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System and method for design, tracking, measurement, prediction

1. 1 the distance d may be based on true physical distance from the 3 D site specific model of the environment or may actually represent a relative distance ratio where the physical distance between two points is referenced to a convenient close in free space reference distance as is customary for propagation predictions and is taught in Rappaport Wireless Communications Principle amp Practice Prentice Hall 1996 Propagation delay for network data is predicted for wired networks where components are interconnected by wire either fiber or metal wire by dividing the distance traveled by the propagation speed of the electrical electromagnetic or optical signals in the device which are used to transmit 10 15 20 25 30 35 40 45 50 55 60 65 22 the data For instance data in a fiber optic cable travels at a speed 2 10 meters per second due to dielectric properties of the cable which affect the photons in a fiber optic cable that are used to transmit the data Such photons move at the speed of light in glass which is less than the free space propagation speed Thus if the cable is 200 meters long the transmission delay is equal to 1 10 seconds By using the site specific method of modeling the complete network within the present invention it is possible for the user to simultaneously visualize the network as configured in the environment and see a display of delay and predicted or measured pe
2. 6 253 086 6 285 377 6 289 203 6 311 144 6 317 599 6 326 987 6 330 005 6 337 688 6 338 031 6 356 758 6 393 432 6 408 312 6 442 507 6 470 195 U S PATENT DOCUMENTS Sa a i dd a dd ddd dd dda Bl 1 1998 5 1998 6 1998 6 1998 8 1998 8 1998 9 1998 9 1998 9 1998 10 1998 10 1998 10 1998 11 1998 11 1998 12 1998 1 1999 2 1999 3 1999 3 1999 5 1999 6 1999 7 1999 7 1999 8 1999 8 1999 9 1999 9 1999 9 1999 9 1999 10 1999 10 1999 11 1999 11 1999 11 1999 12 1999 1 2000 2 2000 2 2000 3 2000 3 2000 5 2000 5 2000 5 2000 5 2000 6 2000 7 2000 7 2000 8 2000 8 2000 8 2000 9 2000 11 2000 3 2001 3 2001 3 2001 5 2001 6 2001 6 2001 9 2001 9 2001 10 2001 11 2001 12 2001 12 2001 1 2002 1 2002 3 2002 5 2002 6 2002 8 2002 10 2002 Soliman et al Lingafelter Urbish et al George et al Brockel et al Kuriyan Dulman Cooper et al Hart et al Tonelli et al Liu Tang et al Tonelli et al Dent Berman Butler et al Kost Colwell Chawla et al Krause et al Kosbab Barroux Arpee et al Piehler et al Iwamura et al Pulsipher et al Maynard Feisullin et al Stratis et al Reynolds et al Komara Stancil et al Ephremides et al Stancil et al Tognazzini Hayball et al Heiska et al Lee et al Casto Tekinay Drysdale et al Kawas et al Dumarot et al Lipa et al Maclinovsky Djoko et al Lee et al Holender et al Cohoe et al Soliman et al Ohta et al Sutton et al
3. US 6 973 622 B1 35 computer or server can send instructions to one or more components of said communications network which cause settings or configurations of at least one compo nent to be changed 57 The system or apparatus of claim 56 wherein said site specific representation is three dimensional 58 The system or apparatus of claim 56 wherein said measurement collectors or agents are portable or fixed 59 The system or apparatus of claim 56 wherein said measurement collectors or agents are permanently affixed at locations within said physical space 60 The system or apparatus of claim 56 wherein said one or more performance metrics selected from the group con sisting of one or more performance metrics are selected from radio signal strength intensity connectivity network throughput bit error rate frame error rate signal to inter ference ratio signal to noise ratio frame resolution per second traffic capacity signal strength throughput error rates packet latency packet jitter symbol jitter quality of service security coverage area bandwidth server identifi cation parameters transmitter identification parameters best server locations transmitter location parameters billing information network performance parameters C I C N body loss height above floor height above ground noise figure secure coverage locations propagation loss factors angle of arrival multipath components multipath param eters
4. reflectivity surface roughness path loss models attenuation factors throughput performance metrics packet error rate round trip time dropped packet rate queuing delay signal level interference level quality of service bandwidth delay product handoff delay time signal loss data loss number of users serviced user density locations of adequate coverage handoff locations or zones locations of adequate through put E L system performance parameters equipment price maintenance and cost information user class or subclass user type position location all in either absolute or relative terms 42 The method of claim 37 wherein said measurement data received in said receiving step is obtained manually 43 The method of claim 37 wherein said measurement data received in said receiving step is obtained autono mously 44 The method of claim 37 further comprising the step of storing said measurement data 10 15 20 25 30 35 40 45 50 55 60 65 34 45 The method of claim 37 further comprising the step of updating said computerized model 46 The method of claim 45 wherein said step of updating includes the steps of specifying components from a plurality of different mod eled components which are to be used in said commu nications network said modeled components including descriptions and attributes of a specific component and specifying locations within said space for a plurality of
5. Anderson Wadell et al Preschutti et al Tonelli et al Ghori et al Parantainen et al Greenbaum et al Smith et al Abu El Ata Rappaport et al 455 446 Alexander Tonelli et al Berstis Lee et al Almeida et al Flansburg et al Forthman et al Skidmore et al 702 86 Meyer 6 487 417 B1 11 2002 Rossoni et al 6 493 679 B1 12 2002 Rappaport et al 705 29 6 496 290 B1 12 2002 Lee 6 499 006 B1 12 2002 Rappaport et al 703 20 6 505 045 B1 1 2003 Hills et al 6 625 454 B1 9 2003 Rappaport et al 455 446 OTHER PUBLICATIONS PCS 97 Track 7 Engineering amp Systems Management T Rappaport Propagator vol 8 No 3 Fall 1997 SMT Plus 1 0 User s Manual R Skidmore amp T Rappaport Copyright Aug 1996 Virginia Tech Software by Andrew titled RF Planner dated Jun 17 1997 A user guide titled Andrew Microwave System Planner dated Jul 1999 A user guide titled Andrew Antenna System Panner dated Jun 1999 From Bird s Eye Real time Mapping Software dated Jun 30 2002 IEEE Transactions on Antennas and propagation vol 46 No 8 Aug 1998 Effect of Terrain on Path Loss in Urban Enviroments for Wireless Applications Leonard Piazzi and Henry L Bertoni P Bahl V Padmanabhan and A Balachandran A Software System for Locating Mobile Users Design Evaluation and Lessions Microsoft Technical Report Apr 2000 G Durgin
6. Nos 09 352 678 09 221 985 09 318 842 09 318 841 09 318 840 and other inventions cited previ ously are useful for designing measuring and optimizing communication networks because the products can predict radio frequency effects directly relevant to any communi cation network for any physical location That is using information about the physical layout of any communica tions network and the configuration of its hardware prior art can provide a visual display of the expected received signal strength intensity RSSI signal to noise ratio SNR rela tive received power intensity best server and equal power location as well as other useful parameters for voice and data networks for any modeled physical location These statistics can be predicted for the forward link from a transmitter to a receiver or for the reverse link replies from the original receiver to an original transmitter directions for wireless networks The site specific nature of these predic tions translates directly into quick and useful visualizations of the quality of a communication network However the prior art does not consider methods for properly modeling e g predicting the complexities that go into determining the values for actual network operating performance param eters that are simultaneously affected by multipath propa gation multiple interfering data transmissions from multiple sources signaling protocols equalization methods and the lik
7. PSEs for Wireless Communications Experiences with the S4W and SitePlan ner Projects Oct 28 2003 Skidmore et al Towards Integrated PSEs for Wireless Communications Experiences with the S4W and SitePlan ner Projects ACM Sigmobile Mobile Computing and Com munications Review vol 8 Issue 2 Apr 2004 pp 20 34 EDX Mircocell Indoor Module Apr 2000 p 1 63 Trademark Siteplanner 1999 p 1 NewHall W G Wideband Propagation Measurement Results Simulation Models and Processing Techniques for a Sliding Correlator Measurement System Dissertation p 1 159 Rappaport T S Last Mile Wireless Propagation Model ling Measurment amp Prediction HP 1998 p 1 20 EDX Signal Pro 1996 p 1 13 EDX Data File Format Specifications Jul 2001 p 1 24 Borst S et al Wireless Simulation and Self organizing Spectrum Management Bell Labs Technical Journal 1997 p 81 98 Cambridge Research Associates Synthetic Vision Sys tems 1999 p 1 31 Huang Y P Triangular Irregular Network Generation and Topographical Modeling 1989 Computers In Industry vol 12 No 3 p 203 213 Trademark Siteplanner 1999 registration No 2360957 published by United States Patent and Trademark Office p l Newhall W G Wideband Propagation Measurement Results Simulation Models and Processing Techniques for a Sliding Correlator Measurement System Master of Sci ence Dissertation Virgin
8. and changing settings or configurations of at least one com ponent of said wireless communications network based on instructions sent from said computer or server 2 The method of claim 1 wherein said site specific representation is three dimensional 3 The method of claim 1 wherein said data collection measurement collectors or agents are portable or fixed 4 The method of claim 1 further comprising the step of affixing said measurement collectors or agents permanently within said physical space 5 The method of claim 1 wherein said performance metric predicted in said predicting step is selected from the group consisting of throughput error rates packet latency packet jitter symbol jitter quality of service security cov erage area bandwidth bit error rate packet error rate frame error rate dropped packet rate queuing delay round trip time capacity signal level interference level bandwidth delay product handoff delay time signal to interface ratio signal to noise ratio physical equipment price and cost information 6 The method of claim 1 wherein said measurement data received in said receiving step obtained manually 7 The method of claim 1 wherein said measurement data received in said receiving step obtained autonomously 8 The method of claim 1 further comprising the step of storing said measurement data 9 The method of claim 1 further comprising the step of updating said computerized model 10 Th
9. and buffer sizes the data bandwidth in bits per second physi cal layer transmission methods including modulation tech niques such as QPSK or FHSS coding schemes such as CCK or trellis codes transport media such as copper fiber optic cable or wireless connections and specific frequency bands are taken into account by the invention These aspects are in addition to the consideration of the location and wireless specific criteria which includes transmitter re ceiver distance T R distance the propagation environment interference path loss number of users sharing the RF resources multipath delay the number of multipath com ponents and their strengths and angle of arrival the ratio of coherent to incoherent power and the RF bandwidth in Hz All of these variables may produce results which may be mapped into the form of equation 1 or 4 The predictions of the preferred form of the invention consider the characteristics of the data communications network users Information such as the type of data com munications traffic the users offer to the network the number of users and the usage patterns over time are stored in a location specific manner in the invention That is points can be placed which represent individual users and the traffic offered by that user or areas in which the characteristics of a group or pool of users can be assigned The invention takes these points and areas of user traffic into account when m
10. antenna gains noise level reflectivity surface rough ness path loss models attenuation factors throughput per formance metrics packet error rate round trip time dropped packet rate queuing delay signal level interference level quality of service bandwidth delay product handoff delay time signal loss data loss number of users serviced user 10 15 20 25 30 36 density locations of adequate coverage handoff locations or zones locations of adequate throughput E Iy system per formance parameters equipment price maintenance and cost information user class or subclass user type position location all in either absolute or relative terms 61 The system or apparatus of claim 56 further compris ing a storage device for storing said measurement data 62 The system or apparatus of claim 56 wherein said computerized model is stored on at least one server which may be the same or different from said computer or server 63 The system or apparatus of claim 62 wherein said computerized model is stored on a plurality of servers wherein said plurality of servers can communicate with each other 64 The system or apparatus of claim 63 wherein said plurality of servers have a heirarchical relationship to one another 65 The system or apparatus of claim 62 further compris ing at least one portable client device that can communicate with said at least one server 66 The system or apparatus of claim 64 wherein
11. are somewhat useful for diag nostic and troubleshooting work on data networks Examples of these command line programs include ping and traceroute Using the ping command line program it is possible to measure approximate data latency between dif ferent data network devices and confirm that a network connection is available between the two devices Network connections often consist of individual devices relaying network packets from the transmitter to the receiver This means a network connection can consist of several actual transmissions between the original transmitter and the intended receiver Each individual relay is called a link Typically a full network connection consists of several links Thus using traceroute a probable path from relaying device to relaying device between the transmitter and the receiver can be determined so that the exact links used by the network transmissions are known Additionally using trac 10 15 20 25 30 35 40 45 50 55 60 65 6 eroute the time required to traverse each individual link can be measured and individual links that may not be function ing properly can be identified Various command line tools that are not included with operating systems have also been developed for somewhat more accurate though still approximate network measure ment tasks Some examples of these tools include ttcp and tcpdump ttcp stands for Test TCP http www pcausa com Utilities
12. bottleneck a particular component or device which has a maximum rating of Tmax bits per second This component bounds the maximum possible throughput of the network Consider that capacity represents the capacity or throughput of a device or network defined as T or Capac ity where T x y z t Tmax y where y is a scaling factor that fuses many different complicated physical electrical and logical conditions into a simple value that ranges between 0 and 1 When gamma is 0 there is no capacity 10 15 20 25 30 35 40 45 50 55 60 65 28 When gamma is 1 there is maximum capacity Note that T is a function of 3 D positioning in the network as well as a function of time For a particular user the goal of a network predictive model is to predict the capacity as a function of 3 D position and as a function of time Thus T x y z t will range between 0 and Tnax The load put on to a data communications network impacts the capacity of an individual user The number of users and the usage patterns of each user affect the capacity of each user in a data communications network The pre ferred embodiment of the invention allows a network designer to see the effects of network loading on the impor tant network statistics by measuring the instantaneous traf fic conditions with the measurement agents as described above It is possible to determine in situ capacity measure ments through other means such as obse
13. claims to offer should be compared to the actual bandwidth for different requested bandwidths FIG 3 illustrates the difference between bits packets and frames Various error rates are defined for data communi cation networks for bits packets and frames Bits are the core of packets and frames The bits are the actual message data that is sent on the communications network Packets include the data bits and the packet header and packet footer The packet header and packet footer are added by commu nications network protocols and are used to ensure the data bits are sent to the right location in the communications network and interpreted correctly by the receiver The packet header and packet footer are also used to ensure that packets are sent correctly and that errors are detected should they occur Frames are simply series of bits with a certain pattern or format that allows a receiver to know when one frame begins or ends A bit error rate is the percentage of bits that reach the receiver incorrectly or do not reach the receiver as compared to the number of bits sent Packet error rate or dropped packet rate is the percentage of packets that reach the receiver incorrectly or do not reach the receiver as compared to the number of packets sent A frame error rate is the percentage of frames that reach the receiver incorrectly or do not reach the receiver as compared to the number of packets sent Several terms are used to quantify the delay
14. communication network performance The research described below represent the work which pertains to the field of this invention Xylomenos and Polyzos have explored the performance of UDP and TCP packets sent over several fixed IEEE 802 11 wireless LAN network connections in Xylomenos G Polyzos G C TCP and UDP Performance over a Wireless LAN Proceedings of IEEE INFOCOM 1999 The research has focused on throughput limitations caused by software implementation issues and operating system short comings The researchers used their own modified version of the command line utilities ttcp tcpdump and nstat under Linux to perform UDP and TCP throughput tests All mea surements were taken between three fixed locations and focused on varying the wireless LAN card types PCMCIA or ISA and the end user computer hardware i e Pentium 150 with 48 MB of RAM vs a Pentium 200 MMX with 64 MB of RAM The conclusions the researchers make are recommendations for changes in the implementation of 10 15 20 25 30 35 40 45 50 55 60 65 8 network protocols and linux operating system enhance ments The measurements did not consider the effects of different physical locations or the effect of variations in the wireless communications channel on the network through put Maeda Takaya and Kuwabara have published a measure ment of wireless LAN performance and the validity of a Ray tracing technique to predict the per
15. components radio frequency band width protocol coding scheme and 3 D location In order to predict the bandwidth and throughput of a network connection the appropriate functions and constants may be calculated from the listed parameters and then predicted for each location and time desired For a wired network throughput T or bandwidth BW may be derived from a vendor s specification sheet of a product or device or may be measured in a special labora tory setting Alternatively T or BW may be calculated through analysis or simulation or may be measured in the field using a number of known devices These means may be used to determine the proper value for T or BW in a network prediction enging such as contemplated here A formula for predicting the throughput and bandwidth for a wireless data communications channel is shown in equation 1 T or BW Ci Ad B amp C a M C D RSSI E RSSI F Cay G P Kj izl where T is throughput BW is bandwidth d is the distance between a transmitter and a receiver RSSI is the received signal strength intensity which is the power level of the signal at the receiver either in absolute values or in loga rithmic values A B C C C3 C4 D E F K are constants or may represent linear or nonlinear functions of one or more physical or electrical parameters such as physical environ ment type packet size modulation modem type or other parameters that relate the phy
16. in a situation where the transmitter and receiver are the same computer no hardware is actually involved in the transmis sion By measuring network statistics in this situation one can quantify the performance of just the computer software By comparing the situation where the transmitter and send are the same to a situation where the transmitter and receiver are different computers the performance of just the computer hardware can be identified Since the performance of the software in either case will be quite similar the performance of just the hardware in a connection between two computers can be extrapolated by assuming the software will perform similarly in either case Extrapolating the performance of individual network components from measured performance metrics can be time consuming For this reason the preferred embodiment of the invention is able to read in data results from a plethora of measurement tools system utilities and network logfiles to a single internal format The invention is capable of reading in the output of command line utilities such as ping or ttcp the logfiles generated by routers and switches such as tcpdump or even the logfiles of other commercial mea surement programs and these measurement results are US 6 973 622 B1 19 stored for use in the predictive engine The combination of these imported files to a single internal format allows the invention to combine many different measurements and activi
