the root user to run dispatcher correctly The default port number used by the dispatcher to receive messages sent from the coordinator program s is 9 810 It is 9 800 for the dispatcher to receive messages sent from the GUI program s These default settings can be found and changed in the dispatcher cfg file which is located in usr local nctuns etc 3 Start up the coordinator Now the user can run up the coordinator which is located in usr local nctuns bin Note that the user must be the root user to run coordinator correctly Since the coordinator needs to register itself with the dispatcher we must let the coordinator know the port used by the dispatcher to receive the registration messages It is 9 810 in the above example This port information is specified and can be changed in the coordinator cfg file located in usr local nctuns etc The second important information that the coordinator must know is the IP address used by the dispatcher If the user is using the single machine mode since the dispatcher and the coordinator are run on the same machine the IP address can be specified as 127 0 0 1 which is the default
25. transparent mode network simulation case Insert IEEE 802 16 j Nodes To deploy an IEEE 802 16 j transparent mode network one can either insert IEEE 802 160 transparent mode nodes one by one or deploy a number of nodes in batch by using the automatic deployment tool File Edit G Tools N Tools G Setting N Setting Simulation View Help t X v 802 11 a Wireless Network UQRuUus Hgo wegl Hel Zila YY i FL 802 11 b Wireless Network LALLA Sea YS OO BOSCBEBE 1E A A A 802 11 e Wireless Network 802 11 p Wireless Network 802 11 b Wireless Mesh Network GPRS Network Optical Network DVB RCST Satellite Network 802 16 d Network 802 16 e Network 802 16 j Network ITS Network QoS Diffserv Network Heterogeneous Network i Pe me w x a Transparent Mode M Insert 802 16 Transparent Mode Nodes Non transparent Mode 802 16 j Subnets 161 The following figure shows the layout of the Insert 02 16 j Transparent Mode Nodes tool whose path is Menu gt N_Tools gt 802 16 j Network gt Transparent Mode gt Insert 802 16 j Transparent Mode Nodes By using this tool one deploys 802 16 j transparent mode nodes at random locations or in a grid manner As one sees one can also specify 1 the type and the number of nodes to be deployed and 2 the protocol stack setting of the inserted nodes by clicking the Node Editor button
26. 07103380 5 60292903 5 10775455 4 58536278 4 03561454 3 45838540 2 85357323 2 22110704 1 56095682 0 873 14373 0 15774961 0 58507627 1 35511688 2 15209902 Degree Gain dBi 14 89342343 17 25871164 22 10439603 52 10439603 47 25871164 44 89342343 43 21711414 41 84813303 100 260 40 64349440 134 226 26 84056753 135 225 26 54161460 102 258 39 53687808 104 256 38 49422510 106 254 37 49722645 108 252 36 53594808 110 250 35 60511737 112 248 34 70210113 114 246 33 82575085 116 244 32 97572664 118 242 32 15209902 120 240 31 35511688 122 238 30 58507627 124 236 29 84225039 126 234 29 12685627 128 232 28 43904318 130 230 27 77889296 132 228 27 14642677 83 Degree Gain dBi Degree Gain dBi Degree Gain dBi 102 258 15 93582024 103 257 158 202 21 53599274 159 201 21 39793992 40 320 4 72793032 160 200 21 26638954 161 199 21 14132965 42 318 4 59612524 162 198 21 02274894 163 197 20 91063674 44 316 4 45473156 164 196 20 80498302 165 195 20 70577837 46 314 4 30310339 166 194 20 61301404 167 193 20 52668186 48 312 4 14049961 168 192 20 44677429 169 191 20 37328439 50 310 3 96606562 170 190 20 30620582 171 189 20 24553282 52 308 3 7788 1044 172 188 20 19126019 173 187 20 14338333 54 306 3 57757151 174 186 20 10189818 175 185 20 06680125 56 304 3 36100717 176 184 20 03808958 177 183 20 01576076 58 302 3 12748773 178 182 19 99981294 179 181 19
27. 3 dB beamwidths Ea ft tosh M ttot G Betting Te Tea Yer Bee BArc E4 eek e BPRS Lees i oe E EEN TTR SR LLLE LSE FBR SPLS BERR ASP Bi ASRS Roe DERP by omnidirectional antenna 120 degree directional antenna 60 degree directional antenna s00 DAA A 4D Ul m p Sm 1R La af When an omni directional antenna is chosen the antenna gains in all 360 degrees use the same value of 1 while when a sectored directional antenna is used its gains over different degrees can vary greatly NCTUns provides two example gain patterns for a 60 degree 3 dB beamwidth directional antenna and a 120 degree 3 dB beamwidth directional antenna respectively To show the detailed antenna gain value at each degree one can click the button 60 degree antenna pattern and 120 degree antenna pattern in the dialog box For users convenience we list the detailed gain values of these two gain patterns in all 360 degrees in the following 1 In these two gain patterns the antennas are assumed to point in the zero degree direction in which they generate the maximum gain values The Gain Pattern of the 60 degree Directional Antenna Provided by NCTUns Degree Gain dBi 10 00975522 9 98423924 9 93319875 6 354 9 85661667 8 352 9 75446718 9 8087398 1 9 351 Degree Gain dBi 9 62671561 9 47331814 9 29422163 9 08936326 8 85867035 8 60206008 8 31943940 8 01070498 7 67574336 7 31443 136 6 9266368 1 6 51221970 6
28. 6 Masaharu Hata Empirical Formula for Propagation Loss in Land Mobile Radio Services IEEE Transactions on Vehicular Technology Vol29 No 3 pp 317 325 August 1980 7 V S Abhayawardhana I J Wassell D Crosby M P Sellars and M G Brown Comparison of Empirical Propa gation Path Loss Models for Fixed Wireless Access Systems In Proc of the IEEE Vehicular Technology Conference VTC 05 Vol 1 May 30 Jun 1 2005 pp 73 77 Stockholm Sweden 8 V Erceg et al An empirically based path loss model for wireless channels in suburban environments IEEE JSAC vol 17 no 7 July 1999 pp 1205 1211 9 K Konstantinou A Measurement Based Model for Mobile to Mobile UMTS Links the IEEE 65th Vehicular Technology Conference 2007 VTC2007 Spring April 22 25 2007 pp 529 533 Dublin Ireland 10 D B Green M S Obaidat An Accurate Line of Sight Propagation Performance Model for Ad Hoc 802 11 Wireless LAN WLAN Devices Proceedings of IEEE ICC 2002 New York April 2002 11 Dongsoo Har HowardH Xia Henry L Bertoni Path Loss Prediction Model for Microcells IEEE Transactions on Vehicular Technology Vol 48 No 5 September 1999 12 H Xi A Simplified Analytical Model for predicting path loss in urban and suburban environments IEEE trans actions on vehicular technology vol 46 pp 1040 1046 1997 13 Lim J Shin Y amp Yook J Experimanetal perfor
29. 8000 8 audio Destination IP address es 0 PCMU 8000 8 audio Destination IP address es IP address us IP address Media type audio x i Media type 1 0 1 i add Destination port number UL Destination port number l Delete Payload type Payload type Encoding name Encoding name PCM Sampling rate HZ Sampling rate HZ 8000 Bits per sample Bits per sample 8 Audio packet time ms Audio packet time ms 20 Video frame rate F sec Video frame rate F sec Please reference RFC 3551 for explanations ins Paice Please reference RFC 3551 for explanations sae eel of these parameters of these parameters annaa Hostl s SDP dialog box Host2 s SDP dialog box 93 h Ta RTF Application Start Time End Time Application Name Local IP address Local port number Canonical name CNAME must be i a FA 0 000000 sec 250 000000 tsec ttprecvonly hi 1 0 13 5004 unique c nctu You need to input the SDP file name for the RTP application ample1_Node3 sdp Browse to select one if it exists Otherwise the required SOP file can be easily generated here Edit and save SOP information to a SOF file O based on a packet trace file Input trace file name Select this option if you want RTP traffic to be generated Brawse Each line in the p
30. 802 16 d WiMAX wireless networks DVB RCS satellite networks GPRS networks etc The detailed opera tions for these wireless networks will be illustrated in later chapters iz E is aT Cf h fma fee PSs ee eae Oo hh ae KH Reeve ee Be 2286 2 ETER r rea wl b AA be ln a aa F a Ra a eo a a r A329 A lt 2 DER P Ge oF Eo zi aj j i 0 on A CKD OD es es gt GAUA i leas Form an ITS Car Group The Form ITS cars group amp tool is used for a user to group several ITS cars into a fleet which is called a car group in NCTUns The cars in the same group will sequen tially follow the route taken by the head car of the group during simulation Forming a car group in NCTUns is easy One first left clicks the icon of this tool on the GUI tool panel He she then left clicks all the icons of cars in the working area that are chosen to form the same car group To end the selection of cars one can right click the mouse and a dialog box showing the IDs of the chosen cars will pop up Bee One should note that the first car that is chosen during the selection procedure will be automatically designated as the head car leading car Selecting cars into a car group should conform to the following rules First the cars that are chosen to form the same car group must be on the same road More specifically all of them must be on the same road between two turns Second they must be selected beginning with
31. A Transport Protocol for Real Time Application 2 RFC 1890 RTP Profile for Audio and Video Confer ences with Minimal Control 3 RFC 2327 SDP Session Description Protocol 4 RFC 2543 SIP Session Initiation Protocol 5 RFC 3551 RTP Profile for Audio and Video Conference with Minimal Control 12 GPRS Networks eneral packet radio service GPRS uses the existing G GSM cellular network to provide wide area end to end packet switched services The wireless range of a GPRS base station can be up to 35 Km but the provided data rate for a 3 1 downlink uplink time slots GPRS user is only about 36 12 Kbps for the downlink and uplink directions In this chapter we illustrate how to use NCTUns to conduct GPRS simulations GPRS Concept GPRS is provided on the existing GSM cellular networks to provide wide area data services A user can use GPRS to connect to the Internet for browsing web pages checking email downloading files receiving sending important messages when he she is away from his her office and home networks Because the coverage area of a GPRS base station can be very large the radius of the coverage area can be any number from Km up to 35 Km the data applications enabled by GPRS are well suited for users who are on moving vehicles or away from fixed networks In a GSM GPRS cell GSM voice traffic competes with GPRS data traffic for the channel bandwidth provided by the GS
32. A user needs to input a DS domain name at this time If the DS domain name for this new router is the same as a name that has been specified before the user can Select it from the DS domain name menu provided in this dialog box to avoid typing The following two figures show these operations goSs Domain Name Please specify the QoS domain name DomainA ET i yga oa bt oo Q Fee h Joo jj Tan J berg h ieg imio foe p Te TOET S ea eae yee aa E EE ine j e 2 Bone Fre iF9M LLAaALLa _ SALAS E Be Be RPeREs Fe Aaa 52 DER P The DiffServ boundary and interior routers that belong to the same DS domain will use the same set of traffic classifier conditioner and PHB for the packets passing through them Multiple DS domains can exist in a simulated network The rules and parameters for the DS domains existing in a simulated network should be specified in a configuration file and read by the GUI and the simulation engine This config uration file is a text file and can be edited by any editor such as vi or emacs A user can execute the Menu gt N_Tools gt QoS DiffServ Network gt Select Configuration File command to select it This file will be copied into the sim directory of this simulation case and renamed to dsdmdf txt The DiffServ related protocol modules will read the dsdmdf txt file during simulation The following figure shows the dialog box of this command 103 W DiffServ Configuration File Please s
33. BORER rr ad LLLA LH ALAALS FSER CKD BEEBE SHSer BE LALR DERP eee a mea mmmn AA HII mh 147 Setting Multi interface Mobile Nodes Insert Multi interface Mobile Nodes One can select the icon of the multi interface mobile node M and then left click the mouse in the field to add a multi interface mobile node After one left clicks the mouse the following dialog box will be popped up for users to specify which type of and how many radio interfaces to be added into this multi interface node As introduced earlier NCTUns now supports eight different types of wireless mobile interfaces that can be added into a multi interface node vv Select the interfaces that this multi interface mobile node is to be equipped with interface list tructure mode interface 1a ad hoc mode interface tructure mode interface ad hoc mode interface GPRS radio DVB RCST Return Channel Satellite Termina 802 1he mobile station An alternative is to use the automatic deployment tool to add a number of multi interface mobile nodes at a time The location of the automatic deployment tool for multi interface mobile nodes is Menu gt N_Tools gt Heterogeneous Network gt Insert multi interface Nodes The following figure shows the dialog box of this deployment tool v Mc Ibi le Now es Insert Multi interface m Insert Multi interface Mobile Nodes at random positions Insert Multi interface Mobile Nod
34. Burst Switched Networks IEEE ICC 03 International Conference on Communi cation May 11 15 2003 Anchorage Alaska USA 15 IEEE 802 11 b Wireless Mesh Networks ireless mesh network is composed of multiple WLAN access points that wirelessly forward mobile client stations packets Due to this archi tecture this type of network requires low wiring costs is decentralized reliable and resilient against access point failures In this chapter we present how to use NCTUns to simulate an IEEE 802 11 b wireless mesh network Wireless Mesh Networks Concept A wireless mesh network WMN is composed of mesh access points and standard infrastructure mode WLAN mobile client stations A client station uses the standard IEEE 802 11 b protocol to attach to and associate with a mesh access point for obtaining networking services In NCTUns two kinds of mesh access points are supported which are mesh OSPF access point running OSPF as the routing cunning the Spanning Tree Protocol as the routing protocol protocol and mesh STP access point In NCTUns a mesh access point has two IEEE 802 11 b wireless interfaces The first one operates in the infrastructure mode to serve standard WLAN client stations by while the second one operates in the ad hoc mode to wirelessly forward packets among mesh access points gb A WMN can connect to a fixed network such as an Ethernet or an optical network In such a case a mesh multi gat
35. However during the automatic IP address generation process the GUI program does not have the intelligence to know which subnet the user would like an infrastructure mode mobile node to belong to e g suppose that there are two access points each of which belongs to a different subnet As a result without the subnet relationship information the GUI program cannot intelli gently generate and assign an appropriate IP address to an infrastructure mode mobile node To help the GUI program solve this problem the user needs to manually select the involved infrastructure mode mobile nodes and the desired wireless access point to form a wireless subnet With this subnet grouping information the GUI program now knows the access point with which these infrastructure mode mobile nodes would like to associate As a result it knows the subnet ID that should be assigned to this wireless subnet and it can assign a unique and correct IP address to each of these infrastructure mode mobile nodes automatically With this design the user need not configure the gateway IP address for these infrastructure mode mobile nodes The GUI program intelligently knows this infor mation by tracking the access point back to the router that has a network interface connecting to this access point The IP address of this network interface is the gateway IP address for these infrastructure mode mobile nodes The following figure shows that the form subnet tool is u
36. IP address assigned to the lo loopback network interface In case the 127 0 0 1 IP address cannot work due to some unexpected reasons the user can replace it with the machine s own IP address e g 140 113 17 5 This setting should always work If a user is using the multi machine mode and the dispatcher is running on a remote machine the IP address specified should be the IP address of that remote machine 4 Start up the nctunsclient After all of the above steps are performed a user can now launch NCTUns s GUI program called nctunsclient This program is also located in usr local nctuns bin To run the GUI program successfully the user need not be the root user Draw a Network Topology After the starting screen of NCTUns disappears a user will be presented a working window shown below cn lon Tips Eis mii O_o fi D Beeg A eirg Geo poe oe e a ee ee ee ee E LE SERB Fr 7 _L LALLY SA a a Leap ae iG Beebe BEege ARR AARAL 2 DER PF a a 0 0 00 00 OO tao F a maa nea maat Fh CN HA P i m Hp g The working area of the topology editor To edit a new network topology a user can perform the following steps 1 Choose Menu gt File gt Operating Mode and make sure that the Draw Topology mode is checked Actually this is the default mode which NCTUns will be in when it is launched iw Draw Topology Run Simulation Play Back It is important to note that only in the Draw Topology
37. IP address to be 192 168 1 1 in the panel Menu gt G_ setting gt Dispatcher Now one can draw the network topology on the working area of the GUI After finishing drawing the topology one can switch the GUI to the Edit Property mode the E mode Preference Job dispatcher IP address 192 fiss fi fi Port 9800 User information hetu ns Password User name Email address The user name here cannot be root Otherwise the command console function cannot work correctly canca In the E mode one can set up the application programs that will be run during simulation For example we specify that the stcp p 8000 1 0 2 1 command should be run on the host with 1 0 1 1 and the rtcp p 8000 command should be run on the host with 1 0 2 1 One then double clicks the icon of the virtual router to pop up its dialog box In this dialog box one should enable the first option Use a real router to connect multiple emulation machines The detailed setting for this dialog are shown below Virtual Router External Router ID i Use a real router to connect multiple emulation n 192 168 1 1 192 168 2 1 192 168 1 1 192 168 2 1 Node editor Cancel After setting up the virtual router one can switch the GUI to the Run Simulation mode and start running the distributed emulation case The GUI will divide the emulated network into two parts
38. Inside an optical network only optical switches can be used Heanor to form the optical network and no other types of devices are allowed Two types of optical switches are currently From Host12 to Router7 From Router to Host12 supported in NCTUns The first one is called optical circuit Delay ho fag e aoe Cm fl us TAL crac us TAL rac switch while the second one is called optical burst Bandwidth CTAC Bandwidth Mb STAF switch They cannot be mixed to form an optical mamah fioo apy _GTAL orac Pma fomo Me oat crac network Instead an optical network can be formed by only BER pomon o crar crac SR poo orat orac one type of optical switches Down time Down time i EID Start s End s Start s End s Using the Wavelength Division Multiplexing WDM C a a ee Add technique an optical link is divided into several channels each operating at a different frequency or said to use a different wavelength In NCTUns when the first optical switch is added to the topology editor the GUI program will E La pop up a dialog box asking the user how many channels an FOR oea optical link has see the following figure In a NCTUns Delete Delete simulation case all optical links must have the same number Circuit Switching Optical Network 107 When an optical network is formed by optical circuit switches we call this type of network a circuit
39. LLET BE 453 8585 2 0ER P NCTUns 6 0 Topology Editor The topology editor provides a convenient and intuitive way to graphically construct a network topology A constructed network can be a fixed wired network or a mobile wireless network For ITS applications a road network can also be constructed Due to the user friendly design all GUI opera tions can be performed easily and intuitively Fis Eee G Te Aj To ey A ey Tmin yi ie XA eos ERD ea eee vaeea ps aeees GL oann Fr 9WILLALLS OLS ALSAALAY4 Sa Pe io eB eBECP BEY Aas Ge a DER P eT i G A a lee a 2 ma g OC Eaa m a ee 2 i ee ee oor Daim Pente The topology editor of NCTUns Attribute Dialog Box A network device node may have many attributes Setting and modifying the attributes of a network node can be easily done Just double clicking the icon of a network node An attribute dialog box pertaining to this node will pop up A user can then set the device s attributes in the dialog box Es bE D Tei H Pete G Sig jj Sete hie fee ee BAe B4 8 85 SRSA e LIJT ME LI S ECL TEV Fe Se LLALLA LE LL LeeLee eee aie BERBERS R Er SB AR RRS DERP i A EY P 0E DO Bs saa ae ranma ma sa AA A HA e D oe ia aiai Tage kims BO i mae i A popped up dialog box of NCTUns Performance Monitor The performance monitor can easily and graphically generate and display plots of some monitored performance metrics over time Examples
40. Linux system If thousands of agent programs need to be run up during a simulation their aggregate resource demands e g CPU cycles main memory etc may exceed those provided by the system and the simulation speed will be low In contrast a module controlled OBU is controlled by its own node module in the simulation engine A module is a C class with several member functions It is compiled and linked with the simulation engine code To control such an OBU one need not run up an independent process like one does for an agent controlled OBU As a result even though thousands of OBUs are simulated in a case one need not run up any process for them For this reason a simulation using module controlled OBUs greatly outperforms that using agent controlled OBUs on simulation speed and memory consumption However to develop a module controlled OBU one needs to know how to write modify an NCTUns module This is the disadvantage with this approach Because these two types of OBUs suit different applications for users convenience NCTUns provides both of them for users to best suit their respective needs The following figure shows the dialog box of an 802 11 p RSU which is composed of three tabs 1 IEEE 802 11 p Provider Setting 2 Application and 3 Mobile IP The Application and Mobile IP settings for an 802 11 p RSU are the same as those for an 802 11 b Access Point To save space we do not explain them here One can refe
41. Ss NCTUns 6 0 version 9 1 2009 tmp testi tp File Edt G Tools N Tools G Setting N Setting Simulation View Help BA eo7B 5 ae Be TFB JH LLALLA RAA AA ZM DERP ITTEN LOLLY LE SESBUSE SERED Reconnect Subm as Background Job 4 UU LAAJ LAAJ LAAJ y Select Node ID 1 3 E root locahost NC B root bocahost usr NCTUns 6 0 version 9 E root localhost 5 When the simulation server is executing the user will see the time knot at the bottom of the screen move The time knot reflects the current simulation time progress of the simulation case Currently the maximum time that can be simulated for a simulation case is set to 4 200 seconds Playing Back the Packet Animation Trace After the simulation is finished the simulation server will send back the simulation result files to the GUI program After receiving these files the GUI program will store these files in the results directory It will then automatically switch to the Play Back mode 16 To save the network bandwidth and time required for trans ferring these huge files across a network these result files are tarred using the tar command and gzipped using the gzip command into a tar ball before being sent to the GUI program This usually can reduce the bandwidth usage by a factor of 10 or above After receiving the tar ball the GUI program needs to untar and ungzip the tar ball before using these files A
42. State Transition Selecting this option specifies that the performance curve should be drawn using horizontal lines to connect adjacent points In addition to the above settings a performance curve s legend and color can be easily set by double clicking the curve s legend located at the top right corner For example a user can double click the default graph X curve legend to change it Global Setting Executing this command can associate a graph data source file with a log file Up to six associations can be specified in this dialog To select a log file from the local host a user can press the Browse button V Global Setting ao G Graph File Source f Source 0 E O Source 3 Source 1 Source 4 Source 2 Source 5 Browse OK Apply Cancel Graph Mode Executing this command can control how to display a perfor mance curve Currently there are two modes The first mode is line points while the second mode is state transition The following two screen shots clarify the differences between these two modes 54 Window Color Option Graph Title Grapl EENEN r oe on d oo coo LD COO Co Lue coo es ho Koon GLE ae E 0 0 2 0 04 0 6 7 8 0 0 T we The performance curve is plotted using the line point format W roottestpetormancepetormance resultspertormance 8023_N1 G G Eile Window Color p
43. a NCTUns emulation machine in real time NCTUns can emulate a very large network with many real world appli cation programs launched on it and many real world devices attached to it The scale of such a distributed emulation can be very large and is only limited by the number of available machines that can participate in the distributed emulation The dsitributed emulation approach of NCTUns is a fully automatic approach that needs no manual modifications to configuration files for performing a distributed emulation To perform a distributed emulation in NCTUns one first decides how to partition the emulated network into several parts Then one uses the GUI to construct the network topology of each part Finally one uses the virtual router which represents a real router or a crossover cable between two parts to connect any two parts together where appro priate After these operations the GUI will intelligently and automatically generate appropriate network configuration files and send them to all emulation machines participating in the distributed emulation When the distributed emulation is done the GUI will collect simulation result files and packet log files from all participating emulation machines and intelligently merge these files together as if the emulation were totally performed on just one machine Using NCTUns a user need not worry about how to modify the contents of the generated network configuration files to correct
44. add net 200 3 1 0 24 gw 192 168 1 1 route add net 200 3 2 0 24 gw 192 168 2 1 The rationale for executing these commands on the real router is explained here A packet with a destination IP address 200 Z X Y indicates that this packet is from a subnet of 1 0 Z 0 24 To be precise Z does not denote the ID of the original source subnet of the packet but rather the ID of the last subnet on which the packet traverses before it is sent to this real router and destined to a subnet of 1 0 X Y For example the first route command will make the real router forward packets generated from the 1 0 1 0 24 subnet and destined to the 1 0 2 0 24 subnet to the real machine with the IP address 192 168 2 1 which is designated to emulate the subnet of 1 0 2 0 24 The next step is to run up the dispatcher program In this example we run up it on the emulation machine with the IP address 192 168 1 1 One then modifies the coordinator cfg file on each emulation machine for the coordinator program running on this emulation machine Because the dispatcher program is run on the emulation machine with the IP address 192 168 1 1 one should change the DISPATCHER_IP parameter in each coordinator cfg file from 127 0 0 1 to 192 168 1 1 so that each involved coordinator program can correctly register itself with the same dispatcher program After this is done one can run up all involved coordinator programs on their respective emulation machines After startin
45. and send the configuration files for each part to the emulation machine responsible for it 67 Use a direct link to connect two emulation machines If the virtual router does not represent a real router it can represents a crossover link or a switch As shown in the following figure the two emulation machines are directly connected via a crossover Ethernet cable Using this physical network configuration the virtual router is not mapped to any real device in the real world Topology Emulation Machine 192 168 1 2 Emulation Machine 192 168 1 1 In this example case the dispatcher program and the GUI program are run on the emulation machine with the IP address 192 168 1 1 That is the dispatcher command is executed on the emulation machine with the IP address 192 168 1 1 One then modifies the coordinator cfg files for all involved coordinator programs Because the dispatcher program is run on the emulation machine with the IP address 192 168 1 1 one should set the DISPATCHER_IP parameter in each coordinator cfg file from 127 0 0 1 to 192 168 1 1 so that each coordinator program can correctly register itself with the same dispatcher program After this is done one can run up all involved coordinator programs on the two emulation machines The fourth step is to run up the GUI program on the emulation machine with the IP address 192 168 1 1 and set the Dispatcher IP address to 192 168 1 1 in the panel Menu gt
46. are the same as their counterparts on the first panel To save space we do not explain them again here 65 After a distributed emulation case is properly set up one can click the Run Simulation mode At that time the GUI program will Run Simulation button to enter the generate emulation related files for the whole emulation case The detailed setting on each real machine for emulating a part of the whole network is explained later In the following we first briefly explain the architecture of NCTUns for distributed emulations Distributed Emulation Architecture NCTUns employs a central controller to manage all emulation machines for a distributed emulation case The functions of the central controller are implemented in the GUI program and the dispatcher program The GUI program is also called the main controller in terms of the distributed emulation architecture The architecture of NCTUns for distributed emulations is shown in the following figure Main Controller NCTUns GUI Request specific coordinators Reply coordinators Dispatcher Register Emulation Machine Coordinator Emulation Machine Coordinator Emulation Machine Coordinator Emulation Machine Coordinator Setting Up a Distributed Emulation Case Before a distributed emulation case can be performed the dispatcher program should be launched on a machine After that on each participating emulation machine one s
47. as a background job to the dispatcher for execution Its effect is the same as first running up the simulation and then immediately discon necting the GUI from the just launched simulation job To reconnect to a currently running background job or retrieve results from a finished background job the user should use the Menu gt File gt Background Job Management command 4 View Messages from Simulation Engine NCTUns provides a runtime messaging mechanism to enable protocol modules to dynamically send messages to the GUI program during simulation In the Run Simulation mode when the GUI program receives a message from a protocol module it will pop up a window to show the received message The following figure shows a snapshot of the popped up window Y Tousa G Setting M Setting Simulation View Help w bA SICA LTI LELIE eC ESSA Lees i een sn PL LGALLGINL STILL LES ERR 2 BALE EERE eR ae eS ee T itme ER P x Tima 2 19 Node ID 2 Module BS 16 NT_ Scheduler Massage BS 2 ULAalay UGSScheduling UGS allocation exhausting allocSloise75 availableStots 116 Lox J 000 000 000 000 Node iD 1 080 000 000 000 A A Hd gt I a fors 971 682 After the simulation is completed one can use the command Menu gt G_Tools gt View Messages from Simulation Engine to review the messages issued by protocol modules in the Play Back mode The snapshot of this tool is shown below Boot G0 wiral ALS r
48. b g networks To clarify these steps in this section we explain in detail the node types of the IEEE 802 11 p network supported in NCTUns demonstrate the dialog boxes of these nodes and explain the meanings of the parameters shown in their dialog boxes Node Types of the IEEE 802 11 p Network As shown in the following figure NCTUns supports IEEE 802 11 p OBUs and RSUs The 802 11 p OBU is further divided into two types based on which component controls its moving behavior and possibly generates messages The icon marked with an a denotes an agent controlled 802 11 p OBU which means that the moving behavior and message delivery of this OBU are controlled by a real life car agent program On the other hand the icon marked with an m denotes a module controlled 802 11 p OBU which means that the moving behavior and message delivery of this OBU are controlled by the node module of this OBU in the simulation engine Ea Fa Ph The icons of the 802 11 p OBUs and RSU These two OBU types have their respective advantages and disadvantages An agent controlled OBU is controlled by an agent program which is essentially a normal real life appli cation program Writing such an agent program is very easy and is the same as one writes a normal application program on the Linux system However the disadvantage with the agent controlled approach is that each agent program will be run up as an independent process on the
49. be properly set The first one is for setting up the communication between the GUI central controller and each coordinator program in the real world The second one is for setting up the communication between hosts in different parts of the emulated network The first type of the route commands required for this example case is shown as follows Router with IP address 192 168 1 254 and 192 168 2 254 route add net 192 168 3 0 24 gw 192 168 2 1 route add net 192 168 4 0 24 gw 192 168 2 1 Router with IP address 192 168 3 254 and 192 168 4 254 route add net 192 168 1 0 24 gw 192 168 3 1 route add net 192 168 2 0 24 gw 192 168 3 1 Emulation machines with IP 192 168 2 1 and 192 168 3 1 route add net 192 168 1 0 24 gw 192 168 2 254 route add net 192 168 4 0 24 gw 192 168 3 254 The second type of the route commands required for this example case is shown as follows Router with IP address 192 168 1 254 and 192 168 2 254 route add net 200 1 2 0 24 gw 192 168 2 1 route add net 200 1 3 0 24 gw 192 168 2 1 route add net 200 2 1 0 24 gw 192 168 1 1 Router with IP address 192 168 3 254 and 192 168 4 254 route add net 200 2 3 0 24 gw 192 168 4 1 route add net 200 3 1 0 24 gw 192 168 3 1 route add net 200 3 2 0 24 gw 192 168 3 1 The rationale for executing these commands on a real router is explained here A packet with a destination IP address 200 Z X Y indicates that this packet is from a subnet of 1 0 Z 0 24 To be precise Z do
50. button to save these parameter values into a SDP file The file name of this newly created file or the existing file must be put into the SDP file name field so that the selected RTP program can find and read it Putting the SDP file name into this field can be done manually or via the Browse to select one if it exists button The rtpsendrecv example program uses a fixed rate to send its RTP packets If a user wants this program to send out its RTP packets based on a packet trace file he she can turn on the Select packet trace file option at the bottom of the RTP dialog box and select a file for it The format of the packet trace file is simple Each line in the packet trace file repre sents a packet that should be transmitted and has two columns The first column is the packet size in byte while the second column is the interval time which is in second and can be less than 1 such as 0 01 between this packet and the next packet This option is useful for transferring a real world media file such as a MPEG 2 movie stream over a simulated network SDP Information Email address RTCP packets should be sent every should be sent every fi 600 kbps fo sec to m Destination IP address es fo PCMU 8000 8 audio IP address audio x Add 5004 Delete fo H Pemu 2000 E 20 Please reference RFC 3551 for explanations of these parameters p 4 p 4 Phone number RTCP packets S
51. e adds several mechanisms such as timing adjustment continuous ranging Mobile Station MS handoff etc to support user mobility NCTUns 6 0 supports the IEEE 802 16 e network In this chapter we present how to conduct a simulation of an IEEE 802 16 e network using the GUI program IEEE 802 16 e PMP Mode Concept An IEEE 802 16 e PMP mode network is composed of two types of nodes The first is the Base Station BS Bs which is responsible for allocating network resources and coordinating uplink transmissions while the second is the Mobile Station j which is a mobile node that is equipped with an 802 16 e radio and can run application on it Since the IEEE 802 16 e network is an All IP network to support user mobility it employs the mobile IP scheme to deal with the issues of user mobility at the network layer The following two figures show the dialog boxes of an 802 16 e BS node and an 802 16 e MS node respectively The detailed instructions for configuring Mobile IP for this network can be found in the Mobile IP chapter V IEEE 80216le BS in PMP Mode Enable Mobile IP IEEE 802 16 e PMP mode Base Station M IEEE 802166 Mobile Station in PMP Mode Application Mobile IP Start time s Stop time s Command Input file Name Add Modify Delete App Usage
52. ee Oe Bee ee ee ee gt h g A 3 a Ma KER P there mamn AA Ii a bf Bm external host to run up the TCP sending program The following figure shows this network and traffic configu ration Eip pai G Toor H TRENE m or i mor Wow Hep XAeoeVth elo BS oVveeyivag Aua a i ie BOMB er FOIL OAL SIL GALSALS Sa eee BOSCBOWEEE BRAUAARRRs aIDERP CP connection If the external host is physically connected to the simulation machine and its routing configuration has been properly set according to previous explanations TCP packets will begin to be exchanged between the simulated host and the external host The following figure shows the physical setup for this emulation case Second suppose that the simulated host wants to make a greedy TCP connection to the external host In such a case the rtcp p 8000 command should be first run up on the external host waiting for the TCP connection setup request to come Then the stcp p 8000 1 0 2 1 command can be entered to the Application tab of the simulated host s dialog box Doing so will run up a TCP sending program on the simulated host during the emulation When the emulation starts TCP packets will begin to be exchanged between the simulated host and the external host a b w J I ows gt t DOCA 2 uw SSBe GK Ve WV wwe asuy tea rrp re J D st p 9j Ss gt L Hw BeBaesees DRA a m aa A DERP Must on the same subnet Delay As
53. file packet transfer trace should be generated or not The user can further select which types of network s packet transfers should be logged into the ptr file The random number seed given to the simulation engine for this simulation case can also be specified Using the default value of O indicates to the simulation engine that it can choose a random number for the random number seed That is each time the same simulation case is run a different random number seed will be used If the random number seed is fixed to a value greater than 0 NCTUns can generate repeatable results for each run of the same simulation case Simul ation 2 LA Lx Simulation Speed Real Time GUI GDB De gt Simulation time Iso sec Max 3000 meter Max 13000 meter Max_z 3000 meter M Generate packet animation log file ptr M Fixed Internet M Wireless LAN M GPRS network M WiMax network w MobileWiMax network YY MobileRelayWiMax network transparent rr M MobilleRelayWiMax network non transpare e Random Numbers 0 Using the default value 0 means that the seed will be automatically generated OK Cancel Under the Speed tab the tick time can be specified The default setting is that one tick represents 100 nanoseconds in virtual time in a simulation This setting can be changed to a smaller value such as 10 or 1 nanosecond which is useful for generating more accurate results on high speed networks e g wit
54. follows h Ta n i JoJule Edit Parameters Setting Channel ID 2 Frequency MHz 2300 Cancel Transmission Power dbim 130 Receive Sensitivity dbm 99 The dialog box of the OFDMA_PMPBS_WIMAX module Summary In this chapter we conceptually introduce the IEEE 802 16 e network and present the steps required to configure a network case of this new network type over NCTUns In addition several useful commands and important dialog boxes for this network type are also explained 159 23 IEEE 802 16 WiMAX Networks The IEEE 802 160 specification is gaining much attention recently due to its several advantages over the preceding IEEE 802 16 e network In this network with the multi hop capability a packet is allowed to traverse two hops through relay stations to reach its destination node Thus by properly arranging the transmission path of a packet the capacity of the network and the signal quality experienced by users can be greatly improved against other communication technol ogies The IEEE 802 160 relay mode specification defines two operational modes the transparent mode and the non trans parent mode NCTUns supports both of these two opera tional modes In this chapter we present the detailed GUI operations to conduct simulations of the IEEE 802 160 transparent mode and non transparent mode networks IEEE 802 16 j Transparent Mode Concept An IEEE 802 16 j transparent mode networ
55. forth Users can choose one of them to simulate wireless channels by choosing the items shown in the list V Module Edit r Parameters Setting r Propagation Channel Mode Theoretical Channel Model Path Loss Model Two Ray Grou Fading Variance tioi Average Building Height m 10 hoo Average Building Distance m jo Street Wath m 30 0 Path Loss Exponent b 0 shadowing Standard Deviation h 0 Close in Reference Distance m q 0 System Loss 0 Antenna height m hs Ricean Factor K db 110 0 Cancel Fading Model None C Empirical Channel Model Suburban_1_9GHz_TB 88 w Enecaty physical layer ond channel sodel parameters Propagation Channel Model Theoretical Channel Model Path Loss Model 1 Two Ray Ground Fading Model oO None Empencal Chance Model Node Conmecinvdy Greplny Use the transmitting node perspective e Use the recenany node perspective Noce Connecty Determinatie Determined by power threshold Determined by distance Show Antenna Gain Pattern and Drectniy Recalculate RzAntennaHesgh m 15 CTA of a eenghboring mode r 250 CAPT dpm CPS TAN i Cinc CLR of a neighbenng node mi cai CC 5 P T dbm Summary In this chapter we explain the usage of the Specify physical layer and channel model parameters ee yY tool in detail Via this tool one can easily configure the properties of nodes antennas e g the operating frequency the point
56. include a link s utilization or a TCP connection s achieved throughput Because the format of its input data log file uses the general two column x y format and the data is in plain text the performance monitor can be used as an independent plotting tool Eis p r OLT Tein G i hig an Yee Liew To EOreEI TIGEL TALT EERE BOS rr S7W L ETE N e E G e a betbtpbibzs pt BEY Aa SSNDERP Tan ZN al rAr ii f k 5 j Es Wingy Gao Orr P E i i m m m m y Soe OSS 356 Bait kamim gi 1 enma A A ee Se The performance monitor of NCTUns Node Editor The node editor provides a convenient environment in which a user can flexibly configure the protocol modules used inside a network node By using this tool a user can easily add delete or replace a module with his her own module This capability enables a user to easily test the performance of a new protocol Using the node editor a user can also conveniently set the parameter values used by a specific protocol module Each box in the node editor represents a protocol module A user can double click a protocol module box to pop up its parameter dialog box Regarding how to add a new protocol module to the node editor 1 e to let it know that a user has added a new protocol module to the simulation engine readers should refer to the The Protocol Developer Manual for the NCTUns 6 0 Network Simulator and Emulator FIFO FIFO FIFO QoS
57. indicates that this packet is from a subnet of 1 0 Z 0 24 To be precise Z does not denote the ID of the original source subnet of the packet but rather the ID of the last subnet on which the packet traverses before it is sent to this real router and destined to a subnet of 1 0 X Y For example the first route command will make the real router forward packets generated by the 1 0 2 0 24 subnet and destined to the 1 0 1 0 24 subnet to the real machine with the IP address 192 168 1 1 which is designated to emulate the subnet of 1 0 1 0 24 The next step is to run up the dispatcher program on the emulation machine with the IP address 192 168 1 1 The third step is to properly modify the coordinator cfg file for all involved coordinator programs Recall that the dispatcher program is run on the emulation machine with the IP address 192 168 1 1 Thus one should modify the DISPATCHER_IP parameter in the coordinator cfg file from 127 0 0 1 to 192 168 1 1 for each involved coordinator program on each emulation machine so that each coordi nator will correctly know where the dispatcher program is and register itself with the same dispatcher program After properly modifying the coordinator cfg files for all involved coordinator programs one can run up these coordinator programs on their respective emulation machines The fourth step is to run up the GUI program on the emulation machine with the IP address 192 168 1 1 and specify the Dispatcher
58. inserted how many access points should be inserted and which positioning style random or array style should be used If a user wants to change the protocol stack of the mesh access points to be inserted this job can be done here V Insert mesh Access Points Insert mesh APs at random positions Insert mesh APs array Top left position X 20 Y 80 Dimension Row fi Column fi AP spacing 200 meter Protocol stack At random positions mesh APs Node edit Create Protocol stack Routing Protocol Used OSPF Node editor Cancel Spanning Tree Protocol Set Dual Radio Frequency Channels for Mesh AP Each mesh access point has two wireless interfaces One is operating in the ad hoc mode while the other is operating in the infrastructure mode By default the infrastructure mode interface uses the same frequency channel as the default frequency channel used by an infrastructure mode mobile node This configuration allows infrastructure mode mobile nodes to connect to mesh access points without any configu ration change If a user wants to change this default setting for a few mesh access points he she can enter the node editor of these mesh access points one by one to modify the frequency channel setting of the used WPHY modules If many mesh access points need to be changed a more convenient way is Wireless Mesh Network Protocol Stac
59. into a text file for inspection a printPtr utility program is provided in usr local nctuns bin In addition the user can also execute the GUI s Menu gt G_Tools gt View Packet Trace command to view a simulation case s ptr file When the GUI program has untarred and ungzipped the ptr file it will automatically switch to the Play Back mode In this mode the control buttons of the time bar located at the bottom of the screen can be used to play stop pause continue jump forward jump backward or intelligently jump forward the animation The user can also use the mouse to directly move the time knot to any desired time to see the packet transfers occurring at that moment To precisely move the time knot to a specific time the user can even double click the time display 1 e the LCD clock display area to pop up a window In this window the user can directly enter the desired time in ticks For example if the user wants to see the packet transfers occurring at 1 2345678 seconds then he she can enter 12345678 into this window The default mapping between 1 tick and its corresponding time duration in simulation time is 1 tick gt 100 nanoseconds This mapping can be changed by Menu gt G_Setting gt Simulation gt Speed for high speed networks such as 1 Gbps optical networks To start the playback the user can left click the start icon gt of the time bar located at the bottom The animation play
60. k E g oh To configure the receiving sending point at the Satellite node one can pop up the node editor of the Satellite node first After double clicking the DVBS2_SAT module box one will see a dialog box like what is shown below On the left hand side of the box one can set up the receiving Rx antenna related parameters such as antenna length and antenna efficiency and the sending Tx antenna related parameters such as Tx power antenna length and antenna efficiency V Module Edit Return Link TX TX Forward Power w Return Power 10 w Forward SAT Antenna Length 0 8 im Return SAT Antenna Length 0 8 m Forward SAT Antenna Efficiency 0 55 Return SAT Antenna Efficiency 0 55 RX RX Forward SAT Antenna Length 0 8 Return SAT Antenna Length 0 8 m Forward SAT Antenna Efficiency 051 Return SAT Antenna Efficiency O51 X Link Failure See Down Time Setting OK File Name rard Dvbs2_sat_N1_PLlinkfail Cancel To configure the receiving point at a RCST node one can pop up the node editor of the RCST node first After double clicking the DVB_S2_RCST module box one will see a dialog box like what is shown below On the left hand side of this box one can set up the LDPC Low Density Parity Check code iteration threshold and the antenna related parameters such as ground station antenna length and ground station a
61. learn how to run up his her first simulation case In later chapters the functions and capabilities of the GUI program will be explained in more detail In the next chapter we will begin with the topology editor 3 Topology Editor uilding a network topology is the first step toward running a simulation It can be easily done through the use of the topology editor of NCTUns This chapter will show you how to quickly build a network topology by using the topology editor Four Operating Modes Menu gt File gt Operating Mode gt Draw Topology Edit Prop erty Run simulation Play Back lv Draw Topology Run simulation Play Back NCTUns has four operating modes A user needs to switch the mode at proper times to make the topology editor work correctly Mode 1 Draw Topology In this mode a user can add new nodes links or delete nodes links to construct a network topology If the moving path of a mobile node needs to be specified before the simulation starts this path specification job must be done in this mode Note that for the mobile nodes in the active and tactic mobile ad hoc networks and the mobile cars in the Intelligent Transportation Systems ITS their moving paths are not specified before the simulation starts but rather are dynamically changed during simulation More information about these two types of networks e Tactic and ITS will be discussed in later chapters Mode 2 Edit Property In this mo
62. machine the IP address of the interface connecting to link is 140 113 1 1 in the real world the interface connecting to link2 is 140 113 2 1 and the interface connecting to link3 is 140 113 3 1 These address settings are best viewed by the above figure For this example case on the external router we need to execute the following routing commands to add the required entries On FreeBSD route add 200 1 1 1 140 113 1 1 route add 200 2 1 1 140 113 1 1 route add 200 3 1 1 140 113 1 1 route add 200 1 2 1 140 113 2 1 route add 200 2 2 1 140 113 2 1 route add 200 3 2 1 140 113 2 1 route add 200 1 3 1 140 113 3 1 route add 200 2 3 1 140 113 3 1 route add 200 3 3 1 140 113 3 1 On Linux route add 200 1 1 1 gw 140 113 1 1 route add 200 2 1 1 gw 140 113 1 1 route add 200 3 1 1 gw 140 113 1 1 route add 200 1 2 1 gw 140 113 2 1 route add 200 2 2 1 gw 140 113 2 1 route add 200 3 2 1 gw 140 113 2 1 route add 200 1 3 1 gw 140 113 3 1 route add 200 2 3 1 gw 140 113 3 1 route add 200 3 3 1 gw 140 113 3 1 These commands have the effect that all packets that originate from subnet 1 2 or 3 and go to 1 0 1 1 will be sent to 140 113 1 1 via link1 Similarly these commands have the effects that all packets that originate from subnet 1 2 or 3 and go to 1 0 2 1 will be sent to 140 113 2 1 via link2 and all packets that originate from subnet 1 2 or 3 and go to 1 0 3 1 will be sent to 140 113 3 1 via link3 If there are multiple hos
63. machines are not accurately synchronized using the NTP protocol the timing differences among them will be large which will worsen the packet log timestamp causality problem discussed above Summary This chapter shows the detailed steps to run a distributed emulation case First one should properly set the physical links to connect all emulation machines together according to the topology of the specified network Then one should properly configure the settings of the dispatcher program and that of each coordinator program running on different emulation machines Finally in the GUI program one needs to properly use the virtual routers to specify the partition points of the network topology before the distributed emulation case is started 9 Mobile IP obile IP protocol allows an infrastructure mode mobile host to leave its home network subnet and roam into a foreign different network subnet without breaking its current connections NCTUns supports Mobile IP including its basic scheme and the more advanced scheme called route optimization We detail how to use Mobile IP protocol in this chapter Mobile IP Concept The entities involved in Mobile IP are mobile host corre spondent host home agent and foreign agent Normally home agent and foreign agent programs run on routers and connections are created between the mobile host and the correspondent host on the fixed network The goal is to keep the connection w
64. mance analysis of IEEE802 11la b operating at 2 4 and 5 3 GHz proceedings of 10th Asia Pacific conference on communications 2004 pp 133 136 14 B Yesim HANCE and I Hakki CAVDAR Mobile Radio Propagation Measurements and Tuning the Path Loss Model in Urban Areas at GSM 900 Band in Istanbul Turkey IEEE Vehicular Technology Conference VTC2004 pp 139 143 Fall 2004 15 G Y Delisle J Lefevre M Lecours and J Chouinard Propagation loss prediction a comparative study with application to the mobile radio channel IEEE Transactions on Vehicular Technology 26 4 295 308 1985 89 11 RTP RTCP SDP R traffic such as audio and video This chapter illustrates how to use NCTUns to conduct RTP RTCP SDP simulations eal time transport protocol RTP RTP control protocol RTCP and session description protocol SDP are commonly used to transport real time RTP RTCP SDP Concepts RTP is a transport protocol for transporting real time data such as audio and video It can be used to provide the voice over IP VoIP service RTP is composed of a data and a control component The control component is called RTCP The data component of RTP is a simple protocol that provides support for real time applications e g an audio and or video server The support includes timing reconstruction packet loss detection data security and other functions RTCP on the other hand provides support for real time conf
65. maxgqlen otherwise it remains a BE packet and is enqueued QueAdd specifies how much bandwidth and memory buffer resources of an interface should be allocated to a PHB service The type field specifies the PHB service The name field specifies the name of this service which is not important and can be the same as the type For example it can be specified as gold silver or bronze The weight field affects the amount of bandwidth that is allocated to this PHB The actual amount is a fraction of the interface bandwidth This fraction is the ratio of weight to the sum of all weights specified in all QueAdd lines For example suppose that 104 there are four QueAdd lines and the weights of these queues are 1 2 3 and 4 respectively Then queue 1 will be allocated 1 1 2 3 4 1 10 of the interface bandwidth The maxglen field specifies the maximum queue length allowed for the queue used to buffer packets marked with this PHB s codepoint The ts ts2 and MDR fields are meaningful only for AF traffic The ts and ts2 specify the low threshold and high threshold of the queue length They are used to provide different packet dropping probabilities for different dropping precedences inside an AF class The current queue length is compared against these two thresholds to determine the packet dropping rate for incoming packets Using the AF1 class as an example when the current queue length is greater than ts AF11 packets will star
66. mobile IP usage example Using Mobile IP In the following we show how to enable the Mobile IP function in NCTUns Correspondent Host Application Down time Mobile IF RO Port Command console Mode editor OK Cancel In the Mobile IP basic scheme the correspondent host need not do anything However if the correspondent host wants to use the more advanced Route Optimization scheme the Enable Route Optimization RO option must be checked Since an RO agent daemon needs to be run on this host the user must specify a UDP port number for this daemon This port number should be different from all port numbers used by other daemons Infrastructure Mode Mobile Host If the mobile host wants to use Mobile IP the Enable Mobile IP option in the following figure needs to be checked Also the user needs to specify the IP address of the router where this mobile host s home agent resides Using the above example network to illustrate the IP address here should be the IP address of the bottom interface of the left router The user also needs to provide the IP address used by this mobile host to the mobile agent This information is needed in the Mobile IP protocol because the mobile agent needs to register its own IP address with its home agent V mobile station a G Mobile ID 9 Co mman q conso Z Name IMNODES Path
