A Simple Adaptive p-persistent MAC Scheme for Service Differentiation and Maximum Channel Utilization

In this paper, we propose an adaptive p-persistent MAC scheme, named QDA-MAC (QoS differentiation based adaptive MAC scheme), for WLAN to maximize the channel utilization and provide the service differentiation among different traffic stations. Specifically, different from the previous works, the proposed scheme does not need to estimate the number of active stations for each priority class and still achieves the channel utilization close to its optimal value by exploiting a new parameter, persistent factor, whose optimal value can dynamically follow the change of the load based on a simple estimation of the network status. At the same time, the transmission probability of each priority class can be updated by optimal persistent factor. Simulation and numerical results show that QDA-MAC can achieve much higher channel utilization and shorter delay than standard IEEE 802.11 DCF and IEEE 802.11e EDCA in all different WLAN environments. Key-Words: QoS differentiation; p-persistent; persistent factor; adaptive scheme; transmission attempt