Improving the Throughput Performance of IEEE 802.11 Distributed Coordination Function

Distributed coordination function (DCF) is the basis protocol for IEEE 802.11 standard wireless local area networks. It is based on carrier sense multilple access with collision avoidance (CSMA/CA) mechanism. DCF uses backoff process to avoid collisions on the wireless channel. The main drawback in DCF is that packets have to spend more time in the backoff process which is an additional overhead to their transmission time. The channel is rendered idle when all the stations defer their transmissions due to their backoff process. Therefore the channel utilization and the total throughput on the channel can be improved by reducing the average time spent by the packets in the backoff process. In this paper, we present our proposed modification to the original IEEE 802.11 standard DCF protocol so that the channel utilization can be improved with successful packet transmissions and thereby achieve higher throughput performance. We studied the performance of the proposed media access protocol (PMAP) both numerically and through simulations using NS-2 network simulator. Results showed that PMAP achieves considerable improvement in the throughput performance