Adjustment mechanism for the IEEE 802.11 contention window: An efficient bandwidth sharing scheme

In this paper, we propose a new solution to cope with the unfairness limitations of the Distributed Coordination Function (DCF) algorithm. Indeed, in current widely deployed IEEE 802.11b Wireless Local Area Networks (WLAN), the performance of all the competing access nodes are dramatically affected once the bit rate of one station degrades. This anomaly is due to the unfairness behavior of the DCF algorithm. To avoid this, our solution is based on multiple backoff windows principle. We demonstrate through both analytical models and simulations the efficiency of our proposal. Our results show that the proposed algorithm enables fair bandwidth sharing and increases significantly the total network throughput.