Sensitivity of the IEEE 802.11b MAC protocol performance to the various protocol parameters

The basis of the IEEE 802.11 MAC protocol is the distributed coordination function (DCF), which is a carrier sense multiple access system with collision avoidance (CSMA/CA) and binary slotted exponential back-off. We examine the throughput and delay characteristics of the DCF basic access mechanism for finite loads with different minimum back-off window size and traffic conditions. Further, studies have been made on the sensitivity of the MAC layer protocol performance to the propagation delay. Simulation results show that the average throughput and average packet delay are highly sensitive to initial back-off window size, the payload size and the number of stations in the network. The results can be used to decide the protocol parameters required to achieve optimum performance under a particular network loading condition.