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.