AP Load Balancing Requirements Month Year May 2005 May 2005 AP Load Balancing Requirements Authors: Date:2005-05-08 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>. Emily Qi, Intel Corporation Emily Qi, Intel Corporation

Month Year May 2005 May 2005 Abstract This document suggests BSS load balancing requirements for Wireless Network Management. Emily Qi, Intel Corporation Emily Qi, Intel Corporation

Agenda Rationale for BSS Load Balancing Month Year May 2005 May 2005 Agenda Rationale for BSS Load Balancing AP-STA Cooperative Load Balancing Suggested Load Balancing Messages Emily Qi, Intel Corporation Emily Qi, Intel Corporation

Unbalanced Wireless Network May 2005 Unbalanced Wireless Network Throughput No. of users AP and Clients need to collaborate for optimal network use Emily Qi, Intel Corporation

AP and Clients balance load to optimize network use May 2005 BSS Load Balancing Throughput No. of users AP and Clients balance load to optimize network use Emily Qi, Intel Corporation

Rationale for BSS Load Balancing May 2005 Rationale for BSS Load Balancing Increase WLAN aggregate throughput by increasing individual STA throughput Improve user experience by more optimally distributing the load over serving APs Balancing load to improve QoS effectiveness for VoIP and Video stream Suggested Requirement: TGv shall support BSS load balancing to improve wireless network throughput and QoS effectiveness. Emily Qi, Intel Corporation

Possible Approaches Network Controlled Load Balancing May 2005 Possible Approaches Network Controlled Load Balancing AP directs STA to a lightly loaded AP and initiates connection Pros: Network has a broad vision of BSS load and STA can be better redistributed between serving APs Cons: STA may not be able to achieve optimum throughput because Network may not know STA’s local receiving signal strength and SNIR STA controlled load Balancing STA selects the best AP to optimize its own throughput/QoS, based on QBSS load information and local SNIR/RSSI Pros: STA has the best idea about when to roam and which AP to serve its needs Cons: May result in a “Gold rush” in a heavily loaded environment Emily Qi, Intel Corporation

AP-STA Cooperative Load Balancing May 2005 AP-STA Cooperative Load Balancing AP sends STA Load Balancing management message, which includes: A list of one or more nearby lightly loaded APs (candidate APs) that it offers, which may include fields from Neighbor Report Element (TGk) and Fast BSS Transition IEs (TGr) Timeliness indication for expiration time Strong/Mild indication for gravity (e.g. Strong = STA really should consider this or face potential service degradation or disruption; Mild = service would probably be better if STA moved; etc) Once STA receives this message, STA can decide which AP to roam to and when to roam Suggested Requirement: TGv shall support AP and STA Cooperative Load Balancing Emily Qi, Intel Corporation

Suggested Load Balancing Messages May 2005 Suggested Load Balancing Messages Direct Roaming WNM Management frame Admission Control Response Message if the status is rejected 802.11e Action Frame (Re-)association Response Message if the status is rejected 802.11 Management Frame Emily Qi, Intel Corporation

May 2005 Feedback? Emily Qi, Intel Corporation