A controlled-access scheduling mechanism for QoS provisioning in IEEE 802.11e wireless LANs

Wireless Local Area Networks (WLAN) are being deployed at a rapid pace and in different environments. As a result, the demand for supporting a diverse range of applications over wireless access networks is becoming increasingly important. In particular, multimedia applications, such as Video and Voice, have specific delay and bandwidth requirements that cannot be fulfilled by the current IEEE 802.11-based WLANs. To overcome this issue, new enhancements are being introduced to the Medium Access Control (MAC) layer of the 802.11 standard under the framework of the IEEE 802.11e standard which is still a work in progress. The 802.11e standard offers new features for supporting Quality of Service (QoS) in the MAC layer, it however does not mandate a final solution for QoS issues and intentionally leaves it to the implementers to devise their own methods using the available features. We present a solution that employs the controlled access features of the 802.11e to provide per-session guaranteed quality-of-service. Our design comprises of a scheduler that assign guaranteed service times to individual sessions using a fair scheduling algorithm. We show that the proposed solution outperforms other methods that are contention and priority based.