Doc.: IEEE 802.22-06/0006r0 Submission January 2006 Gerald Chouinard, CRCSlide 1 TV bands White Spaces and DTV receiver RF front-end performance and protection.

doc.: IEEE 802.22-06/0006r0 Submission January 2006 Gerald Chouinard, CRCSlide 1 TV bands White Spaces and DTV receiver RF front-end performance and protection of Part 74 devices Author: Notice: This document has been prepared to assist IEEE 802.22. It is offered as a basis for discussion and is not binding on the contributing individual(s) or organization(s). The material in this document is subject to change in form and content after further study. The contributor(s) reserve(s) the right to add, amend or withdraw material contained herein. Release: The contributor grants a free, irrevocable license to the IEEE to incorporate material contained in this contribution, and any modifications thereof, in the creation of an IEEE Standards publication; to copyright in the IEEEs name any IEEE Standards publication even though it may include portions of this contribution; and at the IEEEs sole discretion to permit others to reproduce in whole or in part the resulting IEEE Standards publication. The contributor also acknowledges and accepts that this contribution may be made public by IEEE 802.11. Patent Policy and Procedures: The contributor is familiar with the IEEE 802 Patent Policy and Procedures, including the statement "IEEE standards may include the known use of patent(s), including patent applications, provided the IEEE receives assurance from the patent holder or applicant with respect to patents essential for compliance with both mandatory and optional portions of the standard." Early disclosure to the Working Group of patent information that might be relevant to the standard is essential to reduce the possibility for delays in the development process and increase the likelihood that the draft publication will be approved for publication. Please notify the Chair Carl R. Stevenson as early as possible, in written or electronic form, if patented technology (or technology under patent application) might be incorporated into a draft standard being developed within the IEEE 802.11 Working Group. If you have questions, contact the IEEE Patent Committee Administrator at.http://standards.ieee.org/guides/bylaws/sb-bylaws.pdfCarl R. Stevensonpatcom@ieee.org Abstract This contribution summarizes graphically the various constraints expected from the operation of WRAN systems in the TV UHF band to avoid interference to the incumbent services (DTV and Part 74 devices). The reasons for these constraints are clarified in view of identifying key trade-offs and mitigation techniques that will allow enough White Spaces in the UHF TV band for adequate operation of WRAN systems.

doc.: IEEE 802.22-06/0006r0 Submission January 2006 Gerald Chouinard, CRCSlide 2 Outline DTV and WRAN systems characteristics … and critical interference case WRAN Out-of-band emission requirements Maximum WRAN CPE transmit power DTV receiver RF performance models and EIRP profile Intersection of EIRP profiles for multiple DTV channels Impact of not considering polarization discrimination between WRAN CPEs and DTV receivers Protection of Part 74 wireless microphones Conclusions

doc.: IEEE 802.22-06/0006r0 Submission January 2006 Gerald Chouinard, CRCSlide 3 Digital Television Broadcasting (DTV) Parameters Frequency range: VHF/UHF TV-bands Channel bandwidth: 6 MHz TV transmitter: –up to 1 Megawatt ERP –typical coverage: 70 km –RF Mask: Min. distance from DTV TX: –1st adj. channel: 25.8 km –Alternate channels: 97 m … to meet Part 15.209a level DTV Receiving installation –antenna gain: 10 dBd, Front-to-Back: 16 dB –antenna height: 10 m –cable loss: 4 dB –Noise Figure: 7 dB –minimum required field strength: 41 dB(uV/m)

doc.: IEEE 802.22-06/0006r0 Submission January 2006 Gerald Chouinard, CRCSlide 4 Wireless Regional Area Networks (WRAN-802.22) Parameters Frequency range: VHF/UHF TV-bands Channel bandwidth: 6/7/8 MHz Network topology: –point-to-multipoint –master/slave relationship between base station and user terminals User terminal - Customer Premise Equipment (CPE): –antenna gain: 10 dBi directional, Front-to-Back: 16 dB –antenna height: 10 m –vertical polarization (14 dB cross-pol with horizontal DTV) –max. EIRP: 4 Watts (according to FCC NPRM 04-186) Base station: –antenna gain: 12 dB omnidirectional –antenna height: 75 m –max EIRP: 100 Watts –radius of coverage: 31 km

doc.: IEEE 802.22-06/0006r0 Submission January 2006 Gerald Chouinard, CRCSlide 5 Critical interference case Noise limited contour 41 dB(uV/m) Equivalent distance for 100 Watt base station: 50 m ! … 75 m antenna height, antenna vertical pattern !!

