Performance Analysis of Hybrid Backoff Algorithm of Wireless LAN

To improve the saturation throughput and decrease the packet drop probability of wireless LAN, this paper proposes a new backoff algorithm, named as hybrid backoff algorithm, which can be used with IEEE 802.11 DCF. In the hybrid backoff algorithm, stations increase their contention window linearly after experiencing several collisions. Based on the Markov chain model, a new method to calculate the packet delay for successfully transmitted packets considering retry limit is also derived, which can be applied to standard DCF as well. The numerical results are presented and the effects of various parameters in hybrid backoff algorithm are studied. The results show that the hybrid backoff algorithm can achieve better performance than binary exponential backoff scheme employed in DCF.