End-to-end delay analysis and admission control in 802.11 DCF WLANs

In this paper, we first present an analytical model to study the distribution of the backoff delay in an 802.11 DCF WLAN under saturation conditions. We show that, with our method, the probability that the backoff delay is below a given threshold can be computed accurately and efficiently. Then, we extend our backoff delay distribution model to analyze the end-to-end delay, and propose an admission control algorithm based on this analysis. The proposed algorithm is evaluated in a mixed environment with voice and data stations, and simulation results confirm that it effectively provides voice stations with end-to-end delay guarantees. The algorithm is also evaluated in terms of computational cost and shown to be efficient enough for run-time usage.