doc.: IEEE 802.22-06/0006r0 Submission January 2006 Gerald Chouinard, CRCSlide 7 Out-of-Band emission limit for WRAN devices 4 Watts To limit DTV receiver desensitization to 1 dB at the noise-limited contour (41 dB uV/m), the Out-of-Band (OOB) field strength generated at 3 m in a 120 kHz bandwidth has to be kept below 13.4 dB(uV/m), that is 4.8 uV/m, 32.6 dB lower than the Part 15.209a limit. Part 15.209a 101 dB 46 32.6 dB 13.4 4.8 uV/m 200 uV/m

doc.: IEEE 802.22-06/0006r0 Submission January 2006 Gerald Chouinard, CRCSlide 8 Out-of-Band emission limit for WRAN devices 4 Watts If 14 dB polarization discrimination can be relied upon because of vertically polarized WRAN operation, the OOB emission level can be raised at 27.4 dB(uV/m), 18.6 dB lower than Part 15.209a limit. This corresponds to 87 dB rejection for a 4 Watt EIRP transmitter. Part 15.209a 101 dB 46 32.6 87 dB 27.4 13.4 4.8 uV/m 200 uV/m 18.6 dB

doc.: IEEE 802.22-06/0006r0 Submission January 2006 Gerald Chouinard, CRCSlide 10 Allowable WRAN transmit power in the UHF TV band To avoid saturation of the DTV receiver (i.e., <-8 dBm) for 10 m antenna separation and cross-polar operation, the Customer Premise Equipment (CPE) can transmit up to 41 Watts EIRP.

doc.: IEEE 802.22-06/0006r0 Submission January 2006 Gerald Chouinard, CRCSlide 11 Allowable WRAN transmit power in the UHF TV band The FCC proposes in its NPRM 04-186 to limit the transmission level to 4 Watts EIRP. The spectrum White Space that can be used by WRAN is shown as the grey area (assuming no broadcast station is in operation).

doc.: IEEE 802.22-06/0006r0 Submission January 2006 Gerald Chouinard, CRCSlide 12 Allowable WRAN transmit power in the UHF TV band If there is a TV station in the area and the WRAN terminal is inside its noise- limited contour (equivalent of Grade B contour for NTSC), then the channel occupied by this TV station cannot be used for WRAN operation.

doc.: IEEE 802.22-06/0006r0 Submission January 2006 Gerald Chouinard, CRCSlide 13 Allowable WRAN transmit power in the UHF TV band In fact, because of the limited performance of the DTV receiver RF front-end, the White Space available to WRAN is further reduced.

doc.: IEEE 802.22-06/0006r0 Submission January 2006 Gerald Chouinard, CRCSlide 15 DTV Receiver RF performance -8 dBm -8 dBm, 41 Watts EIRP N+1

doc.: IEEE 802.22-06/0006r0 Submission January 2006 Gerald Chouinard, CRCSlide 16 Allowable WRAN transmit power in the UHF TV band To avoid saturation of the DTV receiver (i.e., <-8 dBm) for 10 m antenna separation and cross-polar operation, the Customer Premise Equipment (CPE) can transmit up to 41 Watts EIRP.

