1. doc.: IEEE 802.11-06/1280r1 Submission Jan 2006 Bin Wang, ZTE CorporationSlide 1 Frequent Handover 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:2006-01-04 Authors:

2. doc.: IEEE 802.11-06/1280r1 Submission Jan 2006 Bin Wang, ZTE CorporationSlide 2 Abstract This document suggests the solution for frequent handover of STA in ESS for Wireless Network Management.

3. doc.: IEEE 802.11-06/1280r1 Submission Jan 2006 Bin Wang, ZTE CorporationSlide 3 Agenda Possible FH Avoid Condition Frequent handover avoid illustrator Frequent Handover process Frequent handover frame format Possible approach for frequent handover detection Proposed text

4. doc.: IEEE 802.11-06/1280r1 Submission Jan 2006 Bin Wang, ZTE CorporationSlide 4 Introduction What should we solve about this problem: –When and how to diminish the “ping pang effect”; –No or less infection on the normal roaming behaviour of STA; It is necessary to collect all the factors about handover and evaluate these factors when handover happens. HoOP will be helpful for both the network side and the client side.

5. doc.: IEEE 802.11-06/1280r1 Submission Jan 2006 Bin Wang, ZTE CorporationSlide 5 Possible FH Avoid Condition Time varying wireless channel environment –radio circumstance –client's movement Requirement of load balancing –user number or traffic –traffic’s level, QoS Transmit power adjustment or advanced power control Support dynamic channel select And so on

6. doc.: IEEE 802.11-06/1280r1 Submission Jan 2006 Bin Wang, ZTE CorporationSlide 6 Frequent handover avoid illustrator

7. doc.: IEEE 802.11-06/1280r1 Submission Jan 2006 Bin Wang, ZTE CorporationSlide 7 Frequent Handover Process In a distributed infrastructure network, FHAAP should monitor and supervise every STA’s handover behavior. When the STA init a handover request (whether fast transition or not), some measurement report will be transmit to the FHAAP. The AP could init a 802.11k measurement report process or the measurement report be transmitted within the HO request frame. FHAAP memorize the measurement report and perform the frequent handover detection. If FHAAP can confirm the STA has been in frequent handover status, FHAAP will enable or update the FHAP (frequent handover avoid policy) of the STA and the other FHAAP in the same ESS, so as to avoid the STA’s frequent handover.

8. doc.: IEEE 802.11-06/1280r1 Submission Jan 2006 Bin Wang, ZTE CorporationSlide 8 Frequent Handover process (optional) In the FH status, the STA who want to handover will request a FH request to the FHAAP it connected, and the FHAAP will control the request according to the FHAP.

9. doc.: IEEE 802.11-06/1280r1 Submission Jan 2006 Bin Wang, ZTE CorporationSlide 9 Frequent handover frame format HO request frame format

10. doc.: IEEE 802.11-06/1280r1 Submission Jan 2006 Bin Wang, ZTE CorporationSlide 10 Frequent handover frame format HO response frame format

11. doc.: IEEE 802.11-06/1280r1 Submission Jan 2006 Bin Wang, ZTE CorporationSlide 11 Frequent handover frame format FHAU frame format

12. doc.: IEEE 802.11-06/1280r1 Submission Jan 2006 Bin Wang, ZTE CorporationSlide 12 Frequent handover measurement report The measurement report that a STA pass to the ESS should contain: –1)average RSSI list of candidate APs; –2)neighbor report (11k); –3)handover threshold status; –4)transmit power; –5)channel quality; –6)the load level of candidate APs;

13. doc.: IEEE 802.11-06/1280r1 Submission Jan 2006 Bin Wang, ZTE CorporationSlide 13 Frequent handover avoid policy The FHAP will contain following parameter: –1)adaptive handover threshold value; –2)frequent handover status; –3)transmit power control; –4)dynamic channel control; –5)load scheme control;

14. doc.: IEEE 802.11-06/1280r1 Submission Jan 2006 Bin Wang, ZTE CorporationSlide 14 Possible approach for frequent handover detection Distinguish different kind of handover ; Gather STA’s information during handover; –Evaluate the history of signal strength; –Evaluate the transmit power; –Evaluate the load information; –Evaluate the channel quality; –Evaluate the location information; –Evaluate the handover window status; Judgments will depend on: –The target of handover –The handover times during a period of time

15. doc.: IEEE 802.11-06/1280r1 Submission Jan 2006 Bin Wang, ZTE CorporationSlide 15 Proposed text TGv should consider to solve the problem of frequent handover in wireless network management, supply detect/avoid/control mechanism. TGv should take the following factors into account when solve frequent handover: –Signal strength –Single direction channel caused by AP’s different emission power from different vendors or different model. –Network resources or load information To include Frequent Handover Control as requirement item to TGv work list To include Frequent Handover Control as additional item in the TGv Objectives document

16. doc.: IEEE 802.11-06/1280r1 Submission Jan 2006 Bin Wang, ZTE CorporationSlide 16 Poll for TGv Objectives Should TGv take frequent handover as a new requirement ? Yes: No: Abstain:

17. doc.: IEEE 802.11-06/1280r1 Submission Jan 2006 Bin Wang, ZTE CorporationSlide 17 Feedback?