An improved analytical model for WLANs under unsaturated traffic conditions

In this paper, an improved IEEE 802.11 WLAN analytical model under unsaturated traffic conditions was proposed, which adapts existing MAC distributed coordination function (DCF) models to consider all the states. To achieve that, two special states were added, one is the idle state, which means the MAC queue is empty, and the other is D state, which means if the medium is sensed to be idle for a time interval greater than the DIFS, the station proceeds with the packet transmission. Consequently, the improved IEEE 802.11 WLAN can be used to study the average packet delay in MAC layer. Simulation results indicate that this model is more accurate.