Performance analysis of service differentiation schemes for IEEE 802.11 Wireless LANs in non-saturated conditions

In order to support quality of service (QoS) in 802.11 wireless LAN, current research work as well as the enhanced DCF (EDCF) defined in 802.11e standard, tends to provide differentiated services by varying the parameters of MAC protocol. In this paper, we present an analytical model for performance evaluation of these service differentiation schemes in non-saturated traffic conditions. The analytical results show that neither significant throughput nor packet delay differentiation can be achieved by these schemes when the total load is less than the optimal value, which is quite different from that in saturated conditions. The simulation results validate the analytical model.