The Performance Evaluation of IEEE 802.11e for QoS Support in Wireless LANs

摘要

During the past few years the widespread use of the wireless local area networks (WLANs) communication technique is one of the most popular technologies in data telecommunications and networking. With the increasing variety of multimedia applications, it is needed to develop a mechanism for the quality of service (QoS) to support different types of traffic. The IEEE 802.11 protocol has achieved worldwide acceptance with WLANs with minimum management and maintenance costs. However, IEEE 802.11 can only provide a best effort service and does not support the QoS. In this paper, we pay attention to the enhanced distributed coordination function (EDCF) of WLANs. First, we modify the Ziouva and Antonakopoulous's (ZA's) model and then extend the model to support EDCF. We study the behavior of the station within a Markov chain model, and present a more accurate analysis of the EDCF and also study the saturation throughput when the maximum load that the system can support is reached. The numerical results show that the modified model has a better performance than the ZA's model under an ideal channel scenario.