doc.: IEEE 802.22-06/0006r0 Submission January 2006 Gerald Chouinard, CRCSlide 17 DTV Receiver RF performance -8 dBm 4 Watts EIRP, NPRM 04-186 N+1

doc.: IEEE 802.22-06/0006r0 Submission January 2006 Gerald Chouinard, CRCSlide 18 Allowable WRAN transmit power in the UHF TV band The FCC proposes in its NPRM 04-186 to limit the transmission level to 4 Watts EIRP. The spectrum White Space that can be used by WRAN is shown as the grey area (assuming no broadcast station is in operation).

doc.: IEEE 802.22-06/0006r0 Submission January 2006 Gerald Chouinard, CRCSlide 19 Allowable WRAN transmit power in the UHF TV band If there is a TV station in the area and the WRAN terminal is inside its noise- limited contour, then the channel occupied by this TV station and the first adjacent channels cannot be used by WRAN according to NPRM 04-186 (in fact EIRP <-27 dBm).

doc.: IEEE 802.22-06/0006r0 Submission January 2006 Gerald Chouinard, CRCSlide 20 DTV Receiver RF performance -8 dBm Saturation model for extrapolation from ATSC A-74 N+1

doc.: IEEE 802.22-06/0006r0 Submission January 2006 Gerald Chouinard, CRCSlide 21 Allowable WRAN transmit power in the UHF TV band Impact of the DTV receiver performance at the noise-limited contour based on the saturation model for extrapolation of the ATSC A-74 D/U values from the weak desired signal level. (14 dB cross-polarization discrimination)

doc.: IEEE 802.22-06/0006r0 Submission January 2006 Gerald Chouinard, CRCSlide 22 DTV Receiver RF performance -8 dBm Linear extrapolation from ATSC A-74 N+1

doc.: IEEE 802.22-06/0006r0 Submission January 2006 Gerald Chouinard, CRCSlide 23 Allowable WRAN transmit power in the UHF TV band Impact of the DTV receiver performance at the noise-limited contour based on a linear extrapolation of the ATSC A-74 D/U values from the weak desired signal level. (14 dB cross-polarization discrimination)

doc.: IEEE 802.22-06/0006r0 Submission January 2006 Gerald Chouinard, CRCSlide 24 DTV Receiver RF performance -8 dBm Linear interference model for extrapolation from ATSC A-74 N+1

doc.: IEEE 802.22-06/0006r0 Submission January 2006 Gerald Chouinard, CRCSlide 25 Allowable WRAN transmit power in the UHF TV band Impact of the DTV receiver performance at the noise-limited contour based on the more stringent model of linear type of interference. ( 14 dB cross-polarization discrimination)

doc.: IEEE 802.22-06/0006r0 Submission January 2006 Gerald Chouinard, CRCSlide 28 Allowable WRAN transmit power in the UHF TV band Impact of the DTV receiver performance at the noise-limited contour based on a linear extrapolation of the ATSC A-74 D/U values from the weak desired signal level.

doc.: IEEE 802.22-06/0006r0 Submission January 2006 Gerald Chouinard, CRCSlide 29 Allowable WRAN transmit power in the UHF TV band The available White Spaces decrease rapidly with the increase of local TV stations in the area (intersection of all EIRP profiles). (Linear extrapolation of the ATSC A-74 D/U values from the weak desired signal level)

doc.: IEEE 802.22-06/0006r0 Submission January 2006 Gerald Chouinard, CRCSlide 30 Allowable WRAN transmit power in the UHF TV band The available White Spaces decrease rapidly with the increase of local TV stations in the area (intersection of all EIRP profiles). (Linear extrapolation of the ATSC A-74 D/U values from the weak desired signal level)

doc.: IEEE 802.22-06/0006r0 Submission January 2006 Gerald Chouinard, CRCSlide 32 Allowable WRAN transmit power in the UHF TV band Available White Spaces if the DTV receivers only need to be protected for co- channel and 1 st adjacent channels as proposed by the FCC in its NPRM 04-186. (First adjacent channels could be used with EIRP <-27 dBm beyond 25.8 km from DTV transmitter.)

