Dynamic backoff time adjustment with considering channel condition for IEEE 802.11e EDCA

Abstract

Many enhanced schemes of IEEE 802.11e have been proposed to meet the increasing demand for Quality of Service (QoS). Most of them adjust the parameters, such as Contention Window (CW), according to whether the transmission is successful or failed, but don't consider the channel condition (bandwidth) at transmitting frames. In a wireless network, the channel condition is time-varying due to some factors such as station mobility, time-varying interference, and location-dependent errors. In this paper, we propose the Enhanced Distributed Channel Access with Link Adaptation (EDCA-LA) algorithm by adapting with the time-varying channel condition. Our idea is to set the smaller backoff time for a station which has a better channel to achieve higher overall performance. Simulation results show that EDCA-LA outperforms the standard EDCA on throughput and average end-to-end delay. © 2008 Springer Berlin Heidelberg.