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IEEE 802.22[wardah & mariam]

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IEEE 802.22[wardah & mariam]

  1. 1. 7/5/2014 Electrical Department Institute of Space Technology, Islamabad 1
  2. 2. Presented by: Wardah & Mariam 7/5/2014 2 Electrical Department Institute of Space Technology, Islamabad
  3. 3.  Why IEEE 802.22?  Television WS: A New Hope  Cognitive Radio  IEEE 802.22 Standard  Ongoing Projects  Future Scope  Conclusion 7/5/2014 3 Electrical Department Institute of Space Technology, Islamabad
  4. 4. 7/5/2014 4 Electrical Department Institute of Space Technology, Islamabad
  5. 5. 7/5/2014 5 Electrical Department Institute of Space Technology, Islamabad
  6. 6. Wireless accessibility to underserved areas 7/5/2014 6 Electrical Department Institute of Space Technology, Islamabad
  7. 7.  Spectrum is limited !!!  Underutilized spectrum  Fixed spectrum assignment to primary users  Inefficient usage necessitates the development of dynamic spectrum access techniques  Customer Premise Equipments (unlicensed) are allowed to use the temporarily unused licensed spectrum 7/5/2014 7 Electrical Department Institute of Space Technology, Islamabad
  8. 8.  Vacant frequencies made available for unlicensed use at locations where spectrum is not being used by licensed services.  This spectrum is located in the VHF (54-216 MHz) and UHF (470-698 MHz) frequency bands. 7/5/2014 8 Electrical Department Institute of Space Technology, Islamabad
  9. 9.  “Radio in which communication systems are aware of their environment and internal state and can make decisions about their radio operating behavior based on that information and predefined objectives. The environmental information may or may not include location information related to communication systems” -SDR Forum 7/5/2014 9 Electrical Department Institute of Space Technology, Islamabad
  10. 10.  Ability to sense and gather information  Tx Frequency  BW  Power  Modulation  Customer Premise Equipment identify the best available spectrum 7/5/2014 10 Electrical Department Institute of Space Technology, Islamabad
  11. 11.  Rapidly adapting operational parameters according to the sensed information  Achieving optimal performance  Tx power  Frequency  Modulation scheme 7/5/2014 11 Electrical Department Institute of Space Technology, Islamabad
  12. 12. Sensing •CR enables Customer Premise Equipment to sense available spectrum Selecting •Selects Best available channel Coordination •Coordinates spectrum access with other Customer Premise Equipments Evacuation •Evacuates the channel when PU reclaims the spectrum right 7/5/2014 12 Electrical Department Institute of Space Technology, Islamabad
  13. 13. 7/5/2014 13 Electrical Department Institute of Space Technology, Islamabad
  14. 14.  Aimed at using cognitive radio (CR) techniques to allow:  sharing of geographically unused spectrum allocated to the television broadcast service  on a non-interfering basis  to bring broadband access to low population density areas (rural environments)  The IEEE 802.22, the Working Group on Wireless Regional Area Networks ("WRANs") is developing a wide variety of standards to enable spectrum sharing 7/5/2014 14 Electrical Department Institute of Space Technology, Islamabad
  15. 15. 7/5/2014 15 • Wireless Regional Area Networks (WRANs) - Wireless broadband access (e.g. Rural areas) • Entities: -Base Station -Customer Premise Equipment • Topology- -Point-to-multipoint (P-MP) -Master/Slave relationship • Service Capacity -upto 24 Mbps • Service coverage -upto 100 km Electrical Department Institute of Space Technology, Islamabad
  16. 16.  Base Station  Fixed location  Decides channel availability  Makes final decision (availability of TV channels)  Client Station  Customer Premise Equipment (CPE)  Fixed location  Reports spectrum sensing to Base Station (BS) 7/5/2014 16 Electrical Department Institute of Space Technology, Islamabad
  17. 17.  Specification:  Multiple Access: OFDMA  Frequency Range: 54-862 MHz  Bandwidth: 6 MHz, 7 MHz, 8 MHz  Adaptive Modulation: QPSK, 16-QAM, 64-QAM  Capacity: 24 Mbps  Spectral Efficiency: 4 b/s/Hz  Coding: Convolution Code (mandatory)  Tx/Rx Antenna: BS uses Omni-directional antenna / Customer Premise Equipment uses directional antenna 7/5/2014 17 Electrical Department Institute of Space Technology, Islamabad