67. module A by protocol module B in that node s protocol stack 4 The user uses the C P A N S T button to replace the parameter values including the protocol stacks of all other mobile nodes with the new one 5 Finally the user runs the new simulation case and obtains the perfor mance results of protocol module B under the same network topology and configuration Note that the above task can also be easily done by executing Menu gt G_Tools gt Export Mobile Nodes and Their Paths to File and Menu gt G_Tools gt Import Mobile Nodes and Their Paths from File commands and Menu gt G_Tools gt Import Network Traffic Application File command Detailed instructions on these commands will be presented later in this chapter e WAN Wide Area Network Abstraction Down time Start s Node editor OK Cancel A WAN 1s a layer 2 node that simulates various properties of a Wide Area Network It can purposely delay drop and or reorder passing packets according to a specified distribution Inside the simulation engine a WAN is implemented as a layer 2 switch with only two ports The packet dropping delaying and reordering functions are achieved via the WAN module used inside a WAN node In a WAN node a WAN module exists in each of its two ports It delays drops and or reorders the port s outgoing packets The forward and backward packets of a flow that traverse a WAN can t
68. network To describe the connectivity between an external host router and a simulated network 1 e to specify to which node in the simulated network the external host router is attached each real world external host router is represented as an external host router icon in the simulated network A GUI user can easily specify to which node in the simulated network an external host router should connect by drawing a link between these two nodes Like all other links in the simulated network such a link has its own properties and is simulated by NCTUns To let the packets generated by an external host enter the simulated network or let an external host receive packets originated from the simulated network the external host must be physically connected to the simulation machine via some network which can be as simple as an Ethernet cable Ideally such a network should have infinite bandwidth and zero latency Although in the real world such a network does not exist for achieving accurate results the used network should still have low latency and high bandwidth For example a 100 Mbps Fast Ethernet network may be used for this purpose One should notice that for NCTUns an external host must reside on the same subnet as the simulation machine otherwise the emulation function will not work properly NCTUns uses an emulation kernel module to seamlessly bridge the real life network and the simulated network This kernel module performs
69. network and the WAVE mode operation We then present how to configure an EEE 802 11 p network in NCTUns EEE 802 11 p specification is an amendment to The Concept of an ITS Network An ITS network is an integrated platform that combines the road network and a communication network The infor mation related to the road network and vehicle statuses can be distributed over moving vehicles in such a network using radios Such an integration enables many new applications in the transportation network and the communication network e g improving the safety of vehicles and pedestrians and improving the communication quality among vehicles in a highly mobile vehicular network To satisfy the increasing needs of simulating such ITS networks NCTUns provides a complete solution to simulate an IEEE 802 11 p vehicular network Differing from other solutions which usually connect the road network simulation and the communication network simulation in a loosely coupled manner NCTUns tightly integrates the simulations of a road network and a communication network Due to this unique advantage NCTUns is now a useful tool for the ITS research community More information about the NCTUns capabilities on ITS researches can be found in the paper NCTUns 5 0 A Network Simulator for IEEE 802 11 p and 1609 Wireless Vehicular Network Researches which is published in the 2nd IEEE Interna tional Symposium on Wireless Vehicular Communications
70. node generates the maximum gain value in the 90 degree direction meaning that the relative angle between the antenna pointing direction and the 90 degree direction is zero As such we can obtain the gain values over the 360 degrees by using the following transformation Di Gi gt Di Dpoint mod 360 Gi where Di Gi denotes the i th entry of the antenna gain pattern file In each entry Di denotes the i th degree of the antenna relative to its pointing direction and Gi denotes the gain value of the antenna in dBi at the i th degree Dpoint denotes the angle of the antenna s pointing direction Us wORSoWUVUBUVVUs BFSBuiae ec BEEBE iLL amp M PSA e KO BESBSBSEEs BS BH DERP The point direction of mode 1 s antenna is the 90 degree direction The polor coordinate system from a node s perspective The maximum gain valse ts ach eved in the 9 degree direction gt E 180 90 270 anA A MDP Uw plese ison The second example is shown in the following figure where nodes and 2 are equipped with the default 120 degree and 60 degree directional antennas provided by NCTUns respectively The gain patterns of these two default direc tional antennas have been given previously The pointing direction of node 1 s antenna is 180 degree and that of node 2 s is O degree Under such a configuration when node 1 transmits a packet to node 2 its antenna gain is 10 61975932 called Transmiss
71. node is moving from one point to the next point 1 e moving on a segment its moving speed is fixed If a user moves the icon of a mobile node rather than one of its turning point boxes its whole moving path will be moved There are several other tools on the tool bar They are select k delete X label A arrow i undo 9 Zoom out Q zoom into an area el Set the zoom scale factor to 1 specify physical layer and channel model parameter 5 ruler Zoom in view the whole tield and protractor measure the angle between a specified line segment and the horizon W The select function is the most basic operation If a user wants to move a device icon he she must select this tool first He she then presses the mouse s left button on the device icon holds it and then drags it to the desired place In addition if a user wants to configure a device in the working area he she should use the select tool to double click it The delete function can delete a touched node and all the links connected to it The undo function can undo the last delete operation It is a useful function because human sometimes make mistakes and it may take much time and effort to recover from a mistake For example if a user mistakenly deletes a router that has 20 links each connecting to a host the router and these 20 links will be deleted To recover from this mistake without using the undo too
72. node movement and packet transmissions during a tactical MANET simulation Summary In this chapter we give a conceptual introduction to the tactical and active mobile ad hoc network an example scenario of such a network and how NCTUns supports tactical and active mobile ad hoc network simulations Besides we explain the attributes of an obstacle which is an essential component used to model a battlefield in the real world Finally we illustrate the necessary operational steps for running up a tactical and active mobile ad hoc network simulation in NCTUns 124 amp Satellite Networks providing channels for a GEO Satellite to interact way data exchanges between service providers and end 18 DVB RCS VB RCS Digital Video Broadcasting Return D Channel Via Satellite is a well known standard with fixed RCSTs Return Channel Satellite Terminals on the ground A DVB RCS system enables two users As such Internet protocols such as TCP IP and UDP IP can operate in DVB RCS systems Network Nodes The following figure shows from left to right the seven kinds of network nodes comprising a DVB RCS network SP Service Provider NCC Network Control Center RCST Return Channel Satellite Terminal Feeder TG Traffic Gateway Satellite and Pseudo Switch aye eS RB The NCC is the central controller of the whole DVB RCS network It is responsible for managing the use of the channel resource on the forward link and the retur
73. oan rr d 18 RAAT FSERE RO IAQ we DERP BOSROYEED The following figure shows the format of the MS node QoS provision table Note that the current IEEE 802 16 e imple mentation in NCTUns only supports the best effort traffic Un granted service As such the only parameter required for each MS node s QoS provision is the sustained rate in Kbps which denotes the maximum link bandwidth that this MS node is allowed to use Qos Provision for Mobile Stations Gos Provision Table WS Node ID Sustained Rate Kbps 1000 1001 Modify Delete Cancel IEEE 802 16 e PMP Network Protocol Stack The settings of IEEE 802 16 e related protocol modules can be specified via the Node Editor The following figure shows the default protocol stack of an 802 16 e BS node 158 MAC80211 weuy so2up AP ARP DVB_S2_FEEDER DVB_S2_RCST Fwo Guu 4 gt MAC8021 MAC8021 MAC8021 gt 80211e K Select Mode k JC f Cancel The protocol stack of an IEEE 802 16 e BS Node By double clicking an icon of a module inside the protocol stack the dialog box for the module will be popped up For example to specify the physical layer parameters such as the channel ID operating frequency transmission power and the sensitivity for received signals one can double click the OFDMA_PMPBS_WIMAX module icon to invoke its dialog box which is shown as
74. protocol module to any desired place The user can also choose a module from a module group insert and place it in the middle working area In the node editor a chain of protocol modules represents the protocol stack used for an interface As such if a router has two interfaces it will have two module chains For example if a router has one interface that connects it to a host and has another interface that connects it to a switch it will have two protocol chains shown in its node editor The following figure shows the node editor for this router Node Editor To help a user distinguishes which module chain 1s for which interface the icon of the remote node that an interface connects to through a link is shown at the bottom of that interface As such in the figure a green switch icon and a grey host icon are placed at the bottoms of the two interfaces respectively If the remote nodes that a node connects to are all of the same type e g suppose that in the above example the router connects to two hosts showing the remote nodes icons at the bottom does not help distinguish interfaces In this case the user can position the mouse cursor over a remote node icon in the node editor The node ID of the selected remote node and the ID of the port on that remote node which 44 connects to this node will be shown at the bottom of the node editor This information can help the user distinguish inter faces when re
75. road network only Such a network model enables many new applications and research opportunities For example by exploiting road condition information shared among moving vehicles and road side units each vehicle can move at a proper speed and make turns more safely at intersections to avoid collisions with other vehicles The first step to conduct 139 an ITS network simulation is constructing a road network In this section we explain how to construct a road network in NCTUns The following figure shows the three kinds of road objects used to construct a road network which are listed from left to right as follows general road segment crossroad and road merger The three different kinds of road objects used to construct a road network in NCTUns The following figure is an example road network constructed using the provided road objects oo at AE 0 gaju yj aw g afa Suet I L428 _LSa 7 4 A oe amp a Sa Gr Seb r JH LLJ BeEEEBERESZr BER TSL PAE DERP AA Imp 1 om om An example road network constructed in the NCTUns GUI environment Load Road Map File NCTUns allows users to import a real world road map into the GUI program So far NCTUns supports road maps in the shape format To import a shape formatted road map one can perform the Load Road Map File Shape Format command which is at Menu gt G_Tools gt Load Road Map File Shape Format Because the shape formatted
76. s moving 123 Simulation Speed Real Time GUI GDR Debug Moving Path T Dynamic moving path generation 1 during simulation os Static moving path peneration before simulation Facket Transmission and Node Movement T Display packet transmission and node Le A movement during simulation Playback packet transmission and node 1 movement after simulation Cancel path is predetermined by the static path specified in the scenario description file sce file which is the default mode for non tactical MANET simulation cases The second important option is the mode of displaying packet transmission and node movement If this option is set as display packet transmission and node movement during simulation then the GUI program will run time display the packet transmission and node movement when the simulation is running The following figure is a snapshot of the GUI program when it displays the node movement at run time If this option is set as playback packet trans mission and node movement after simulation then the GUI program will not display any packet transmission and node movement during simulation Instead it replays the packet animation file ptr file after the simulation is finished AXAeoAa ean gee4uUNWEwO gs Jara iD nj ms Bann rrt a LLALLA SA 4i Far ehan BBE BRESP REA 44 2s A DER P 7 w iso Immo QQ ab ier The run time display of
77. simulating the behavior of a driver e g driving the car in line with the road direction keeping an appropriate distance between neighboring cars keeping the driving speed within a specified range making turning decisions at intersections etc If one wants simulated cars to behave in a different manner he she can replace the default car agent program with his her own One can find and modify the source codes of the default car agent program in the NCTUns package to suit his her needs The locations of the source codes are in the tools tacticMANET Ylib directory of the NCTUns package Car With Multi interface pplication Interface Start time s Stop timets Command Input file Name dd 0 000000 100 000000 CarAgent Modify Delete App Usage NCTUns does not allow a user to manually specify the moving path of an ITS car because if an ITS car specifies a Car Agent program to run on it the Car Agent program will control the moving of the car during simulation In case another moving path were also specified the two moving control mechanisms would interfere with each other resulting in unexpected simulation results For this reason NCTUns removes the movement specifying functions for an ITS car 150 Under the Interface tab one can add remove change the radio interfaces equipped on this ITS car The following figure shows an example interface setting for an ITS car
78. station and a mobile station through a relay station may get very little bandwidth and starve The following figure illustrates a typical example of IEEE 802 160 relay WiMAX network operating in the trans parent mode In this example network the TMR BS connects to the internet via a fixed link and forms an 802 160 transparent mode network together with other T RSs and T MS is G Setting N Setting Simulation View Help E Rel r oe ese Aey sweep Seeugs i ae LGA hA HALGA LG Se Bene eeees SD ERP 100 000 000 000 0 400 000 000 ooo FA a Node ID 2 The dotted red circles show the transmission ranges of the TMR BS and the T RS respectively As illustrated in the above figure both the T MS and T RS are within the trans mission range of the TMS BS The distance between the TMR BS and the T MS is purposely set so that it is very close to the transmission range of the TMR BS This arrangement makes the signal quality of the TMR BS sensed by the T MS very weak Gust a bit higher than the receive power threshold of the T MS Another way to make this condition is to place the T MS behind an obstacle so that there is no direct line of sight between the TMR BS and the T MS In this condition a traditional BS has two alternatives to transmit receive the packets to from the T MS One is that the TMR BS maintains its original modulation coding scheme used on the direct link between itself and the T MS However due to the decreased signa
79. switching optical network The following figure shows a network that is composed of a circuit switching optical network and a fixed Ethernet network Fes Ede Too i Tam G bery ji Say Sit Ye Ee Aro R EO SSA VUAY ww eee villa Fee iaWMILLAaLL ai SILLA LS ae E Bo i DER FP 4 BD Be BE EBESS BEY An example circuit switching optical network To protect a circuit switching optical network and enable it to recover from link or node outages various protection schemes can be used For example 1 1 unidirectional point to point link 1 1 bidirectional point to point link 1 N one protection link shared by N working links 2 fiber bidirec tional line switched ring 2F BLSR 4 fiber bidirectional line switched ring 4F BLSR etc NCTUns uses 2F BLSR to protect a circuit switching optical network In such a scheme a bidirectional ring is used to connect all optical switches The links on one unidirectional ring carries traffic and are called working links while the links on the other unidirectional ring serve as backup links and are called protection links If a working link breaks between two optical switches says the link from switch A to switch B the source switch of the broken link A will divert its traffic to a link on the protection ring The traffic will then travel on the protection ring and eventually arrives at the intended switch B The protection operation is automatically done at layer 2 and is transparent
80. that automatically move auto pilot on a constructed road NCTUns provides more realistic wireless physical modules that consider the used modulation scheme the used encoding decoding schemes the received power level the noise power level the fading effects and the derived BER Bit Error Rate for 802 11 a 802 11 b 802 11 p GPRS 802 16 d fixed WiMAX 802 16 e mobile WiMAX 802 160 relay WiMAX and DVB RCST satellite networks These advanced physical layer modules can generate more realistic results but at the cost of more CPU time required to finish a simulation Depending on the tradeoff of simulation speed vs result accuracy a user can choose whether to use the basic simple physical layer modules or the advanced physical layer modules NCTUns supports omnidirectional and steerable antennas with realistic antenna gain patterns The antenna gain data are stored in a table file and the content of the file can be changed even time varying easily if he she would like to use his her own antenna gain patterns Support for Various Network Protocols NCTUns simulates various protocols such as IEEE 802 3 CSMA CD MAC IEEE 802 11 a b e p CSMA CA MAC the learning bridge protocol used by switches the spanning tree protocol used by switches IP Mobile IP RIP OSPF UDP TCP HTTP FTP Telnet etc It simulates the DiffServ QoS protocol suite the optical light path setup protocol the RTP RTCP SDP protocol suite It simul
81. the Channel Encoding Decoding Option for the Transparent Mode WiMAX Relay Network v 802 16 j Subnet Management subnet Type Ds of Nodes In This 802 16 j Subnet ID Delete Subne 678 OK Cancel To enable disable the channel encoding decoding function one can turn on the Enable Channel Encoding Decoding flag As shown in the following figure the path of the flag is Menu gt N_Setting gt 802 16 j Network gt Transparent Mode gt Enable Channel Encoding Decoding By default the channel encoding decoding option is turned off by the GUI program W MICTUns 6 0 version EFUN oo File Edt G Tests H Tools G Salting H Seting Simulation View Help XA y A eiia Wireless ete FPR Lak AQREaRe a DE wf Seeese ae j eo GOR PSL et 0 POSS ee Bah BOS iibi Wines Hahk BOG iip Wirpiaa Hohe OVE ACS Saien hehwok Non trareparent Mode Sel GoS Provision tor Mobile Stations 0 Ot oo A HOTI A A db E pons EEF D 00 000 00 Oo Set QoS Provision For Transparent Mobile Stations The IEEE 802 160 network is QoS capable However the current IEEE 802 16 j network implementation in NCTUns only supports the best effort service Therefore the only QoS parameter required for each MS node s QoS provision is the maximum uplink sustained rate in Kbps As a rule of thumb the sum of the uplink bandwidth allocated to each MS should not exceed the maximum band
82. the NT MR BS thus there is no direct communication between the NT MR BS and NT MS To exchange packets between the NT MR BS and NT MS an NT RS should be used as an intermediate node to forward packets 164 N_ Tools G Setting N Setting Simulation View Help Utp QE lO MRoAZvyyvuwP g lA i eee ees Q2 D ERP 2 geass Reset Sanecig 5 a eee eS BS gs ORRON ar a Pi y Men E a Ar E T T ei nnn UUL 000 000 000 000 Node ID 3 Setting IEEE 802 16 j Non Transparent Mode Networks In the following we show how to use the GUI program to conduct an IEEE 802 160 non transparent mode network simulation case Insert IEEE 802 16 j Non transparent Mode Nodes To deploy an IEEE 802 16 non transparent mode network one can either insert IEEE 802 16 j non transparent mode nodes one at a time or place them in batch by using the automatic deployment tool As shown in the following figure the path of this tool is Menu gt N_Tools gt 802 16 j Network gt Non transparent Mode gt Insert 802 16 j Non transparent Mode Nodes By using this tool the nodes can be deployed in a random manner or in a grid manner Specify and Manage IEEE 802 16 j Non trans parent Mode Network Subnets To automatically and correctly generate the IP addresses for the IEEE 802 160 non transparent mode nodes the subnet relationship of these nodes should be explicitly specified using the
83. the home directory of the provided user account Hence this user account information must be correct and valid Otherwise the GUI program will crash due to access permission errors Specifying the email address is not mandatory However if this information is provided a remote dispatcher can send back a notification email to the user when the user s background job is finished in its simulation service center Currently this notification function is not implemented Since we have specified a complete simulation case and we are certain that the dispatcher and coordinator programs are running we can now proceed to run the simulation 3 Choose Menu gt File gt Operating Mode and select Run Simulation ES Applications Places System gs S i NCTUns 6 0 version 9 1 2009 Ele Edt G Tools N Toots G Setting N Seting Simulation View Heb New LCAL ELT ELET S eeugiia a GALI SIAL GAL SY Se Beh Bees DER P Save As Print to File Operating Mode Draw Topology Background Job Management Eda Property Ext CtreQ tun Simulation 0 000 000 O00 O00 Tr OOO 0 000 000 000 000 Select Node ID 2 3 E root locahost nc B root locahost usr i NCTUns 6 0 version 9 4 Choose Menu gt Simulation gt Run Executing this command will submit the current simulation job to one available simulation server or the only local simulation server managed by the dispatcher F3 Applications Places System io
84. the packet animation trace file Since the animation file is usually very large this process may take a while To give the user an idea of the progress a progress bar is shown during the loading process V nctunscl ient 0818 Loading root 6 0release Demo01_Twolnfra Demo01_Twolnfra results Demo01_Twolnfra ptr After the packet animation trace file is loaded the user can left click the start button J of the time bar located at the bottom The player will start playing back the logged packet transfer animation 47 AQ AJM I m pier Spe General Options for Packet Animation During the play of a packet animation trace a user can change some options of the GUI program to suit his her needs These options are described below Time Bar The time bar shows the packet animation progress in a time interval which is called a time window here A user can drag the time knot to any desired time Two buttons are provided to change the size of the time window by a factor of 10 That is the time window size can be either increased 10 times larger or decreased 10 times smaller A user can conve niently perform this job by left clicking the zoom out button Q or the zoom in Q button 200 000 000 000 000 000 000 000 Time bar and its knot Right below the time bar a red vertical line indicates that a wired packet transmission starts at this time a green vertical line indicates that a wireless LAN packe
85. the simulation machine If the external machine is a Linux machine the needed routing command should be as follows route add net 1 0 0 0 16 gw 10 0 0 1 Emulation Examples In the following we illustrate how to use external host external ad hoc mode mobile host external infrastructure mode mobile host and external router in emulations External Host External hosts can be connected to a simulated network in several ways In the following we present three emulation examples Example 1 The following figure shows the first example In this figure an external host is connected to the simulated network via a simulated link that sits between it and a simulated switch The external host wants to exchange TCP packets with the host in the simulated network Suppose that the IP address assigned to the simulated host is 1 0 1 1 and the IP address assigned to the external host in the simulated network is 1 0 2 1 First suppose that the external host wants to make a greedy TCP connection to the simulated host on the left In such a case the rtcp p 8000 command can be entered to the Application tab of the simulated host s dialog box Doing so will run up a TCP receiving program on the simulated host during the emulation After starting the emulation the GUI user can execute the stcp p 8000 1 0 1 1 command on the 57 oer BeOS ir tT FAIL LALL SIL ALSALA Sf Sa By ebb eh Ste be hy wm i LT fy ry ee ee ee ee
86. these wireless subnets he she can enter the IP addresses of all of these interfaces into this list The user then needs to specify the care of address used by this foreign agent Normally it is the IP address of the network interface that is used by this router and goes toward the correspondent host Note that since the mobile IP agent running on a router implements both a home and a foreign agents both the UDP port number used by the home agent and the care of address used by the foreign agent must be specified in this dialog box Finally if the user wants to use the Route Optimization scheme on this router this option needs to be checked Summary This chapter presents how to use Mobile IP in NCTUns In NCTUns Mobile IP is implemented as different agents daemons running on correspondent hosts mobile hosts and routers Mobile IP allows a mobile host to maintain its connections when it enters a subnet different from its home subnet 76 10 Physical Layer and Channel Model roles in realistic simulations of wireless networks P The tool Specify physical layer and channel model parameters is provided in NCTUns for users to specify the attributes of wireless physical layer modules and the parameters of wireless channel models This tool integrates all of the functions for setting the physical layer and channel model parameters into a unified user interface which includes the following components 1 antenna
87. to be presented later the address chosen must be the address that its coordinator program uses to register with the dispatcher It is the IP address of the network interface that is closest to the machine on which the dispatcher is running The Emulation Machine IP address field specifies the IP address of the above emulation machine If the emulation machine has multiple IP addresses 1 e it has multiple network interfaces participating in the distributed emulation See Example 3 to be presented later the address chosen must be the address of the network interface that connects to this real router Normally an emulation machine uses only one network interface to connect itself to a single virtual real router see Example 1 and 2 to be presented later In such a case the Coordinator IP address and the Emulation Machine IP address specified in this virtual router will be the same Finally the IP address of the real router s interface field specifies the IP address of the interface of the real router that corresponds to this port If the virtual router is used to represent a crossover cable or a layer 2 switch one should tick the Let multiple emulation machines communicate with each other directly option to enable the bottom panel On the this panel each entry in the table is composed of four fields Port ID Assigned IP address Coordinator IP address and Emulation machine IP address Their meanings
88. to each node Specify and Manage IEEE 802 16 d Mesh Subnets To save a user s time and effort the GUI program tries to automatically identify subnets and generate IP addresses for each layer 3 interface This can be done for fixed networks because nodes in such a network are connected However for wireless networks in which nodes are not connected the GUI program has no information to identify the subnet relationship and thus IP addresses cannot automatically be generated for wireless nodes In order to automatically generate IP addresses for the nodes in an IEEE 802 16 d mesh network one should first specify subnets before entering the Run Simulation mode To specify an IEEE 802 16 d mesh subnet one can first left click the form subnet button on the tool bar Next he she can left click multiple node icons in the working area to group together a set of nodes to form a subnet After selecting one or more subnet members 1 e network nodes the user can right click anywhere in the working area to terminate the form subnet action The following dialog box will then show up to ask the user if he she really wants to terminate this action The created subnets can be managed via the Subnet Management command which is located at Menu gt N_ Tools gt 802 16 d Network gt 802 16 d Subnets gt Manage 802 16 d Subnets After specifying subnets the IP
89. to this address format NCTUns allows a simulation case to have up to 254 subnets subnet ID O and 255 are excluded because they are used for broadcast purposes each of which can have up to 254 nodes hostNum 0 and 255 are excluded because they are used for broadcast purposes That is in total a maximum number of 254 254 64 516 layer 3 interfaces can be supported in a simulation case Although in theory NCTUns can support this large number of layer 3 interfaces in a simulation case in practice this is rarely done This is because each layer 3 interface needs to be simulated by a tunnel network interface but currently the installation script creates only 4 096 tunnel interfaces on a UNIX machine by default So precisely speaking currently NCTUns can support a simulation case using up to 4 096 layer 3 interfaces This also means that currently the maximum number of mobile nodes in a mobile ad hoc network simulation case cannot exceed 4 096 This is because each mobile node uses a layer 3 interface This 11 limitation can be easily raised to a larger number such as 8 192 by creating more tunnel interfaces on the simulation machine This change can be easily done by modifying the installation script The used subnet number starts from 1 and automatically grows upward The used host number on a subnet also starts from 1 and automatically grows upward If there are WLAN ad hoc mode mobile nodes in the network the subnet ID 1 is rese
90. to upper layers Therefore traffic flowing at the IP layer e g a TCP connection downloading a web page can continue its journey to its destination switch without disruptions The following figure shows how a 2F BLSR protection scheme works 108 Signal Entry Exit Point The 2 fiber bi directional line switched ring protection scheme On a circuit switching optical network a user can specify several 2F BLSRs to protect the network If protection is not needed a user need not specify any 2F BLSR To specify a 2F BLSR a user can use the optical protection ring tool button Al to sequentially select the switches that should be on the ring The sequence of the switches selected is important as it defines the direction clockwise or counter clockwise of the working ring of the 2F BLSR The operation used to select switches on the ring is like the operation for specifying the moving path of a mobile node A user first selects an optical switch by clicking on it Then he she moves the mouse cursor to another optical switch and clicks it to select it as the next optical switch on the ring The selected switch must be directly connected to the previous switch by an optical link Otherwise the protection scheme will not work properly If the user changes his her mind and wants to cancel this ring he she can right click the mouse at any place to discard the current ring During the ring creation process a thick red line
91. tool a user can use the mouse to select a rectangular region and zoom into it Selecting an area is done by clicking the mouse s left button hold it drag it to the diagonal corner of the area and then release it Normally after seeing the details of an area a user may want the zoom scale factor to return to the default value of 1 This operation can be done by using the Set the zoom scale factor to 1 tool button If a zoom scale factor other than 1 needs to be set a user can execute the Menu gt View gt Set Zoom Scale Factor command The following figure shows the dialog box of this function QP amp Bi Input the zoom scale factor between 0 0001 and 1000 1 00000 OK Cancel Form a Wireless Subnet The Form wireless subnet tool is a very important tool for setting up simulation cases of wireless networks Recall that to save the GUI user s time and effort the GUI program automatically identifies subnets and assigns IP and MAC addresses to layer 3 interfaces The GUI program performs this job very well on a wired network because all nodes including host switch hub router etc on such a network are connected and therefore all subnets on such a network can be identified However for a wireless network where mobile nodes are isolated nodes the GUI program does not have the intelligence to know which mobile nodes and IEEE 802 11 a b access points should belong to the same subnet W
92. tool to just move the head of the arrow Second the user can use the select tool to just move the tail of the arrow Third the user can move the entire arrow by clicking the mouse s left button on the middle of the arrow holding the button and then dragging the mouse To change the color and width of an arrow a user can use the select tool to double click any part of the arrow The following figure shows an example network where labels and arrows are added to make the network more readable ied So FS Te Yay Ebel JU wo PeeWee we ww Seo FBeBMrrrt Jj AL oO Bee REBHE SAE Pi Jeu gF e a 8 ARARA A Cisco 810 Router Linkl Link 1 Ce Geet wA A a gt I aoip E Poe 1 331 An example network in which labels and arrows are used The operation of the ruler is the same as creating a link between two device nodes A message box will show up displaying the distance in meter between the two selected nodes It is primarily used to place WLAN mobile nodes WLAN access points GPRS phones and base stations WiMAX subscriber stations and base stations etc at proper locations so that their wireless signals purposely can or cannot reach each other as planned Several zoom in or zoom out tool buttons are provided to allow the user to see the network topology in a suitable view The functions of some of these buttons are also provided as commands located in Menu gt View After choosing the Zoom in to an area
93. transmission range 29 e Mobile Node Ad hoc and Infrastructure mode Ww mobile station im im Dor n an ry A A H E f r SENFA 213 00 Add Modify Delete m Delete all Default moving speed to the next waypoint 10 00000 m sec Mat a ae Insert a sequence of random waypol Generate the last point of the whole path axcel0 goo Generate Import Export Import a sequence of points from file Export the current moving path to file PANS T M Show path Node editor OK A powerful and flexible configuration dialog box is provided for WLAN mobile nodes Under the Path tab the moving speed location X Y of each turning waypoint pause time during which a mobile node stays at the current waypoint can be configured To insert a waypoint into the middle of the existing path the user can first use the mouse to click the appropriate insertion point in the path dialog box and then click the Generate button In addition the moving speed between the new point and the next point will be automatically calculated so that the next point s arrival time need not be changed To generate a random waypoint path several methods are provided A user can ask the GUI program to generate random waypoints on the fly either one point at a time or ask it to keep generating waypoints until the arrival time of the last waypoint exceeds the specified time A user can also import a mobile node s path f
94. type in the command string will be tedious and take much time For this reason the GUI program automatically enters a default CarAgent command string into the Application tab of every deployed ITS car on behalf of users This command will launch the default car agent program for a simulated ITS car during simulation If the user wants to use another car agent 142 program with different driving behavior he she can replace the default car agent program with his her own one A user can find and modify the source code of the default car agent program in the NCTUns package to suit his her needs It is in the tools tacticMANET lib directory of the NCTUns package The default car agent program provided in the NCTUns package represents a proof of concept reference implemen tation showing that such a car agent program can drive a car on a road network with reasonable driving behavior The user can add more realistic driving behavior and intelligence to the default car agent program More information about the NCTUns capabilities on ITS researches can be referred to 1 2 IEEE 802 11 p OBU and RSU As introduced earlier the IEEE 802 11 p standard defines a whole new WAVE operation mode for vehicular networks Due to the great difference between the 802 11 p WAVE mode and the traditional 802 11 a b g networks the steps for setting up an 802 11 p network differ from those for setting up traditional 802 11 a
95. using the same protocol stack and parameter settings by executing just one command Each kind of wireless networks e g IEEE 802 11 a b WLAN IEEE 802 11 e WLAN IEEE 802 16 d e WIMAX GPRS DVB RCS satellite network etc provides its own command for this purpose and these commands are located in Menu gt N_ Tools The following figure shows the dialog box of this command for IEEE 802 11 b WLAN networks The added mobile nodes can be placed at random positions or in an M N array Their operating mode ad hoc or infrastructure can also be chosen The user can generate a large number of WLAN mobile nodes that use a protocol stack other than the default one To do so the user can first invoke the node editor in this dialog box to specify the protocol stack used by these mobile nodes If this operation is not done before adding a large number of nodes the user later may suffer from invoking all mobile nodes node editors to configure their protocol stacks individually Fortunately with the mobile node s C P A N S T function this tedious task can be easily and quickly done af aa amp Insert mobile stations Insert mobile nodes array Top left position xja Yi Dimension Insert mobile nodes at random positions Create mobile nodes Node editor Row Frotocol stack Column l 1 Node spacing 1200 meter Operating Mode Ad Hoc Mode Protocol stack Node editor In
96. various protocols It is out of the scope of this chapter to explain the details of GPRS Readers should reference some GPRS textbooks to understand the meanings of various GPRS parameters Reference 1 Y B Lin and I Chlamtac Wireless and Mobile Network Architectures John Wiley and Sons 2001 2 RJ Bud Bates GPRS General Packet Radio Service McGraw Hill 2002 101 13 DiffServ QoS Networks Q service DiffServ is one kind of QoS mechanism proposed to uality of service QoS is desired for users who request a better network service than the best effort service offered by the current Internet Differentiated provide differentiated services among different users This chapter illustrates how to use NCTUns to conduct DiffServ simulations DiffServ Concept Quality of service on networks can be provided by strictly guaranteeing a traffic stream s end to end performances such as bandwidth delay delay jitter packet loss rate etc or by differentiating traffic classes and giving them different QoS treatments The first approach IntServ may provide a better service than the second one DiffServ However the cost for offering the first service is much higher than the cost for offering the second service In DiffServ a simple and coarse method is used to provide differentiated classes of service for Internet traffic The DiffServ approach uses a small well defined set of building b
97. virtual router to pop up its dialog box In this example because a virtual router corresponds to a layer 2 switch one should enable the option Let multile emulation machines communicate with each other directly The detailed setting for the two virtual routers are shown below The first is for the virtual router on the left while the second is for the virtual router on the right Notice port 2 in the dialog box of the left virtual router and port 1 in the dialog box of the right virtual router Their Coordinator IP address fields should be set to 192 168 1 2 Their Emulation Machine IP address fields should be set to 192 168 1 2 and 192 168 2 1 respectively The reasons for these settings are the same as those for the Use two real routers to connect emulation machines mode which was explained previously After configuring the virtual routers one can switch the GUI to the Run Simulation mode and start the distributed emulation Virtual Router External Router ID 5 C Use a real router to connect multiple emulation n Port ID Assigned IP addrege Coordinator IP address Emulation Machine IP address used 192 168 1 1 192 168 1 2 192 168 1 1 192 168 1 2 Node editor Cancel Current Limitations Although the distributed emulation approach used by NCTUns provides many advantages it has several problems that remain to be solved One is that the order of the times tamp
98. yi TS Car With Multi interface pplication Interface 802 11 b mobile node lad hoe mode CPRe radii iE GPRS radio Modify DVB RCST Return Channel Satellite Termin Delete As shown in the following figure by clicking the Add button one can select which type of and how many radio interfaces to be added into this ITS car As introduced earlier NCTUns now supports eight different types of wireless mobile interfaces that can be added into an ITS car interface Z211 b infrastructure mode 211 b ad hoc mode interface P 11 p OBI DVB RCST Return Channel Satellite Termina _ 802 16 e mobile station One also can press the Modify button to set up the properties of a specific radio interface Before clicking the Modify button one has to choose one of the entries listed in the interface table to specify which interface he she intends to modify If one clicks the Modify button directly without specifying an interface entry by default the nctun sclient will invoke the dialog box of the first interface The following figure shows an example dialog box after one clicks the Modify button Name n Path Application Down time Interface Mobile IP Single hop coni lt 4 gt ID Xm 3 s Y m Arrival time s Pause tim dd Default moving speed to the next waypoint Insert a sequen
99. 02 3 MAC modules that are used inside a switch to ON no matter how the user set them The promiscuous mode is defaulted to OFF because the 802 3 MAC modules used inside hosts and routers need to filter out unwanted frames This ensures that frames can be forwarded by the switch without any problem Otherwise if the promiscuous mode is not turned ON frames will be discarded by the switch s 802 3 MAC modules Another task that the GUI program does for the user is to ensure that all interfaces that connect to a hub uses the hub s bandwidth as their interface bandwidth and the operating mode of the 802 3 MAC modules in these interfaces all be set to half duplex In the GUI program a user can indepen dently set different bandwidths for different interfaces and set an 802 3 MAC module s mode to either full duplex or half duplex without considering whether these interfaces are connected to a hub These wrong configurations surely will generate wrong simulation results and may even cause a simulation to crash This kind of wrong configuration bug is difficult to detect for a careless user As a result the GUI program does several underground tasks to save the user s debugging time and increase his her productivity Yet another task that is automatically done by the GUI program is that the GUI program will force the switch module used inside an access point LL or HEA to use the Run_Learning_ Bridge mode despite
100. 79 6 888 000000 594 000000 141 727142 0 000000 5804 000000 38 0 000000 pm Default moving speed an Cancel 148 Under the Interface tab one can add remove change the radio interfaces equipped on this multi interface node The following figure shows an example interface setting for a multi interface mobile node lulti interface Mobil Application Path Interface ID Interface type 802 11 b mobile node infrastructure mode 802 11 b mobile node ad hoc mode GPRS radio DVB RCST Return Channel Satellite Modi fy Delete Cancel As shown in the following figure by clicking the Add button one can select which type of and how many radio interfaces to be added into this multi interface node As introduced earlier NCTUns now supports eight different types of wireless mobile interfaces that can be added into a multi interface node mv Select the interfaces that this multi interface mobile node is to be equippe r interface list _ 80211 a infrastructure mode interface _ 802 11 a ad hoc mode interface Cancel _ 80211 b infrastructure mode interface _ 802 11 b ad hoc mode interface 80211 p OBI _ GPRS radio DVB RCST Return Channel Satellite Termina _ 8021 amp e mobile station One also can press the Modify button to set up the properties of a s
101. 99024478 60 300 2 87509070 180 19 98705548 62 298 2 60148357 64 296 2 30381027 66 294 1 97852366 The Gain Pattern of the 120 degree Directional Antenna Provided by NCTUns 68 292 1 62114483 70 290 1 22590750 Degree Gain dBi Degree Gain dBi 72 288 0 78521430 5 88539066 1 359 5 88472915 74 286 0 28877141 2 358 5 88274425 3 357 5 87943472 76 284 0 27785758 4 356 5 87479855 5 355 5 86883292 78 282 0 93582024 6 354 5 86153415 7 353 5 85289775 80 280 1 71790704 8 352 5 84291841 9 351 5 83158993 82 278 2 67905630 10 350 5 81890525 11 349 5 80485642 84 276 3 92226369 12 348 5 78943460 13 347 5 77262998 86 274 5 67876416 14 346 5 75443 184 15 345 5 73482844 88 272 8 68641770 16 344 5 71380703 17 343 5 69135381 90 270 156 24480078 18 342 5 66745391 19 34 5 64209131 92 268 23 68641770 20 340 5 61524882 21 339 5 58690803 94 266 20 67876416 22 338 5 55704926 23 337 5 52565148 96 264 18 92226369 5 49269228 5 45814777 24 336 25 335 98 262 17 67905630 26 334 5 42199253 27 333 5 38419950 100 260 16 71790704 28 332 5 34473993 29 331 5 30358324 84 Gain dBi Besides using example antenna gain patterns NCTUns 12 85512675 12 54414170 12 25889705 11 99621598 11 75352170 11 52869633 11 31997909 11 12589131 10 94518018 10 77677604 10 61975932 10 47333471 10 33681071 10 20958340 10 09112318
102. AC802 3 modules together To link together two modules a user performs the same operation as he she does when creating a link between two nodes in the topology editor At the top and bottom of a module there is a small box A link must start and end on these small boxes After linking up these modules the result is shown below M Node Editor QQ OQ VOPTICAL m ERS YPHY VYPSBM YRCST_CTL YDVB_RCS_GW lt gt MACB023 af of Step 5 Since the job is finished now we redraw the node editor to make it look beautiful The result is shown below WV Node Editor MAC8023 TCPDUMP Ei Se Select Mode t SS unao Recraws 7 A 45 7 A Step 6 If we would like to keep the changes made so far we can click the OK button On the other hand if we would like to discard all changes that we have made so far we can click the Cancel button Mi OK Cancel Set or View Module Parameter Values To set or view the values of a module s parameters a user can double click a module in the middle working area and then its module parameter dialog box will appear The following figure shows the parameter dialog box of the FIFO module a Module Edit D amp 2 OK Cancel Parameters Settina Max Queue Length pkts x Log Queue Ler Sampling Loq Rate 1 samples Full Log Log File Name P1 alen loa Run Time Query Current Queue Length Get Maximun Queue Len
103. AP MACBO23 MACBO23 80211 e I phy s 3 ra Select Mode The node editor of NCTUns Packet Animation Player By using the packet animation player a packet transfer trace logged during a simulation can be replayed at a specified speed Both wired and wireless networks are supported This capability is very useful because it helps a researcher visually see and debug the behavior of a network protocol It is very useful for educational purposes because students can see how a protocol behaves oo Te S OG isini weg emcee p phe A B s BEB SeReREMEV Se CLEATS EL i e BEBE rE SPR LLALLA LS LLSLLea ean arue BERBER Ber BENS AR aS Ese OER P ul J 108 u0 wm SS A 5 A Ehi iim a Pum The packet animation player of NCTUns Summary In this chapter we have briefly presented the features and capabilities of NCTUns After reading this chapter readers now should have a high level view about NCTUns 6 0 In the next chapter we will present how to install the NCTUns package To let readers quickly get a feel of the operations of this tool a short tour about running a simple simulation case will be presented in the next chapter Reference 1 S Y Wang and H T Kung A Simple Methodology for Constructing Extensible and High Fidelity TCP IP Network Simulator IEEE INFOCOM 99 March 21 25 1999 New York USA 2 S Y Wang and H T Kung A New Methodology for Easily Constructing Extensibl
104. Bar The tool bar contains many types of network device icons including host hub ga router GM switch Wa 802 11 b wireless LAN WLAN access point 802 11 b WLAN ad hoc mode mobile node b 802 Ea WLAN infrastructure mode mobile node bg 802 11 a wireless LAN WLAN access point L amp L 802 11 a WLAN ad hoc mode mobile node 2 802 11 a WLAN infra Structure mode mobile node ay multi interface mobile node having one 802 11 a WLAN ad hoc mode interface one 802 11 a WLAN infrastructure mode interface one 802 11 b WLAN ad hoc mode interface one 802 11 b WLAN infrastructure mode interface one 802 11 p OBU one GPRS radio one DVB RCST satellite interface and one 802 16 e mobile station YM obstacle can block attenuate wireless signal block mobile node s movement and block mobile node s view p Wide Area Network WAN abstraction host subnet and five emulation related types of network device icons external host a external WLAN ad hoc mode mobile node external WLAN infrastructure mode mobile node gj external router and virtual router As one sees the icons of most emulation related nodes contain an E which reminds that these nodes represent external real life nodes used in an emulation case The icon of the virtual router contains a V which indicates that it can represent a real router or be virtu alized by either a layer 2 switch or a direct Ethernet link More infor
105. D example l car_prof_cfg JexarnpleQl dvbres nodeid example 1 emu J exarmple01 gph Hho aJe Opn File name example01 8023_N2_P1_InOutThrput log File type All Files Cancel The example01 8023_N2_P1_InOutThrput log is a log file generated by the simulation engine and can be plotted by the Snapshot A user can execute this command to pop up the snapshot window for capturing the performance curve that is currently displayed in the window Snapshot Graph oO TOE Througniput O Ore le eee ese aa ela abe Save HM Cancel ERecsnaoshot In this window clicking Re snapshot button will re capture the performance curve that is being displayed Clicking Save button will save the snapshot as an image file of the bmp type Clicking Cancel will quit the window Snapshot All A user can execute this command to take snapshots of all existing graph windows The feature is very useful for comparing different performance metrics at the same time 52 Quit A user can execute this command to quit the current graph window PM Menu gt Window Add Remove Graph F Add Remove Graph This command provides a sub menu from which a user can choose different graph data source files Selected graph data source files are headed wi
106. D of this WBSS and the SCH that this WBSS uses A node should monitor all WSAs on CCH to know the existence and the operational information of available WBSSs After knowing the SCH of the WBSS that it wants to join a node may join this WBSS by periodically switching its channel to the SCH used by this WBSS on its service frames In the WAVE mode WBSS users need not perform the authentication and association procedures to join a WBSS Note these two procedures are necessary for a node to join an infrastructure BSS in the infrastructure mode of IEEE 802 11 a b g networks The reason is that in a high mobility environment such as a vehicular communication network wireless link connectivity among vehicles is very fragile In such a condition the chance for a high speed vehicle to join a WBSS fixed nomadic computer to join an infrastructure BSS With is much smaller than a this design a vehicle can quickly utilize the bandwidth of a WBSS after detecting its existence Because during the lifetime of aWBSS a WBSS provider may change the opera tional parameters of the WBSS a WBSS user should switch back to CCH in every transmission cycle to learn the latest information about its WBSS In the following we show the details of how to use NCTUns to construct an 802 11 p network from the scratch Road Network Construction In an ITS network vehicles are mobile nodes that have communication and networking capabilities and move on the
107. FIFO Random Early Detection Deficit Round Robin WAN are currently supported A user may add a new PSBM module such as a RIO module to it Detailed information on how to add a new protocol module to both the simulation engine and the node editor is documented in The Protocol Developer Manual for the NCTUns 6 0 Network Simulator and Emulator Screen Layout Explanation In the following we will briefly explain the screen layout of the node editor To see the node editor in the topology editor a user first switches the mode to the Edit Property mode by executing the Menu gt File gt Operating Mode gt Edit Property command Then the user can double click a node that he she wants to edit After the node s dialog box shows up the user can click the Node editor button to invoke the node editor to edit that node s protocol stack At the top of the node editor are various module groups The protocol modules that share the same role in a protocol stack are grouped together under the same group name When the user clicks one module group button all modules belonging to that module group will be shown right below the module 43 Node Editor Ao Select Mode The node editor s screen layout group buttons Because only four modules can be shown at the same time the user can use the lt lt and gt gt buttons to see other modules not shown on the screen In the middle working are
108. G_setting gt Dispatcher Now one can draw the network topology on the working area of the GUI After finishing drawing the topology one can switch the GUI to the Edit Property mode the E mode In the E mode one can set up the application programs that will be run during simulation For example we specify the stcp p 8000 1 0 2 1 command on the host 1 0 1 1 and the rtcp p 8000 command on the host 1 0 2 1 to run the stcp and rtcp programs on these two hosts during emulation One then double clicks the icon of the virtual router to pop up its dialog box In this dialog box one should tick the Let multiple emulation machines communicate with each other directly option to enable the bottom panel The detailed setting for this dialog are shown below Virtual Router External Router ID g C Use a real router to connect multiple emulation n Let multiple emulation machines communicate with each other di Port ID Assigned IP address Coordmator tP address TEMUatON Machine IP address used 192 168 1 1 192 168 1 1 192 168 1 2 192 168 1 2 Node editor Cancel After setting up the virtual router one can switch the GUI to the start the distributed emulation case Run Simulation mode and Example 2 In example 2 we use one virtual router to partition the network topology shown in the following figure into three parts The host 1 0 1 1 wants to establish a TCP conne
109. In the application tab a user can specify which application programs should be run up on this node program The following figure shows the content of this window For the first use the user needs to click the Refresh button to get the latest program usage information from the may be local or remote dispatcher A Apolicaton programs wear manuals Application Description rtcp A gimple rtpigendlreceive application for HLTUns developers 6 rtg it to suit their needs rt recvonl Usage rtpeendrecy Llocal_ip local_port LEMAHE Llocal_sdp L optiac stcp Llecal_ip t The IP address af the lacal Rast t lecal_ pert i The port number used by the application sig CHANE The CHAME used by the application the defin ttep is specified in RFCI550 SOP file ree the application the SO The SOP fil d by th peli i 0 specified im RFLedeS LlocalosdpJ lt eptions lt t tracefile Trace Hode Trace File Format Esch line in a trace file represents a packet that should be t In each line the first column indicates the length of the pac The second colunn indicates the idle time between tranemitting and the next packet Forna acketSizelin byte IntervalTimelin second hetresh DK The content of the program usage information window If a GUI user wants to install a new application program he she needs to copy _ that the usr local nctuns tools directory so that the simulation engine can succe
110. M GPRS base station Normally a base station is assigned the same number of frequency channels for its downlink and uplink traffic respectively That is if a base station is allocated 10 frequency channels it will have 10 channels in the uplink band and another 10 channels in the corresponding downlink band Using the TDMA scheme each channel is divided into time slots and 8 TDMA channels are formed by these time slots That is if we make 8 consecutive time slots as a group then the Nth time slot in every group are used for the Nth TDMA channel where N 1 2 8 A GSM user uses a download and uplink TDMA channels for his her voice traffic during the entire call period The time slots of these TDMA channels cannot be used by other users even though the user has no voice traffic to send A GPRS user normally is allocated 3 time slots and 1 time slot for his her downlink and uplink traffic respectively This service profile is typically called the 3 1 package The time slots allocated to a GPRS user can be dynamically used by other GSM or GPRS users when they are not used by the user Using the CS2 coding scheme in which one time slot corre sponds to 12 Kbps bandwidth a 3 1 GPRS user can receive 95 36 Kbps and 12 Kbps for the downlink and uplink directions the throughputs that may be achieved under ideal channel condi respectively These numbers represent optimal tions In reality the measured numbers are usually less t
