Performance evaluation of IEEE 802.11 DCF in comparison with IEEE 802.11e EDCA

IEEE 802.11 Wireless Local Area Network (WLAN) is one of the most widely deployed wireless network technologies in the world today. However, 802.11 MAC algorithm is unable to support modern multimedia applications which require certain level of quality of service (QoS) guarantees in terms of consistent, timely and reliable data transfer. The 802.11e MAC protocol provides extension for adjustment of MAC parameters that were previously fixed in the standard 802.11 CSMA/CA contention mechanism. In this paper we conduct the evaluation study of 802.11e Enhanced Distributed Channel Access (EDCA) mechanism which supports service differentiation by assigning data traffic with different priorities based on their QoS requirements. The evaluation also includes the study of the role of different parameters IEEE 802.11e EDCA utilizes to realize service differentiation as well as the performance comparison of 802.11 and 802.11e along with its capability to resolve downlink/uplink fairness problem.