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SXC T - Theseus

1. 32 6 7 Documentation and pDKeep nanus au u nn an 32 66 DIES LEOTE Ee eror poi bte C plv ite MAE 34 S 36 ee me aD uh meist 38 YANI OLATA KE y Bi ied ce E 39 Appendix 1 SXC_BSC xls circuit chart Appendix 2 NSN SXC T Quick Reference Guid Appendix 3 NSN SXC T Briefing PowerPoint 1 Introduction The demand for mobile communication systems has exponentially increased during past decades The need for people to communicate and the growing activity of international business has created an ever emerging market for personal mobile solutions GSM is the most popular mobile phone standard in the world today It is used by over three billion people and it is estimated to dominate around 80 of the global mobile market GSM As sociation 2009 Nokia Siemens Networks NSN is one of the world s leading telecommunications solu tions providers today Working on this thesis begun when student was recruited as summer trainee at local NSN company site located in Tampere Finland Regional office of Tampere centralizes mainly on research and development The department that recruited student per forms testing of the hardware and software of a specific GSM network element called Base Station Controller BSC Functions of this unit will be explained later Initially student was given a task to impr
2. ET2E 0 Control PCM function ETTOO Control PCM bandwidth 4 Control PCM number 12 Control PCM timeslot 17 PCM function ETTOO PCM bandwidth 4 PCM number 98 PCM timeslot 0 Ej FJ Er Er EJ EJ FJ FJ Ez Verification ZWTI P ET 98 WTI P ET 98 EXECUTION STARTED READING DATA FROM DATABASE ET 98 IN LOC 1 153 01 ET2E TRACK 17 MS ME IS IZ INT 5W 06490003 TSLS 30 20 10 0 ETTOO 41 PCM 12 00000000000000100000000000000000 R 00000000000000000000000000000000 ETTOO 4M PCM 28 B 00000000000000000000000000000001 R 00000000000000000000000000000000 TOTAL OF 1 UNITS 1 PLUG IN UNITS AND 2 FUNCTIONS COMMAND EXECUTED Step 2 Connecting ET s to lineup After creation of ET s they must be connected to the lineup using command ZWUC ET index type and signalling type must be defined here ET type is typically ET2E ZWUC ET 98 ET2E 0 UPART DCS TSU 1 6 18 Upart defines the user part of an ET Signalling type is configured here DSC Digital Cross Connect system ET TSU is the supervising computer unit There are two Trunk Supervision Units configured in SXC T TSU 1 currently controls Verification ZWTI P ET 98 WTI P ET 98 EXECUTION STARTED READING DATA FROM DATABASE ET 98 IN LOC 1 153 01 2 0 TRACK 17 MS ME IS IE INT
3. 53 0 153 01 ET 64 H H125 01 ET 128 125 01 128 H ETS 448 125 37 ET 192 125 37 ET 192 H 449 091 37 ET 256 H HET 66 29 01 ET 320 029 01 320 HET 67 HET 69 00 453 153 37 ET 448 53 3 HET 70 ETS 454 125 01 ETSL 25 01 512 71 455 125 372 ET 576 125 37 ET s76 HETS 72 01 ET 768 063 01 ET 768 HET 75 ETS 453 063 37 ET 896 053 37 9 6 76 4 amp 0 29 37 960 029 372 ET 960 HET 77 461 H HETS 78 462 H LET 81 HETI 82 85 ET 79 463 H 80 83 467 H 84 468 465 CCH 469 H Figure 20 Example of graphical view of ET statuses and connected circuits ET s are indentified by index numbers Despite of its defects SXC T manager was well fitted for daily administrative tasks like creation and deletion circuits Therefore student decided to teach test engineers in both op erating the device via MML and manager program This way everyone could adopt the way they personally find most suitable User training is discussed later 31 39 6 6 Nethawk monitor connections Finally when all lines were physically connected and circuits created between them it was time to set up monitoring connec
4. Open Log File Close Log File Print Print Setup x Exit Step 4 Manager views Status of the node can be examined through various views that are available in the Manager You can adjust the layout under Views and Windows tabs Manage Edit Configure Alarms Views Options Testing MMLCommandFile Window Help CONNECTION VIEW 153 01 64 1E Cross connections View 5 ni x cot 116 Creation Date amp Time State Connection Name t 153 01 153 01 loj x munti 2 2 Configuring ETs Step 1 Managing ET functional types 15 18 To change the functional type of an ET from the ET Status View select the appropriate ET which should be in SE NH state and choose Configure gt ET Functional Type or right mouse click gt ET Functional Type SXC Manager ET Status View 77 Manage Edit Configure Alarms Views Options Testing MMLCommandFile Window Help ET Staus Change ET Functional wo wo ET No ET Functional Types C TRSP Cancel DATA Help TRSP z Transparent switching full 2 Mbit s DATA Timeslot based switching CAS Timeslot based switching with timeslot 16 assigned to Channel Assiociated Signalling CAS Step 2 ET states You can change the state of an ET from the ET Status View Select the appropriate ET and choose Configure gt
5. YEI ET 98 SXC DX220 LAB 2009 08 18 10 37 18 PCM DEFINED FUNCTIONAL MODES PAGE 1 UNIT FUNCTIONAL FRAME ALIGNMENT SA BITS FOR MODE MODE Q 1 USE ET 98 TRSP COMMAND EXECUTED 1 2 Circuit groups 8 18 In order to use Exchange Terminal for circuit switching the participating ET PCM s need to be ina circuit group Circuits are created with command ZRCG Create Special Circuit Group Step 1 Creating circuit group ZRCG SWI TYPE S CGR 2 NCGR ABIS02 CRCT 98 0 amp amp 32 TYPE Circuit group type S Semipermanent circuit CGR Group number NCGR Group name CRCT PCM and timeslots assigned to group Step 2 Assigning circuits to circuit group ZRCA SWI NCGR ABIS02 CRCT 99 0 amp amp 31 NCGR Circuit group name CRCT PCM and timeslots assigned to group Verification ZRCI SWI NCGR ABISO2 RCI SWI NCGR ABISOZ SXC DX220 LAB 2009 08 18 10 41 24 CIRCUIT GROUP 5 CGR NCGR TYPE CGR USE DIR TREE NBCRCT STATE STD 2 ABISOZ INT S 64 CRCT CIC ORD CTRL HUNT STATE DCS 28 0 1 E 98 1 2 22 28 2 3 22 WO EX 98 3 4 WO EX 98 4 5 WO EX 98 5 6 WO EX as amp 7 WA F lt 1 3 Cross connections Step 1 a Creating Cross connections PCM based cross connections are created under the menu item Routing options gt semipermanebroadband Connections handling ZRB ZRBA PCM 98 PCM 99 BW 32 B
6. 50 06490003 TSLS 30 20 10 0 ETTOO 41 PCM 12 B 00000000000000100000000000000000 R 00000000000000100000000000000000 ETTOO 41 PCM 98 000000000000000000000000000000 1 R 000000000000000000000000000000 TOTAL OF 1 UNITS 1 PLUG IN UNITS AND 2 FUNCTIONS COMMAND EXECUTED Step 3 Managing ET functional types ZWHM ET 98 TRSP TRSP Transparent switching full 2 Mbit s DATA Timeslot based switching CAS Timeslot based switching with timeslot 16 assigned to Channel Assiociated Signalling CAS The ET should be in SE NH state before you are able to change its functional type Verification ZWHI ET 98 WHI ET 98 EXECUTION STARTED SXC DX220 LA B 2009 08 18 10 30 49 FUNCTIONAL TYPE OF UNIT S UNIT FUNCTION 98 TRSP COMMAND EXECUTED Step 4 Managing ET states 205 98 5 205 98 ZUSC ET 98 WO Verification ZUSI ET 98 USI ET 98 EXECUTION STARTED SZC DX220 LA B WORKING STATE OF UNITS COMMAND EXECUTED 2009 08 18 10 34 07 UNIT MB STATE LOCATION 98 WO EX 1 153 01 TOTAL OF 1 UNITS INFO TSU 0 iz Step 5 Managing ET functional modes ZYEC ET 98 TRSP NORM if type is DATA CAS TRSP if type is TRSP 7 18 SATR amp V11M Special purpose when Sa bits are switched separately B5678 amp B56 are for these modes only CRCA if CRCA is used DBLF if CRC4 is not used Verification ZYEI ET 98
7. ET Status Change or right mouse click gt ET Status Change SXC T Manager ET Status View 2 Manage Edit Configure Alarms Views Options Testing MMLCommandFile Window Help J SA ET 21 6 Status Change Cancel SE DU C SE NH Step 3 ET functional modes ET functional modes can be changed from the Connection View Click Configure gt Functional Modes or right mouseclick ontop of the appropriate ET and select Functional Modes 16 18 m 516 1 m 1 2 Add Transparent Gross connection Delete Transparent Crass connection dd Trunkdine Protection Delete Protection Delete Test Connection Connection Details Functional Modes xi ET OK Functional Mad mum m 1 Non Transparent Non Transparent f NORM SATR C V1IM Frame Alignment Bit Patten DBLF 886 CRC4 88678 NORM if type is DATA CAS TRSP if type is TRSP SATR amp V11M Special purpose when Sa bits are switched separately B5678 amp B56 are for these modes only CRC4 if CRC4 is used DBLF if CRC4 is not used 2 3 Cross connections You can add point to point point to multipoint and transparent connections in SXC Manager You can add connections by entering the Cross connections View In this view the shortcut keys to add connections in the top toolbar become act
8. FFFF 5725 ACCUSED PLUG IN UNITS INDEX LOCATION TRACK SWCSM 16 16019 01 6 END OF REPORT Figure 19 TSU 1 diagnostics pinpoints the physical location and index of the faulty plug in unit Troubleshooting mentioned problems required time and effort as student ruled out the pos sible causes of malfunction with the help of other test engineers Finally it was discovered that a faulty plug in unit was causing the SCU to fail and when comparing the cabling chart with device cabling we found out that OMU plug in unit had one cable connected incor rectly After system was stable a backup was taken At this point backups were named ac cording to date and there was a simple separate documentation about prevailing system state in each backup 6 4 Building up new environment Next it was time to start building physical and logical connections Initially student was given one BSC and two BTS s to test things out before full scale implementation This way it was easy to spot possible errors and fault situations in different scenarios without affect ing the ongoing testing With help from staff responsible of laboratory equipment student connected these tree network elements to SXC T using PCM cable two cables from BSC and one from each BTS SXC T ET s were powered up and a transparent bidirectional connection was established between links With help from test engineers student also per 30 39 formed BTS and BSC configu
9. Interface 64k 2M nterface TDM um Switching Unit ins Signalling Switch a Operation and Maintenance Module Switch Interface Control Supervision Unit Uni Message bus Operation amp Maintenance optional unit Q3 Management input output Figure 7 Block diagram of the SXC T displaying computer units in each module Units drawn using dash line are optional and not used in NSN laboratory Source Nokia Networks 2000a 21 4 2 1 TDM switching module The TDM Switching Unit performs switching of internal incoming outgoing and transit traffic It also handles the internal control connections of the SXC T Line Signaling Switch is an optional computer unit that is used in special timeslot based switching This is not used in NSN laboratory 18 39 4 2 2 Interface module Interface module of SXC T consists of 2 Mb s Interface Units ET64 A single ET64 be equipped with up to 32 ET2E plug in units An ET2E is a physical card that contains two 2 Mb s interfaces Figure 8 displays the principle of the module build up Interface Module Consists of 2 Mb s Interface Units ET64 Consists of two ET 2 Mb s interfaces Consists of 32 ET2E plug in units ET64 unit ET2E plug in unit 2 Mb s Figure 8 Module gt Unit gt Plug in unit This hierarchy applies to all DX200 architectures A digital circuit is