111. NCTUns is used in its single machine mode During an emulation the GUI program simulation engine traffic generator application programs and some daemon programs all need to be run on the single machine Because they need to compete for the machine s CPU cycles the emulation precision may degrade However it has been found that if NCTUns is used in its multiple machine mode the precision is quite high and does not degrade When all external hosts are removed from the network topology purposely the GUI is designed not to automatically switch the speed option back to As fast as possible This is because even though there is no external host in a network topology sometimes it is still useful to let a simulation run at the speed of the real world clock For example when a GUI user wants to use the command console function during a simulation he she may want the simulation to run at the real world clock speed For the same reason even if a case is a simulation rather than an emulation the simulation speed option can still be set to As fast as the real world clock Insert External Host into a Network Topology First a user can click on the external host icon on the tool bar D and add it to the network topology Second he she then switches to the Edit Property mode and enters the IP address used by the external host in the real world This information must be known by the emulation kernel module otherwise it cannot
112. PRS Network gt GPRS Phone gt Insert GPRS Phones command can be executed The following figure shows the dialog box of this command V Insert GPRS Phones Insert GPRS phones at random positions Insert GPRS phones array Top left position X fso Y so Dimension Row GPRS phones Create Protocol stack Node editor Column ho Node spacing 200 meter Node editor coe Protocol stack If a user wants to create and insert multiple GPRS base stations into the working area in one step the Menu gt N_Tools gt GPRS Network gt GPRS BS gt Insert GPRS Base Stations command can be executed This command will create multiple base stations and place them in a hexagon form In the dialog box shown in the following figure the user can specify the top left position of the created base stations the number of base stations on the hexagon border and the horizontal spacing in meter between two neighboring base stations This figure shows a hexagon that has three base stations placed on each of its borders Fee Ge Q Toon jj Tam G Bette i fete Gee Fee Se Ae oT ea le a eee ae PE geese wii ae Tr PERRI LaALLaI_ aA TAALSe esa hee BeBe Str BEY ASRS Re Se DERP i at ea id Det s G lap m fa e eae iF Choosing an Outgoing GGSN A GPRS network can have multiple GGSNs connecting it to the fixed network Outgoing phone traffic with different NSAPI Net
113. R A light path that follows the directions of its underlying protection rings In contrast if the user specifies a light path in such a way that it runs in the different direction than its underlying protection rings although this light path can still work properly this arrangement is the most inefficient arrangement in that the light path s traffic needs to traverse the whole working ring to reach its next switch In the following figure although the light path is shorter than the light path in the previous figure and it seems that the light path s bandwidth usage is more efficient in fact this is not the case On the first ring its direction is clockwise in order to send traffic from 5th switch to Ist switch counter clockwise 5th switch needs to forward the traffic through 7th 6th 8th 4th switches on the clockwise working ring to let the traffic reach Ist switch The same problem also occurs on the third ring and the situation is even worse because to send traffic across a counter clockwise link the traffic needs to traverse the whole working ring and this penalty occurs twice on the third ring The second method to create a light path is to create it dynamically In this method when a packet needs to be forwarded from an optical edge router to another optical edge router and the light path between them has not been set up the optical modules in NCTUns simulation engine will find and set up a light path for them automatic
114. T SALLE ALS Sa eee BeSSSRBEC PERE AARAA a4 D ERP in e Bi Fi Tg Fi i a i ET aS a y yj COO DD DO os os ons ois vam oo AP mp External Router An external router can also interact with a simulated network This is a very useful feature as traffic originated from the simulated network can be directed to the router experience the router s packet scheduling and buffer management processing and then return back to the simulated network With this capability we can easily test the router s functionality e g sending virus and network attack packets to see whether the router can detect them The following figure shows an emulation example case where three simulated hosts are connected to an external router On top of this topology we set up two greedy TCP connections The first one starts at host 1 and ends at host 3 while the second one starts at host 2 and ends at host 3 The packets of these two TCP connections need to pass the external router That is they need to leave the simulated network host 1 and host 1 enter the real world network to reach the external router leave the router and then reenter into the simulated network host 3 The physical network setup for running this emulation is shown as follows The simulation machine needs to have three network interfaces each of which connects to one port of the external router Clearly three physical links are needed to connect these network interfac
115. TMR BS the mobile IP setting for a T MS can be configured by launching the Mobile IP tab in its dialog box The user should first tick the Enable Mobile IP option to enable the mobile IP function He she then fills in the Home Agent IP Address and My Own IP Address fields respectively The former refers to the IP address of the TMR BS in the same subnet as this T MS while the latter refers to the IP address of this T MS The functions of the Path and Application tabs are the same as those of an IEEE 802 11 b mobile node Thus we do not explain them to save space IEEE 802 16 j MR BS in Transparent Mode Node ID Mobile IP Tl Enable Mobile IP l Enable Route Optimization RO This agent implements both the home agent and the foreign agent Administered MN s IP Address Wireless Interface IP Address l _ Add Delete Care of address Port l V IEEE 802 16 j MS in Transparent Mode Node 3 Name IMs Path Application Mobile IP ommand console l Enable Mobile IP Home Agent IP Address My own IP Address C P AN S T Node editor M Show path IEEE 802 16 j Network Protocol Stack The settings of IEEE 802 16 related protocol modules can be specified via the Node Editor The following figure shows the default protocol stack of an 802 160 TMR BS node 163 Select Mode By double clicking t
116. The GUI User Manual for the NCTUns 6 0 Network Simulator and Emulator NC TUns 6 0 gt gt et D a D D D lt 2 F 0 O E O ce m oO C Q C 4 lt M p af rt a w 5 BOUSINS JaINdWwosd Jo zju awypedaq Aloyesoqe WajshS pue YIOMISN OLOZ 0007 WwHUAdoD Authors Prof Shie Yuan Wang Chih Liang Chou and Chih Che Lin Last update date January 15 2010 Produced and maintained by Network and System Laboratory Department of Computer Science National Chiao Tung University Taiwan Table of Contents ke ie aoye lela ee omer ene teen ie eee a eee ad ete ten Oe eae ene nee nor ee renee eT eter l UREE EEA AE S N E E I TENE IA catia E EA 7 Ded OPOlO Py EIO eenaa A O O 19 A OE E LL ON E PE EN E I O A AE E OP EET AAO 43 PI EKTA O AYO E r AE O EEA EA EA ATTE 47 60 Perrormance MONIO ssicetcnsictaceacasadedsdeGadatenewadadtietevenisateebee eaespelsaiuasdiaderundiedtianetensieses 51 PE PU L EO i EE ATE TATEN T EAT EEE E E EAEE A NEIE EAT en 55 o DISt1 Ute Emula ON eeren aE A A asapehseateedeemiatie 63 9 MODE IPE ays AET A EEEE TEEN EEEE EN RENTE 74 LO Physical Layer and Channel Mode siscasssnsuntentuaiuaatainteitact a ERR T1 lURTP RTCEP S DPE eerie E E T EEE EENE EEEE 90 IZ OPR S NEW O KS oea AEE TEO E E AEAT E des teen IOTA TNR 95 ODPISE OOS NEtWOrK S aroase a A a E a 102 1A Opucal NEIWOTK Siiran eienen E E 107 15 IEEE 802 11 Wireless Mesh Networks cece ce
117. Topology to Edit Property and then double click the NCC node In the following popped up dialog box one has to choose the tab of Forward link arrangement On this tab one can set the values of the central frequency for the forward downlink and uplink channels Rete link arrangement Groping Retum ink eapacky Retum lnk frequency Forward link arrangennent Central frequency of ihe whole forward uplink channel band oa GHz Central requests of the whole oraa downin channel tint 25 GHI Unlike the forward link multiple channels are allowed to be used on the return link The following figure shows the return link channel assignment uplink frequency band Frequency central frequency central frequency downlink frequency band l Return link channel assignment For the return link one has to assign the central frequencies for the whole uplink and downlink frequency bands In addition one has to specify the bandwidth of each channel so that the central frequency of each channel can be derived automatically by the GUI program The bandwidth of each channel is the same in the current implementation The value 127 of the central frequency of each channel will be used to calculate the BER Bit Error Rate on the uplink downlink when a simulation is running The channel ID e g chO ch1 ch2 etc is automatically designated by the GUI program To set the central frequency and the channel bandwidth one ne
118. Traffic Appli cations command does the reverse job It removes the appli cation command strings of all nodes from their respective Applications tabs These two commands are useful for large network cases because they can save much time and effort for a user The following figure shows where these two commands are located oe wp bb eee se Be ae oh Pin named amirinin oem a LOLLY sabe we ba ds Suni pana EK D ERP Settings for WLAN Mobile Nodes Several display flags are provided for WLAN mobile nodes in Menu gt N_ Setting gt 802 11 b Wireless Network Show Moving Path This command can change a flag to display or not to display the moving paths of WLAN mobile nodes Show Icon This command can change a flag to display or not to display the mobile node icons It is useful when the user just wants to see mobile nodes current locations represented by boxes with solid and thick edges and does not want them to be messed up with their initial locations represented by mobile node icons Not showing the initial locations of mobile nodes in the working area can make the current network topology clearer Show ID This command can change a flag to display or not to display the IDs of mobile nodes Like other display flags in a large simulation case not showing the IDs of mobile nodes may make the current network topology clearer Settings for Optical Networks The following commands can be executed to change the
119. Using an ITS Intelligent Transportation System case as an example now the user can import mobile nodes and their moving paths from a file In this ITS case each mobile node represents a mobile car and its moving path represents how it moves on the roads This command is located in Menu gt G_Tools Import Network Traffic Application File Suppose that we would like to run some application programs on these imported mobile cars to exchange infor mation among them we can use this command to import application program command strings from a tfc file The details of this command have been explained before Executing this command can save the user a lot of time because he she need not invoke the GUI dialog box of every mobile car to specify their application programs This command is located in Menu gt G_ Tools Obstacles In the real world not all fields are open space for wireless signal Some may have high mountains or tall buildings blocking wireless signal s propagation or attenuating their power In some researches we may want to purposely add obstacles to the open field to block attenuate wireless signal at some places in the field In NCTUns an obstacle isa rectangle that can block a mobile node s view block a mobile node s movement or completely block wireless signal or just attenuate the power of wireless signal These properties are important for simulating tactical mobile ad hoc networks An obstacle can be ad
120. WiMAX networks The network device icons for IEEE 802 16 e WiMAX networks include 802 16 e Base Station BS in PMP mode a _ 802 16 e Mobile Station MS in PMP mode ej The functions of these devices will be explained in a later chapter for IEEE 802 16 e WIMAX networks The network device icons for IEEE 802 160 WIMAX networks are classified into two groups The first group is for the transparent mode including 802 160 MR_BS in trans parent mode 7 802 16 j fixed RS in transparent mode 1 and 802 16 MS in transparent mode a The second group is for the non transparent mode including 802 160 MR_BS in non transparent mode 1 802 16 fixed RS in non transparent mode rY and 802 16 j MS in non trans parent mode Je The functions of these devices will be explained in a later chapter for IEEE 802 16 j relay WiMAX networks 20 The network device icons for DVB RCST satellite networks include DVB RCST service provider 5 DVB RCST Network Control Center NCC lt 0 DVB RCST Return Channel Satellite Terminal RCST 7 DVB RCST feeder gt DVB RCST traffic gateway 36 DVB RCST satellite and DVB RCST pseudo switch The functions of these devices will be explained in a later chapter for DVB RCST satellite networks The icons for wireless vehicular networks in Intelligent Transportation Systems are divided into two groups The first group is for constructing a road network and includes ITS road segment ITS c
121. a the protocol modules used by this node are shown Here a chain of protocol modules represent the protocol stack used by a port interface The user can use the mouse to easily add delete or replace protocol modules in the working area At the bottom are several control buttons The Cancel button discards all changes that have been made to this node s protocol modules The OK button accepts all of the changes made so far The Undo button removes the effect of the last delete operation Note only the LAST delete operation can be undone The Redraw button re layouts the protocol modules so that they look nice when shown on the screen This is particular useful after a user performs the insert or delete operation The Copy To All Port CTAP button copies the values of the currently selected module s parameters to the same modules in all ports of this node The Copy To All Node CTAN button does the similar job However it copies the values to the same modules in all ports of all nodes in the whole simulated network The X button means delete After clicking this button now the node editor s mode enters the delete mode From now on whenever the user uses the mouse to left click a module or a link that object will be deleted The Arrow button means select After clicking this button now the node editor s mode enters the select mode From now on the user can move a
122. a RCST node one can pop up the node editor of the RCST node first After double clicking the DVB_RCS_RCST module box one will see a popped up dialog box like what is shown below On the left hand side of this box one can set up the antenna related parameters such as Tx power ground station antenna length and ground station antenna efficiency On the right hand side of this box one can set up the rain fade parameters One can either set the desired rain fade directly or set the relative parameters such as antenna angle polarization rain height earth station height latitude and rain rate which are used to calculate the rain fade 136 V Module Edit OA RCST Parameters Setting re Power Ground Station Antenna Length 13 im Rainfade OK Default Sarees Cancel Rain Fade 20 Ground Station Antenna Efficiency 0 68 User Defined x Link Failure Antenna Angle 89 degree See Down Time Setting Polarization 0 degree File Name s Dvb_rcs_rcst_N7_PLlinkfail 0 for horizontal polarization 45 for circular polarization 90 for vertical polarization Rain Height 3 1 km Earth Station Height 0 07 km Latitude 24 degree Rain Rate 50 ram h To configure the receiving sending point at the Satellite node one can pop up the node editor of the Satellite node first After double clicking the DVBS2_SAT module box one will see a dialog box like what is s
123. a power threshold that the chosen node should set if it wants to sense the transmission activity of the node X Similarly the latter denotes under the current antenna and channel model setting the minimum value of the antenna power threshold that the chosen node should set if it wants to correctly receive packets transmitted by node X After setting the DIR and DTR values one can click Recal culate button to ask the GUI program to compute the CCSPT and CRPT values The obtained CCSPT and CRPT values will be shown in the text fields of the bottom column One can manually modify these two values to meet his her own needs by clicking the Modify button However one should notice that each time when the Recalculate button is pressed the two values stored in the text fields will be automatically replaced by those derived from current antenna and channel model setting w tify physical layer and chine aak parierters Propagebor hand Migi Theoretical Oren Mewiel Path Logs Poza Fadia Mickel Emona hamal Figi ode Lonrecinaty Display Ue the transmitting node perepectine E le the roig made perspectie Pode Lonrecinaty Detimi Debermined by power thireshoad Determined by itane ARADA Geen Patten and Danectnety Forantennadeight rm 15 D T R of a neighboring mode im EPA N S T PAM CLA of a n ighbonng node nm i oe Gace Antenna Parameter Setting On the top left of the dialog box is the ant
124. ach RCST has to be assigned into a group and each group is assigned a unique group ID The RCSTs belonging to the same group use the same channel for transmission on the return link Each channel is assigned an unique channel superframe ID Multiple groups of RCSTs can share the transmission capacity of the same channel In other words the relationship between group IDs and superframe IDs can be a many to one mapping To specify the mapping one has to double click the NCC node In the popped up dialog box shown below one has to choose the tab of Grouping On the right hand side of the tab two buttons are provided for group ID assignment and Group ID to Superframe ID mapping Cancel Before clicking the Specify Group ID button one has to first choose a RCST whose group ID is to be specified The following figure shows the popped up dialog box after one clicks the Specify Group ID button The group ID of the selected RCST can be set in this dialog box Group ID D e era Enter Group ID a 3 mom Cancel Before clicking the Map Group ID to Superframe ID button one has to first choose one RCST whose group ID is to be mapped to a superframe ID The following figure shows the popped up dialog box after one clicks the Map Group ID to Superframe ID button The group ID of the selected RCST is displayed only for reference and cannot be modified One then chooses the desired superframe channel ID tha
125. acket trace file represents a packet that should be transmitted and has two columns The first column is the packet size in byte while the second column is the Interval time in second between this packet and the next packet Host3 s RTP dialog box as SDP Information Email address bobo nctu edutw should Phone number should Session bandwidth Session active time from 0 PCMU 8000 8 audio Media type audio ig Destination port number 5004 Ls Payload type 03 Encoding name Sampling rate HZ 8000 Bits per sample 8 Audio packet time ms Video frame rate F sec Please reference RFC 3551 for explanations of these parameters Host3 s SDP dialog box Cancel OK aD Q be sent every l RTCP packets al v be sent every RTCP packets 1600 kbps secto 200 sec Destination IP addressles IP address Add Delete Save Cancel 94 Summary This chapter presents how to use RTP RTCP and SDP in NCTUns In the NCTUns RTP and RTCP are implemented as a user level library whose API functions can be directly called by a user level application program NCTUns provides three RTP example programs that use the provided RTP library A user can study their source code to learn how to use the RTP library to make his her own RTP application programs Reference 1 RFC 1889 RTP
126. addresses of mesh network nodes can be automatically generated and assigned by the GUI program However to correctly generate routing paths for these nodes one should further specify gateways for the formed subnets To do so one can left click the Specify 153 eRe see yveua ps Jeug a4 Lid 8 L48444 aq aga a Xe EDRR rrr wh Lis Be B BRE BEY cie e a DERP 0 10 10 on on AQ ir ilar The subnet formation dialog box shows the IDs of the selected nodes to form a subnet Gateway button in the dialog box of the subnet management command In the Specify Gateway for a Subnet dialog box one can add a gateway entry modify it or delete it A gateway entry is made up of three fields the source subnet the destination subnet and the ID of the gateway node used by the source subnet for routing packets to the destination subnet Source Suboet Destination Subnet Gateway ID Specify Maximum Transmission Range For IEEE 802 16 d Mesh Nodes One can specify the maximum transmission range for IEEE 802 16 d mesh nodes via Menu gt N_ Setting gt 802 16 d Network gt Set Maximum Transmission Range For 02 16 d Stations command Then the maximum trans mission range for each type of nodes can be specified in the following dialog box B0216 d Ps Mode BS S02 16d Ps Mode Gateway SS S02 15id PMP Mode Host SS h Mode BS a i SU Ted Mes S02 16d M
127. ally Therefore if light paths are not the focus of the simulation a user need not manually configure the light paths between every pair of optical edge routers 110 BAr 48 SECHARSASCEEVS GPSPSBsAiaegiies I EES TTS BH ALEGALSE LO 1191718 CSE SBULS BSERRORaSr nar AARAa amp SRA SS SIDER P a aft re OO D N oe oe A light path whose direction is against the directions of its under lying protection rings After a user has created several protection rings and light paths he she may want to delete some of them or see how they traverse on the optical network To do this operation a user can execute the Menu gt N_ Tools gt Optical network gt Manage Optical Network Protection Rings and Edge Router to Edge Router Routing Paths command The following figure shows the dialog box of this command In this dialog box to delete a protection ring or a light path a user needs to select it first This operation can be done by clicking the ID of the ring or the light path BAe B G48 eB EeCeSeabwveye SSSR It BePiie2e Bat TTS SH LLALLA LG 1749147458 E SEBSBLE SEREOCR BSE naar ie A Sety Sete Yer noy AR amp ARSR ee DER P P 4 of 0 00 00 on on ia veo one oo oe A dD l a a ar Seer tetas 4 r Configured protection rings and light paths can be managed in this dialog box After these settings the user can specify the application programs to be run up on hosts e g stcp a
128. ans mission range of the middle mobile host At this time it can no longer communicate with the simulated mobile host on the right via the middle mobile host N Tocs G Sein H Setting Sirwistion View tiep Fie Edi Q Tous XAeorVFA EB wo RRSoReuyvvuusg GSvSuT inen j o A l rr FHILLGALSINS GD ALSALS Sa Beye BSeSbSetter BBA ASARRARSS DERP e ub ab The physical setup for this emulation case is one simulation machine and one external mobile host need not be mobile The external mobile host can use either a normal Ethernet link to connect to the simulation machine or an IEEE 59 802 11 b wireless interface Actually it does not matter which type of network link is used between the simulation machine and the external mobile host as long as their IP packets can be exchanged on the used network media As in the external host emulation case the simulation machine and the external mobile host should be on the same subnet Let s assume that the simulation machine s IP address is 10 0 0 1 and the external machine s IP address is 10 0 0 2 and they are physically connected via a Fast Ethernet crossover cable Then on the external mobile host the user should first execute the following command to add the required routing entry to its system routing table route add 1 0 16 10 0 0 1 on FreeBSD route add net 1 0 0 0 16 gw 10 0 0 1 on Linux Also if a node either a simulated node or an external mobile node wants to send packe
129. ansparent mode a Using the default value 0 means that the seed Random Number Seed i will be automatically generated A force member in a battlefield can be modeled and simulated by a mobile node in a tactical mobile ad hoc network Each mobile node needs to specify an agent program to be run on it One can open the mobile node s dialog box and then specify such an agent program under the Application tab Obstacle An obstacle is an essential component used to model a real battlefield In NCTUns 6 0 an obstacle has four important attributes which can be set by double clicking an obstacle The default values for these attributes can be set by executing the Menu gt G_Setting gt Obstacle command The first attribute is the width of this obstacle The second one is the block node view property namely whether an obstacle blocks the view of nodes or not If this property is enabled the obstacle should block the line of sight of network nodes during the simulation The third one is the block node movement property If this property is enabled the obstacle should block the movements of mobile nodes The final one is the block wireless signal property If this property is enabled the obstacle will block a passing wireless signal or attenuate its strength by the amount specified The following figure shows the dialog box of an obstacle in the NCTUns GUI program wr Obstacle Properties nod
130. ates the IEEE 802 16 d e G WiMAX PMP protocol suites and the 802 16 d mesh mode protocol suite It simulates the DVB RCST protocol suite Highly Integrated and Professional GUI Environment NCTUns provides a highly integrated and professional GUI environment in which a user can easily conduct network simulations The NCTUns GUI program is capable of e Drawing network topologies e Configuring the protocol modules used inside a node e Configuring the parameter values used inside a protocol module e Specifying the initial locations and moving paths of mobile nodes e Plotting network performance graphs e Playing back the animation of a logged packet transfer trace e Pasting a map graph on the background of the network topology e Constructing a road network for wireless vehicular network simulations e More Popular Operating System Support NCTUns runs on Linux operating systems The Linux distri bution that NCTUns 6 0 currently supports is Red Hat Fedora 11 whose Linux kernel version currently is 2 6 28 9 Other Linux distributions such as Debian can also be supported with some minor operating system configuration changes Open System Architecture By using a set of well defined module APIs that are provided by the simulation engine a protocol module developer can easily implement his her own protocol and integrate it into the simulation engine Details about adding a new protocol module to the simulation eng
131. atically propagated to and set in the physical layer module e g PHY of node A Therefore the down time periods set in an interface s physical layer module actually is the union of the down time periods of the node to which this interface attaches and the down time periods of the link to which this interface connects In addition to the down time information other attributes of a link are also automatically propagated to the appropriate modules of the two nodes that connect to this link For example the bandwidth signal propagation delay and BER are all propagated to and set in the corresponding physical layer modules Note that this automatic link parameter propagation process will override the settings specified by the user in the node editor for these physical layer modules The GUI program adopts this design because it is more intuitive to set a link s attributes by double clicking it 26 Individually invoking the node editors of the two nodes that connect to a link to set their link attributes is less intuitive and may result in inconsistent settings Command console button is provided in the dialog boxes of several nodes This function is enabled only when a simulation is running A user can use this console to log into the current node the node whose dialog box is shown right now A xterm terminal window will appear In this terminal window a user can run the tcpdump program to capture packets passing through one of t
132. ation The first difference is that a GPRS phone MS in NCTUns has a TCP UDP protocol layer in its protocol stack while a GPRS phone in the real world does not have one In NCTUns because internally a GPRS phone plays the same role as a host the TCP UDP and IP layers of a GPRS phone s protocol stack are the simulation machine s real world TCP UDP IP implementation Also any real world appli cation program can run on a GPRS phone just like being run on a host These capabilities are beyond the capabilities of current GPRS phones in the real world and may only be possible on 3G or 4G phones The second difference is that in NCTUns a pseudo device named GPRS switch must be used to connect a SGSN with a GGSN while in the real world it is unnecessary This design decision is based on the fact that multiple GPRS tunnels may exist between multiple SGSNs and multiple GGSNs To let the IP addresses of the endpoints of these GPRS tunnels share the same subnet ID for easy management NCTUns GUI enforces that a GPRS switch must be used to connect a SGSN with a GGSN even if only a pair of SGSN and GGSN exists in the simulated GPRS network Note that the GPRS switch is just a device used in the GUI to enforce such a connectivity Actually it does not exist in the exported tcl file That is there is no such a device in a GPRS simulation execution Instead the packets of a GRPS tunnel 96 UDP TCP UDP T cp ol aaa SGSN GGSN
133. ault values of these parameters e g the Channel ID parameter based on the simulated network topology Module Edit Parameters Setting Channel 1D Frequency MHz 2300 Cancel Transmission Power dbm 2 Receive Sensitivity dpm 99 According to the 802 16 j standard the NT MR BS and NT RSs in the same cell can use different frequencies to transmit receive control messages and data However the current implementation of NCTUns only allows all non transparent stations in the same cell to use the same channel for communications For this reason one must ensure that the channels used by the NT RSs and NT MSs are set to that used by the NT MR BS This basic implementation has a drawback on network performances As shown in the following figure if a NT MS is located within the signal coverage of a NT MR BS and those of several NT RSs the red dash lines indicate that the NT MS can sense signals from both the NT MR BS and the NT RS the NT MS may not be able to receive any control messages and data transmitted from these nodes The reason is that because in an 802 16 j non transparent mode network both NT MR BSs and NT RSs should transmit their own control messages The 802 16 j standard does not specify a mechanism to coordinate these message and data transmissions on the time axis Thus the message and data transmissions of NT MR BSs and NT RSs may overlap with each other on the time axis In this condition cont
134. begin to be exchanged via the simulated network That is their TCP packets will traverse the simulated link switch and router Example 3 The following figure shows the third example which is intended to show that an emulation topology can be very simple In this figure two external hosts are connected to the simulated network and the simulated network is just a link The left external host connects itself to the left end of the link while the right one connects itself to the right end of the link The two external hosts want to exchange their TCP packets via the simulated link Assume that the IP address assigned to the left external host is 1 0 1 1 and the IP address assigned to the right external host is 1 0 1 2 a Eat 5 Ton ar a G Farg li brna im jas Hep tX re ypa ngaj yitu g rya ja AI l EEEN ATT E E Ae Er behe BeSESSSEE BER AARRR eS DERP Suppose that the left external host wants to make a greedy TCP connection to the right external host In such a case the rtcp p 8000 command should be first run up on the right external host Then the GUI user can start running the emulation The GUI user can then execute the stcp p 8000 1 0 1 2 command on the left external host to run up the TCP sending program If the two external hosts are physically connected to the simulation machine and their routing configurations have been properly set their TCP packets will begin to be exchanged via the simulated network To pur
135. c Application File For a large network that has hundreds or thousands of nodes double clicking the icon of each of these nodes to enter the application command string for the node is a tedious and time consuming job To avoid wasting time and effort on doing this job the user can use the Menu gt G_Tools gt Import Network Traffic Application File command to read in a traffic configuration file tfc The format of a tfc file is exactly the same as the tfc file exported by the GUI program for a simulation case when it switches its mode to Run Simulation Therefore to understand the format of a tfc file the user can first make a simple case and then export the case s tfc file Each line in the tfc file specifies the node ID starting time ending time and application command string for a node The format of a line is node_ nodeID start_time end_time application_command_string Normally a tfc file imported by the Import Network Traffic Application File command is generated by a script or a program written by the user Each traffic generator 1 e application program command string specified in the tfc file will be put into the Applications tab of the specified node This facility can save a user a lot time because now the user need not invoke each node s dialog box individually to enter its used application command strings Remove All Network Traffic Application The Menu gt G_Tools gt Remove Network
136. c is sparse J pauses the animation W stops the animation h moves the animation time window by one time window size in the backward direction moves the animation time window by one time window size in the forward direction 40 ps H 100 z The 40fps frames per sec selection box controls the display quality of the animation It defines how many frames should be played in a second in the real time Using a smaller value can increase the animation speed because fewer CPU cycles are needed to refresh the screen However the resulting animation may become rigid and not smooth The 100 selection box controls the progress of the animation It affects the time advancement quantity of the playback clock During playback the playback clock is advanced by a fixed time quantum in each of the playback loop After the playback clock is advanced all of the packet transfers whose transmission period 1 e the period between the transmitting and receiving times covers the current playback clock time are selected to be displayed on the screen Choosing a larger value for this parameter will advance the progress of the animation playback more quickly However more packet transfers will be skipped and not displayed in the animation playback Therefore if packet transmission times over the links in a simulated network are tiny e g tiny 58 byte TCP ACK packets transmitted on a 10 Mbps link or 1500 byte TCP data packets tran
137. can be seen one can specify 1 the type and the number of the inserted nodes 2 the positions where the nodes will be placed and 3 the protocol specific settings that are to be applied to each node m Insert 802 16 d PMP nodes at random positions 7 Insert 80216e PMP nodes array Top left position t random positions co a X 180 Y 180 Dimension Row j 80216e MS Node Specify and Manage IEEE 802 16 e PMP Subnets Like in the IEEE 802 16 d mesh network the GUI user must use the form subnet tool to group a PMP BS node and a number of PMP SS nodes together to form a subnet Doing so allows the GUI program to automatically generate IP addresses of these nodes saving the user much time and effort The created subnets can be managed via the Subnet Management command which is located at Menu gt N_Tools gt 802 16 e Network gt 802 16 e Subnets gt Manage 802 16 e Subnets Set QoS Provision For Mobile Stations The IEEE 802 16 e network is QoS aware As such before starting simulation one ought to specify the QoS provision setting for each simulated MS node using the Set Qos Provision for Mobile Stations command The path of this command is shown as follows Menu gt N_Setting gt 802 16 e Network gt Set Qos Provision for Mobile Stations H Etm a eran W L ro i L Vevuag Peeves jae ji XA eo AUS
138. ce eeeccseccescccsccesceusccesscesscesscesscessees 115 1G TEBE 302 116 OOS NetWO K S weer tisttiunataro ene eaenaie 118 17 Tactical and Active Mobile Ad Hoc Networks ccc cece ceccseccesccsccsscescescesscuscens 121 18 DVB RCS Satellite Networks oo cccccecceeccssccsccesceesceeccesscescescenseescescesseuseees 125 19 TREE 30211 1609 INGUW OI Sereia eee nese aise a ees 138 20 Miu ltisinteri ace Mobile INOGCS sicsosensi foucenicaeadenaebatwosctanwabotacacebalanandudimadiea Mcdeacetselasesiead 147 21 IEEE 802 16 d WIMAX Networks sosiescnssedsncsicnssoccsusiionseds secedenwbietsaedisedatenevidsdsadesesys 152 22 IEEE 802 16 e WIMAX Networks s senssnssensssnssenssessesssesserseesssrsserssessersersseessesseee 156 Zo IEEE S302160 WIMAX NetWork Serres duadvewnkiabiah eralhadiateidaweneme 160 1 Introduction elcome to the GUI user manual of NCTUns a high fidelity and extensible network simulator and emulator In this introduction we will briefly introduce the capabilities and features of NCTUns To help users understand how NCTUns works the high level structure of NCTUns will be presented in detail Some screenshots are shown in this chapter to let readers get a feel of NCTUns Capabilities and Features NCTUns uses a novel kernel reentering simulation method ology 1 2 3 4 5 6 7 8 As a result it provides several unique advantages that cannot be easily achieved by tradi tional network simulators In the fol
139. ce of random waypoints until the exceeds last point of the whole path Import a sequence of points from file Export the current moving path to file Show path Exploiting Multiple Heterogeneous Wireless Inter faces As shown in the following figure application programs running on a multi interface mobile node ITS car can utilize multiple wireless interfaces to transmit receive packets To utilize such heterogeneous interfaces the appli cation programs should know the IP addresses assigned to these underlying interfaces One should explicitly provide such information for application programs using command line arguments This is because so far no system calls are provided for application programs to obtain such infor mation User Space Kernel Space 1 0 2 1 IEEE 802 11 b infrastructure mode 1 0 3 1 IEEE 802 11 b ad hoc mode 1 0 1 1 GPRS 1 0 4 1 Satellite 151 Given the IP addresses assigned to these interfaces an appli cation program can first create sockets for these interfaces and then call the bind system call to bind each of these sockets to each of these IP addresses After performing these binding operations the application program can send out packets through any desired interface by writing these packets into the corresponding socket Similarly the appli cation program can receive packets from any desired interface by reading pac
140. cket length In fact a packet s segment length on a particular link is determined by the transmission time of that packet on that link relative to the signal propagation delay of the link Wireless LAN Network Similarly in the following two screen shots are presented to illustrate and explain the wireless animation effects Ebs pi Go Tact H Tadas Q Gerting Gating Grease Yee He BAr B 6 85 SSSA SEBEL LALETA LAL i e 1 Tre BR LLEALSE LSE LLL LS eB ea a B48 BEERS aee 8 F z 22 aqQu iDERP T z Ph RE 2 b ib Po ks s por 56 sad 6 aes J i W i T f l ub F 3 p oe rd x d a i p ub SSS OOM So m 00 semen pu TE AEA dm Meter tet tert ee a Pade Ch a 17 28 Wireless packet transmissions IEEE 802 11 DATA frame Fae Ede G Teos A Poor G Esg Hi Daing Spereteron yew hip j tBAw B 8 5 se EF Bebe e Bees Tae ij amp e Tre SE LLALLA LS ITELLA ea Bi SERRE ee ee 2 FARA Lea DER P 8 so ik z ri ab k x a r 4 E brt Sa 6 W cee y r 4i r a f wb A s i Saa uF ie ub Gat wa oe oot A A b a IF LL 1S 5 Ebie Ie ees ere Mide IG 1E Wireless transmission IEEE 802 11 ACK frame e Two concentric circles are centered at a transmitting node The smaller circle stands for the transmission range while the larger one stands for the interference range Within the interference range a station can sense the existence o
141. cl Therefore the absolute file path of this file e g usr local test cfg should not be given in the command string as an argument to the application Rather only its file name i e test cfg should be given in the command string For example the command string should not be something like stg 1 usr local testuser trace cfg This is because the GUI machine and the simulation machine may be different machines and use different file systems An absolute file path used in the GUI machine may refer to nothing on the simulation machine Since the simulation engine will store the specified configuration file in the working directory of this simulation case which is also the working directory of all forked application programs for this case the file name given to the application program can be and should be the file name only without any path specifi cation As for the Down time tab a user can set the intervals during which the node is down cannot send and receive any packet The down time periods specified here will be propa gated and set in the PHY or WPHY modules of all of the 25 node s interfaces This is because the PHY or WPHY modules are the right place to disable or enable the trans mission and reception of packets The dialog box of the Phy module is shown below a Fa e TAE Module Edit DO Parameters Setting Bandwidth Mbps Bit Error Rate 0 0 OK
142. clusive to each other Wirtual Router Le feel Extemal Router ID l E Use a real router to connect multiple emulation n Edit x Nods editor OK Cancel If the virtual router is used to represent a real router one should tick the Use a real router to connect multiple emulation machines option to enable the top panel On this panel one can specify which machine is used to emulate a part of the network For each port of the virtual router it has a corresponding entry in the table on the first panel Each entry comprises five fields 1 Port ID 2 Assigned IP address in the emulated network 3 Coordinator IP address 4 Emulation machine IP address and 5 the IP address of the network interface on the real router that corre sponds to this port The meanings of these fields are explained below The Port ID field denotes the ID of the port under discussion The Assigned IP address field shows the assigned IP address for this port in the emulated nework The values of these two fields are automatically assigned by the GUI program The Coordinator IP address field specifies the IP address of the emulation machine whose coordinator program is responsible for forking a simulation engine process to emulate the part of network that this port connects with If such an emulation machine has multiple IP addresses i e it has multiple network interfaces participating in the distributed emulation See Example 3
143. ction with the host 1 0 2 1 and the host 1 0 2 2 wants to establish a TCP connection with the host 1 0 3 1 Similar to example 1 this example case also has two possible physical network configurations One is using a real router to connect the three emulation machines and the other is using a switch to connect the three emulation machines The steps to configure these two cases are explained in detail below Use a real router to connect emulation machines As shown in the following figure the example network is composed of three emulation machines and one real router The IP addresses of these three emulation machines are 192 168 1 1 192 168 2 1 and 192 168 3 1 respectively These emulation machines connect to the real router at its three interfaces The IP addresses of these interfaces are 192 168 1 254 192 168 2 254 and 192 168 3 254 respec tively In this example the dispatcher program and the GUI program are run on the emulation machine with the IP address 192 168 1 1 68 TCP Connection Emulation Machine 192 168 1 1 Sgeeece s Emulation Machine Emy tion Machine Ss _192 168 2 we 192 168 3 1 1 e After configuring the physical network links one should execute the following route commands on the real router route add net 200 1 2 0 24 gw 192 168 2 1 route add net 200 1 3 0 24 gw 192 168 3 1 route add net 200 2 1 0 24 gw 192 168 1 1 route add net 200 2 3 0 24 gw 192 168 3 1 route
144. d antenna is an omni directional antenna In this case the antenna icon is shown as 360 degree circles If a 3db beamwidth 60 degree directional antenna is used only 60 degrees out of 360 degrees of the above antenna icon will be shown and its pointing direction is the pointing direction of the directional antenna A 3db beamwidth 120 degree directional antenna A iS displayed in the similar way More information about direc tional antennas will be discussed in a later chapter When the user switches the mode to the Edit Property mode the GUI program will automatically generate and assign an IP and MAC addresses to each port interface of a layer 3 device e g a host or a router In this mode if the user moves the mouse cursor and place it over the interface either a blue box or an antenna icon for a while the port s information i e its port ID and assigned IP address will be 21 shown on the screen Note that the information shown for a layer 1 port e g a hub port or layer 2 port e g a switch port contains only the port ID information This is because such ports do not have IP addresses assigned to them In a real world network environment a mobile node may move A mobile node may be an IEEE 802 11 a WLAN ad hoc mode mobile node an IEEE 802 11 a WLAN infra structure mode mobile node an IEEE 802 11 b WLAN ad hoc mode mobile node an IEEE 802 11 b WLAN infra structure mode mobile node an multi inter
145. d colored dotted arrow C P gt from the chosen node to a potentially interfered node Note that such an arrow from a node X to a node Y only indicates that node Y will be interfered by the node X s packet transmission activity which does not guarantee that node Y can successfully receive packets transmitted by node X That is node Y can sense node X s packet transmission which is likely to hinder node Y s packet receiving activity if they occur at the same time On the other hand if node X intends to transmit a packet to node Y node Y can sense this activity and start its receiving procedure to receive this packet However this does not necessarily mean that node Y can correctly receive the packet The success of receiving node X s packet is deter mined by many dynamic factors e g the used modulation technology the BER resulting from background noise trans mitting power the adopted antenna gain pattern etc Since these factors can be dynamically changed during simulation the GUI program cannot compute and display each node s effective transmission range when drawing a topology The effective transmission range of a node means that within it packets transmitted by the node can be successfully received by its 1 hop neighboring nodes in case no packet collisions occur The following figure shows a snapshot when the Use the transmitting node perspective mode is used fe Ee Ej a Ha ee a eee ee jy XA eo ea at
146. d in the packets that leave the current DS domain so that the boundary router in the next DS domain can correctly mark them The following figure shows this type of protocol stack Node Editor QO Q x MAC80211 YWPHY 80211P YAP VARP DVB_S2 FEEDER V DVB_S gt am _ KI Select Mode H k xX Undo Redraw CTAP C T AN The protocol stack of a DiffServ boundary router MAC8023 MAC8023 V Node Editor a eX MAC80211 WPHY 80211P VAP VARP DVB_S2_ FEEDER VDVB_S lt SPR E m i E Select Mode AI Xll DiffServ Protocol Module ARP ARP A user need not set any parameter in the dialog boxes of the DS_TC DS_I and DS_REMARK protocol modules The required parameter values should be specified in the DiffServ configuration file described before MAC8023 MAC8023 reepume TePDUMe Summary This chapter presents how to use NCTUns to conduct QoS DiffServ simulations A DiffServ network can provide differentiated quality of services to different traffic classes Such a network is composed of boundary and interior routers A boundary router is responsible for classifying and conditioning traffic while an interior router 1s responsible for scheduling packets It is out of the scope of this chapter to explain the details of DiffServ Readers should reference some textbooks to understand the meanings of various The protocol stack of a DiffServ interior route
147. d network the user must first activate the phone so that a PDP Packet Data Protocol context is installed in the chosen SGSN and GGSN for routing After the activation the user may update the QoS level of the phone s traffic When the data transfer is completed the user can deactivate the phone and then detach the phone from the GPRS network These five commands are provided in the Action tab of the phone s dialog box The following figure shows the dialog box of this command fee Bet p Tafi anes aieg fi beieg Epmdghon Yee pn _XAroe U Sa DE He Sev aww Pp a eeu wii a rrc oon8 TWILL G LL SIL SALA Lae Sse Bee BeBEEBERtr BBA ARR E ee DER P TALE on Because internally a phone functions like a host any real world application program can be run on a GPRS phone As such a user can specify an application command string something like the following stcp p 8000 1 0 3 2 in the Application tab where 1 0 3 2 may be the IP address of a host in the fixed network Note that the start time of any specified application program must be later than the start time of the phone s attach action command Otherwise the packets of the launched application program will not be accepted by the GPRS network Base Station In the Frequency Channel tab of the base station dialog box a user can specify a range of frequency channels allocated to and used by this base station This range is specified by the starting and endi
148. d separately in another chapter To represent them in an emulation network topology these devices have their own node icons which are shown here 9 ew gv In addition to the above usage two real world hosts including mobile hosts in the following discussion can exchange their packets via a simulated network For example a TCP connection can be set up between two real world hosts with their packets traversing a network simulated by NCTUns in real time Emulation provides several advantages First real world traffic and simulated traffic can interact with each other Second real world traffic can be subject to user specified packet delay drop reordering and packet scheduling and or buffer management schemes With emulation we can test the function and performance of a real world host actually the host can be any device with an IP address and see how it would perform under various network conditions without getting knowing or modifying its internal protocol stack Emulation is achieved by 1 specifying to which node in a simulated network an external host router should be connected 2 physically connecting the external host router to the simulation machine via a network 3 setting the speed of the simulation engine to be as fast as the real world clock 55 and 4 add some settings on the simulation machine and external real world hosts routers so that real world traffic can be directed to and received from the simulated
149. de a user can edit the property of a node For example he she can specify which protocol modules should be used inside a node and what values should be used for the parameters needed by these modules A user can also specify the application programs that should be run up on a node during simulation However in this mode a user can no longer change the topology of the network that has been fixed in Mode 1 Mode 3 Run Simulation In this mode a user can run pause continue stop abort disconnect reconnect submit a simulation in this mode No simulation settings can be changed in this mode Mode 4 Play Back After a simulation is finished the ptr packet animation trace file will be automatically sent back to the GUI program The GUI program will then automatically In this play pause continue stop the packet transfer animation The d DERP buttons on the tool bar corre spond to these four different modes respectively If a user enter into this mode mode the user can needs to switch the operating mode very often among these modes it will be more convenient to click one of these buttons to switch into that chosen mode At any given time one of these buttons will be displayed in blue color This reminds the user of the current mode When a simulation is running all of these buttons will be temporarily disabled They will be automatically enabled when the simulation is finished stopped or aborted Adding Nodes with the Tool
150. ded in the same way like adding an arrow With obstacles a user can simulate a more complicated and interesting field setting This can facilitate testing wireless network and protocol performances e g handoff under a more realistic field setting BAe E4 88 SE Sea RSA REY SO Beebe AS LI i e BERS FE SPR LLELLA LE LLL LS eee ee BRRERSHR EGP BET YAS BSA Ee DERP ir p i 1A oe aaa A Ali ee eS Communication between the two mobile nodes is affected by the obstacle located in the middle of them Note that the single hop connectivity and multi hop connec tivity calculations provided in a mobile node s dialog box take into account the existence of obstacles In addition the God routing daemon for WLAN ad hoc mode mobile nodes takes into account the existence of obstacles as well The name of the file that describes the obstacles in a simulation case is XXX obs If a user clicks and holds on one side of an obstacle a yellow square box will appear at that side and he she can rotate or extend the obstacle Another side of the obstacle is the fixed point of the rotation or extension operations If a user clicks on the middle part of an obstacle a yellow square box will appear at both sides and he she can move the selected obstacle to any place If a user double clicks an obstacle a property dialog box will pop up A user can specify the obstacle s properties such as its width whether it should b
151. directional antenna for antenna should be properly set to obtain a better gain so that a better communication quality can be achieved One common way to describe the coverage of the main lobe for a directional antenna is using the 3 dB beamwidth value The formal definition of the 3 dB beamwidth is exactly the 3 dB beamwidth which is given as follows 3 log10 p pmax where pmax denotes the maximum power value achieved in the main lobe and p denotes the power value achieved by the antenna at a specific angle Note that the pmax and p values are normalized to a reference power level generated by an omni directional antenna According to this definition the p value is approximately a half of the pmax value As such the 3dB beamwidth denotes the range of emission angles within which an antenna can generate transmission power gain that is at least half the maximum transmission power gain that it can generate The following figure shows the three default types of antennas supported by NCTUns 1 omni directional antenna 2 120 degree 3 dB beamwidth directional antenna and 3 60 degree 3 dB beamwidth directional antenna As one sees the circular radio wave icon denotes the antenna used by the node is omni directional In contrast the 120 82 degree sectored radio wave icon and the 60 degree sectored radio wave icon denote the antennas used by the nodes are 120 degree and 60 degree respectively in terms of their
152. dule Set node port module tag value Get get the value of a variable from a module Get node port module tag Get All like Get but get the values of the requested variable from the same modules used in all ports of all nodes GetAll module tag Simulation Note that a tag is a string associated with a particular variable declared and used in a protocol module A variable here can be a single value variable e g a FIFO queue s maximum queue length or a multi column multi row table e g a switch table that has multiple IP address MAC address mapping entries It is the protocol module developer s job to write a command method in his her module to recognize a tag and then get set the value of its associated variable M Packet Trace Log File Format Ome G The printPtr utility program can convert a binary packet transfer log file ptr into a readable text file This enables the user to observe each packet transmission s 1 starting time 2 ending time 3 real source node ID 4 real destination node ID 4 intermediate source node ID 5 intermediate destination node ID etc 1 The format of the lines in a converted file Field 1 lt protocol gt 802 3 802 11 OPHY GPRS Field 2 lt event type gt TX transmit RX receive RTX re transmit BTX broadcast transmit BRX broadcast receive DROP drop Field 3 lt time unit tick at which the ev
153. e FINALCHECK file This file lists the important operations that the user must have performed to run NCTUns correctly According to our technical service experiences almost every reported problem is caused by not performing all of these required operations More detailed and up to date installation and usage infor mation can be found in the NCTUns package A Quick Tour Setting up the environment Suppose that a user uses the single machine mode of NCTUns before he she starts the GUI program he she must perform three operations 1 Set up environment variables Before a user can run up the dispatcher the coordinator and the GUI programs he she must first set up the NCTUN SHOME environment variable To do so a user can type in and execute the setenv NCTUNSHOME usr local nctuns shell command in his her terminal window i e xterm if the csh or tcsh shell is used For the bash shell the command should be export NCTUNSHOME usr local nctuns Two other environment variables must be set as well The first is NCTUNS _TOOLS and the second is NCTUNS_BIN They must be set to usr local nctuns tools and usr local nctuns bin respectively For a user s convenience the installation script will place the nctuns csh and nctuns bash file in usr local nctuns etc when the installation is completed The user can use the command source usr local nctuns etc nctuns csh to set these environment variables if his her
