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© British Telecommunications plc Cognitive Radio Research at BT Dr Maziar Nekovee BT Innovate and Design & University College London

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Presentation on theme: "© British Telecommunications plc Cognitive Radio Research at BT Dr Maziar Nekovee BT Innovate and Design & University College London"— Presentation transcript:

1 © British Telecommunications plc Cognitive Radio Research at BT Dr Maziar Nekovee BT Innovate and Design & University College London maziar.nekovee@bt.com

2 © British Telecommunications plc Demand for mobile wireless communications But also Home networks (e.g. HDTV streaming) Smart metering RFID Machine-to-machine (e.g. intelligent transport systems) Developing countries

3 © British Telecommunications plc Key resource: Radio Spectrum UK Industry paid over 20 billion pound for 140 MHz 3G spectrum

4 © British Telecommunications plc Who “owns” all the spectrum and why is it scarce?

5 © British Telecommunications plc Solution 1: spectrum trading (Cave’s Report) Command & Control Zone Ofcom manages it Market Forces Zone Companies manage it Licence-exempt Zone Nobody manages it Approach that was adopted for about 94% of the spectrum Approach advocated by Cave and implemented by trading and liberalisation Approach currently adopted for 6% of spectrum, some argue for radical increase 20046%7%2010 20040%72%2010 200494%21%2010 Source: William Webb, Ofcom

6 © British Telecommunications plc Solution 2: Opportunistic Spectrum Access Source: Yucek and Arsalan, IEEE Comm. Surveys and Tutorial, 2009

7 © British Telecommunications plc Cognitive Radio Enabling technology for OSA, …and much more Cognitive Cycle Joseph Mitola III

8 © British Telecommunications plc Cognitive Access to TV White Spaces: Spectrum Opportunity and Technology Challenges

9 © British Telecommunications plc What are TV White Spaces?  Cognitive radios can use channels {A1,A2,A3,B1,B2,B3,C1,C2,C3  Provided they do not cause harmful interference to TV receivers within the coverage areas of A, B, C, and to wireless microphones (PMSE)

10 © British Telecommunications plc How much TVWS is there? Source: Ofcom Consultation on Cognitive Access, 9 February 2009  256 MHz interleaved spectrum (total UK 3G spectrum 140 MHz!)  US auction of cleared TV spectrum raised $25 billion in 2008  However, the availability varies strongly with location and trasmit power, but how exactly?

11 © British Telecommunications plc Quantifying TVWS availability in the UK cognitive device Total number of available channels for CR at location r

12 © British Telecommunications plc Regional variations in TVWS spectrum for cognitive access 8 MHz/channels London Cambridge Cardiff Ipswich Edinburgh Southampton Liverpool Source: Nekovee, Proc. IEEE ICC 2009 Bristol Manchester Swansea Leeds Plymouth Oxford Birmingham Glasgow Thuriso Newcastle Brighton 0n average 150 MHz at any location in the UK

13 © British Telecommunications plc Source: Nekovee, Proc. IEEE ICC 2009

14 © British Telecommunications plc Spectrum identification/interference avoidance Single-device detection –Sensing below thermal noise levels! Cooperative detection –Certification difficult –Spectrum sensor nets –Security issues Spectrum database –Favoured by FCC and Ofcom Microsoft, Google and BT –Wireless microphones are tricky –Requires location-awareness

15 © British Telecommunications plc Detecting DVBT signals below noise levels Energy detection Feature detection (increased complexity) –Autocorrelation –Cyclic prefix –Eigen value detection Source: Wang, Pervez, Nekovee, 2009

16 © British Telecommunications plc Potential applications: system-wide studies Home Networks Rural Broadband Mobile Broadband without 3G/4G? IEEE 802.22 standard Living Room Bedroom 1Bedroom 2 Kitchen Den Deck/Patio Broadband Internet Connection CogNea Standard

17 © British Telecommunications plc Proposition A: Home Networks TVWS Set-top Box HDTV data via TVWS HDTV mobile device BT Homehub network BT TVWS database 1.Queries TVWS database 2. Provides available TVWS channels and power levels device data via WiFi Architecture –Point-to-Multipoint –Master-Slave CogNea Standard (Philips, Samsung, BT)

