A back-off scheme for IEEE802.11 wireless LANs

Conventional IEEE802.11 wireless LANs employ the binary exponential back-off scheme to determine a back-off window size. Performance evaluations of the binary exponential back-off scheme and several enhanced ones have been done under an assumption that each station can store away only one packet with its transmission buffer. Under such assumption, enhanced schemes provide better performance, however they do not work well under a realistic condition that each station has more larger transmission buffer. In this paper, we propose a back-off scheme in which each station changes the back-off window size according to the load conditions. In order to evaluate performance of the proposed scheme, we build a queueing model and execute computer simulation. Simulation results show that the proposed scheme provides a higher throughput than the conventional ones. Moreover, under the proposed scheme, the number of stations has a slight influence on the performance.