Saturated throughput analysis of IEEE 802.11e using two-dimensional Markov chain model

IEEE 802.11e standard has been recently published to introduce quality of service (QoS) support to the conventional IEEE 802.11 wireless local area network (WLAN). Enhanced Distribution Channel Access (EDCA) is used as the fundamental access mechanism for the medium access control (MAC) layer in IEEE 802.11e. In this paper, a novel Markov chain model with a simple architecture for EDCA performance analysis under the saturated traffic load is proposed. Compared with existing analytical models, the proposed model considers more features of EDCA. Firstly, the effect of using different arbitration interframe spaces (AIFSs) is analyzed. Secondly, the possibility that a station's backoff procedure may be suspended due to transmission from other stations is considered. We consider that the contention zone specific transmission probability caused by using different AIFSs can affect the occurrence of the backoff suspension state. Based on the proposed model, saturated throughput of EDCA is obtained. Simulation study is performed, which demonstrates that the proposed model has better accuracy than other models.