A Comprehensive Study of the IEEE 802.11e Enhanced Distributed Control Access (EDCA) Function
Chunyu Huy, Jennifer C. Houz · 2006
This technical report presents a comprehensive study of the Enhanced Distributed Control Access (EDCA) function dened in IEEE 802.11e. All the three factors are considered. They are: contention window size (CW), arbitration inter-frame space (AIFS), and transmission opportunity limit (TXOP). We rst propose a discrete Markov chain model to describe the channel activities governed by EDCA. Then we evaluate the individual as well as joint effects of each factor on the throughput and QoS performance. We obtain several insightful observations showing that judiciously using the EDCA service differentiation mechanism is important to achieve maximum bandwidth utilization and userspecied QoS performance. Guided by our theoretical study, we devise a general QoS framework that provides QoS in an optimal way. The means of realizing the framework in a specic network is yet to be studied.