10. John Wiley amp Sons Ltd Nokia Networks 2000a SXC T Service Cross Connect for Time division multiplexing Product Description Nokia Networks Oy Nokia Networks 2000b SYSTRA GSM System Training Nokia Networks Oy 39 39 Appendices Appendix 1 SKC BSC xls circuit chart Appendix 2 NSN SXC T Quick Reference Guide Appendix 3 NSN SXC T Briefing PowerPoint slides BSC ET SKC SKC TCSM MSC BTS SGSN Media Gateway TCSM2i 11 Metro 123 Ultra 60 Metro 55 TCSM3i Talk 14 Metro 44 TCSM3i Liisa 551 TCSM3i Cabinetmaster Flexi 102 Flexi 102 Flexi 102 Flexi 102 Flexi 102 Flexi 102 Flexi 102 Flexi 102 Ultra 83 0 N O1 OO N Flexi 206 Flexi 206 Flexi 207 TCSM2i Ultra 95 Ultra 95 Ultra 95 Ultra 82 Ultra 82 Ultra 82 Ultra 120 Gemini Ultra 121 Ultra 121 TCSM3i TCSM2i Flexi 103 Ultra 80 Flexi 207 Flexi 207 452 TCSM2i 102 gt 510 511 gt 563 Ultra 84 103 Kummola 256 Maija 256 178 459 TCSM2i 12 Liisa 553 Maija 257 179 289 Leevi 33 Maij Mai Mai Maij oH Tellervo Tellervo Tellervo Tellervo Tellervo Tellervo Tellervo 581 584 578 579 TCSMSi TCSMSi Ultra 99 Flexi 109 Metro 27 Metro 69 Ultra 81 Ultra 126 Ultra 126 Ultra 2000 Ultra 117 Ultra 77 Ultra 111 Flexi 104 Netta 784 787 1 18 Appendix 2 NSN SXC T Quick Reference Guid
11. pdf Quick reference guide amp slides by trainee pdf Cross connections xls Backup documentation m Dew ia Sieme Works ft k For internal use ly 22 Nokia Siemens Networks
12. version with correct software build It was decided that old configuration should be erased in order to correspond a clean install This included erasing and recreating all circuit groups All ET interfaces in SXC T belong to a circuit group Circuit group type number name and participating ET s can be modi fied Student decided to assign the interfaces that connect to similar network elements in same groups This required utilization of the ET allocation plan that was created earlier ET types modes and states were reverted to transparent mode A transparent network element does not modify traffic that passes through it but only forwards it accordingly It is invisible to other devices in the network It s the most simple and efficient way to operate SXC T AII of the 32 timeslots in single PCM line in outgoing interface are transmitted ex actly the same way as they were received in the incoming interface This enables switching of whole PCM lines 32 timeslots instead of individual timeslots which is required only under special circumstances All ET s were initially offline and were powered on along the way because an ET2E unit that is up and running but has no connection causes Signal Missing alarms to alarm log In this step we also set clock synchronization which is a vital feature for all telecommuni cation network elements We decided to wire an independent signal cable from atomic clock into the clock synchronization interf
13. Computer units can be forced to undergo diagnostics in attempt to locate origins of the fault Below is an example of deliberate error creation and troubleshooting on TSU 1 Trunk Supervision Unit index 1 This was caused by pulling out a plug in unit and reset ting the computer unit Figures 17 18 and 19 display the alarms and unit states caused by this error situation SXC DX220 LAB 2009 10 02 10 26 57 ALARM HISTORY lt HIST gt DX220 LA B TSU 1 O M 2009 10 02 10 19 56 51 DISTURNTSU 1 1 001 37 USAPRO RECOV 1894 NO RESPONSE TO SUPERVISION MESSAGE lt HIST gt DZ220 L B OM SWITCH 2009 10 02 10 19 56 64 NOTICE TSU 1 1E001 37 RCXPRO 0691 AUTOMATIC RECOVERY ACTION SP EX TE EX 4 02 0002 7889 1894 0000 0000 HIST 0 220 OMU SWITCH 2009 10 02 10 19 57 25 ALARI TSU 1 1EQ01 37 RCXPRO 2383 2692 INCORRECT WORKING STATE Figure 17 First symptoms of a failure are the notifications in system alarm log 29 39 SXC DX220 LAB 2009 10 02 10 24 02 WORKING STATE OF UNITS UNIT MB STATE LOCATION INFO OMU DO WO EX SCU 0 04 WO EX SCU 1 05 SP EX P FAULTY UNIT REVIVING BY SYSTEM INCORRECT STATES COMMAND EXECUTED Figure 18 Unit state can be verified from working state interrogation SXC DX220 LAB 2009 09 07 13 01 06 DIAGNOSTIC REPORT TSU 1 1C001 37 550 1 16061 01 PARTIAL DIAGNOSIS GSU DIAGNOSTIC PROGRAM 0042 DIAGNOSIS 0011 EXTRA INFO 1 0010 EXTRA INFO 2 0000
14. SXC T At and planned ET allocation ETC ET64 unit 48 60V 32 ET2E cards ETC 11 ETC 12 TSU 0 Since the system will be a critical part of the network it is important to take regular system backups During configuration backups were taken after each phase to be able to take a step back in case something irreversible happens A regular backup policy was to be planned after system configuration is completed Backups are automatically stored and rep licated to both hard disks located in Operation amp Maintenance computer unit Student was also given a task to familiarize with a graphical user interface for SXC T Stand alone PC software called SXC T Manager is a program designed particularly for SXC T management Initial configuration was to be performed using MML because graph ical user interface may lack features Also in order to understand the system it was impor 24 39 25 39 tant to learn principles of command line configuration Manager may be used later on to perform configuration routines 6 Execution phases 6 1 Enabling IP connectivity Enabling IP connectivity in order to support easy remote node management was the first task Using Ethernet cable SXC T was connected to distribution layer IP switch responsible for connecting all laboratory equipment with the company LAN Vlan and port descriptions were configured to Cisco Catalyst 2950 switch port COCEN plug in unit in SXC T was configured
15. connected to the TDM Switching Unit via an Exchange Terminal ET Exchange terminal performs synchronization of signals and converts and decodes received line code into binary form for switching unit in the incoming interface Exchange Terminal in the outgoing interface converts the binary code back to proper line code for transfer across physical medium Nokia Networks 2000a 24 4 2 3 Operation and Maintenance module The Operation and Maintenance module consists of multiple units computer units which have differing tasks The units are Operation and Maintenance unit OMU clock system CLS Clock and Alarm Buffer CLAB Switch Control Unit SCU and Interface Super vision Unit TSU The Operation and Maintenance unit allows the remote and local management of the SXC T It s the main source for loading software It also stores performance and accounting sta tistics collects hardware alarms and controls switchovers Switchover is a function where duplicated computer unit also called a spare unit can take over the tasks of operating com puter unit in case of hardware failure Operation and Maintenance Unit is also used as the interface unit for any peripheral devices Nokia Networks 200a 4 8 For fault tolerant data management purposes the Operation and Maintenance Unit is always accompanied by a duplicated hard drive for backup and data management purposes and duplicated power supply Nokia Networks 2000a 27 In Nokia Siemens Net
16. devices such as printers terminals or standard PCs may be physically connected to the OMU The default solution is to use asynchronous serial interface V 24 V 28 Nokia Networks 2000a 33 Centralized network management allows flexible remote control over node It can be achieved via a 64 Kbit s timeslot X 25 connections from a public data network or a CO CEN plug in unit for TCP IP connectivity Nokia Networks 2000a 33 In NSN labora tory TCP IP connectivity is enabled by connecting COCEN plug in unit in OMU to the company LAN IP switch The management tasks include traffic fault and alarm monitoring and administration hardware and software configuration administration and routing and circuit switching ad ministration 20 39 5 Planning of SXC T implementation The purpose of the laboratory in Tampere is to provide means and equipment for testing using live network equipment Different verification steps and procedures must be carried out before a new software version or technical implementation can hit the global market and live network deployment Different testing phases require different environments load testing is performed with thousands of virtual mobile stations hosted by a dozen physical computers Unit testing makes sure that the internal and external messages that the devices use to communicate are correct in a very detail level In feature testing the idea is to test the full system functionality using Mobile Stat
17. is a combination of terminal equipment or in other words Mobile Equipment ME and SIM Subscriber Identity Module SIM holds data needed for the subscriber to use the network Basic GSM network architecture is presented in Figure 4 11 39 Network Management amp Subsystem SS Workstation Database Server Database Server MSC VLR AuC EIR Base Station Subsystem Network Switching Subsystem Figure 4 Standard GSM network architecture and its interfaces 3 2 1 Network Switching Subsystem NSS Network Switching Subsystem consists of Mobile Switching Centre MSC and the follow ing registers of which some are optional Home Location Register HLR Visitor Location Register VLR Equipment Identity Register EIR Authentication Centre AuC and Group Call Register GCR The subsystem is responsible for call control charging and mobility management in GSM network Mobility management is one of they key features in GSM which aims to monitoring the location of subscribers so that mobile phone ser vices can be delivered between users regardless of their location Below is a short descrip tion of each of the registers and its function Visitor Location Register e Stores information about subscribers in its service area Temporary database when a user moves to the service area of a different VLR the information from previous VLR is erased Home Location Register e Stores subscribers data and location p