154. e Nodes gt Insert 802 16 d PMP Mode Nodes Ss o a Ae x opuuabee po Sa eee Fae jf we none TALE LB ALSALS FSB e we is i he RARER COERP i E o m om G a lee In the dialog box shown in the following figure one can specify 1 the type and the number of the inserted nodes 2 the positions where the nodes should be placed and 3 the protocol specific settings that should be applied to each node Specify and Manage IEEE 802 16 d PMP Subnets Like in the IEEE 802 16 d mesh network the GUI user must use the form subnet tool to group together the PMP BS node and the PMP SS nodes to form a subnet Doing so allows the GUI program to automatically generate IP addresses for these nodes saving the user much time and effort Specifying and managing IEEE 802 16 d PMP subnets uses a procedure similar to that for IEEE 802 16 d mesh subnets Please refer to the previous section Manage IEEE 02 16 d Mesh Subnets for detailed information 155 Specify Maximum Transmission Range For IEEE 802 16 d PMP Nodes Specifying the maximum transmission range for IEEE 802 16 d PMP nodes uses a procedure similar to that for mesh nodes Please refer to the previous section Specify Maximum Transmission Range For IEEE 802 16 d Mesh Nodes for detailed information Specify Sustained Rates For IEEE 802 16 d PMP SS Nodes Currently the data scheduler used in t
155. e and High Fidelity TCP IP Network Simulators Computer Networks Vol 40 Issue 2 October 2002 pp 257 278 3 S Y Wang NCTUns 1 0 in the column Software Tools for Networking IEEE Networks Vol 17 No 4 July 2003 4 S Y Wang C L Chou C H Huang C C Hwang Z M Yang C C Chiou and C C Lin The Design and Imple mentation of NCTUns 1 0 Network Simulator Computer Networks Vol 42 Issue 2 June 2003 pp 175 197 5 S Y Wang and Y B Lin NCTUns Network Simulation and Emulation for Wireless Resource Management Wireless Communication and Mobile Computing Wiley Vol Issue 8 pp 899 916 December 2005 6 S Y Wang and K C Liao Innovative Network Emula tions using the NCTUns Tool as a book chapter of the Computer Networking and Networks book ISBN 1 59454 830 7 published by Nova Science Publishers 7 S Y Wang C L Chou C C Lin The Design and Imple mentation of the NCTUns Network Simulation Engine Elsevier Simulation Modelling Practice and Theory 15 2007 57 81 2 Getting Started his chapter presents a simple tour to help readers quickly learn how to use NCTUns First we give instructions on how to install NCTUns on a single machine Next we present step by step instructions to illus trate how to quickly run up a simple simulation case Installation and Configuration In the following we assume that when installing the package the u
156. e bottom of the screen As the packet animation proceeds the performance monitor window will display the corresponding performance curves over time Note that the performance monitor can be used as an independent tool without the animation player running That is it can read a log file generated by any other application program as long as the log file uses the two column X Y format 51 Operations on the Performance Monitor Several other commands are provided in the menu of the performance monitor window In the following we will explain their usages PM Menu gt File ohapshot All New When a user executes this command a new graph window will be opened Up to six graph windows can be shown on the screen at the same time Open A user can execute this command to open a desired log file as a graph window s data source file The specified log file will be associated with the graph window Normally log files are generated by the simulation engine if the user selected to do so in some protocol modules e g 802 3 or 802 11 modules in the node editor However they can also be generated by application programs running on nodes such as rtg Open FS e e Look in amp root test example01 example01 results E Ga J example 1 cfg FB armnple0l N2 P1 InQutThrput log J exarmple 1 config Ljexamplett 8023 N3 Pl InQutThrput log LJexarmple01 dvbres freq JexarnpleQl arp LJexarnpleQl bsscfg
157. e car with an 802 16 e mobile wimax interface and M car with all different types of interfaces One can deploy ITS cars on a road network one by one This can be done by first clicking the desired type of ITS car icon on the tool bar and then clicking the desired location for it on the road network Note that one must be very careful when placing ITS cars An ITS car must be placed on the roads can be any type of road objects otherwise the car agent 140 program which controls the movement of the vehicle that it controls cannot detect on which road it is moving during simulation The functions of the car agent program are explained later The six different types of ITS cars supported by NCTUns Using the above manual method to deploy a large number of ITS cars will take a user much time and effort To overcome this problem NCTUns provides a convenient tool which can automatically and randomly deploy a large number of ITS cars on the road network for users The path of this tool is Menu gt N_Tools gt ITS Network gt Deploy cars automatically URA a ay ck a t ee oe es nonn HELa LA LLY FSi Re we CELLE i ARERR Se OERP Ss _ 1m mmo QQ de ieee The following figure shows the dialog box of this tool In this dialog box one can specify what types of cars should be deployed the deployment density and the maximum number of the deployed cars Note that the actual number of deployed cars may be smalle
158. e concept of protocol modules and the node editor The node editor is an environment in which a user can flexibly configure the protocol stack and parameter values used inside a node NCTUns provides some pre built protocol modules A user can easily add his her own protocol module to the node editor to test its performance 5 Packet Animation Player fter a simulation execution is finished the generated simulation results will be automatically transferred back to the GUI program and then saved in the user s local hard disk Suppose that the simulation case s topology file is named test tpl Then the name of the resulting packet animation trace file will be test ptr Later on when the user wants to do post analyses about the simulation results he she can use the Packet Animation player to play back the animation This is a very useful feature for both education and research purposes Reloading Simulation Results To watch a previously generated packet animation trace a user should first open its corresponding topology file Menu gt File gt Open Look in a root 6 0release Demo01_Twolnfra LJ Demo01_Twolnfra results J Demo01_Twolnfra sim MM Demo01_Twolnfra tpl File name Demoo1 _ Twolnfra tpl File type topology file tpl Cancel The user then switches to the Play Back mode directly The GUI program will then automatically reload the simulation results including
159. e different charac teristics Therefore we demonstrate their corresponding animation effects separately Wired Network We use two screen shots to illustrate and explain wired network packet animation T s bai fmi At mie G Tag H bern Geer y pie S Fra EAL bt SSSA BERRY S LIITE EL SELL BEEBE tre JH LLALLA LE LLEL LS aaa Bae BRR EGP BEN AREAS RE MBIDERP 109 1 0 E EEL Se PP PMI Ers D I z ns AY va b Il E Hh Him E UTS Eh Successful packet transmissions Cee bh Glens Peds ng n Genie Yee fee BAvw B a 5 5 Bes SERB O Beekhe Lae i se BERR Fre SU LLELLS LS LLELLS eae a eae ERP TELL CESS Bar eee Se ee Se Pg a WELEH E erat ans ne G ses sa von val A A ab Il Bice a Packet drop amp collision represented by cross e A link is painted in yellow color if there is any packet flowing on it e A packet is depicted by a segment with an arrow for brevity it will be called an arrow in the following description e A collided packet is depicted by an arrow with across on it e During a packet transfer if a link is painted in red it means that this link is an intermediate link for this packet In contrast if this link is painted in yellow it means that one end of this link is the real source or destination node of the packet e The arrow length is determined by the packet s length Therefore a user can expect that the arrow length is proportional to the pa
160. e filled with 10 0 0 2 Suppose that the external machine wants to make a tcp connection to a host in the simulated network whose IP address is 1 0 3 4 Then on the external machine one should first execute the following command to add the needed routing entry to the routing table Linux route add net 1 0 0 0 16 gw 10 0 0 1 Free RSM route add 1 ANZIA 1N NN 1 Node Editor Cancel Direct Traffic to the Simulated Network Suppose that in the real world the simulation machine s IP address is 10 0 0 1 and the external machine s IP address is 10 0 0 2 and they are physically connected via a crossover Ethernet cable Suppose that the external machine wants to make a TCP connection to a node in the simulated network whose assigned IP address is 1 0 3 1 Then on the external machine the user should first execute the following FreeBSD command to add the required routing entry to the system routing table route add 1 0 16 10 0 0 1 In the above command 1 0 16 means that the destination network address is 1 0 X X 16 means that the netmask is 255 25 0 Note that every node in the simulated network is assigned an IP address of the form of 1 0 X X As a result the above command indicates that all outgoing packets whose IP destination address is 1 0 X X should be first sent to the gateway whose IP address is 10 0 0 1 In this case since 10 0 0 1 is the simulation machine s IP address these packets will be sent to and received by
161. e following information for users 1 the distance between the chosen node and each other node 2 the antenna gain values for each pair of nodes 3 the interference range of each node from the perspective of the chosen node and finally 4 the CRPT value of each node from the perspective of the chosen node Note that the meanings of the 2nd 3rd and 4th items depend on whether the Use the transmitting node perspective mode is used or the Use the receiving node perspective mode is used For example suppose that the chosen node is node and the first entry of NDPIT is for node 25 When the Use the transmitting node perspective mode is used the TxGain value denotes the antenna gain value of the chosen node 1 and the RxGain value denotes the antenna gain value of node 25 On the other hand when the Use the receiving node perspective mode is used the 7xGain value denotes the antenna gain value of node 25 and the RxGain value denotes the antenna gain value of the chosen node 1 Similarly when the Use the transmitting node perspective mode is used the interference range denotes the maximum range that the chosen node can interfere with node 25 and the CRPT value denotes the minimum power threshold value that node 25 should set if it wants to be capable of sensing the transmission activity of node 1 In contrast when the Use the receiving node perspective mode is used the interference range denotes the max
162. e g the used frequency channel and the wireless signal transmission range The C P A N S T button stands for Copy the Parameters to All Nodes of the Same Type If a user executes this function the parameters used by this WLAN mobile node will be copied to all WLAN mobile nodes with the same operating mode i1 e ad hoc or infrastructure That is the parameter values of all other WLAN mobile nodes with the same operating mode will be replaced by the current one For example if the current WLAN mobile node is an ad hoc mode mobile node its parameter values will be copied to and only copied to all other ad hoc mode mobile nodes The C P A N S T is a useful function Suppose that a user wants to compare the performances of two different routing protocols A and B he she may attempt to test the perfor mances of these two protocol modules under the same network topology and configuration That is the initial locations and the moving paths of all mobile nodes in these two cases should be exactly the same the difference should be only in the used protocol stack With this function this task can be easily done in the following steps 1 The user first tests the performance of protocol module A in a simulation case 2 The user 30 executes the Menu gt File gt Save As command to save the current case into another one 3 In the new case the user invokes any mobile node s node editor to replace protocol
163. e movement IM Block wireless signal Block signal completely D Attenuated by Width lo d In the dialog box there are three check boxes related to the three properties mentioned above Note that if block wireless signal property is enabled i e the Block wireless signal option is checked one of the two options block signal completely and attenuation by x dbm in the following box should be set where x denotes the amount of the signal strength attenuation If the first option is set this obstacle will block the wireless signal completely that is to say the wireless signal cannot pass through this obstacle at all If the second option is set the amount of signal strength attenuation caused by this obstacle should be specified At the end of the obstacle dialog box is the field used to specify the width of the obstacle in pixel An Example of Tactical MANET Simulation In the following figure one can see a scenario of the tactical mobile ad hoc network There are two mobile nodes located in a maze filled with many obstacles One mobile node is the chasing node while the other is the target node Specify a Tactical Agent Program for Each Mobile Node For each mobile node one has to specify a tactical agent program running on it via the Application tab which is in the node s dialog box For example as shown in the following figure we specify that
164. e of a transmitting node while using the second mode one can observe the radio connec tivity from the perspective of a receiving node The difference between these two modes will be explained below soon One can specify the node connectivity display mode in the Node Connectivity Display column which provides two options Use the transmitting node perspective and Use the receiving node perspective Choosing the former asks the nctunsclient program to display node connectivity from the transmitting node perspective while choosing the latter asks it to display node connectivity from the receiving node perspective The following figure shows the location of the Node Connectivity Display column ne Specaty physical layer ard channel sodel parameters Precept CAAA Mi Treweical Gure Moda Path Lowe Hosa le Tuag Furr argum Fairy Miei i Mone HEESE Erie Onana bhia Txantennaiieght mi SytemLess Mode Conmecthety ispir TransPrewer demi Use the branaritting rode perspective Libe the fecii PoE Gerepectnne Aripi n Sheela teal Aveageiuldrgiastance inl Pathos leponenit Antenna Gan Patten ard Girectsity stondaa Coselniistance im Transmitting Node Perspective If the Use the transmitting node perspective mode is chosen the GUI program will show which nodes will be interfered by the chosen node the clicked node in case it is transmitting a packet This is accomplished by drawing a re
165. e set to UDP the Direction has to be set to Uplink the Source port number has to be set to Don t care the Destination port number has to be set to 8000 the Traffic stream ID has to be set to one of the values ranging from 8 to 15 the Mean data rate has to be set to 200 KB sec and the Nominal packet size has to be set to1024 bytes because the greedy UDP traffic generator sends packets with 1 024 byte data payload Here the Delay bound represents the maximum period of time from the arrival of a MSDU Mac Service Data Unit at the local MAC layer to the completion of the MSDU s transmission The Maximum service interval is the maximum interval between the starts of two successive polling periods According to the specification if both of the Delay bound and the Maximum service interval are specified only the latter will be used If the user wants the access point to poll the mobile node every 20 ms the Maximum service interval should be set to 20 ms and the Delay bound can be left empty According to the sample scheduler described in annex K 3 3 of IEEE Std 802 11e 2005 the maximum data transmission period that can be granted to a traffic flow is 8 160 microseconds This means that a mobile node cannot seize the medium for more than 8 160 microseconds to transmit its packets even though it may have many packets to transmit If the access point has enough available bandwidth to satisfy the QoS demand of a traffic fl
166. e_Space Two_Ray_Ground and Free_Space_and_Shadowing and three different fading models no fading None Rayleigh Fading and Ricean Fading The other model class is the Empirical Channel Model class which collects channel models that are developed based on real life measurement results So far NCTUns supports 23 empirical channel models e g LEE Microcell Okumura COST_231 Hata and so forth Users can choose one of them to simulate wireless channels by choosing the items shown in the list In addition to setting the channel model used in simulation here alternatively one can choose and configure the used channel model via Node Editor For context consistency we do not present how to specify a channel using this approach here Instead we leave the introduction to this approach and more detailed information about a channel model in the next chapter Recalculation and Display for Node Connectivity After finishing configuring antenna and channel model settings one can click the Recalculate button to ask the GUI program to perform the CRPT value calculation when the Use the transmitting node perspective mode is chosen or the CCSPT and CRPT value calculation when the Use the receiving node perspective mode is chosen In addition one can also click the Show button to show the Node Distance and Physical layer Information Table NDPIT NDPIT shows th
167. eal router to connect multiple emulation n 0 iess 192 168 1 1 192 168 2 1 192 168 3 1 natorhte R Router IP addr 192 168 1 1 N2 168 1 254 Eat 192 168 2 1 19 168 2 254 192 168 3 1 Node editor Cancel following figure the dispatcher program and the GUI program are run on the emulation machine with the IP address 192 168 1 1 Emulation Machine 192 168 1 1 ah Salta ad MN Emulation Machine Emp tion Machine Ss 192 168 1 2 ae 192 168 1 3 The next step is to change the DISPATCHER_IP parameter of each coordinator cfg file from 127 0 0 1 to 192 168 1 1 for each involved coordinator program This is to make sure that each involved coordinator will register itself with the same dispatcher program One then starts all coordinator programs on their respective emulation machines After this is done one can run up the GUI program on the emulation machine with the IP address 192 168 1 1 and properly specify the Dispatcher IP address in the Menu gt G_setting gt Dispatcher panel After drawing the topology of the emulated network and specifying the traffic setting one double clicks the icon of the virtual router to pop up its dialog box Because the virtual router now does not represent a real life router one should enable the Let multiple emulation machines communicate with each other directly option The detailed setting of this dialog box for this example is shown below Virtual Router
168. ec tively In addition the valid period in superframe for a RBDC request should be set in this box amp Capacity Setting for RCST Request Categories Supertrame ID il Remaining capacity 844800 bps RCST ID i Allocated maximum CRA capacity Granted maximum YBDC capacity 998400 bps i OK Granted maximum RBDC capacity 460800 bps LJ Valid period for a REDC request 2 supertrames elles The mechanism of Free Capacity Assignment FCA can be enabled by checking the option of Use Free Capacity Assignment on the tab of Return link capacity The following figure shows where the option is Return link arrangement Grouping Return link capacity Each channel s maximum transmission capacity is approxiarr _ Use Free Capacity Assignment Limitations on RCST Capacity Channel Superframe ID RESTID Max CRA bps Max VBI 1 11 1996800 598400 1 22 598400 598400 17 15 7005700 1506AN After completing all of the channel capacity assignments one can examine the final assignment results on the tab of Return link capacity The assignment results will be automatically removed when one changes the parameter values on the tab of Return link arrangement because they will affect the maximum transmission capacity of a channel Also changing the grouping relationship will remove the existing assignment results This is because the old assignment may no
169. ectively which are located in ust local nctuns etc agp bv default A In this dialog box one can specify 1 the 3 dB beamwidth 2 the orientation 3 the rotating angular speed and 4 the gain pattern of an antenna The meanings of these attributes are explained in next section On the other hand if one intends to configure the antenna properties of all nodes at the same time one can use the Antenna tool to set up all nodes antennas once The dialog box of the Antenna tool is the same as that shown in the above figure however the setting that one configures in its dialog box will be automatically applied to the antennas of all wireless nodes The command path of the Antenna tool is Menu gt G_Setting gt Antenna 003 frootyNCTUns 5 o examples Demod Antenna _Simplewphy Demo G Setting N_ Setting Simulation wiew Help Dispatcher Simulation Obstacle may block wireless signal view orfand movement Background Graph Save Settings Directional Antenna Concept A directional antenna is an antenna that can generate different transmission gains in different directions and can generate higher gains in particular directions so called the main lobe Due to this property it can provide a longer transmission range and reduce signal interference in its neighborhood as compared with an omni directional When communication the transmission receiving direction of the antenna using a
170. ed the absolute file path and file name of its configuration file must also be entered with all other infor mation Otherwise the GUI program will not have the intel ligence to also move the needed configuration file to the remote or local simulation server machine Specifying the absolute file path and file name is best done via the browse function in the dialog box of the Add command For example suppose that when the stg application program is executed it wants to read in a configuration file named trace cfg and this file is located in usr local testuser Then DO Q Host ID Name Application Downtime Mobile IP Start time s Stop time s Command Input file name Add Modify Add RTP Modify RTP Delete App Usage ale Node editor OK Cancel The dialog box of hosts the entered command string should be something like stg i and the Input file name field should be 99 99 trace cfg usr local testuser trace cfg which can be completed by using the browse function Note that the purpose of providing the absolute file path and file name in the Input file name field is for the GUI program to successfully locate it and transfer it to the simulation server machine On the simulation server machine the transferred file is placed in the same directory as all other simulation description files such as t
171. ed at an optical edge router To assemble a burst several packets need to be accumulated to make a burst large enough The Maximum Burst Length MBL field specifies how many bytes of packets need to be accumulated before a burst can be sent out To avoid too much delay a short burst should still be sent out after a certain period of time even if its length is still less than MBL The Timeout to Send a Burst field specifies this timeout period When packets arrive at an optical edge router at a rate higher than the rate at which bursts can be sent out they need to wait in a queue to be assembled The maximum length allowed for this queue is specified by the Maximum Queue Length field When a packet arrives but finds that the queue is full it will be dropped In an OBS network control packets and their burst data packets are sent over different wavelength channels In this module a user can specify these channels Module Edit Parameters Setting Control Packet Processing Time 2 ns Optical Burst Assembly Timeout to Send A Burst ho us Minimum Burst Length MBL byte Maximum Queue Length boood byte Wavelength Channel Assignment Maximum Number of Channels 3 Control Packet Channel Data Packet Channel 2 Configuration Files Node Type File ch15 nat Node Connection File Jenis gph Protection Ring File ch15 osr shortest Path File chi5 osp The parameter dialog box of the OPT_OBWA protocol modu
172. ed on the DiffServ codepoint bit pattern marked on its TOS field which is marked when the packet passes through a Diffserv boundary router Several forwarding treatments or called PHB are defined and provided for a Diffserv network They are best effort BE Expedited Forwarding EF and Assured Forwarding AF The service provided by BE PHB is equivalent to the best effort service provided by the current Internet The service provided by EF PHB can be described as premium service by which the packets of a traffic flow will experience very tiny delays and no packet loss The services provided by AF PHB is to forward the packets of a traffic flow with high assurances This service is better than the BE service but worse than the EF service DiffServ is composed of several schemes and protocols This chapter only provides a brief overview of DiffServ For more detailed information about DiffServ readers should reference 1 2 3 4 DiffServ Network Creation In the following figure two DS domains exist One is on the left while another is on the right Boon y ian j baug fe ee to p ee T S IET E ETTET TEET Ber i gw fF ch OE Bea eBESA She SMI Le AL a ee ea Ss Domain A Domain B 3 EEE A A 4 iah a 4 When a user inserts a boundary router or an interior router into the working area the GUI will pop up a dialog box asking the user to specify the name of the DS domain that this router belongs to
173. eds to double click the NCC node In the popped up dialog box shown below one has to choose the tab of Return link assignment On the top half of this tab one has to set the range of superframe ID The number of superframes determines the number of channels used on the uplink downlink of the return link One also has to set the central frequencies for the whole uplink and downlink frequency bands The bandwidth of each channel is deter mined by setting the symbol rate and roll off factor applied on each channel The resulting value of each channel s bandwidth is calculated by the following equation bandwidth symbol rate 1 roll off factor K H a Retem fink arrangement Growing Aelum bnk capacdy Actum ink frequeney Forward link arrangement Range of supertrame ID 0 4 rom 1 bo 2S CV ACS Aiwork Control Genter ie There are 5 channels over the retum nk Cemral frequency of ike whole return uplink channel bond 41 GHE Central frequency of tbe whole return downink channel bna 25 GHE Symbal rate per channel SSS5000 symbaser Rol off factor a ach channel s bandwidthis 1300c tsa Hr Menber of ATM celia per slet i z Preambie length l symbolls i Burst start oiae quand tine i symbols iiom 1 te 2040 The stnacture of a stot Nemniber of Data sotis per fame So Member of Request stis per frame 5 Mortver of ramels per supertrame 10 imam lta 32 oding Modulation Reed soleenon Error Cor
174. el Channel Capacity Partition for RCSTs Superframe ID Remaining capacity bps 8448200 1305600 4300800 Set RCST Capacity Cancel The following figure shows the popped up dialog box when clicking the Set RCST Capacity button This box shows the current capacity assignments for all RCSTs that issue receive signals on the given channel If one wants to change the assignment he she can click the Set Capacity button Capacity Setting for RCST Using the Same Channel Superframe ID Remaining capacity 844800 bps RCSTID CRA YBDC RBDC RBDC timeout 11 1996800 998400 460800 2 22 998400 998400 998400 2 Set Capacity T eecesseececscoeecee According to the DVB RCS standard 1 five capacity request categories are proposed CRA Continuous Rate Assignment RBDC Rate Based Dynamic Capacity VBDC Volume Based Dynamic Capacity AVBDC Absolute Volume Based Dynamic Capacity and FCA Free Capacity Assignment Each category provides different QoS guarantees for a RCST to satisfy different type of traffic flows e g real time constant bit rate etc Except for AVBDC the other four capacity request categories are supported in the current implementation of NCTUns The following figure shows the popped up dialog box when one clicks the Set Capacity button after choosing a RCST One has to specify the maximum capacities that a RCST can request for CRA RBDC and VBDC traffic flows resp
175. elect the configuration file DiffServ Domain Configuration File Format Fifteen codepoints are provided in NCTUns They are for BE best effort EF expedited forwarding NC network control and 12 AF Assured Forwarding services Assured Forwarding AF PHB group provides forwarding of IP packets in 4 independent AF classes Within each AF class an IP packet can be assigned one of 3 different levels of drop precedence An IP packet that belongs to an AF class 1 and has drop precedence j is marked with the AF codepoint AFjj These PHB services and their corresponding codepoints are listed as follows PHB service Codepoint AFI 001010 001100 001110 AFIT AF12 AF13 AF2 010010 010100 010110 AF21 AF22 AF23 AF3 011010 011100 011110 AF31 AF32 AF33 AF4 100010 100100 100110 AF41 AF42 AF43 EF 101110 NC 111000 110000 101000 100000 BE 000000 In the DS domain configuration file multiple DS domains can be defined The definitions of each one are specified in the following format DefineDSDomain Name Enter_A_DS_Domain_Name_Here RuleAdd sip dip sport dport proto PHB rate Mbps size Mb maxgqlen RuleAdd QueAdd type name weight maxqlen tsl ts2 MDR QueAdd EndDomainDefine In the above format bold words are keywords and italic words represent the words that should be replaced by the user with appropriate settings Multiple RuleAdd and QueAdd lines can exist in a DS domain definit
176. elf with the same dispatcher program After this is done one can run up all coordinator programs on their respective emulation machines and the GUI program on the emulation machine with the IP address 192 168 1 1 Recall that the Dispatcher IP address should be correctly specified in the panel Menu gt G_ setting gt Dispatcher After setting up the network topology and the traffic one then double clicks the icon of the virtual router to pop up its dialog box In this example one should enable the first option Use a real router to connect multiple emulation machines because the virtual router represents a real router The detailed settings for this panel on the two virtual routers are shown below The first figure shows the dialog box of the virtual router connecting the 1 0 1 0 24 and 1 0 2 0 24 subnets and the second figure shows the dialog box of the virtual router connecting the 1 0 2 0 24 and 1 0 3 0 24 subnets Notice port 2 in the dialog box of the left virtual router and port 1 in the dialog box of the right virtual router They both connect to the middle part Because the coordinator running on the middle emulation machine uses 192 168 2 1 to register itself with the dispatcher which is the interface that is closest to the left emulation machine where the dispatcher is running both of their Coordinator IP address should be set to 192 168 2 1 Regarding Emulation Machine IP address the settings for
177. enna and channel model parameter setting column One can set the values of antenna related and channel model related parameters in this column e g the operating frequency the antenna height and the transmitting power etc Channel Model Selection On the top right of the dialog box is the channel model selection column One can choose the signal propagation channel model that will be used in the simulation in this column NCTUns categorizes the supported channel models into two classes One is the Theoretical Channel Model class which collects the channel models that are developed using theoretical formulas In this class one should first select the path loss model that is intended to be used in the simulation and then can optionally select a collaborative fading model to more realistically simulate the fading effect 80 w Epecity physical layer and choneel model parsaeters Foppa Chane Pied amp Theoretical Channel Model Path Lowe Hudi E Teika Ground Peang Miga fe Mont leek Ferpirical Charmed Haiei Tuantemnabeignk re Syberia Mode Commectinaty ipis TransPeaver iaar Mm Use th Erenernithing Mode Garett Line the merei node perspective Averspetiulingieght nn Shreetaiath re AverageBukdngiietance ern Plat ial era operant Anba Gain Pathe amd Cantey Shandand aviation arii rei Currently NCTUns supports three theoretical path loss models which are listed as follows in sequence Fre
178. ent and need not be the case In 4 the authors proposed an approach to reducing an OBS switch s packet loss rate In this approach when the desired transmission times of two contending bursts overlap partially one burst is chosen to be switched in its entirety while the other burst is allowed to be partially switched with the overlapping part being truncated Two different truncation schemes can be used The first scheme is to cut the head of the second burst while the second scheme is to cut the tail of the first burst They have different effects and require different protocols and processing In 5 the author proposed an approach to using TCP congestion control scheme to significantly reduce the packet drop rate in an OBS network In NCTUns to create an OBS network a user just uses the optical burst switch tool button to add several OBS switches into the network and use the link tool button to connect them Like in a circuit switching optical network optical edge routers must sit at the boundary of the OBS network to connect the OBS network with the outside non optical fixed network The following figure shows an example OBS network in NCTUns In an OBS network simulation case unlike in a circuit switching optical network simulation case a user need not set up protection rings and specify the light paths between every pair of optical edge routers This is because these schemes are not the focuses of the current OBS r
179. ent is started gt Field 4 lt duration unit tick of this event gt Field 5 lt packet type gt DATA 802 3 802 11 Data packet RTS 802 11 RequestToSend packet E More information about the get set command can be found in The Protocol Developer Manual for the NCTUns 6 0 Network Simulator and Emulator Running the simulation Several commands are provided to control the execution of simulation cases They are located in Menu gt Simulation Pause Continue stop Abort Reconnect b Disconnect oubmit as Background Job Run Pause Continue Stop Abort After a user switches to the Run Simulation mode the user can start running the simulation by executing the Run command in this group During simulation the user can use the Pause Continue Stop and Abort commands to pause continue stop and abort the simulation The difference between the Stop and Abort commands is that the former command will return the current simulation results to the GUI program while the latter command will not Reconnect Disconnect A user can disconnect the GUI from a currently running simulation job Doing this allows him her to quit the GUI program and switch to do other things The user can come back later restart the GUI program and then reconnect to the disconnected simulation job Submit as Background Job A user can directly submit a simulation job
180. er e nn if Pl tl annee Noa Pasa Sat Frat EA iama ram if E i E 5 se eg N NATNR za v ps Mig kti S Ot eer ee eTa TA r ee ke oa bot RE At SA ee tr od ck SVR EK We ae ei AY a ae a i 5 T D NPN a ee A e Ba A ER ea gl k aran VENE AT NR p BOK NONIN FB PRX I PRIS eS pZ N AONTA i pes a ies i A P e ba i e ER Fac t j r3 RFRA i YA Poses Ai 5 W al m F _ St QO OD I ss se oea TET AA db E Hfr g rai m Pa haie P te Subnet To quickly expand a simple network topology a user can choose the subnet function on the tool bar and then click on the working area to insert a group of hosts The group of added hosts are all connected to a switch When the subnet dialog box appears a user can enter the desired number of hosts and the desired subnet radius The following figure shows the subnet dialog box ee Ct toe b Toae er Satie Beton Poe Se Aeon tA le ea eee vaeaw Ps Eig eee aiipae jf jee EE I r 3 LALLaS A LaaLaly sa bese BeGESBStr BEY ARRAS Eee DERP af md DO Bot al 4 gt ll abi Fee File manipulations Several commands are provided to manipulate files They are located in Menu gt File New Executing this command will close the current simulation case and clear the working area for a new case Open Reload an already existing case The tpl file of the desired case should be selected to open the case Save Save the current simulation case s topology and node co
181. er of total deployed car on the road the dialog box for specifying the interfaces of an ITS car will be popped up One can specify which types of and how many radio interfaces that he she intends to add into the deployed ITS cars Note that the actual number of deployed cars may be smaller than the specified maximum number due to the deployment density limitation vV Select the interfaces that this ITS car is to be equipped with interface list J 802 11 a infrastructure mode interface 802 11 a ad hoc mode interface Cancel _ 80211 b infrastructure mode interface _ 802 11 b ad hoc mode interface 802 11 p OBI _ GPRS radio DVB RCST Return Channel Satellite Termina 802 1 amp e mobile station Specify Multi interface ITS Cars In the following we show how to set up an ITS car One can invoke the dialog box of an ITS car by double clicking its icon in the field Similar to that of a multi interface mobile node the dialog box of an ITS car comprises two tabs Application and Interface The functions on these tabs for an ITS car are similar to those for a multi interface mobile node In the section we only highlight the notable settings for an ITS car As shown as follows for each ITS car the GUI automati cally enters a fixed command Car Agent into the Appli cation tab which will launch the default car agent program during simulation The Car Agent program is responsible for
182. er will then start playing the recorded packet animation The following figure shows these control buttons AQA MPi m ph The following figure shows the animation player when it is playing a packet animation trace file BR BARBER Bessa Tees i am T SA F Au Ja sue Senn SMILLALLASL SE LLELLE ea aa Bie BERBER SHE ESF RAUT ARASRD Se DERP 1 6 A iP le a While the packet animation player is running the user can also launch the performance monitor In this way the perfor mance monitor will dynamically plot performance curves of some logged performance metrics as the time is progressing For example a TCP connection s achieved throughput or a link s utilization can be plotted The time used by the perfor mance monitor and the packet animation player are synchro nized with each other The following figure shows the performance monitor when it is plotting a performance curve over time 17 W froot 6 Orel ease DemoQe_TwoTCPContend Demote_TwoTCPContend t Q x File Window Color Option Graph Title 1430 1267 1144 100l 858 1135 INF 429 266 143 The performance plotter is plotting a performance curve over time Note that the performance monitor can also be used to plot static performance graphs i e the performance curves during a fixed time interval and this can be easily done When the packet animation player is not playing e stopped the user can directly move
183. erencing of groups The support includes traffic source identification audio video gateways multicast to unicast translators and other functions Traffic receivers can use RTCP to send quality of service feedback to the multicast group so that the traffic source s sending rate can be adjusted according to the current available bandwidth RTCP also supports the synchronization of different media streams SDP is intended for describing multimedia sessions for the purposes of session announcement session invitation and other forms of multimedia session initiation It provides a format for describing session information to session partici pants Such information includes session level parameters and media level parameters Session level parameters may include the name of the session and media level parameters may include the media type and format Because SDP provides only session descriptions and does not provide a way for transporting or announcing sessions it needs to be used with other protocols such as the session initi ation protocol SIP SIP is a signaling protocol that handles the setup modification and the tear down of multimedia sessions A common usage is that SIP contains SDP infor mation within its message to set up or tear down multimedia sessions 90 This chapter only gives a brief introduction to these protocols More detailed information about RTP and RTCP can be found in 1 2 more information about SDP can be f
184. ernet A user can execute the Menu gt G_Tools gt Generate Large Internet like Network command to specify the parameters of the large network to be generated In the parameter dialog box the Node Number field specifies the number of nodes of the network to be generated This number cannot be too small Otherwise the generated topology will not share the same properties with the Internet topology Links in the generated network are classified into three different categories and each category can use a different bandwidth These categories are the core edge and LAN links respectively The unit of bandwidth in this dialog box is Mbps The Max X and Max Y fields specify the length and width of the field over which the generated network will be laid Their default values are taken from the simulation case s field sizes which can be configured in Menu gt G_Setting gt Simulation Each node in the generated topology will be placed on the field according to their generated x y locations The signal propagation delay of a link between two nodes will be automatically calculated and set It is the distance between these two nodes divided by the light speed fee be Oto flere G Sey ey eee ee ie ixXA eo VER Dw Rea Ae Ae ea Pg aaa Fr 1 jes aonn er rey4yWILLGLLai SA ASALS JF aa ee ke Bee ees ee EA 440 85 gt BDERP a AWA JAE CNF ENSE a M F k Xi Fi NER ROSEN SES SSS AY JAZ ts ye Ey ba
185. ersistence One can delete a service information entry by clicking the Delete button The following is an example to delete a service information entry IEEE 802 11 p RSU IEEE 802 11 p Provider Setting Application Mobile IP Node ID Provider Service Information Table 1 1 1 000000 Add Add The functions of the Application and Mobile IP tabs of an 802 11 p RSU are the same as those of an 802 11 b infra structure mode mobile node To save space we do not explain them here One can refer to previous chapters for their usages The dialog box for setting the attributes of an IEEE 802 11 p OBU is shown in the following figure which comprises six tabs 1 IEEE 802 11 p Provider Setting 2 IEEE 802 11 p User Setting 3 Application 4 Path for Testing 5 Down Time and 6 Mobile IP 144 In an 802 11 p network an OBU is allowed to provide services for other OBUs and subscribe to services provided by other OBUs or RSUs To provide services for other OBUs one can specify the IEEE 802 11 p Provider Setting tab Because the functions of the IEEE 802 11 p Provider Setting tab is the same as those in the dialog box of an 802 11 p RSU we do not explain them again here Under the IEEE 802 11 p User Setting tab one can specify when and to which service provider by specifying the ID of the service an 802 11 p OBU intends to subscribe during simulation Clicking the
186. es Both of these files contain important installation information The RELEASE NOTE file contains notes relevant to each release of NCTUns These notes point out the new functions bug fixes performance and GUI improvements data structure and program changes etc between the current and the previous releases The FAQ file answers technical questions that may result due to an incorrect installation The KNOWN PROBLEM file lists some known system problems For example if a computer is equipped with a very new video card the new video card driver may not work well with Fedora 11 A user then runs the install sh shell script This script will install the pre compiled Linux kernel image patched for NCTUns It will also build all executable programs and copy them to their default subdirectories In addition it will create 4 096 this number can be easily increased tunnel special files tunnel interfaces in dev These steps may take some time During the installation the user should carefully watch out whether some error messages are generated If any serious error message is generated the installation may fail After the installation is successfully finished the machine must be rebooted and then the user must choose the NCTUns kernel to boot After the machine boots up with the NCTUns kernel the whole installation can be considered successful Before start running NCTUns to conduct simulations the user should carefully read th
187. es array m Top left position X 80 Y 180 multi interface mobile nodes Dimension Row Column l Node spacing Specify Multi interface Mobile Nodes In the following we show how to set up a multi interface mobile node The dialog box of a multi interface mobile node will be popped up after one double clicks a multi interface mobile node icon Under the Application tab one can specify the application programs that will be executed on this multi interface mobile node during simulation lulti interface pplication Path Interface Input file Name Start time s Stop time s Command Modify Delete App Usage Cancel Under the Path tab one can specify the moving path of this multi interface mobile node The following figure shows an example path setting Another method to specify the moving path is to use the mouse to click drag click to graphically specify the moving path in the working area This operation is exactly the same as that for specifying the moving path for a single interface mobile node Rs flulti interface Mobile Application Path Interface ID Xim Yim Arrival time s Pause tim i 0 268 00 1 453 130 00 0 21 174040 Modify 12 819363 000000 327 000000 543 000000 67 0325889 Delete 93 409546 Ki l 19 i i 65
188. es not denote the ID of the original source subnet of the packet but rather the ID of the last subnet on which the packet traverses before it is sent to this real router and destined to a subnet of 1 0 X Y For example the first route command will make the real router forward packets generated from the 1 0 1 0 24 subnet and destined to the 1 0 2 0 24 subnet to the real machine with the IP address 192 168 2 1 which is designated to emulate the subnet of 1 0 2 0 24 71 The setting of routes for this example is more complex than that used in the previous two examples In this example case the emulation machine in the middle needs to forward packets for other emulation machines However in the previous two example cases this is unnecessary For example a packet from the host 1 0 1 1 to the host 1 0 3 1 needs to go through the subnet 1 0 2 0 24 to arrive its desti nation node 1 0 3 1 This packet not only needs to be forwarded by the two real routers but also needs to be forwarded by the emulation machine in the middle One then runs up the dispatcher program on the emulation machine 192 168 1 1 and properly modifies the coordi nator cfg file for each involved coordinator program Because the dispatcher program is run on the emulation machine with the IP address 192 168 1 1 one should modify the DISPATCHER_IP from 127 0 0 1 to 192 168 1 1 for each involved coordinator program so that each coordinator program can register its
189. es to these ports one to one These physical links are correspondingly represented as links in the simulated network whose bandwidths and delays are specified in and simulated by the simulation machine As in previous emulation cases once real world 60 Fis Edi g Toole H Tose G fameg H Getting Gprwision yew jap PIYE EICELENT CALTE gweY sia jlo SBORBBIF rT VUILLGALLGILS ALALLSS Sa he io BeSeBSMSer BREA ARARA a DERP 1 a stcpl i rtcpl g Fi rtepz stepa packets enter the simulated network they need to traverse simulated links and subject to the bandwidth and delay of these simulated links Che Sos GB Tuis N Tak amp wt Gg Kh wg Gde Yow lbp lve wea segweeywvvuwp p we a 4 GALA 2S TSA RG ARATE A DERP vi o SOUNN VeSGkeereet he BH LINKL LINK3 Simulation Machine External Router The simulation engine needs some information about the external router Thus the user needs to provide some infor mation in an external router s GUI dialog box which is shown below For each port of the external router in the real world the user needs to provide the association among the following information entities its assigned IP address in the simulated network this information is automatically provided by the GUI in the second column of this association table after the port ID column the real IP address of the network interface on the simulation machine that connects to this port via a link
190. ese application programs now may use wrong IP addresses to communicate with their intended partners 2 Move the mouse cursor to the tool bar which is shown below AXAS CCUSAE SOR ORCVAv sus eeees joe jes BOMB rrr sULLaLL aS isALae sabe ke BOBRBMESS BBR AQRRRealDERP 3 Left click the router icon on the toolbar 4 Left click somewhere in the blank working area to add a router to the current network topology which is empty now 5 Left click the host icon on the toolbar Like in step 4 add three hosts to the current network topology The resulting topology is shown below Das Part G Tens h coe j Beery ii beig Geer fee riep e e rE eR C EENET TTT EELEE CLE BOB Bir rc 4M LLALL GLa aaa La ea BewEBEEHRSEes ABR 12 685 2 0 ERP s w a 5 El een eth 4 0 00 00 0 A Ss on om Bawi tems D E 6 Now we want to add links between the hosts and the router Left click the link icon on the toolbar to select it 7 Left click a host and hold the mouse button Drag this link to the router and then release the mouse left button on top of the router Now a link between the selected host and the router has been created 8 Add the other two links in the same way Now the simple network topology has been created a jea a Say TITEI eT Ty hand eek ee ee BOR r r 49 RB LLGALLa La ALAA Sabre io BPeRBERREtS BER AAAA Se OERP ws i F 0 000 000 00 OD as we A i I he m 9 Remember to save this n
191. esearches When packets need to be sent from an optical edge router to 112 another optical edge router NCTUns OBS protocol modules will automatically choose the shortest path between them as their light path ixAwvw oo VaR w SS enV U Uw gp wk de ee a T yla A e ai SALSA LA TSR Ee i OO Pe eR eessa Pah D ERP AS SS VL X ZAAN lt fa A AUH j m H An example optical burst switching network OBS Protocol Stack In the following we show the protocol stack of an optical burst switch and the protocol stack of an optical edge router in an OBS network In this OBS network an optical link has three wavelength channels In the following we show the parameter dialog box of the protocol module OPT_OBSW used inside the protocol stack of an optical burst switch This protocol module deals with two things First when multiple control packets arrive exactly at the same time and they all contend for the same outgoing channel it needs to decide which one to accept while discarding other ones because the optical burst switch can process only one control packet at one time At present three contention resolution methods are provided In the first method the module randomly picks one control packet In the second method the module picks the control packet with the smallest time offset while in the third method the module picks the control packet with the largest time offset Second when two bursts contend and overlap with each o
192. esh Mode Gateway S55 BAIS d Mode Host S553 Mesh IEEE 802 16 d Mesh Network Protocol Stack The settings of IEEE 802 16 d related modules can be specified via the Node Editor The following figure shows the default protocol stack of a mesh BS node By double clicking on a module icon its corresponding parameter dialog box will be popped up For example one can specify the maximum MAC layer transmission queue length in the parameter dialog box of the MAC802_16_MeshBS module As for the physical layer settings parameters such as the default channel ID and the receive sensitivity can be specified in the OFDM_Mesh module s parameter dialog box IEEE 802 16 d PMP Mode Concept The IEEE 802 16 d PMP mode is a last mile technology to replace traditional wired solutions The downlink from the base station BS node to subscriber station SS nodes operates on a PMP basis On the other hand the uplink is shared by all SS nodes In this mode traffic from a SS node to the Internet or between two SS nodes must be routed through the PMP BS node The PMP BS node Ao is responsible for allocating network resources and coordinating uplink transmissions As in the IEEE 802 16 d mesh network described previ 154 ously in NCTUns the PMP SS node is subdivided into two types the PMP gateway SS and the PMP host SS nodes A PMP gateway SS node fg can perform the self configu ration and routing functions Besides
193. ession bandwidth Session active time from fo sec Media type Destination port number Payload type Encoding name Sampling rate HZ Bits per sample Audio packet time ms Video frame rate F sec os a omes The SDP dialog box An Example We use an example to illustrate the uses of RTP RTCP and SDP in NCTUns In the following figure host1 and host2 are both a RTP sender and receiver while host3 is only a RTP receiver That is host sends RTP packets to both host2 and host3 host2 sends RTP packets to both host1 and host3 but host3 does not send any RTP packets to host1 and host2 The packet loss rate configured on WAN for the direction from host 1 to host 2 and host 3 is 10 while the packet loss rate configured on WAN for the reverse direction is 5 The RTP programs run on host1 host2 and host3 use RTCP to report the measured 1 round trip time RTT of packets 92 2 delay jitter of packets 3 loss rate of packets and 4 cumulative number of lost packets between a pair of hosts These information are generated by these RTP programs and saved into log files with the following names IP i IP j IP k delay IP i IP j IP k jitter IP IP j IP k pktlossrate IP 1 IPG IP k pktlost respectively In the above filename IP i IP G IP k IPG IPG and IP k will be replaced with the IP address of host i host and host k in the simulated network respectively This fi
194. etwork topology by choosing Menu gt File gt Save As For this simple case we will save the topology file as test tpl When the GUI program creates test tpl it also creates test xtpl This file stores the attribute values stored in test tpl in an XTML 10 like text format This allows a user to easily view and check the stored attribute values F9 Application Flces Sptem e qi i ACTORS 6 0 Waren 9 1 203 Bie Ede Q Tools N Tools Q Selling N Seting Simutation Yew Hele Hew Le i a seyvyyvww Pg eae euws jae j is alia LL4a CAMP ALALVS FSi Peis BOREOL DERP Save Aa Pravel fo Fia Opetaing Mae Background Job Management Cw I Momoa 6 A I piri E E ohia E rcote locathost hai ACT Lins 6 0 versace S It is not mandatory to save the network topology into a file in this mode A user can save it in the Edit Property mode Depending on in which mode a network topology file was saved when the file is opened again its current mode will be automatically set to the mode when it was saved Editing Nodes Properties A network node device may have many parameters to set For example we may want to set the maximum queue length of a FIFO queue used inside a network interface For another example we may want to specify that some application programs traffic generators should be run up on some hosts or routers to generate network traffic Before a
195. everal commands are provided in the Edit command menu for various types of networks 24 ie pdi G Tai H Toos 0 Saeg H me Ein m y a Aro cU SRE ease sev avwa pg ae eug i a LEI l Fr FHL LALLA SALSA Aa Ysa eee BeSESRBEt BER ARREARS SDERP Ge Ge af j aj 4 z ma a i A 0 OO a TO AA I om oS hemp HP j A group of nodes can be selected Editing the Attribute of Nodes After nodes are added a user can enter the Edit Property mode to set the detailed attributes of any node by double clicking its icon Several attributes and functions such as Application Down Time and Command Console are provided for many kinds of devices see the following host dialog box Therefore we present their usages here Under the Application tab a user can specify which appli cation program should be run on this node He she can put the command string into the command field In addition to the command string the start time stop time and argument of the specified program can also be set After an entry is added the user can use the Modify button to modify the entry or use the Delete button to delete that entry The Add RTP and Modify RTP buttons are for RTP simula tions They will be explained in a later chapter specific to RTP The following shows the popped up dialog box after the Add button is pressed If the application program needs to read a configuration file when it is execut
196. eway switch is needed to connect these two networks The following figure shows a configuration of an OSPF WMN In this network the four mesh access points at the corners of the WMN connect to the fixed network on the right via a mesh multi gateway switch With this configuration a client station in the WMN can exchange its packets with any host on the fixed network A WMN need not connect to a fixed network and can be a closed network by itself In such a configuration a client station cannot access information provided on the fixed network However client stations can exchange their infor mation via the WMN For example they can make voice over IP phone calls among themselves on top of the WMN 115 fee bor DFs B Foin ji mry y bemmy Gea y Ha XAeoVUER ED OSS TALT EE E se ia rere yw Loki at SALA Looe E AQ aad aD ERP nO beth ere r Se errs Ma P a Hi Mal Ii E phj apers J Setting Up Wireless Mesh Networks In the following we show how to set up a wireless mesh network Insert Mesh Access Points A user can click one of the two mesh access point icons and place mesh access points in the working area one by one In addition a user can quickly insert multiple mesh access points by using the Menu gt N_ Tools gt 802 11 b Wireless Mesh Network gt Insert 802 11 b Mesh Access Points command In the popped up insertion dialog box shown below a user can choose which type of mesh access point should be