  18. 18.  Specification: 1. Superframe and Frame 1. Synchronized timing structure 2. Better incumbent protection 3. Better Self co-existence 4. Frame:  Superframe Preamble  Frame Preamble  Superframe Control Header 2. Cognitive functionality 1. Spectrum Sensing 7/5/2014 18 Electrical Department Institute of Space Technology, Islamabad
  19. 19. 7/5/2014 19 Electrical Department Institute of Space Technology, Islamabad
  20. 20. 7/5/2014 20 Electrical Department Institute of Space Technology, Islamabad
  21. 21.  Fast Sensing: 1 ms  Fine Sensing: 25 ms  Sensing is required:  Analog TV  Digital TV  Wireless microphones  Sensing period : 30 seconds 7/5/2014 21 Electrical Department Institute of Space Technology, Islamabad
  22. 22. 7/5/2014 22 • Sensing mode & Signal type: • Signal Present decision: Check if the signal specified is present in the channel • Confidence Metric: Measure of the confidence that spectrum sensor has in Signal Present Decision • Field Strength Estimate: Estimate of the EM strength of the signal • FS Estimate Accuracy: Measure of the accuracy of FS Estimate Electrical Department Institute of Space Technology, Islamabad
  23. 23.  Comparison of detection statistics with pre- determined threshold 𝛾  Good detector  High detection Probability 𝑃 𝐷  Low false alarm 𝑃𝐹 7/5/2014 23 𝐻0: 𝑦 𝑡 = 𝑛 𝑡 𝐻1: 𝑦 𝑡 = ℎ𝑥 𝑡 + 𝑛 𝑡 T = 1 𝑁 𝑡=1 𝑁 𝑦 𝑡 2 𝑃𝐹 = Pr 𝑇 > 𝛾 𝐻0 𝑃 𝐷 = Pr(𝑇 > 𝛾|𝐻1) Electrical Department Institute of Space Technology, Islamabad
  24. 24. 𝑅 = 7/5/2014 24 α11 ⋯ α 𝑛1 ⋮ ⋱ ⋮ α1𝑛 ⋯ α 𝑛𝑛 T = 𝑇1 𝑇2 𝑇1: 𝑆𝑢𝑚 𝑜𝑓 𝑚𝑎𝑔𝑛𝑖𝑡𝑢𝑑𝑒 𝑜𝑓 𝑎𝑙𝑙 𝑒𝑙𝑒𝑚𝑒𝑛𝑡𝑠 𝑇2: 𝑆𝑢𝑚 𝑜𝑓 𝑚𝑎𝑔𝑛𝑖𝑡𝑢𝑑𝑒 𝑜𝑓 𝑑𝑖𝑎𝑔𝑜𝑛𝑎𝑙 𝑒𝑙𝑒𝑚𝑒𝑛𝑡𝑠 y(n) = 𝑤 𝑛 , 𝑇1 = 𝑇2 𝑥 𝑛 + 𝑤 𝑛 , 𝑇1 ≠ 𝑇2  Test Statistic Electrical Department Institute of Space Technology, Islamabad
  25. 25. 7/5/2014 25 Electrical Department Institute of Space Technology, Islamabad
  26. 26.  Spectrum Sensing issues  Synchronization issues  Multi-dimensional Spectrum awareness  Detection Frequency and Time  Hardware based high speed Signal Processors 7/5/2014 26 Electrical Department Institute of Space Technology, Islamabad
  27. 27.  Smart Grid  Smart Traffic Management  Environment Monitoring  Broadband Service extension  Temporary Broadband Infrastructure  Remote Medical Service 7/5/2014 27 Electrical Department Institute of Space Technology, Islamabad
  28. 28. 7/5/2014 28 Smart Traffic Management Electrical Department Institute of Space Technology, Islamabad
  29. 29.  IEEE 802.22 is required to reuse the fallow TV spectrum without causing any harmful interference to incumbents (i.e., the TV receivers).  Cognitive radio techniques are of primary importance in order to sense and measure the spectrum and detect the presence/absence of incumbent signals.  Base Station and Customer Premise Equipment has Master Slave N/w Architecture  Spectrum sensing is periodically done by BS and CPE  CPE Reports spectrum sensing to Base Station (BS)  BS makes the final decision  CPE vacates the channel if primary  users signal is detected 7/5/2014 29 Electrical Department Institute of Space Technology, Islamabad
  30. 30. 7/5/2014 30 Electrical Department Institute of Space Technology, Islamabad
  31. 31. Research Papers: [1]. Carlos Cordeiro, KiranChallapali, DagnachewBirru, and SaiShankar N “IEEE 802.22: The First Worldwide Wireless Standard based on Cognitive Radios” First IEEE International Symposium on New Frontiers in Dynamic Spectrum Access Networks, 2005. [2]. Carl R. Stevenson, Gerald Chouinard, ZhongdingLei, WendongHu, Stephen J. Shellhammer and Winston Caldwell “IEEE 802.22: The First Cognitive Radio Wireless Regional Area Network Standard” IEEE Communications Magazine, January 2009. [3]. IEEE 802.22 Working Group on Wireless Regional Area Networks, http://www.ieee802.org/22/. [4]. H. Urkowitz, “Energy detection of unknown determin- istic signals,” Proc. of IEEE, pp. 523–531, Apr. 1967. [5]. Beibei Wang and K. J. Ray Liu, “Advances in Cognitive Radio Network: A Survey” IEEE Journal Vol. 5, NO.1, Feburary 2011 7/5/2014 31 Electrical Department Institute of Space Technology, Islamabad

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