Modeling and evaluation of an adaptive contention window Backoff algorithm for Ad Hoc networks

According to the IEEE 802.11 for ad hoc networks, the distributed coordination function (DCF) of ad hoc networks was modified, and an adaptive minimum contention window binary exponential backoff algorithm (AWBEB algorithm) was present. The bidimensional discrete-time Markov Chain model for AWBEB algorithm was established, the stationary distribution probabilities and the transmission probability of AWBEB algorithm were educed. The throughput, the stationary throughput and the system delay of AWBEB algorithm were analyzed theoretically, and then the performance of AWBEB algorithm were simulated and evaluated. The study results show that the system throughputs and the system delay of AWBEB algorithm are better than those of DCF algorithm. The study results also show that the results of AWBEB algorithm performance such as system throughputs and the system delay simulated by program agree with the evaluation results preferably.