197. f other nodes signals However only when the receiving station is within the transmission range of the sending node will the packets be guaranteed to reach the receiving station successfully 49 e An IEEE 802 11 b data frame is depicted by an arrow with a DATA annotation e An IEEE 802 11 b acknowledgement packet is depicted by an arrow with an ACK annotation Summary This chapter presents the Packet Animation Player capability of the GUI program In this chapter relevant options are covered In addition both wired and wireless packet animation effects are illustrated and explained 50 6 Performance Monitor p monitor a links utilization or a TCP connection s achieved erformance monitor is a generous purpose and useful tool that can graphically display plots of performance metrics For example it can help users throughput This chapter gives an overview of the functions provided by the performance monitor Running the Performance Monitor A user can execute the Menu gt G_Tools gt Plot Graph command to launch the performance monitor The following figure shows the window of the performance monitor Eile Window Color Option We E 132 O T 2 28 a time From the performance monitor PM window a user can execute the PM Menu gt File gt Open command to select a desired log file to open The user can then left click the start icon J gt of the time bar at th
198. face mobile node external WLAN ad hoc mode mobile node for emulation purposes and external WLAN infrastructure mode mobile node for emulation purposes a GPRS phone an 802 11 e WLAN infrastructure mode mobile node a 802 16 e mobile station MS a DVB RCST Return Channel Satellite Terminal RCST or an 802 11 p On Board Unit OBU To specify the moving path of such a node a user first selects Ri on the tool bar He she then clicks the mobile node and start dragging and clicking the the moving path tool icon mouse s left button repeatedly to construct the whole moving path This operation continues until the user clicks the mouse s right button Note that for an ITS OBU e a car its moving path is dynamically determined during simulation rather than be specified before simulation A moving path is composed of a sequence of turning points and segments After a moving path is constructed any of its turning points can be easily moved by the mouse to any place to adjust the shape of the path Each turning point is repre sented by a grey dashed square box and contains the X loc Y loc arrival time pause time moving speed to the next point information This information can be changed by double clicking the box in the Edit Property mode Suppose that a user wants to change the location of a turning point he she can click the mouse s left button on the box hold it and then drag it to any place When a mobile
199. forward packets originated from the simulated network to the external host In addition to the above information the user needs to enter the IP address used by the simulation machine in the real world The assigned host IP address is the IP address assigned to this external host in the simulated network If a node in the simulated network wants to actively send packets to the external host the node can use the external host s assigned IP address as these packets destination IP addresses These packets will then traverse the simulated network and reach 56 w Simulation oo O Simulation Speed Real Time GUI GDB De gt One tick nanoseco Simulation Speed As fast as possible As fast as the real world clack This speed must be selected for an emulal However it can also be used for a simulatic OK Cancel the external host in the simulated network With the IP address mapping specified here the emulation kernel module will intercept these packets and then forward them to the external host in the real world External Host Host ID 1 Assigned host IP address in the simulated network PONRI External host s real IP address AAE i Simulation machine s IP address External routing table for Linux for FreeBSD Example Suppose that the simulation machine s IP address is 10 0 0 1 and the external machine s IP address is 10 0 0 2 Then the external host IP address field should b
200. fra structure Mode o OK Cancel The dialog box of the Insert WLAN Mobile Nodes command Import Export Mobile Nodes and Their Paths from to File These two commands are located in the Menu gt G_ Tools menu The import function loads all mobile nodes and their moving paths from a mdt file while the export function saves the same information into a mdt file It s convenient and useful for a user to save mobile nodes moving paths to a file and later reload and reuse them For example to compare the relative performance of several mobile ad hoc network MANET routing protocols under the same moving pattern the user can 1 create a simulation case in which mobile nodes move in a desired pattern 2 export these mobile nodes and their moving paths to a mdt file 3 create a new simulation case for studying the perfor mance of a different routing protocol 4 import the same mdt file in each of these simulation case and 5 use the Node Editor button in the dialog box of a mobile node to use the desired routing protocol module 6 use the C P S T A N button to replace the parameter values including the protocol stacks of all other mobile nodes with this one 7 finally run the new simulation case and obtains the performance results of the different routing protocol under the same network topology and configuration The format of the mdt file is simple and explained in the file itself A user can first exp
201. g all of these coordinator programs one can run up the GUI program on the emulation machine with the IP address 192 168 1 1 and set up the Dispatcher IP address in Menu gt G_setting gt Dispatcher One then draws the topology of the emulated network using the GUI and sets up the application programs to be run during the emulation In this example the commands to run the TCP application programs are listed below The command stcp p 8000 1 0 2 1 is run on the host 1 0 1 1 and the command rtcp p 8000 is run on the host 1 0 2 1 The command stcp p 9000 1 0 3 1 is run on the host 1 0 2 2 and the command rtcp p 9000 is run on the host 1 0 3 1 After setting up the traffic one should double click the icon of the virtual router to pop up its dialog box In this dialog box one should enable the first option Use a real router to connect multiple emulation machines The detailed setting on the panel is shown as follows After setting up the whole emulation case one can switch the GUI to the Run Simulation mode and start the simulation Use a direct link to connect two emulation machines An alternative to connect the three emulation machines is to connect them using a layer 2 switch In such a physical network configuration the virtual router does not correspond to any real device in the real world As shown in the 69 Virtual Router External Router ID i Use a r
202. gt Get 46 Add a New Module to the NCTUns After a user has developed his her own module two tasks must be done to integrate the new module into the NCTUns The first task 1s to introduce the new module to the node editor so that it can appear in an appropriate module group and its parameter dialog box can be shown when it is double clicked in the middle working area The second task is to register the new module with the simulation engine so that its code is executed when a simulation case using the new module is executed Add a New Module to the Node Editor To let the node editor know that a new module has been added to it the user must add and place the definition of the module into the module description file mdf cfg To under stand the detailed format and meanings of the module description file readers should refer to that file stored in usr local nctuns etc and The Protocol Developer Manual for the NCTUns 6 0 Network Simulator and Emulator Register a New Module with the Simulation Engine To let the simulation engine find the code of the new module and successfully execute it the user must also register the module code with the simulation engine NCTUns provides a simple method for a user to register a new module with the simulation engine Detailed procedures are documented in the The Protocol Developer Manual for the NCTUns 6 0 Network Simulator and Emulator Summary In this chapter we present th
203. h more than 1 Gbps bandwidth links The speed of the simulation engine can be set to As fast as possible or As fast as the real world clock Normally a user would want a simulation case to be finished as soon as possible However when NCTUns is turned into an emulator or the user conducts a human in the loop tactical mobile ad hoc network simulation the speed of the simulation engine should be set to As fast as the real world clock This option is also useful when a user wants to use the command console during a simulation The following figure shows the dialog box of the speed tab Simulation u G Simulation Speed Real Time GUI GDB De One tick Simulation Speed Px NAaAnosecol C As fast as possible As fast as the real world clock This speed must be selected for an emulal However it can also be used for a simulatic Cancel Under the Real Time tab two GUI display options for military tactical mobile ad hoc network MANET simulation can be specified In general MANET simulation cases each mobile node s moving path is pre specified before the simulation is started In contrast in military tactical MANET simulation cases or Intelligent Transpor tation Systems simulation cases mobile nodes moving paths are dynamically generated by agent programs running on mobile nodes during simulation To allow such type of simulations the option Dynamic moving path generation during s
204. h only a few simplified packet processing capabilities Instead the simulated network can be a large network composed of a large number of nodes and links Actually this simulated network although used in an emulation can be as complex as any network that can be simulated by NCTUns NCTUns uses a novel kernel reentering simulation method ology so that simulated nodes can run real world applica tions and use the real world Linux TCP IP protocol stack to exchange packets Due to this property in a NCTUns simulation realistic traffic flows generated by real world applications and TCP IP protocol stack can be set up among nodes in the simulated network When such a simulated network is purposely run in real time for brevity such a simulated network is called the emulated network in this chapter real world devices can exchange their packets over the emulated network These real world packets can 63 encounter the background traffic e g HTTP TCP traffic generated inside the emulated network to experience more realistic network conditions caused by these traffic Beside allowing two real world devices to exchange their packets over an emulated network in a NCTUns emulation the application running on a real world device can set up real TCP UDP connections with a real world application running on a node in the emulated network This unique capability can save the number of real world devices that need to be used in an emulat
205. han these ideal numbers due to poor channel quality and inade quate time slots allocated to GPRS traffic GPRS Network Architecture A GPRS network is composed of GPRS phones MS GPRS base stations BS serving GPRS support nodes SGSN and gateway GPRS support nodes GGSN SGSN in GPRS is equivalent to Mobile Switching Center MSC in GSM networks GGSN provides interworking between a GPRS network and an external packet switched network such as the Internet SGSN is connected with GGSN via an IP based GPRS backbone network The architecture of a GPRS network is depicted in the following figure Internet GPRS network architecture GPRS Protocol Stack The protocol stacks used in GPRS devices are depicted in the following figure The full names of these protocols are described as follows SNDCP SubNetwork Dependent Convergence LLC Logical Link Control RLC Radio Link Control MAC Medium Access Control Radio Radio Physical Layer BSSGP BSS GPRS Protocol NS Network Service GTP GPRS Tunneling Protocol L2 is any layer 2 data link layer protocol such as Frame Relay or ATM Application Radio Radio MS GPRS protocol stack In NCTUns these protocols are implemented as protocol modules To understand the details of these protocols readers may reference 1 2 There are some differences between a real world GPRS network protocol stack implementation and a NCTUns GPRS network protocol stack implement
206. he Delete button is a general purpose button and can be used to delete a RTP or non RTP application entry More information about how to run RTP will be discussed in a later chapter e External Host Mobile Nodes and Router ae Assigned host IP address in the simulated network External host s real IP address Simulation machine s IP address External routing table for Linux for FreeBSD Example Suppose that the simulation machine s IP address is 10 0 0 1 and the external machine s IP address is 10 0 0 2 Then the external host IP address field should be filled with 10 0 0 2 Suppose that the external machine wants to make a tcp connection to a host in the simulated network whose IP address is 1 0 3 4 Then on the external machine one should first execute the following command to add the needed routing entry to the routing table Linux route add net 1 0 0 0 16 gw 10 0 0 1 FreeBSD route add 1 0 16 10 0 0 1 Node Editor OK Cancel An external host external mobile node ad hoc mode external mobile node infrastructure mode or external router represents a real device in the real world They are used for emulation purposes Because emulation is an important function a separate chapter titled Emulation is dedicated to it Explanations of the usage of these fields will be documented in detail in that chapter e Hub Node editor Cancel 28 Because every port of a hub mu
207. he optical edge router to edge router routing path tool button Rs to manually specify a routing light path between two optical edge routers The operation used to specify a light path is similar to that used to specify a protection ring The only difference is that a light path must start and end at two different optical edge routers while a protection ring must start and end at the same optical switch During the light path creation process a user can cancel the path by right clicking the mouse at any place A thick yellow line will be shown on the screen to indicate the current light path The following figure shows that a light path between two optical edge routers has been created The sequence of the selected switches determines the light path and it is very important If the light path needs to traverse over some protection rings it should follow the directions of these rings so that its traffic can be transported naturally on the working rings of these rings That is if a protection ring is clockwise the light path should also be clockwise on the ring This arrangement is the most efficient arrangement The following figure shows the correct arrangement of the light path assuming that the underlying protection rings are clockwise fee fe Ott E Tam D Bg ee Gee ee fee tBAwe B4 8 5 a RSkR BARRE S BESS Cee i ise E EEN Fre JA LLALLA LE LE1L LS a eae BERR OR Eee BET AS e345 DER FP bi oo oe aA A 4 b li E 2 g a 1TH 2E
208. he GOD routing module A higher frequency allows the GOD routing module to respond to link failures more quickly but at the cost of generating a larger file to store more information Summary The topology editor provides users with a friendly and easy to use working environment In this environment a user can quickly build network topologies and specify application programs Executing and controlling simulations can also be easily done in this environment 4 Node Editor he node editor provides a convenient environment for a user to flexibly configure the protocol modules used inside a network node By using this tool a user can easily add delete or replace a module with his her own module to test the performance of a new protocol Protocol Module Concept A protocol module implements a particular protocol such as ARP or a particular function such as the FIFO packet sched uling discipline In the node editor all modules that are grouped in the same module group displayed at the top of the node editor share similar properties For example in the 802 11 MAC group we may have one module called 802 11IMAC while another one called my802 11 MAC having NCTUns provides several pre developed protocol modules Users can add new protocol modules to the node editor or replace some existing modules with his her own ones For example in the PSBM packet scheduling and buffer management module group four modules
209. he PMP BS node only supports unsolicited grant service UGS flows One can double click the icon of a PMP BS node to invoke its dialog box shown in the following Then he she can specify the sustained rate in Kbps allocated for each PMP SS node ss List SS Node E 1 ID Sustained Rate Kbps LOTO IEEE 802 16 d PMP Network Protocol Stack Currently there are no GUI adjustable parameters for PMP related modules If a user wants to change the default parameter values used inside a PMP related module he she can modify the source code of the module which is included in the NCTUns package and re compile the NCTUns simulation engine program Summary In this chapter we present an conceptual introduction to IEEE 802 16 d networks and the necessary steps for simulating these networks over NCTUns Also we explain the usages of important commands and dialog boxes to help users simulate such networks correctly 22 IEEE 802 16 e WiMAX Networks The IEEE 802 16 e specification defines a novel next generation broadband mobile wireless access network which amends the IEEE 802 16 d standard released in year 2004 The 802 16 e differs from the 802 16 d in two aspects First the 802 16 e adopts the Orthogonal Frequency Division Multiple Access OFDMA technology to manage link bandwidth while the 802 16 d uses the Orthogonal Frequency Division Multiplexing OFDM to do it Second the 802 16
210. he icon of a module inside the node editor the dialog box for the module will be popped up For example to specify the physical layer parameters such as the channel ID operating frequency transmission power and the sensitivity for received signals one can double click the OFDMA_ module icon to invoke its dialog box which is shown as follows Module Edit Parameters Setting Channel ID i Frequency MHz 2300 Cancel Transmission Power dbm 2 Receive Sensitivity dpm 99 Setting of Physical Layer Parameters for IEEE 802 16 j Transparent Mode Nodes The above figure shows the default settings of the physical layer parameters for an IEEE 802 160 node One may need to change the default values of these parameters e g the Channel ID parameter based on the simulated network topology According to the 802 160 standard the communications among all the transparent mode stations within the same cell should take place on the same channel Therefore one must make sure that the used channel IDs of the T RSs and T MSs are set to the Channel ID used by the TMR BS Also the user may need to adjust the transmit power of the 802 16 j nodes to construct a specific network case In practice the transmit power of a TMR BS is usually set to a value higher than those of T RSs and T MSs IEEE 802 16 j Non Transparent Mode Concept An IEEE 802 16 j non transparent mode network differs grealy from an 802 16 j transparent mode
211. he user uses the single machine mode of NCTUns he she needs to run up the dispatcher and coordinator programs first The following procedure assumes that the user uses the single machine mode If the user uses a simulation service center running in the multi machine mode that is already set up by some person or institute he she can skip the following two steps l Run the dispatcher program located in usr local nctuns bin The default values of the parameters needed by this program is stored in usr local nctuns etc dispatcher cfg 2 Run the coordinator program located in usr local nctuns bin The default values of the parameters needed by this program is stored in usr local nctuns etc coordinator cfg Now the user needs to let the GUI program know the IP address and port number used by the dispatcher The user should configure these settings by invoking the Menu gt G_Setting gt Dispatcher command The following figure shows the popped up dialog box The default port number is 9 800 If the user is using the single machine mode the IP address can be specified as 127 0 0 1 which is the default IP address that the UNIX system automatically assigns to the loopback interface The user name and password must be valid For the single machine mode it is the user s account on this local machine For the multi machine mode it is the user s account on the chosen remote simulation machine Note that in the mu
212. hen the mobile host leaves its home network and moves to a foreign subnet or when it moves from an old foreign network into a new foreign network Readers should refer to relevant RFCs to get more infor mation about Mobile IP A Mobile IP Usage Example The following figure shows a Mobile IP usage example In this network there are three different wireless subnets located at the bottom Each wireless subnet uses an EEE 802 11 b access point to allow mobile hosts to get connected to the fixed network Of course making a connection is possible only if these mobile hosts are within the coverage area of the access point In this example initially the infrastructure mode mobile host is in its home network which is the wireless subnet on the left A greedy TCP connection is created between it and the correspondent host at the top Then it leaves its home subnet and moves toward the right access point On its way it will enter the wireless coverage area of the middle wireless subnet and then that of the right wireless subnet Then it will come back and return to its home network With Mobile IP the TCP connection can be kept alive continuously even though the mobile host has entered a different subnet with a different network number 74 eae TE aai O Tms pi Teme D Erg fae Eee j ee eee ST eee ee ae ee aa Me M BEB Birr ei7WILLo ki Se SLA Se ee ho Bee SEP BER AAS as SiO eR P i Immuno Te St a fee Se A
213. herefore receive different treatments Node Editor MAC8023 T MAC8023 T Ao Select Mode A WAN module exists in each port of a WAN node The WAN module can purposely delay drop reorder its port s outgoing packets Inside the parameter dialog box of the WAN module packet delaying dropping and reordering function can be indepen dently used Supported distributions include constant uniform and normal distributions The following figure shows the dialog box of the WAN module exponential Loss Rate 1 X Set Packet Reordering Time Distribution X Set Packet Delay Time Distribution Reordering Rate 1 Delay time distribution Reordering delay time distribution Constant Constant const value 1 const value 1 ms Uniform J Uniform min 1 min 1 ms max 5 max 5 ms Exponential Exponential min 1 min 1 ms mean 3 mean 3 ms max 5 max 5 ms _ Normal J Normal mean 0 mean 0 ms variance 1 variance 1 OK Cancel The parameter dialog box of the WAN module 31 Other methods to add Mobile Nodes In addition to the simple way by which a GUI user clicks the mouse to add one mobile node at one time there are several other methods that can be used to add multiple mobile nodes in just one step Insert Multiple Mobile Nodes A user can insert multiple mobile nodes
214. his button will copy a field s current value to the same fields of all channels of the selected link From Aouterd to Hoste From Host to Router Ehi 1 00 Delay 1 00 ius us ETAL Bandwidth 10 00 Mbps Bandwidth 10 00 Mbps eyaL HEH OOO f HER 0 OOOO CTL Down ume Gown lime Start 5 Start s Corel ete The link property dialog box However the same fields of the channels of all other links will not be affected This button can save a user a lot of time when the user wants to change the property of all channels of an optical link to a specific setting The C T A L button stands for Copy To All Links and to all of their channels Clicking this button will copy a field s current value to the same fields of all links and to all of their channels if they are optical links in the simulated network This button can save a user a lot of time For example if a user wants to set the bandwidth of all links to 20 Mbps he she can open up any link s property dialog box change the bandwidth from 10 to 20 Mbps and then click the C T A L button next to the Bandwidth field The bandwidth of all links and their channels if they have any in the simulated network will be changed to 20 Mbps Since links are bidirectional a user can separately specify the down time periods for each direction of a link The down time periods specified for a direction of a link say from node A to node B are autom
215. his node s interface or launch application programs on this node at run time The following figure shows a command console usage in which a tcpdump is capturing packets D s Delt G 7am amp Poo G Seteg A heey eee fee ee BAwe B 8 bt aCe sR E Beebe LT LL SNL LALLA Le L LaicLs eae a eue IFAARA 2 8 ERP BERR t ra wk Tit ti tte st ca 1AM pe ee H oe aa BeO F A command console can be invoked during a simulation In this case a tcpdump is capturing packets in this command console For a router suppose that the user wants to capture the packets flowing through one of its interfaces Further assume that this particular interface is assigned 1 0 2 3 IP address The user can first execute ifconfig a command to find out the information about all of the router s interfaces From the output the user can find the name of the desired interface which is assigned 1 0 2 3 In NCTUns an interface s name is in the ethX XX format where XXX is the interface s port ID After finding the name of the desired interface the user can execute the following command tcpdump i ethXXX to launch the tcpdump program Since the launched tcmdump is the real life tcpdump program all tcpdump options are supported This means that the user can use any packet filtering rule such as tcpdump i eth2 src 1 0 2 1 or tcpdump 1 eth3 w tdump log dst port 8002 The command console is a very useful function A user ca
216. hould run up a coordinator However before running up a coordi nator one should modify the DISPATCHER_IP parameter in which should be in the usr local nctuns etc directory The default value for the DISPATCHER_IP parameter is 127 0 0 1 which means that the coordinator program should register itself with the its coordinator cfg file dispatcher program running on the local machine However for a distributed emulation case most of the coordinator programs launched should register themselves with the same dispatcher program running on a remote machine After starting all participating coordinator programs one can start the GUI program For the GUI program to correctly connect to the dispatcher one should set the IP address of the dispatcher program in its Menu gt G_Setting gt Dispatcher panel So far the setting for the central controller has been completed In the following sections we use several example cases to illustrate the remaining steps to configure distributed emulation cases with different network configu rations Example 1 As shown in the following figure a network 1s composed of two hosts and a virtual router The virtual router splits the whole network topology into two parts The host on the left part of the network intends to transmit TCP packets to the host on the right part of the network The IP addresses assigned to these two hosts are 1 0 1 1 and 1 0 2 1 respec tively TCP Connection As exp
217. hown below On the right hand side of the box one can set up the receiving Rx antenna related parameters such as antenna length and antenna efficiency and the sending Tx antenna related parameters such as Tx power antenna length and antenna efficiency V Module Edit m Parameters Setting Forward Link Return Link TX TX Forward Power w Forward SAT Antenna Length 0 8 im Return Power 10 w Return SAT Antenna Length 0 8 im Forward SAT Antenna Efficiency 0 55 Return SAT Antenna Efficiency loss RX RX Forward SAT Antenna Length 0 8 Return SAT Antenna Length 0 8 rm Forward SAT Antenna Efficiency 0 51 Return SAT Antenna Efficiency 0 51 X Link Failure See Down Time Setting o File Name rard Dvbs2_sat_N1_P1 linkfail Cancel To configure the receiving point at the TG node one can pop up the node editor of the TG node first After double clicking the DVB_RCS_GW module box one will see a dialog box shown below On the left hand side of this box one can set the antenna related parameters such as ground station antenna length and ground station antenna efficiency On the right hand side of this box one can set the rain fade param eters One can either set the desired rain fade directly or set the related parameters such as antenna angle polarization rain height earth station height latitude and rain rate which are u
218. hows an example of the agp file File Edit WL et Scrallback Boc H 15 eee 1 15 8888 z 15 86888 o 1S D 0 HHH 4 15 boo oS 1S5 D HA 6 15 oboe FY LS eee oOo 15 eee E 15 000000 1 LS eee 11 15 8888 lf tL O amp O l5 LS 88808 l4 LS ooo 15 LS 8888 16 Ls amp eooee 17 LS eee 16 15 88800 19 LS ooo The format of the user defined antenna gain pattern file The Coordinate System for Antenna Directivity To correctly specify the directions of antennas one should understand the coordinate system used by NCTUns and the representation of the working field in GUI As shown in the following figure NCTUns uses the fourth quadrant of the Cartesian coordinate system to represent the working field The working field of NCTUns is represented by a rectangle the apexes of which are listed from the top left to the bottom left in the clockwise order as follows 0 0 Max_X 0 Max_X Max_Y and 0 Max_Y where the Max_X denotes the maximum X axis value of this rectangle and Max_Y denotes the maximum Y axis value of this rectangle In this coordinate system the X axis value increases from the left to the right and the Y axis value increases from the bottom to the top which is consistent with what we use in the daily life 0 0 Max_X 0 Working Field 0 Max Y Max X Max Y The reason why we do not use the common first quadrant of the Cartesian coordinate system to represent the wo
219. i a iui 3 oe HWN am j HM ani HE m ay Em a 2 eT mm HH OL ai a i lt 2j aj Taa ALLEE EE 1 m m m i 5 Dhi beet aih tte Show Packet Trace Format This Menu gt G_Tools gt Show Packet Trace Format command shows and explains the format of the output generated by the Menu gt G_Tools gt View Packet Trace command The following figure shows the result of executing this command Display All Node and Link Down Time A user may set down times for nodes and links to test how network protocols would respond to these down times For WDM optical links down times can also be set for each individual WDM channel This Menu gt G_Tools gt Display All Node and Link Down Times command displays the down times specified for all nodes and links in the simulated network A user can execute this command to have a global view of the down times specified for the whole simulated network 42 w Al Node and Link Down Time e Gi Node Down Time Node ID Start sec End sec 2 12 000000 34 000000 f 56 000000 78 000000 Link Interface Down Ti a 1 TE 20 000000 20 000001 20 000001 20 0000014 Set the Frequency of Updating Mobile Node Routing Paths for the GOD Module This Menu gt G_Tools gt Set the Frequency of Updating Mobile Node Routing Paths for the God Module command controls how frequently the routing paths should be recomputed for t
220. ialog box the user can set the start and end time of the RTP example program One out of three RTP example programs can be selected from the Application Name command menu The user then enters the IP address of this host into the Local IP address field and specifies an unused UDP port number for this RTP program For the Canonical name field the user needs to enter a unique name such as shieyuan nctu Then the user needs to specify session and media related parameters for the selected RTP program These parameters should be stored in a SDP configuration file which will be read by the selected RTP program At this time the user can click the Edit and save SDP information to a SDP file button to pop up the following SDP dialog box If a SDP file exists and it can be modified for this RTP example program the user can click the Load button to load its content for modification Otherwise the user will start with a blank SDP dialog box and later on save the entered SDP information into a SDP file 91 Before a user clicks the Edit and save SDP information to a SDP file button if a SDP file name has been specified in the SDP file name field the one next to the Browse to select one if it exists button its content will be loaded automati cally for editing In the SDP dialog box the Email and Phone number infor mation can be omitted The user needs to specify the bandwidth and active period of
221. imulation must be chosen In addition if a user wants to see the display of packet transmission and node movement during a simulation the option Display packet transmission and node movement during simulation has to be chosen Simul at Lom oo O Simulation Speed Real Time Gul GDB De Moving Path Dynamic moving path generation during simulation n Static moving path generation before simulation Packet Transmission and Node Movement A Display packet transmission and node movement during simulation Playback packet transmission and movem ent after simulation Under the GUI tab the ratio of meter pixel can be specified Changing this setting to a larger value e g 100 is useful for a network whose size is physically very large e g the backbone network of USA see the following figure F za brii 2 5 wa TERT F Weiter ig eee ajin ieee eoMB rr aH LALLA SALSA sae o BEEBE Pr EE A888 gt 2 DERP moa ra ee amano mn Sm ak iI Sei T Ifa network is physically very large and nodes need to be placed at their correct positions on a map with the correct physical distances between them it is better to use a larger value for the meter pixel ratio parameter so that node icons can still be seen with the whole 39 Simul ation Simulation Speed Real Time GUI lap De i meter pixel IPC timeout period 600 a sec Proportion U
222. imum range that node 25 can interfere with node 1 and the CRPT value denotes the minimum power threshold value that node 1 should set if it wants to be capable of sensing the trans mission activity of node 25 Node Distance and Physical layer Information Table no Dsarce mean Acan uA im GRP om 10 568 956940 1 000000 1 000000 2673 000000 115 03 g 251 406046 1 000000 1 000000 2673 000000 115 03 8 322 815737 1 000000 1 000000 2673 000000 115 03 T 299 107004 1 000000 1 000000 2673 000000 115 03 6 584 767475 1 000000 1 000000 2673 000000 115 03 5 562 601922 0 001795 1 000000 550 000000 115 03 4 281 007117 1 000000 1 000000 2673 000000 115 03 3 2953 071136 0 107240 1 000000 1530 000000 115 03 2 S64 576770 1 000000 1 000000 2673 000000 115 03 Antenna Gain Pattern and Directivity Y Specaty physical layer and channel sodel parseecters Propagation Channel Model Frequercy Mhz e Thecretca Channel Mode FadingVar 0 0 Path Loss Mode L Tmo Ray Gowri Fading Model amp None Riccar Graorca Channel Mode Tanten m Systenioss 0 Node Conmectivity Display TrarePover dere Use the transmitting node perspective Use the rocio mode perspective AverapeBuidingteignt m Streetwidth m AverapeBukingDistace rn Poth_osseeponert Antenne Gen Pattern and Orectivity StanderdDevietion Recaiusste Coselrivstance m One can click the Antenna Gain Pattern and Directivity button to specify the gai
223. in Height 3 ikm File Name Dvb_s2 feeder N2_P1linkfail Earth Station Height 0 07 km Latitude 24 l degree Rain Rate 50 mmh On the left hand side of this box one can set up the output buffer size the symbol rate and the antenna related param eters such as Tx power ground station antenna length and ground station antenna efficiency On the right hand side of this box one can set up the rain fade parameters One can either set the desired rain fade directly or set the related parameters such as antenna angle polarization rain height earth station height latitude and rain rate which are used to calculate the rain fade 135 When one double clicks the Feeder node one can click the Rain Rate Reference button at the bottom of the popped up dialog box to find out the average rain rate at any location on the Earth The following figure shows the rain rate map E a EF a Se ee pe a ro E ee ge selec a oat m Ja p i O e a F ta 7 z m po Sp i e at a P Tag i E oa p r as AL ee j Paap a ae he r l ag T F r a P F a T z a i P pees Bee eh ra lag E wrnod 3 pe jt r ja nii Tie e F k 4 kea a E ir b ag j r F i ny ih K r i p P i x 1 F a se F 4 1 k F 7 k EA 1 AL w we a Pay y 4 iy I 3 Fe Ae m i ice E aes s d f SE 2s r _ a UE a z ic 4 1 ite Bey k in ray i i jmd a at y f _ i i i nn eee e f j
224. ine are presented in the The Protocol Developer Manual for the NCTUns 6 0 Network Simulator and Emulator Distributed Architecture for Remote and Concurrent Simula tions By using a distributed architecture each component of NCTUns can be run on a separate machine This is called the multi machine mode As such the machine that runs the GUI program can be different from the machine that runs the simulation engine This capability sometimes can have an advantage When simulating a very large case with hundreds of mobile nodes the GUI will consume many CPU cycles to draw the movements of these mobile nodes during the simulation However this will leave few CPU cycles for the simulation engine to simulate the network protocols To overcome this performance problem using the multi machine mode to run the GUI program and the simulation engine on two different machines is a good solution In addition with the job dispatcher program multiple simulation engine machines can be managed by a single job dispatcher This architecture design can easily support remote and concurrent simulations which increases the total simulation throughput when multiple machines are available Because the components of NCTUns use Inter Process Communication IPC that is sockets to commu nicate they can also be run on the same machine This is called the single machine mode In fact because most people have only one computer to ru
225. ing direction the gain pattern the rotating speed etc NCTUns provides three typical antenna gain patterns and allows users to specify their own antenna gain patterns In addition to setting antennas properties using this tool one can easily choose the wireless channel model that should be used in simulation and fill in the parameters required by the chosen model Another way is to use the node editor to choose a channel model and set its parameter values NCTUns provides many different channel models The detailed information about these models can be found in the source codes of the channel model CM module Reference 1 Li Chun Wang Shi Yen Huang and Anderson Chen On the Throughput Performance of CSMA based Wireless Local Area Network with Directional Antennas and Capture Effect A Cross layer Analytical Approach IEEE WCNC pp 1879 1884 Mar 2004 2 NS 2 channel model http www cse msu edu wangbo1 ns2 3 Simon R Saunders Alejandro Aragon Zavala Antennas and Propagation for Wireless Communication Systems the 2nd edition ISBN 978 0 470 84879 1 Wiley May 2007 4 W C Y Lee and D J Y Lee Microcell prediction in dense urban area IEEE Trans Veh Technol vol 47 pp 246 253 Feb 1998 5 Okumura Hata propagation prediction model for VHF and UHF range in the Prediction methods for the terrestrial land mobile service in the VHF and UHF bands Rec ITU R P 529 3
226. ing profile will be opened by the EE hh LG SS 22821 FSADEAE editor One can edit the content of the file to change the car BAr e sR SRR O Deeks Inj ce LIIL PRAKARA A DER P r Tous i profile A profile contains the characteristic values that a car should follow For example the maximum driving speed the maximum acceleration the maximum deceleration etc E o root vin S x File Edit View Serollback Bookmarks Settings Help fasSpeace 15 karcol eration 1 kezel eration WO OLA x ee ac 2 ar ilar The following figure shows the dialog box used for mapping ITS cars to car profiles Currently five profiles are provided for the mapping One can specify what percentage of ITS cars should use a given profile After finishing the percentage assignment one must click the Generate the car profile mapping file button to complete the mapping The GUI program will automatically and randomly assign a profile to each car based on these percentage settings These assignments are saved to a file which will be read by all car agents each of which controls the driving behavior of a car at the beginning of simulation Each time when the Generate the car profile mapping file button is clicked the above operation will be performed again The new assignments may differ from the previous assignments If one wants to change the automatically generated car profile mapping he she can click the
227. ion By changing the behavior of the appli cation running on a node in the emulated network one can observe whether a real world device would respond correctly to the various normal or abnormal requests issued by that application When the number of real world devices that need to connect to a NCTUns emulated network is large the size of the emulated network is large the number of applications that need to be run up on the emulated network is large or the amount of real world traffic exchanged over the emulated network is large some problems may result The first problem is that the NCTUns emulation machine may not have enough network interface cards NIC to independently connect to each of these devices Ideally the NCTUns emulation machine should use a NIC to connect to a real world device so that these devices traffic into or out of the NCTUns emulation machine will not be affected by one another However nowadays a PC normally can only accom modate four NICs at the most Although this problem can be solved to a certian degree by using a multi port switch and connecting one NIC of the emulation machine and all real world devices to this switch cares must be taken to ensure that the traffic generated by different real world devices will not affect each other in the switch The second problem is that the emulation machine may not be fast enough to run the emulated network in real time When a heavy aggregate packet traffic load i
228. ion RuleAdd lines are for the traffic classifier and conditioner located in boundary routers while QueAdd lines are for the packet schedulers located in interior routers RuleAdd uses the common five tuple source IP address destination IP address source port number destination port number protocol to specify a traffic flow The protocol field can be TCP 6 or UDP 17 Any of these fields can be entered the wild card which means don t care The packets of the specified traffic flow are classified to receive the specified PHB service which can be one of BE NC EF AF11 AF12 AF13 AF21 AF22 AF23 AF31 AF32 AF33 AF41 AF42 and AF43 The meter used to measure the usage of a traffic flow is a token bucket Its token rate is rate Mbps and its bucket size is size Mbits When a packet arrives at the token bucket but cannot find a token it cannot be sent out and needs to waitin a queue waiting for the required token The maximum queue length allowed for this queue is set to be maxqlen packets When a packet arrives but finds that this queue is already full it is handled according to the following rules First if it is an EF packet it will be dropped Second 1f it is an AF11 packet it will be downgraded to an AF12 packet and enqueued Third if it is an AF12 packet it will be downgraded to a BE packet and enqueued Lastly if it is a BE packet it will be dropped if the current queue length is greater than 2
229. ion Gain because the relative angle between its main transmission path and the antenna pointing direction is 135 degree On the other hand the antenna gain value of node 2 is 26 5416146 called Reception Gain because the relative angle between its main reception path and the antenna pointing direction is 135 degree lat tec Hi loots Satin H Sete Daiba fre fro ar aaa J moog oyveyvuws Bees if rere Ji LLGRLG OS NSE dD AARAL S DERP I 1 gt none hE BeSESBESs BA 120 degree antenna painting z i direction bs 135 No Gain 10 61975932 W Ta Rx Gain 26 416 46 k 135 pointing ed hy Cirecion 60 degree antenna oe A dP E Hoer tiem Oe ere The Copy of the Antenna Setting to All Nodes After configuring an antenna one can copy the setting of this antenna to those of all other nodes of the same node type by clicking C P A N S T button denoting Copy the Parameters to All Nodes of the Same Type and copy that to those of all other nodes containing the same physical layer module by clicking the C P A N button denoting Copy the Parameters to All Nodes The locations of these two buttons are shown as follows Using Node Editor to Configure Channel Models Another approach to choosing and configuring a channel model and its parameters is by using Node Editor In the following we illustrate how to do this job Choosing and Setting the Used Channel Model via Node Editor As one
230. ion for a simulated network are exactly the same as those for a real life IP network This provides two advantages 1 If a user knows how to configure and operate a real life IP network he she immediately knows how to configure and operate a simulated network in NCTUns 2 Conversely since the configuration and operation of simulated networks in NCTUns are exactly the same as those for real life IP networks NCTUns can be used as a training tool to educate people how to configure and operate a real life IP network In NCTUns many valuable real life UNIX network config uration tools e g route ifconfig netstat and performance monitoring tools e g ping tcpdump traceroute can be directly run on a simulated network to configure and monitor a simulated network Seamless Integration of Emulation and Simulation NCTUns can be turned into an emulator easily In an emulation nodes in a simulated network can exchange real packets with real world machines via the simulated network That is the simulated network is seamlessly integrated with the real life network so that simulated nodes and real life nodes can exchange their packets across the integrated simulated and real life networks This capability is very useful for testing the functions and performances of a real life device e g a VoIP phone under various network condi tions In a NCTUns emulation case an external real life device can be a fixed host a mobile host or a
231. is shown on the screen to indicate the current ring A user needs to sequentially click all switches that should be on the ring Finally the user must click the first switch to close the ring At this time the specified ring is formed and added to the GUI program The following figure shows that a 2F BLSR protection ring has been configured and added to the GUI program Multiple protection rings may be configured on an optical network If they do not overlap there is no problem However if they overlap care must be taken to ensure that the directions of their working rings are the same either fe it D Toan Ae G ig ft Sete Geet Pee jee BAe B e 0 2a See 80 Pre ee LLOLLa ST HARR 2 aD Ee RP BEEBSEa s BB a BUNE p nA E ak il Pee gf uaF A 2F BLSR protection ring has been configured for the circuit switching optical network clockwise or counter clockwise The following figures show that the second and third 2F BLSR protecting rings are added to the same network to protect all optical links These three rings must have the same direction either clockwise or counter clockwise The reason for this restriction is that there can only be one working ring for each direction of an optical link Following this restriction rule can ensure that this property is hold For example the optical link between Ath switch and 8th switch is on both the first ring and the second ring If both rings are clockwise or counter clock
232. it simulates DiffServ boundary and interior routers for QoS provision For GPRS networks it simulates GPRS phones GPRS base stations SGSN and GGSN devices For 802 16 d WiMAX networks it simulates the PMP mode base stations BS and Subscriber Stations SS and the mesh mode base stations and Subscriber Stations SS For 802 16 e WiMAX networks it simulates the PMP mode base stations BS and Subscriber Stations SS For 802 16 j transparent mode and non transparent mode WiMAX networks it simulates the base stations BS relay stations RS and mobile stations MS For DVB RCS network it simulates the GEO satellite Network Control Center NCC Return Channel Satellite Terminal RCST feeder service provider traffic gateway For wireless vehicular networks it simulates ITS cars each equipped with an 802 11 b ad hoc mode wireless interface ITS cars each equipped with an 802 11 b infra structure mode wireless interface ITS cars each equipped with a GPRS wireless interface ITS cars each equipped with a DVB RCST wireless interface ITS cars each equipped with a 802 16 e interface ITS On Board Unit OBU each equipped with a 802 11 p interface and ITS cars each equipped with all of these six different wireless interfaces For mobile nodes each equipped with multiple heteroge neous wireless interfaces it simulates 1 a traditional mobile node that moves on a pre specified path e g random waypoints and 2 an ITS car
233. ithout such information because the GUI program cannot determine the ID of the subnet to which a mobile node should belong the GUI program cannot automatically assign an IP 1 0 subnetID hostNum and MAC address to the mobile nodes To solve this problem the GUI program provides the Form wireless subnet tool for the user to manually group related wireless mobile nodes together to form a subnet To do so the user first selects this tool and then uses the mouse s left button to sequentially click all required nodes When all required nodes have been selected the user clicks the mouse s right button to end the selection process The user must use this tool to select all required nodes to form a subnet For example for an IEEE 802 11 b infrastructure mode wireless network the user must select all relevant mobile nodes and access points to form a subnet The following figure shows an example usage of this tool For this network the user should use this tool to select the three mobile nodes and the two access points to form a subnet With this information now the GUI program knows that the three mobile nodes all reside on the subnet where the access points reside As such the IP and MAC addresses of these mobile nodes can be assigned automatically 29 The Form wireless subnet 4 tool is necessary for various wireless networks including IEEE 802 11 a b infrastructure mode and ad hoc mode wireless networks IEEE
234. ity and efforts for maintaining the WSMP implementation in the kernel To solve this problem NCTUns realizes WSMP by using To enable WSM transmission one only needs to run up two programs WSM user level C C program APIs and WSM_Forwarding in a simulation These two programs have been included in the NCTUns package and will be automatically installed in the usr local nctuns tools directory Their source codes are available in the package tools tactic_api lib directory where package denotes the directory where the NCTUns package is installed One can easily modify these two programs to meet his her own needs Application Resource Manager Application Security Services UDP TCP WSMP LLC WAVE MAC WAVE PHY In the following we demonstrate the steps required to enable WSM transmission in an 802 11 p network The following figure shows the network topology of this example case which is composed of three 802 11 p OBUs an 802 11 p RSU and a host on the Internet 802 11 a PHY SPEC i In this example case the host wants to transmit greedy UDP packets to node 2 the 802 11 p OBU on the top using WSMP The following figure shows the setting of the host node for transmitting greedy UDP traffic to node 2 with the IP 1 0 2 1 So So ee B eekese Inay oo 4 ena2sBue Pp Fo He 0 Oo on on on AA MP le To make the RSU capable of forwarding data packets using WSMP one sho
235. k to execute the Menu gt N_Tools gt 802 11 b Wireless See God ee A A aj La Il pjp Sf Mesh Network gt Specify Dual Radio Frequency The following figure shows the protocol stack of the mesh Channels for Selected Mesh APs command on the selected OSPF access point access points A dialog box shown below will pop up In this V Node AAN aA gt lt box a user can change the frequency channels for all WPHY g0211P YAP VYARP DVB_S2_FEEDER YDVB_S lt gt selected mesh access points in just one step macso21 s02116 macso21 Ji macso21 MeshOsPl yee FIFO FIFO AP MNod MAC8021 MAC8021 V Freguency channel infrastructure mode interface Ad hoc mode interface she he ox oma mm ma Form Wireless Subnet After inserting 802 11 b mesh access points and 802 11 b infrastructure mode mobile nodes a user must use the Form In the parameter setting dialog box of the MeshOSPF wireless subnet tool to select all such nodes to group module an option called Use ETX as the metric of OSPF them together to form a wireless subnet Specifying this routing protocol can be checked The ETX stands for relationship enables the GUI program to automatically expected transmission count metric which is a radio aware assign IP and MAC addresses to all of these nodes saving routing metric for 802 11 It tries to find high throughput much time and effort of the user The formed 802 11 b
236. k consists of three types of nodes the Transparent Mobile Relay Base Station TMR BS H Transparent Relay Station T RS E and Transparent Mobile Station T MS 34 A TMR BS has the same role as the one in the conventional PMP network In addition to connecting to the backhaul network it also acts as a central controller in the network to allocate link bandwidth for the T RSs and T MSs that it manages On the other hand a T RS simply forwards incoming data for its neighboring nodes and leaves the scheduling of these data to the TMR BS Therefore the design complexity of a T RS can be greatly reduced which significantly decreases the deployment cost of the whole network The main objective of deploying T RSs in the network is to increase the overall capacity of the whole network This is accomplished by dividing a non line of sight packet transmission into two line of sight packet transmissions Since these two line of sight packets can be transmitted at a higher data rate due to better signal qualities the overall capacity of the network can be increased In the current implementation for both the transparent mode and non transparent mode a relay station must be fixed and cannot be mobile In addition in the non transparent mode 160 at most four relay stations can exist otherwise the base station will not have enough bandwidth to support all of them This means that in such a condition a TCP flow set up between the base
237. kets from the corresponding socket With explicit binding an application program running on a multi interface mobile node or an ITS car can utilize multiple heterogeneous wireless interfaces at the same time Note that when running on a single interface node an appli cation program need not bind a socket to the IP address assigned to this interface This is because the operating system can automatically use the correct interface by looking up the routing table On a multi interface mobile node and an ITS car however if an application program does not bind a correct IP address to a created socket the operating system will use a default interface to transmit packets written into this socket This result may be undesired for the appli cation program Summary In this chapter we present the concepts of multi interface mobile nodes and ITS cars in NCTUns Insertion of such nodes and specification of their moving paths are illustrated Finally we explain how to write an application program that utilizes multiple interfaces at the same time for advanced applications 21 IEEE 802 16 d WiMAX Networks he IEEE 802 16 WiMAX family of standards is a promising communication technology for future local and metropolitan area networks This standard family defines the specification of the air interface for fixed broadband wireless access FBWA systems Two operational modes are defined in the IEEE 802 16 d standard the mesh and point t
238. knows the Node Editor can show all the protocol modules of a node In NCTUns every wireless node is forced to use the channel model CM module to simulate a 87 wireless channel The CM module provides plenty of wireless channel models that have been published and validated in the literature which are helpful to increase simulation fidelity In addition it provides a unified and clear interface to service physical layer modules of different wireless networks As such one can easily add a new channel model for a specific network type and hook up a channel model to a new network type The following figure shows the protocol stack of 802 11 b infrastructure mode mobile node The circled module is the CM module of this node Node a E ee Select Mode L5 DK una Rear rado TAN OK Cancel One can double click the icon of the CM module to invoke the channel model setting dialog box shown as follows On the left of the dialog box is the parameter setting generic to all of the channel models such as fading variance average building height average building distance street width path loss exponent shadowing standard deviation close in reference distance system loss antenna height and ricean factor On the right of the dialog box is the channel model selection column One can choose the signal propagation channel model that will be used in the simulation in this column NCTUns categorizes the supported chan
239. l the user will need to add back a router and then add back 20 links This tedious task can be easily done by immediately executing the undo function after the delete operation Note that to undo a delete operation there should be no other operation performed between the delete and the undo operations Otherwise the undo function will be disabled by the GUI The label tool allows a user to enter a label e annotation such as Cisco 8100 router into the network topology The user can set the color font font style and font size of the label before a label is added After a label is added the user can use the select tool to move it to any desired place e g next to a router icon or change its attributes by double clicking it Adding labels to a network topology can make it more readable The arrow tool allows a user to add an arrow into the network topology Adding an arrow point to a device icon can highlight the pointed device Normally an arrow is accompanied by a label to describe the pointed device An arrow is added in the same way as a link The user clicks and holds the mouse s left button on one place to fix the tail of the arrow Then he she drags the mouse to the desired position and then releases the mouse button to fix the head of the arrow 22 After an arrow is added a user can move it in three different ways First the user can use the select
