Enhancement of IEEE 802.11b Distributed Coordination Function to Reduce Packet Retransmission

In this paper, we provide an extended model for analytical analysis of an IEEE 802.11 Wireless Local Area Networks (WLANs) that accommodates the nonsaturated operation of the network, homogeneous traffic and the noisy wireless channel. We propose a modified Distributed Coordination Function (DCF) and model it with a discrete time Markov chain, with the aim of improving the throughput when stations are nonsaturated. Through the analysis results the modified DCF scheme is proved that stations achieve higher throughput compared with the presently existed IEEE 802.11 DCF. However, to the best of the authors' knowledge, there is no previous works that enhance the performance of the DCF under noisy wireless channel. When the probability of error is high, the modified DCF ensures high throughput and low packet delay by reducing the channel idle time under the low traffic in the network.