Improving QoS in 802.11e WLAN
			-----------------------------

			       Ratan K. Guha
			School of Computer Science
			University of Central Florida
			      Orlando, Florida


			         Abstract

				 
802.11e is currently under discussions to introduce Quality of Service
(QoS) requirements in Wireless LAN (WLAN), so that it can overcome the
shortcomings of the legacy 802.11. 802.11e provides QoS based on traffic
categories. In this talk, we consider how to provide better QoS for
802.11e MAC protocol in WLAN. We suggest some enhancement to current MAC
802.11e protocol that will be able to provide QoS depending on class to
whom a node belongs to in addition to the traffic category used by the
node. Various tradeoffs can be provided in our suggested solution
depending on the importance of objective function: bandwidth utilization
or prioritization of node's ability to transmit. In addition, we propose
a polling scheme in which QoS nodes communicate with the access point
telling it about their queue status and letting the access point then
decide when it needs to poll such a node in the next polling round. We
also present simulation results supporting our case.