240. l quality over the link the bit error rates of the received data packets on both nodes will significantly increase As a result the goodput over the direct link between the TMR BS and the T MS will drasti cally decrease The other is that the TMR BS can use a more robust modulation coding scheme which usually provides a lower data rate for this link The disadvantage of this option is the reduction of the number of bits carried in a physical layer symbol which thus decreases the effective MAC layer data rate over this link Obviously there is a trade off between the bit error rates of received packets and the system throughputs in traditional cellular networks This problem however can be overcome in an 802 160 relay network with the aid of relay stations In the above case instead of using the direct link between itself and the T MS the TMR BS can communicate with the T MS via the T RS 1 e its packets can be sent to the T MS through the T RS Due to shorter distances between the TMR BS and the T RS and between the T RS and the T MS these nodes can adopt modulation schemes that offer higher data rates while maintaining acceptable bit error rates for received packets on the wireless links Therefore it is possible to achieve higher network capacity in an 802 16 j transparent mode network Setting IEEE 802 16 j Transparent Mode Networks In the following we demonstrate how to use the GUI program to conduct an IEEE 802 16 j
241. lace many 802 11 e mobile nodes he she can use the Menu gt N_ Tools gt 802 11 e Wireless Network gt Insert 802 11 e Mobile Nodes command In the insertion dialog box a user can choose how many access points should be inserted and which positioning style random or an array style should be used If a user wants to change the protocol stack of all inserted mobile nodes he she can also do the change here Insert multiple 802 11 e mobile nodes at the same time to save time and effort After inserting 802 11 e mobile nodes a user must use the Form wireless subnet 4 tool to select all such nodes and the 802 11 e access point to group them together to form a wireless subnet Specifying this relationship enables the GUI program to automatically assign IP and MAC addresses to all of these nodes saving much time and effort of the user The formed 802 11 e wireless subnets can be viewed and managed by executing the Menu gt N_ Tools gt 802 11 e Wireless Network gt Manage 802 11 e Infra structure Mode Subnets command The following figure shows the dialog box of this command 4 ee oe ee ee ee ee SoM rr whi KL LALLA TA A BeBe eMeSkts BEA AARS 4 3 4 ee oo 5 g d 4 aa F 0000 00 O00 on A OR ia Configure Application with QoS Parameters When a user specifies an application to be run on an 802 11 e mobile node the 802 11 e QoS para
242. lained previously the virtual router can represent 1 a real router or 2 a layer 2 switch or a crossover Ethernet cable In the following we first show the detailed steps for configuring a distributed emulation case where the virtual router represents a real router Use a real router to connect emulation machines As shown in the following figure a network is composed of two emulation machines and one real router The IP addresses of these two emulation machines are 192 168 1 1 and 192 168 2 1 respectively and these two emulation machines connect to the real router at the two interfaces with 192 168 1 254 and 192 168 2 254 If no other machine is used to run the central controller one of these two emulation machines should be designated as the central controller In this example the dispatcher and the central controller GUI are run on the emulation machine assigned the IP address 192 168 1 1 The first step that one should take is to physically connect these machines to form a connected network as shown in the above figure One then runs the following route commands on the real router route add net 200 2 1 0 24 gw 192 168 1 1 66 Topology Emulation Machine 192 168 2 1 Emulation Machine 192 168 1 1 Real Router 192 168 1 254 192 168 2 254 route add net 200 1 2 0 24 gw 192 168 2 1 The rationale for executing these commands on a real router is explained here A packet with a destination IP address 200 Z X Y
243. lated network to enter the external router This design is required Without such a design if there are two external routers in a simulated network when a packet enters the simulated network after being sent to an external router and then coming back the emulation kernel module will not be able to know from which subnet this packet should continue its journey over the simulated network Suppose that host 2 on the left sends a packet to host 3 on the right Then the destination IP address of the packet will be changed to 200 2 3 1 before being sent to the external router Using the above example to illustrate suppose that link 1 is subnet 1 link 2 is subnet 2 and link 3 is subnet 3 in the simulated network Further suppose that the IP address of host 1 is 1 0 1 1 the IP address of host 2 is 1 0 2 1 and the IP address of host 3 is 1 0 3 1 and the IP address of the external router on link 1 is 1 0 1 2 the IP address of the external router on link 2 is 1 0 2 2 and the IP address of the external router on link3 is 1 0 3 2 Suppose that in the real world the real IP address used by the external router port configured with 1 0 1 2 in the simulated network is 140 113 1 2 the real IP address used by the external router port configured with 1 0 2 2 in the simulated network is 140 113 2 2 and the real IP address used by the external router port configured with 1 0 3 2 in the simulated network is 140 113 3 2 Further suppose that on the simulation
244. le which is used in the protocol stack of an optical edge router in an OBS network summary This chapter presents how to use NCTUns to conduct optical network simulations NCTUns can be used to study tradi tional circuit switching optical networks where protection schemes and routing schemes are the main focuses NCTUns can also be used to study newly proposed optical burst switching networks where burst contention resolutions QoS high link utilization are the main focuses Readers should refer to optical network books and OBS papers to take advantage of NCTUns to conduct optical network simulations Reference 1 C Qiao and M Yoo Optical Burst Switching OBS A New Paradigm for an Optical Internet Journal of High Speed Networks vol 8 no 1 pp 69 84 Jan 1999 2 S Verma H Chaskar and R Ravikanth Optical Burst Switching A Viable Solution for Terabit IP Backbone IEEE Network Magazine Vol 14 No 6 pp 48 53 November 2000 3 M Yoo C Qiao and S Dixit QoS Performance of Optical Burst Switching in IP over WDM Networks IEEE JSAC Vol 18 No 10 pp 2062 2071 October 2000 4 A Detti V Eramo and M Listanti Optical Burst Switching with Burst Drop OBS BD An Easy OBS Improvement Proceedings IEEE ICC 02 International Conference on Conference April May 2002 New York USA 5 S Y Wang Using TCP Congestion Control to Improve the Performances of Optical
245. le name means that the logged performance e g delay jitter loss rate or lost number are the measured performance of the packets exchanged between host i and host and reported by host k A user can see these RTP log files to check whether the packet loss rates reported by RTCP are consistent with the WAN s packet loss rate settings B Tei Gieting N primo freien few bee E ew OS eAvuyvvwag Bees fae JHU LLALLA LS PSR eNO BeSRBSSTEY ES BH AAS hee DERP diti ue a 4 b Il E gt ches Elen z nI T In the following we show the RTP and SDP settings for host1 host2 and host3 respectively In this example the SDP setting for hosti is stored in a file named XXX_Node i sdp and this file name must be entered into the RTP dialog box of host i where 1 1 2 and 3 k WV RIF Application G RIF Application m amp G ame 0000000 tseci Start Time 0 000000 sec End Time 250 000000 isai End Time 250 000000 sec T C bps ae foserer Local IP address 1 0 11 acel IP etka 1 0 1 2 Local port number 5004 Local port number 5004 Canonical name CNAME must be unique a ncetu Canonical name CNAME must be unique b nctu You need to input the SDP file name for the RTP application You need to input the SDP file name for the RTP application amplel_Nodel sdp Browse to select one if it exists amplel_Nodez sdp Browse to select one if it exists Otherwise the required SDP file can be easil
246. left part of the network is 192 168 1 1 and that for the right part of the network is 192 168 4 1 The emulation machine for emulating the middle part of the network has two interfaces with IP addresses 192 168 2 1 and 192 168 3 1 respectively Note that because the network interface with 192 168 2 1 is closer to the left emulation machine where the dispatcher is run than the other network interface the coordinator running on this emulation machine uses 192 168 2 1 to register with the dispatcher It is this reason why later when we configure the entries of the ports of the left and right virtual routers that connect to this emulation machine the IP address specified in their Coordinator IP address fields should be the same and be 192 168 2 1 The IP addresses used on the real router that connects the emulation machines 192 168 1 1 and 192 168 2 1 are 192 168 1 254 and 192 168 2 254 the IP addresses used on the real router that connects the emulation machines 192 168 3 1 and 192 168 4 1 are 192 168 3 254 and 192 168 4 254 In this example the dispatcher program and the GUI program are run on the emulation machine with the IP address 192 168 1 1 aq Aii p Emulation Machine i Emulation Machine PaF Emulation Machine 192 168 1 1 UP 192 168 2 1 192 168 3 1 P 192 168 4 1 Real Router i 192 168 1 254 192 168 2 254 Real Router 192 168 3 254 192 168 4254 After setting up the physical links two types of route commands should
247. less radio to commu nicate with each other to share its locally collected infor mation Using the knowledge of the shared information each network node is able to move in a coordinated manner for some objectives such as chasing a target node exploring the undiscovered area and so on A tactical MANET Scenario Take a tactical MANET as an example suppose that there are several chasing nodes and one target node in such a network Each chasing node first moves towards a random position and tries to detect the position of the target node The chasing nodes periodically use their radios to share their locally collected position information of the target node Upon receiving the position information of the target node a chasing node makes a tactical strategy for capturing the target node For instance they may move along a specific direction for chasing the target node or adopt a more sophis ticated strategy to siege the target node Since mobile nodes in a tactical mobile ad hoc network can move actively such networks are also viewed as one type of active networks Besides the tactical mobile ad hoc network there are various kinds of active networks for example the vehicular network the active sensor network etc Tactical and Active MANET Simulation Nowadays many tactics have been proposed for various objectives based on different battlefield situations Each of them may use a different heuristic or policy Due to the dive
248. links in the working area to connect these nodes together Fle Ede GF Too fToos D Seii A Deia Sinaia View fein XA eo ee eHow eee yea gg f ee ee a ee Es Tr y select wirelens node L 3 falia r 19 rig ron Eo eebewe st FS EUIS right button to end the selection El he 16 20 ERP sto form a subnet click on t a 5 Eo Ge 4 O 000 000 O00 O00 oc mom horn sare Gage 0 090 00 OH Go Si a When nodes and links are added to or deleted from a network topology a node s ID and the ID of its ports interfaces will be automatically assigned and adjusted by the GUI program The GUI program will re number each node s ID when any node is deleted from the topology to make sure that node IDs are continuously numbered For a node when one of its link is deleted the GUI program will also re number the IDs of all of its ports interfaces to make sure that port IDs always start at 1 and are continuously numbered on a node To see where a mobile node has moved to during an animation playback a node s ID is displayed next to its icon at all times on the screen A port interface of a fixed network node is represented by a blue box For wireless interfaces such as those used by WLAN mobile nodes WLAN access points GPRS phones and GPRS base stations they are represented by the wireless signal propa gation waves which indicates the used antenna and it s direction By default the use
249. lock mobile nodes view whether it should block mobile nodes movement and whether it should block wireless signal or just attenuate the power of the signal Sometimes a user may want all obstacles to have the same property that is different from the default property It is tedious to change the property of each obstacle one by one after every obstacle is placed Therefore a user is suggested to change the default property of an obstacle before placing any obstacle by using the Menu gt G_Setting gt Obstacle command After this operation all obstacles added will have the new default property If the user needs to place more 36 Obstacle Properties Block node view Block node movement Block wireless signal Block signal completely O Attenuated by 99999 dbm Width 3 Ea pixels OK Cancel Cancel An obstacle can block node s view node s movement or wireless signal Wireless signal can just be attenuated rather than being totally blocked obstacles with different property he she can use the above command again to change the default property of an obstacle Generate Large Networks To generate a large network topology it is tedious for a network researcher to add nodes and links to the topology editor one at a time NCTUns provides a convenient tool for a user to automatically generate a large network whose structure is similar to that of the Int
250. locks from which various aggregate behaviors can be built A small bit pattern in each packet which is in the IPv4 TOS field is used to mark a packet to receive a particular forwarding treatment or per hop behavior PHB at each network node In a DiffServ DS domain two different types of routers exist They are called the boundary router amp and interior router respectively On a boundary router traffic incoming into the DS domain needs to be classified and conditioned Traffic classification is carried out by a classifier which classifies traffic into different classes based on the traffic profile or the service contract For example one can use the source IP address destination IP address source port number destination port number protocol five tuple to specify a traffic flow and classify its packets into a traffic class Traffic conditioning is carried out by a conditioner which may consist of a meter marker shaper and dropper The function of a traffic conditioner is to meter a traffic flow to see if it exceeds its traffic profile mark the packets whose usage exceeds the traffic profile as low priority packets delay 102 the transmission of these packets or even drop these packets Normally the token bucket scheme is used to specify a traffic profile On an interior router incoming packets are dispatched to different traffic class queues for receiving different QoS treatments Dispatching a packet is bas
251. lowing we briefly explain its capabilities and features High Fidelity Simulation Results NCTUns directly uses the real life Linux s TCP IP protocol stack to generate high fidelity simulation results By using the novel kernel re entering simulation methodology a real life UNIX e g FreeBSD or Linux kernel s protocol stack is directly used to generate high fidelity simulation results Reusing All Real Life Application Programs In NCTUns all real life existing or to be developed UNIX application programs e g the P2P BitTorrent application can be run up on a node in a simulated network This provides several unique advantages 1 These real life application programs generate realistic network traffic to drive simulations which leads to more convincing results than using the artificial traffic generated by some simple toy functions 2 The performances of these real life applications under various network conditions can be evaluated and then improved before they are released to the public For example a network game application can be first tested evaluated and improved on NCTUns before it is released to the public 3 The applications developed at the simulation study stage can be readily used and deployed on real life UNIX machines when the simulation study is finished This will save time and effort significantly Same Configuration and Operation as for Real Life Networks In NCTUns the configuration and operat
252. lowing figure a timeslot is composed of a preamble duration a payload duration and a guard time duration The guard time duration is split into two burst start offset One burst start offset is located at the head and the other one is located at the end of a timeslot One two or four ATM cell s may be carried in the payload portion within a timeslot One has to set the number of ATM cells carried in a timeslot the preamble length the burst start offset which is a half of the guard time period the number of timeslots per frame used for bearing data called data slots here the number of timeslots per frame used for bearing capacity request called request slots here the number of frames per super frame and the used combination of coding and modulation scheme With the above information the GUI program can 128 Guard Time a as Burst Start Offset Burst Start Offset il lt _ Preamble Payload Timeslot Duration automatically calculate the periods of a timeslot a frame and a superframe In addition the maximum channel trans mission capacity can be calculated by the GUI program To set the values of the above mentioned parameters one has to double click the NCC node In the popped up dialog box shown below one has to choose the tab of Return link assignment The desired values should be set on the bottom half of the tab MV ACC ao amp Return link arrangement
253. lti machine mode because simulations are actually performed on a simulation server machine the user must also have the same account on any simulation server machine that is managed by the dispatcher To 15 Preference Job dispatcher IP address 127 0 0 1 Port 9800 User information User name nctuns Passwort eeee Email addres o The user name here cannot be root Otherwise command console function cannot work correct OK Cancel The popped up dialog box for setting dispatcher related infor mation guarantee this property normally a simulation service center will use NFS network file system and YP password facil ities This will make sure that all machines in this service center share the same user account database and share the same file system The user name specified in this dialog box cannot be root That is the GUI user should not use the root account to log onto a simulation server no matter whether it is a local or remote machine This enforcement is for security concerns Also if the GUI user logs on a simulation server as the root user he she will not be able to use the command console function correctly For these reasons the root account is blocked here by the GUI program During simulation i e when the simulation is not finished yet the result files generated by the simulation engine are stored in a working directory inside
254. ly perform a distributed emulation Instead the user can enjoy the many benefits of distributed emulation without such worries and headaches 64 For simplicity the three examples presented in this chapter do not include external hosts and external routers which are presented in the previous chapter about Emulation Actually they can participate in a distributed emulation as well Time Synchronization As presented above an emulation machine is responsible for processing the packet events generated by and destined to the nodes in the part assigned to it When an event should be the local emulation machine should transmit the event to the remote processed by another emulation machine emulation machine as fast as possible ideally taking no time During a distributed emulation the simulation clock of each participating machine is independently synchronized with the real clock on its own machine every 1 ms The real clocks on these machines may be different and they should be synchronized with each other by using the NTP protocol before a distributed emulation is conducted Virtual Router NCTUns uses a virtual router node type E to divide the topology of an emulated network A virtual router can represent a real router or simply a crossover cable or a layer 2 switch which can function as a crossover cable The following figure shows the dialog box of a virtual router which is composed of two panels that are ex
255. lyses This scheme can easily support the server farm model in which multiple simulation jobs are performed concurrently on different simulation servers The following figure shows the distributed architecture of the NCTUns z z Simulation Server E l l Simulation Server E Simulation Server E Simulation Server E GUL Boston NCTU GUI Rome GUL Paris Background Simulation Tokyo Simulation Service Center Kernel Modifications Simulation Engine Protocol Modules Coordinator A Simulation Server The distributed architecture of NCTUns In addition to the above multi machine mode another mode called the single machine mode is supported In such a mode all of these components are installed and run on a single machine Although in this mode different simulation jobs cannot be run concurrently on different machines since most users have only one machine to run their simulations this mode may be more appropriate for them In fact it is the default mode after the NCTUns package is installed Some Screenshots of NCTUns To give readers a quick idea about what the GUI environment looks like some screenshots of NCTUns are shown below Starting Screen Every time when a user launches the GUI program the following starting screen will pop up jie abe Teh G_ Satie fi Suiting v jie ote fi eer i i X Cae ee Ce en en aa ew i a a BOR rre V7 LaALL aL eA e e a e E reso Beeb
256. m uses to determine node connectivity The options in Node Connectivity Determination column are enabled only when the Use the receiving node perspective mode is used As shown in the following figure there are two options in this column 1 Determined by power threshold and 2 Determined by distance The former is the default option used by the GUI program By choosing this option the GUI program will determine node connectivity by comparing the receive power value obtained by a receiving node and a pre defined receive power threshold value The latter option is designed for routing modules that determines node connectivity by comparing nodes distances and a pre defined distance value such as the GOD routing module In the following we explain the meanings of these two options in detail Soocity physical tayer ond channel sodel parm bers L Teen Ray _ Ground Te hone hiie Conmectnety Cisplay Uis tee Grerertiorg fect percocet E Lise the receiving mode perspective W Lonmecirerty Dabana Determined by pisar thiini Detam thy Ertan ARAMA Dan Pattern 4nd Lsrectrerty FenAntemnabieight im 1 5 C 5 F 7 an ested Powe reini Waive CPA 7 Recall that when the Use the receiving node perspective mode is used the GUI program will calculate and show the maximum range that a node X can interfere with the chosen node where node X denotes the set of nodes in the network other than the chose
257. mation on emulation can be found in later chapters Other network device icons include QoS DiffServ network s boundary router QoS DiffServ network s interior router amp GPRS network s GGSN device GPRS network s SGSN device GPRS network s base station Hh GPRS network s phone radio a GPRS network s pseudo switch xE optical network s circuit switch optical network s burst switch Optical network s protection ring creation tool Rl optical network s edge router to edge router s shortest light path creation tool Rf 802 11 b dual radio mesh OSPF using the OSPF routing protocol access point amp 802 11 b dual radio mesh STP v 802 11 b dual radio mesh multi gateway switch 802 11 e WLAN infrastructure mode mobile node 3 and 802 11 WLAN access point H4 using the Spanning Tree Protocol access point The network device icons for IEEE 802 16 d WiMAX networks are classified into two groups The first group is for the PMP mode and includes 802 16 d Base Station BS in PMP mode A 802 16 d Gateway Subscriber Station SS in PMP mode A and 802 16 d Host Subscriber Station in PMP mode J The second group is for the mesh mode and includes 802 16 d Base Station in mesh mode A 802 16 d Gateway Subscriber Station in mesh mode hk 43 and 802 16 d Host Subscriber Station in mesh mode amp The functions of these devices will be explained in a later chapter for IEEE 802 16 d
258. me and the maximum channel trans mission capacity are described below lt Definitions gt SR the symbol rate N_ATM the number of ATM cell per timeslot ramt CST IC Maa CRA bps bhar VODE ops Mon REG bps AES timeo lin suportrames B_ATM 53 bytes the length of a ATM cell 5 bytes for header and 48 bytes for data payload RS 16 bytes additional parity check bytes appended to the original data by using Reed Solomon outer coding CC 2 the multiple on the increase of data length when using Convolutional Coding with 1 2 coding rate QPSK 2 the number of bits per symbol when using QPSK modulation PREAMBLE symbols the preamble length of a timeslot GUARD symbols the guard time period of a timeslot N_DATA_SLOT the number of data timeslots per frame N_REQ_SLOT the number of request timeslots per frame N_FRAME the number of frames per superframe PAYLOAD_SYMBOL The number of symbols required to bear the payload of a timeslot TIMESLOT the period of a timeslot FRAME the period of a frame SUPERFRAME the period of a superframe lt Formulas gt PAYLOAD_SYMBOL B_ATM N_ATM RS CC 8 1 QPSK TIMESLOT ms PAYLOAD_SYMBOL PREAMBLE GUARD SR 1000 FRAME ms TIMESLOT N_DATA_SLOT N_REQ_SLOT SUPERFRAME ms FRAME N_FRAME The maximum channel transmission capacity bps 129 N_DATA_SLOT N_ATM B_ATM 5 FRAME 1000 RCST Grouping E
259. meters demanded by this application should be specified A user can click the Add button under the Application tab and then he she will see the QoS demand parameter configuration part at the bottom of the popped up dialog box which is shown below The meanings of these parameters are defined in the 802 11 e specification A user needs to read the related 802 11 e documents or specifications to understand the purposes of these parameters w Traffic Start time sec Stop time sec 3 H 400 Input file name gos Mechanism O TECLAS User QoS Priority TSPEC Transport protocol CO TSF UDP Downlink Direction DO Uplink Source port number Don t care I Destination port number Don t Eare Traffic stream ID G Mean data rate Nominal packet size Delay bound Maximum service interval Specify 802 11 e QoS parameters when adding an application 119 For example suppose that a user wants to achieve a guaranteed 200 KB sec UDP traffic flow from an 802 11 e mobile node to the 802 11 e access point and he she uses the ttcp t u s p 8000 1 0 1 1 command to launch a greedy UDP traffic generator on that mobile node to send packets to another node with IP address 1 0 1 1 For this particular case the user needs to choose the TSPEC Traffic SPECification option In addition the Transport protocol has to b
260. mote nodes are of the same type The protocol stacks of a node can have two levels In WDM optical network simulations not just each interface needs a protocol stack instead each WDM channel of an interface needs a protocol stack Therefore a two level protocol stack may be displayed in the node editor for WDM nodes The protocol modules at the first level are relevant to an interface while the protocol modules at the second level under an interface are relevant to a WDM channel of that interface The following figure shows an example WV Node Editor 3 1 A AS Add Delete and Replace a Module Here we use an example to illustrate how to replace a FIFO module with a RED module Step 1 We first invoke the node editor of a router so that its initial protocol module chain is shown as follows WV Node Editor MAC80211 VW lt 1 Select Mode Step 2 Then we choose the RED module from the top and place it in the middle working area The resulting screen is shown below WV Node Editor VOPTICAL YOTHERS VPHY VPSBM YRCST_CTL VDVB_ 4 Select Mode x XI Undo Redrawl2 T A H2 T A Step 3 Then we select the X tool button and click the mouse on the FIFO module to delete it The result is shown below Node Editor Q A x YOPTICAL VOTHERS YPHY VPSBM YRCST_CTL VDVB_RCS_GW f gt eas ARP E MAC8023 Step 4 Then we link the RED module with the ARP and M
261. ms The source files of these programs are stored in the tools traffic gen rtp directory of the package for the user s reference A user can reference these source files to understand how to use the provided RTP API If a user wants to experiment a new way of using RTP he she can change the source code of these programs and remake them As long as the names of these programs are not changed these newly built RTP example programs will be used after they are copied to the default usr local nctuns tools directory Using RTP Example Programs In the following we illustrate how to run these RTP example programs in NCTUns simulations Since RTP programs typically are run on hosts and they have a large number of parameters to save the user s time and effort commands for automatically adding and modifying RTP application command strings are provided in the dialog box of a host In the following figure the Add RTP and Modify RTP buttons are provided for this purpose Host ID f Name HOSTI Application Down time Mobile IP Start time s Stop time s Command Input file name Add Modify Add RTF Modify RTP Delete App Usage Command console OK Cancel Node editor When a user clicks the Add RTP button the following RTP dialog box will show up In this d
262. n use this console to launch application programs at run time to generate traffic For example while the simulation is running the user can open a receiving node s command console to launch the rtcp p 8000 TCP receiving program and then open a sending node s command console to launch the stcp p 8000 1 0 1 2 TCP sending program assuming here that the receiving node has an interface assigned 1 0 1 2 IP address In addition executing the ping command in a command console is very useful Doing so can help a user find out whether the routing path between two nodes has been correctly set up during simulation The simulation engine of NCTUns is a discrete event simulation engine Thus its simulation clock may advance faster than the real world clock To allow the user to take his her time to type commands in a command console it is suggested that the speed of the simulation is set to As fast as the real world clock which can be done in Menu gt G_Setting gt Simulation gt Speed tab rather than the default As fast as possible To quit a command console a user can use the mouse to kill the xterm window All command consoles will be automati cally killed by the GUI program when the simulation is finished stopped aborted or disconnected Note that an output file generated by an application program invoked in a command console will be transferred back to the simulation case s XXX results director
263. n link The SP is the gateway that interconnects a DVB RCS network and any kind of supported networks in NCTUns In other words any network traffic generated from a RCST has to be routed to external networks through the SP and vice versa The TG is the gateway that receives return link signals issued by the RCSTs It is responsible for delivering the signals to the NCC and the SP The Feeder is responsible for issuing forward link signals that contain management and data messages sent from the NCC or the SP The Pseudo Switch is a virtual node that does not really exist in a DVB RCS network It is used in the NCTUns s GUI program to graphically interconnect a NCC a SP a Feeder and a TG During simulation transmitted messages are exchanged directly from the NCC SP to the Feeder or from the TG to the NCCY SP and they do not pass through the Pseudo Switch at all The Satellite is a GEO satellite with transparent transponders In other words it is just a signal repeater The Satellite receives the signals from uplink channels amplifies them and transmits them on the downlink channels The RCST can be used as an independent terminal device or as the gateway to a closed network such as an enterprise Intranet or a remote LAN The only communication paths i wE E E a r Da that a RCST has are the forward link and the return link provided by the satellite infrastructure The following figure shows an example DVB RCS network txXAwv
264. n node itself As such if the Deter mined by power threshold option is chosen it means that NCTUns will calculate the interference range of each node X for the chosen node by comparing the calculated receive power value transmitted by node X on the chosen node and a user defined Carrier Sense Power Threshold C S P T value If the former is larger than the latter it means that node X can interfere with the chosen node under the current setting Otherwise node X cannot interfere with the chosen node Note that when using this node connectivity determination mode one is required to properly set the values of the RxAntennaHeight and C S P T parameters so that the GUI program can automatically and correctly determine node connectivity If one is not sure what values are suitable for the used network type NCTUns lists suggested power threshold values for several networks that have strictly defined these values One can click the Suggested Power Threshold Value button to show the suggested power threshold value table The following two figures show where the values have to be set and the suggested power threshold value table respectively 79 Specify physical layer ond channel aadel p rimcters Prope tag heared Mogi Thewelca Chane Mode Path Lant Mined E Two Ray Gore Fading Miga ik Mone Empirica Chamel Feia Hok Oonmectnaly Cipi lka bhe brarcercal trey coke pa k Use the rrei mode perspecti
265. n pattern of a node s antenna and its directivity setting The following figure shows the dialog box for configuring these two properties of an antenna V Properties of omnidirectional directional rotating Antenna 360 00 v degrees 60 degree antenna pattern oo 00 degree 120 degree antenna pattern Rotating Angular Speed 0 00 degree sec The antenna gain pattern of a 3 dB beamwidth 120 degree or a 60 degree directional antenna can be shown by clicking on the above two buttons respectively The antenna gain is expressed in dBi and each number represents the gain in a particular degree The first number is the gain along the pointing direction Then each successive number 3 dB Beamwidth Pointing Direction I Use user defined antenna gain pattern Antenna pattern file represents the gain in the next degree clockwise In total 360 gain numbers are calculated and listed When the 360 degree option omnidirectional is chosen the antenna gains in all 360 degrees use the same value of 2 dBi Note If the Use user defined antenna gain pattern option is enabled the Channel Model CM module will use the user specified antenna gain pattern to model a simulated antenna regardless of the specified 3dB Beamwidth setting Note The IEEE 802 16 e specification has defined the mandatory antenna gain values for the BS and MS nodes These values have been specified in the 80216e_pmp_bs agp and 80216e_pmp_ms agp files resp
266. n their simulations the single machine mode is the default mode after the NCTUns package is installed Switching between these two modes is very easy and requires changing only one configu ration option in a file Components and Architecture of NCTUns NCTUns adopts a distributed architecture It is a system comprising eight components 1 The first component is the GUI program by which a user edits a network topology configures the protocol modules used inside a network node specifies mobile nodes initial location and moving paths plots performance graphs plays back the animation of a packet transfer trace etc 2 The second component is the simulation engine program which provides basic and useful simulation services e g event scheduling timer management and packet manipu lation etc to protocol modules We call a machine on which a simulation engine program resides a simulation server 3 The third component is the set of various protocol modules each of which implements a specific protocol or function e g packet scheduling or buffer management All protocol modules are C classes and are compiled and linked with the simulation engine program 4 The fourth component is the simulation job dispatcher program that can simultaneously manage and use multiple simulation servers to increase the aggregate simulation throughput It can be run on a separate machine or on a simulation server 5 The fifth c
267. nce to successfully reserve their required resource In contrast the control packets associated with low priority bursts will less likely make successful reservations As such they and their corresponding bursts will experience a higher drop rate This control packet signaling protocol is purposely designed to be one way rather than two way That is the source node need not wait for the reply of the source to destination reser vation request to come back before sending its burst If instead a two way signaling protocol is used in optical networks with high link bandwidth and large RTTs tremendous optical bandwidth would be wasted during the RTT because no packets can be sent during this period of time In contrast using the proposed one way signaling protocol this period of waiting time can be reduced to a fixed and tiny value which is the used time offset In today s WDM networks circuit wavelength switching optical packet switching and optical burst switching are the three main competing technologies Potentially the optical packet switching technology can provide the highest link utilization among the three technologies However it is not mature yet The circuit wavelength switching technology is practical and being used However its link utilization is low The optical burst switching technology can be thought of as a compromise design between the optical packet switching and the circuit wavelength switching technologie
268. nd rtcp and start executing the simulation Optical Burst Switching OBS Network Optical burst switching OBS 1 2 is a method for trans porting traffic over a bufferless optical WDM network At a source node packets are grouped into a burst and sent together as a unit before they are switched through the network all optically Before sending a burst the source node first sends a control packet along the burst s routing path to configure every switch on the path The control packet is sent over an out of band channel It will be electronically processed at each switch so that the switch can allocate resources e g schedule transmission time slots for its burst in real time The time offset between sending the control packet and its burst should be large enough This is to ensure that the control packet can always arrive before the corresponding burst at each intermediate switch The following figure shows the mechanism of the OBS network SRC SWI DST SW2 Control Offset Time Burst Time The source node separates the transmissions of the control packet and the burst by an offset time Because the control packet needs to be electronically processed at each intermediate switch it will be slightly delayed compared to the burst transmission in the optical domain The control packet contains information about routing the burst length and the offset time The routing information is for the switch to decide the
269. nel models into two classes One is the Theoretical Channel Model class which collects the channel models that are developed using theoretical formulas In this class one should first select the path loss model that is intended to be used in the simulation and then can optionally select a collaborative fading model to more realistically simulate the fading effect Currently NCTUns supports three theoretical path loss models which V Module Edit 00 Q Parameters Setting Fading Variance hod Average Building Height m hoo ia Path Loss Model fTwo Ray Ground Average Building Distance m bo Fadin Model None Street Width m hoo l C Empirical Channel Model Path Loss Exponent ba Suburban 1 9G Shadowing Standard Deviation ko Close in Reference Distance m 0 System Loss 0 Antenna Height m hs Ricean Factor K db 110 0 Cancel Propagation Channel Mode Theoretical Channel Model n_1_9GHz_TB are listed as follows in sequence Free_Space Two_Ray_Ground and Free_Space_and_Shadowing and three different fading models no fading None Rayleigh Fading and Ricean Fading The other model class is the Empircal Channel Model class which collects channel models that are developed based on real life measurement results So far NCTUns supports 23 empirical channel models e g LEE Microcell Okumura COST_231_Hata and so
270. net from this dialog box and delete it by clicking the Delete button D M DVB RCS Subnet D D B_RCS Subnet Subnet ID LSAT INCC SP Feeder Sateway RCST RI 1 21 5 2 36 31 EE 4i Delete b ok Cancel S cceccccccccccsccccccccccccoes J Channel Assignment In a DVB RCS system the forward link and the return link are employed to provide two way data exchanges between service providers and end users One has to complete the channel related configurations for these two links In the current implementation of DVB RCS only one channel is used on the uplink of the forward link and also only one channel is used on the downlink of the forward link Like that shown in the following figure one has to assign the central frequencies for both of the uplink and downlink frequency bands The value of the central frequency will be used to calculate the BER Bit Error Rate on the uplink downlink when a simulation is running The whole uplink frequency band is automatically designated as channel 0 and the whole downlink frequency band is automatically designated as channel 1 The following figure shows the forward link channel assignment used in NCTUns Frequency cho central frequency i uplink frequency band chl central frequency downlink frequency band Time Forward link channel assignment To set the value of the central frequency one has to first change the operating mode from Draw
271. network The key difference between them is how the framing information is transmitted Unlike the T RS in an IEEE 802 160 non transparent mode network non transparent relay stations NT RS Cho do not simply forward the incoming data packets Instead a NT RS transmits its own frame header information which contains essential control message and data scheduling information and thus it can schedule its own control messages and data transmissions An NT RS could either operate in the centralized mode or in the distributed mode In the former mode the resouce allocations for all nodes in the network are scheduled on the NT MR BS A s while in the latter mode NT RSs can make their own sched uling decisions for the NT MS Joh associated with them Due to these characteristics of NT RSs a non transparent mode network can operate over a network topology that contain two more hops Therefore the main advantage of this mode is extending the signal coverage of a BS In the current implementation of NCTUns an 802 16 j non trans parent mode network is restricted to only two hops and use the centralized scheduling The following figure illustrates a typical example of IEEE 802 160 relay WiMAX network operating in the non trans parent mode As shown in the figure the NT MR BS connects to a host via a fixed link and forms a subnet together with other NT RSs and NT MSs In this example the NT MS is located out of the signal coverage of
272. nfig urations into the tpl and tcl file respectively This case can later be reloaded Save as Save the current simulation case s topology and node config urations into a new file suite The name of the case shown on the screen is changed from the current case name to the new case name Print to File Capture the network topology area shown on the screen and save it to a bmp file The captured graph can later be sent to a printer for printing or be included in a technical report for illustration Background Job Management Any background job submitted to the dispatcher can be manipulated here They can be deleted stopped aborted or retrieved The following figure shows the dialog box of this function M Background Job Managemen Current Waiting Jobs O Refresh Cancel Job Name Status Submit Time Start Time End Time Job ID Request SimTime Proc The Refresh button is used to update the information shown in this table Each time the user clicks this button the GUI program will retrieve the most up to date information about each background job from the dispatcher Setting the Simulation Dispatcher The command for setting the dispatcher used for the current simulation case is located in Menu gt G Setting gt Dispatcher Job dispatcher P addres 77 00 1 Port 900 User information User nam jnctuns Passwort eee Email addres The user name here cannot be
273. ng channel numbers In a GPRS network neighboring base stations use different frequency channels to avoid signal interference and packet collisions Therefore the user needs to be careful when assigning frequency channels to base stations Base Station Down time Frequency channel Channel slot Neighk starting Frequency Channel Ending Frequency Channel Node editor ok Cancel When there are many base stations in a GPRS network opening the dialog box of each base station to configure its channels may be tedious To do this task a user can execute the Menu gt N_Tools gt GPRS Network gt GPRS BS gt Assign Frequency Channel command to specify how many channels a base station should use This command will automatically give every base station the specified number of channels Note that the channels that are automatically assigned by the GUI are totally different Thus no base station will be given a channel that is already given to another base station In the real world channel re using is commonly performed to save the number of required channels for a GPRS network However during this automatic channel assignment process no channel re using is attempted because the GUI lacks the required intelligence to perform this task Assign Frequency channel ih k al 99 In the Channel Slot tab of the base station dialog box a user can specify how many time slots are allocated to the
274. ng the map to get the 1 1 ratio the background graph will become very huge and thus only a very small part of it can be shown on the screen The user can use the view the whole field tool button to view the whole background graph Ss Cf Gee GP oe Dey Seng m jja x A eo yan od EAD LET EEEL a i C CES TAE MELTE hS ie a k a e a E a L TOLLAND aen enea hal SIDERP r f a FN s l i m aa i i ks E hs F Ki a a Rey pa a Ki w of J im ns saa sai om aaa AAJA I a Hae 3 Set Background Graph Brightness Normally the user will place the icons of network nodes on top of the background graph To achieve a better visual quality it is better to brighten the background graph a bit This command allows the user to adjust the brightness of the background graph in a fine grain way After a series of operations now the background graph is properly set When a user saves a simulation case the current background graph settings will be saved to the file as well Therefore next time when the user re opens the simulation case file tpl the background graph will automatically be set up without the user s help Import Mobile Nodes and Their Paths from File 35 s Doi G Teis hi foe G Bevy ij being Beu ee jai SA Ee Peevey ye ea aa ee sia tx Ae oe ao EI rr 9 WO LLALL SIS AAS A LSS sabe i TELL LEERI BBY LAARA 22 DER P i PT al 0 1 00 0 om A A H ll eee g
275. ntenna efficiency On the right hand side of this box one can set up the rain fade parameters One can either set the desired rain fade directly or set the related parameters such as antenna angle polarization rain height earth station height latitude and rain rate which are used to calculate the rain fade V Module Edit AA RCST Parameters Setting Rainfade Default LDPC Iteration Threshold Ground Station Antenna Length B rn Interface Number 1 ok Rain Fade 20 Cancel User Defined Ground Station Antenna Efficiency loss degree Antenna Angle 89 X Link Failure aoe Polarization 0 degree See Down Time Setting 0 for horizontal polarization 45 for circular polarization File Name rd Dvb_s2_rcst_N7_P1linkfail 90 for vertical polarization Rain Height 3 1 ikm Earth Station Height 0 07 km Latitude 24 degree Rain Rate 50 mmfh The following figure shows where one can set parameters for the return link These places include the sending point at a RCST node the receiving point at the Satellite node the sending point at the Satellite node and the receiving point at the TG node Jpn ose g eee se ae we Xx A eo aonn rr ad LLALLA ff RLALLS FSR e AO BOCEBBESEtE REA AARAA CERP lt Forrard Link M OS I y i M Fi w Fi i Rx gt Op o Tx sf Ly a To configure the sending point at
276. o c ts RE ew RB eAVe Ae eee eSB es i Hj as BBR RB rr VW LLALL GS 8 ALAA FSR eA eee ewSEker ABH AL amp a amp _eapErRP Po Fa 1 a Fi 1 Pa F tA E TA r a 5 A a w 1 xz a Feeder Traffic Gateway P A EER taturn Channel Satell i ps Keteork Control Center Serv tog Provider 0 00 00 om om GG hiie im A DVB RCS network with seven kinds of network nodes When placing a satellite node in the working area one will see a popped up dialog box The altitude of the satellite can be specified in this dialog box GD aaa Extended Network Topology The following figure shows an extended network topology based on a DVB RCS infrastructure In this figure one sees that a fixed network is attached to the SP and a LAN is attached to each RCST IEA Auta ERB SERRE BP d Utt TES as EEU FEE Jib LESLLE LE LTAL LE PRR a BREE SHE BE AAS ca DER P t 1 20 00 on A br ieee An extended DVB RCS network 125 Subnet Formation After setting up the desired network topology one has to specify the subnet scope of a DVB RCS network so that the GUI program can automatically assign an IP address to every layer 3 network interface To do so one first left clicks the form subnet icon on the tool bar then in turn left clicks all required nodes to form a DVB RCS network The required nodes include one Satellite node one TG node one Feeder node one NCC node one SP node
277. o multipoint PMP modes In this chapter we present how to conduct a simulation of IEEE 802 16 d networks over NCTUns IEEE 802 16 d Mesh Mode Concept The IEEE 802 16 d mesh mode is designed for constructing the next generation wireless metropolitan area networks Wireless MANSs It can support multi hop communications and allow for more flexible network topologies as compared with the PMP point to multipoint mode There are two types of nodes in an IEEE 802 16 d mesh network mesh base station mesh BS and mesh subscriber station mesh SS nodes A mesh BS node p manages the network and connects to the backhaul network 1 e the Internet On the other hand mesh SS nodes represent IEEE 802 16 capable terminal devices and can forward packets among themselves In NCTUns the mesh SS node is further divided into two types One is the mesh gateway SS node and the other is the mesh host SS node A mesh gateway SS node h r can perform the routing and self configuration functions In addition it can connect the mesh network to another network and route packets between the two networks In contrast a mesh host SS node Ab represents a terminal device equipped with an IEEE 802 16 d interface Mesh host SS nodes can forward packets among themselves However a mesh host SS cannot connect to another network The following figure shows an example of the IEEE 802 16 d mesh network The mesh BS node connects to the Internet at
278. ocation The following figure shows where these two buttons are located aa Q RCST Bandwidth Allocation Traffic Flow Queue ID Src IP l 1 0 1 2 1 0 3 3 1 0 4 4 1 0 4 Src Port Dst Port Protocol 300 400 TCP 400 500 UDP 400 500 TCP 400 500 UDP J Queue Associate Flow with Queue Disassociate Flow with Queue ity yis 1996800 bps ry is 998400 bps ty is 460800 bps aaa TEEN ae eS Zea a l When clicking the Associate Flow with Queue button one can define a flow and specify to which queue this flow is to be delivered in the popped up dialog box The five tuple flow identifier includes the source IP address the destination IP address the source port number the destination port 132 number and the protocol Only TCP and UDP protocols are supported in the current implementation The following figure shows the dialog box of the traffic flow definition T D D a Traffic Flew Queue ID Source IP Destination IP source Port Destination Port Protocol Type After completing the flow definition and the flow to queue mapping one has to specify the capacity request strategy packet scheduling strategy applied to each queue This can be done on the bottom half of the tab of RCST Bandwidth Allocation whose dialog box is shown below Anica Dow iene WZT Diietendth ASS Tee Guave Trame F hoa Q
279. ol stack of each DVB RCS node can be popped up by first double clicking each node and then clicking the Node editor button at the bottom of the popped up dialog box The following figure shows the protocol stack of the NCC node V Node Editor a K MAC8O211 WPHY 80211P AP ARP DYB _52 FEEDER DYB 2 RCST FWD 4 gt lt lt Mac o211 z ile Mac o211 MAC OZ211 gt gt i NCC NCC_CTL icin 4 Return link Forward link The following figure shows the protocol stack of the SP node Node Editor D O G MACBO211 WPHY 80211P DYB_S2 FEEDER DYB_S2 RCST FWD 4 gt Return link Forward link lt Select Mode k x Undo Redraw CTAR CTAN cancel The following figure shows the protocol stack of the Feeder node Node Editor ORN MACBO211 WPHY 80211P AP ARP DYB S2 FEEDER DYB 52 RCST FWD 4 gt Forward link B eh Select Mode k X Undo CTAP CTAN i Cancel The following figure shows the protocol stack of the TG node Node Editor MAC80211 WPHY 80211P AP ARP DVB_S2_FEEDER DVB_S2 RCST FWD lt gt a Return link EI Select Mode The following figure shows the protocol stack of the Satellite node Node Editor Return link Forward link The following figure shows the protocol stack of the RCST node Node Editor MACSBO211 WPHY 80211P
280. ollowing figure shows the dialog box of this command Graph Title This field sets the title of the graph Show Grids in Background This field sets whether the grids should be visible X label This field sets the label of the X axis 53 General Setting De G Graph Title Graph Title X Show Grids in Backgro X axis Setting x label time Width 5 2 sec 10 B l sec Interval of Grid Y axis Setting Y label value Range Min 0 Max 1330 B h3 Interval of Grid 0 State Transition Performance Curve Style c Lines Points Legend Setting The legend and color of a performance curve can changed by double clicking the legend Apply Cancel Width X axis This field specifies how many seconds worth of data should be displayed in the graph window Interval of Grid X axis This field sets the grid interval of the X axis This value will be multiplied by 0 1 to derive the interval between two consecutive grids on X axis Y label This field sets the label of the Y axis Range Y Min This field sets the minimum value of the Y axis Range Y Max This field sets the maximum value of the Y axis Interval of Grid Y axis This field sets the grid interval of the Y axis Performance Curve Style Line Points Selecting this option specifies that the performance curve should be drawn using straight lines to connect adjacent points Performance Curve Style
281. omponent is the coordinator program On every simulation server the coordinator program must be run up The coordinator should be alive as long as the simulation server is alive When a simulation server is powered on and brought up the coordinator must be run up It will register itself with the dispatcher to join in the dispatcher s simulation server farm Later on when the status idle or busy of the simulation server changes it will notify the dispatcher of the new status This enables the dispatcher to choose an available simulation server from its simulation server farm to service a job When the coordinator receives a job from the dispatcher it forks a simulation engine process to simulate the specified network and protocols It may also fork several real life application program processes specified in the job These processes are used to generate traffic in the simulated network When the simulation engine process is alive the coordi nator communicates with the dispatcher and the GUI program on behalf of the simulation engine process For example the simulation engine process needs to periodi cally send its current simulation clock to the GUI program This is done by first sending the clock information to the coordinator and then asking the coordinator to forward this information to the GUI program This enables the GUI user to know the progress of the simulation During a simulation the GUI user can also on line set
282. onitor the signal strength of these neighboring BSs Node editor Cancel Protocol Stack In the following the protocol stacks used by GPRS devices are shown Phone Node Editor Se Select Mode k X Undo Redraw gt 7 A F gt T A Base Station WV Node Editor p Select Mode Redraw T A S T AN SGSN Node Editor Select Mode k x Undo Redraw 2 T A sag 2 8 do Select Mode Xel Protocol Modules In the following the parameters of some protocol modules are shown and explained BTSMAC The parameters provided in the BTSMAC module deal with channel and time slot usages The values of these parameters shown in the module dialog box reflect the values set in the Frequency Channel and Channel Slot tabs of the dialog box of the base station The Base Station Identity Code BSIC is assigned by the GUI automatically Each of the base stations that connect to a single SGSN is assigned a different number ranging from 0 to 7 The maximum number of base stations that can connect to a SGSN is 8 The following figure shows the dialog box of the BTISMAC module Module Edit Parameters Setting Base Station Identity Code BSIC starting frequency channel Ending frequency channel Uplink time slot number Downlink time slot number Summary This chapter presents how to use NCTUns to conduct GPRS simulations A GPRS network is a complicated network with