17. location with the 3 D environment is based on the first best guess predictive models As explained subse quently these initial best guess or blind models may be based on simulation analysis or some combination thereof The empirically based predictive models and the initial best guess predictive models may be used in subsequent envi ronments different from the environment for which mea surements or best guesses were made and the invention allows a catalogue of models to be used easily by the user for subsequent network prediction or design Measurements of actual network performance may then be overlaid and displayed and stored simultaneously with the network pre diction parameters for rapid comparison Furthermore opti mization routines compute the best values for minimum error for new predictive models that match the measured network performance within the environment Thus the US 6 973 622 B1 I7 invention allows the user to relate empirically derived pre dicted performance parameters or initially guessed network performance parameters within a 3 D site specific configu ration of the actual installed or contemplated network using specific information and physical locations about the net work devices and by using the models for wired networks and wireless propagation multipath and noise The model techniques for this invention fuse the many factors that impact network performance into simpler models that sup port
18. network performance optimization using ion and measurement Measure site specific data communications network for desired performance criteia Predict network performance using measurement data for accurate calculations In model adjust settings of hardware location or network devices or equipment to improve performance new network Re generate performance predictions Compare predictions to performance goals Yas Change Performance No goals achieved hardware or software senings add additional hardware and change location of equipment as decided in above predictions Measure site specific data communications network for desired performance criteria Data communication network optimized to meet specific performance criteria US 6 973 622 B1 Page 2 5 710 758 5 755 072 5 761 093 5 774 669 5 794 128 5 799 154 5 802 146 5 809 282 5 815 395 5 821 937 5 825 759 5 828 960 5 831 610 5 832 389 5 845 124 5 861 887 5 867 112 5 877 777 5 878 328 5 907 850 5 917 808 5 923 850 5 926 762 5 940 196 5 945 976 5 948 055 5 949 335 5 949 988 5 953 669 5 963 867 5 970 406 5 977 851 5 987 328 5 994 984 6 006 021 6 018 625 6 021 316 6 032 105 6 038 547 6 044 273 6 058 102 6 058 262 6 059 842 6 061 722 6 075 541 6 085 335 6 088 522 6 104 699 6 108 309 6 111 857 6 122 083 6 148 010 6 199 032 6 204 813 6 208 833 6 229 540 6 243 772
19. of the amount of data which can be transmitted between two locations in a data network not including header footer or routing information bits It is generally measured in bits per second bps and can be specified for hardware software firmware or any com bination thereof that make up a connection between trans mitter and receiver in a data communication network Band width is similar to throughput as it is defined for data communication networks Bandwidth is the raw data rate that may be sustained by a given communications network and is generally slightly higher than throughput For instance an Ethernet link may be rated for a 10 Mbps bandwidth but a measurement of an actual file transfer may show that the rate at which data can actually be transferred between two computers using that same link is only a throughput of 6 8 Mbps as is taught in Peterson L L and Davie B S Computer Networks A Systems Approach San Francisco Morgan Kaufmann Publishers 2000 Quality of service QoS is a term that is used to describe networks that allocate a certain amount of bandwidth to a particular network transmitter Such a network will allow a transmission to request a certain bandwidth The network will then decide if it can guarantee that bandwidth or not The result is that network programs have a reliable band width that can more easily be adapted to When the quality of service of a connection is measured the bandwidth that the network
20. pcattcp htm and is a free utility originally written for the BSD Linux operating system but is now available for other UNIX operating systems as well as Microsoft Win dows ttcp is a basic point to point throughput measurement program that allows the user to control buffer sizes various low level TCP or UDP options and control the exact data that is sent tcpdump is a simple utility from the class of tools called packet sniffers Packet sniffers allow a network administra tor to view the content including header and footer infor mation of actual packets on a network tcpdump allows a user to view or sniff packets that are received by a host though not necessarily intended for that host and display all headers that match a certain user configurable pattern tcpdump is a useful tool for troubleshooting network con nections because it allows the user a direct view of the exact network traffic Pathchar is a UNIX command line utility which is capable of measuring the throughput between each network relay device e g a router hub or switch in a data communica tions network by varying the size of the test packets that it transmits and measuring the latency of that packet transmis sion to various network points The tool functions very similarly to traceroute but adds the ability to measure throughput albeit indirectly not just latency Pathchar is only limited by the network hardware in the links it mea sures The program needs a
21. prediction and comparison of measured versus pre dicted network performance for radio wireless and wired networks Thus performance prediction can be ascertained and compared to measured network performance for use in ongoing network deployment Furthermore by comparing measured network perfor mance metrics to predicted metrics the invention allows new field measurements to update the previous prediction models in a convenient method which provides a catalogue of models that is stored and displayed to the user either locally or remotely Alternatively using the hierarchy of servers it is possible to use remotely located servers which compute transmit or receive such measurements and pre dictive models for the remote use display measurement and storage of model parameters and results This is particularly convenient for network administrators who wish to monitor the performance and design of networks that are physically distant from the network of interest Measurements of a particular device for desired perfor mance criteria is accomplished either by using the measure ment software module available in the preferred invention or by importing a log file from another software or hardware measurement tool The measurement module within the preferred invention allows the measurement of the perfor mance of any specific portion of a communications network using two or more software programs which are installed and run on either sides of a
22. said system includes a plurality of portable client devices 67 The system or apparatus of claim 56 further compris ing a storage medium or display for respectively storing or visualizing data representing comparisons of measurements with predictions 68 The system or apparatus of claim 56 further compris ing a storage medium or display for respectively storing or visualizing either or both logical connections of network components or physical locations of network components UNITED STATES PATENT AND TRADEMARK OFFICE CERTIFICATE OF CORRECTION PATENT NO 6 973 622 Bl Page 1 of 1 APPLICATION NO 09 668145 DATED December 6 2005 INVENTOR S Rappaport et al It is certified that error appears in the above identified patent and that said Letters Patent is hereby corrected as shown below Column 30 line 7 change each of to of Column 30 line 38 change interface to interference Column 30 line 42 insert is after step Column 30 line 44 insert is after step Column 32 line 2 change interface to interference Column 32 line 21 insert or apparatus after system Column 32 line 48 delete a Column 33 lines 36 37 delete one or more performance metrics are selected from Column 35 line 14 delete one or more performance metrics are selected from Signed and Sealed this Fifth day of September 2006 am WE ae JON W DUDAS Director of the Uni
23. the results in the physically accurate three dimensional model of a data communications network and the environ ment in which it is installed Further the invention can display the measured and predicted performance criteria for any data communications network in the three dimensions site specific model of the environment These capabilities provide a powerful design environment for wired and wire less networks which allows one skilled in the art to quickly and easily design measure predict optimize and visualize data network communication performance criteria in a three dimensional site specific manner using methods never before contemplated BRIEF DESCRIPTION OF THE FIGURES FIG 1 Example transmission of data over a communi cations network FIG 2 Creation of a digital signal from an analog signal FIG 3 Illustration of the difference between bits packets and frames FIG 4 Illustration of the data displayed in each node of the Tree View of a data communications network 10 15 20 25 30 35 40 45 50 55 60 65 12 FIG 5 Method for creating a 3 D site specific model of the environment FIG 6 Method for optimizing a data communications network using predictions FIG 7 Method for optimizing a data communications network using measurements FIG 8 Method for optimizing a data communications network using predictions and measurements DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
24. to forming a prediction model of network performance These first guess values may then be iterated by the invention based on feedback from the site specific measurements of the actual network A measured set of data for a typical operating environ ment with multiple transmitters in a wireless or wired network are recorded stored and displayed by the inven tion as taught in the previous description about the mea surement agents and server processors Then some form of best fit algorithm minimum mean square median filter etc may be applied to the predictive models provided in the equations taught below to provide a table look up for determining proper performance values e g proper values for constants or functions in the performance parameter equations listed below for a particular site specific network design This table look up method allows measured data to be translated into values that may then be used to drive predicted data for all subsequent predictions conducted within the same site specific 3 D environment in which measurements were made Alternatively best guess perfor mance metric values or best guesses for the functions or constants in the equations listed below may be fed into the invention either manually or automatically through a stor age means or via a wireless or wired means from a remote or collocated location for a specific 3 D modeled network environment wherein the predicted performance at any space or
25. types oper ating systems and protocols available today The program uses a server and several small agent programs to collect data The server checks each agent installed on user s computers throughout the network at regular intervals and uses them to measure network characteristics while storing US 6 973 622 B1 7 the results on the server These agents can measure the network connection to the server or to one another and are capable of simulating the traffic patterns of any network program and any desired usage pattern of one or more hypothetical users The program is also capable of using the measured data to forecast expected network traffic and conditions Visonael Corporation was NetSuite Development Cor poration makes several network tracking and measurement products including NetSuite Audit Design and Advisor These software products are capable of automatically detect ing the network equipment in use This information as well as manually entered information can then be placed in a physical or logical diagram of the network Visonael also offers a product to verify that networks have been configured properly and can make recommendations for configuration changes and upgrades to your network The software prod ucts are unable to predict or measure the performance in a site specific manner and are not capable of predicting the performance of wireless based data communication net works SAFCO Technologies Inc now a par
26. upon the one or more performance metrics for said wireless communications network 84 The system or apparatus of claim 81 wherein the at least one component that participates in communicating information over the wireless communications network hav ing settings or configurations changed based on said instructions comprises network equipment and wherein the instructions are provided from the computer or server to the network equipment based upon the one or more performance metrics for said wireless communications network to thereby improve the performance of the wireless communications network 85 The system or apparatus of claim 81 wherein said instructions are transmitted from said computer or server to said at least one component that participates in communi cating information over the wireless communications net work using an SNMP protocol communication 86 The system or apparatus of claim 81 wherein the instructions are provided based upon the one or more per formance metrics for said wireless communications network to thereby improve the performance of the network 87 The system or apparatus of claim 81 wherein the at least one component that participates in communicating information over the wireless communications network com prises network equipment 88 The system or apparatus of claim 87 wherein said site specific representation is three dimensional 10 15 20 25 30 35 40 45 50 55 65 4 8
27. whereby a mobile receiver is operated and network performance parameters are measured within the site specific environment it is then possible to determine best fits for particular modem manufacturers applying con cepts described in equation 1 Bandwidth delay products can be calculated by the inven tion directly using information about any or all of the environment three dimensional position protocol type multipath delay packet sizes radio frequency radio fre quency bandwidth coding number strength and angle of arrival of multipath components signal strength transmis sion propagation processing and queuing delay bit error rate packet error rate and frame error rates Alternatively the invention can calculate the bandwidth delay product indirectly using previously predicted values A bandwidth delay product is calculated by multiplying the bandwidth of a certain network device by the total delay introduced by that device Thus the formula is illustrated here in equation 5 BW 5 BWD net Where BWD is the bandwidth delay product BW is the bandwidth and T is the total delay introduced The invention uses statistical models of the consistency of data communications network hardware to predict packet jitter and quality of service QoS Both of these perfor mance criterions are measures of the reliability of a network to provide consistent data arrival times Thus to calculate the QoS or jitter of a connecti
28. 0 35 40 45 50 55 60 65 16 server that receives measurement data from measurement agents it is possible to remotely monitor and then predict the performance of a network that is physically very far from the particular server processor The measurement agents may be further controlled or configured by the server processor so that the agents may be tuned or instructed to perform different types of measure ments such as different packet transmission rates observa tion intervals averaging intervals protocol types or other sensible changes which those skilled in the are would conceive for proper network optimization A second method for predicting the performance of net work parameters is through the use of analytical or simula tion methods These analytical and simulation methods are well known and relate the physical and electrical charac teristics of the network channel to the physical and electrical characteristics of the various network components Through simulation or analysis it is possible to determine approxi mations or bounds on the typical values that one would expect in an actual network configuration of specific com ponents The present embodiment of the invention allows a user to enter the results of such calculations so that they are applied as inputs to the prediction model Therefore a user of the invention may simply enter blind values based on known methods as a first guess approach
29. 01 G06F 19 00 2006 01 G06F 15 16 2006 01 S2 U S CL cete 715 735 715 736 703 21 703 22 709 211 58 Field of Classification Search None See application file for complete search history 45 Certificate Issued Feb 2 2010 5 608 854 A 3 1997 Labedz et al 5 627 879 A 5 1997 Russell et al 5 644 623 A 7 1997 Gulledge 5 689 705 A 11 1997 Fino et al 5 710 758 A 1 1998 Soliman et al 5 726 979 A 3 1998 Henderson et al 5 761 674 A 6 1998 Ito 5 859 839 A 1 1999 Ahlenius et al 5 907 494 A 5 1999 Dangelo et al 5 920 607 A 7 1999 Berg 5 953 669 A 9 1999 Stratis et al 5 956 028 A 9 1999 Matsui et al Continued FOREIGN PATENT DOCUMENTS WO 0013115 3 2000 OTHER PUBLICATIONS Skidmore SMT Plus 1 0 user s manual Aug 1996 Zhang Formulation of multiple diffraction by trees and buildings for radio propagation predictions for local multi point distribution service J Res Natl Inst Stand Tech nol 1999 Fellner D Radio wave propagation Carpet Computer Graphics Dept of Computer Science 1998 Rappaport et al The future of wireless communications MPRG 1999 Ulffe et al Measuring the 2 4 GHz Band for indoor wire less communications Wireless design laboratory 2000 Continued Primary Examiner Woo H Choi ABSTRACT 56 References Cited 57 U S PATENT DOCUMENTS 4 817 012 A 3 1989 Cali 4 964 060 A 10 1990 Hartsog 5 091 869 A 2 199
30. 2 Ingram et al 5 425 076 A 6 1995 Knippelmier 5 463 464 A 10 1995 Ladewski 5 465 153 A 11 1995 Ladewski 5 515 269 A 5 1996 Willis et al 5 517 575 A 5 1996 Ladewski A system and method for design tracking measurement prediction and optimization of data communications net works includes a site specific model of the physical environment and performs a wide variety of different calcu lations for predicting network performance using a combina tion of prediction modes and measurement data based on the components used in the communications networks the physical environment and radio propagation characteristics Method for optimizing a data communications network using predictions and ments Data communications network prediction and performance optimization using measurement Measure site specific data communications network for desired performance criteria Predict network performance using measurement data for accurate calculations In model adjust settings of network devices or hardware location or add new network US 6 973 622 C1 Page 2 5 982 330 5 984 511 5 986 670 6 002 941 6 012 152 6 014 565 6 084 168 6 091 362 6 112 088 6 119 009 6 119 010 H1896 6 151 310 6 162 488 6 236 409 6 256 506 6 259 924 6 266 615 6 272 447 6 283 759 6 295 535 6 308 072 6 317 599 6 331 836 6 345 239 6 385 454 6 424 264 6 442 507 6 459 435 6 466 938 6 487 414 6 493 67
31. 2003 Rappaport et al 12 2003 Rappaport et al 12 2003 Aljadeff et al 1 2004 Trikkonen et al 1 2004 del Prado et al 2 2004 Rappaport et al 4 2004 Myllymaki et al 4 2004 Bemas et al 5 2004 da Costa et al 7 2004 Rappaport et al 7 2004 Rappaport et al 8 2004 Rappaport et al 9 2004 Rappaport et al 9 2004 Rappaport et al 10 2004 Sindhushayana et al 10 2004 Shur et al 12 2004 Rappaport et al 12 2004 Rappaport et al 6 2005 Rappaport et al 11 2005 Feisst et al 12 2005 Rappaport et al 1 2006 Rappaport et al 1 2006 Rappaport et al 2 2006 Skidmore et al 6 2006 Rappaport et al 5 2007 Rappaport et al 5 2007 Rappaport et al OTHER PUBLICATIONS Hashemi H The indoor radio propagation channel IEEE vol 81 No 7 Jul 1993 Liu et al Modelling microcellular radio wave propaga tion IEEE May 1996 Fellner et al MRT A tool for simulations in 3D geomet ric domains ESM 1997 Stamm et al A prototype system for light propagation in terrains IEEE 1998 EAC 50 Repeater System for In Building Coverage Installation and Operation Manual Allen Telecom Com pany 2000 Referred to as EAC 50 Rappaport T et al Site Planner 3 0 User s Manual Wireless Valley Communications Inc 1998 Bertoni H et al UHF Propagation Prediction for Wireless Personal Communications Proceeding of IEEE vol 82 No 9 Sep 1994 pp 1333 1359 Honcharenko W et al Mechanisms Govern
32. 9 6 499 006 6 509 906 6 625 454 6 675 328 6 681 140 6 690 652 6 721 769 6 754 488 6 772 103 6 785 547 6 791 571 6 795 858 6 804 578 6 850 946 6 876 951 6 901 051 6 931 364 6 947 708 6 971 063 7 019 753 7 023 356 7 035 642 7 054 643 7 055 107 7 085 697 7 096 034 7 096 160 7 096 173 7 124 101 7 155 228 7 162 507 7 164 883 7 171 208 7 235 766 7 243 054 7 246 045 7 286 971 7 295 119 U S PATENT DOCUMENTS POBHUBpBpB RPB R R RP 11 1999 11 1999 11 1999 12 1999 1 2000 1 2000 7 2000 7 2000 8 2000 9 2000 9 2000 10 2000 11 2000 12 2000 5 2001 7 2001 7 2001 7 2001 8 2001 9 2001 9 2001 10 2001 11 2001 12 2001 2 2002 5 2002 7 2002 8 2002 10 2002 10 2002 11 2002 12 2002 12 2002 1 2003 9 2003 1 2004 1 2004 2 2004 4 2004 6 2004 8 2004 8 2004 9 2004 9 2004 10 2004 2 2005 4 2005 5 2005 8 2005 9 2005 11 2005 3 2006 4 2006 4 2006 5 2006 5 2006 8 2006 8 2006 8 2006 8 2006 10 2006 12 2006 1 2007 1 2007 1 2007 6 2007 7 2007 7 2007 10 2007 11 2007 Koyanagi et al Vasey Glandon et al Dries et al Ablay et al Douik et al Bonta Sitrick Stilp et al Haartsen Baranger et al Labedz Hoffpauir et al Dent Gevelber et al Hartman Alexander Jr et al Alexander Jr et al Jin Gavin et al Price et al Radcliffe et al Labedz et al Rappaport et al Jandrell Bowman Amuah Bahl et al Giraldin et al Skidmore et al Eichel Goldberg Tanay et al Ra
33. 9 A system or apparatus for analyzing and adjusting a wireless communications network comprising a computer or server for generating or using a computer ized model of a wireless communications network that is in a three dimensional space said computerized model providing a site specific representation of one or more of a floor plan building layout terrain characteristics or RF characteristics said computer ized model identifving locations within said three dimensional space of one or more components that par ticipate in communicating information over said wireless communications network said computerized model having modeled attributes that are measured predicted or calculated for at least one of said one or more components one or more measurement collectors or agents operating or operational within said three dimensional space which send measurement data to said computer or server said computer or server predicting one or more performance metrics for said wireless communications network based on said measurement data and said modeled attributes for said at least one of said one or more components and said computer or server can send instructions to one or more components that par ticipate in communicating information over said wire less communications network which cause settings or configurations of at least one component to be changed 90 The system or apparatus of claim 89 wherein the instructions are sent from said compu
