A survey about IEEE 802.11e for better QoS in WLANs

Abstract

The demand for Quality of Service (QoS) is increasing day by day in many multimedia applications with the rapid implementations of Wireless Local Area Networks (WLANs). The task group 802.11e of the Institute of Electrical and Electronic Engineers (IEEE 802.11e) is working to improve the QoS in WLAN by introducing two new functions namely Enhanced Distributed Coordination Function (EDCF) and Hybrid Coordination Function (HCF) since these two offer some enhancements beyond the original two functions Distributed Coordination Function (DCF) and Point Coordination Function (PCF) of IEEE 802.11 WLAN. To provide better QoS, Differentiated Service (DiffServ) is coupled with the IEEE 802.11e. This paper briefly describes QoS issues and concepts in general, the DCF and PCF of 802.11, the EDCF and HCF of IEEE 802.11e, and the coupling between the IEEE 802.11e and DiffServ. © 2010 Springer Science+Business Media B.V.