1. doc.: IEEE 802.11-07/1944r0 Submission January 2007 Na Shan, Huawei Technologies Co., LtdSlide 1 BB selection using Connectivity Reports Notice: This document has been prepared to assist IEEE 802.11. 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 802.11. 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 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:// ieee802.org/guides/bylaws/sb-bylaws.pdfstuart.kerry@philips.compatcom@ieee.org Date: 2007-01-08 Authors:

2. doc.: IEEE 802.11-07/1944r0 Submission January 2007 Na Shan, Huawei Technologies Co., LtdSlide 2 Abstract This submission proposes a BB selection method that allows a designated BB to properly select the next BB. It is intended to resolve problems with the current BB selection method.

3. doc.: IEEE 802.11-07/1944r0 Submission January 2007 Na Shan, Huawei Technologies Co., LtdSlide 3 BB Selection Rationale The BB has to make sure that the neighbor appearing at the head of the list is supporting frame transmission to MPs in power save mode and Designated Beacon broadcasting. The selection of the next Beacon Broadcaster may be based on Connectivity Reports allowing the current BB to select the next BB in such a manner that network connectivity is ensured. The beacon broadcaster may obtain the connectivity status of the network and apply this information to select the next BB in the network.

4. doc.: IEEE 802.11-07/1944r0 Submission January 2007 Na Shan, Huawei Technologies Co., LtdSlide 4 Current Connectivity Report Element Octets : 1 1266…66…6K IDLengthConnectivity Report Control SSIDMAC Address of Beaconing MP 1 …MAC Address of Beaconing MP n MAC Address of Connectivity Reporting MP 1 …MAC Address of Connectivity Reporting MP n Beacon and Connectivity Reporting Power management mode Connectivity Report element Connectivity Report control field Bits:0-34-678-15 ReservedAmount of Heard Beacons Power Management mode of Reporting MP Amount of Reported MPs

5. doc.: IEEE 802.11-07/1944r0 Submission January 2007 Na Shan, Huawei Technologies Co., LtdSlide 5 Problems with the current BB selection method Figure 1 Example topology: MP1 MP3MP4 MP2 MP6MP5 MP1 can hear MP2, MP3, MP4. MP2 can hear MP1, MP3, MP6 MP3 can hear MP1, MP2, MP6. MP4 can hear MP1, MP5 MP5 can hear MP4. MP6 can hear MP2, MP3

6. doc.: IEEE 802.11-07/1944r0 Submission January 2007 Na Shan, Huawei Technologies Co., LtdSlide 6 Problems with the current BB selection method (cont.) Case 1: MP1 MP3MP4 MP2 BB MP6 BB non-BB MP5 During the Connectivity Reporting Interval, MP1,MP6 and MP5 transmit beacons. MP2,MP3 and MP4 transmit Connectivity Reports. Figure 2

7. doc.: IEEE 802.11-07/1944r0 Submission January 2007 Na Shan, Huawei Technologies Co., LtdSlide 7 Problems with the current BB selection method (cont.) Case 2: MP1 MP3MP4 MP2 BB MP6 non-BB BB MP5 During the Connectivity Reporting Interval, MP1,MP6 and MP5 transmit beacons. MP2,MP3 and MP4 transmit Connectivity Reports. Figure 3

8. doc.: IEEE 802.11-07/1944r0 Submission January 2007 Na Shan, Huawei Technologies Co., LtdSlide 8 Problems with the current BB selection method (cont.) Amount of Heard Beacons Amount of Reported MPs Beaconing MP Connectivity reporting MP 23MP1MP6MP3 Amount of Heard Beacons Amount of Reported MPs Beaconing MP Connectivity reporting MP 23MP1MP6MP2 Amount of Heard Beacons Amount of Reported MPs Beaconing MP 22MP1MP5 MP2 MP3 MP4

9. doc.: IEEE 802.11-07/1944r0 Submission January 2007 Na Shan, Huawei Technologies Co., LtdSlide 9 Problems with the current BB selection method (cont.) The problem: When the designated BB-MP1 decides to switch the role –Case 1: MP4 is the best choice. –Case 2: MP2 or MP3 is the best choice. The Connectivity Reports in both case 1 and case 2 are same for each non-beaconing MP, and so the three non- beaconing MPs have the same chance to become the next BB. This is inappropriate. Therefore, the current Connectivity Report element can not provide enough information for MP1 to make the best choice.

10. doc.: IEEE 802.11-07/1944r0 Submission January 2007 Na Shan, Huawei Technologies Co., LtdSlide 10 Modified Connectivity Report element Octets: 1 1266…66…6 IDLengthConnectivity Report Control SSIDMAC Address of BB 1 …MAC Address of BB n MAC Address of Beaconing non-BB 1 …MAC Address of Beaconing non-BB n 6…6K MAC Address Of Connectivity Reporting MP 1 …MAC Address of Connectivity Reporting MP n Beacon and Connectivity Reporting Power management mode Modified Connectivity Report element

11. doc.: IEEE 802.11-07/1944r0 Submission January 2007 Na Shan, Huawei Technologies Co., LtdSlide 11 Modified Connectivity Report element (cont.) Bits:01-34-678-15 ReservedAmount of Heard BB Beacons Amount of Heard non-BB Beacons Power Management mode of Reporting MP Amount of Reported MPs Modified Connectivity Report Control field

12. doc.: IEEE 802.11-07/1944r0 Submission January 2007 Na Shan, Huawei Technologies Co., LtdSlide 12 Summary Proposes a BB selection method that allows a designated BB to properly select the next BB. Solves the problem that exists in the current BB selection method. Adds MAC Address of BBs field and MAC Address of Beaconing non-BBs field to Connectivity Report element. Adds Amount of Heard BB beacons subfield and Amount of Heard non-BB beacons subfield to Connectivity Report Control field.

13. doc.: IEEE 802.11-07/1944r0 Submission January 2007 Na Shan, Huawei Technologies Co., LtdSlide 13 Thank you for your attention!