34. G TR 97 13 Jun 1997 Master s Thesis unpublished by Virginia Tech for 2 years after submission R Skidmore et al Russell Senate Office Building Propaga tion Study Project Report for Joseph R Loring amp Associ ates Project Update AoC Contract Acbr96088 prepared for Office of the Architect of Capital Jan 19 1997 R Skidmore et al Russell Senate Office Building Propaga tion Study Project Report for Joseph R Loring amp Associ ates Assessment and Study of the Proposed Enhancements of the Wireless Communications Enviroment of the Russell Senate Office Building RSOB and Associated Utllity Tun nels AoC Contract Acbr96088 prepared for Office of the Architect of the Capitol Feb 20 1997 R Torres et al CINDOOR An Engineering Tool for Planning and Design of Wireless Systems in Enclosed Spaces IEEE Antennas and Propagation Magazine vol 41 No 4 Aug 1999 R Skidmore et al Interactive Coverage Region and System Design Simulation for Wireless Communication Systems in Multi Floored Indoor Enviroments SMT Plus tm IEEE ICUPC Proceedings 1996 T S Rappaport et al Radio Propagation Prediction Techniques and Computer Aided CHannel Modeling for Embedded Wireless Microsystems MPRG Tech Report MPRG TR 95 08 Virginia Tech Jul 1995 Company Web Page Actix www actix com product name E NOS now E AMS no date given Company Web Page Agilent www agilent com produc
35. OF THE INVENTION The present invention contemplates the abilities to design measure predict and optimize the performance of a data communication networks The invention uses an accurate computer generated three dimensional model of a commu nications network stored in a computer database environ ment The invention allows the user to place the network cables hubs routers switches bridges wireless access points amplifiers splitters antennas point omnidirec tional directional leaky feeder distributed array etc transceivers terminators and other communications and computer networking equipment in their actual modeled physical locations The present invention uses this highly accurate model of the physical layout of infrastructure to allow a user to visualize predict and optimize the perfor mance of any communication network in any 3 D site specifically modeled physical location The present embodiment of the invention is capable of modeling the site specific communications network hard ware from both a logical connection and a physical location perspective The invention uses well known hierarchical logical connection concepts sometimes called topological layout suited for data communications networks in combi nation with a physically accurate site specific model of the data communications network Previous inventions focus on only the topological or relational layout of network com ponents with one another This inv
36. T S Rappaport H Xu Measurements and Models for Radio Path Loss and Penetration Loss in and Around Homes and Trees at 5 85 GHz IEEE Transactions on Communications vol 46 No 11 Nov 1998 C M Peter Ho et al Antenna Effects on Indoor Obstructed Wireless Channels and a Deterministic Image Based Wide Band Propagation Model for In Building Personal Com munications Systems International Journal of Wireless Information Networks vol 1 No 1 1994 S Kim et al Radio Propagation Measurements and Predic tions Using Three dimensional Ray Tracing in Urban Enviroments at 908 MHZ and 1 9 GHz IEEE Transactions on Vehicular Technology vol 48 No 3 May 1999 T S Rappaport et al Use of Topographic Maps with Building Information to Determine Antenna Placements and GPS Satellite Coverage for Radio Detection and Tracking in Urban Environments MPRG Technical Reports MPRG TR 95 14 Virginia Tech Sep 1995 R K Morrow Jr and T S Rappaport Getting In Wireless Review Magazine Mar 2000 Wireless Valley Communications Inc SitePlanner 3 16 for Windows 95 98 NT User s Manual Software User s Manual pp 5 148 to 5 156 1999 M Panjwani et al Interactive Computation of Coverage Regions for Wireless Communication in Multifloored Indoor Environments IEEE Journal on Selected Areas in Communications vol 14 No 3 Apr 1996 L Piazzi and H L Bertoni Achievable Acurracy of Site Specific Path Los
37. US006973622B1 a United States Patent Rappaport et al 10 Patent No US 6 973 622 B1 54 SYSTEM AND METHOD FOR DESIGN TRACKING MEASUREMENT PREDICTION AND OPTIMIZATION OF DATA COMMUNICATION NETWORKS 75 Inventors Theodore Rappaport Salem VA US Roger Skidmore Blacksburg VA US Benjamin Henty Blacksburg VA US 73 Assignee Wireless Valley Communications Inc Austin TX US Notice Subject to any disclaimer the term of this patent is extended or adjusted under 35 U S C 154 b by 724 days 21 Appl No 09 668 145 22 Filed Sep 25 2000 51 Int Cl sss G06F 3 00 GO6F 19 00 GOOF 15 16 52 USS Clena 715 735 715 736 703 21 703 22 709 221 58 Field of Search 703 2 3 5 21 703 22 455 33 1 33 4 564 446 345 133 202 186 715 735 736 734 709 221 222 56 References Cited U S PATENT DOCUMENTS 4 675 147 A 6 1987 Schaefer et al 4 736 453 A 4 1988 Schloemer 4 885 694 A 12 1989 Pray et al 5 111 392 A 5 1992 Malin 5 119 307 A 6 1992 Blaha et al 5 239 487 A 8 1993 Horejsi et al 5 293 640 A 3 1994 Gunmar et al 5 307 261 A 4 1994 Maki et al 5 337 149 A 8 1994 Kozah et al 5 339 184 A 8 1994 Tang 5 375 123 A 12 1994 Andersson et al 5 394 522 A 2 1995 Sanchez Frank et al 5 450 615 A 9 1995 Fortune et al 5 458 123 A 10 1995 Unger 5 465 390 A 11 1995 Cohen 45 Date of Patent Dec 6 2005 5 467 441 A 11 1995 Stone et al 5 482 050 A 1 1996 Smo
38. aking predictions of network performance criterions This means that if large numbers of users are found in an area covered by access points that are able to adapt to heavy usage the invention is able to accurately predict the perfor mance of these or any other conditions This is only possible because of the accurate location specific model of the data communication network Additionally since the preferred form of the invention tracks usage patterns of users over time the resulting measurements may be used by a server processor to form table look up values for the con stants or functions of Equations 1 or 4 Different values of constants or functions for Equations 1 or 4 may be found to predict the performance of the network at different times of day This is an important aspect of a data commu nication network prediction model because real networks have peak usage times and lulls in which usage is lower By tracking the usage of a data communications network over time the preferred form of the invention can determine if the network will have difficulties at certain times In communications network the capacity is always a scaled version of the theoretical maximum possible capacity and the impact of various users and their propagation characteristics message sizes as well as the network char acteristics all combine to bound or limit the capacity that an individual user sees on a network Consider a network that has as a
39. ance metrics for said wireless communications network based on said measurement data and said parameters of opera tion for said at least one of said one or more compo nents and changing setting or configurations of at least one compo nent that participates in communicating information over said wireless communications network based on instructions sent from said computer or server 98 The method of claim 97 wherein the instructions are sent from said computer or server to said at least one com ponent that participates in communicating information over the wireless communications network to update relevant set tings of the at least one component based upon the predic tions 99 The method of claim 97 wherein the instructions are based upon the one or more performance metrics for said wireless communications network 100 The method of claim 97 wherein the at least one component that participates in communicating information over the wireless communications network having settings 20 25 30 40 45 50 55 60 65 6 or configurations changed based on said instructions com prises network equipment and wherein the instructions are provided from the computer or server to the network equip ment based upon the one or more performance metrics for said wireless communications network to thereby improve the performance of the wireless communications network 101 A site specific method for analyzing and adjusting a co
40. applied to a network device Alterna tively processing delay may be the time required for a source to produce a meaningful data stream once it is instructed to do so Processing delay is known to be zero for devices that do not perform any processing such as passive network components like cables antennas or splitters Pro cessing time may depend on the packet size protocol type operating system vendor firmware hardware and software versions or configurations and the type of device and the current computing load on the device To predict the pro cessing delay of any device it is necessary use a model that accounts for all of these effects These models may be measured in the field measured in a test facility obtained from vendors or derived from analysis or simulation Queuing delay is only applicable to devices that transmit data from multiple users or multiple connections The queu ing delay of a device is the amount of time a particular packet must wait for other traffic to be transmitted It is difficult to predict the queuing delay of a particular connec tion because it depends on the amount of traffic handled by a particular device For this reason queuing delays can be predicted using a statistical random variable based on the expected performance of the device and or the expected traffic load Alternatively average median best or worst case or some other linear or nonlinear weighting of queuing delay times as defined b
41. ast transmission and for each individual trans mitter and receiver is quite powerful This ability allows network designers to better choose which transmitters of multicasts might be redundant or which broadcast transmis sions are insufficient to reach all the desired receivers In some data communications network the performance of specific pieces of equipment such as Ethernet Bridges or even a single cable is hard to measure because it is transparent to the network layer of a data communications network For this reason the ability of the invention to determine the performance of a single device through extrapolation is quite useful The preferred embodiment of the invention is able to use known performance data for specific pieces of network equipment and extrapolate the contribution of other devices in the network Measuring and extrapolating enough individual hardware and software links can identify the performance of all network devices The accuracy and reliability of this procedure heavily depends on an accurate and site specific model of the data communications network which the invention possesses Extending the extrapolation concept of performance evaluation to the software and hardware components of network equipment demonstrates a further capability of the preferred embodiment of the invention The invention is able to distinguish in some cases between the performance limits due to software and those due to hardware For example
42. ations network having settings or configurations changed based on said instructions com prises network equipment and wherein the instructions are provided from the computer or server to the network equip ment based upon the one or more predicted performance metrics for said wireless communications network to thereby improve the performance of the wireless communications network 97 A method for analyzing and adjusting a wireless com munications network comprising the steps of generating or using with a computer or server a computer based representation of a wireless communi cations network within a three dimensional space in which said communications network is deployed said computer based representation providing a site specific representation of one or more of a floor plan building model terrain characteristics or RF characteristics said computer based representation identifying loca tions within said physical space of one or more compo nents that participate in communicating information over said wireless communications network said computer based representation having parameters of operation that are measured predicted or calculated for at least one of said one or more components downloading or inputting files of measurement data to said computer or server where said measurement data is obtained from said three dimensional space or from said wireless communications network predicting or providing one or more perform
43. cation Ser No 09 318 842 entitled Method and System for Managing a Real Time Bill of Materials filed by T S Rappaport and R R Skidmore now U S Pat No 6 493 679 Ser No 09 318 841 entitled Method And System for a Building Database Manipulator filed by T S Rappaport and R R Skidmore now USS Pat No 6 850 946 Ser No 09 318 840 entitled Method and System For Automated Optimization of Com munication component Position in 3D filed by T S Rap paport and R R Skidmore now U S Pat No 6 317 599 Pending application entitled Method and System for Designing or Deploying a Communications Network which Allows Simultaneous Selection of Multiple Components filed by T S Rappaport and R R Skidmore Ser No 09 633 122 filed on Aug 4 2000 as well applications entitled Method and System for Designing or Deploying a Communications Network which Considers Frequency Dependent Effects Ser No 09 632 121 filed by T S Rappaport and R R Skidmore on Aug 4 2000 now U S Pat No 6 625 454 as pending application entitled Method and System for Designing or Deploying a Communications Network which Considers Component Attributes Ser No 09 632 853 filed by T S Rappaport R R Skidmore and Eric Reifsnider on Aug 4 2000 as well as application entitled Improved Method and System for a Building Database Manipulator Ser No 09 633 120 filed by T S Rappaport and R R Skidmore n
44. complicated network parameters using a priori measurements from an existing network or by using the site specific layout details of particular components within a data communications net work Furthermore none of the prior art has autonomously measured site specific network performance parameters from an actual network system or subsystem using a system of agents and then applying the specific 3 D locations and measured results of those measurement agents to create a 3 D prediction model for future network performance in the same similar or different physical environments Further more none of the prior art has developed a hierarchical system of measurement and prediction engines that have the ability to measure network performance parameters in the field and have the ability to produce a predictive engine for network performance parameters that can be shared with remote prediction engines for the purpose of measuring and predicting network performance in a 3 D site specific man ner The present invention extends the prior art in a non obvious way to provide wireless and wired network perfor mance prediction visualization and measurement for impor tant data communications specific performance criteria also called performance parameters such as throughput band width quality of service bit error rate packet error rate frame error rate dropped packet rate packet latency round trip time propagation delay transmission delay p
45. construct the information using some predetermined method For example the numbers could represent digital samples of the 10 15 20 25 30 35 40 45 50 55 60 65 2 signal voltage that should be applied to a speaker so that the speaker reproduces the sound of the voice as shown in FIG 1 The information is in this case the voice message which was transmitted over the communications network The process of representing information can be analog or digital In an analog communications network the message that is transmitted is a continuously changing number In a digital network numbers that change at discrete regular intervals instead of continuously represents the message The signal is represented by a single number each interval This number may be converted to a binary form so that the entire message can be represented as a finite number of ones and zeros Each binary digit in the message is called a bit These bits are transmitted and interpreted by the receiver as the message Binary and digital versions of a signal are shown in FIG 2 Data communication networks are a specific type of communication network that transmit digital information represented as bits or bytes a group of 8 bits in an indoor or outdoor wired or wireless network from a transmitter to a receiver While conceptually simple the means of trans mitting the data from some point A to some point B are complicated and varied in i
46. coordinating the change of control of a wireless device from one access point to another These delays result because the two access points must transmit data back and forth to successfully perform a 10 15 20 25 30 35 40 45 50 55 60 65 24 handoff Thus the prediction of handoff delay time is similar to the prediction of the packet latency time between the two access points To predict the handoff delay time the inven tion calculates the propagation transmission processing and queuing delays for the link between the two access points The invention then adjusts for the specific number of trans missions required and the size of the data which must be sent to successfully perform a handoff When predicting bit error rates the invention considers wired and wireless error rates Wireless networks operate in much more hostile electrical environments than their wired counterparts and their interconnections are significantly more difficult to model and until this invention practical networks have not successfully been modeled using specific accurate physical and electrical models of multiple trans mitters multiple interferers noise sources and network components within a 3 D site specific environment This invention uses 3 D site specific representations of the envi ronment for specific network implementations that are able to consider both wired and wireless networks and considers physical locations
47. d configuration settings but it can also predict the effects of just the hardware and firmware just the software or of a single configuration setting The ability of the invention to measure and thus adjust empirically derived predictions for these effects allows the optimization of the data communications network By predicting the effects of changing any detailed aspect of the data communications network a user can immediately visualize the effect of a new component or a setting change This ability allows a user skilled in the art to design an optimal data communications network by continually making changes and observing the prediction changes 10 15 20 30 35 40 45 50 55 60 65 20 We now focus on the details for predicting values for network performance parameters based on knowledge of the 3 D site specific environment as well as the specific com ponents used in the network design The throughput and bandwidth of a network are calcu lated by the invention as functions of any or all of the following operational parameters which impact perfor mance distance between transmitter and receiver physical environment specification packet sizes error and source coding schemes packet overhead modulation techniques environment interference signal strength number of users and for wireless networks the antenna pattern and type multipath delay number of multipath components angle of arrival of multipath
48. d optimization and is illustrated in FIG 6 FIG 7 and FIG 8 The method for optimizing a network using just measurements is shown in FIG 6 just predictions in FIG 7 and a combination of measurements and predictions in FIG 8 The process of optimizing a data communications net work is accomplished by comparing through numerical visual or some other means the predictions and measure ments of performance criteria such as throughput band width quality of service bit error rate packet error rate frame error rate dropped packet rate packet latency round trip time propagation delay transmission delay processing delay queuing delay network capacity packet jitter band width delay product and handoff delay time for various site specific locations and particular times of day By chang ing the hardware used in the network or changing the locations of hardware or the configuration of that hardware firmware or software which controls each device within the network one skilled in the art can improve the performance of the network These performance improvements can implemented and viewed by repeating predictions of the performance criteria after site specific equipment changes to the network have been made in the 3 D model of the network Continuing this process allows one skilled in the art to optimize the performance of a network to achieve an efficient data communications network Using this information the preferred embodim
49. der OTHER PUBLICATIONS in Column 2 Line 10 delete Enviroment and insert Environment therefor On Page 3 item 56 under OTHER PUBLICATIONS in Column 2 Line 11 delete Utllity and insert Utility therefor Signed and Sealed this Twentieth Day of November 2012 d David J Kappos Director of the United States Patent and Trademark Office CERTIFICATE OF CORRECTION continued Page 2 of2 U S Pat No 6 973 622 B1 On Page 3 item 56 under OTHER PUBLICATIONS in Column 2 Line 20 delete Enviroment and insert Environment therefor In Column 1 Line 23 delete as well and insert as well as therefor In Column 7 Line 8 delete Visonael and insert Visionael therefor In Column 7 Line 14 delete Visonael and insert Visionael therefor In Column 7 Line 27 delete WIZARDS and insert WIZARDS therefor In Column 11 Line 62 delete network and insert network therefor In Column 11 Line 63 delete signal and insert signal therefor In Column 12 Line 2 delete environment and insert environment therefor In Column 12 Line 4 delete predictions and insert predictions therefor In Column 12 Line 6 delete measurements and insert measurements therefor In Column 16 Line 10 delete are and insert art therefor In Column 20 Line 27 delete enging a