18. of executions 33 39 IDL WDU O DATAFB COMMANDS OF FILE WDATAFB CMD INDEX CMD PARAMETERS 1 ZWKS MODE DATA COMMAND EXECUTED Figure 23 The command ZWKS is used to create an incremental backup of data files type DATA A command file called DATAFB CMD was created ICI DATAFB 0 IDENTIFY COMMAND FILE TYPE INTERRUPT EXECUTION IN ERROR CASE UNINT CONTINUE EXECUTION IM ERROR CASE DEFAULT IS CONTINUE ERROR CASE TCI DATAFB 0 INT CALENDAR TASK EXECUTION PARAMETERS PARAMETER NAMES DATE DATE OF EXECUTION TIME TIME OF EXECUTION PTYPE EXECUTION PERIOD TYPE PNBR NUMBER OF EXECUTION PERIODS DAYS EXECUTION WEEKDAYS ALARM EXECUTION ALARM NUMBER AUNIT ALARMING UNIT DSTUM DESTINATION UNIT OF ALARM ASTATE ALARM STATE NBR NUMBER OF EXECUTIONS SAVE SAVE COMMAND AFTER EXECUTION Figure 24 Command calendar execution parameters 6 8 User training Though device manuals were already supplied with SXC T there was a demand among test engineers for a simple quick user guide that would include all the basic SXC T commands These were deletion and creation of circuits and circuit groups monitor connections han dling of ET modes states and settings Student decided to introduce the usage of both MML and graphical Manager program On some occasions however using SXC T Man ager was not feasible because of th
19. with IP address subnet mask default gateway network frame type length and allowed protocols telnet ftp Few verification command outputs are displayed in figures 13 and 14 QRI EXECUTION STARTED SXC DX220 LAB 2009 08 18 10 57 28 INTERROGATED NETWORK INTERFACE STATIC INTERFACES IP ADDRESS UNIT STATE TYPE MTU NETMASK LENGTH PIU FRM ROU OMU UP ETH 1500 10 8 189 175 24 7 DIX 1 COMMAND EXECUTED Figure 13 A COCEN plug in unit settings in operation amp maintenance OMU computer unit 1 EXECUTION STARTED SXC DX220 LAB 2009 08 18 10 59 43 INTERROGATING ROUTE DATA NBR UNIT DESTINATION NET IF NEXT HOP PRI STATE OMU DEFAULT ROUTE 10 8 189 1 100 COMMAND EXECUTED Figure 14 Default gateway next hop IP address and link state 26 39 6 2 Replacing old hardware Since the device was delivered from another NSN site it had been used in another network earlier Hardware and software configurations were left untouched Student needed to re move and uninstall hardware that was of no use in our laboratory so it would be possible to replace it with new parts Before committing any changes old system configuration was saved and documented for future guideline Computer units were left in place but most of the Exchange Terminal ET cards had to be changed Old environment was using coaxial cable connectors while we were using Euro type connectors in our PCM cable ends ET cards of
20. wrong type and circuits that were connected to them were removed New ET cards were mainly acquired from the old unused BSCs We also had to check that strapping pins on new cards would match those on the old ones Pins control for example frame and signal processing Below is a photo of an ET2E card Strapping pins and Euro type connector are marked to the picture Figure 15 Euro type connector ET card ET2E After physically mounting the cards they had to be manually created in software and con nected with the line up using MML interface There is no plug and play feature For ex ample card s physical location index track type mode supervising unit supervising PCM and timeslot numbers had to be allocated manually Device manuals and the preceding con figuration acted as instructions for configuring the new hardware First backup fallback copy from system state was taken after all old ET cards were replaced with new ones 27 39 6 3 Reworking basic software configuration After new hardware was in place and installed the rest of the old configuration was to be erased Idea was to start from clean environment so that we could rule out the possibility of old configuration errors affecting the newly created set up Original plan was to find and install new blank operating system for SXC T after the ET cards were replaced Despite of searching manufacturer databases and company network storages we failed to recover a
21. 2 5G in order to dis tinguish the difference between the original basic 2G GSM functionality Penttinen 2006 14 One of the many reasons why GSM became the prevalent 2G mobile technology was that during the specification it was foreseen that national telecommunication monopolies would be disbanded and several competing network operators should exist in each country The specification determined that GSM was to be an open system meaning it would contain well defined interfaces between different parts of the system Tisal 2001 12 13 This en 9 39 ables the equipment from several manufacturers to coexist and hence improve the cost efficiency and users would find the cost of calls reducing GSM continued its success and is still under constant development by many network ven dors including Nokia Siemens Networks It evolved from pan European standard to world wide utilization Although new generation products like 3G UMTS Universal Mobile Telecommunication System and 4G LTE Long Term Evolution are being developed and implemented GSM is still the most widely used standard for mobile telecommunication New technologies are not designed to replace but co operate with legacy systems For ex ample as an end user it can be hard to tell whether your mobile is using 2G or 3G Below is a map of the GSM and UMTS coverage in the world in January 2009 Figure 2 Legend csm coverage 3GSM Coverage Figure 2 GSM an
22. CU Switch Control Unit E ee GSW Switching Unit LSW Line Signalling Switch CLS Clock Synchronization Unit 9 ETC 10 CLA Clock and Alarm Buffer TN ET Cartridges EE 2 3 ETC 11 nokia Netw S N is internal use only Nokia Siemens Networks 3 ET Configuration nitial setup 1 Create plug in 2 Connect plug in Add PCM to circuit group 4 Change ET functional type 5 SE NH WO EX 6 Change ET functional mode Functional modes CAS DATA TRSP Functional types NORM DBLF CRC4 TRSP SATR 11 Nokia Siemens 3 Network N e 5 S or internal use on N Networks 3 ET Configuration For internal use only 7 Nokia Siemens Networks NON TRANSPARENT MODE DBLF CRC4 TRANSPARENT MODE Key NORM Normal mode SATR Transparent switching of S bits requires optional ET2DV units V11M V 11 mode requires optional ET2DV units TRSP Transparent mode DBLF Double frame mode CRC4 CRC4 mode 856 5 bits 5 and 6 in use 85678 S bits 5 6 7 and 8 in Q1 use Nokia Siemens Networks 4 Circuit groups AI PCM circuits must be assigned to a circuit group Circuit groups are created only once RCI SWI For internal use only 8 Nokia Siemens Networks SXC CIRCUIT GROUP 5 C
23. GR DX220 LAB NCGR ESC1 BSCZ BSC3 BSC4 5 5 SGSNO SGSN1 SGSN2 SGSN3 SGSN4 MSC1 MSC2 BTS1 BTS2 BTS3 BTS4 NETHAWK1 NETHAWK2 LSSW TG ETTOO DAS7U CLS TYPE CGR USE DIR TREE NBCRCT STATE INT S 5 5 5 5 5 5 INT S INT S INT S INT S INT S INT S INT S INT S INT S INT S INT S INT S INT S 5 5 5 XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX 2009 10 20 1024 1024 1024 1024 1024 1024 1024 1024 1024 1024 1024 1024 1024 1024 1024 1024 1024 1024 1024 3 320 704 2 Nokia siemens N etworks 5 Cross Connections Switching Cross connection types Transparent Point to point Point to multipoint ZRB Figure 11 A point to multipoint connection Switching Switching ET Matrix Matrix ET Figure 10 Multiple point to point connections Figure 12 A transparent point to point connection Siemens 3 Networks N internal use only ST SIIN O Nokia Siemens Networks 5 Cross Connections MML Menu ZRB Semipermanent broadband connections handling ZRBA multichannel connections ZRBB point to multipoint connections RBA PCM 85 PCM Z D BW 3Z BI TESTI1 TESTIZ FBL1 CECT 55 0 cFCT 200 0 EW 4 BI TESTI3S 14 _ RBI E
24. I PCM based circuit handling 98 PCM in 99 PCM out BW Bandwidth number of timeslots BI Bidirectional UNI Unidirectional Step 1 b Creating Cross connections timeslot based ZBRA CRCT 98 0 CRCT 99 0 BW 32 BI Timeslot based circuit handling 98 0 151 in 99 0 tsl out BW Bandwidth BI Bidirectional UNI Unidirectional Verification Step 2 Verification In order to list all active Cross connections and their descriptions type 9 18 You can also list individual connections Connections must be always listed by defining range of timeslots involved in connections For example ZRBI CRCT 73 0 COM RBI CRCT 73 0 COM EXECUTION STARTED 73 537 BI 2009 11 19 12 49 58 CONNECTION NAME Sonja35 BTSUS1 1 POINT TO POINT CONNECTION 5 0 POINT TO MULTIPOINT CONNECTION 5 COMMAND EXECUTED CIRCUIT IN CIRCUIT OUT BW TYPE 16 CREATION TIME STATE Step 3 Deleting Cross connections Monitor connections can be deleted by defining the PCMs or timeslots that the connection is involved in Command used for this task is ZRBP Delete Multichannel Connection For example ZRBP PCM 98 PCM 99 Or ZRBP CRCT 98 0 CRCT 99 0 BW 32 1 4 Monitor connections Step 1 Creating Monitor connections 10 18 Monitor connections are configured under menu item System Supervision gt Transmission Line Test Handling ZYL Command ZYLE creates a
25. In order to achieve proper testing conditions there must be a possibility to monitor connec tions and circuits that are created through SXC T Nethawk is a licensed program used to capture and analyze GSM network traffic from various interfaces Nethawk is somewhat similar to its TCP IP counterparts for example Ethereal It is installed on a standard PC and capturing is typically enabled by using a switch to duplicate and forward the traffic to the Nethawk port Monitor connections will be set up through the device as SXC T is capable of duplicating traffic for testing purposes At all times during the actual implementation regular safe copies of the running software configuration must be taken and documented the changes made to hardware and soft ware will be documented in order to keep track of changes and possible consequences Af ter all nobody in NSN Tampere knew how the device should be configured and operated Student kept track of the changes by collecting all commands fired and the execution out puts into a notepad file Planning phase also included the preliminary allocation of SXC T interfaces Approximate number of needed ET cards and the amount of to be connected devices and interfaces were calculated SXC T layout and planned ET allocation is described in figure 12 below Many ET cartridges were left idle for possible future expansions TT S 1 L sis w W D A OMU T Figure 12 Layout of the three
26. M viestint tekniikka kytkent isyys Foreword Working on this thesis was a very challenging task It was demanding to learn and under stand the framework of new technology but implementing knowledge in practice while uti lizing the existing network expertise required competence There were also many setbacks and interruptions during work process Few times it was even necessary to revert back to factory settings and recreate configuration Afterwards I am pleased to say that learned skills and experience from such task can provide to be valuable know how in the future This thesis report summarizes the main points during the work process The quick reference guide user training PowerPoint slides and circuit chart are a part of device main tenance and thus a part of this documentation These documents can be found as appendi ces On behalf of Nokia Siemens Networks I would like to thank Mikko Haapaniemi Sakari Ketola Juha Kuusisto Toni Honkanen and all other colleagues who were helpful and with out whom this thesis could not have been completed in its current state I would also like to thank Harri Hakonen who is the supervisor of thesis from Tampere University of Applied Sciences Tampere March 2010 Perttu Haverinen Table of contents I OEM net ide RES ERROR hA ten tend aus 6 2 Background information and goals of thesis sese 7 2 1 COMPANY EM Es 7 222 Thesisbackernoundu a pP 7 3 Global Sy
