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© 2008 AT&T Knowledge Ventures. All rights reserved. AT&T and the AT&T logo are trademarks of AT&T Knowledge Ventures. UHF TV White Space --A New Challenge for Spectrum Managers Annual Meeting, National Spectrum Managers Association Arlington, VA May 20-21, 2008 Paul Henry AT&T Labs – Research Middletown, NJ firstname.lastname@example.org
© 2008 AT&T Knowledge Ventures. All rights reserved. Underutilized Spectrum Can white space spectrum be successfully managed ?
© 2008 AT&T Knowledge Ventures. All rights reserved. UHF TV Whitespace Channel 54 in the Eastern US (graphic courtesy of Shared Spectrum Co. from a contribution to IEEE 802.18 SG1) May 2004: FCC proposes to allow unlicensed use of TV whitespace Primarily UHF ~500-700 MHz (chan 21-51) -- Desirable propagation characteristics Must protect TV and wireless microphone Smart (cognitive) radio may be needed Unlicensed operation Allowed Not allowed Nov 2004: IEEE802.22 formed to explore WRAN (~33 km nominal range) Oct 2006: FCC allows low-power fixed use; regulations TBD Continues inquiry re portable use; regulations 1H08 3Q08 Dec 2007: OFCOM (UK) Report 112 MHz to be allocated for unlicensed use after Digital Switchover (2012) Feb 2009: US DTV transition (2012 in UK)
© 2008 AT&T Knowledge Ventures. All rights reserved. Available Spectrum (after Digital TV transition in Feb 2009) *6 MHz/channel
© 2008 AT&T Knowledge Ventures. All rights reserved. Wireless Residential Multimedia Networking Broadband Access Media & Communications Server White space (cog radio) modem PDA Remote Capability 19Mbps per 6 MHz TV channel Multimedia with QoS (incl HDTV), Internet, VoIP Portability Modest power: ~10mW Technical challenge: protect incumbent users Typ path loss ~75dB
© 2008 AT&T Knowledge Ventures. All rights reserved. Keep white space devices outside of TV service area. Geolocation -- GPS Authoritative database – central control Unreliable indoors Increased device cost Spectrum sensing White space users scan for vacant channels Hidden-node problem What is radius of destruction for white space device? Protecting TV Users TV Service Area Residential white space network
© 2008 AT&T Knowledge Ventures. All rights reserved. Radius of Destruction To avoid interference to DTV: Air path loss > Pt – DTV tolerance – penetration loss + TV antenna gain = +10dBm + 104 – 10 + 8 = 112 dB Propagation loss (Longley-Rice model): 112 dB implies R d ~ 2 km – Faster decay than inverse-square Note: Outdoor WRAN (802.22): 4 watt transmitter implies Rd ~ 15 km! Must inhibit transmission whenever within ~2 km of viewable DTV signal – Can white space device sniff for TV signal and then make reliable decision? TV transmitter White space device DTV receiver sensitivity: -84 dBm DTV Interference tolerance: -104 dBm RdRd
© 2008 AT&T Knowledge Ventures. All rights reserved. Spectrum Sensing --The Hidden Node Problem TV transmitter DTV sensitivity -84dBm White space device Shadow Device sensitivity margin = shadow fading + penetration loss + antenna gain difference Shadow fading in 90% of locations < 15dB* Typical penetration loss ~10dB** Antenna gain difference ~ 8dB* Required device margin ~ 15 + 10 + 8 = 33 dB (~ 90% successful detection) Device sensitivity = -84 dBm -33 dB = -117 dBm Demonstrated device sensitivity: -115 to -120 dBm *R.A.OConnor, IEEE Trans Broadcasting, Sept 2001 **M.A.Sturza, Working Paper #16, New America Foundation, Jan. 2007 DTV spectrum
© 2008 AT&T Knowledge Ventures. All rights reserved. Wireless Microphone Low power (working range < 100m) No standard signature like DTV; therefore very hard to detect Solution – Easily recognized beacon; protective bubble Problems – Abuse of protection – Unlicensed users (e.g. schools, churches); squatters rights WSD Mic Rcvr Protective Bubble Beacon
© 2008 AT&T Knowledge Ventures. All rights reserved. Field of Battle Opposed Cox communications Nat Assn Broadcasters NFL NASCAR In Favor Dell Google Microsoft Philips FCC Docket ET 04-186 Mobility UVerse Radio science lost in political shouting match FCC labs conducting independent evaluation