50. device or devices These software programs are called agents By sending test trans missions between two agents across a specific network connection the preferred invention can measure any particu lar performance criterion The results of these measurements are stored for a particular portion of the network The preferred embodiment of the invention can also import the logfiles of other measurement programs such as traceroute to measure specific links This functionality allows site specific measurements made by external pro grams to be stored site specifically This is accomplished by a two pass method described in patent 09 221 985 System for Creating a computer model and measurement database of a wireless communication network by T Rappaport and R Skidmore filed Dec 29 1998 To import a logfile a user simply clicks a point in the model of the environment for each data point to assign a location for each point in the logfile In performing network performance measurements espe cially for wireless data networks it is important to know the difference in performance for transmission and reception This is why the preferred invention can measure the trans mission and reception components of the average network statistics To measure the transmission direction the size of test packets is varied By changing the size of the packet sent and the size of the packet returned the transmission and reception statistics can be separated T
51. different components in said computerized model 47 The method of claim 46 wherein said step of updating further includes the step of specifying an orientation for at least one component specified in said specifying compo nents step at said location specified in said specifying locations step 48 The method of claim 37 wherein said computerized model identifies orientations of one or more of said one or more components at said locations within said physical space and said predicting step utilizes said orientations 49 The method of claim 37 wherein said computerized model includes one or more objects which create noise or interference said noise or interference being an attribute of said one or more objects which are factored in said predict ing step 50 The method of claim 37 wherein said one or more performance metrics predicted in said predicting step are predicted in a forward direction in said communication network 51 The method of claim 37 wherein said one or more performance metrics predicted in said predicting step are predicted in a reverse direction in said communication network 52 The method of claim 37 further comprising the step of specifying data transfer protocol and wherein said predict ing step uses a specified data transfer protocol as a factor in predicting said performance metric 53 The method of claim 37 further comprising the step of specifying a network loading for said communications net work and whe
52. e Predicting bit error rates data throughput delay and quality of service metrics in a 3 D physical model of an actual site specific environment is a very difficult task and one which has not been solved heretofore since different modem vendors have different and often times proprietary methods for mitigating or dealing with multipath multiple access interference protocol type packet size and noise That is the state of the art shows how to measure and display and make predictions for basic communication metrics but does not provide specific prediction algorithms for a wide range of important data network performance parameters in a reliable site specific manner Simply put a wireless net work performance prediction engine which is able to con sider an accurately modeled 3 D physical environment and which exploits knowledge of specific component layouts is not found in the prior art and is not obvious due to the complex nature of having to account for all possible physi cal electrical and logical factors for all components in a 10 15 20 25 30 35 40 45 50 55 60 65 10 network as well as the factors within the channel of a wired or wireless network that lead to actual network perfor mance Prior published papers in the area of communications networks do not demonstrate the ability of any invention to accurately predict three dimensional site specific network performance criteria The pa
53. e data collectors are routinely or periodically collected and then transmitted either by wireless or wired means or by real time or stored means to a server processor which is either collocated or remotely located from one or more of the measurement agents For example the measurements may be recorded by autonomous agents and then transmitted over a fixed network to a processor that integrates all measurements and computes statistics for observation The measurement sources have known positions in 3 D or may not be known and used to form a gross estimate of observed network performance The collected measurements may be sent in real time stored and forwarded or sent as file transfers via many means such as via email over the world wide web via wireless wired or optical links or in a storage device This in situ measurement data is passed with the 3 D position location when available to the server which catalogues and processes the specific measurement informa tion Using the measurement information from the data collectors the server is able to provide a predictive model by using knowledge of the physical 3 D environment and by fusing the many collected inputs into a simplified model of performance that is related to the 3 D physical representa tion of the world In the preferred embodiment of the invention the server stores and processes the physical location of all measure ment devices where available as well as all
54. e method of claim 9 wherein said step of updating includes the steps of specifying components from a plurality of different mod eled components which are to be used in said commu nications network said modeled components including descriptions and attributes of a specific component and specifying locations within said physical space for a plurality of different components in said computerized model 11 The method of claim 10 wherein said step of updating further includes the step of specifying an orientation for at least one component specified in said first specifying step at said location specified in said second specifying step 12 The method of claim 1 wherein said computerized model identifies orientations of said components at said locations within said physical space and said predicting step utilizes said orientations 13 The method of claim 1 wherein said computerized model includes one or more objects which create noise or US 6 973 622 B1 31 interference said noise or interference being an attribute of said one or more objects which are factored in said predict ing step 14 The method of claim 1 wherein said one or more performance metrics predicted in said predicting step are predicted in a forward direction in said wireless communi cation network 15 The method of claim 1 wherein said one or more performance metrics predicted in said predicting step are predicted in a reverse direction in said wireless commu
55. electrical specifications and attributes of all radiating sources and their antenna systems in a real world 3 D environmental model Wireless networks are prone to data errors much more so than wired channels due to the impact of multipath propagation multiple transmit ters and noise as described previously The fact that radio propagation and noise is more random than for fixed wired networks must be considered for practical design and is modeled in this invention For wired channels bit error rates are simply a measure of the electrical optical and electro magnetic parameters of a connection and are predicted using a statistical random variable such as a Gaussian or Poisson random distribution or other sensible distribution or algo rithm known now or in the future and this random variable is overlaid about the average median or typical perfor mance of the network component or network subsystem The network device or subsystem may include a single wireless node such as a router or switch or a complete interconnection of various routers hubs switches wireless access points and wireless client server devices that com municate with the network The network may be wired wireless or a combination thereof Many performance metrics of a device or a network subsystem such as Frame Error Rate Bit Error Rate or Packet Error Rate as well as other performance parameters such as throughput bandwidth quality of service bit error
56. ence and for wireless networks may include path loss multipath delay number of multipath components angular spread strength and angle of arrival of received signals modulation bandwidth and other physical electrical and logical settings of particular equipment in the network and the constants or functions may be calculated analyti cally predicted for an initial guess or solved using best fit methods between measured and predicted performance of actual networks in a site specific environment It is important to note that multipath delay and its effect on network performance prediction and design may be considered in many ways as contemplated by this invention and as shown in Equation 1 First multipath may be considered individually whereby each multipath component is considered to arrive from each transmitting device and the methods for modeling multipath are well known and explained in the prior art and in numerous research works by Rappaport et al from Virginia Tech Alternatively gross multipath effects may be modeled as having a worst case delay e g propagation distance d being approximated by the maximum average or median length of the specific building or 3 D environment in which the communication network is modeled Alternatively spatial considerations may be used by contemplating the antenna patterns of each transmitter or receiver so that multipath which arrives only in the main beam of each wireless device
57. ent of the invention can make recommendations for the areas of the network to upgrade or reconfigure The invention can also use SNMP protocol communications or other protocols to actually implement these changes That is a network designer could identify problems in a data communications network through prediction whereby the prediction of per formance criteria of the data communications network is calculated using known measurement data and the configu ration and expected performance of all data communications hardware in the data communications network The pre dicted performance criterion is stored and displayed visually and numerically in a location specific three dimensional model of the environment Then the designer can use the invention to identify a solution to the problems that are apparent by viewing the prediction results either by follow ing the inventions recommendations for changes or making the designers own change After simulating the predicted outcome the network designer can then direct the invention to update all the relevant settings of the equipment with the changes the designer has just used in a prediction The designer could then use the tool to measure the results of these changes using the measurement features of the inven tion While this invention has been described in terms of its preferred embodiments those skilled in the art will recog nize that the invention can be practiced with considerable variatio
58. ention uses specific 3 D modeling and therefore allows highly accurate asset man agement and facilities tracking of actual installed equipment while simultaneously providing for network performance prediction measurement and design capabilities that exploit the exact physical dimensioning of the network In addition the invention simultaneously stores an inventory of impor tant network specific and equipment specific characteriza tions of all objects used in the network such as vendor model number network hardware type operating system version firmware and software type and version The hier archical tree based model of the network is termed the Layout View The physically accurate site specific model of the network is termed the Site View whereby the attributes of each device can be displayed stored or printed by selecting a particular item or node within the 3 D environ mental model Further network hardware and software components can be interactively replaced removed recon figured or moved to a new location in real time using either the Layout View or the Site View Each of these ways of tracking and designing a network in a 3 D site specific model of the environment with accurate dimensioning of true spatial position are further described below and are used to create a Bill of Materials for the modeled data commu nications network whereby a preferred embodiment is described in co pending patent application Method and
59. formance of a wireless LAN network Maeda Y Takaya K and Kuwabara N Experimental Investigation of Propagation Characteristics of 2 4 GHz ISM Band Wireless LAN in Various Indoor Environments IEICE Transactions in Communications Vol E82 B No 10 Oct 1999 The measurements were tracked in a small highly radio frequency RF controlled environment and indicated that the wireless LAN throughput and BER were correlated to the delay spread of the wireless channel The researchers have not however presented any way to actually predict a bit error rate or throughput from the predicted delay spread profile output by a ray tracing tech nique Duchamp and Reynolds have presented IEEE 802 11 wireless LAN packet throughput measurement results for varying distances in Duchamp D and Reynolds N F Measured Performance of a Wireless LAN Local Com puter Networks 1992 Proceedings 17th Conference on 1992 These measurements were performed in a single hallway Thus these measurements too suffer from failing to measure a representative environment The researches did not present a model to predict their results nor did they attempt to validate any sort of computer prediction tech nique Bing has also presented measured results of the perfor mance of IEEE 802 11 Wireless LAN in Measured Perfor mance of the IEEE 802 11 Wireless LAN Local Computer Networks 1999 LCN 99 Conference on 1999 Bing pre sents delay and
60. g and Micro cellular Wireless Communication System Design Tool The Bradley Dept of Electrical Engineering Virginia Tech Univ MPRG TR 97 13 Jun 1997 Valenzuela R A A ray tracing approach to predicting Indoor Wireless Transmission IEEE 1993 Santarini M EETimes article Cadence offers XML based PCB library tool Published Apr 24 2000 pp 1 4 http www eetimes com story OEG2000042480031 Welch B et all Web Enabling Applications Fifth Annual Tcl Tk Workshop USENIX 1997 pp 189 190 of the Pro ceedings 4 pg printout from web Website WiSE Design of Indoor amp Outdoor Wireless Sys tem http web archive org web1200212190834211 www belllabs comlorglwireless 1wisext html Dec 2002 Fortune S et al Wise design of indoor wireless system practical computation and optimization Publication Date Spring 1995 vol 2 Issue 1 pp 58 68 Hansen W Rendering Tcl TK windows as HTML Mar 5 2003 Carnegie Mellon University Landron O et al A comparison of theoretical and empiri cal reflection coefficients for typical exterior wall surfaces in a mobile radio environment Antennas and Propagation IEEE Transactions pp 341 351 vol 44 Issue 3 Mar 1996 Valenzula R et al Estimating local mean signal strength of indoor multipath propagation Vehicular Technology IEEE Transaction pp 203 212 vol 46 Issue 1 Feb 1997 Skidmore et al Towards Integrated
61. gns such as packet size equalizer deployment modulation methodol ogy source and error coding methods packet protocols as well as the number of co channel network users the type of persistency used for packet retransmission or the multipath propagation effects in a wireless system provide additional factors that must be considered in the design of a commu nication network that is designed for data traffic as opposed to simply voice traffic One difficulty that today s network designer or network system administrator faces is that most networking equip ment uses proprietary non public methods for implementing various network devices and these methods vary by specific vendor Thus it is difficult to form reliable prediction models by just using basic physical propagation models in a wireless network for example As data transmission technologies such as Bluetooth DSL Voice over IP and future packet based cellular radio network architectures proliferate the ability to predict and measure specific network performance parameters will become increasingly important and the 10 15 20 25 30 35 40 45 50 55 60 65 14 ability to properly incorporate measurements into 3 D pre diction models for performance parameters will be impor tant for proper network deployment This invention considers attributes relevant to packet switched data communication networks which require more extensive and non obviou
62. her network performance criteria are packet jitter and bandwidth delay product Packet jitter is the variation in the arrival time of packets that are expected to arrive at a regular rate and is typically measured in time units of seconds A bandwidth delay product is the number of bits that can be sent from a transmitter before the first bit sent actually reached the receiver The bandwidth delay product is found by multiplying the packet latency of a certain link by the bandwidth of the same link Handoffs occur in wireless data networks when a user moves out of range of one access point and into range of another access point In this situation the first access point must pass the responsibility of delivering data to the wireless user to the second access point The handoff time is the amount of time required by an access point to coordinate with another access point to allow a wireless user to connect from one access point to another access point Software utilities and hardware devices have been devel oped to measure the performance statistics of data commu nication networks throughout the lifetime of data commu nication networks Some of the more common and relevant tools are briefly described here A large number of command line tools are available to quickly allow a computer user to measure the approximate network performance a connection Many command line programs are widely used on Windows UNIX and Macin tosh operating systems and
63. herein the at least one component that participates in communicating information over the wireless communications network having settings or configurations changed based on said instructions com prises network equipment and wherein the instructions are provided from the computer or server to the network equip ment based upon the one or more performance metrics for said wireless communications network to thereby improve the performance of the wireless communications network 109 A site specific system or apparatus for analyzing and adjusting a communications network comprising a computer or server for generating or using a computer ized model of a communications network positioned within a physical space said computerized model pro viding a site specific representation of one or more of a floor plan building layout terrain characteristics or RF characteristics said computerized model identify ing locations within said physical space of one or more components that participate in communicating infor mation over said communications network said com puterized model having modeled attributes for at least one of said one or more components one or more measurement collectors or agents positioned within said physical space which obtain and send mea surement data to said computer or server said com puter or server predicting one or more performance metrics for said communications network based on said measurement data and said modeled a
64. his allows a network designer to identify problems in transmission that might otherwise be masked by apparently good reception Network performance measurements are not useful if the measurements do not mimic the actual data traffic that a network carries For this reason the preferred embodiment 10 15 20 25 30 35 40 45 50 55 60 65 18 of the invention is able to mimic the traffic patterns network protocols and packet characteristics of actual data Thus if web browsing performance is being measured the invention sends small packets from an access terminal to a web server and returns large packets from that server that are typical of text image and web script file formats By measuring the performance of such packets the invention accumulates accurate network statistics for expected web browsing per formance The measurements of specific traffic types may also be applied to the use of broadcast or multicast packet perfor mance scenarios The preferred embodiment of the inven tion is able to measure performance of multiple transmitters or multiple receivers or both of the same packet information The performance of this type of transmission are different than point to point measurement because shared resources are used more efficiently in broadcast and multicast sce narios Thus the ability of the invention to measure network performance statistics for the overall success of the broad cast or multic
65. hub switch or computer to transmit an acknowledgement to the test packets This means that hidden links that do not transmit acknowledge ments such as Ethernet bridges can not be measured indi vidually by pathchar Several companies produce network measurement moni toring tracking and forecasting utilities Some of the com monly used utilities are discussed below The tools selected are illustrative of the state of the art of network performance measurement and asset tracking netViz made by netViz Corporation is a visual database program that allows a network administrator to track net work equipment in terms of its physical location and in terms of its logical layout This program allows the user to input the settings locations and configurations of the net work and track the assets in your network The tool is capable of storing this data in a two dimensional geographic map or floor plan of a building but can not track devices in a three dimensional manner The tool also does not provide network testing measurement or monitoring features nor does it support communication prediction or performance visualization capabilities for data communication networks It is simply a database for accurate and useful tracking of assets NetIQ Corporation was Ganymede Software Inc makes a network monitoring and forecasting tool called Chariot Chariot is able to measure throughput and many other network statistics for all popular network
66. hysical space of one or more components that participate in communicating infor mation over said wireless communications network said computerized model having modeled attributes for at least one of said one or more components downloading or inputting files of measurement data to said computer or server where said measurement data is obtained from said physical space or from said wire less communications network predicting or providing one or more performance metrics for said wireless communications network based on US 6 973 622 C1 5 said measurement data and said modeled attributes for said at least one of said one or more components and changing settings or configurations of at least one compo nent that participates in communicating information over said wireless communications network based on instructions sent from said computer or server 94 The method of claim 93 wherein the instructions are sent from said computer or server to said at least one com ponent that participates in communicating information over the wireless communications network to update relevant set tings of the at least one component based upon the predic tions 95 The method of claim 93 wherein the instructions are based upon the one or more predicted performance metrics for said wireless communications network 96 The method of claim 93 wherein the at least one com ponent that participates in communicating information over the wireless communic