283. ontrol over its execution Job control commands are grouped in the Simulation menu The following explains the function of each job control command e Run Start to run the simulation e Pause Pause the currently running simulation e Continue Continue the simulation that was paused e Stop Stop the currently running simulation e Abort Abort the currently running simulation The difference between Stop and Abort is that a stopped simulation job s partial results will be transferred back to the GUI program However an aborted simulation job s partial results will not be transferred back Instead they will be immediately deleted on the simulation server to save disk space e Reconnect The Reconnect command can be executed to reconnect to a simulation job that was previously discon nected All disconnected jobs that have not finished their simulations or have finished their simulations but their results have not been retrieved back to the GUI program by the user will appear in a session table next to the Reconnect command When executing the Reconnect command a user can choose a disconnected job to reconnect from this session table Disconnect Disconnect the GUI from the currently running simulation job The GUI can now be used to service another simulation job A disconnected simulation job will be given a session name and stored in a session table 18 e Submit as Background Job Submit a job
284. oot tent N Teforeat on Firm rimiatjoa agja ing Simulation View Halo IBes RSE Eal 2 S IALOLLS Can Information Time 13 17 Mode ID 5 Module OFDMA_PMPMS_NT Message M5 5 Drop RS 4 s Access Bursi Il already Tima 13 17 1 Node ID 5 Module OFDMA PMPME WNT a Message MS 5 Drep AS 2 s Access Burst I already A Time 13 17 Node ID 5 Module OFDMA_PMPMS_NT 50 7 ee Ee PETTE a yoo o y hs To dynamically transmit messages to the GUI program a protocol module has to use specific message passing APIs provided by the simulation engine instead of using tradi tional message printing library calls such as printf More information about these APIs is explained in the The Protocol Developer Manual for the NCTUns 6 0 Network Simulator and Emulator View Packet Trace It is useful to view the packet trace file in a human under standable way Viewing this file can help a researcher debug a network or a protocol To do so a user can execute Menu gt G_Tools gt View Packet Trace to open the desired ptr file The binary ptr file will be converted to text by the printPtr tool automatically and shown in the popped up window The text is shown by the more program which supports vi like search commands HA o E es os GekR SAGES Bebb s Teey lee BOOM ttre SHLLSILLSE LS LLSELLS OSESEAE BEMBONESP BEN SARRRRe eM DERP ALEF EFEEEEE zart Tas an i matrrelt I Em NM he
285. or get an object s value e g to query or set a switch s current switch table Message exchanges that occur between the simulation engine process and the GUI program are all relayed via the coordinator 6 The sixth component is the kernel patches that need to be made to the kernel source code so that a simulation engine process can run on a UNIX machine correctly Currently NCTUns 6 0 runs on Red Hat s Fedora 11 which uses the Linux 2 6 28 9 kernel 7 The seventh component is the various real life user level application programs Due to the novel kernel reentering simulation methodology any real life existing or to be developed application program can be directly run up on a simulated network to generate realistic network traffic 8 The eighth component is the various user level daemons that are run up for the whole simulation case For example NCTUns provides RIP and OSPF routing daemons By running these daemons the routing entries needed for a simulated network can be constructed automatically As another example NCTUns provides and automatically runs up several emulation daemons when it is turned into an emulator Due to this distributed design a remote user can submit his her simulation job to a job dispatcher and the dispatcher will then forward the job to an available simulation server for execution The server will process simulate the job and later return the results back to the remote GUI program for further ana
286. ordinator programs Their names are dispatcher cfg and coordinator cfg respectively Some other configuration files used by NCTUns are also stored here For example the app xml which is read by the GUI program to explain the usages of pre installed application programs is also stored here An mdf subdirectory which stands for module definition file is created here Inside this directory the parameter definitions and dialog box layout design of supported protocol modules are stored in separate subdirectories The GUI program will read the files inside the mdf directory to know the definition of supported protocol modules The ps cfg file describes the default internal protocol stack used by each supported network node 4 usr local nctuns BMP This directory stores the icon bmp files used by the GUI program These icon files are used for displaying various devices icons and control buttons 5 usr local nctuns lib This directory stores the libraries used by the simulation engine For example the more advanced signal propagation model library used by IEEE 802 11 b advanced wireless physical module is installed here NCTUns supports RTP RTCP SDP protocols and implements some of their functions as a library that can be called by RTP RTCP SDP application programs Installation Procedure Before starting the installation a user should first carefully read the README and INSTALL fil
287. ort the moving paths of a case to a mdt file and then see its content The import function is very useful for large scale simulation cases where the number of mobile nodes is very large and the lengths of their moving paths are very long In such a situation the mobile nodes locations and their moving paths may better be generated by a script program which will save the user a lot of time and effort This facility is also very useful for using a special mobility pattern that is not supported by NCTUns Right now NCTUns can only automatically generate random way points paths for mobile nodes or allow a user to manually specify the moving paths of mobile nodes However in some cases a user may want to study a mobile network with a different mobility pattern For example when using NCTUns to study ITS intelligent transportation systems problems we can first use a micro scopic vehicle traffic simulator e g VISSIM to generate more realistic moving paths of vehicles moving on a highway or in a city Note VISSIM considers the car following and lane changing driver s behavior A user can write a simple program to convert the moving path log file generated by a third party program e g in this case VISSIM to a mdt file and then import it into the GUI 32 After importing a mdt file the user can further use the Background Graph function of NCTUns to paste the used highway or city map onto the background of the topolog
288. ound in 3 and more information about SIP can be found in 4 RTP RTCP Library and Example Programs Unlike TCP which is mostly implemented in the kernel of an operating system RTP and RTCP protocols mostly are imple mented in real time application programs In NCTUns a RTP RTCP library is provided so that an application program can easily use RTP and RTCP to transport real time data The binary and source files of this library are stored in the lib librtp directory of the package for the user s reference In addition to the RTP library in NCTUns three example application programs that use the RTP library are provided to demonstrate how to use the API functions provided by the RTP library The names of these programs are rtprecvonly rtpsendrecv and adapt_bw respectively The differences between these programs are explained below Rtprecvonly receives RTP and RTCP packets sends RTCP packets but does not send RTP packets Rtpsendrecv sends and receives RTP and RTCP packets The above two programs use a fixed rate to send their RTP packets based on the specified session bandwidth selected media type and the used codec scheme On the other hand adapt_bw uses RTCP packets to report the received quality of service at the receiver so that the sender can dynamically adjust the sending rate of its RTP packets In the dialog box of every host a RTP command menu is provided for the user to quickly select one program from these progra
289. outgoing interface for the burst The length information tells the switch how much time the burst transmission will last The offset time information lets the switch know that a burst will arrive after a time interval given by the offset time With these information the optical switch will try to reserve the specified period of time at the chosen outgoing interface for the burst If that period of time has not been allocated to any other burst the optical switch can successfully make the reservation Otherwise the switch 111 simply discards the control packet without returning any feedback to the source node At each intermediate switch when the control packet arrives the optical switch performs the same procedure to reserve resource for the control packet s burst This operation repeats until the control packet successfully reaches its destination node or is discarded at some switch In OBS burst priority and QoS can be supported in various ways For example a newly arriving high priority burst may be allowed to preempt a low priority burst that already made a successful reservation In 3 the authors proposed using different offset times for different burst priorities The offset time for a high priority burst is set to be longer than that for a low priority burst With such a setting because the control packets associated with high priority bursts can reserve their required resource at an earlier time they will have a higher cha
290. ow the request will be granted Otherwise the request will be rejected IEEE 802 11 e Protocol Stack The following figures show the protocol stacks of the 802 11 e mobile node and the 802 11 e access point The QoSMN and 8021le modules used inside the 802 11 e mobile node do not need special parameter settings Similarly the QoSAP and 802 1le modules used inside the 802 11 e access point do not need special parameter settings MAC80211 WPHY 80211P_ AP_ ARP DVB_S2_ FEEDER DVB_S2_RcST FWD G MAC8021 8021le MAC8021 MACBO21 JEN Select Mode ES FIFO QoSAP MAC8023 80211 e I Wphy S FIFO MAC8023 8 An 802 11 e access point s protocol stack Summary This chapter introduces how to set up an 802 11 e QoS network The most important step for enabling 802 11 e QoS service is to specify QoS parameters The QoS parameters are based on IEEE 802 11 e specification A user needs to understand the meanings of these QoS parameters for achieving correct simulation results A user can easily develop and evaluate his her IEEE 802 11 e scheduling mechanism on NCTUns 120 17 Tactical and Active Mobile Ad Hoc Networks actical and active mobile ad hoc network MANET is characterized by network nodes that can move actively in response to the current condi tions of the environment In such a network each network node is equipped with a wire
291. paths on multi hop wireless networks The ETX metric wireless mesh network subnets can be viewed and managed incorporates the effects of link loss ratios asymmetry in the by executing the Menu gt N_ Tools gt 802 11 b Wireless loss ratios between the two directions of each link and Mesh Network gt Manage 802 11 b Wireless Mesh interference among the successive links of a path It Network Subnets command The following figure shows minimizes the expected total number of packet transmissions the dialog box of this command including retransmissions required to successfully deliver a packet to the destination The following figure shows this dialog box 116 Module Edit Parameters Setting Cancel The MeshOSPF module s parameter setting dialog box The following figures show the mesh STP access point s protocol stack and the MeshSW module s parameter setting dialog box Mesh STP access points use the spanning tree protocol to build up a routing tree among mesh access points This protocol is commonly used in switches on fixed networks to avoid packet looping problems WV Node Editor MAC8021 MAC8021 Wphy Wphy Ae Ae Select Mode pE C Summary This chapter shows how to set up a wireless mesh network on NCTUns Nowadays NCTUns provides two kinds of mesh access points which are designed to run OSPF routing protocol and spanning tree routing protocols respectively Mobile devices can move around a wi
292. pecific radio interface Before clicking the Modify button one has to choose one of the entries listed in the interface table to specify which interface he she intends to modify If one clicks the Modify button directly without specifying an interface entry by default the nctun sclient will invoke the dialog box of the first interface The following figure shows an example dialog box after one clicks the Modify button Mobile ID a j x gt Path Application Down time Interface Mobile IP Single hop cont z Yim Arrival time s Pause tim ID X m dd Modify Delete all Default moving speed to the next waypoint 110 000000 Insert a sequence of random waypoints until the Generate last point of the whole path exceeds Import a sequence of points from file Import Export the current moving path to file Export C P A N S T Node editor OK Setting Multi interface ITS Cars Insert Multi interface ITS Cars One can select the icon of the multi interface car Mp and then left click the mouse in the field to add a multi interface mobile node After one left clicks the mouse the following dialog box will be popped up for users to specify which type of and how many radio interfaces to be added into this multi interface car As introduced earlier NCTUns now supports eight different t
293. posely delay drop reorder real life packets while they are exchanged on the simulated link a user can put a WAN node on the link to achieve these effects External Ad hoc Mode Mobile Node For emulation an external ad hoc mode mobile node in the real world need not be a mobile device e g a notebook computer equipped with an IEEE 802 11 interface Actually it can be a fixed host which uses a normal Ethernet link to connect to the simulated network Because the external mobile node s IEEE 802 11 MAC protocol is simulated in the simulated network the IEEE 802 11 MAC protocol on the real life external mobile node is not used between the external mobile node and the simulation machine to exchange their packets In addition mobility is simulated by the simulator rather than by the user physically moving the external mobile device around the simulation machine For these reasons the external mobile device actually can be a fixed host The following figure shows an emulation example in which one external ad hoc mode mobile host communicates with a simulated mobile host via another simulated mobile host Initially the external mobile host on the left can exchange packets with the simulated mobile host on the right via the middle mobile host However as time proceeds the mobile host on the left begins to move away from the simulated mobile host not in the real world but in the simulated network and eventually it will be away from the tr
294. program to automatically assign IP and MAC tom DO Sete Lin D Yew tee UPR wo SHA vv vug try tae i SREB VSL LGAALSi_HMAABALASD PSE BENG Serer RBH ARARSRA SS OER P namma AA A D Il Pim ar a addresses to all GPRS phones saving much time and effort of the user The subnet ID of the GPRS subnet is automati cally assigned by the GUI program and can be known by moving the mouse cursor over the blue interface box on the left side of the GGSN see the above figure The formed GPRS wireless subnets can be viewed and managed by executing the Menu gt N_Tools gt GPRS Network gt Manage GPRS Subnets command The following figure shows the dialog box of this command ai q A Seiey Eee je oe j a g e a a ae gw At Sa see Li L AARAA OE RP a g ee oe E N ai mamm e A O H p l a a z In NCTUns the IP addresses assigned to GPRS phones can be viewed as public IP addresses in the simulated network Any host on the simulated fixed network can send packets to a GPRS phone using the phone s IP address as the desti nation IP addresses of these packets Likewise a GPRS phone can actively send its packets to any host on the simulated fixed network using the phone s IP address as the source IP addresses of these packets 97 Inserting Multiple Base Stations and Phones If a user wants to create and insert multiple GPRS phones into the working area in just one step the Menu gt N_ Tools gt G
295. r DiffServ parameters 105 Reference 1 RFC 2475 An Architecture for Differentiated Services 2 RFC 3246 An Expedited Forwarding PHB 3 RFC 2597 Assured Forwarding PHB Group 4 RFC 3140 Per Hop Behavior Identification Codes 106 of channels This parameter can also be set by executing the 14 Optical N et W orks Menu gt N_Setting gt Optical Network gt Set Optical Link Wavelength Channel Number command Once the O ptical networks are commonly used in the backbone first optical switch is added to the topology editor a user can of the Internet to provide long distance and large no longer change the value of this parameter bandwidth links This chapter illustrates how to use NCTUns to conduct simulations of optical networ ks which Optical Link Wavelength Channel Number include traditional circuit switching optical networks and Enter the number of warelength channels per optical link more advanced optical burst switching OBS networks eu Optical Network Concept The wavelength channels of an optical link are independent and can be individually configured A user can set the An optical network is composed of optical links optical switches and optical edge routers Optical edge routers are located at the boundary of an optical network They inter bandwidth signal propagation delay bit error rate and down time periods of a specific channel of an optical link When a i
296. r than the specified maximum number due to the deployment density limitation Car Profile Specification Each ITS car can be specified with different auto driving behaviors A driving behavior is defined by a car profile After inserting ITS cars one can specify what kind of profile should be applied to an ITS car This can be done by using e LContiguration ITS car interface type ITS car with an 80211 b infrastructure mode interface S car with an 802 11 b ad hoc mode interface Profile i eh 1 Edit Profile TS car with an 8021l p interface agent controlled S car with an 802 11 p interface module control led Profile z Edit Profile car with a GPRS radio S car with a DVB RCST Return Channel Satellite Terminal S car with an 802 1 amp e interface Profile 4 ly Edit Profile ITS car with all different interfaces Profile 3 Oj m Edit Frofile Profile 5 QO a Ian iia ees Edit Profile Average distance between two cars on the same lane T sry tr ee eee ea The maximum number of total deployed cars on the roads Generate the LHI prol 1 le mapping file Cancel the Menu gt N_Tools gt ITS Network gt Configure Cars cane profiles command in the Edit Property operating mode The following figure shows where this command is located When the Edit Profile button associated with a specific profile is clicked a vim editor will be executed and the file storing the correspond
297. r to previous chapters for their usages In the following we explain the usage of the IEEE 802 11 p Provider Setting tab in detail W IEEE 802 11 p RSU IEEE 802 11 p Provider Setting Application Mobile IP Name ROUTERS Provder Service Information Table Add Delete 143 Under the IEEE 802 11 p Provider Setting tab one can specify which services a RSU node intends to provide during simulation A service in an 802 11 p network is defined as broadcasting of messages for some specific objective e g road condition notification Clicking the Add button will pop up a dialog box for adding deleting an entry into from the provider service information table As shown in following figure a service information entry is composed of eight fields 1 Time 2 Action 3 Provider Service Identifier PSID 4 Priority 5 Service Channel ID 6 Provider Service Context PSC 7 WSA Repeats and 8 WSA Persistence The Time field indicates when this service information entry will be processed by this 802 11 p provider node during simulation the Action field specifies which action should be taken by this provider when the simulation clock advances to the time specifed in the time field NCTUns now supports two actions add a service and delete a service the PSID field denotes the numerical identifier of this service The Priority field specifies the priority level of this service A higher value of thi
298. rame These frames are represented by the black blocks and the gray blocks respectively in the above figure In the draft standard 5 it is suggested that the duration of a frame either a control or a service frame is set to 50 milliseconds A footnote in the draft standard states that this value may be adjusted in the future standard showing that different values may be used for different applications In a transmission cycle the control frame must be on CCH whereas the service frame can be on a specific SCH The 802 11 p standard divides network nodes into two types One is the 802 11 p on board unit OBU which represents a vehicle equipped with a DSRC Dedicated Short Range Communications radio the other is the 802 11 p road side unit RSU which represents a fixed device with a DSRC radio mounted on road sides The operation of this new network type is briefly explained below After attaching to an IEEE 802 11 p 1609 network an OBU node should first operate on CCH to gather necessary network information In the WAVE mode data packet trans missions are only allowed to occur within a Wave mode Basic Service Set WBSS A node that initiates a WBSS is called a WBSS provider and nodes that join a WBSS are called WBSS users To establish a WBSS a WBSS provider has to periodically broadcast a Wave mode Service Announcement WSA Frame for this WBSS on CCH A WSA includes the opera tional information of a WBSS e g the I
299. rection 6 amp Convaktion cendna PSr The period of a slot is 0 logota ms The period of a frome is 1 00000 ms The penod of a supenrame is 10ITOMC ms Node motor Ce The automatically generated central frequency of each channel is displayed on the tab of Return link frequency which is shown below Each time when one changes the central frequency of the whole uplink downlink frequency band or the channel bandwidth one should click the Show Frequency button on this tab to re calculate the central frequency of each channel The resulting values will be shown on this tab Aeran link arangie Growing Arum ink capacny Antum ink frequency Pore ink orrinpemneni Uplink central regency Shaw Proquancy thannig central frequency G 3097210051 1 SSS Lode E piale iay ra 4 SIDI SIS ja A202 PAL BS Dawalink central requerey Channel central frequency 5 289 7 719148H 20S 04 TH999 99 Fa al e901 90nd 20027017408 to 4 p Aide edig rt Cancel Return link Channel Framing According to the DVB RCS standard 1 the time domain of each channel on the return link is divided into consecutive superframes In turn each superframe is divided into frames Finally each frame is divided into timeslots The following figure shows the framing structure applied on a return link channel Frequency Superframe Superframes frames and timeslots on a return link channel Like what is shown in the fol
300. reless mesh network and use the mesh infrastructure to communicate with each other or connect to the Internet A mesh multi gateway switch should be employed to act as a bridge between a wireless mesh network and other fixed networks In this mesh simulation environment new mesh routing protocols and new mesh network applications can be developed and evaluated 117 gt Module Edit Parameters Settinn Flush Time Interval s000 ms Cancel rT Spanning Tree Prot Hello Time f sec Max Age 2 sec Forward Delay f 2 ms C Build Switch Table In Advance t Be careful Mobile nodes addresses are not include packets will not be forwear this switch J Show Switch Table File Name 6B2 sw_N2 smt Run Time Query Switch Table The MeshSW module s parameter setting dialog box 16 IEEE 802 11 e QoS Networks ireless LANs WLAN provides the same best W effort service as that provided on Ethernet Although this service is good enough for data applications it is inadequate for multimedia applications that demand quality of service QoS In order to provide service differentiations and QoS guarantees on WLAN the IEEE 802 11 committee developed 802 11 e specification This chapter presents how to use NCTUns to simulate EEE 802 11 e QoS networks IEEE 802 11 e Concept The 802 11 e specification defines MAC protocols for QoS enhancements under the infrastructure mode An access point allocates medium access opportuni
301. respectively In this physical network configu ration one switch connects the subnets 192 168 1 1 and 192 168 1 2 and the other connects the subnets 192 168 2 1 and 192 168 2 2 Note that one MUST NOT use only one switch to connect all emulation machines together for such a network Otherwise the emulation machine that emulates the middle part of the network will not work correctly and 72 External Router ID g 192 168 2 1 192 168 4 1 192 168 3 1 192 168 4 1 Emulation Machine 192 168 1 1 Emulation Machine tm 192 168 1 2 192 168 2 1 Switch Emulation Machine wd 192 168 2 2 Switch In this example the dispatcher program and the GUI program are run on the emulation machine with the IP address 192 168 1 1 One should properly set the DISPATCHER_IP parameter of the coordinator cfg file for each involved coordinator program In this example the DISPATCHER_IP should be set to 192 168 1 1 on each emulation machine so that each coordinator program will register itself with the same dispatcher program After this is done one should run up all coordinator programs on their respective emulation machines One then runs up the GUI program to draw the topology and set up the traffic One should set the Dispatcher IP address for the GUI program in the Menu gt G setting gt Dispatcher panel After finishing specifying the topology one should double click the icon of the
302. rking field is that the coordinate system used by the QT library which is used by the GUI program to display a network topology uses a coordinate system with the origin 0 0 at the top left corner The simplest way to convert this coordinate system to a common Cartesian coordinate system is mapping it onto the fourth quadrant of the common Cartesian coordinate system with the origin 0 0 on the bottom left corner Based on this coordinate system the polar coordinate system corresponding to it from a node s perspective is shown as follows A co 180 a 210 86 NCTUns uses this polar coordinate system to denote the antenna pointing direction of a node In this polar coordinates the horizontal line passing through the node itself towards the right denotes the zero degree direction while that passing through the node towards the left denotes the 180 degree direction On the other hand the vertical line passing through the node towards the top denotes the 90 degree direction while that passing through the node towards the bottom denotes the 270 degree direction In the following we use two examples to illustrate how the directivity of an antenna is represented in NCTUns As one can see in the following figure where there is an 802 11 b mobile node equipped with a 120 degree directional antenna Suppose that the node is now pointing its antenna towards the 90 degree direction Using this setting the antenna of this mobile
303. road map represents a road using only lines before loading a road map one has to determine the number of lanes on a road in both directions and the width of each lane The dialog box is shown as follows Road Property Number of lanes on a road in both dirdal E 3 4 meter Cancel After loading a road map the GUI program will convert it to the road network structures used by NCTUns One can use the Select an Area to Save As Shape File iZ tool to clip off a smaller road network to suit his her own needs To clip off a road network one first clicks the icon of this tool presses the left button of the mouse and then drag the mouse to draw a colored rectangle area on the working area After selecting the area to be clipped one can release the left button of the mouse to end the clipping procedure A dialog box will be popped up to help the user save the clipped road network Lane width 4 p Tee pi Tia G Dm h ety i yen pip a Ce een Te a Haan eM BERR rolada bA d 2 aa Psa ke wa Bebe S tr me AARAA oc eo ERP Immo n pe ee oe T t The Era fH ITS Car Insertion and Placement Six different types of ITS cars are provided in the current implementation and they are shown from left to right in the following figure I car with an 802 11 b Infrastructure mode interface A car with an 802 11 b ad hoc mode interface G car with a GPRS radio R car with a RCST satellite interface
304. rol messages and data transmitted by these nodes are likely to collide with each other at the NT MS This will make the NT MS fail to receive control messages necessary for its network operation As a result the NT MS may not be able to receive any data from its NT MR BS and NT RSs when it is located within the overlapping area of their signal coverages Is N Tools G Setting N Setting Simulation View Help YF nlloagseoyvysyvuwpg 9e TIA Ee QA D ER P s s Pr hee a A PL ahd my sy a A fe id 2 et gga J sart a L a r aag See was pa E Md TY P S Pi ba Py eee eee aks Steeeeen renee 000 000 000 000 C Node ID 1 Summary In this chapter we conceptually introduce the IEEE 802 16 j network and present the steps required to configure a network case of this new network type over NCTUns In addition several useful commands and important dialog boxes for this type of network are also explained 166
305. rom an existing mpt file Each line in an mpt file represents a waypoint and its format is X_pos Y_pos Arrival Time Pause Time Moving Speed This file may be generated by a program e g a vehicle microscopic traffic simulator or as a result of exporting a mobile node s moving path In the topology editor a user can also drag and drop the mouse to directly place a path s waypoints Under the Single hop connectivity tab the GUI program will calculate and show at what time this mobile node can cannot reach other mobile nodes in its single hop trans mission range On the other hand under the Multi hop connectivity tab the GUI program will calculate and show at what time this mobile node can cannot reach other mobile nodes via multiple hops through the help of the ad doc mode forwarding These two functions are provided for comparing research results with the ideal results The outputs of these two functions represent the most accurate and ideal routing paths that only God can know and achieve at any time These two functions are meaningful only when the used wireless module is the simple WPHY which has a specific trans mission range and is not very realistic When the used wireless module is the advanced AWPHY which does not have a clear transmission range but is more realistic the two connectivity functions are not very meaningful Under the Interface tab a user can examine the interface s attributes
306. rossroad ais and ITS road merger ITS Road Side Unit RSU with an 802 11 p interface Pa The second group is about ITS cars that run on a constructed road network which includes ITS car with an 802 11 b infrastructure mode interface K ITS car with an 802 11 b ad hoc mode interface 8 ITS car with a GPRS radio ITS car with a DVB RCST satellite interface B ITS car with an 802 16 e interface ga ITS OBU with an 802 11 p interface agent controlled ER ITS OBU with an 802 11 p interface module controlled ED and ITS car with all of the above different interfaces ND The functions of these icons will be explained in a later chapter for ITS wireless vehicular networks A user can choose a device by clicking the mouse s left button on its icon on the tool bar He she then moves the mouse cursor to a location in the working area and then clicks again to place the chosen device at the current position of the cursor A network topology consists of not only nodes but also links between them Links can be added to the network topology easily A user can click the link icon move the cursor to one device node click the device node to fix one end of the link drag the link to another device node and then release the mouse button to fix the other end of the link The user will see that a straight line between the two selected nodes is created The following figure shows the network topology after the user has placed several
307. router NCTUns supports distributed emulation of a large network over multiple machines If the load of an emulation case is too heavy so that it cannot be carried out in real time on a single machine this approach can simultaneously use the CPU cycles and main memory of multiple machines to carry out a heavy emulation case in real time More information about this useful feature is available in a later chapter named Distributed Emulation High Simulation Speeds and Repeatable Simulation Results NCTUns combines the kernel re entering simulation methodology with the discrete event simulation method ology As a result it executes simulations quickly NCTUns modifies the process scheduler of the Linux kernel to accurately control the execution order of the simulation engine process and all involved real life application processes If the same random number seed is used for a simulation case the simulation results are repeatable across different runs Support for Various Important Networks NCTUns simulates Ethernet based IP networks with fixed nodes and point to point links It simulates IEEE 802 11 a b wireless LAN networks including both the ad hoc and infrastructure modes It simulates GPRS cellular networks It simulates optical networks including traditional circuit switching optical network and more advanced optical burst switching OBS networks It simulates IEEE 802 11 b wireless mesh networks EEE 802 11 e QoS ne
308. rs in 2009 Distributed Emulation istributed emulation is a novel methodology that allows multiple machines to cooperatively conduct an emulation case By using this methodology the system resource e g CPU cycles and main memory required to run an emulation case can come from multiple machines which greatly increases the scalability of emula tions over NCTUns In this chapter we present in detail how to use NCTUns to conduct an emulation case on multiple machines using the distributed emulation methodology Advantages and Concepts Network emulation is an approach that enables real world devices to interact with a network simulated in real time Most existing network emulators abstract a complex simulated network as a single router They use a machine to simulate such a router in real time and connect it to real world devices The packets generated by the real world devices are directed to the router When these packets enter the router the router gives them special treatments such as dropping delaying or reordering to simulate the bahavior of the original complex network By this approach one can evaluate the functions and performances of a real world device under various simulated network conditions NCTUns seamlessly integrates simulation and emulation to provide unique advantages over most existing network emulators Ina NCTUns emulation the network simulated in real time need not be abstracted as a single router wit
309. rsity and the complexity of various tactical policies integrating such policies into the simulation engine will complicate the design of the simulation engine and make it unmanageable To overcome this problem NCTUns uses the following design principles to support tactical and active MANET simulations 121 In NCTUns the tactical policy is separated from the under lying mechanism A user level program referred to as a tactical agent program is responsible for making tactical decisions and controlling the behavior of the mobile node on which the agent is running The simulation engine is respon sible for providing agents with essential services such as obtaining the current position of a node on which an agent is running agent to agent communication and so forth Simulation related files obs and sce files Agent program 2 Tactic API 44 functions A Moria sacked Interface logic Namal socked Inferlace System call service routines Fer tactic agent Tunnel device Tunnel device pregrams i l The architecture of NCTUns for supporting tactical and active MANET simulations In the above figure the agent logic contains the core state ments of an agent program It performs some specific tasks such as making a strategy based on the current conditions of the battlefield The tactical API functions have to be included in an agent program to provide the agent logic with the es
310. rved and used for the ad hoc subnet formed by these ad hoc mode mobile nodes In such a case the subnet number used for fixed subnets will start from 2 On the other hand if there is no ad hoc mode mobile node in the network the subnet number used for fixed subnets will start from 1 The GUI program can automatically generate and assign IP addresses to ad hoc mode mobile nodes ga or ub hosts and routers on the fixed network For infrastructure mode mobile nodes ag or by however the GUI program needs helps from the form subnet s tool to automatically generate and assign IP addresses to them The full name and location of this tool are shown in the following figure More information on the usage of this tool will be presented in a later chapter Fle Ede gT pH Toe 0 Bais f_Getieg Sjeutsieon few Hep are a Se ee ee oe Sy ewe po Pew ea ae BeBe F sotect wir roles naden fo fore a gubsoet click on tha r right t button to and the selection m BeSbOeereh BERS AAKER DER P a har gt aan 7 bg gmj 0 00 00 000 O00 e a Gute Gorn 0 it 069 GH 209 ae a T n gia wi The reason is that an infrastructure mode mobile node needs to use an access point to connect itself to the fixed network To successfully send and receive packets to and from the fixed network the infrastructure mode mobile node needs to use an IP address whose subnet ID is the ID of the subnet that the access point belongs to
311. s By allocating a link s wavelength light channel only for the duration of a burst and statistically sharing the link among bursts belonging to different traffic flows it provides a better link utilization than the static circuit switching technology Although the OBS technology provides a higher link utili zation than circuit wavelength switching technology its performance is not satisfactory Due to the optical switch s bufferless property when multiple bursts contend for the same link at about the same time only one burst can be successfully switched in the optical domain and all other overlapping bursts need to be dropped This results in low link utilizations and high burst loss rates Some existing contention resolution schemes for photonics packet networks such as fiber delay lines FDLs and deflection routing may be used in optical burst switching these methods have their own drawbacks For FDLs they are costly and their buffering capability is limited For deflection routing packets may be and thus lowering a TCP connection s achievable throughput Another method is to use multiple wavelength channels and convert a burst s networks However transported out of order wavelength to another wavelength when there is a burst collision However optical wavelength conversion is costly In the original design when two bursts collide the second burst is discarded entirely Apparently this design is ineffi ci
312. s a result a user may experience some delay up to a few minutes depending on the machine s speed without any progress update on the screen At this moment the user needs to be patient These files include a packet animation trace file and all performance log files that the user specified to generate Generating these performance log files can be specified by checking some output options in some protocol modules e g 802 3 or 802 11 b protocol modules in the node editor In addition application programs can generate their own data log files For example the pre installed rtg program can be specified to output a performance log file showing the end to end delays experienced by all received packets The packet animation trace file can be replayed later by the packet animation player The performance curve of these log files can be plotted by the performance monitor Details about the animation player and the performance monitor will be explained in later chapters For this simple case the packet animation trace file is named test ptr which uses the main file name of the topology file test tpl The ptr file is a logged packet transfer trace file Its animation can be played by the animation player at a specified speed To save disk space and transfer time the ptr is a binary file which means that its content cannot be directly viewed using a normal text editor such as vi or emacs To allow a user to convert it
313. s attribute means that the service has a higher priority for OBUs to receive For example when several services that an OBU x has subscribed to are broad casting their messages on the control channel the OBU x should listen to the messages broadcast by the service with the highest priority level The Service Channel ID field specifies the ID of the service channel that this service uses The allowed service channel IDs are 174 175 176 180 181 and 182 The PSC field denotes the name of this service which can be any arbitrary ASCII string The WSA Repeats field denotes the number of WSAs that should be repeatedly sent within a control frame To be precise the WSA Repeats 1 is the number of WSA occurrences within a control frame Note WSA is an action frame with capability information elements and contains additional fields that describe the provider information needed by the potential service users WSAs are sent by its service provider on the CCH Finally the WSA Persistence field indicates whether the provider will periodically transmit WSAs on each CCH frame If this value is set to True the provider will transmit WSA_REPEATS 1 WSAs on every CCH frame Otherwise it only transmits WSA_REPEATS 1 WSAs on the first CCH frame when forming a WBSS Service Information Record Time Action Provider Service Identifier PSID Priority service Channel ID Provider Service Context PSC WSA Repeats WSA P
314. s eoyveyvuug CELLE Fae G BORN rreja Laii SATA ALS fF sa eee BeSbSeerste bE ASS Gea DERP 7 Er rae ae db Ul E hir Be E ey Receiving Node Perspective If the Use the receiving node perspective mode is chosen the GUI program will show the maximum range that a node X can interfere with the chosen node where node X denotes the set of nodes in the network other than the chosen node itself In addition if a node X can interfere with the chosen node using the current setting Such setting includes the two nodes current antenna settings the distance between them and the existence of obstacles on their line of sight path etc the GUI program will draw a red colored dotted arrow C gt from node X to the chosen node indicating that if the current setting is adopted the trans mission activity of node X can be sensed by the chosen node and may block the receiving activity of the chosen node The following figure shows a snapshot when the Use the receiving node perspective mode is used 78 fie Gea g Tadi Too TT aj p Benay Seuumcn jew He XAOS Ewa eevee yu geeuszi ia SOMO ress LLOLL Oe SA ASALOY Sa beh BeBBSMETEE BER AARAA 2 DERP Ls a H AQ MP Il mhg a 0 m HHH ii im en Bag ood Ea Dae Bo BOS ee Shoe im eroa Fare Node Connectivity Determination When the Use the receiving node perspective mode is used one can further choose the way that the GUI progra
315. s generated by these devices the NCTUns emulation machine may fail to process these packets in real time In such a case the emulation fails to be an emulation The third problem is that under a heavy load condition even though the NCTUns emulation machine can barely run the emulated network in real time the synchronization between its simulation clock and the real world clock will become less accurate This may cause the real world packets exchanged over the emulated network to experience unnec essary extra delays or losses The fourth problem is that when many applications need to be run up on the emulated network the NCTUns emulation machine may not have enough main memory to run up all of these applications To overcome these problems NCTUns provides a distributed emulation approach By this approach a large emulated network is divided into several smaller parts and each part is run by a NCTUns emulation machine Each NCTUns emulation machine just needs to 1 emulate the nodes and links in its assigned part 2 run the real world applications that should be run up on these nodes 3 exchange real world packets between it and the real world devices that are attached to some nodes in its assigned part and 4 exchange packets with other NCTUns emulation machines when these packets need to traverse into other parts By properly dividing a large emulated network into several smaller parts such that each part can be emulated by
316. s of packet logs generated on different emulation machines may not accurately reflect the order of their occur rence in the real world As a result when they are merged together and played back on the packet animation player the causal order of their appearance may be wrong Another 73 Virtual Router 2a External Router ID f C Use a real router to connect multiple emulation n Let multiple emulation machines communicate with each other di Port ID Assigned IP addre d Coordinator IP address Emulation Machine IP address used 1 0 2 3 192 168 1 2 192 168 2 1 2 1 0 3 1 192 168 2 2 192 168 2 2 Edt Node editor Cancel problem is that this approach does not support the migration of a mobile node from one emulation machine to another It is suggested that when one is designing how to partition a network for distributed emulation one should choose a partition in which mobile nodes need not move from one part to another part of the emulated network To reduce the timing differencse among all involved emulation machines it is recommended to synchronize the system clock of each emulation machine and those of the machines running the GUI dispatcher and coordinator programs Before a distributed emulation case runs the GUI program will send each coordinator program a control message to notify it of the time on which the emulation case should be started If the system clocks of all involved
317. sed to calculate the rain fade MV Module Edit ax GW Parameters Setting Ground Station Antenna Length im eee OK J Default Ground Station Antenna Efficiency 0 68 Cancel Rain Fade 20 X Link Failure User Defined See Down Time Setting Antenna Angle 89 degree File Name cs Dvb_rcs_gw_N3_PLlinkfail Polarization o degree 0 for horizontal polarization 45 for circular polarization 90 for vertical polarization Rain Height 31 km Earth Station Height 0 07 ikm Latitude 24 degree Rain Rate 50 rmjh Summary In this chapter we describe the usage of DVB RCS networks on NCTUns The content includes the network construction the channel resource allocation the RCST QoS packet scheduling the rain fade effect etc One can follow the described steps to set up a DVB RCS network in the GUI environment Reference 1 ETSI EN 301 790 v1 4 1 Digital Video Broadcasting DVB Interaction channel for satellite distribution systems Sept 2005 137 19 IEEE 802 11 p Networks I mances of CSMA CA based networks in vehicular environments This new specification is also called the WAVE mode which denotes the Wireless Access in the Vehicular Environment for the 802 11 network family and standardizes the next generation Intelligent Transportation System ITS network In this chapter we first briefly explain the notions of an ITS
318. sed to select two infrastructure mode mobile nodes and one access point to form a wireless subnet ilo aeey fiery insem ee jj Te RE ewe eee ev wag aaa a The chuwo oe ce he DERP KA CE f Fror 2 ES a S 3 fj SEE RBHRSSs BEY a a oe Ball N a 2G ria a 4 A user must be aware that if he she switches the mode back to the Draw Topology mode when he she again switches the mode back to the Edit Property mode nodes IP and MAC addresses will be re generated and assigned to layer 3 interfaces Therefore the application programs traffic generator now may use wrong IP addresses to communicate with their partners In this mode since the IP and MAC addresses and the port ID of an interface have been automatically generated and assigned the GUI will automatically show these information 12 when a user moves the mouse cursor and place it over the blue interface box on the screen for a while This can conve niently let the user see the results of these assignments In addition to automatically generating IP and MAC addresses the GUI program also automatically and silently performs many tasks for the user Many of these tasks are performed underground to automatically correct a user s configuration mistakes This is to avoid generating wrong simulation results and causing simulation crashes For example the GUI program will automatically set the promiscuous mode of the 8
319. sential services According to the purposes of these tactical API functions the tactical API functions can be categorized into five different groups each of which is repre sented by a numbered arrow in the above figure The detailed explanations of these API functions are available in The Protocol Developer Manual for the NCTUns 6 0 Network Simulator and Emulator document The Simulation Field and Mobile Node The field of a simulation is the space within which mobile nodes are allowed to move around A battlefield is defined as an area within which members of forces such as soldiers tanks etc can move to perform military operations As such the field of a simulation can be viewed as the battlefield of a campaign and the members of forces can be viewed as mobile nodes moving on the simulation field The field is usually defined by a rectangle specified by its length and width As shown in the following figure under the Simulation tab which is in Menu gt G Setting gt Simulation the attributes of the simulation field can be specified simulation 09 GDE Debug System a 4 ir Simulation Speed Simulation time E Te n A Fe i Generate packet animation log file ptr Fixed Inbernet IM Wireless LAN IM GPRS network jal Optical network Wildax network MobileWiMax network IM MobileRelayWidMax network transparent mode jl MobileRelayWidMax network non tr
320. ser uses the package s default settings A user first downloads the package from the web site at http NSL csie nctu edu tw nctuns html Starting from the 2 0 version the operating systems that NCTUns supports is only Linux and FreeBSD is no longer supported Right now the Linux distribution supported is Red Hat s Fedora 11 which uses Linux kernel version 2 6 28 9 After reading the installation explanations and instructions INSTALL README FAQ KNOWN PROBLEM RELEASE NOTE and running the installation script install sh a directory named nctuns will be created in the usr local directory which in turn has several subdirectories 99 66 The name of these subdirectories are bin etc tools BMP and lib respectively In the following we explain each of these subdirectories briefly 1 usr local nctuns bin This directory stores executable programs of the GUI program dispatcher coordinator and the simulation engine 99 66 Their names are nctunsclient dispatcher coordinator and nctunsse respectively 2 usr local nctuns tools This directory stores executable programs of various appli cations and tools pre installed by NCTUns For example rtcp ttep tcpdump stg rtg and ping are supported Some daemon programs used by 29 66 29 66 99 66 99 66 currently step ripd ospfd 29 66s nctunstc
321. settings of optical networks They are located in Menu gt N_Setting gt Optical Network Set Optical Link Wavelength Channel Number In a WDM optical network an optical link usually have multiple channels using different wavelengths In NCTUns all optical links in a WDM optical network must have the same number of channels This command sets the number of channels per optical link The default number is 3 If a user wants to use a different number he she must execute this command to change the setting before adding any optical link to the topology editor Executing this command after an optical link is added is not allowed F I a Optical Link Wavelength Channel Number Set Optical Link Packet Playback Channel s Like a packet transfer animation played on a fixed network packets transmitted on an optical network can be played to show their movements on optical links Since a WDM optical link has multiple channels and a user may be inter ested in seeing packets flowing on only one several or all channels of a link this command is provided for a user to select which channels packets should be displayed A Please select the channel s on which packets should be displayed All channels Multiple channels e g 1 3 4 Set Optical Link Packet Playback Color Like the channel color settings for packet playback on WLAN and GPRS networks this command is provided to se
322. sh script tsetenv ifconfig NCTUns are also stored in this directory For example the daemon programs used for emulation and Mobile IP are stored here The agent programs that are used for tactical and active mobile ad hoc network simulations e g Magent1 are also stored here These tactical agent programs can be run on mobile nodes to control the moving behavior of mobile nodes Due to the use of a novel kernel reentering simulation methodology NCTUns has two advantages as follows 1 Any real life application program can be run on a simulated network to generate traffic and 2 Their performance can be evaluated under different simulated network conditions Thus the real life application programs pre installed in this directory represent only a very small subset of real life appli cation programs that can be used with NCTUns During simulation if a user wants the simulation engine to run up an application program that is not pre installed in this subdirectory e g the P2P BitTorrent program the user must first copy that program into this subdirectory e usr local nctuns tools so that the simulation engine can find it during simulation Detailed information on how to specify which application programs should be run on which nodes in the GUI program is presented in the Topology Editor chapter 3 usr local nctuns etc This directory stores the configuration files needed by the dispatcher and co
323. should carefully calculate and determine the uplink sustained rate of each NT MS in a simulation case Before starting the simulation one should specify the QoS provision setting for each NT MS node using the Set Qos Provision for Mobile Stations command The path of this command is shown as follows Menu gt N_Setting gt 802 16 j Network gt Non transparent Mode gt Set Qos Provision for Mobile Stations The following figure shows the screenshot of this tool When using this tool one is required to enter the Node ID of the specified NT MS and the desired uplink sustained rate in Kbps for the specified NT MS Set Mobile IP For Non transparent Mobile Relay Base Stations and Non transparent Mobile Station The procedures to configure the Mobile IP settings for NT MSs and NT MR BSs are the same as those for T MSs and TMR BSs Readers can refer to the previous section Set Mobile IP For Transparent Mobile Relay Base Station and Transparent Mobile Station for detailed information 165 Setting of Physical Layer Parameters for IEEE 802 16 j Non transparent Nodes The settings of IEEE 802 16 related protocol modules can be specified via the Node Editor Readers can refer to the previous section IEEE 802 160 Protocol Stack for detailed information The following figure shows the default settings of the physical layer parameters for an IEEE 802 160 non transparent mode node One may need to change the def
324. sing a large value can allow the whole network to be clearly shown on the screen without using the Zoom Out function Although the user can use the default value 1 e 1 and the Zoom Out function to display the whole network topology on the screen node icons will become too tiny to be seen on the screen and it will be very difficult for the user to manipulate these tiny icons e g to select them Under the System command tab to be executed system commands and their output file names can be specified here A system command is a command that when executed will get or set an object s value at the specified time The output of the command will be saved to the specified output file which will later be transferred back to the GUI program when the simulation is finished In addition to getting setting a single object s value the values of all objects of the same kind can be get or set at the same time to take a global snapshot of the whole network For example this function can be used to take the snapshot of the current routing tables of all routers This global snapshot information can help a researcher study the conver gence of a protocol Time the starting time for executing this command Command the system command string Output file name the name of the output file The system commands provided by NCTUns are listed below Their syntax and meanings are also explained below Set set a value to a variable in a mo
325. small as possible BW As high as possible Provide the IP Address of the external host here Simulation Machine Add a routing entry here External Host Example 2 The following figure shows the second example In this figure two external hosts are connected to the simulated network The right external host connects itself to the simulated switch while the left one connects itself to the simulated router The two external hosts want to exchange their TCP packets via the simulated network Suppose that the IP address assigned to the left external host is 1 0 1 1 and the IP address assigned to the right external host is 1 0 2 1 A ae Fo Das fd Ge ji iw D g 6 rg Ee Fee jj lt A oe ea Ee E ETTET ae gs eae a fj S ER E L EERSTE RE a a e e E n BOGE SRESE P BEY ARAS es SIDER P 3 ia 3 sf ee AL A e a o coe af ted 00M OM OM os on a oe ie Faas T Suppose that the left external host wants to make a greedy TCP connection to the right external host In such a case the rtcp p 8000 command should be first run up on the right external host Then the GUI user can start running the emulation The GUI user can then execute the stcp p 8000 1 0 2 1 command on the left external host to run up the TCP sending program If the two external hosts are physically connected to the simulation machine and their routing 58 configurations have been properly set their TCP packets will