27. N j a iee Networks Pa 8 SXC T Manager SXC T Manager ET Status View Mais Edit Configure Alarms Views Options na MMLCommandFile Window Help s Change Nokia Siemens N Networks For internal use only ee mw 19 Nokia Siemens Networks 8 SXC T Manager SXC T Manager Cross connections View ad mey Edit Alarms Views MMLCommandFile Window Help 2009 09 10 11 24 16 Taru32 _Liisa535 2009 09 10 11 24 18 Taru34_BT5126 MON Test Circuit 403 2009 09 10 11 24 19 Taru35 BTS126 2009 09 10 11 24 20 Taru36 84 2009 09 10 11 24 22 Taru3 85 2009 09 10 11 24 23 Veera256 Liisa520 2009 10 01 13 56 24 Veera258 BTSU111 2009 09 10 11 24 26 Veera259 BTSF104 2009 09 18 11 33 02 Helga32 Liisa532 2009 09 15 12 42 22 Hulda256 Liisa536 2009 09 24 11 15 15 HULDA258 BTSU84 MON Test Circuit 394 Nokia Siemens Networks S For internal use only 20 Nokia Siemens Networks 9 Backup policy MASTERFB a backup of current system state DATAFB taken every Friday 23 00 automatically e Manual backup eg 201009 taken every other month PARAMETERS LISTING PARAMETER LISTING FORM 2009 10 21 13 53 38 QUE USER DATE TIME NBR PNBR PTYPE DATAFE ELC SYSTEM 2009 10 06 15 00 1 DATAFE ELC SYSTEM 2009 10 09 23 00 FOREV 2 Nokia Siemens Network N e 5 Q a MT Networks B 10 Documentation Manufacturer device documentation
28. SXC T is called Man Machine Interface MMI and the interface language is Man Machine Language MML MML is based on the International Telecommunication Union ITU recommendations ITU T Z 301 Z 341 standards Nokia Networks 2000a 32 The command interface consists of three different levels They are command class command group and individual command Possible command parameters vary depending on the type of inserted command From the main menu level user selects the command class by typing the corresponding let ter The second menu shows the command groups in that command class The third menu level shows a list of commands in that command group SXC T main level command menu is displayed in figure 9 MAIN LEVEL Lum DISPLAY MENU t ALARM SYSTEM ADMINISTRATION B gomme SYSTEM SUPPORT AND COMMUNICATION _ pe aaa a 8 SYSTEM ADMINISTRATION amp NETWORK ADMINISTRATION one ROUTING ADMINISTRATION UNIT ADMINISTRATION M aa SYSTEM CONFIGURATION ADMINISTRATION Vis serres SYSTEM SUPERVISION AES swam END DIALOGUE DESTINATION SELECTION Figure 9 The main level menu in MML session 19 39 There are three different alternatives for managing SXC T Graphical manager software called SXC T Manager can be used remotely via network or as local stand alone implementation The program will be used in NSN laboratory and is dis cussed it in detail later on Local Input output
29. TED Nokia Siemens W Networks For internal use only a i SN 12 Nokia Siemens Networks W 7 OMU Telnet via IP using a Cocen plug in unit in OMU e Steps 1 Create plug in 2 Create ethernet terminal 3 Assign IP address 4 Assign default gateway 5 Assign allowed applications telnet ftp ia Si Work sk ww Nok Net For internal use only ww 13 Nokia Siemens Networks N 8 SXC T Manager trsrvO20 bsc testiteam 28 sxct SXC ManagerC31 Nokia General Communication Service GCS must be installed first Nokia siemens di 2 Networks 8 SXC T Manager SXC T Manager Manage Edit Configure Ala Connect Set IP address TTM Connect to node and load configuration Disconnect Make changes to configuration Send Different tasks are accessed ie Manage Edit CASE Alarms Views Options Testing ILC through different views Eross connections Trunk Lirie Protection Connection Protection 2Mbit s Statistical view 153 01 64 MML Session wiew 125 01 128 125 37 ET 192 222 Test Details view 091 37 ET 256 in 029 01 ET 320 nokia Netw N N For internal use only a s lt NN 15 Nokia Siemens Networks 8 SXC T Manager Add Transparen Modify S Add Connection Prote
30. Tampere University of Applied Sciences Bachelor of Business Administration Business Information Systems Thesis work Implementation of a digital cross connect switch to a GSM network testing environment Thesis Supervisor Lecturer Master of Science Harri Hakonen Commissioned By Nokia Siemens Networks supervised by Senior Specialist Mik ko Haapaniemi Tampere 03 2010 Tampere University of Applied Sciences Bachelor of Business Administration Business Information Systems Author Perttu Haverinen Thesis Implementation of a digital cross connect switch to a GSM net work testing environment Pages 39 Graduation time March 2010 Thesis Supervisor Harri Hakonen Co Operating Company Nokia Siemens Networks Abstract Purpose of this thesis was to implement a Nokia Digital Cross Connect Switch for Time Division Multiplexing SXC T device to a telecommunication testing laboratory Thesis work was done in local Nokia Siemens Networks corporation site in Tampere Finland SXC T acts as a device that interconnects network elements and enables dynamic software based switching and creation of circuits Tasks of device are similar to a typical IP network packet switch but with enhanced features It provides the scalability and flexibility which are important attributes for laboratory conditions that are under constant modification An other goal of thesis was to provide hands on training and device user manual to staff so they could administ
31. Verification ZWTI P OMU COCEN WTI P OMU COCEN EXECUTION STARTED READING DATA FROM DATABASE OMU IN LOC 1C063 37 COCEN 7 TRACK 12 MS 80800000 ME SOSFFFFF IE INT 34H 06750002 TOTAL OF 1 UNITS 1 PLUG IN UNITS AND FUNCTIONS COMMAND EXECUTED ZOHI QHI SEC DX220 L B 2009 08 18 10 55 51 INTERROGATED ETHERNET TERMINAL DATA PIU PIU INTERFACE PHYS UNIT TYPE INDEX TYPE CHAN NB INFO om 00 2 TWISTED PAIR TERMINAL NOT IN USE COMMAND EXECUTED ZORI 11 18 EXECUTION STARTED SXC DXZZ LAB 2009 08 18 10 57 28 INTERROGATED NETWORK INTERFACE STATIC INTERFACES IP ADDRESS UNIT STATE TYPE MTU NETMASK LENGTH PIU FRM ROU OMU UP ETH 1500 10 8 189 175 24 DIX 1 COMMAND EXECUTED ZQJA OJA SXC DX220 LAB 2009 06 16 10 58 41 INTERROGATING SERVICE DAT SERVICE NAME PORT TYPE UNIT FAM PROC ADDR STATE FTP 21 TCP OMU OOOOH WO TELNET 23 TCP 0098H OOOOH WO UP COMMAND EXECUTED ZORL ORL EXECUTION STARTED SZC DXZZ LAB 2009 08 18 10 59 43 INTERROGATING ROUTE DATA NBR UNIT DESTINATION NET IF NEXT HOP PRI STATE 0 OMU DEFAULT ROUTE EIH 4 10 8 189 1 100 COMMAND EXECUTED 2 0 SXC T Manager C3 1 2 1 Setup and install Step 1 Installing software SXC T Manager version C3 1 can be found from the following network location 12 18 13 18 trsrvO20 bsc_
32. XECUTION STARTED CIRCUIT IN CIRCUIT OUT BW TYPE 16 CREATION TIME 98 1 99 1 Sd BI SIGN 2009 08 17 13 59 18 1 POINT TO POINT CONNECTION 5 POINT TO MULTIPOINT CONNECTION 5 COMMAND EXECUTED Nokia Siemens work S Networks N internal use only a i Nokia Siemens Networks 6 Monitor Connections Ms Switching Incoming circuit Matrix Outgoing circuit 5 x 64 kbits CRCT 74 5 CRCT 75 5 5x64 kbit s connection connection Monitor connection types Monitor connection Split connection Key Test port TPN 1 Test equipment Connection loopback participating ETS in same mode Figure 17 Series split connection Switching 1 _ Matrix ET CRCT 68 17 15 x 64 kbit s i 15 x 64 kbit s connection connection Key Test port TPN 1 l ii Test equipment Figure 16 Monitor connection for a bidirectional connection N gt af For internal use only 11 Nokia Siemens Networks 6 Monitor Connections ZYL Transmission line test handling command Example circuit to be monitored PCM 80 PCM 250 Test nethawk PCM 400 401 CIRCUIT IN CIRCUIT OUT BW T16 556 32 SB LE PCM 60 PCN 250 PCM 400 IN TIME 0 Sud PORT CIRCUIT LIMIT TYPE YLE PCM 80 FCM 250 FCM 401 0UT TIME 0 403 HON TEST CONNECTIONS 5 MONITOR CONNECTION 5 SPLIT CONNECTION S CONNECTION LOOPBACK S COMMAND EXECU
33. ace located on top of SXC T rack Verification output of synchronization state and clock time is displayed in figure 16 28 39 SXC DX220 L B 2009 10 01 11 55 42 INPUT STATE USED INPUT PRIORITY 2M1 DISCONNECTED 2M2 DISCONNECTED gt 2M3 DISCONNECTED FS1 CONNECTED Li Leke k TLL AAA ELI FUNCTION AUTOMATIC USE OF REPAIRED INPUTS hin ihn cn ln c ON SYNCHRONIZATION UNIT D OSCILLATOR CONTROL WORD VALUE 31123 SYNCHRONIZATION UNIT 1 OSCILLATOR CONTROL WORD VALUE 28698 SYNCHRONIZATION UNIT D OSCILLATOR CONTROL MODE NORMAL SYNCHRONIZATION UNIT 1 OSCILLATOR CONTROL MODE NORMAL TIMER SYNCHRONIZATION SIGNAL MALFUNCTION TOLERANCE TIME 1 MIN TIMER REPAIRED SYNCHRONIZATION INPUT OBSERVATION TIME 1 MIN COMMAND EXECUTED Figure 16 Correct date and hierarchic synchronization state revealed that synchronization was cor rectly configured One of the biggest concerns were erroneous unit states and alarms in SXC T One SCU Switch Control Unit was not working and the unit state was faulty Another SCU was working but since the idea of having two units is to provide fault tolerance and automated switchover capability if other unit fails it was important to get it fixed Also Operation and Maintenance unit suffered instability issues by randomly performing system resets
34. ainly used in Nordic countries Baltic countries and Russia while other countries developed standards of their own that would not be com patible with each other In 1982 the development of a pan European standard for 900 MHz digital cellular mobile radio was started by the Groupe Sp cial Mobile of the CEPT Conf rence Europ enne des Administrations des Postes et des T l communications Initially the acronym GSM was also derived from the name of this group Ebersp cher V gel Bettstetter amp Hartmann 2009 5 Penttinen 2000 11 GSM networks officially launched during summer 1992 and the number of subscribers increased rapidly such that in the fall of 1993 already more than one million subscribers had made calls in GSM networks more than 80 of them in Ger many One of the key success factors for GSM was that the standardization work was not fully completed at the time of launch It was initially decided that GSM would evolve over time With improvements in computing and radio access technology GSM will offer continuous improvement and more services On time these were called Phase 2 and Phase 2 fea tures which included additional supplementary services improved short message services and improvements to radio access and SIM Subscriber Identity Module cards Nokia Networks 2000b 12 Today GSM also includes packet switched data transfer method called GPRS General Packet Radio Service and is generally called as