67. ia Polytechnic Institute and State University Nov 13 1992 p 1 59 EDX Signal Pro 1996 p 1 13 Retrieved from Internet URL http www edx com products sp php on Sep 12 2005 Alex Berson Client Server Architecture New York McGraw Hill Inc 1992 pp i ii xxi 5 8 11 12 30 31 77 78 81 999 112 119 278 431 and 439 T S Rappaport et al SitePlanner 3 0 User s Manual c 1998 Wireless Valley Communication Inc all pages US 6 973 622 C1 1 EX PARTE REEXAMINATION CERTIFICATE ISSUED UNDER 35 U S C 307 THE PATENT IS HEREBY AMENDED AS INDICATED BELOW Matter enclosed in heavy brackets appeared in the patent but has been deleted and is no longer a part of the patent matter printed in italics indicates additions made to the patent AS A RESULT OF REEXAMINATION IT HAS BEEN DETERMINED THAT The patentability of claims 1 68 is confirmed New claims 69 116 are added and determined to be pat entable 69 A method for analyzing and adjusting a wireless com munications network comprising the steps of generating or using with a computer or server a comput erized model of a wireless communications network within a physical space in which said wireless commu nications network is deployed said computerized model providing a site specific representation of one or more of a floor plan building layout terrain characteristics or RF characteristics said computer ized model identify
68. ier that the network uses to forward the packet to the correct receiver The header and footer information are often used to reassemble the packet with other packets to reform the original message and to check if errors were made in the transmission of the packet The receiver can assembles all received packets into the original message by throwing away the header and footer headings and reassembling the data bits from all packets into the original message Packet switched networks are classified as connection oriented or connectionless depending on how the packets are transferred In connection oriented networks a network channel is used predefined for each transmission While this transmission can consist of multiple packets the route from transmitter to receiver is already established so that all packets sent on this channel can immediately be sent directly to the receiver Whereas in connectionless networks pack ets are sent simultaneously on a shared channel in multiple transmissions In this case packets require an identifier that gives the address of the receiver This address is understood by the communications network to allow the packet to be properly sent to the correct receiver Since each packet can be transmitted separately and thus interleaved in time with packets from other transmissions it is generally more effi cient to use a connectionless transmission method when using shared network resources An example of a connectio
69. ing UHF Propagation on Single Floors in Modern Office Buildings IEEE Transactions on Vehicular Technology vol 41 No 4 Nov 1992 pp 496 504 SMT Plus Site Modeling Tool A Software Tool for Plan ning Indoor Wireless Systems 2001 Printed from http www mprg org research smt smt shtm on Mar 5 2004 MPRG Industrial Affiliate Program 2001 Printed from http www mprg org partnerships affiliate shtm on Mar 5 2004 US 6 973 622 C1 Page3 Wireless Research Leads to Indoor Planning Tool EE Connection Feb 1997 Printed from http w ecpe vt edu ecenews feb97 smt html on Mar 5 2004 VTIP Disclosure No 96 013 Virginia Tech Intellectual Properties Inc 1997 2001 Printed from http www vtip org licensing disclosures 96 0 3 htm on Mar 5 2004 Communication Products Special Section EDN Access Aug 1 1996 Printed from http www e insite net ednmag archives 1996 080196 16dfl htm on Mar 5 2004 Panjwani et al Interactive Computation of Coverage Regions for Wireless Communication in Multifloored Indoor Environments IEEE Journal of Selected Areas in Commu nication Apr 1996 pp 420 430 Skidmore et al Interactive Coverage Region and System Design Simulation for Wireless Communication Systems in Multifloored Indoor Environments SMT Plus Sth Int l Conference on Universal Personal Communications Sep 29 Oct 2 1996 pp 646 650 Skidmore et al A Comprehensive In Buildin
70. ing locations within said physical space of one or more components that participate in communicating information over said wireless commu nications network said computerized model having modeled attributes for at least one of said one or more components receiving at said computer or server measurement data from one or more measurement collectors or agents located in said physical space said one or more mea surement collectors or agents being the same or differ ent from one or more of said one or more components used in said wireless communications network predicting at said computer or server one or more per formance metrics for said wireless communications networks wherein predictions are made based on said modeled attributes for said at least one of said one or more components and said measurement data from said one or more measurement collectors or agents and changing settings or configurations of at least one compo nent that participates in communicating information over the wireless communications network based on instructions sent from said computer or server 70 The method of claim 69 wherein the instructions are sent from said computer or server to said at least one com ponent that participates in communicating information over the wireless communications network to update relevant set tings of the at least one component based upon the predic tions 71 The method of claim 69 wherein the instructions are based upo
71. ireless com munications network comprising the steps of generating or using with a computer or server a comput erized model of a wireless communications network that is in a three dimensional space in which said wire less communications network is deployed said comput erized model providing a site specific representation of one or more of a floor plan building layout terrain characteristics or RF characteristics said computer ized model identifying locations within said three dimensional space of one or more components that par ticipate in communicating information over said wireless communications network said computerized model having modeled attributes that are measured predicted or calculated for at least one of said one or more components receiving at said computer or server measurement data from one or more measurement collectors or agents located in said three dimensional space said one or more measurement collectors or agents being the same or different from one or more of said one or more com ponents used in said wireless communications net works predicting at said computer or server one or more per formance metrics for said wireless communications network wherein predictions are made based on said modeled attributes for said at least one of said one or more components and said measurement data from said one or more measurement collectors or agents and changing settings or configurations of at least
72. irless Review Magazine May 2000 Slides from T S Rappaport and R Skidmore Introduction to In Building Wireless Systems Infocast In Building Wireless Solutions Conference and Exposition Feb 4 2003 S Sandhu M P Koushik and T S Rappaport Predicted Path Loss for Roslyn VA First set of predictions for ORD Projection Site Specific Propagation Prediction MPRG Technical Report MPRG TR 94 20 Virginia Tech Dec 1994 S Sandhu M P Koushik and T S Rappaport Predicted Path Loss for Roslyn VA First set of predictions for ORD Projection Site Specific Propagation Prediction MPRG Technical Report MPRG TR 94 20 Virginia Tech Mar 1995 S Seidel et al Site Specific Propagation Prediction for Wireless In Building Personal Communications Design IEEE Transactions on Vehicular Technology vol 43 No 4 Nov 1994 S Shakkottai and T S Rappaport Research Challenges in Wireless Networks A Technical Overview Proceeding of the Fifth International Symposium on Wireles Personal Multimedia Communications Honolulu HI Oct 2002 H Sherali et al On the Optimal Location of Transmitters for Micro cellular Radio Communication System Design IEEE Journal on Selected Areas in Communications vol vol 14 No 3 pp 662 673 May 1996 R Skidmore et al A Comprehensive In Building and Microcellular Wireless Communication System Design Tool The Bradley Department of Electrical Engineering MPR
73. is considered in the calculation of delay and in network performance in 1 Alternatively only the strongest one or two or some finite number of transmitters may be considered for multipath propagation delays whereby only a finite set of transmitters such as those most closest to the receiver of interest or those of a certain standard frequency or power setting are considered to radiate multipath energy and produce RSSI values and from that finite number of transmitters only the strongest multipath or the average maximum median or largest few multipath components are considered in com putation of delay Alternatively if only a finite number of transmitters are considered methods described above such as consideration of the physical environment to determine a gross multipath delay from each transmitter or the use of a particular antenna pattern to determine most important mul tipath components may be used to drive the model of multipath and its impact on network performance Similar approaches may be used to model the received signal strength RSSI in equation 1 Note that the constants or functions of equation 1 may be assigned blindly for initial predictions and then a specific network within the site specific environment may be mea sured empirically so that a best fit using a minimum mean square error approach or some other well known method may be used to assign values for the constants or functions in 1 Note that in
74. koff et al 5 485 568 A 1 1996 Venable et al 5 491 644 A 2 1996 Pickering et al 5 491 837 A 2 1996 Haartsen 5 493 679 A 2 1996 Virgil et al 5 515 269 A 5 1996 Willis et al 5 528 518 A 6 1996 Bradshaw et al 5 539 665 A 7 1996 Lamming et al 5 553 312 A 9 1996 Gattey et al 5 553 620 A 9 1996 Snider et al 5 555 354 A 9 1996 Strasnick et al 5 561 841 A 10 1996 Markus 5 564 070 A 10 1996 Want et al 5 586 254 A 12 1996 Kondo 5 594 946 A 1 1997 Menich et al 5 598 532 A 1 1997 Liron 5 625 827 A 4 1997 Krause et al 5 636 344 A 6 1997 Lewis 5 689 355 A 11 1997 Okubo et al Continued OTHER PUBLICATIONS Article Building Database Manipulator Copyright Jan 1998 MPRG and Virginia Tech Continued Primary Examiner Larry D Donaghue 74 Attorney Agent or Firm Whitham Curtis amp Christofferson PC 57 ABSTRACT A system and method for design tracking measurement prediction and optimization of data communications net works includes a site specific model of the physical envi ronment and performs a wide variety of different calcula tions for predicting network performance using a combination of prediction modes and measurement data based on the components used in the communications net works the physical environment and radio propagation characteristics 68 Claims 6 Drawing Sheets Method for optimizing a data communications network using predictions and measurements Data communications
75. lay product handoff delay time signal to interface ratio signal to noise ratio physical equipment price cost information 25 The system or apparatus of claim 20 further compris ing a storage device for storing said measurement data 26 The system or apparatus of claim 20 wherein said computerized model is stored on at least one server wherein said at least one server is the same or different from said computer or server 27 The system or apparatus of claim 26 wherein said computerized model is stored on a plurality of servers and said plurality of servers can communicate with each other 28 The system or apparatus of claim 27 wherein said plurality of servers have a heirarchical relationship to one another 29 The system or apparatus of claim 26 further compris ing at least one portable client device said at least one portable client device can communicate with said at least one server 30 The system or apparatus of claim 28 wherein said system includes a plurality of portable client devices 31 The system or apparatus of claim 20 further compris ing a storage medium or display for respectively storing or visualizing data representing comparisons of measurements with predictions 32 The system or apparatus of claim 20 further compris ing a storage medium or display for respectively storing or visualizing either or both logical connections of network components or physical locations of network components 33 A me
76. me fit to measured data an empirically based model These field measurements may be made manually or autonomously using data collectors or agents that continually measure and update the specific network performance metrics that are observed within the physical environment These data collectors are able to measure or are assigned specific 3 D position locations within the physical environment such position locations corresponding to known positions in the computer model which is used to model the physical environment of the US 6 973 622 B1 15 network and which are known or which are transmitted to a measurement server The data collectors may be individu als who manually or automatically record or collect observed network performance such as one or more of the aforementioned performance parameters or the measure ment agents may be software or hardware or firmware applications that run on top of network applications for the purpose of routinely measuring for one of more of the numerous network performance parameters listed previ ously The agents may be fixed or may be portable and may have position location devices such as GPS or inertial navigation or an internal map which is activated by a user so that the position location of the measurement is sent to a server processor The agents are presumed to have two way communication with a server processor that may be collo cated or remotely located Measurements from one or mor
77. mmunications network comprising the steps of generating or using with a computer or server a comput erized model of a communications network positioned within a physical space said computerized model pro viding a site specific representation of one or more of a floor plan building layout terrain characteristics or RF characteristics said computerized model identify ing locations within said physical space of one or more components that participate in communicating infor mation over said communications network said com puterized model having modeled attributes for at least one of said one or more components receiving at said computer or server measurement data from one or more measurement collectors or agents located in said physical space said one or more mea surement collectors or agents being the same or differ ent from one or more of said one or more components used in said communications network predicting using said computer or server one or more performance metrics for said communications network wherein predictions are made based on said measure ment data and said modeled attributes for at least one of said one or more components changing settings or configurations of at least one compo nent that participates in communicating information over said communications network based on instruc tions sent from said computer or server 102 The method of claim 101 wherein the instructions are sent from said compute
78. mplementation Hundreds of protocols hardware devices software techniques and pro grams exist to handle how data is sent correctly and effi ciently The exact performance of a given data communica tion network is extremely difficult to predict or even measure because of this complexity and additionally because of the performance effects of the time varying nature of data communications networks and the channels they operate in Data communication network can be classified as either a circuit switched or a packet switched network Both network types use channels to transmit information A channel is a named communications path between users of a communi cations network A channel may consist of many different individual hardware devices and is a specific route between a transmitter and a receiver In a circuit switched network information is transmitted by way of an exclusively reserved channel A network channel is reserved for the sole use of a single transmission and bits are sent all at once An example of this is the transmission of a document using a fax machine In this case the fax machine converts the image of the document into pixels Each pixel is a small dot sized rectangular piece of the paper Each pixel is considered to be either black or white The data that will be transmitted is a series of bits that represent whether each dot is black or white When the message in this case an image of a document is ready to be sent from
79. munications network to thereby improve the performance of the wireless communications network 113 A site specific system or apparatus for analyzing and adjusting a communications network comprising a computer or server for generating or using a computer ized model of a communications network positioned within a three dimensional space said computerized model providing a site specific representation of one or more of a floor plan building layout terrain character istics or RF characteristics said computerized model identifying locations within said three dimensional space of one or more components that participate in communicating information over said communications network said computerized model having modeled attributes that are measured predicted or calculated for at least one of said one or more components one or more measurement collectors or agents positioned within said three dimensional space which obtain and send measurement data to said computer or server said computer or server predicting one or more perfor mance metrics for said communications network based on said measurement data and said modeled attributes Jor said at least one of said one or more components and said computer or server can send instructions to one or more components that participate in communi cating information over said communications network which cause settings or configurations of the one or more components to be changed 114 The system o
80. n the one or more predicted performance metrics for said wireless communications network 72 The method of claim 69 wherein the at least one com ponent that participates in communicating information over the wireless communications network having settings or configurations changed based on said instructions com prises network equipment and wherein the instructions are 20 25 30 35 40 45 50 55 60 65 2 provided from the computer or server to the network equip ment based upon the one or more predicted performance metrics for said wireless communications network to thereby improve the performance of the wireless communications network 73 The method of claim 69 wherein said instructions are transmitted from said computer or server to said at least one component that participates in communicating information over the wireless communications network using an SNMP protocol communication 74 The method of claim 69 wherein the instructions are provided based upon the one or more predicted performance metrics for said wireless communications network to thereby improve the performance of the network 75 The method of claim 69 wherein the at least one com ponent that participates in communicating information over the wireless communications network comprises network equipment 76 The method of claim 75 wherein the network equip ment comprises a wireless access point 77 A method for analyzing and adjusting a w
81. n within the scope of the appended claims What is claimed is 1 A method for analyzing and adjusting a wireless communications network comprising the steps of generating or using with a computer or server a com puterized model of a wireless communications network within a physical space in which said wireless com munications network is deployed said computerized 10 20 25 30 35 40 45 50 55 60 65 30 model providing a site specific representation of one or more of a floor plan building layout terrain charac teristics or RF characteristics said computerized model identifying locations within said physical space of one or more components used in said wireless communications network said computerized model having modeled attributes for at least one each of said one or more components receiving at said computer or server measurement data from one or more measurement collectors or agents located in said physical space said one or more mea surement collectors or agents being the same or differ ent from one or more of said one or more components used in said wireless communications network predicting at said computer or server one or more performance metrics for said wireless communications network wherein predictions are made based on said modeled attributes for said at least one of said one or more components and said measurement data from said one or more measurement collectors or agents
82. nd Apparatus for Planning a Cellular Radio Network by Creating a Model on a Digital Map Adding Properties and Optimizing Parameters Based on Statistical Simulation Results filed by O Markus US 6 973 622 B1 9 U S Pat No 5 794 128 entitled Apparatus and Processes for Realistic Simulation of Wireless Information Trans port Systems filed by K H Brockel et al U S Pat No 5 949 988 entitled Prediction System for RF Power Distribution filed by F Feisullin et al US Pat No 5 987 328 entitled Method and Device for Placement of Transmitters in Wireless Networks filed by A Ephremides and D Stamatelos USS Pat No 5 598 532 entitled Method and Apparatus for Optimizing Computer Networks filed by M Liron et al USS Pat No 5 953 669 entitled Method and Apparatus for Predicting Signal Characteristics in a Wireless Commu nication System filed by G Stratis et al U S Pat No 6 061 722 entitled Assessing Network Per formance without Interference with Normal Network Operations filed by W J Lipa et al U S Pat No 5 831 610 entitled Designing Networks filed by D L Tonelli et al U S Pat No 5 821 937 entitled Computer Method for Updating a Network Design filed by Tonelli et al U S Pat No 5 878 328 entitled Method and Apparatus for Wireless Communication System Organization filed by K K Chawla et al An existing product SitePlanner described in patent application Ser