doc.: IEEE 802.22-06/0006r0 Submission January 2006 Gerald Chouinard, CRCSlide 34 Allowable WRAN transmit power in the UHF TV band The available White Spaces decrease rapidly with the increase of local TV stations in the area (intersection of all EIRP profiles). (Linear interference model for extrapolation from weak desired signal level)

doc.: IEEE 802.22-06/0006r0 Submission January 2006 Gerald Chouinard, CRCSlide 36 New TV Receiving antennas Horizontally polarized Circularly polarized New circularly polarized DTV receive antennas expected to give some marginal improvement in multipath are now starting to appear on the market. The use of both polarizations at the DTV receivers will drastically reduce the amount of White-Spaces.

doc.: IEEE 802.22-06/0006r0 Submission January 2006 Gerald Chouinard, CRCSlide 38 Allowable WRAN transmit power in the UHF TV band Impact of the DTV receiver performance at the noise-limited contour based on a linear extrapolation of the ATSC A-74 D/U values from the weak signal level. ( 14 dB cross-polarization discrimination)

doc.: IEEE 802.22-06/0006r0 Submission January 2006 Gerald Chouinard, CRCSlide 39 Allowable License-Exempt transmit power in the UHF TV band Maximum EIRP profile when no polarization discrimination is available (14 dB more stringent) to protect DTV reception at the noise-limited contour based on a linear extrapolation of the ATSC A-74 D/U values from the weak desired signal level.

doc.: IEEE 802.22-06/0006r0 Submission January 2006 Gerald Chouinard, CRCSlide 40 Allowable License-Exempt transmit power in the UHF TV band The available White Spaces decrease very rapidly with the increase of local TV stations in the area (intersection of all EIRP profiles) (Linear extrapolation from weak signal level when no polarization discrimination is available)

doc.: IEEE 802.22-06/0006r0 Submission January 2006 Gerald Chouinard, CRCSlide 42 Allowable WRAN transmit power in the UHF TV band If there is a TV station in the area and the WRAN terminal is inside its noise limited contour, then the channel occupied by this TV station and the first adjacent channels cannot be used by WRAN according to NPRM 04-186 (in fact EIRP <-27 dBm).

doc.: IEEE 802.22-06/0006r0 Submission January 2006 Gerald Chouinard, CRCSlide 43 Allowable WRAN transmit power in the UHF TV band If there is a TV station in the area and the WRAN terminal is inside its noise limited contour, then the channel occupied by this TV station and the first adjacent channels cannot be used by WRAN according to NPRM 04-186.

doc.: IEEE 802.22-06/0006r0 Submission January 2006 Gerald Chouinard, CRCSlide 44 Allowable WRAN transmit power in the UHF TV band White Spaces that would be available if the DTV receivers only needed to be protected for co-channel and 1 st adjacent channels as proposed by the FCC in its NPRM 04-186.

doc.: IEEE 802.22-06/0006r0 Submission January 2006 Gerald Chouinard, CRCSlide 46 Allowable WRAN transmit power in the UHF TV band Impact of the DTV receiver performance at the noise-limited contour based on the more stringent assumption of linear type of interference. ( 14 dB cross-polarization discrimination)

doc.: IEEE 802.22-06/0006r0 Submission January 2006 Gerald Chouinard, CRCSlide 47 Allowable License-Exempt transmit power in the UHF TV band Impact of the DTV receiver performance when no polarization discrimination is available based on the more stringent model of linear interference mechanism in the DTV receiver for extrapolation from the weak signal level.

doc.: IEEE 802.22-06/0006r0 Submission January 2006 Gerald Chouinard, CRCSlide 48 Allowable License-Exempt transmit power in the UHF TV band The available White Spaces decrease very rapidly with the increase of local TV stations in the area (intersection of all EIRP profiles).

doc.: IEEE 802.22-06/0006r0 Submission January 2006 Gerald Chouinard, CRCSlide 49 DTV Receiver RF performance -8 dBm Saturation 4 Watt, NPRM Extrapolation: Saturation model Linear extrapolation Extrapolation: Linear interference model Less White Spaces More White Spaces N+1 … in summary!