35. ampere University of Applied Sciences Bachelor of Business Administration Business Information Systems Author Perttu Haverinen Thesis Implementation of a digital cross connect switch to a GSM net work testing environment Pages 39 Graduation time March 2010 Thesis Supervisor Harri Hakonen Co Operating Company Nokia Siemens Networks Tiivistelm T ss opinn ytety ss tutustutaan digitaalisen ristiinkytkent laitteen asennukseen matka puhelinverkon testausymp rist n Laite on Nokia Networks Oy n valmistama Nokia Digi tal Cross Connect Switch for Time Division Multiplexing SXC Ty suoritettiin paikal lisessa Nokia Siemens Networks yhti n toimipisteess Tampereella SKC T toimii verkossa laitteena joka yhdist eri verkkoelementit toisiinsa ja tarjoaa dynaamisen ohjelmistopoh jaisen k ytt liittym n yhteyksien hallinnointiin ja luomiseen Laitteen k ytt notolla mah dollistetaan tyypillisesti muuttumattoman matkapuhelinverkkoymp rist n soveltuvuus tes tausk ytt n jolloin silt vaaditaan erityist muutosalttiutta Opinn ytety h n kuului lis k si laitteen k ytt koulutuksen tarjoaminen Opinn ytety n toteutus koostui monista eri vaiheista jotka luovat my s pohjan t lle doku mentille Johdannon j lkeisess kappaleessa tutustutaan opinn ytety n taustoihin tavoittei siin ja perustietoon Nokia Siemens Networks yhti st Koska SKC T asennetaan GSM Global System for Mobile communications
36. ction Delete Connection Protection 5 connections View SIGN 2009 08 17 13 59 18 Status Changes Functional Type Bi Direction 64 12 F Nokia Siemens Networks For internal use only UP 16 Nokia Siemens Networks 8 SXC T Manager Nokia Siemens ps internal use only a ww Nokia Siemens Networks 8 SXC T Manager E SXC Manager SXC_T 10 8 189 175 Manage Edit Configure Alarms Views Opti Testing MMLCommandFile Window CONNECTION VIEW SXCT 1 153 37 153 01 ET iA e 125 37 192 ear 001 01 ET 384 ET 452 CC 453 ET 454 ET 455 Add Transparent Cross connection Delete Transparent Gross connection 68 69 70 Hi ai o O 15 125 37 ET 576 091 01 ET 640 091 01 ET 640 063 37 ET 896 a pa ET 456 ETE 45 45 45 460 461 462 D acd Add Trunkline Protection Delete Trunkine Protection 73 ET 74 ET8 75 76 ETE 77 ET 78 Functional Modes Statistics Window Delete Test Connection Connection Details J Nokia siemens N etworks
37. d UMTS coverage UMTS is sometimes referred to 3GSM because of their close technical relationship GSM Association 2009b 3 2 Fundamentals of GSM network architecture and operation In order to understand the function of digital cross connection in GSM environment it is essential to familiarize the basics of GSM network technology GSM uses Time Division Multiple Access TDMA Frequency Division Multiple Access FDMA and Frequency Division Duplex FDD techniques in its radio interface TDM Time Division Multiplexing is a technology that allows multiple signals or bit streams to be transferred apparently simultaneously as sub channels in one communication channel but are physically taking turns on the channel Nokia Networks 2000b 128 TDMA is an extension of TDM that allows each user to either transmit or receive bursts of information only in the allocated timeslot Nokia Networks 2000b 128 Figure 3 de scribes the functionality of TDMA 10 39 Time Slot Bursts f i Bursts from Mobile Stations 2Mbit s to BSC Figure 3 Data stream consists of TDMA frames A TDMA frame is further divided into eight time slots Source Nokia Networks 2000b 141 Standard GSM network consists of three subsystems Network Switching Subsystem NSS Base Station Subsystem BSS and Network Management Subsystem NMS Mo bile Stations MS or in other words mobile phones are needed to be able to use network services MS
38. d for much greater time span Nokia Siemens Networks is a multinational company The reason why thesis was written in English was that it could be used as a guideline in possible future SXC T installations Soon after our device was operational installation of another SXC T begun in adjacent testing department in NSN Tampere Documents written by student were helpful guidance and some on site configuration support was also provided This example proves that thesis documentation written in English can be used as a guideline during possible future installa tions in NSN sites all around the globe Student himself was very pleased with result of thesis in total In addition to successful work outcome the process was very educational As the trend today is to unite different network technologies and areas to work in one operational IP network core knowledge of both telecommunication and IP networks is very useful Also the thesis was important to employer and therefore the motivation to finish it fully completed and in schedule was high Command line interface and individual commands are not explained elaborately in docu mentation This purpose is served by additional user guide created by student which is at tached to this thesis as Appendix 2 However it is designed for test engineers that are al ready familiar with GSM technology and GSM network equipment configuration Student didn t find it relevant to explain the diverse configuration paramete
39. e Pages 18 2 18 SXCT Service Cross Connect for Time divison Multiplexing Quick Reference Guide 1 0 Using MML ice ass 5 VEET CGH UE OE WAA WAA AAA ns rence lee 5 1 2 LOUD mm 7 1 3 C FOSS COBHBeCEOTIS AA Asma sss asa usta 8 I Monto CONNECUONS S H 9 Cocena TCP IP ev alt Rte AA 10 DAES XE T Nager m He ob nit EE u ids 12 2 1 SUP ARA metallo skies dues m ode Sa m at ME LENT a ne UNI LM 12 2 2 Configuring m s n aisan RESORT UO UR WA 14 2 3 CTOSS CONNECHONS S oot deter ett S at KANU AWA 16 S O Backup POMC ai AI m Mi durada a m ien 18 4 18 5 18 1 0 Using MML 1 1 ET Configuration Step 1 Creating ET plug in unit Et plug in units are created with ZWTP command ET number track index function bandwidth PCM and timeslot options must be configured Even ET s require an additional control PCM while the odd are configured with only one PCM Control PCM number is cartridge based and timeslot corresponds to the track number The other PCM number corresponds to ET number and used timeslot is 0 ZWTP ET 98 ET2E 0 17 ZWTP ET 99 ET2E 0 17 00 4 12 TSL 17 ETTOO 4 98 TSL 0 00 4 99 TSL 0
40. e additional phases required when compared to a single MML command Based on opinions from colleagues user guide document was to be a rather simple explanation of each command accompanied by screenshots for clarification User guide is attached to thesis report as Appendix 2 In addition to the quick reference guide student was asked to make a short presentation to all test engineers so everyone would know how to configure circuits and ET s on their own 34 39 35 39 The presentation itself was a very educational as much for student as it was to audience Key features of equipment were introduced and among the user guide a PowerPoint pres entation served as a backbone for the presentation It lasted for about an hour and questions from listeners were answered during it The PowerPoint is attached to thesis as Appendix 3 7 Conclusions Thesis goals were to have an operational SXC T digital cross connect switch in testing laboratory by August 2009 Circuits in switch were to be functional and management was to be remotely done using company LAN Test engineers should have a sufficient level of knowledge in order to operate the device Device maintenance plan and documentations would provide security and ease of maintenance for the future The most challenging time during the process was the beginning I was given a fair amount of technical details and manuals that I could barely understand While trying to figure out the layout and deta
41. ectories However on the long run only one updated backup would be insufficient and possibility of corrupted package would be far too large Matter was discussed among student and test engineers and solution was to commence au tomatic incremental DATA backup using one directory and to manually take and docu ment a FULL backup to another directory every two months for increased security Also we took a foundational backup called MASTERFB FB Fallback from current system state that would not be overwritten This way the possibility of a corrupt backup file and forced rollback to a file that is not up to date is minimal A backup copy command execu tion is displayed in figure 22 WKS MODE FULL NAME MASTERFE DIRE MASTERFE FULL FALLBACK COPYING STARTED FB PACKAGE MASTERFB DIRECTORY MASTERFE COMMAND EXECUTED AND FUNCTION STARTED Figure 22 Command execution of a full backup file named MASTERFB For a continuous scheduled backup task multiple steps had to be taken First we needed to create a file containing the command that could be attached to command calendar also known as command file This file can be seen in figure 23 In figure 24 the created file is attached to command calendar and assigned with execution date time interval and number of executions You can also see the other definable parameters We decided to roll the backup on Friday 23 00 every other week on a non business hour with infinite number
42. er the device independently Thesis process consisted of phases that serve as a baseline for this document Second chap ter discusses the background of thesis and general information about Nokia Siemens Net works as a company SXC T is installed to GSM Global System for Mobile communica tions testing laboratory GSM standard and technology is discussed in chapter three We also take a closer look at the elements of GSM network that are connected through SXC T In chapter four SXC T device composition and hardware are reviewed in order to under stand device functionality Planning and execution of SXC T installation followed by user training are examined in chapters five and six Thesis outcome evaluation and final conclu sions are discussed in chapter seven As a result of this thesis Nokia Siemens Networks has a functional digital cross connect switch in active use Training and manuals supplied by student guarantee that every user has sufficient know how for device operation Documentation is shared in company net work drive so everyone can update material as needed Backup plan was also created to provide fault tolerance and security for this crucial network equipment Material used in thesis was mostly device manufacturer documentation educational books and company slideshow presentations Many of the solutions were result of hands on trou bleshooting and discussion with colleagues Keywords GSM telecommunications switching T