© 2008 AT&T Knowledge Ventures. All rights reserved. FCC Field Tests Initial tests summer 2007 DTV detection: Philips -115dBm; Microsoft device failed Wireless mic detection (no beacon): Many false positives Technology not good enough for definitive field tests Recent activity Google laboratory: -120dBm sensitivity Ongoing tests: Philips, Microsoft, Motorola, Adaptrum No abatement of political posturing
© 2008 AT&T Knowledge Ventures. All rights reserved. Breaking the Logjam --Motorola and Google Proposals Goal: Get past the squabbles over spectrum sensing Dec. 07: In FCC filing Motorola proposes 2 classes of white space devices – <10mW (e.g. WLAN): spectrum sensing only – >10mW (e.g. 802.22 WRAN): Geolocation with spectrum sensing backup – Minimal public reaction March 08: Google proposes geolocation for all white space operation – Calls press conference WiFi on steroids Gigabit rates – Lots of headlines – Mission Accomplished – Probably consistent with Googles aspirations, but unacceptable to proponents of bluetooth-like applications Intense lobbying continues
© 2008 AT&T Knowledge Ventures. All rights reserved. Takeaways UHF TV white space Opportunity to use sparsely occupied, attractive spectrum Must protect digital TV and wireless microphone Technologies: Spectrum sensing, geolocation, beacon Protection achievable in lab setting; field tests to come Intense political posturing; logjam at FCC DTV transition Feb 2009 less than a year away; stay tuned…..
© 2008 AT&T Knowledge Ventures. All rights reserved. Thank you!
Doc.: IEEE Submission January 2004 Bill Byrnes, Shared Spectrum Co. Frequency Agile Spectrum Access Technologies This Presentation.
Cognitive Radio: Opportunities and Challenges Dr Ying-Chang Liang Senior Scientist & Project Manager Institute for Infocomm Research (I 2 R) Singapore.
Utilizing White Spaces for broadband access Where do we go from here? Fanny Mlinarsky octoScope.
Introduction to TV White Spaces In Ecma International TC48-TG1TC48-TG1 Ecma/TC48-TG1/2009/017.
All Rights Reserved © Alcatel-Lucent 2006, ##### Design Issues for Wireless Networks Across Diverse and Fragmented Spectrum Collaborators: Bell Labs India:
White Spaces Update NSMA Spectrum Management 2012 May 2012 H. Mark Gibson Director, Business Development.
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Using License Exempt Spectrum for Wireless Broadband Ronald Repasi, Deputy Chief Office of Engineering and Technology Regional Educational Workshop On.
Sg-whitespace-09/0019r0 Submission January 2009 Steve Shellhammer, QualcommSlide 1 Impact of FCC R&O on IEEE 802 Date: Authors: Notice: This.
Tutorial on the P PAR for: Recommended Practice for the Installation and Deployment of IEEE Systems Carl R. Stevenson, WK3C Wireless LLC.
ITU-R SG8 Seminar on Tomorrows Technological Innovations Geneva, Switzerland September 9, 2004 Carl R. Stevenson, Agere SystemsSlide 1 Exploring the Feasibility.
Doc.: IEEE /0024r0 Submission FCC Report on Sensing of TV Channels IEEE P Wireless RANs Date: January 2009 Victor TawilSlide.
A View from the FCC’s Office of Engineering & Technology NSMA Spectrum 2008 May 21, 2008 Julius P. Knapp Chief Office of Engineering and Technology Federal.
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Speaker: You-Min Lin Advisor: Dr. Kai-Wei Ke Date: 2011/04/25 Cognitive Radio Networks (CRN) 1.
SSC Page 1 Frequency Agile Spectrum Access Technologies Presentation to FCC Workshop on Cognitive Radios May 19, 2003 Mark McHenry Shared Spectrum Company.
White Space Spectrum Presented by: Chris Whiteley, Director of Business Development xG Technology, Inc. Jan. 22, 2010 Potential to Deliver Broadband Wireless.
Tan Zhang, Ning Leng, Suman Banerjee University of Wisconsin Madison
Office of Engineering and Technology Agenda Meeting January 15, 2004.
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