326. smitted on a 1 Gbps link it is better to use a smaller value for this parameter to see them 48 The default value for this parameter is 100 Other values such as 200 and 50 are provided If the ratio of the selected value to the default value is X the used time advancement quantity will be X times of the default time quantity If the playback clock is not advancing the time knot can be dragged to any location to jump directly to a desired time The following figure shows the time bar 000 0 e 535 oon 000 000 000 000 RRRA NARRATA AO EAAS RASAT NAAA ETASAN Fone fr Foe FSCO Fuad RERS NY FFT Soe r 100 000 000 000 If the user knows the exact time where the playback clock should directly jump to he she can double click the clock display area at the left to enter the time The unit of the entered time should be in tick and the relationship between a tick and its duration in virtual time is specified in Menu gt G_Setting gt Simulation s Speed tab This function is particularly useful when the user has used the printPtr utility program to read the ptr packet trace file and wants to jump the clock directly to a specific time to see the packet transfer activities occurring at that moment The following shows the dialog box of this function Di Jump the time directly to the time specified below in tick OK Cancel _ Animation Effects Wired network and wireless network hav
327. so that packets origi nated from the simulated network can be redirected back to the simulated network The rules for generating these routing entries are as follows For every host with 1 0 X Y as its assigned IP address in the simulated network we need to use the following commands to add the needed routing entries 61 1 route add 200 Z X Y interface NICNAME or route add 200 Z X Y GatewayIPaddress on FreeBSD 2 route add 200 Z X Y dev NICNAME or route add 200 Z X Y gw GatewayIPaddress on Linux Here Z is a variable taken from the set of all subnet IDs used in the simulated network NICNAME is the name of the interface on the external router e g fxpO or ethO and GatewayIPaddress is the IP address of the interface on the simulation machine to which the external router would like to send packets with 200 Z X Y as their destination IP address Note that 200 must be used because the emulation kernel module changes the destination IP address of a packet e g 1 0 X Y going to the real router to 200 0 X Y so that the packet can be recognized by the router and be sent back by the external router to the simulated network correctly Beside changing the first number of the destination IP address from the default 1 to 200 the emulation kernel module also changes the second number of the destination IP address from the default 0 to the ID of the subnet where the packet leaves the simu
328. ssfully find and execute it If the GUI user also wants the usage information of this new program to be displayed in the above program usage window he she needs to edit the usr local nctuns etc app xml file and put program into 14 the program s usage information into that file The format of this file is easy to understand The following figure shows the content of the usr local nctuns etc app xml file The content of the program usage information file app xml Running the simulation When a user finishes editing the properties of network nodes and specifying application programs to be executed during a simulation he she can start to run the simulation To do so the user must switch the mode explicitly from Edit Property to Run Simulation Entering this mode indicates that no more changes can should be made to the simulation case which is reasonable The simulation is about to be started At this moment of course no settings should be changed When the mode is switched to the Run Simulation mode the GUI will export many simulation files that collectively describe the simulation case These simulation files will be transferred to the either remote or local simulation server for it to execute the simulation These files are stored in the mainFileName sim directory where mainFileName is the name of this simulation case For example suppose that the topology file is named test tpl
329. st use the same bandwidth one has to specify the link bandwidth used by the ports of the hub in the Bandwidth field Router Router ID Name ROUTER Routing Down time Application Mobile IP Intra domain routing table Run time query how routing tabl O Run routing daem h005e Show ommand consol Node editor OK Cancel In this dialog box a user can specify whether all routers in a case should run routing daemons e g RIP OSPF to construct their routing tables or their routing tables should be calculated in advance by the GUI program Run time routing table content lookup can be performed by clicking the Show routing table button when a simulation is running e Switch D amp x Switch ID Down time Start s End s Add Delete Node editor OK Cancel e Access Point amp x AP property Wireless interface 802 11 a AP ID l Down time Start s Node editor OK Cancel Under the AP Property tab a user can set the down time periods for an access point x AP property Wireless interface Wireless Interface He Frequency Range ee Mode 1 0 000000 Infra enaren Node editor OK Cancel Under the Wireless Interface tab a user can examine the interface s attributes e g the used frequency channel and the wireless signal
330. t In such devices dialog boxes there is an Application tab in which a user can specify the commands for launching the desired application programs For example suppose that a user wants to sets up a greedy TCP connection between two nodes He she can specify the command rtcp p 8000 on the receiving node s Application tab and specify the command stcp p 8000 1 0 1 2 on the sending node s Application tab In this case stcp and rtcp are the pre installed real life application programs that will greedily send and receive TCP data respectively Also we assume that the receiving node has an assigned IP address of 1 0 1 2 and the rtcp program binds its receiving socket to port 8000 From the above example one sees that the specified commands are exactly the same as what a user would type into a UNIX terminal to launch run up these application programs The App Usage button in the following dialog box provides command usage information for each pre installed application program When a GUI user double clicks this button a program usage information window will pop up showing the detailed usage for each pre installed application Router ID B Name ROUTERS J Routing Down time Application Mobile IP Start tir Stop tin Commat Input file name Add Modify Delete pp Usag ommand consol Node editor OK Cancel
331. t the color scheme for packet playback over different channels of a WDM optical link Set Maximum OBS Control Packet Processing Time The usage of this parameter for optical burst switching networks will be explained in a later chapter about optical networks Setting the Background Graph Sometimes placing a background graph on the network topology working area can provide a great value For example when a user studies how to place wireless access points or base stations in a city to achieve the optimal perfor mance utilization coverage it is much better if the user can place the city map on the working area as the background graph Commands related to the background graph function are located in Menu gt G_ Setting gt Background Graph Paste Background Graph This command selects a bmp file and pastes it as the background graph In the following we use an ITS Intelligent Transportation Systems simulation case as an example and paste a map of the HsinChu city in Taiwan on the working area Position Background Graph After pasting the background graph the user can place the graph at any place 1 e shift its top left corner by an offset vector on the working area and specify its scaling factor 1 e enlarge it or shrink it 34 Look in ayexa mples Demo16_Backgrou ndGraph ec EE E 6 Demol6 BackgroundGraph sim O Demo16_BackgroundGraph mdt O Demo16_BackgroundGraph readme O Demo16 Backgro
332. t the shown group ID should be mapped to Group IO 1 Channel Capacity Assignment As mentioned before the maximum capacity of each return link channel is determined by the parameters entered into the dialog box of the tab of Return link arrangement The tab can be popped up by double clicking the NCC node The channel capacity can be allocated to every group of RCSTs that is assigned to use the transmission capacity of the channel In other words the total capacity of a given channel can be allocated to all RCSTs that issues receives signals on the channel The channel capacity assignment can be operated on the tab of Return link capacity which can be popped up by double clicking the NCC node As mentioned before each channel s maximum transmission capacity is shown on the top of the tab One can refer to the maximum channel capacity when starting to assign a certain amount of capacity to each RCST To start RCST capacity assignment one has to click the RCST Capacity Assignment button Made adig ov The following figure shows the popped up dialog box when clicking the RCST Capacity Assignment button In this box the remaining capacity of each channel is shown The remaining capacity is the channel capacity that can still be 130 allocated to RCSTs After choosing one superframe channel ID one can click the Set RCST Capacity button to allocate capacity to every RCST issuing receiving signals on the selected chann
333. t to be dropped However only when the current queue length is greater than ts2 will AF12 packets start to be dropped The MPR field specifies the maximum packet drop rate for AF12 packets Its default value is 80 The relationship between these parameters is illustrated in the following figure Packet drop rate maxqlen DiffServ Protocol Stack In the following figure the protocol stack of the DiffServ boundary router is shown In the protocol stack of the interface that connects the boundary router to an interior router a DS_TC and a DS_I protocol modules are used The former module deals with traffic classification and condi tioning while the latter module deals with packet scheduling In the following figure the protocol stack of the DiffServ interior router is shown In the protocol stack of each interface a DS_I protocol module is used This module is the same as the DS_I module used in a boundary router Its task is to schedule the transmissions of packets based on their codepoints V Node Editor If a boundary router connects to another boundary router that MAC80211 WPHY 80211P AP ARP DYB S2 FEEDER DVB S2 RCST FWD lt gt belongs to a different DS domain in the protocol stack of the lt lt Mac o211 60211e Macs 0211 MaAc o211 gt gt interface that connects this boundary router to that boundary router a DS_REMARK protocol module is used This module clears the DS codepoints carrie
334. t to each RCST during simulation RCST Bandwidth Allocation After assigning the return link channel capacity to each RCST one has to specify how a RCST uses the allocated channel capacity The following figure shows how a RCST classifies each flow from its outgoing traffic how each flow is delivered into a specific output queue and how the queued data is transmitted out according to a specific capacity request strategy packet scheduling strategy As mentioned before each strategy stands for a specific type of QoS service To set up the flow classification rules one has to first specify how many output queues are used in a given RCST This is done by clicking the Create Queue button and the Delete Queue button on the top left of the tab of RCST Bandwidth Allocation This tab can be popped up by double clicking a RCST node and its dialog box is shown below Application Down time REST Bandwidth Allacation Traffic Queue Traffic Flow Queue lD Queue D sre IF 1 1 101 Z 1 0 3 3 3 1 0 4 4 4 1 0 4 Create Queue Delete Queue lon Prier Maximum CRA capacity is 1996800 bps After creating a queue one can specify what kinds of flows should be delivered into this queue This can be done by clicking the Associate Flow with Queue button and the Disassociate Flow with Queue button on the top right of the tab of RCST Bandwidth All
335. t transmission starts at this time and a blue vertical line indicates that a GPRS packet transmission starts at this time Note that because the ending times of packet transmissions are not depicted here it may be difficult for a user to move the time knot to the time when a packet transmission exactly ends Therefore these vertical lines are depicted here for reference purposes only The GUI program purposely ignores WLAN broadcast packets and does not plot vertical bars for them on the time bar This is because a WLAN access point broadcast its beacon frame every 0 1 seconds and plotting these broadcast packets on the time bar will de focus the user s attention on important packets generated by application programs To know exactly when a packet transmission starts and ends a user can use the printPtr utility program to first convert the binary animation trace file into a text file and then search it in the file lt gt ila Pp Animation playing buttons Animation playing buttons are provided to alter playing sequences They can be executed by left clicking their corre sponding buttons gt plays the animation If a user clicks it while the animation player is idle the player will start to play the packet animation trace If a user clicks it while the animation player is already running the time knot will jump directly to the nearest future time where there is a packet transmission This feature is very useful when the traffi
336. th check marks A user can use this command to display the performance curves of more than one graph source files in the same window It is useful for comparing different performance metrics at the same time PM Menu gt Color Several commands are provided under the color sub menu for setting the colors of the different parts of the graph window w Graphi File Window Color Option Background Axis Grid Graph Use Default Settings TOA a S ell ie time Background Executing this command can select a color from the palette and set it as the background color of the current graph window Axis Executing this command can select a color from the palette and set it as the color of the X and Y axes of the current graph window Grid Executing this command can select a color from the palette and set it as the color of grids of the current graph window Graph This command provides a sub menu from which a user can choose a different graph data source file to display its performance curve In addition the user can select a color from the palette and set it as the color of the performance curve in the current graph window Use Default Settings Executing this command will use the default colors for the background axes and grids of the current graph window PM Menu gt Option alobal setting Graph Mode General Setting Executing this command can set the various presentation parameters of a graph window The f
337. the Magent5 c agent should be run on node 1 during the simulation Right now the CIOD N 1 a E x Aw BOB rrr vw Lak BEBE SHMECP BE R HBP ve Ss aeee sz n pie Te LARRA ij pa m M ir a ai o e F a a DERP 0 00 an on om p AA Mil mb An example network in which a chasing node wants to chase a target node supported tactical agent programs are named Magentl Magent2 Magent3 Magent4 and Magent5 c and Magent5 t Each of these tactical agent programs uses a different tactical strategy and all of them are installed in the default usr local nctuns tools directory NBA o4B 8 eB BSAA E TITTET TET Bete Fee JH LLALLA LSE LLELLE Fee bP ia BER OR ES BAN RAAR HS DERP 1 0 20 Oo on AA i m Simulation Settings for tactical MANET Simulation Before one can start a tactical MANET simulation in NCTUns it is important to enable two options under the Real Time tab which is in Menu gt G_Setting gt Simulation As shown in the following dialog box there are two important options that should be set before a tactical MANET simulation is started The first one is the mode of moving path generation option For a tactical MANET simulation one should set the option as Dynamic moving path generation during simulation to indicate to the simulation engine that a mobile node s moving path will be generated dynamically If the static moving path generation before simulation mode is chosen a mobile node
338. the Network Address Translation NAT function It intercepts incoming outgoing packets properly modifies their IP addresses and port numbers and finally injects them into either the simulated network or the external real life network according to their destination IP addresses The detailed design and implementation infor mation is available in 1 After specifying the emulation topology the nctunsclient program will automatically generate the commands required for setting up the emulation kernel module Then when starting an emulation the NCTUns simulation engine will trigger the Linux kernel to properly load and initialize the emulation kernel module using the specified commands via system calls Because the emulation kernel module consumes some CPU time to perform the required NAT function it is recommended to conduct an emulation using a high speed machine In the following we illustrate the detailed steps to configure an emulation case using the GUI program The Simulation Speed Setting for Emulation Once a user adds an external host into the network topology the speed of the simulation engine will automatically be set to the speed of the real world clock During the simulation the simulation s simulation clock will then be synchronized with the real world clock every 1 ms Therefore the emulation function s latency precision is 1 ms From experimental results it is found that the precision may degrade and vary if
339. the fact that the user may configure it to use the Build in Advance These two modes affect how the switch forwarding table used inside the switch module is built The first method is a dynamic method while the second is a static one The second method works very well for fixed networks However in mobile networks where mobile nodes move around and change their associated access points constantly the static method will no longer work correctly To prevent the user from suffering unexpected wrong simulation behavior and results the GUI program automatically forces the switch module used inside all access points to use the Run_Learning_Bridge method to dynamically build and update their forwarding tables Therefore in the future when you see that the GUI program does not honor your settings for some devices or protocol modules do not be surprised You know that the GUI program is doing this for your good Editing network nodes properties can be done in two steps In the first step a user can use the mouse to double click a node s icon A dialog box will appear in which a user can set parameter values or option values The following figure shows an example dialog box after the user double clicks the router icon Router ID Name Routing Down time Application Mobile IP mintra domain routing table Run time query Run routing daemon show routing table
340. the head car from left to right or from right to left without jumping back and forth Once a car group is formed each of them will try to follow the route taken by its preceeding car during simulation This feature is useful for studying inter vehicle communication among the cars in a car group To manage the created car groups one can perform the Manage ITS cars group tool which is at Menu gt N_Tools gt ITS Network gt Manage ITS cars group This command provides an interface to view the information of a car group and delete a car group which is shown in the following figure TTS Cars Group Management H Cancel Selecting a Group of Nodes To save time and effort a user can select a group of nodes and then apply an operation to all of them The operations that can be applied to a group of nodes include 1 move and 2 delete Using the select tool a user can select a single node by clicking the mouse s left button on the node To select multiple nodes the user can hold the Ctrl key while clicking these nodes Another method is to use the select tool to draw a rectangle area to select all nodes in that area To draw a rectangle area when the select tool is used the user can click the mouse s left button on one point hold the button and then drag it to another point The following figure shows a possible selection result To facilitate selecting a large number of nodes of the same kind s
341. the name e g ethl of the above interface on the simulation machine and the real IP address used by this port on the real world router The dialog box of the external router contains an example to illustrate the settings Fort ID Agap IF addres asagada Simulations Real IF aids used on th armulaua mache f Lil AL N le oi AET re Pe i a OD A LL LA eT a Se The daemon will intercept and process all packets that pass through the network interfaces on the amwatton machine that arm connected to the real router Example Host 1 0 1 1 E temal Router 1 0 1 2 arrlf 1 ethO1o2 Lee 11 Hest TE 2 for Port IG 2 Using the emulation network settings depicted in the following figure as an example assuming that the interface names for the 140 113 1 1 140 113 2 1 and 140 113 3 1 on the simulation machine are eth1 eth2 and eth3 respectively then the association table should contains the following entries 1 1 0 1 2 140 113 1 1 eth1 140 113 1 2 for port 1 2 1 0 2 2 140 113 2 1 eth2 140 113 2 2 for port 2 and 3 1 0 3 2 140 113 3 1 eth3 140 113 3 2 for port 3 Ines i n tame A s e AN I ae ANNAE A h e soe 2 r On ee eS F mes oe eed Ob E A JE R OA b n A e o i ooh M E G e eee eT rae b 4 140 113 1 1 Link 1 140 113 2 1 Link Simulation Machine External Router On the external router in the real world some routing entries need to be added to its routing table
342. the session On the left a media type menu is provided so that a user can easily select one media type without manually entering its associated parameter values To understand the meanings of these media fields the user should reference 5 On the right the user can enter the destination IP address es of RTP packets If multiple IP addresses are entered the RTP program on this host will use multiple unicast sessions to deliver RTP packets to each of these destination nodes RTP Application D a Start Time o sec rtpsendrecw Local IF address End Time sec Application Name Local port number Canonical name CNAME must be unique Browse to select one if it exists E need to input the SOF file name for the RTF application Otherwise the required SDF file can be easily generated here f Edit and save SDP information to a SDF file Select this option if you want RTP traffic to be generated based on a packet trace file input trace file name Browse Each line in the packet trace file represents a packet that should be transmitted and has two columns The first column is the packet size in byte while the second column is the interval time in second between this packet and the next packet Pee ac The RTP dialog box After all information has been entered into the SDP dialog box the user can click the Save
343. the time knot to any desired time This will cause the performance monitor to plot static performance curves over a time interval that starts at the specified time At this stage the whole process of using NCTUns to perform a simulation case is over The user may quit the GUI program at this time while leaving the dispatcher and coordinator program running in the background Post Analyses When the user wants to review the simulation results of a simulation case that has been finished before he she can run up the GUI program again and then open the case s network topology file tpl The user can switch the mode directly to the Play Back mode The GUI program will automatically reload the simulation results including the packet animation trace file and some performance log files Because the animation file size is usually very large the loading process may take a while for a large case After the loading process is finished the user can use the control buttons located at the bottom of the screen to view the animation just like what he she would do when a simulation job is done 1 i Coy Reena ia Sake pir Q Tai 6 Tah G ary h Rag Epa Aero ETICI EEC ECLTEEELETEE E E i ie A os A i D i 5 4 4 fj DERP SHB rr 7H Lia Bebe eel ge amp Bh oa 2 ok Hl E J O00 O00 O00 OO oe oon om QQ lab fl eae Simulation Control Commands During a simulation a user can have c
344. the top left via a fixed link and forms a wireless mesh network together with other mesh SS nodes Using the forwarding capability of the mesh BS node nodes in the mesh network can access the Internet Moreover taking advantage of the routing function of the mesh gateway SS node nodes in the bottom right subnet can access the Internet as well _XAeocoet AE Ob ee Bee aeewas so Pewee ae i we SOMR rr HLL GALA RSH ALSALS See ere BHeSeSBSter BEY AARAA SA OERP q 4 o 5 _is L rd wat i g s s 3 k 0 1 00 n on AG ih Il Setting IEEE 802 16 d Mesh Networks In the following we show how to set up an IEEE 802 16 d mesh network case using the GUI program Insert IEEE 802 16 d Mesh Nodes To deploy an IEEE802 16 d mesh network one can either place mesh network nodes one at a time or place a number of nodes in one step by using the following automatic deployment tool Menu gt N_ Tools gt 802 16 d Network gt 802 16 d Mesh Mode Nodes gt Insert 802 16 d Mesh Mode Nodes CA we ejja yyt wu 4 eee I0 i s fone ThE G amp S LALA FSR E MG ie i AARAA SA DERP 0 oD Oo AQ Ph ilar After executing the Insert 802 16 d Mesh Mode Nodes command the following dialog box will be popped up In this dialog box one can specify 1 the type and the number of the inserted network nodes 2 the positions where the network nodes should be placed and 3 the protocol specific setting applied
345. ther partially it needs to decide how to deal with this situation At present three burst contention resolution methods are provided In the first method the module drops the second burst entirely In the second method the module drops the head of the second burst while in the third method the module drops the tail of the first burst V Node Editor Select Mode AX V Node Editor MAC80211 YW J ar Select Mode a XI Undo Redrawl2 T A H TAN The protocol stack of an optical edge router used in an OBS 113 Parameters Setting Control Packet Processing Time le ns tending Control Packet Resolution Met C Choose the One With the Smallest C Choose the One With the largest Offs Contending Burst Resolution Method Drop the Second Burst Entirely Drop Only the Head of the Second Burst Drop Only the Tail of the First Burst Tail dropping Notification Control Packet Channe Note The tail dropping notification control packet ct not collide with the data and control packet cr the OPT OBWA module which is used inside edge router Of course it should not exceed t number of channels The parameter dialog box of the OPT_OBSW protocol module which is used in the protocol stack of an optical burst switch In the following we show the parameter dialog box of the protocol module OPT_OBWA used inside the protocol stack of an optical edge router in an OBS network This module deals with burst assembly perform
346. ther and imple mented in a single agent program That is a router can act as both a home agent and a foreign agent at the same time V router Router ID Name ROUTERS Routing Down time Application Mobile IP M Enable Mobile IP Enable Route Optimization RO This agent implements both the home agent and the foreign agent Administered MN s IP Address Wireless Interface IP Address Add Delete Add Delete Port Care of address Node editor Ca Cancel Command console For the functionality of the home agent on this router a user needs to enter a list of IP addresses of mobile hosts which view this agent as their home agent This information enables the home agent to know whether an administered mobile host has left its home network or has just returned back to its home network The user also needs to specify a UDP port number for this home agent daemon to use This port number should not be used by other daemon programs used in the simulation case For the functionality of the foreign agent on this router a user must provide the IP address of an interface on this router that connects to a wireless access point This setting tells the foreign agent to provide services on this specified wireless subnet If this router has many interfaces each of which connecting to a different wireless access point and the user wants the foreign agent to provide services on all of
347. these two ports are derived based on the definition explained at the beginning of this chapter For port 2 of the left virtual router it is the IP address of the network interface on the middle emulation machine that connects to this left virtual real router which is 192 168 2 1 For port lof the right virtual router it is the IP address of the network interface on the middle emulation machine that connects to this right virtual real router which is 192 168 3 1 The above configurations must be set correctly as presented Otherwise the distributed emulation will not work correctly After finishing these configurations one can switch the GUI program to the Run Simulation mode and start to perform the distributed emulation Virtual Router External Router ID 5 Use a real router to connect multiple emulation n 92 168 1 254 92 168 2 254 192 168 1 1 192 168 2 1 192 168 1 1 192 168 2 1 Edt Node editor Cancel Use a direct link to connect two emulation machines If two emulation machines are connected via a layer 2 switch they need to be on the same subnet As shown in the following figure the IP addresses of the emulation machines that emulate the left part and the righ part of the network are 192 168 1 1 and 192 168 2 2 respectively The emulation machine that emulates the middle part of the network has two interfaces with the IP addresses 192 168 1 2 192 168 2 1
348. tion Graph Title Eral of oe hv ig i id al 65 66 a 60 28 ae 22 z 0 TO Be OL a aE Noe Cea ea Zier time The performance curve is plotted using the state transition format Summary This chapter presents the functions and relevant settings of the performance monitor A user can use this tool to analyze performance results In addition a user can easily take important snapshots of some performance curves to make reports 7 Emulation he NCTUns network simulator can be easily turned into an emulator An emulator allows real world devices to interact with a simulated network and forces real world packets to experience user specified network conditions Emulation is very useful for testing the functions and performances of real world devices and observe how it would perform under various network condi tions In this chapter we present how to turn NCTUns into an emulator Emulation in NCTUns NCTUns supports emulations 1 In an emulation a real world host an ad hoc mode mobile host an infrastructure mode mobile host or a router can exchange its TCP UDP ICMP packets with any node in a simulated network These real world devices are called external host external ad hoc mode mobile host external infrastructure mode mobile host and external router respectively In addition NCTUns supports a new node type called virtual router which is used for conducting distributed emulations and will be explaine
349. to the dispatcher without first running up it in the GUI and then immediately disconnecting it Its net effect is the same as first running up a simulation job and then immediately disconnecting the GUI program from it A job submitted in this way is called a background job It does not need the GUI s support or occupy the GUI while its simulation is ongoing A background job may wait in the dispatcher s job queue if currently there is no available simulation server to service this job Whenever a simulation server becomes available on behalf of the GUI program that submitted this background job the dispatcher will automatically start the background job s execution on that simulation server Background Job Management As explained before a background job is a job submitted by executing the Submit command After being submitted a background job may 1 wait in the dispatcher s job queue waiting for an available simulation server to service it 2 be currently executed by a simulation server or 3 may have finished its simulation Depending on which state a background job is currently in a user can use appropriate commands to either cancel it reconnect to it or retrieve its simulation results Summary In this chapter we present how to use NCTUns to quickly build a simulation case The package installation process and environment variables setting are covered in detail We also provide a quick tour to help users
350. ts WAVE Multi channel Operation IEEE Vehicular Technology Society October 2006 20 Multi interface Mobile Nodes s the IC technology advances nowadays many consumer electronic devices are equipped with multiple heterogeneous wireless interfaces Such devices have enabled new research topics including hetero geneous network handover and wireless trunking For this research trend NCTUns supports multi interface mobile nodes which are mobile nodes each equipped with multiple heterogeneous wireless interfaces The Multi interface Mobile Node Concept A multi interface mobile node is a mobile node equipped with multiple different wireless interfaces Currently a multi interface mobile node is equipped with eight different kinds of wireless interfaces an 802 11 a infrastructure mode interface an 802 11 a ad hoc mode interface an 802 11 b infrastructure mode interface an 802 11 b ad hoc mode interface an 802 11 p interface a GPRS interface a DVB RCST satellite interface and an 802 16 e interface There are two types of multi interface mobile nodes 1 multi interface mobile node MI and 2 multi interface ITS car Wa As shown in the following figure a multi interface mobile node is allowed to move in any pattern in the field like a WLAN mobile node moving in the random waypoint fashion However a multi interface ITS car is only allowed to move on a road network XA rory On oO OVA Vso Bees I0 rj
351. ts on a subnet in the simulated network it 1s more efficient and convenient to use subnet routing rather than 62 host routing to specify these routing entries The following shows the routing commands for adding these subnet routing entries On FreeBSD route add 200 1 1 24 140 113 1 1 route add 200 2 1 24 140 113 1 1 route add 200 3 1 24 140 113 1 1 route add 200 1 2 24 140 113 2 1 route add 200 2 2 24 140 113 2 1 route add 200 3 2 24 140 113 2 1 route add 200 1 3 24 140 113 3 1 route add 200 2 3 24 140 113 3 1 route add 200 3 3 24 140 113 3 1 On Linux route add net 200 1 1 24 gw 140 113 1 1 route add net 200 2 1 24 gw 140 113 1 1 route add net 200 3 1 24 gw 140 113 1 1 route add net 200 1 2 24 gw 140 113 2 1 route add net 200 2 2 24 gw 140 113 2 1 route add net 200 3 2 24 gw 140 113 2 1 route add net 200 1 3 24 gw 140 113 3 1 route add net 200 2 3 24 gw 140 113 3 1 route add net 200 3 3 24 gw 140 113 3 1 Summary This chapter presents how NCTUns can be turned into an emulator Important concepts about emulation and detailed setup procedures are presented Several emulation examples are also presented to help readers understand how to run an emulation case Reference 1 S Y Wang and Y M Huang NCTUns Tool for Innovative Network Emulations a chapter of the Computer Aided Design and Other Computing Research Developments book ISBN 978 1 60456 860 8 published by Nova Science Publishe
352. ts to another node either a simulated node or an external mobile node it should use the IP address assigned to that node in the simulated network In short the usage of external ad hoc mode mobile host is the same as that for external host External Infrastructure Mode Mobile Host The usage of external infrastructure mode mobile host is every similar to those of external host and external ad hoc mode mobile host The only exception is that in the GUI dialog box of the external infrastructure mode mobile host the user needs to provide the gateway IP address infor mation This requirement is reasonable as in the GUI dialog box of a normal infrastructure mode mobile node in the Interface tab the user also needs to provide such infor mation The following figure shows an emulation example in which one external infrastructure mode mobile host communicates with a simulated host via a simulated wireless access point Like in the external ad hoc mode mobile host case initially the external infrastructure mode mobile host can commu nicate with the host at the top However as time goes by it will eventually leave the coverage area of the wireless access point and no longer can communicate with that host The physical setup and routing configuration for this case is the same as that used for the external ad hoc mode mobile host case Em Ee Boe Ao of ee ing Gre ee jj KA OV EOE HB eMVVAe ves eae ees ia i M l Fr FH LAALSI
353. tworks tactical and active mobile ad hoc networks and wireless networks with directional and steerable antennas It simulates 802 16 d WiMAX networks including the PMP and mesh modes It simulates 802 16 e mobile WiMAX PMP networks It simulates 802 160 transparent mode and non transparent mode relay WiMAX networks It simulates the DVB RCS satellite networks for a GEO satellite located 36 000 Km above the earth It simulates 802 11 p 1609 vehicular networks which is an amendment to the 802 11 2007 standard for highly mobile environment Over this platform one can easily develop and evaluate advanced V2V vehicle to vehicle and V2I vehicle to infrastructure applications in the ITS Intelligent Transportation Systems research field It simulates multi interface mobile nodes equipped with multiple heterogeneous wireless interfaces This type of mobile nodes will become common and play an important role in the real life because they can choose the most cost effective network to connect to the Internet at any time and at any location Support for Various Networking Devices NCTUns simulates common networking devices such as Ethernet hubs switches routers hosts IEEE 802 11 b wireless access points and interfaces IEEE 802 11 a wireless access points and interfaces etc For optical networks it simulates optical circuit switches and optical burst switches WDM optical fibers and WDM protection rings For DiffServ QoS networks
354. ty to attached mobile stations according to their QoS demands during the contention free medium access period A mobile station needs to send a request to the access point to request a certain amount of bandwidth for its streaming data If the request is granted the access point will reserve bandwidth for it and give it enough medium access chances to transmit its data This is done by polling the mobile nodes constantly to allow it to send out its packets In NCTUns the 802 11 e packet scheduler and admission control unit are implemented based on the sample scheduler described in annex K 3 3 of IEEE Std 802 11e 2005 An IEEE 802 11 e Usage Example The IEEE 802 11 e mechanism is used in an infrastructure mode WLAN To simulate an IEEE 802 11 e WLAN network in NCTUns the IEEE 802 11 e access point 4 and the IEEE 802 11 e mobile node 5 should be used Insert 802 11 e Mobile Nodes When placing an 802 11 e mobile node on the working area of the topology editor a user is asked to input the user QoS priority for that mobile node This declares each mobile node s medium access priority during the contention period 118 XA we ee 0 gaja yu wg e sae va i a ROBB rre ww LLaLL aA AASL 74 Bx bhett I E BEY ao Y Ey DERP 3 5 kp l ia 0 mm om om AA Mimp The user QoS priority needs to be set before an 802 11 e mobile node can be placed on the working area of the topology editor If a user want to quickly p
355. ugua D Queue O fre i Dit e k 1 oi LG F i 4 14 a L l 3 a a i Create Queug e utu Aides nen Pood y mum CAA capiciy i bps Gg Bpi RBD Peak Amie lipsi Change Preity Teng a AT Afni Tim VEL Winnie Anta T ter Tolerant Han Ame heference Mode eddo Ce In this area the maximum CRA capacity maximum VBDC capacity and maximum RBDC capacity for each RCST are shown here for the user s reference They cannot be modified here Recall that these maximum capacities were assigned before when the user operated on the tab of Return link capacity which can be popped up by double clicking the NCC node After choosing one queue one can click the Change Priority button to set up this queue s capacity request strategy and the parameters related to that request strategy In the popped up dialog box one has to first choose the trans mission priority Four types of transmission priority are provided RT Real Time VR_RT Variable Rate and Real Time VR_JT Variable Rate and Jitter Tolerant JT Jitter Tolerant Each transmission priority corresponds to a specific request strategy RT corresponds to CRA VR_RT corresponds to CRA RBDC VR_JT corresponds to RBDC and JT corresponds to VBDC If the transmission priority is set to RT one has to set the queue length and the CRA rate The GUI program will disable irrelevant parameters automatically k Service Detail amp 3 Remaining CRA Capacity
356. uld run the WSMP_Forwarding program via its Application tab on the RSU node The following is an example So 146 Finally as shown in the following figure one should run the WSM program on OBUs that want to transmit receive WSM messages The encapsulation and decapsulation of WSMs are realized as program functions in the WSM programs So i So Summary In this chapter we describe how to use NCTUns to build wireless vehicular networks e g 802 11 p networks to conduct ITS researches The detailed operations for road network construction ITS cars insertion and car profile mapping and editing are presented Reference 1 S Y Wang and C C Lin NCTUns 5 0 A Network Simulator for IEEE 802 11 p and 1609 Wireless Vehicular Network Researches the 2nd IEEE International Symposium on Wireless Vehicular Communications WiVeC 2008 2 S Y Wang C L Chou Y H Chiu Y S Tseng M S Hsu Y W Cheng W L Liu and T W Ho NCTUns 4 0 An Integrated Simulation Platform for Vehicular Traffic Communication and Network Researches 1st IEEE Inter national Symposium on Wireless Vehicular Communica tions September 30 October 1 2007 Baltimore MD USA 3 IEEE 802 11p D3 0 IEEE Standards Activities Department July 2007 4 IEEE Std 802 11 2007 Revision of IEEE Std 802 11 1999 June 12 2007 5 IEEE 1609 4 Trial Use Standard for Wireless Accesses in Vehicular Environmen
357. undGraph tfc O Demo16 BackgroundGraph tpl O Demo16 _BackgroundGraph xtpl O configfile conf File name Demo16_BackgroundGraph bmp Open File type Cancel _ fom 6 fie fen GTa uaj i Leas oe tpt xX Ae oa ae Seog ae ye eyeawa pg eae eeg i ae PP CEE l ERENER AT a a e a T Sea eae L BeBERERREtS BEY AR Ra Dee DERP e a ar IEM Fa m A 4 Vn a g w Tp a a TEALA K E of a a 1 x m t u ai 4 i i e 4 a f t a aj H aa A Ce ee Se a Background graph position D w amp ae Top left position xo IF Scaling factor meter pixel OK Cancel 0 11 000000 Scale Background Graph This command can scale the background graph in a different way Sometimes it is more convenient than the scaling function provided in the dialog box of the above Position Background Graph command After executing this command the user will automatically enter the background graph scaling mode In this mode like using the ruler function the user can drag and drop the mouse over a line A dialog box will pop up asking the user how long in meters the line corresponds to in the real world For example on the bottom right corner of the map there is a scale saying that this small segment corresponds to 891 meters in the real world With this information the user can drag and drop the mouse over this segment and input 891 into the dialog box Usually after scali
358. user can start editing the properties of network nodes he she should switch the mode from the Draw Topology to the Edit Property mode In this mode topology changes can no longer be made That is a user cannot add or delete network nodes or links at this time If the user has not given a name to this simulation case the GUI program will pop up a dialog box at this time asking the user to specify one To save the user s configuration time the GUI program automatically finds subnets in a fixed network and generates and assigns IP and MAC addresses to all layer 3 network interfaces In addition the GUI program automatically generates and assigns MAC addresses to layer 2 network interfaces Note that layer 3 interfaces are used by layer 3 devices such as hosts routers and mobile nodes and layer 2 interfaces are used by layer 2 devices such as switches and wireless LAN access points The generated IP addresses use the 1 0 subnetID hostNu mOnThisSubnet format where subnetID and hostNu mOnThisSubnet are automatically assigned The IP and MAC addresses generated and assigned to an interface can be known easily When a user moves the mouse cursor onto a blue box which represents a network interface the IP address assigned to it along with the port ID assigned to it will be shown The following figure shows an example Eve Ea GQ Toots N Tode G Sommo ft ne g Ge Ge mf Aa A Selat brtertace ID 4 Due
359. user double clicks an optical link a dialog box will pop u connect an optical network with a non optical network such i P 8 pop P i l asking the user which channel to specify The following as a fixed Ethernet network An optical edge router is created o i figure shows this dialog box by using the same tool button amp used for creating a normal router in a non optical network This is because once a newly created router is connected to an optical switch the GUI program knows that this router is an optical edge router As such the GUI program installs relevant optical modules into the protocol stack of the interface that connects to the optical Setting itch ee After entering the channel ID a dialog box for this specified Similarly an optical link is created by using the same tool channel will show up shown in the following figure In the button used for creating an Ethernet link between two figure when a user clicks a parameter field s C T A C button non optical devices This is because once a link is created the field s current value will be copied to all channels of the between two optical switches or between an optical switch same optical link On the other hand when a user clicks a and an optical edge router the GUI program knows that this parameter field s C T A L button the field s current value newly created link should be an optical link will be copied to all channels of all optical links in the
360. ve Mode Doney Determini Annee Gen Potta ocd Carecteity Rfaibennateigtit in C4 P T him Suggetied Pow Threshold Value Suggested Power Threshold Value a xX ccording to the table 17 13 in the section 17 3101 of the 80211 2007 specification the minimum carrier sense CS threshold values in dBm of an antenna under the 20 MHz used by the 80211 a network and 10 MHz used by the 8021 p network channel spacing settings are suggested as follows Data Rate Mbps CSThreshold dBm Data Rate Mbps CSThreshold dBm 6 82 3 85 9 4 5 84 12 79 6 82 On the other hand if the Determined by distance option is selected NCTUns will calculate the interference range of a node X for the chosen node based on the desired inter ference range DIR In addition using this mode one can specify the desired transmission range DTR of each node X for the chosen node The connectivity determination mechanism when using this mode is explained here After specifying the DIR and DTR values NCTUns will calculate their corresponding power threshold values using the current antenna and channel model setting The power threshold value corresponding to DIR is called the corresponding carrier sense power threshold CCSPT and that corre sponding to DTR is called the corresponding receive power threshold CRPT The former denotes that under current antenna and channel model setting the minimum value of the antenn
361. w overbook the channel s maximum transmission capacity The following figure shows an example of final assignment results One may see that the final assigned total capacity may differ slightly from the amount that he she specified before This is due to the constraint of the timeslot based capacity alignment In fact the method used by the NCC to grant channel resources to each RCST is timeslot based However in order to let GUI users intuitively deal with channel capacity assignment the GUI program provides a bit rate 131 Retem link anangement Growing RAetum ink capaciy Fuetum ink frequency Foran link arrangement Each Channels masnim raresa Capacity is approRerely j bps Use Free Capacity Aftagnment Limitations on RCST Capacity REST Capsoty Assignment ChanmneySupertrane D ACSO Man CRA bps biar WOO Ibps 11 199900 papap i ora Oe Si ba Cel 1th 450800 a a SRI Mar AOD bps ADOC limec in superframes 460800 i gaith Hora i Ae Fiii Fi 021200 FSR li THS5700 Fi 04S J OHD 36 153500 h h k e e e Node tdia or based interface for users to assign channel capacity If the specified bit rate based capacity is not exactly equal to the bit rate based value converted from a timeslot based capacity the timeslot based capacity alignment will be applied This is done for a user 1 not to overbook each channel s maximum capacity and 2 know the actual channel capacity that the NCC will gran
362. width provided by the TMR BS of the network For this reason one should carefully calculate and determine the uplink sustained rate for each MS in a simulation case 162 Before starting the simulation one should specify the QoS provision setting for each simulated MS node using the Set Qos Provision for Mobile Stations command The path of this command is shown as follows Menu gt N_Setting gt 802 16 j Network gt Transparent Mode gt Set Qos Provision for Mobile Stations The following figure shows the screenshot of this tool When using this tool one is required to enter the Node ID of the specified MS and the desired uplink sustained rate in Kbps for the specified MS w QoS Provision for Mobile Statio E3 QoS Provision Table MS Node ID Uplink Sustained Rate Set Mobile IP For Transparent Mobile Relay Base Stations and Transparent Mobile Station The mobile IP mechanism is used in NCTUns to support the roaming between different TMR BSs It is easy for a user to configure the mobile IP mechanism in NCTUns One can configure the mobile IP setting for a TMR BS via the Mobile IP tab on its dialog box The panel of the Mobile IP tab is shown as follows To enable the mobile IP function one should tick the Enable Mobile IP option on the panel The setting of the mobile IP mechanism has been explained in a previous chapter To save space we do not explain it again here Similar to that of a
363. wise there is exactly one working ring for each direction of the optical link feo fee GO Tees Tees G amp Sate See y BAre B 8 886 veren SHWAL ALSE LD RARKA SS DERP a TEC LLIT HAGEL S ELEJI E DUET SS iLteits GEAR PERE SEER ar RRA The second 2F BLSR protection ring has been configured for the circuit switching optical network feo for GO Joes i lew G Scy Hory Speen Yow pep BAr B 8 SECs Seevevye LAILTE EL SEJ BBtv TTBS SHALSGALSE LB 1791798 SRSBLs SEES BEr aar AQRaN Rae amp DERP z sf on soe ons one A A H D Ii a Di Siem The third 2F BLSR protection ring has been configured for the circuit switching optical network After setting up protection rings the next step is to set up light paths for every pair of optical edge routers in the optical network In a circuit switching network before an optical edge router can forward any traffic through the optical network to another edge router a light path must have been configured and set up between them All traffic that is forwarded from an optical edge router to another optical edge router should travel over this configured light path Usually the lifetime of such light paths are long After a light path is set up it usually lasts for a few hours or a few days before being tore down due to link switch failures or for load balancing purposes In NCTUns two methods are provided for setting up a light path In the first method a user can use t
364. work Service Access Point Identifier and QoS level can be routed and directed to different GGSNs for receiving different QoS treatments The following figure shows a GPRS network with three GGSNs aos atte fy Getter Suet i ho asenvuivuug S226 ae SC EF LEALL SILA Tae p Bebb EHS st me Ae ae Boe DER F lt i N L nn Ta A AERE EG z To pay the mapping between NSAPI QoS level and the outgoing GGSN the Menu gt N_ Tools gt GPRS Network gt GPRS GGSN gt Edit GPRS Service Table command can be executed The following figure shows its dialog box Note that this mapping table is only meaningful for phone traffic going out from the GPRS network For traffic that is originated from the fixed network and destined to one phone in the GPRS network the user cannot control which GGSN will be chosen as the entry point into the GPRS network Instead the routing entries that determine which GGSN will be used are automatically generated by the GUI program EAn E PIETET TELT Lig meee gt ae ALEJ WILLALL SUL SALSA Lease Be Bebe ewes e he e HARRA aD ERP fj fg li m mi m m E Se ep Ea EIM p nA ER pal b il a 2 E i iki J Paci AD 98 Setting Phone and BS Phone Before using a GPRS phone a user must first attach it to the GPRS network This operation allows the GPRS network to know the existence of the phone In addition before sending traffic from a phone via a SGSN and a GGSN to a host in the fixe
365. y editor This function will be presented later in this chapter With a background map when the simulation is executing or when the playback is going on the user will see vehicles move on highways or roads on the map and vehicles wirelessly exchange their packets via other vehicles This will give the user a global view of wireless transmission activities on a highway or in a city Generate Random Waypoints The Menu gt G_Tools gt Generate Random Waypoints for Mobile Nodes command can be executed to generate random waypoints for all WLAN mobile nodes There are two ways of doing this job The first one is to generate the next waypoint randomly for all mobile nodes When the user clicks the button one more random waypoint will be generated for every mobile node The user can press the button continuously to continuously generate more random waypoints The other way is to automatically generate random waypoints until the arrival time of the last waypoint exceeds the specified time The following figure shows the dialog box of this function h random waypoint Default moving speer 10 Generate the next point Create a sequence of points until Remove All Moving Paths Executing this function will delete all mobile nodes moving paths This will give the user a clean working area to start with This function is located in Menu gt G_Tools gt Remove All Moving Paths of Mobile Nodes Import Network Traffi
366. y generated here Otherwise the required SDF file can be easily generated here Edit and save SOF information to a SDP file Edit and save SDF information to a SDP file Select this option if you want RTF traffic to be generated c Select this option if you want RTP traffic to be generated based on a packet trace file based on a packet trace file Input trace file name Input trace file name Browse Browse Each line in the packet trace file represents a packet that Each line in the packet trace file represents a packet that should be transmitted and has two columns The first column should be transmitted and has two columns The first column is the packet size in byte while the second column is the is the packet size in byte while the second column is the interval time in second between this packet and the next interval time tin second between this packet and the next packet packet Cancel OK Cancel OK Hostl s RTP dialog box Host2 s RTP dialog box SDP Information SDP Information ORN 6 Email address 056014 gmail com should be sent every RTCP packets Email address should be sent every is RTCP packets Phone number should be sent every RTCP packets Phone number 035712121 54706 should be sent every RTCP packets Session bandwidth i600 kbps Session bandwidth 1600 g kbps Session active time from Jo secto fo sec Session active time from 05 secto 200 sec fo PCMU
367. y on the GUI machine For example the tdump log generated by the previous tcpdump i eth3 w tdump log dst port 8002 command will be transferred and stored in the case s XXX results directory In addition to the above shared tabs each device may have its own ones We present them below 2I Host ID 1 Name HOST l Application Down time Mobile IP Add Start time Stop time s Command input file name Modify Add RTP Modify RTP Delete App Usage The Mobile IP tab is related to the Mobile IP protocol NCTUns supports the Mobile IP protocol including both the basic scheme and the advanced route optimization RO scheme The types of nodes involved in Mobile IP are host correspondent host mobile node infrastructure mode and routers where the home agent or the foreign agent is running As such all of these types of nodes have the Mobile IP tab More details about how to run Mobile IP will be discussed in a later chapter The Add RTP and Modify RTP buttons are for RTP RTCP and SDP protocols A user can use Add RTP to specify the various parameters given to a RTP application program Like the Modify button the Modify RTP button is used to modify a command string generated by a previous Add RTP operation T
368. ypes of wireless mobile interfaces that can be added into a multi interface car Select the interfaces that this ITS car is to be equipped with interface list 802 1l a infrastructure mode interface a ad hoc mode interface _ 802 11 b infrastructure mode interface _ 802 11 b ad hoc mode interface 802 11 p OBI GPRS radio DVB RCST Return Channel Satellite Termina 802 1 amp e mobile station 149 An alternative is to use the automatic deployment tool to add a number of multi interface ITS cars at a time The location of the automatic deployment tool for multi interface ITS cars is Menu gt N_Tools gt ITS Network gt Deploy cars automatically and select the session of ITS car with all different interface The following figure shows the dialog box of this deployment tool V Traffi Proper ty ITS car interface type ITS car with an 80211 b infrastructure mode interface ITS car with an 80211 b ad hoc mode interface ITS car with an 80211ip interface agent control led ITS car with an 80211 p interface module control led with a GPRS radio with a DVB RCST Return Channel Satellite Terminal car with an 80216e interface with all different interfaces Average distance between two cars on the same lane The maximum number of total deployed cars on the roads After setting up the Average distance between two cars on the same lines and The maximum numb

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