Analysis of IEEE 802.11 non-saturated DCF by matrix analytic methods

In the IEEE 802.11 MAC layer protocol, the basic access method is the Distributed Coordination Function based on the CSMA/CA. In this paper, we investigate the analytic performance of IEEE 802.11 DCF in the non-saturation mode. We assume that there is a fixed number n of competing stations and the packet arrival process to each station is a Poisson process. We model IEEE 802.11 DCF in non-saturation mode by a 3-dimensional Markov chain and derive the steady state probability of the Markov chain by applying the matrix analytic method. We obtain the probability generating function of Head-of-Line delay, non-saturation throughput and packet loss probability. Our results can be used for finding the optimal number of stations that can be accommodated while satisfying a given QoS requirement.