83. nd insert engine therefor In Column 20 Line 34 in Equation 1 delete F and insert F therefor In Column 22 Line 20 delete intrest and insert interest therefor In Column 27 Line 64 delete y and insert y therefor In Column 30 Line 26 in Claim 3 after said delete data collection In Column 32 Line 14 in Claim 28 delete heirarchical and insert hierarchical therefor In Column 33 Line 22 in Claim 37 after components insert and therefor In Column 34 Line 55 in Claim 56 delete characteristics and insert characteristics therefor In Column 36 Line 16 in Claim 64 delete heirarchical and insert hierarchical therefor US006973622C1 a z EX PARTE REEXAMINATION CERTIFICATE 7346th United States Patent Rappaport et al 0 Number US 6 973 622 C1 54 SYSTEM AND METHOD FOR DESIGN TRACKING MEASUREMENT PREDICTION AND OPTIMIZATION OF DATA COMMUNICATION NETWORKS 75 Inventors Theodore Rappaport Salem VA US Roger Skidmore Blacksburg VA US Benjamin Henty Blacksburg VA US 73 Assignee Wireless Valley Communications Inc Blacksburg VA US Reexamination Request No 90 009 123 Apr 24 2008 Reexamination Certificate for Patent No 6 973 622 Issued Dec 6 2005 Appl No 09 668 145 Filed Sep 25 2000 Certificate of Correction issued Sep 5 2006 51 Int CI G06F 3 00 2006
84. nd received All data communication networks may be analyzed in some fashion to evaluate the efficiency and performance of the network as well as to confirm the network is functioning properly In order to evaluate the functionality of these data networks certain performance criterion is used These per formance criteria include but are not limited to throughput bandwidth quality of service bit error rate packet error rate frame error rate dropped packet rate packet latency round trip time propagation delay transmission delay pro cessing delay queuing delay network capacity packet jitter 10 15 20 25 30 35 40 45 50 55 60 65 4 bandwidth delay product and handoff delay time Each performance criterion specifies a different performance parameter of a data communications network These crite rions are further described below A link is a portion of a path followed by a message between a transmitter and a receiver in a data communica tions network Network connection often consists of indi vidual devices relaying network packets from the transmitter to the receiver This means a network connection can consist of several actual transmissions between the original trans mitter and the intended receiver Each individual relay is called a link Typically a full network connection consists of several links Performance criteria can be measured for each individual link Throughput is a measurement
85. network components and their electrical logical and technical con figuration while also considering cost and maintenance issues associated with each network component Using the preferred embodiment a data communications network can be designed deployed tested predicted measured opti mized and maintained by collecting the measured data from one or more agents and processing them at the server to determine a proper prediction engine that allows future network layout with a desired outcome prior to installation The server engine is able to display the measured results in a site specific manner from each measurement agent that has site specific information so that predictions may be compared to measurements on a visual display of a com puter or in a stored means such as an ASCII file comparing predicted versus measured performance parameters It is important to note that each measurement agent may be a server capable of fusing measurement data with the site specific 3 D layout of the network components and the physical environment Therefore each measurement agent may serve as a centralized processor as well so that many different physical locations of a particular network may be measured and predicted for performance Servers may then be collocated or remotely located from the measurement agents which collect display store and use the measure ments to form predictive models In the case of a remote 10 15 20 25 3
86. ng or visualizing data representing comparisons of measurements with predictions 36 The method of claim 33 further comprising the step of storing or visualizing data representing either or both logical connections of network components or physical locations of network components 37 A site specific method for analyzing and adjusting a communications network comprising the steps of US 6 973 622 B1 33 generating or using with a computer or server a com puterized model of a communications network posi tioned within a physical space said computerized model providing a site specific representation of one or more of a floor plan building layout terrain charac teristics or RF characteristics said computerized model identifying locations within said physical space of one or more components used in said communications network said computerized model having modeled attributes for at least one of said one or more compo nents receiving at said computer or server measurement data from one or more measurement collectors or agents located in said physical space said one or more mea surement collectors or agents being the same or differ ent from one or more of said one or more components used in said communications network predicting using said computer or server one or more performance metrics for said communications network wherein predictions are made based on said measure ment data and said modeled attributes for at leas
87. ni cation network 16 The method of claim 1 further comprising the step of specifying data transfer protocol and wherein said predict ing step uses a specified data transfer protocol as a factor in predicting said one or more performance metrics 17 The method of claim 1 further comprising the step of specifying a network loading for said wireless communica tions network and wherein said predicting step uses a specified network loading in predicting said one or more performance metrics 18 The method of claim 1 further comprising the step of storing or visualizing data representing comparisons of measurements with predictions 19 The method of claim 1 further comprising the step of storing or visualizing data representing either or both logical connections of network components or physical locations of network components 20 A system or apparatus for analyzing and adjusting a wireless communications network comprising a computer or server for generating or using a comput erized model of a wireless communications network positioned within a physical space said computerized model providing a site specific representation of one or more of a floor plan building layout terrain charac teristics or RF characteristics said computerized model identifying locations within said physical space of one or more components used in said wireless communications network said computerized model having modeled attributes for at least one of
88. nless packet based transmis sion is a file transfer between two computers on an internet protocol IP based Ethernet network that both computers are attached to In this case the file that is to be transmitted is fragmented at the transmitter into appropriate packets and labeled with the IP address which is the identifier used by the network to forward the packet to the correct receiver The packets are then sent from the transmitting computer to the receiving computer The Ethernet network is capable of supporting multiple file transfers from many different com puters all using the same network by controlling the flow of packets from each destination in a shared fashion The receiver then assembles the packets into an exact copy of the original file completing the transmission All data networks utilize some form of communication protocol to regulate the transmission and reception of infor mation A protocol is the set of rules that all hardware and software on a communication network must follow to allow proper communication of data to take place Many hundreds of protocols are in active use today in the worldwide exchange of information Some of these protocols such as the Transport Control Protocol TCP or the User Datagram Protocol UDP define the way in which the network is accessed Other protocols such as the Internet Protocol IP or the File Transfer Protocol FTP define how messages and packets are formatted transmitted a
89. ntation of one or more of a floor plan building layout terrain characteristics or RF characteristics said computer ized model indentifying locations within said physical space of one or more components that participate in communicating information over said wireless commu nications network said computerized model having modeled attributes for at least one of said one or more components one or more measurement collectors or agents operating or operational within said physical space which send measurement data to said computer or server said computer or server predicting one or more perfor mance metrics for said wireless communications net work based on said measurement data and said mod eled attributes for said at least one of said one or more components and said computer or server can send instructions to one or more components that participate in communicating information over said wireless com munications network which cause settings or configu rations of at least one component to be changed 82 The system or apparatus of claim 81 wherein the instructions are sent from said computer or server to said at least one component that participates in communicating information over the wireless communications network to update relevant settings of the at least one component based upon the one or more performance metrics for said wireless communications network 83 The system or apparatus of claim 81 wherein the instructions are based
90. of the signal at the receiver A B C C C C3 D E F K are constants or linear or non linear functions with different values depend ing on which of BER FER and PER is being calculated The value M may denote particular number of multipath components from a particular transmitter or may denote a combination of important multipath components from a collection of transmitters where the term important is based on antenna pattern physical environment distances and other wireless propagation factors which are well known to one skilled in the art and which are explained within this disclosure The each of M values of G and P represent gains and power levels respectively of different signal compo nents which may represent individual multipath compo nents or gross signal components from one or more radiating sources and may be in logarithmic or linear values of power The variables G and P and each one of the M number of K values may be in logarithmic e g dB or absolute values These constants in the above equation are dependant on distance d between transmitter and receiver where d may be the straight line or actual reflected diffracted distance of the main signal path between the serving transmitter and receiver As explained in the text surrounding equation 1 distance may be straight line distance or may be modeled from the gross characteristics of the environment such as the maximum average or median length of
91. on the invention uses formulas which include any or all of the environment three dimen sional position protocol type multipath delay packet sizes radio frequency radio frequency bandwidth coding num ber strength and angle of arrival of multipath components signal strength transmission propagation processing and queuing delay bit error rate packet error rate frame error rate throughput bandwidth and bandwidth delay product The formulas include constants or functions which relate the above variables in general to the variation in the arrival time of data and in specific to the QoS and packet jitter of a connection The present embodiment of the current inven tion uses equations 1 or 4 to determine QoS and packet jitter for a data communications network The preferred embodiment of the invention predictions consider the effects of not just the site specific floor plan building layout terrain characteristics and RF characteris US 6 973 622 B1 27 ties but also the effects of the particular network hardware firmware and software in the network The invention allows the network to be modeled down to the settings and locations of the individual data communications devices using the Bill of Materials discussed earlier The prediction of network performance statistics takes these settings into account This means that different transport level protocols such as TCP or UDP different protocol settings such as packet
92. on locations are used to measure in situ performance parameters that are transmitted to a server processor The server processor has an accurate 3 D model of the environ ment and is able to process the measured data and is also able to provide predictive models using site specific infor mation that may be independent of or may make use of measured data The server process is able to communicate with other server processors in a hierarchical manner such that data fusion from many remote or collocated networks may be assembled and used for display and cataloging of measurements that may or may not be used for creation of predictive performance models Alternatively each server processor is able to compute predictive performance models without the use of measured data by simply considering the site specific layout of physical components as well as the specific delay times transit times propagation effects and multipath and noise factors within the physical network The invention can predict throughput bandwidth quality of service bit error rate packet error rate frame error rate dropped packet rate packet latency round trip time propa gation delay transmission delay processing delay queuing delay network capacity packet jitter bandwidth delay prod uct and handoff delay time in a site specific three dimen sional model of any environment The invention can mea sure and predict all of the above performance criteria and store
93. one compo nent that participates in communicating information over the wireless communications network based on instructions sent from said computer or server 78 The method of claim 77 wherein the instructions are sent from said computer or server to said at least one com ponent that participates in communicating information over the wireless communications network to update relevant set tings of the at least one component based upon the predic tions 79 The method of claim 77 wherein the instructions are based upon the one or more predicted performance metrics for said wireless communications network 80 The method of claim 77 wherein the at least one com ponent that participates in communicating information over the wireless communications network having settings or configurations changed based on said instructions com US 6 973 622 C1 3 prises network equipment and wherein the instructions are provided from the computer or server to the network equip ment based upon the one or more predicted performance metrics for said wireless communications network to thereby improve the performance of the wireless communications network 81 A system or apparatus for analyzing and adjusting a wireless communications network comprising a computer or server for generating or using a computer ized model of a wireless communications network posi tioned within a physical space said computerized model providing a site specific represe
94. one fax machine to another a telephone circuit is dedicated to the data transfer by placing a telephone call on the plain old telephone system POTS communications network The telephone line is used exclusively by the fax transmission making it a circuit switched transmission After establishing a connection all data is sent from the first fax machine to the second in a single long stream of bits The bits in this case are trans mitted as different frequency tones on the telephone line A high pitched toned may represent a 1 while a low pitched tone may represent a 0 The receiving fax receives the bits of the message by translating the series of high and low pitch tones into data bits The receiving fax machine will then be able to reconstruct a copy of the original document by drawing a black dot at the locations indicated by the data bits Packet switched networks are another type of data com munication networks in which all data bits are transmitted as many small chunks of data bits called packets and sent individually from one location to another A packet is a US 6 973 622 B1 3 self contained portion of a full message that is made up of a header data bits and sometimes footer The packet con tains information in the header and footer that allows the data communications network to properly transmit the packet and to know of which message the data in the packet is a part The header generally is labeled with an identif
95. ons network said computerized model having modeled attributes that are measured predicted or calculated for at least one of said one or more components US 6 973 622 C1 7 receiving at said computer or server measurement data from one or more measurement collectors or agents located in said three dimensional space said one or more measurement collectors or agents being the same or different from one or more of said one or more com ponents that participate in communicating information over said communications network predicting using said computer or server one or more performance metrics for said communications network wherein predictions are made based on said measure ment data and said modeled attributes for at least one of said one or more components changing settings or configurations of at least one compo nent that participates in communicating information over said communications network based on instruc tions sent from said computer or server 106 The method of claim 105 wherein the instructions are sent from said computer or server to said at least one com ponent that participates in communicating information over the wireless communications network to update relevant set tings of the at least one component based upon the predic tions 107 The method of claim 105 wherein the instructions are based upon the one or more performance metrics for said wireless communications network 108 The method of claim 105 w
96. ork using the visualization capabilities of the invention Vary network software firmware and hardware settings or equipment locations to improve network performance Does the measured performance satisfy the design requirements for the network Result is the optimal network design based on measured performance criteria U S Patent Dec 6 2005 Sheet 6 of 6 US 6 973 622 B1 Figure8 Method for optimizing a data communications network using predictions and measurements Data communications network performance optimization using prediction and measurement Measure site specific data communications network for desired performance criteria Predict network performance using measurement data for accurate calculations In model adjust settings of network devices or hardware location or add new network equipment to improve performance Re generate performance predictions Compare predictions to performance goals Performance goals achieved Change hardware or software settings add additional hardware and change location of equipment as decided in above predictions Performance goals achieved Data communication network optimized to meet specific performance criteria US 6 973 622 B1 1 SYSTEM AND METHOD FOR DESIGN TRACKING MEASUREMENT PREDICTION AND OPTIMIZATION OF DATA COMMUNICATION NETWORKS CROSS REFERENCE TO RELATED APPLICATIONS This application is related to appli
97. ow U S Pat No 6 721 769 and pending application entitled System and Method for Efficiently Visualizing and Comparing Communication Net work System Performance Ser No 09 632 803 filed by T S Rappaport R R Skidmore and Brian Gold on Aug 4 2000 and co pending application Method and System for Automated Selection of Optimal Communication Network Equipment Model Position and Configuration in 3 D Ser No 09 667 689 filed by T S Rappaport R R Skidmore and P SheethalNath filed concurrently the subject matter of which is incorporated herein by reference BACKGROUND OF THE INVENTION 1 Field of the Invention The invention relates to the field of communications networks and more specifically to the design thereof and the measurement visualization prediction and optimization of the performance of data communication networks A method and system to predict visualize and optimize the performance of data communication networks is used to design measure monitor troubleshoot and improve these data networks using an accurate site specific model of the physical environment and the components comprising the data network 2 Description of the Related Art Communications networks are used to send information from one place to another This information often takes the form of voice video or data To transmit information a communications network breaks down a message into a series of numbers These numbers describe how to
98. per mentioned earlier by Maeda Y Takaya K and Kuwabara N Experimental Investigation of Propagation Characteristics of 2 4 GHz ISM Band Wireless LAN in Various Indoor Environments IEICE Transactions in Communications Vol E82 B No 10 Oct 1999 has demonstrated the ability to predict the delay spread of a wireless channel and that the prediction corre lates well with throughput but the described method is not actually able to predict throughput or any other network performance criteria While some prior art has demonstrated the ability to track network assets in a two dimensional manner with some physical accuracy these products have not contemplated the ability to predict future network per formance for similar or different physical environments e g installations Many products allow the measurement of network performance criteria but no prior art has contem plated a 3 D representation of the physical environment with the physical installed base of components for the purpose of predicting network performance parameters Furthermore no tool or invention exists that can directly measure track the assets of predict the network performance criteria of and visualize the network performance criteria of a data communications network in a three dimensional site spe cific manner Furthermore none of the prior art has considered an invention that can perform precise site specific three dimensional performance prediction of
