Frequent Handover Authors: Date:2006-01-04 Jan 2006 Month Year 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 <http:// ieee802.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 Chair <stuart.kerry@philips.com> 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 <patcom@ieee.org>. Bin Wang, ZTE Corporation Bin Wang, ZTE Corporation

Month Year Jan 2006 Jan 2006 Abstract This document suggests the solution for frequent handover of STA in ESS for Wireless Network Management. Bin Wang, ZTE Corporation Bin Wang, ZTE Corporation

Agenda Possible FH Avoid Condition Frequent handover avoid illustrator Month Year Jan 2006 Jan 2006 Agenda Possible FH Avoid Condition Frequent handover avoid illustrator Frequent Handover process Frequent handover frame format Possible approach for frequent handover detection Proposed text Bin Wang, ZTE Corporation Bin Wang, ZTE Corporation

Introduction What should we solve about this problem: Month Year Jan 2006 Jan 2006 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. Bin Wang, ZTE Corporation Bin Wang, ZTE Corporation

Possible FH Avoid Condition Jan 2006 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 Bin Wang, ZTE Corporation

Frequent handover avoid illustrator Jan 2006 Frequent handover avoid illustrator Bin Wang, ZTE Corporation

Frequent Handover Process Jan 2006 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. Bin Wang, ZTE Corporation

Frequent Handover process (optional) Jan 2006 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. Bin Wang, ZTE Corporation

Frequent handover frame format Jan 2006 Frequent handover frame format HO request frame format Bin Wang, ZTE Corporation

Frequent handover frame format Jan 2006 Frequent handover frame format HO response frame format Bin Wang, ZTE Corporation

Frequent handover frame format Jan 2006 Frequent handover frame format FHAU frame format Bin Wang, ZTE Corporation

Frequent handover measurement report Month Year Jan 2006 Jan 2006 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; Bin Wang, ZTE Corporation Bin Wang, ZTE Corporation

Frequent handover avoid policy Jan 2006 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; Bin Wang, ZTE Corporation

Possible approach for frequent handover detection Month Year Jan 2006 Jan 2006 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 Bin Wang, ZTE Corporation Bin Wang, ZTE Corporation

Jan 2006 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 Bin Wang, ZTE Corporation

Poll for TGv Objectives Jan 2006 Poll for TGv Objectives Should TGv take frequent handover as a new requirement ? Yes: No: Abstain: Bin Wang, ZTE Corporation

Jan 2006 Feedback? Bin Wang, ZTE Corporation