Wireless network operation in the TV Bands May 10-14, 2004 Wireless network operation in the TV Bands Barry O’Mahony barry.omahony@intel.com IEEE 802 wireless interim meeting Garden Grove, CA 10-14 May 2004 Barry (Intel)

Overview Background Status TV Band Incumbents May 10-14, 2004 Overview Background Status TV Band Incumbents Vacant Channel Device (VCD) operation Summary References Barry (Intel)

May 10-14, 2004 Background FCC 12/2002 released Notice Of Inquiry (NOI) concerning “Additional Spectrum for Unlicensed Devices Below 900 MHz and in the 3 GHz Band” “below 900 MHz spectrum” in question focused on spectrum where TV broadcasters are primary users. VHF-L ch. 2-6 (54-72, 76-88 MHz); VHF-H ch. 7-13 (174-216 MHz); UHF ch. 14-51 (470-698 MHz) Not channels 52; this spectrum is being re-allocated to non-TV use Discussed potential of Part 15 modifications that would allow unlicensed devices to use spectrum in locations where it would not cause interference to licensed operations, via cognitive technologies Intel submitted Comments [refs. 4, 6] and Reply Comments [ref. 5] in support Authors Waltho, Schiffer, Chartier, Pitsch Barry (Intel)

May 10-14, 2004 Status 14 May 2004 FCC Announces Notice of Proposed Rule Making (NPRM) on unlicensed operation in the TV bands Two categories of unlicensed devices proposed Lower-power “personal/portable” devices e.g.; “Wi-Fi like cards in laptop computers” Higher-power “fixed/access” devices Used to provide “a commercial service such as wireless broadband internet access” Barry (Intel)

TV Band incumbents Part 73 – Primary Users Part 74 – Secondary Users May 10-14, 2004 TV Band incumbents Part 73 – Primary Users Full Service TV Serve ~210 DMA’s Class A Low Power Primary Users Part 74 – Secondary Users Low-Power TV LPTV stations – low power “opportunistic” users Translators & Boosters TV broadcast auxiliary stations – UHF Professional wireless microphones Other Parts 90 & 20 Mobile Radio Service One or two TV channels in 13 DMA’s in Ch. 14-20 range (3 in LAX) Part 15 remote controls, >70 MHz “Legacy” medical telemetry transmitters, Channels 7-46 Channel 37 reserved for Radio Astronomy Barry (Intel)

45KW- VHF-L 160KW- VHF-H 1MW - UHF May 10-14, 2004 TV Broadcast Stations Type Full Service LPTV / Translators / Boosters Class A Spectrum Usage Primary Secondary Year enacted Analog 1941 Digital 1998 1982 2000 Maximum Radiated Power 316KW – VHF 5MW – UHF 45KW- VHF-L 160KW- VHF-H 1MW - UHF 3KW – VHF 150KW - UHF 300W – VHF 15KW - UHF Range (miles) 60-80 15-20 # (approx.) 1500 - NTSC 1200-DTV 2,200 – LPTV 4,700 - Translators 600 Barry (Intel)

TV Broadcast Coverage Predicted service contours Analog – Grade B May 10-14, 2004 TV Broadcast Coverage Predicted service contours Analog – Grade B Acceptable Picture Quality “Slightly annoying” on ITU-R subjective scale Digital – Service Contour Threshold of Visibility (ToV) Segment Error Rate (SEV) 1.9  10-4 15 dB SNR Within these contours, coverage predicted using Longley-Rice propagation model Stations protected within coverage area Interference protection - from other transmitters* Copyright protection - SHVIA *Class A stations protected at Grade A signal level Barry (Intel)

Field Strengths @ Contour Edge May 10-14, 2004 Field Strengths @ Contour Edge Analog Channels Field Strength, dBμ/m Grade A Grade B VHF-L 68 47 VHF-H 71 56 UHF (mid-band) 74 64 Digital Channels Field Strength, dBμ/m VHF-L 28 VHF-H 36 UHF (mid-band) 41 Field strengths predicted using F(50,50) [analog] and F(50,90) [digital] curves from Part 73.699 Barry (Intel)

FCC DTV Planning Factors May 10-14, 2004 FCC DTV Planning Factors Planning factor Symbol VHF-L VHF-H UHF Mean freq., MHz F 69 194 615 Dipole factor (dBm-dBu) Kd -111.8 -120.8 -130.8 Dipole factor adjustment Ka -20  log(615/f) Thermal noise, dBm Nt -106.2 Antenna gain, dBd G 4 6 10 Rcv. Antenna F/B ratio* Analog DTV 12 14 Downlead loss, dB L 1 2 Noise figure, dB Ns 7 SNR, dB C/N 15 Used to compute Service area field strength and interference protection requirements *used for interference calculations Barry (Intel)

Interference Protection May 10-14, 2004 Interference Protection Channel offset D/U Ratio, dB Analog into analog Digital into analog Analog into DTV DTV into DTV Lower adjacent -3 -14 -48 -28 Co-channel +28 +34 +2→+21* +15→+23* Upper adjacent -13 -17 -49 -26 TV-to-TV co-channel and adjacent channel D/U Ratios: *Higher ratio required at edge of service area … Leads to separation distance requirements: Channel offset Separation, Km (Zone II) Analog / analog Digital / analog DTV / DTV Adjacent >95.7 - VHF >87.7 - UHF <11& >125 – VHF <12& >106 – UHF <23 & >110 – VHF <24 & >110 – UHF Co-channel >304.9 - VHF >280.8 - UHF >273.6 - VHF >244.6 - UHF >273.6 - VHF >223.7 - UHF Note co-located adjacent channel operation permitted for DTV Barry (Intel)

