Adaptive rate control Requirements July 2005 July 2005 July 2005 Adaptive rate control Requirements Date:2005-07-1 Authors: 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>. Feng Li, ZTE Corporation Feng Li, ZTE Corporation

July 2005 July 2005 July 2005 Abstract The objective of this document is to recommend the requirements of the adaptive rate control in WLAN to TGv. Feng Li, ZTE Corporation Feng Li, ZTE Corporation

Agenda Pros/Cons of current transfer rate control Recommendations July 2005 July 2005 July 2005 Agenda Pros/Cons of current transfer rate control Recommendations Rationale for adaptive rate control Text proposal Feng Li, ZTE Corporation Feng Li, ZTE Corporation

Pros/Cons of current transfer rate control (1/2) July 2005 Pros/Cons of current transfer rate control (1/2) Data transfer rate is fixed during each frame sequence exchange. Little channel quality information is transmitted between the transmitter and receiver before the transmission. Feng Li, ZTE Corporation

Pros/Cons of current transfer rate control (1/2) July 2005 Pros/Cons of current transfer rate control (1/2) Advantages: Simple control, low overhead, low cost Disadvantages: Not time-varying mobile channel adaptive - due to the relative fixed transfer rate Inaccurate evaluation of channel quality - due to poor knowledge in the forward channel quality. Unsuitable for the case of different forward/backward channel quality latency in statistical evaluation of channel quality - Impossible to response quickly to the fast and abrupt changing channel. poor performance of whole network - Mismatch of data transfer rate with the quality of channel, which may lead to high frame error rate, long latency, low throughput Feng Li, ZTE Corporation

Recommendations Practice scenario: July 2005 Recommendations Practice scenario: Spectrum usage Wireless mobile environment Sophisticated environments RF management MIMO VoWLAN Hot spot Suggest the consideration of adaptive rate control in the requirement of TGv Feng Li, ZTE Corporation

Rationale for adaptive rate control July 2005 Rationale for adaptive rate control Definition of adaptive rate control: Traffic transfer rate is able to be adjusted adaptively to be more appropriate according to real channel quality. What can we get from adaptive rate control: Robustness of traffic transaction. QoS of traffic transaction can be guaranteed once the STA obtain a transmission opportunity (TXOP). Improvement of the FER performance in case of poor channel quality by adaptively reducing the data transfer rate. Enhancement of the spectrum usage by adaptively optimizing the transfer rate. Improvement of the network efficiency, with higher throughput and lower latency, and increase of the mobility of STA. Feng Li, ZTE Corporation

July 2005 Text proposal to TGv During the process of frame sequence exchange, the STA should be able to adjust the transfer rate correspondingly based on the channel quality information received. Advantages: - Adaptive rate control has more superior than fixed rate control in case of wireless mobile channels - Adaptive rate control based on segments during frame sequence exchange offers reliable data transmission - Adaptive rate control enhances network efficiency - Accurate channel quality measurement is able to be obtained based on forward channel quality evaluation - Adaptive rate control is more suitable in the case of different forward/backward channel quality. Disadvantages: - Additional scheduling complexity and network overhead Feng Li, ZTE Corporation

July 2005 Feedback! Feng Li, ZTE Corporation