doc.: IEEE 802.22-06/0006r0 Submission January 2006 Gerald Chouinard, CRCSlide 51 Protection of Part 74.24 devices Low Power Auxiliary Stations Wireless microphones are licensed secondary users of the TV bands Most microphones use analog modulation (FM), some are digital Bandwidth: 200 kHz (large productions such as Super Bowl may need as many as 200 microphones, i.e., need for some 10 TV channels) Power is limited to 250 mW (24 dBm) in UHF band but microphones usually operate at less than 50 mW to preserve battery life Example: Power: 10 mW, antenna gain: -10 dBi, body absorption: 27 dB, range: 100 m, minimum received power level: -95 dBm Required WRAN CPE out-of-band emission level to protect Part 74 wireless microphones: 6.2 μV/m (15.8 dBμV/m measured at 3 m in 120 kHz) Path loss needed between microphone receiver and L-E devices beyond 1 m (required D/U= 20 dB): –High power WRAN devices (4 Watts): 129 dB –Low-power L-E devices (100 mW): 113 dB

doc.: IEEE 802.22-06/0006r0 Submission January 2006 Gerald Chouinard, CRCSlide 52 Protection of Part 74.24 devices Low Power Auxiliary Stations Mitigation techniques : –Dynamic Frequency Selection (DFS) Sensing, detection, DFS network behavior to avoid hidden nodes Practical sensing threshold: -107 dBm in 200 kHz Maximum sensing distance for: –unfaded microphone: 8.7 km (free space) –faded (27 dB) microphone: 400 m (free space) Interference margin at edge of sensing contour for faded microphone: –High power WRAN devices (4 Watts): -56.1 dB –Low-power L-E devices (100 mW): -40.4 dB –Smart beacon to create a local bubble of protection Transmission of digitally encoded information on TV channels locally used by microphones and encrypted signature (to avoid disallowing L-E operation by hackers) Practical sensing threshold: -120 dBm in 10 kHz Needed transmit beacon power to equate sensing range and interference range: –High power WRAN CPE devices (4 Watts): 16.3 dBm –High power Base Station (100 Watts): 30.2 dBm –Low-power L-E devices (100 mW): 0.3 dBm (contd) (Note: with the use of 42 mW microphones, the beacon power could be kept at 24 mW.)

doc.: IEEE 802.22-06/0006r0 Submission January 2006 Gerald Chouinard, CRCSlide 54 Conclusions There is a tight relationship between the performance of the DTV receiver RF front-end and the amount of White Spaces available in the TV bands for other services such as WRAN: –More measurements are required to characterize the RF performance of typical DTV receivers –Minimum DTV receiver RF performance will need to be established to allow adequate WRAN operation in the TV bands in rural areas WRAN operation needs to rely on cross-polar discrimination between WRAN transmission and DTV reception –vertically polarized antennas for WRAN transmission and horizontally polarized antennas for DTV reception Relative out-of-band rejection at the WRAN CPE will need to be 87 dB or 101 dB depending on polarization discrimination Smart beacons will need to be used to avoid interference to Part 74 wireless microphones

doc.: IEEE 802.22-06/0006r0 Submission January 2006 Gerald Chouinard, CRCSlide 55 References FCC ET Docket 04-186: In the Matter of License-exempt Operation in the TV Broadcast Bands 18-04-0056-00-0000_Comments_ to_TV_Band_NPRM.doc 22-04-0002-12-0000_WRAN_Reference_Model.xls 22-05-0060-02-0000_DTV_RX_Non-linearity_Tests.xls

Doc.: IEEE 802.22-06/0006r0 Submission January 2006 Gerald Chouinard, CRCSlide 1 TV bands White Spaces and DTV receiver RF front-end performance and protection.

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Doc.: IEEE 802.22-06/0006r0 Submission January 2006 Gerald Chouinard, CRCSlide 1 TV bands White Spaces and DTV receiver RF front-end performance and protection.

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