18 © British Telecommunications plc Interference study, scenario modeled Square kilometre of central London 40% houses (out of total 5000) selected with home hubs Same service requirement 2 Mb/s, 6 Mb/s @ 12m range With three interference loadings –Video-streaming only traffic profile – worst case scenario –Traffic profile mix of voice, video, data corresponding to 2 Mb/s –Traffic profile mix of voice, video, data corresponding to 6 Mb/s TVWS Spectrum in Central London available channels Source: Kawade, Nekovee, IEEE DySPAN 2010 (submitted)

19 © British Telecommunications plc Technical assumptions for comparing various options ParametersLTEHSPAWiFi@2.4 GHz 11nWiFi@5.4 GHz 11n 802.11 TVWS Centre Frequency 2.6 GHz2.1 GHz2.4 GHz5.4, 5.8 GHz400-862 MHz EIRP 20d dBm14 dBm20 dBm23, 30 dBm3, 9 dBm Channel Bandwidth 20 MHz5 MHz20 MHz 20 (40 MHz optional)8 MHz Antenna scheme None 2x1 STBC None Wireless Interface OFDM D/LCDMAOFDM Duplex FDD TDD Modulation & Coding schemes 1/2, 3/4 QPSK 1/2, 3/4 16-QAM 1/2, 2/3, 3/4, 5/6, 1/1 64- QAM 1/2, 3/4 QPSK 1/2, 3/4, 5/6, 1/1 16- QAM 5/6, 1/1 64-QAM 1/2, 3/4 BPSK 1/2, 3/4 QPSK 1/2 16 QAM 2/3, 3/4 64 QAM Other assumptions: MAC layer overheads were assumed to be approximately 30% of the raw wireless link rate No antenna scheme considered for TVWS band due to λ/2 restriction however CogNeA (Philips, Samsung, Texas, HP) propose some antenna scheme/MIMO for laptops in higher UHF (in the other end of TVWS spectrum)

20 © British Telecommunications plc Outage clients (< 1 Mb/s) : 3% Service requirement 2 Mb/s: 97% Service requirement 6 Mb/s :50% TVWS performance results (3/3) Source: Kawade, Nekovee, IEEE DySPAN 2010 (submitted)

21 © British Telecommunications plc Nomadic/Mobile broadband with BT FON Cooperative scheme for sharing home WiFi Over 1 million BT FONs, and growing TV transmitter

22 © British Telecommunications plc Cognitive Radio: A longer term view

23 © British Telecommunications plc A quasi-continuum spectrum CR2CR1CR3 Now Future Dynamic spectrum pooling based on user requirements, availability, and price An elementary sub-channel Source: Nekovee, Proc. CrownCom 2008

24 © British Telecommunications plc Spectrum portfolio Choose a spectrum band Click on the item below to connect to BT Network via one of the available spectrum bands TV White Spaces free of charge (cognitive only) 3G Spectrum Vodafone £0.0012 per second (licensed or cognitive only) Radar spectrum ISM bands free of charge (best effort) 2G Spectrum Orange £0.0005 per second (licensed or cognitive only) 3G Spectrum 3 £0.0014 per second (licensed or cognitive only) Refresh spectrum list Setup an automated spectrum manager Learn about cognitive spectrum access Change the order of preferred spectrum Change advanced settings Cognitive Spectrum Access

25 © British Telecommunications plc Our research interests/activities Technologies and models System-wide issues: multi-user access (etiquette), capacity and coverage, QoS and mobility Agile modulation (NC-OFDM) and channel bundling techniques Cognitive radio testbed and trials Sensing, antenna arrays and MIMO for cognitive access Cognitive radio +optical communication? Spectrum micro auctions Spectrum databases Application Scenarios Future home networks Mobile/nomadic broadband Smart metering Cognitive Femtocells Cognitive radio in vehicles Collaborations 2 large FP7 projects (starts Jan 2010) Microsoft, Google, BBC, CogNea Scottish Universities Open to exploring new ones!

26 © British Telecommunications plc In press


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