Contention Window Based Fairness Backoff algorithm in Ad hoc networks

The backoff mechanism in 802.11 is binary exponential back-off (BEB) algorithm. When this mechanism is applied in ad hoc networks, the winner node after contention will gain the resource easier later while the fail node will harder to obtain the resource. In this paper, the unfairness of MAC and the throughput model of node in ad hoc networks are analyzed in depth, and then a fairness backoff algorithm named CWBFB (contention window based fairness backoff) is proposed. In CWBFB, the concept of authority and ordinary nodes is introduced into ad hoc networks for the first time, and meanwhile the backoff mechanism is also improved. The simulated results show that CWBFB enhances the fairness of channel-access effectively in ad hoc networks.