doc.: IEEE /0629r1 Submission July 2005 Bin Wang, ZTE CorporationSlide 1 ESS Load Balancing Requirements Notice: This document has been prepared to assist IEEE 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 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 Working Group. If you have questions, contact the IEEE Patent Committee Administrator at. Date: Authors:

doc.: IEEE /0629r1 Submission July 2005 Bin Wang, ZTE CorporationSlide 2 Abstract This document suggests ESS load balancing requirements for Wireless Network Managements.

doc.: IEEE /0629r1 Submission July 2005 Bin Wang, ZTE CorporationSlide 3 Agenda Introduction Load balancing illustration Current Load balancing in ESS Proposed text

doc.: IEEE /0629r1 Submission July 2005 Bin Wang, ZTE CorporationSlide 4 Introduction The meaning of load balancing: –The traffic in ESS maintain even distribution during it’s life, varies smoothly. –It is reasonable to satisfy high QoS requirement Applications that some STAs with low-level QoS requirements will be handed over to another AP, release their resources for the high QoS application. The necessity of load balancing: –The utilization of the ESS’s resources will be more evenly and effectively, could decrease drastic wave and boosting of traffic. –The characteristics of ESS: BSSs live in harmony with each other to form a ESS, and work together to supply services for STAs in the ESS. –To guarantee the continuity of the Application which has QoS requirements. –To prevent the happening of AP’s congestion and choke.

doc.: IEEE /0629r1 Submission July 2005 Bin Wang, ZTE CorporationSlide 5 Unbalanced Wireless Network

doc.: IEEE /0629r1 Submission July 2005 Bin Wang, ZTE CorporationSlide 6 AP Load Balancing

doc.: IEEE /0629r1 Submission July 2005 Bin Wang, ZTE CorporationSlide Current The APs in ESS manage their own load status respectively and independently, and the distribution of load burden among APs just according to RSSI. STA based hand over: After STA decide to handover, it break it’s current connection and then subscribe JOIN request to it’s favorite target; As current hand over is a new process of authentication and JOIN, it is in all probability to happen that STA frequently checking out from a AP and checking in back to the same one, which degrades the performance of ESS tremendously. Handover caused by load balancing is a “two-edged sword”. It could release the burden of AP or break the application of STA. So the action must be controlled and restricted. Advantages: –STA knows exactly the occasion of hand over. –STA knows exactly the strength of signals in around. Disadvantages: –No communication and correspond among BSSs. –The information STA can acquire is insufficient to make correct decision. –Huge differences between STAs from different venders. –Uncontrolled handover. –Heavy bss will retain their chaos, while the lighter couldn’t be a partaker.

doc.: IEEE /0629r1 Submission July 2005 Bin Wang, ZTE CorporationSlide 8 Load balancing in ESS When unbalancing happening, two methods can the network be operate: –Load limitation: when new STA JOIN, check load status and reject. –Let some STAs who has adequate condition to handover to light APs. An AP has more confederates to accomplish one task. Solve the same problem with more sufficient resources.

doc.: IEEE /0629r1 Submission July 2005 Bin Wang, ZTE CorporationSlide 9 AP based or AP-STA collaborated load balancing ESS has the inherent privilege to gather global load balancing information. Could make use of both the network condition and the client status. Could make the decision more accurate. Could make the command or recommend generated by load balancing policy more meaningful. Diminish the “bad” handover or “regret” handover.

doc.: IEEE /0629r1 Submission July 2005 Bin Wang, ZTE CorporationSlide 10 Proposed text TGv should support ESS Load balancing to improve network performance and enlarge the network tolerance. AP based or AP-STA collaborated load balancing policy will be reasonable.

doc.: IEEE /0629r1 Submission July 2005 Bin Wang, ZTE CorporationSlide 11 Feedback?