43. ere problems and delays in dif ferent phases of implementation caused by inexperience and hardware issues work was still in schedule However documentation was currently based on temporary notes for most part and needed contribution Circuit chart was planned to be made on Excel sheet and then shared in company s network drive After SXC T user training each test engineer could keep the sheet updated for circuits they manage Updated documentation is a vital part in order to keep track of circuits and connections Circuit chart for this SXC T device was cre ated by student and is included in thesis as Appendix 1 32 39 To avoid irreversible node failure or invalid configuration causing instability there was a need for a backup plan Backups taken irregularly without any control or documentation would not provide required degree of security SXC T like BSC s and other DX200 plat form equipment include a command calendar option which can be used to assign scheduled tasks However the matter is problematic SOMAFI is a file that contains indexes for all the created packages in a DX 200 platform It allows only eight system backup packages to ex ist simultaneously even though hard drive was far from full Because of this taking auto matic backup for example every two weeks would fill SOMAFI index very quickly There is also an option for DATA incremental type backup which overwrites data files and saves settings without creating additional dir
44. ermanently location updated by VLR e Stores SIM card parameters allocated by operator Equipment Identity Register e Provides security to GSM network together with AuC A database containing a list of all valid mobile equipment in network Banned or monitored mobiles are indenti fied by IMEI The International Mobile Equipment Identity IMEI is a unique 12 39 13 39 number sequence located in every mobile and be therefore used to stop blocked or stolen phones from accessing the network Authentication Centre e Authentication and key management Group Call Register e Enables conference calls provided by GSM network Not essential but optional for basic GSM network operation 3 2 2 Base Station Subsystem BSS The Base Station Subsystem is responsible for radio path control in GSM It consists of the following elements Base Station Controller BSC Base Transreceiver Station BTS and Transcoder TC In NSN Tampere BSC program mainly focuses on BSC feature testing BSC is the central network element of the BSS and it controls the radio network Main functions are connection establishment between mobile and NSS mobility management statistical raw data collection and signaling support for and Air interface BTS is a network component that handles the Air interface taking care of Air interface signaling ciphering and speech processing The third component Transcoder is used to code speech into right format between n
45. etwork elements Air interface speech is compressed to 13 Kbit s bit rate full rate or 5 6 Kbit s bit rate half rate from 64 Kbit s bit rate used in PSTN Public Switched Telephone Network which is the standard fixed telephone system used by wired phones A bis is the interface between BTS and BSC and uses the same 13 Kbit s coding as Air interface 3 2 3 Network Management Subsystem NMS The purpose of Network Management Subsystem is to monitor and administer various functions and elements of the network Management is implemented by using workstations and databases that are connected to different network elements NMS has three main func tions fault management configuration management and performance management Fault management ensures smooth network operation and rapid fault correction for operators by utilizing various triggers and alarms Configuration management maintains up to date in formation about the operation and configuration status of network elements It is used to monitor the current and possible new configurations of the network Performance man agement collects measurement data from individual network elements and stores it in a da tabase With this data an operator is able to see if its network meets planned performance levels and if there are rapid changes in performance or differences in performance between various areas 3 2 4 General Packet Radio Service GPRS Circuit switched GSM also offered data service bu
46. ils of the device configuration I finally decided to put device documen tation aside and start from the basics I grabbed myself a Nokia GSM System Training book and studied GSM network technologies in general with help of colleagues I also ob served testing and GSM data monitoring with other test engineers which also helped me in getting familiar with the system Support from outside was a vital part throughout the im plementation and it was necessary to discuss with people responsible for the configuration of other devices Documentation and material used by student during thesis work was mostly manufacturer device documentation supported by books and training materials about GSM networks and technology Therefore the overall material can be concerned fairly reliable as it s mostly facts about GSM standard and its history leaving no room for interpretation Device spe cific documentation produced by SXC T manufacturer Nokia Telecommunications is also from reliable source and up to date Few used online sources include publications from no table Finnish universities and world wide GSM association and are written and inspected by persons with adequate level of knowledge before publication There were numerous problems and standstills during work process Both student and test engineers were unaware of certain configuration parameters and their purposes Support was also asked from other NSN sites and company external sources like Nethawk Corpo
47. ions Base Transreceiver Stations Base Sta tion Controllers Home Location Registers and so on The old testing network consisted of multiple independent and static environments with own hardware and software configuration for each tester according to their needs Testers were working with a BSC and a number of Base Transreceiver Stations connected to it while the rest of the GSM network was formed using shared components TC SGSN GGSN MSC and HLR The implementation of SXC T was planned in parallel with labo ratory equipment rearrangement scheduled to be done during summer holidays Since equipment was going to be moved and reconnected no additional work was needed to in troduce SXC T to the environment Originally the move was planned in order to rearrange test laboratories and relocate test engineers offices Figures 10 and 11 present the logical laboratory environment before and after installation of the device Note that these pictures are only for illustration while the actual laboratory consists of dozens of BTSs BSCs and countless mobile phones 21 39 22 39 gt E o s D Figure 10 Original laboratory environment 23 39 gt 3 s m xX gt gt X gt x K Xo 4 4 5 13 N gt sa BH O NS99 Figure 11 SXC T implementation
48. ive You can also find the commands under Configure tab In transparent connections you select the start and endpoint PCM z SXC T Manager Manage Edit Configure Alarms Views E end SUN MMLCommandFile Window Help int Cross connectiony Add Connection Protection Delete Connection Protection Add Tranki tection ross connections View ene Tes ne ns ceseonpaeewme 99 1 BI SIGN 2009 08 17 13 59 18 Functional Mades 2M Port Names Test Port ET Status Change ET Functional Type ET Port Diagnosis Key Macros Add Transparent Cross connection x 5XC T 10 9 189 175 BiDirection 53 01 ET 64 H125 01 128 17 18 In point to point point to multipoint connections you select the PCM and choose the timeslots to be switched figure below You can also add and remove connections from a multipoint connection afterwards se Cross connections View Ines Lus creation petes Te stats Connection 98 1 99 1 BI SIGN 2009 08 17 13 59 18 90 1 89 5 75 21 Add Point to Multi Point Cross connection ET Time Slots Time Slots Finally the created circuits will be graphically displayed in the Connection View 18 18 The created circuits will be displayed in the Connection View 3 0 Backup policy A proper backup plan is in place in order to ensure and main
49. matkapuhelinj rjestelm n testauslaboratori oon GSM standardista ja sen toiminnan perusteista keskustellaan kappaleessa kolme Sa malla tutustutaan paremmin my s SXC T n l pi kytkett viin verkon elementteihin Kappa leessa nelj k yd n l pi ristiinkytkent laitteen toimintaperiaate ja kokoonpano Itse asen nuksen suunnittelu toteutus ja k ytt j koulutuksen j rjest minen on sis llytetty kappalei siin viisi ja kuusi Ty n tuloksien arviointi ja johtop t kset k yd n l pi kappaleessa seit sem n Ty n tuloksena Nokia Siemens Networks yhti ll on testauslaboratoriossaan aktiivisessa k yt ss toimiva digitaalinen ristiinkytkent laite Asennuksen yhteydess toimitetut k yt t ohjeet ja k ytt j koulutus varmistavat ett ty ntekij ill on valmius laitteen k ytt mi seen Dokumentaatio ja yll pidett v t taulukot on jaettu yhti n sis isell verkkolev yll jo ten dokumenttien p ivitys on vaivatonta Koska laite on koko verkon toimivuuden kannalta keskeisess asemassa sen turvallisuus on varmistettu s nn llisill varmuuskopioilla Ty n eri vaiheissa k ytetty materiaali koostuu p osin laitteen valmistajan tarjoamista do kumenteista yleisest oppimateriaalista GSM verkoista sek Nokia Siemens Networks Oy n yleisist oppimateriaaleista ja PowerPoint esityksist Monet ratkaisut ovat seurausta perinteisist ongelmanratkaisumenetelmist ja keskustelusta kollegoiden kanssa Avainsanat GS
50. mp Rounaja 2009 In Finland Nokia Siemens Networks has sites located in cities of Espoo Tampere and Ou Iu Tampere site employs around 1100 people and is mainly focused on software specifica tion and testing of 2G and 3G technologies and solutions 2 2 Thesis background Tampere site has always been one of the company s most important branch offices for re search and development Its multiple stand alone 2G and 3G mobile network laboratories are used by company internal and external employees both locally remotely Remote con nections can be created even from other side of the world Environments consist of all the segments that a live telecom network needs to operate Though it s essential to maintain testing laboratory equipment up to date with latest hard ware and software usability has not been a top priority when new acquisitions have been made Until now testing environments have been rather static and modifications have re quired a notable amount of effort due to changes needed in cabling This is not ideal situa tion for dynamic testing environment which constantly undergoes rapid changes both in hardware and software to meet the needs for various testing scenarios Earlier changes in cabling were done locally and manually using a cross connect patch panel 8 39 The solution was to install a Nokia digital cross connect switch SXC T to the laboratory The device was acquired from another NSN site located in Finland Once
