Performance analysis of modified backoff algorithm in IEEE 802.11 networks

The primary medium access control (MAC) protocol for wireless local area network (WLAN) is distributed coordination function (DCF) for IEEE 802.11. The binary exponential backoff (BEB) scheme used in 802.11 DCF mechanism may suffer from low throughput when the number of stations gets large due to the lack of flexibility in choosing the contention window size imposed by the standard. To improve the system throughput of IEEE 802.11 DCF, in this paper we propose a modification to the conventional BEB. The simulation results show that the modified backoff algorithm helps improve the saturation throughput of the DCF protocol using the same standard parameter settings. In addition, it is shown that the throughput performance of the system depends on the total number of stations and the maximum backoff stage.