Optimal Performance Study of IEEE 802.11 DCF with Contention Window

The IEEE 802.11 protocol has achieved worldwide acceptance with WLANs with minimum management and maintenance costs. In order to maximize the throughput, stations had to spend many times to find out the best contention window. In this paper, we modified the Wang's model and took account of the freezing of the back off counter when channel is busy. In the modified model, it is easily to obtain the optimal contention window for a given network scale. The selection of optimal contention window is just based on the network scales. Simulation results showed that the throughput is the same as Wang's. But, the optimal contention window is less than Wang's.