51. new monitor connection First we define the PCM or Circuits of the monitored connection depending on the type of monitored circuit timeslot circuit based or transparent Next we define the test PCM that the traffic 15 forwarded to A single connection requires two test PCM s in order to monitor both directions of traffic Note All ET s must be in same type of functional mode and type Example ZYLE PCM 66 PCM 556 PCM 403 OUT TIME 0 ZYLE PCM 66 PCM 556 PCM 402 IN TIME 0 Circuit In 66 Circuit out 556 Test ports 402 403 Time limit 0 infinite Verification CIRCUIT IN CIRCUIT OUT Tib 66 556 32 BI TEST TEST TIME TEST PORT CIRCUIT LIMIT TYPE 403 MON 402 TEST CONNECTIONS FROM 5 MONITOR CONNECTION 5 SPLIT CONNECTION 5 CONNECTION LOOPBACK 5 COMMAND EXECUTED Step 2 Deleting Monitor connections Monitor connections are deleted by defining the monitored circuit using ZYLT command The following command deletes all monitor connections involved in ciRcuit 66 556 ZYLT PCM 66 PCM 556 1 5 Cocen TCP IP Step 1 Creating Cocen plug in unit ZWTP OMU COCEN 7 12 Step 2 Creating Ethernet terminal ZQHC OMU COCEN 7 TPI Restart Step 3 Assigning IP address QRC OMU ETH 7 10 8 189 175 24 STA UP FRM DIX Step 4 Creating and allowing application ZQJG TELNET OMU UP Step5 Assigning a default gateway ZORR OMU ETH 7 10 8 189 1 UP
52. ove the existing testing environment with imple mentation of a digital cross connection switch designed for telecommunication networks The testing environment in the laboratory consists of the same equipment that is used in live GSM networks throughout the world In short lots of expensive space and resource consuming equipment located within relatively small space Yet it must be adaptable to rapid changes both in hardware and software which is not what these network components are originally designed for This scenario creates a burden on test engineers and administra tors working with the equipment because it requires significant amount of effort before full network is configured to match yet another testing scenario SXC T unit is designed to provide easier equipment management via software based switching of circuits This obsoletes the need for physically altering the equipment and ca bles Necessity of this solution had been known in company for some time yet it was not until recently that they acquired the proper unit that was capable of digital switching While the testing department was loaded with other work the implementation of the SXC T was trusted to summer trainee Assignment was very challenging due to the student s own lack of knowledge in the field of GSM networks However having a strong background in studies in Computer Science and Internet Protocol IP was helpful The SXC T unit is developed by Nokia Corporation and is u
53. physical connec tivity is established to SXC T the switching and creation of connections or in other words circuits is software based This means that manual changes to cabling are not needed any more Every person in the testing team can operate and modify the switched circuits re motely as long as they are connected to the company LAN 3 Global System for Mobile communication 3 1 GSM in brief Throughout the history people have had various means to communicate with each other from distance The first portable personal transreceivers were clumsy and were mainly used by authorities and professionals In Finland the first introduced mobile wireless technology to gain public popularity was ARP Autoradiopuhelin in 1971 which was in use to all the way to the end of year 2000 The system had its peak rate of users in the mid 1980 s with over 30 000 end users Karvonen 2005 While in ARP once the call was made the user had to remain within the same geographical area served by the particular base station If the user would move far enough the call signal would deteriorate and eventually break up Next step was the first generation of modern mobile communication system also known as 1Gor mobile telephone The system was introduced to Nordic countries in 1981 Penttinen 2000 11 It provided fea ture that allowed users to move freely while talking on the phone by utilizing automated network cell changes However NMT was m
54. ra tion when the case was that traffic monitoring tools in SXC T were not working properly Two of the time consuming problems were due to faulty internal cabling configuration which was solved with help of members from team that was responsible of laboratory equipment and hardware Though device manuals were of good quality there was no way the work could have been solely based on them Few delays were caused by late hardware and cabling equipment shipments from third party vendors as well In all targets were achieved in schedule right before new software release was about to enter testing phase There were some pressures concerning completion of thesis during final stages because testing could not be started before digital switch connecting the test envi ronments was fully up and running At this point student decided to make the SXC T opera tional first Future usage and time span of device is yet unknown However such a major change in en vironment wouldn t have been carried out if it was for short term use only Though some might consider SXC T another possible source of errors in network topology it is well known for its stability once it is fully operational It needs no additional maintenance ex cluding manual backups Once IP technology is taken further into 2G technology it obso 36 39 37 39 letes the need for PCM digital switch However this will not happen in the next few years to come and legacy testing is still neede
55. ration to be able to confirm correct link functionality on both end devices After a successful trial laboratory staff commenced full scale physical device connections through SXC T Once again a backup was taken before any further steps Stu dent was left with task of documenting and creating all circuits that would pass through de vice 6 5 Graphical user interface Software designed for SXC T management was acquired from Nokia Siemens Networks site in Espoo It s called Nokia SXC T Manager version C3 1 Setting up the manager was easy and the instruction manual that was delivered with software was well defined First the program was supplied with device IP address When connection was established program automatically detected available ET s computer units and their statuses existing circuits alarms and so on While manager included most of the routine configuration tasks including ET mode and state changing monitor connection and alarm log handling and cir cuit managing it soon became clear that it lacked many fundamental configuration options These were for example computer unit management diagnostics circuit group backup file and operating system management Figure 20 is an example view of program main window sxc T Manager SXC_T 10 8 189 175 Manage Edit Configure Alarms Views Options Testing MMLCommandFile Window Help EQUIPMENT VIEW CONNECTION VIEW
56. rators that have network equipment scattered across vast geographical areas In GSM the off air transmissions are carried out using 2 Mbit s PCM Pulse Code Modula tion link method Physical media can vary from coaxial or optical cable to satellite links and the link protocol used can be for example Ethernet or ATM Penttinen 2000 92 PCM has been used for digital representation of analog signals since the implementation of digi tal telephone systems in 1980 s Single PCM timeslot can transfer traffic at a rate of 64 Kbit s European standard for PCM transfer rate is 2 Mb s or 32x64 Kbit s 2 2048 Kbit s In this case 32 timeslots are used to carry data For example the American standard transfer rate for PCM lines is 1 5 Mb s since only 24 timeslots are used Penttinen 2000 93 Digi tal cross connect switch in NSN laboratory is fitted solely for 2Mbit s PCM line switching purpose 4 2 SXC T Product description and composition SXC T is a component manufactured by Nokia Corporation It is based on the popular DX 200 platform that was developed by Nokia in 1978 DX 200 was the first microprocessor controlled telephone exchange and acted as a digital replacement for analog mobile ex changes While it has gone through major technical upgrades it is still being globally used today SXC T is only one implementation of the platform Other network elements based on DX 200 design are Nokia BSC MSC and SGSN Conversion capability is provided b
57. rk Switching Subsystem Figure 5 GPRS capable GSM network 14 39 4 Nokia digital cross connect switch SXC T 4 1 Digital cross connect switch in a GSM network Today there are different types of digital cross connect systems They can be found in Frame Relay ATM MLFR Multi Link Frame Relay and PCM Pulse Code Modulation based networks SXC T is a digital cross connect system for circuit switched networks that uses TDM TDM was discussed in detail in chapter 3 2 If we compare a digital cross connect switch to a typical IP network packet switch the main difference is that instead of individual packets it switches circuits The rest of the operational principles could be con sidered roughly the same in both devices Circuits are usually switched for greater time spans typically months or longer as compared to packet switches which can operate on micro or millisecond time spans Additional SXC T features include hard drive back up and file management alarm management monitor and test connections and many more In GSM networks circuits are switched between network elements such as BTSs BSCs MSCs SGSNs and so on Digital cross connect provides redundant adaptable and high availability environments It is most effectively used in large network junctions because it can provide up to thousands of interconnecting ports Nokia Networks 2000a 15 A de vice capable of remote administration and switching is a vital feature for ope
58. rs and MML commands in detail to reader 38 39 References GSM Association 20093 GSM World Market Data Summary online referred 18 06 2009 http www gsmworld com newsroom market data market data summary htm GSM Association 2009b GSM World Poster 2009A online pdf referred 25 06 2009 http www gsmworld com roaming GSM WorldPoster2009A pdf Lileg Ruth 2009 Nokia Siemens Networks market leadership pdf Nokia Siemens Net works Lileg Ruth amp Rounaja Saara 2009 Nokia Siemens Networks company presentation June 2009 3b ppt Nokia Siemens Networks Karvonen Erkki 2005 Johdatus viestint tieteisiin Viestinn n historiaa S hk isen me dian historiaa online referred 24 06 2009 http www uta fi viesverk johdviest viesthistoria sahkomedia html Ebersp cher J rg V gel Hans J rg Bettstetter Christian amp Hartmann Christian 2009 GSM Architecture Protocols and Services 3rd edition United Kingdom West Sussex John Wiley amp Sons Ltd Penttinen Jyrki 2000 GSM tekniikka J rjestelm n toiminta palvelut ja suunnittelut 2nd edition Helsinki WSOY Penttinen Jyrki 2001 GPRS tekniikka Verkon rakenne toiminta ja mitoitus 1st edition Helsinki WSOY Penttinen Jyrki 2006 Tietoliikennetekniikka Perusverkot ja GSM Ist edition Helsinki WSOY Tisal Joachim 2001 The GSM Network GPRS Evolution One Step Towards UMTS 2nd edition United Kingdom West Sussex
