A novel contention window backoff algorithm for IEEE 802.11 wireless networks

Abstract

The performance of IEEE 802.11 distributed coordination function (DCF) protocol vitally depends on the number of contender stations and the contention window size (CW). The contribution of this paper is twofold. First, we analyze the performance of IEEE 802.11 DCF in term of CW optimization and the effect of CW on the throughput and collision probability for binary exponential backoff algorithm (BEB) used in the DCF. Secondly, we estimate the number of contender stations and find an optimal contention window CW _opt for the BEB based on the number contender stations, and compared the performance of the propose algorithm CW _opt with the BEB. The Propose algorithm dynamically adjusts the CW according to the network states. The simulation results show that the propose algorithm outperform the BEB in term of throughput improvement and collision probability.