Dynamic polling management for QoS differentiation in IEEE 802.11e wireless LANs

Upcoming IEEE 802.11e standard aims to support quality of service (QoS) for multi-priority services, which is not yet available in current wireless local area network (WLAN) systems. We propose to combine the enhanced distributed coordination function (EDCF) and point coordination function (PCF) of IEEE 802.11e protocols. The scheme dynamically adds and deletes voice station IDs in polling list, utilizing the talkspurt-silence alternation characteristic of speech traffic. Meanwhile, the real-time and non real-time traffic are also differentiated by means of different EDCF parameters during contention period. Extensive simulation results demonstrate that the dynamic polling management in combination with EDCF is able to achieve satisfying QoS differentiation, while at the same time significantly improve the system performance in terms of throughput and data drop rate.