1. doc.: IEEE 802.22-07/0129r2 Submission March 2007 David Mazzarese, Samsung ElectronicsSlide 3 802.22.1 Beacon Frame Options IEEE P802.22 Wireless RANs Date: 2007-03-14 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 Carl R. StevensonCarl 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 802.22 Working Group. If you have questions, contact the IEEE Patent Committee Administrator at patcom@iee.org.patcom@iee.org >

2. doc.: IEEE 802.22-07/0129r2 Submission March 2007 David Mazzarese, Samsung ElectronicsSlide 4 Abstract The possible beacon frame sizes are presented according to different levels of security and error-correction coding, based on the current security proposal and rate ½ FEC proposal. The impact of respective lengths of the beacon frame and the WRAN superframe is analyzed in terms of the latency before the WRAN can schedule a long quiet period without interrupting the superframe preamble.

3. doc.: IEEE 802.22-07/0129r2 Submission March 2007 David Mazzarese, Samsung ElectronicsSlide 5 Signature CRC #3 Channel Map PSDU (except channel map) (in the clear) Certificate CRC #2 CRC #1 1 49 (32+1+16) 2 5 332 18 111 bytes (92.5 ms + 2.5 ms = 95 ms) 2 Signature PSDU (except channel map) (in the clear) CRC #2 CRC #1 2 49 2182 106 bytes (88.3 ms + 2.5 ms = 90.8 ms) Signature PSDU (except channel map) (in the clear) CRC #2 CRC #1 4 49 2182 71 bytes (59.2 ms + 2.5 ms = 61.7 ms) PSDU (except channel map) (in the clear) CRC #1 5 182 27 bytes (22.5 ms + 2.5 ms = 25 ms) CRC #3 2 Channel Map 5 CRC #2 2 PSDU (except channel map) (in the clear) CRC #1 6 182 20 bytes (16.6 ms + 2.5 ms = 19.1 ms) Signature Channel Map PSDU (except channel map) (in the clear) Certificate CRC #2 CRC #1 3 49 (32+1+16) 5 33 2 18 78 bytes (65 ms + 2.5 ms = 67.5 ms) 2 Pros and consFEC on PSDU (and CRC) FEC on PSDU + Sign (and CRC) FEC on PSDU + Sign + Certif (and CRC) Beacons can authenticate 131 bytes 109.1+3.3 = 112.4 ms 187 bytes 155.9+3.3 = 159.2 ms 222 bytes 189+3.3 = 192.3 ms No channel Map 126 bytes 105+3.3 = 108.3 ms 177 bytes 147.5+3.3 = 150.8 ms 212 bytes 176.7+3.3 = 180 ms Beacons can’t authenticate 98 bytes 81.7+3.3 = 85 ms 156 bytes 130+3.3 = 133.3 ms n/a Beacons can’t authenticate No channel Map 91 bytes 75.8+3.3 = 79.1 ms 142 bytes 118.3+3.3 = 121.6 ms n/a No security 47 bytes 39.2+3.3 = 42.5 ms n/a No security No channel Map 40 bytes 33.4+3.3 = 36.7 ms n/a Quiet period length With FEC on PSDU only, no authentication at keep-out distance, but the important information to protect incumbents can be recovered. 1 Slot (sync burst): without FEC: 2.5 ms with FEC: 3.3 ms Frame structures without FEC (March 2007)

4. doc.: IEEE 802.22-07/0129r2 Submission March 2007 David Mazzarese, Samsung ElectronicsSlide 6 Constraints on latency of quiet period scheduling according to the respective lengths of the 802.22.1 beacon and of the 802.22 superframe As long as the quiet period length is smaller than one superframe length (158 ms without SCH), the WRAN does not need to interrupt the superframe preamble to schedule a quiet period, but it needs to wait until the desired part of the beacon frame does not interrupt the superframe preamble. If D+P < S, the quiet period can be scheduled in the current superframe (it is assumed that B < S) Otherwise the minimum number of superframes to wait for before scheduling a quiet period is WRAN Superframe SCH Beacon Frame B D SH Quiet period P

5. doc.: IEEE 802.22-07/0129r2 Submission March 2007 David Mazzarese, Samsung ElectronicsSlide 7 Mean and Maximum Latency Beacon frame Quiet period 112.4 ms159.2 ms 36.7 msMean latency: 36 ms Max latency: 160 ms 85 msMean latency: 122 ms Max latency: 320 ms 133.3 msMean latency: 11 sec Max latency: infinite Some cases from slide 5

6. doc.: IEEE 802.22-07/0129r2 Submission March 2007 David Mazzarese, Samsung ElectronicsSlide 8 Signature CRC #3 Channel Map PSDU (except channel map)Certificate CRC #2 CRC #1 44 2 5 312 15 120 bytes + RTS/ANP period = 103.24 ms 2 Beacon blockRequired quiet period length Mean latency before being able to schedule Max latency before being able to schedule (it takes one more superframe to detect the beacon) PHR + MSF 129.97 ms29 ms160 ms (1 superframe) PHR + MSF 1 + MSF 272.43 ms87 ms320 ms (2 superframes) PHR + MSF 1 + MSF 2 + MSF 3 99.91 ms142 ms320 ms (2 superframes) RTS/ANP Slot: 4 bytes 3.3 ms Frame structure with FEC (11 April 2007) MSF 1 (34 bytes after FEC with puncturing) MSF 2 (no FEC, stronger CRC) MSF 3 (no FEC, stronger CRC) For comparison, if MSF 2 was also protected by FEC with rate 1/2, the quiet period for MSF1 and MSF2 would be 114.89 ms and the beacon would be 145.70 ms. This would lead to a max latency of 8 superframes (1280 ms), and a mean latency of 4 superframes (514 ms). PHR 2 1 byte PHY header + 1 bytes (e.g. padding)