59. sed by service providers which means that the command interface and operation of the unit are not designed as user friendly as compared to commercial network equipment It also lacks the extensive technical support that is available for standard market products NSN personnel were not familiar with SXC T equipment Resolution was that extensive amount of background work had to be done involving GSM technology and SXC T opera tion 7 39 2 Background information and goals of thesis 2 1 Company In 2007 Nokia Networks and Siemens Communications departments joined operations in order to gain competence and combine know how from both parties Nokia Siemens Net works was formed and it is jointly owned by parent companies Today NSN employs around 60 000 people in more than 150 countries and serves over 600 operator customers NSN is currently the world s second largest telecommunications supplier after Ericsson Lileg 2009 2 Figure 1 displays some major sites and operator customers e ru er Mex Me e vu pecu e TELECOM S cingular e s ed atat sw E wm 1525 pem CABLE Chino FR TELMEX Idea G Chunghwa Telecom Nitel Sas N TELKOM E xk indosat am ricas gt mavu TL Hutchison Telecom E e Telstra Figure 1 NSN global presence and major customer references Lileg a
60. stem for Mobile communication 9 3 1 GSM IQ brief Rate era 9 32 Fundamentals of GSM network architecture and operation 10 3 2 1 Network Switching Subsystem NSS 12 3 2 2 Base Station Subsystem BSS Avice OG er Re 13 3 2 3 Network Management Subsystem NMS 13 3 2 4 General Packet Radio Service GPRS 14 4 Nokia digital cross connect switch SXC T 15 4 1 Digital cross connect switch in a GSM network 15 4 2 SXC T Product description and composition esee 15 4 2 1 TDM switelumg module sa sy aa donnee Nue 17 4 22 Int erfaee MOM C nn ete 18 4 2 3 Operation and Maintenance module 18 4 3 SXC T management and configuration 19 5 Planning of SXC T implementation ot auma NAT A mount 21 EXeCULHOD nopne besote ce Ge Oy 26 6 1 Enabling IP connectivity ni u S 26 62 Replacing old Bard un a n a mana ua 27 63 Reworking basic software configuration ss 28 64 Building up new environment ceste rates 30 6 5 Graphical user ab Eoo iae n au 31 6 0 Nethawk and monitor
61. t with inadequate data rates of 14 4 Kbit s Later on an extension was introduced which enabled utilization of three timeslots and a total of 43 2 Kbit s Also the circuit switched nature of the service was far from ideal for bursty data traffic flow These were the main reasons why standardization for GPRS began in mid 1990 s Penttinen 2001 8 13 Operators started modifying GSM networks for GPRS compatibility in year 2000 In order to offer packet switched data service existing GSM network elements required modification and two new elements were introduced This is also current laboratory setup in Nokia Siemens Networks Tampere site so we will go through a brief description of each device Serving GPRS Support Node SGSN takes care of the conversion between IP backbone protocols and BSS protocols In GPRS network topology it s located between BSC and Ga teway GPRS Support Node GGSN SGSN also routes data to the right GGSN performs authentication data compression and ciphering SGSN can interact with MSC Mobile Switching Center via optional Gs interface GGSN can be compared to router in IP network as it manages similar tasks and hides the GPRS infrastructure from external networks It enables data packets to be passed on to oth er packet switched networks such as Internet and also allocates IP addresses to mobile sta tions The architecture of GPRS capable GSM network is presented in figure 5 Base Station Subsystem Netwo
62. tain device functionality and possibility to rollback to a packet that is up to date in case of faulty software configuration or failure Manual Backup eg 011009 a full system backup taken manually every other month Automatic Backup DATAFB is a datafile backup taken every Friday at 23 00 Appendix 3 NSN SXC T Briefing PowerPoint slides Pages 22 Nokia Siemens Networks S For internal use only 1 Nokia Siemens Networks SXC T Briefing Nokia Digital Cross Connect Switch fo Multiplexing me Division N For int N N 21 domes Networks Key features Structure and function ET Configuration Circuit groups Cross connections Monitor connections TCP IP 5 Backup policy 0 Documentation Se amp For internal use only P dis 3 Nokia Siemens Networks 1 Key features e Switching of PCM lines Transparent Timeslot based Point to Point Point to Multipoint E 1 ii Test connections isti Monitor loopback split connections T TA Connection statistics and measurement Connection protection Graphical management tool nokia jd internal use only 4 y uff Nokia Siemens Networks 2 Structure and function Computer units OMU Operation amp Maintenance TSU Trunk Supervision Unit mem EZE S
63. test team_28 sxct SXC ManagerC31 Program requires that you install the Nokia General Communication Service GCS 4 2 Older or newer versions Of GCS might not be supported the GCS is provided in the installation folder Step 2 Connection to node Add connection details to the 5 T over COM or TCP IP This is done from the Manager Options tab under the Options menu You can connect to the node by choosing Manage gt Connect 2 SXC T Manager Manage Edit Configure Alarms Views Options Testing MMLComm WA ali 1 Toolbar w Status Bar Manager Options Customize Colors General Iv Confirmation on send Create a separate MML session Log file V Acknowledge after send Step 3 Loading and saving SXC T configuration After connection is established you need to load the effective configuration from the node Select Manage gt Up Load Configuration SXC T Manager Manage Edit Configure Ala Connect Up Load Configuration Send Disconnect 14 18 When the settings are loaded you can save them for faster access Configuration can be changed in offline and online mode If you make changes to configuration offline you can us the Manage gt Send command afterwards to apply it to the node SXC T Manager SXC T 10 8 189 175 Manage Edit Configure Alarms Views Connect Upload Configuration Send Disconnect Load Ele Save Node File Clase Mode File
64. tions 32 ET cards in one ET64 cartridge were sufficient for this purpose Nethawk PC s were installed to a shelf behind SXC T and they were con nected to company LAN for Windows remote desktop connection Each computer was equipped with a Nethawk NAP Adapter connected to motherboard PCI bus Two PCM lines could be monitored through one adapter so each PC reserved one ET2E card two ET interfaces from SXC T SXC T has a feature of echoing traffic from selected circuit to a specific ET port for monitoring purposes In case of two ET interfaces traffic from other network element is forwarded to the other ET interface and vice versa Both the target ET and monitored circuit can be easily configured to any desired interface Monitoring could be handled both using MML and SXC T Manager program However handling monitor connections in Manager program was rather complicated Example output of a created monitor connection is displayed in figure 21 below CIRCUIT IN CIRCUIT OUT BW TYPE 116 66 556 TEST TEST TIME TEST PORT CIRCUIT LIMIT 403 MON 402 TEST CONNECTIONS 5 MONITOR CONNECTION 5 O SPLIT CONNECTION 5 D CONNECTION LOOPBACK S COMMAND EXECUTED Figure 21 Monitor connection for circuit T 66 ET 556 is forwarded to ET interfaces 402 and 403 A total of 5 monitor connections currently exist on device 6 7 Documentation and upkeep Environment was finally fully operational Although there w
65. works laboratory a special COCEN plug in unit is used in OMU to enable Ethernet TCP IP connectivity Clock system and synchronization are the basis of operation in telecommunication net works Clock is synchronized throughout the system as it is needed when PCM signals are decoded and interpreted Nokia Networks 2000a 29 The Clock Synchronization Unit CLS is supplied with an external clock signal from atomic clock or another network de vice It supplies the signal to Clock and Alarm Buffer CLAB which takes care of alarm reporting and synchronization of other SXC T device racks Telecommunication network elements have a hierarchy in signal synchronization Typically MSC Mobile Switching Center synchronizes rest of the GSM network devices traffic inside GSM network is time stamped and there is a threshold for allowed alteration between clocks Once this threshold is exceeded the problems start to arise This is why synchronization is also nec essary in laboratory environment Switch Control and Interface Supervision Units control the switching network handle the supervision of 2 Mb s interface alarms and internal control of the Clock Synchronization Unit It depends on the size of the node whether the functions are installed on the Switch Control Unit only or distributed between the two mentioned units Nokia Networks 2000a 30 4 3 SXC T management and configuration The user interface used in management and configuration of
66. y the possibility to rearrange platform interiors by mounting different cartridges for different purposes Cartridges contain replaceable plug in units which work in conjunction to form computer units which in turn provide the functionality for each platform Some of these 15 39 computer units are common to all DX 200 implementations such as Operation and Mainte nance Unit and clock Hardware and fittings of a SXC T may vary depending on the purpose and environment it is used in It can be implemented by either using a single or multiple DX 200 racks Racks can be interconnected into one logical device in order to increase capacity In our labora tory implementation of three racks and maximum of 1024 interface cards is used SXC T node can be described using module unit hierarchy The modules required in each SXC T are the TDM Switching Module the Operation and the Maintenance Module and the Interface Module as shown in figure 6 Figure 7 displays the computer units contained by each module Interface Module E Switching Module TDM gt O amp M M e Key O amp M Operation and Maintenance Interface Module IC Interface Control SC Switching Control Figure 6 Functional structure of the SXC T node Source Nokia Networks 2000 20 16 39 17 39 Link Interface Module Switching Interface Module Module TDM 2 Mbit s TDM n x 64 kbit s Interf n x 64 kbit s

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