The performance of MAC layer protocol in wireless network is the main factor that determines the efficiency in sharing and utilizing the limited bandwidth resources. In this paper, a practicable distributed backoff algorithm, which is named Adaptive Contention Window Backoff (ACWB) for IEEE 802.11wireless LAN is presented.

ACWB algorithm tunes the Contention Window size in a distributed manner at run-time in order to maximize the throughput and fairness according to the idle backoff interval statistics. Simulation results indicate that the proposed scheme provides a remarkable improvement in terms of the network throughput while maintaining good fairness.