Slide 1

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. Slide 2 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 Slide 3 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) Slide 4 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 Slide 5 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 !! Slide 6 doc.: IEEE 802.22-06/0006r0 Submission January 2006 Gerald Chouinard, CRCSlide 6 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 Slide 7 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 Slide 8 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 Slide 9 doc.: IEEE 802.22-06/0006r0 Submission January 2006 Gerald Chouinard, CRCSlide 9 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 Slide 10 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.,