Dynamic contention window adjustment scheme for improving throughput and fairness in IEEE 802.11 wireless LANs

In this paper, we propose a new medium access control (MAC) scheme called dynamic contention window adjustment (DCWA) in saturated load conditions, which dynamically optimizes each active node´s backoff process in wireless LANs. The key idea is to enable each node to adjust its Contention Window (CW) to approach the optimal one that will make the throughput achieve or approach the maximum. Meanwhile, all the nodes will maintain approximately identical CWs to guarantee fair channel sharing among all nodes. Through simulation comparison with the original 802.11 DCF and previous enhancement approaches, our proposed scheme can greatly improve the throughput, while maintaining good fairness.