MPhil Thesis Defence


"Improving Fairness in the 802.11 Infrastructure Wireless Local Area
Networks"

By

Mr. Xiaoyang Lin


Abstract

Infrastructure wireless local area networks (WLANs) based on the IEEE
802.11 standard are growing tremendously and becoming widely deployed in
"hot spots" such as airports, hotels, cafes, libraries and other areas
which provide nomadic users with public access to the Internet. This
thesis considers the fairness (downlink/uplink fairness and fairness among
flows in the same direction) problems that exist in the infrastructure
WLANs and proposes software upgrade-based approaches to improve them.
First we show that ARED using ECN-marking (ARED-ECN) can effectively
control downlink congestion and prevent TCP uplink flows from starving TCP
downlink flows. Then we propose an approach, named wireless assured
forwarding (WAF) to further improve TCP downlink/uplink fairness. We
finally propose a virtual queue management approach, named VQ-RED to
improve both the downlink/uplink fairness and fairness among flows in the
same direction, regardless of the transport protocol used. The approaches
we propose (WAF and VQ-RED) are only deployed at the access point (changes
to the mobile nodes are unnecessary) and modifications to the MAC layer is
not required.


Date:				Friday, 24 June 2005

Time:				10:30a.m-12:30p.m.

Venue:				Room 2504
				Lifts 25-26

Committee Members:		Dr. Jogesh Muppala (Supervisor)
                        	Dr. Gary Chan (Chairperson)
                        	Dr. Brahim Bensaou


**** ALL are Welcome ****