Interference Protection [2] May 10-14, 2004 Interference Protection [2] Presumed TV receiver limitations imposed additional requirements in UHF band – “taboo” channels: Channel Offset D/U Ratio Interference mechanism Analog into analog DTV into analog N-8 -32 IF Beat N-7 -30 -35 “ N-4  -34 Intermod N-3 -33 N-2 -26 -24 N+2 -29 -28 N+3 N+4 -23 -25 Half IF & Intermod N+7 -43 N+8 -41 N+14 Aural Image N+15 -9 -31 Visual Image Tuned Circuit RF Amp IF Strip L.O. F + 45.75 MHz AGC Tuning Voltage “Classic” TV front end Leads to separation requirements for these channels as well Barry (Intel)

Broadcast TV Landscape May 10-14, 2004 Broadcast TV Landscape These separation criteria lead to significant white space in most locations Sample Portland, OR UHF TV Spectrum (as of Jan. ’01) Barry (Intel)

Vacant Channel Devices (VCD) May 10-14, 2004 Vacant Channel Devices (VCD) VCDs must operate without causing interference to co-channel and adjacent channel (primarily 1st adjacent) TV; While at the same time accept interference from adjacent channel TV transmitters Barry (Intel)

Topology of Concern May 10-14, 2004 TV Receiver A Co-channel Protection area TV Transmitter A “Co-channel” VCD’s Protected Area A TV Receiver B Adjacent channel Protection area TV Transmitter B “Adjacent Channel” Protected Area B Barry (Intel)

Incumbent TV detection May 10-14, 2004 Incumbent TV detection Analog (NTSC) Visual Carrier 1.25 MHz from band edge Aural Carrier 4.5 MHz from visual carrier Chroma subcarrier ~3.58 MHz from visual carrier (precisely 227.5  H scan rate) Digital (ATSC) 8-level Vestigial SideBand (8VSB) modulation Pilot signal 11.3 dB below full-band power 310 KHz from band edge; or ~ 332 KHz (precisely 323  H scan rate above lower visual carrier) when co-located with lower-adjacent analog channel Barry (Intel)

Incumbent TV detection [2] May 10-14, 2004 Incumbent TV detection [2] Analog SNR at Grade B contour: 34 dB Digital SNR at service contour: 15 dB Characteristics of both analog and digital signals should allow reliable detection significantly below level usable for TV reception e.g., example in (ref. 5), 6 KHz filter on carrier(s) improves sensitivity by 30 dB Barry (Intel)

Interference Protection May 10-14, 2004 Interference Protection For wideband unlicensed signals, can use D/U ratios as for DTV For narrowband signals (≤25 KHz), may use FCC regs. for Wireless Communications Service (WCS) in the Ch. 52-67 band (Part 27.60) Channel offset D/U Ratio, dB Narrow into analog Wide into analog Narrow into DTV Wide into DTV Lower adjacent -14 -23 -28 Co-channel +40 +34 +17 +15→+23 Upper adjacent -17 -26 Barry (Intel)

May 10-14, 2004 VCD Transmit Power Assuming a vacant channel, VCD TX will depend on D/U ratio for adjacent channels “worst-case” is separation distance from an adjacent channel receiver located at Grade B contour edge (ref. 4): Assumes free-space propagation Higher powers possible in locations where adjacent channel signal is strong Barry (Intel)

Interference from Adjacent TV May 10-14, 2004 Interference from Adjacent TV FCC adjacent channel emissions -60 to -88 dB for NTSC, -60 to -78 dB for DTV stations In 500 KHz BW, relative to peak channel power Will interfere with VCD signal e.g.; case for UHF Tx, EIRP = 1MW, 20 dB VCD SNR desired (40 Mbps capacity) (ref. 4): Barry (Intel)

May 10-14, 2004 Summary Fixed-power VCD operation will allow WLAN-like ranges and bitrates Adaptive tx control when adjacent signals are stronger will allow longer ranges/higher speeds High power levels for WMAN-like operation require enhanced incumbent profile detection Barry (Intel)

References CFR Title 47, Parts 20, 27, 73, 74, 90 May 10-14, 2004 References CFR Title 47, Parts 20, 27, 73, 74, 90 FCC OET Bulletin No. 69, Longley-Rice Methodology for Evaluating TV Coverage and Interference, http://www.fcc.gov/Bureaus/Engineering_Technology/Documents/bulletins/oet69/oet69.pdf FCC Notice Of Inquiry, Additional Spectrum for Unlicensed Devices Below 900 Mhz and in the 3 GHz Band, ET Docket No. 02-380, http://gullfoss2.fcc.gov/prod/ecfs/retrieve.cgi?native_or_pdf=pdf&id_document=6513404215 Comments of Intel Corporation, http://gullfoss2.fcc.gov/prod/ecfs/retrieve.cgi?native_or_pdf=pdf&id_document=6513982734 Reply Comment of Intel Corporation, http://gullfoss2.fcc.gov/prod/ecfs/retrieve.cgi?native_or_pdf=pdf&id_document=6514088965 Comments of Intel Corporation, http://gullfoss2.fcc.gov/prod/ecfs/retrieve.cgi?native_or_pdf=pdf&id_document=6514782022 Barry (Intel)