99. ppaport et al Rappaport et al Awe et al Rappaport et al Krishnamachari et al Heil Sadri Rappaport et al Won et al King Heiska et al Lamb Jain et al Ghaffari Rappaport et al Skidmore et al Hou et al Anturna Fattouch Rappaport et al Rappaport et al Burkhardt et al Rappaport et al Trossen et al Rappaport et al Rappaport et al Zhang et al Skidmore et al Rappaport et al Mikurak Rappaport et al Carter Rappaport et al Rappaport et al Shur et al Rappaport et al Rappaport et al Rappaport et al Rappaport et al 7 295 960 B2 7 299 168 B2 2001 0051503 Al 2002 0023244 Al 2002 0028681 Al 2002 0030600 Al 2002 0046259 AI 2002 0075825 Al 2002 0082859 AI 2002 0095486 Al 2002 0177982 Al 2003 0023411 Al 2003 0050878 Al 2003 0229478 Al 2003 0232598 Al 2004 0002364 Al 2004 0017790 A1 2004 0038683 Al 2004 0072577 Al 2004 0077359 Al 2004 0090943 Al 2004 0133415 Al 2004 0143428 AI 2004 0162840 Al 2004 0177085 Al 2004 0186847 Al 2004 0202196 Al 2004 0211888 Al 2004 0259554 AI 2004 0259555 AI 2003 8013161 2005 0253751 Al 2005 0265321 Al 2006 0015814 Al 2006 0019679 Al 2006 0036406 Al 2006 0116853 Al 2007 0099622 Al 2007 0117567 Al 11 2007 Rappaport et al 11 2007 Rappaport et al 12 2001 Lush 2 2002 Hatanaka et al 3 2002 Lee et al 3 2002 Stamer et al 4 2002 Glorikian 6 2002 Hills et al 6 2002 Lancos et al 7 2002 Bahl 11 2002 Boulouednine et al 1 2003 Witmer et al 3
100. ptimization procedure needs a model of the environment and a model of data communications equipment Performance optimization of a data communications network using prediction Predict one or more performance criterion for the data communication network View the results of the predictions in the site specific model of the environment and the network using the visualization capabilities of the invention Does the predicted performance satisfy the design requirements for the network Vary network software and firmware settings hardware settings or equipment location to improve performance Implement the modeled network settings and locations in the actual data communication network Result is the optimal network design based on prediction of the desired performance criteria U S Patent Dec 6 2005 Sheet 5 of 6 US 6 973 622 B1 Figure 7 Method for optimizing a data communications network using measurements Measurement optimization procedure needs a model of the environment and the data communications equipment and site specific measurements of one or more performance criteria Performance optimization of a data communications network using measurement Collect site specific measurements of one or more performance criterion for the data communication network View the results of the measurements in the site specific model of the environment and the netw
101. r apparatus of claim 113 wherein the instructions are sent from said computer or server to said one or more components that participate in communicating information over the wireless communications network to update relevant settings of the one or more components based upon the one or more performance metrics for said wireless communications network 115 The system or apparaus of claim 113 wherein the instructions are based upon the one or more performance metrics for said wireless communications network 116 The system or apparatus of claim 113 wherein the one or more components that participate in communicating information over the wireless communications network hav ing settings or configurations changed based on said instructions comprises network equipment and wherein the instructions are provided from the computer or server to the network equipment based upon the one or more performance metrics for said wireless communications network to thereby improve the performance of the wireless communications network
102. r or server to said at least one com ponent that participates in communicating information over the wireless communications network to update relevant set tings of the at least one component based upon the predic tions 103 The method of claim 101 wherein the instructions are based upon the one or more performance metrics for said wireless communications network 104 The method of claim 101 wherein the at least one component that participates in communicating information over the wireless communications network having settings or configurations changed based on said instructions com prises network equipment and wherein the instructions are provided from the computer or server to the network equip ment based upon the one or more performance metrics for said wireless communications network to thereby improve the performance of the wireless communications network 105 A site specific method for analyzing and adjusting a communications network comprising the steps of generating or using with a computer or server a comput erized model of a communications network that is in a three dimensional space said computerized model pro viding a site specific representation of one or more of a floor plan building layout terrain characteristics or RF characteristics said computerized model identify ing locations within said three dimensional space of one or more components that participate in communi cating information over said communicati
103. rate packet error rate frame error rate dropped packet rate packet latency round trip time propagation delay transmis sion delay processing delay queuing delay network capac ity packet jitter bandwidth delay product and handoff delay time may be either derived from a specification of the equipment may be calculated analytically within the inven tion or inputted into the invention or may be measured a priori in advance to using the invention That is specific parameters of operation known as operating parameters or equipment parameters such as those listed previously can be either measured or predicted through equipment specifi cations provided by vendors Alternatively they may be measured in situ by a user or research facility for proper modeling and input into the invention Alternatively they may be calculated based on some known analytical model that contemplates interconnection of devices so that a per formance model and operating parameters may be com puted The statistical random variable to model network performance within the invention can be dependant on the electrical optical and electromagnetic characteristics of each device such as voltage levels power levels impedance US 6 973 622 B1 25 and operating frequencies or can be generated using a typical observed measured value for each network device For instance copper wire can be modeled as having a bit error rate of 1 error in 10 or 107 bits tran
104. rein said predicting step uses a specified network loading in predicting said one or more performance metrics 54 The method of claim 37 further comprising the step of storing or visualizing data representing comparisons of measurements with predictions 55 The method of claim 37 further comprising the step of storing or visualizing data representing either or both logical connections of network components or physical locations of network components 56 A site specific system or apparatus for analyzing and adjusting a communications network comprising a computer or server for generating or using a comput erized model of a communications network positioned within a physical space said computerized model pro viding a site specific representation of one or more of a floor plan building layout terrain characteristics or RF characteristics said computerized model identify ing locations within said physical space of one or more components used in said communications network said computerized model having modeled attributes for at least one of said one or more components one or more measurement collectors or agents positioned within said physical space which obtain and send measurement data to said computer or server said computer or server predicting one or more performance metrics for said communications network based on said measurement data and said modeled attributes for said at least one of said one or more components and said
105. requirements of the user Prediction of throughput bandwidth quality of service bit error rate packet error rate frame error rate dropped packet rate packet latency round trip time propagation delay transmission delay processing delay queuing delay network capacity packet jitter bandwidth delay product and handoff delay time and other performance parameters may be carried out by predicting the performance for all wired network components separately from the performance of wireless components and then combining the results to get the net network performance To predict the performance of a wired communication link it is important to combine the known effects of each piece of wired equipment for the specific network settings also known as operating or per formance parameters such as protocol type data type packet size and traffic usage characteristics firmware type operating system type typical network performance char acteristics and typical average peak and minimum traffic load on the network For wireless network components additional factors concerning propagation signal strength interference and noise must be considered The preferred embodiment of the invention allows data communication networks to be accurately characterized for performance prediction in a number of novel ways First performance prediction may be based on field measurements from an actual network where prediction models are formed from so
106. rformance of delay within the cable within the 3 D environment Additionally using a tool tip mouse cursor or some other pointing means or using a pull down menu or by simply viewing the display device which the invention is implemented on various network performance metrics as well as stored data from the Bill of Materials and parameters of intrest may be visualized or stored Predicting the propagation delay for a wireless portion of a data communications network is more difficult than wired networks due to the fact that multiple transmitter sources such as access points in a Bluetooth network IEEE 802 11b or wireless ATM network may be transmitting simulta neously Furthermore as mentioned previously multipath interference can create echoes that may or may not be equalized depending on the specific network equipment used at the wireless receiver or transmitter However the same calculation model used for wired networks may be used with the additional consideration of multipath delay terms and propagation losses or gains due to specific multipath components as shown in Equation 1 This additional consideration of multipath delay is needed to account for the fact that wireless data does not always travel in a straight line and that physical objects can diffract reflect absorb and scatter radio energy Thus to calculate the transmission delay of a wireless link in a data communications network the distance between the transmi
107. rocessing delay queuing delay network capacity packet jitter band width delay product and handoff delay time in a site specific three dimensionally accurate manner The invention con templated here allows novel distributed measurement tech niques for the above performance parameters Furthermore prediction methods for the above performance parameters are created which use network measurements or applied values derived from other means and which also use the US 6 973 622 B1 11 radio frequency environment the 3 D physical network layout the channel propagation characteristics of a site specific environment and the specific physical layout of components for the computation of predicted performance parameter values SUMMARY OF THE INVENTION The present invention is capable of predicting measuring and optimizing the performance of a data communications network The invention is capable of representing a detailed layout of a fully deployed or contemplated communications network within a physically accurate computer representa tion or model of a three dimensional environment This allows the invention to store measurements and determine performance predictions within a site specific representation of the physical environment while using specific informa tion about the network entities components subsystems and systems used to create the actual or contemplated network Measurement agents with known or assigned 3 D positi
108. rvation from net work equipment o reporting mechanisms built into hardware or software products By forming a table look up of the specific capacity results as a function of 3 D site specific location as well as the time of day the invention builds a measurement based predictive model for capacity These measurements may be used to form a model of capacity as now presented The invention contemplates the fact that the scaling factor on capacity or throughput is a function of the instanta neous number of users of the network the maximum number of simultaneous users of the network the average and maximum packet size used by users of the network and for many other factors that are modem or network or vendor or protocol specific Also in the case of a wireless network the multipath propagation effects the propagation distances between the user and the wireless access points and the received signal levels are factors that limit capacity In addition constants or functions that fuse the impact of modulation equalizations impulse noise and other factors are used in the invention Thus capacity or throughput of a network is modeled by Capacity C Ad B C 6 M C3 D RSST E RSSIY F 23 G P Kj i l where the constants or functions of 6 take on similar properties as described for equations 1 and 4 Further more the entire equation 6 may be scaled by K Umax where K is the instantaneous number of
109. s Predictions in Residential Enviroments IEEE Transactions on Vehicular Technology vol 48 No 3 May 1999 T S Rappaport et al Wireless Communication Past Events and a Future Perspective IEEE Communications Magazine May 2002 T S Rappaport et al Radio Propagation Prediction Techniques and Computer Aided Channeling Modeling for Embedded Wireless Microsystems ARPA Annual Report US 6 973 622 B1 Page 3 MPRG Technical Report MPRG TR 94 12 Virginia Tech Jul 1994 T S Rappaport et al Use of Topographic Maps with Building Information to Determine Antenna Placements for Radio Detection and Tracking in Urban Environments MPRG Technical Report MPRG TR 95 14 Virginia Tech Nov 1995 D Ullmo et al Wireless Propagation in Buildings A Statistical Scattering Approach IEEE Transactions on Vehicular Technology vol 48 No 3 May 1999 T S Rappaport wireless Communications Principles and Practice Second Edition Prentice Hall 2002 T S Rappaport et al Use of Topographic Maps with Building Information to Determine AntennaPlacements and GPS Satellite Coverage for Radio Detection and Tracking in Urban Environments MPRG Technical Report MPRG TR 95 14 Virginia Tech Sep 1995 T S Rappaport et al Indoor Path Loss Measurement for Homes and Apartments at 2 4 and 5 85 GHz private report produced for Motorola Dec 16 1997 T S Rappaport Isolating Interference W
110. s agents In this manner servers can be organized in a hierarchy or a distributed fashion This allows servers to report measurements to one another and make measurements using other agents or servers A net work designer at a server can then use all collected and reported data to identify problem areas such as fairness or poor distribution of broadcast data or problem times such as increased network activity at lunch time with a data communications network In order to improve the value of measurement data collected the preferred embodiment of the invention iden tifies the exact if possible or approximate location of a remote agent As discussed earlier remote agents in this case can either be controlled by a user at that physical location or controlled remotely by a server In the preferred embodi ment of the invention the agent uses information about the network layout to identify an approximate location Deter mining the nearest piece of network equipment and associ ating the approximate location with the precisely known location of that network equipment accomplishes this This approximate location can be further refined using dead reckoning clicking on a location in a map or using the global positioning system laser range finders or some other positioning device known now or in the future The preferred embodiment of the invention is not only capable of accounting for the effects of different hardware firmware software an
111. s modeling when compared to traditional cell phone or telephone voice communication systems that are circuit switched and use a dedicated single user or bounded number of users per assigned operating channel Data communication networks have performance criteria that are specific to packet based systems and that are not useful to all types of communication networks contem plated previously For this reason the preferred embodiment of the invention can additionally predict the throughput bandwidth quality of service bit error rate packet error rate frame error rate dropped packet rate packet latency round trip time propagation delay transmission delay pro cessing delay queuing delay network capacity packet jitter bandwidth delay product and handoff delay time based on the specific physical and spatial location of each network component as well as the physical electrical and logical attributes of the specific components The performance prediction methods take into account all devices and net work equipment including the physical locations within the 3 D modeled environment using the constructed Bill of Materials of the network within the 3 D modeled environ ment and is capable of performance predictions for any desired location in the modeled network and environment where a location may be within a room at a particular location in a room within a building or in an outdoor region of varying granularity depending on the
112. said one or more components one or more measurement collectors or agents operating or operational within said physical space which send measurement data to said computer or server said computer or server predicting one or more performance metrics for said wireless communications network based on said measurement data and said modeled attributes for said at least one of said one or more components and said computer or server can send instructions to one or more components of said wireless communications network which cause settings or con figurations of at least one component to be changed 21 The system or apparatus of claim 20 wherein said site specific representation is three dimensional 22 The system or apparatus of claim 20 wherein said measurement collectors or agents are portable or fixed 23 The system or apparatus of claim 20 wherein said measurement collectors or agents are permanently affixed at within said physical space 24 The system or apparatus of claim 20 wherein said performance metric predicted by said computer or server is selected from the group consisting of throughput error rates packet latency packet jitter symbol jitter quality of service security coverage area bandwidth bit error rate packet error rate frame error rate dropped packet rate queuing delay round trip time capacity signal level interference 10 15 20 25 30 35 40 45 50 60 65 32 level bandwidth de
113. sical electrical or logical environment of the network These constants or functions take on specific functional values depending upon if T or BW is being solved for The value M may denote a particular number of multipath components from a particular trans mitter as determined by propagation analysis of the channel or the term may denote a combination of important multi path components from a collection of transmitters where the term important is based on antenna pattern physical environment distances and other wireless propagation fac tors which are well known to one skilled in the art and which are explained below The values of G and P represent gains and power levels respectively for each of M different signal components which may represent individual multipath components or gross signal components from one or more radiating sources and K represents a finite number of constants or functions for each value of i Note that G P and the individual K may be in logarithmic e g dB or absolute values These constants or functions in the above equation may be dependent on distance d between trans mitter and receiver where d may be the straight line or actual reflected diffracted distance of the main signal path between US 6 973 622 B1 21 the serving transmitter and receiver 3 D environment time of observation or observation interval noise power packet sizes coding scheme number of users modulation type interfer
114. smitted Once measured and characterized a single initial time a single component or a string of components within a network may be modeled repeatedly by the invention so that network performance models Wireless performance parameters however are depen dant on many more factors than wired bit error rates For this reason the invention predicts wireless bit error rates based on the environment distance between transmitter and receiver number and types of partitions obstructing the transmission time 3 D position packet size protocol type modulation radio frequency radio frequency bandwidth encoding method error correction coding technique multi path signal strengths and angle of arrival and multipath delay As a result the calculation of the predicted bit error rate is performed using constants or functions to convert from previously measured or known channel and network equipment performance metrics to an expected bit error rate A formulation for predicting the bit error rate frame error rate or packet error rate directly for a data communications channel is shown in equation 4 and is identical to equation 1 BER PER or FER Ci Ad B C 4 M Co D RSSI E RSSI F G G P K i l where BER is bit error rate FER is the frame error rate PER is the packet error rate d is the distance between a trans mitter and a receiver RSSI is the received signal strength intensity which is the power level
115. st bits Packets Self contained lengths of bits with header and or footer hlacks of hits Bits 1 or 0 smallest unit of information Figure 4 Illustration of the data displayed in each node of the Tree View of a data communications network Name and type of network device Specifications Electrical Optical and Electromagnetic specific operating parameters Software Firmware and Hardware version numbers and settings Physical connectors Specifications and setting specific to each connector U S Patent Dec 6 2005 Sheet 3 of 6 US 6 973 622 B1 Figure 5 Method for creating a 3 D site specific model of the environment Create a 3 D site specific model of the environment where the network will be located Layout all network devices in the created environment Add a device to current logical tree layout of network devices known as the Bill of Materials Place the added device in the precise 3 D location in the modeled environment where the actual network device is located Configure the modeled device parameters or download the current settings from the actual device Add another device Modeled environment now ready for data collection performance prediction performance visualization and system optimization U S Patent Dec 6 2005 Sheet 4 of 6 US 6 973 622 B1 Figure 6 Method for optimizing a data communications network using predictions Prediction o
