1. doc.: IEEE 802.22-13/0010r0 Submission January 2013 Gerald ChouinardSlide 1 Overview of the 802.22.1 Beacon Standard IEEE 802.22 Wireless RANs Date: 2013-01-15 Authors: 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 IEEE’s name any IEEE Standards publication even though it may include portions of this contribution; and at the IEEE’s 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 802.22. Patent Policy and Procedures: The contributor is familiar with the IEEE 802 Patent Policy and Procedures http://standards.ieee.org/guides/bylaws/sb-bylaws.pdf 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 Chairhttp://standards.ieee.org/guides/bylaws/sb-bylaws.pdf Dr. Apurva ModyDr. Apurva Mody 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 802.22 Working Group. If you have questions, contact the IEEE Patent Committee Administrator at patcom@iee.org.patcom@iee.org >

2. doc.: IEEE 802.22-13/0010r0 Submission January 2013 Gerald ChouinardSlide 2 Wireless microphone beacon sensing Wireless microphones have a large signal level variability because of the way they operate Sensing wireless microphones would result in unreliable detection of their operation 802.22 developed a standard for the beacon to reliably signal the presence of wireless microphones: –Constant transmission power (250 mW at UHF) –Intelligent ad-hoc networking among beacons that results in only one active local beacon per TV channel –Beacon antenna normally located above the wireless microphone receivers (e.g., on top of ENG trucks) to maximize the bubble of protection from WRAN operation

3. doc.: IEEE 802.22-13/0010r0 Submission January 2013 Gerald ChouinardSlide 3 802.22.1 Beacon Design Inter-beacon networking period I-channel Q-channel 3.33 ms 98 ms - Source address - Location - Subchannel map - Signature - Certificate 101 ms N = 30 Sync burst DQPSK 8-chip

4. doc.: IEEE 802.22-13/0010r0 Submission January 2013 Gerald ChouinardSlide 4 802.22.1 Beacon Design (cont’d)

5. doc.: IEEE 802.22-13/0010r0 Submission January 2013 Gerald ChouinardSlide 5 802.22.1 Beacon Design (cont’d)

6. doc.: IEEE 802.22-13/0010r0 Submission January 2013 Gerald ChouinardSlide 6 802.22.1 Beacon Design (cont’d)

7. doc.: IEEE 802.22-13/0010r0 Submission January 2013 Gerald ChouinardSlide 7 Detection of the 802.22.1 beacon 0.8 ms 5.1 ms 28 ms 71 ms 98 ms < 0.5 ms

8. doc.: IEEE 802.22-13/0010r0 Submission January 2013 Gerald ChouinardSlide 8 Sensitivity of the 802.22.1 wireless microphone beacon FCC requirement

9. doc.: IEEE 802.22-13/0010r0 Submission January 2013 Gerald ChouinardSlide 9 Wireless microphone protection Power= 10 mW Ant. gain= -10 dBi Extra fade= 27 dB 100 m RX Power= -95 dBm D/U= 20 dB Reciprocal RF path Transmit: EIRP= 4 Watts Sensing: Ant. gain= 0 dBi Cable loss= 4 dB Noise Figure= 6 dB Threshold= -114 dBm Wireless microphone beacon Power= 250 mW Ant. gain= 2 dBi 4 km QPSK, rate:1/2 8:1 spread spectrum BW= 77 kHz Requirement for protection: Beacon sensing distance > 4 W interference range Differential: Beacon Microphone Power: 10 log(250/10)= 14 dB Antennas: 2-(-10)= 12 dB Extra fade= 27 dB Total= 53 dB Beacon results in 53 dB higher sensitivity!

10. doc.: IEEE 802.22-13/0010r0 Submission January 2013 Gerald ChouinardSlide 10 Practical limits to RF sensing 802.22 Sensing threshold: -116 dBm Differential between beacon and microphone: 53 dB Required threshold to sense wireless microphone at the interference range: -116 - 53 +6= -163 dBm (note that the 6 dB covering for frequency selective fading no longer applies when the actual microphone is detected.) For 100 mW portable devices, the interference range would be reduced: -163 + 10*log(4/0.1)= -147 dBm Since unlike in the case of DTV sensing, the azimuth of the W-microphone signal is the same as the signal transmitted, the same directional antenna could be used: -163+11 dBi = -152 dBm

11. doc.: IEEE 802.22-13/0010r0 Submission January 2013 Gerald ChouinardSlide 11 References IEEE 802.22.1, IEEE Standard for Information Technology—Telecommunications and information exchange between systems--Local and metropolitan area networks—Specific requirements, Part 22.1: Standard to Enhance Harmful Interference Protection for Low-Power Licensed Devices Operation in TV Broadcast Bands, 01 Nov. 2010