Delay Analysis of IEEE 802.11 DCF with Back-off Suspension

We present in this paper an analytical model that accounts for the back-off suspension in DCF mode while evaluating delay performance of IEEE 802.11 MAC layer. Our work is based on the Bianchi's model where the performance of 802.11 MAC layer is computed using a discrete time Markov chain. The contribution of this work is to take the back-off suspensions into considerations and derive a more accurate delay analysis model of the IEEE 802.11 MAC protocol based on Markov model. We evaluate our analysis model through simulation compared to P. Chatzimisios' model. Simulation result shows that without considering the back-off suspension as specified in the current standard, current major models have super-estimated the saturation delay performance of the IEEE 802.11 MAC protocol, especially when the number of stations in a basic service set is increasing.