116. system for designing or deploying a communications net work which considers component attributes filed on Aug 4 2000 US 6 973 622 B1 13 An example of some of the information contained in the Layout View hierarchical layout of a data communications network is shown in FIG 4 In the figure a tree structure is used to display all hardware in the network Each node in the tree contains information which is used to track the true physical location logical layout and electrical optical and electromagnetic connections for the data communications network hardware as well as any version numbers and settings of software or firmware running on that network equipment and the known performance parameters of that equipment including the device throughput bandwidth quality of service bit error rate packet error rate frame error rate dropped packet rate packet latency round trip time propagation delay transmission delay processing delay queuing delay network capacity packet jitter band width delay product and handoff delay time The Site View of the invention has a physically accurate three dimensional modeling capability to display all net Work devices in a site specific model of the environment that the network is located in That is the preferred embodiment of the invention allows each modeled hardware and software device to be placed in a three dimensionally accurate man ner and to track attributes of that device relevan
117. t name OPAS32 no date given Company Web Page Agilent www agilent com product name Wizard no date given Company Web Page Camarco www edx com product name SignalPro no date given Company Web Page ComOpt www comopt com product name CellOpt AFP no date given Company Web Page Lucent www bell labs com product name WISE no date given Company Web Page Ericsson www ericsson com product name TEMS Lite no date given Company Web Page Ericsson www ericsson com product name TEMS no date given Company Web Page Marconi www marconi com product name PlaNET no date given Company Web Page Marconi www marconi com product name deciblePlanner no date given Company Web Page Schema www schema com product name Optimizer no date given Company Web Page ScoreBoard www scoreboard com product name ScoreBoard no date given cited by examiner U S Patent Dec 6 2005 Sheet 1 of 6 US 6 973 622 B1 Figure 1 Example transmission of data over a communications network Transmitted Data Received Received Sound f N Communications Network Figure 2 Creation of a digital signal from an analog signal Original Signal U S Patent Dec 6 2005 Sheet 2 of 6 US 6 973 622 B1 Figure 3 Illustration of the difference between bits packets and frames Frames length of bits with a certain pattern or format to indicate first and la
118. t of Agilent Tech nologies has recently created several wireless data mea surement and prediction products SAFCO makes a product called DataPrint which is used to measure various data performance parameters of mobile telephone data networks Their WIZARDS product also supports analysis of the effects of wireless data transmission on the overall capacity and Quality of Service for a wireless telephone network Wireless Valley Communications Inc has created a new concept called SitePlanner which is capable of measuring and tracking the site specific network performance of a data communications network in a physically accurate three dimensional model of an environment SitePlanner uses a software module called LANFielder to measure throughput packet latency and packet error rates for any wired or wireless network connection in any Internet Protocol IP data communications network Additionally SitePlanner allows a full network to be modeled in a physically accurate manner so that precise measurements and performance predictions can be made in a site specific way SitePlanner also allows a logical layout of a network to be stored simultaneously with a physical layout The tool also stores both a logical interconnection and a site specific model of any communications network using a Bill of Materials format In addition to network measurement and asset manage ment tools a good deal of research has taken place in the field of wireless data
119. t one of said one or more components changing settings or configurations of at least one com ponent of said communications network based on instructions sent from said computer or server 38 The method of claim 37 wherein said site specific representation is three dimensional 39 The method of claim 37 wherein said measurement collectors or agents portable or fixed 40 The method of claim 37 further comprising the step of affixing said measurement collectors or agents permanently within said physical space 41 The method of claim 37 wherein said one or more performance metrics predicted in said predicting step are selected from the group consisting of one or more perfor mance metrics are selected from radio signal strength inten sity connectivity network throughput bit error rate frame error rate signal to interference ratio signal to noise ratio frame resolution per second traffic capacity signal strength throughput error rates packet latency packet jitter symbol jitter quality of service security coverage area bandwidth server identification parameters transmitter identification parameters best server locations transmitter location parameters billing information network performance parameters C I C N body loss height above floor height above ground noise figure secure coverage locations propagation loss factors angle of arrival multipath compo nents multipath parameters antenna gains noise level
120. t to data communications networks These key attributes include such items as the hardware type hardware configuration software type software configuration operating system ver sion as well as upper lower and typical specifications for each component These specifications may include impor tant device or network subsystem operating parameters such as throughput bandwidth quality of service bit error rate packet error rate frame error rate dropped packet rate packet latency round trip time propagation delay transmis sion delay processing delay queuing delay network capac ity packet jitter bandwidth delay product and handoff delay time As described below the Site View supercedes prior art described in previous co pending patent applications by Wireless Valley Communications Inc by hereby considering the difficulties and solving data network prediction design and optimization problems for more complicated data com munication networks Specifically this new invention con siders physical site specific modeling techniques and per formance prediction methods and design methods for data network systems both wired and wireless which have performance characteristics that are based on much more complicated physical factors than just radio signal strength interference or multipath alone In particular for data com munication networks many additional factors which relate to particular network equipment or modem desi
121. ted States Patent and Trademark Office UNITED STATES PATENT AND TRADEMARK OFFICE CERTIFICATE OF CORRECTION PATENT NO 6 973 622 B1 Page 1 of 2 APPLICATION NO 09 668145 DATED December 6 2005 INVENTOR S Rappaport et al It is certified that error appears in the above identified patent and that said Letters Patent is hereby corrected as shown below On Page 2 item 56 under OTHER PUBLICATIONS in Column 2 Line 10 delete Panner and insert Planner therefor On Page 2 item 56 under OTHER PUBLICATIONS in Column 2 Line 16 delete Enviroments and insert Environments therefor On Page 2 item 56 under OTHER PUBLICATIONS in Column 2 Line 20 delete Lessions and insert Lessons therefor On Page 2 item 56 under OTHER PUBLICATIONS in Column 2 Line 32 delete Enviroments and insert Environments therefor On Page 2 item 56 under OTHER PUBLICATIONS in Column 2 Line 48 delete Acurracy and insert Accuracy therefor On Page 2 item 56 under OTHER PUBLICATIONS in Column 2 Line 49 delete Enviroments and insert Environments therefor On Page 3 item 56 under OTHER PUBLICATIONS in Column 1 Line 21 delete Wirless and insert Wireless therefor On Page 3 item 56 under OTHER PUBLICATIONS in Column 1 Line 43 delete Wireles and insert Wireless therefor On Page 3 item 56 un
122. ter or server to said at least one component that participates in communicating information over the wireless communications network to update relevant settings of the at least one component based upon the one or more performance metrics for said wireless communications network 91 The system or apparatus of claim 89 wherein the instructions are based upon the one or more performance metrics for said wireless communications network 92 The system or apparatus of claim 89 wherein the at least one component that participates in communicating information over the wireless communications network hav ing settings or configurations changed based on said instructions comprises network equipment and wherein the instructions are provided from the computer or server to the network equipment based upon the one or more performance metrics for said wireless communications network to thereby improve the performance of the wireless communications network 93 A method for analyzing and adjusting a wireless com munications network comprising the steps of generating or using with a computer or server a comput erized model of a wireless communications network within a physical space in which said communications network is deployed said computerized model provid ing a site specific representation of one or more of a floor plan building model terrain characteristics or RF characteristics said computerized model identify ing locations within said p
123. the 3 D envi ronment As with equation 1 equation 4 may consider the distance d as the actual physical distance or as a relative distance referenced to a close in reference Frame error rates packet error rates and packet drop rates can all be calculated from bit error rates or predicted directly 10 15 20 25 30 35 40 45 50 55 60 65 26 using the same method as for a bit error rate as described above or as modeled in equation 4 To perform these calculations the invention uses information stored in the site specific Bill of Materials about the packet size frame size and the protocol in use and uses a site specific propa gation and interference modeling technique such as that utilized in the SitePlanner product by Wireless Valley Com munications Inc In wireless networks modeling the combined effects of all the various sources of errors is extremely difficult Not only does modulation and specific error and source coding tech niques impact the wireless network performance but so does the impact of antennas multipath noise voice over IP or wireless ATM concatenation methods modem design of particular wireless modem makers and the specific RF distribution system used to connect wired and wireless devices The ability to model such varied effects can be done by allowing field measurement of specific in situ network performance as explained earlier By conducting a walk through or a drive test
124. thod for analyzing and adjusting a wireless communications network comprising the steps of generating or using with a computer or server a com puterized model of a wireless communications network within a physical space in which said communications network is deployed said computerized model provid ing a site specific representation of one or more of a floor plan building model terrain characteristics or RF characteristics said computerized model identifying locations within said physical space of one or more components used in said wireless communications net work said computerized model having modeled attributes for at least one of said one or more compo nents downloading or inputting files of measurement data to said computer or server where said measurement data is obtained from said physical space or from said wireless communications network predicting or providing a one or more performance met rics for said wireless communications network based on said measurement data and said modeled attributes for said at least one of said one or more components and changing settings or configurations of at least one com ponent of said wireless communications network based on instructions sent from said computer or server 34 The method of claim 33 wherein said measurement data is obtained from measurement collectors or agents that are either portable or fixed 35 The method of claim 33 further comprising the step of stori
125. throughput measurements as well as theo retically based throughput and delay time tabulations for various wireless LAN configurations The results are given as optimal results however All measurements were per formed in such a way that the wireless channel had the least possible effect on the overall throughput and delay times Therefore the results presented are an upper bound on best possible results and do not extend into a site specific wire less LAN performance prediction technique Hope and Linge have used measurements to calculate the needed parameters for predicting the coverage area of a Wireless LAN network in an outdoor environment by using the Okumura model The researchers have made outdoor measurements with standard IEEE 802 11 wireless LAN modems to calculate the needed parameters of the Okumura model and have presented these results in Hope M and Linge N Determining the Propagation Range of IEEE 802 11 Radio LAN s for Outdoor Applications Local Computer Networks 1999 LCN 99 Conference on 1999 Using these results The coverage area outdoors could be calculated However the results do not allow the user to predict the performance in terms of throughput or latency of a wireless LAN Several patents related to and which allow the present invention are listed below US Pat No 5 491 644 entitled Cell Engineering Tool and Methods filed by L W Pickering et al US Pat No 5 561 841 entitled Method a
126. times of certain network events and may be expressed in time units US 6 973 622 B1 5 of seconds Packet latency is the time required to send a packet from transmitter to receiver while Round Trip Time RTT is the time required for a packet to be sent from transmitter to receiver and for some sort of acknowledge ment to be returned from the receiver to the original trans mitter Propagation delay transmission delay processing delay and queuing delay describe the time required for different portions of a packet transmission to occur The packet latency and round trip time of a network connection is found by summing the propagation delay transmission delay processing delay and queuing delay of either a one way or round trip network connection Propagation delay is the time required for a packet to traverse a physical distance from the transmitter to the receiver Transmission delay is the time required from when the first bit of a packet arrives for the last bit of the same packet to arrive Processing delay refers to the time required to subdivide a data message into the individual packets at the transmitter and to the time required to recreate the full data message from the data packets at the receiver Queuing delay refers to the time spent waiting for shared resources to be freed from use by other transmissions These delay times are all useful for evaluating different aspects of a data communications net work performance Two ot
127. tter and the receiver is divided by the propagation speed 3 10 meters per second of a wireless communications link and then added to the multipath delay introduced by the indirect paths taken from transmitter to receiver as is shown in equation 2 d 2 Tp t P 3s10m s Where T is the propagation delay in seconds d is the distance between the transmitter and the receiver in meters and v is the multipath delay in seconds Predicting the multipath delay is performed using well known raytracing techniques or based on angle of arrival or signal strength values or by making estimated based on the physical model of the 3 D environment Transmission delay is directly calculated from the band width of a connection using the number of bits transmitted To calculate transmission delay the number of transmitted bits is divided by the bandwidth This calculation is identical for wired and wireless channels but must be performed separately for each network device The formula is illus trated in equation 3 US 6 973 622 B1 23 of bits BW 3 Where T is the transmission delay time in seconds of bits are the number of bits in the transmission or packet and BW is the bandwidth of the network link in bits per seconds Processing delay must be calculated for each device separately within a network Processing delay is the time required for a network device to process store and forward the data bits that are
128. ttributes for said at least one of said one or more components and said computer or server can send instructions to said at least one of said one or more components that partici pate in communicating information over said commu nications network which cause settings or configura tions of said at least one of said one or more components that participate in communicating infor mation over said communications network to be changed 110 The system or apparatus of claim 109 wherein the instructions are sent from said computer or server to said one or more components that participate in communicating 10 15 20 25 30 35 40 45 50 55 60 8 information over the wireless communications network to update relevant settings of the one or more components based upon the one or more performance metrics for said wireless communications network 111 The system or apparatus of claim 109 wherein the instructions are based upon the one or more performance metrics for said wireless communications network 112 The system or apparatus of claim 109 wherein the one or more components that participate in communicating information over the wireless communications network hav ing setting or configurations changed based on said instruc tions comprises network equipment and wherein the instructions are provided from the computer or server to the network equipment based upon the one or more performance metrics for said wireless com
129. ty logs into a single set of network statistics This process means the invention requires fewer active measure ment campaigns and more diverse and accurate data for better and more accurate network performance modeling Accurate reliable representations of a data communica tion network require a large number of measured data points Hence the preferred embodiment of the invention collects a large amount of data quickly and easily using various methods as described above The invention does this by providing remote data collection agents which can be installed on data access terminals or embedded in hardware software or firmware within an actual device in the network The remote data collection agents respond to a server program the processing server that controls the measure ments made by the remote agent That is the remote agent can be directed to make a measurement to or from any other remote agent or processing server using any desired proto col traffic type network setting or configuration This process does not require any input from a human user at the remote agent s physical location The agents simply records the data when asked with the correct settings and reports the results back to a server which stores data from all remote agents and other measurement tools The server can generate a variety of detailed reports and use the data to make predictions about expected network performance in future Servers can also function a
130. users on the network and Umax denotes the maximum number of simul taneous users possible Handoff delay times are potential problems in wireless data communication networks A handoff occurs in wireless data networks when a user moves out of range of one access point and into range of another access point In this situation the first access point must pass the responsibility of deliv ering data to the wireless user to the second access point If the two access points are too far apart there will not be enough time for a wireless data network user to be handed off from one access point to another and file transfers can fail The invention predicts where handoffs will occur and the possibility of handoff failures due to incompatible net work settings at two different access points by using site specific time dependent measurements and fitting them into a form of equation 1 4 or 6 Then a table look up method is used to determine prediction models for handoff times as a function of spatial positioning and time of day US 6 973 622 B1 29 The concept of optimization is a key aspect of the invention The preferred invention is highly effective at allowing one skilled in the art to quickly improve the performance of an existing data communications network by comparing measured performance parameters with pre dicted values that are derived and stored in the invention The process of using measurements to improve predictions is calle
131. y the device specifications or as measured simulated or computed by analysis may be used to calculate a predicted queuing delay time Packet latency round trip times and handoff delay times are all based on propagation transmission processing and queuing delay times To accurately predict packet latency and round trip time the propagation transmission process ing and queuing delay times must be summed for all network devices in a particular network link and adjusted using the particular traffic type packet size and protocol type For instance packet latency is the time required for a packet to travel from transmitter to receiver To predict packet latency for a particular link the propagation transmission process ing and queuing delay times must be calculated using the specific network connection traffic type and packet size for the one way transmission of a packet Round trip times are calculated similarly except for the transmission and reception of a packet and the return of the acknowledging packet Thus to predict the round trip time the invention takes into account the original packet size and the size of the acknowledging packet as well as the effects of the specific network connection protocol and traffic type on the propagation transmission processing and queuing delays Handoff delay times are based on the propagation trans mission processing and queuing delays involved in two separate wireless access points

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