WSNp1-5: Analysis of a New 802.11 Distributed Media Access Control Protocol

Many modifications have been proposed in the literature to improve the performance of distributed coordination function (DCF) under congested environments. These improvements are achieved by modifying the contention window reset mechanism used in DCF protocol. However the main drawback with these modifications is the high backoff process overhead. Therefore we recently proposed a new DCF (N-DCF) protocol to reduce backoff process overhead. In this paper, we proposed a throughput model for N-DCF which is applicable for any arbitrary load conditions. The model was verified using NS- 2 simulations. We then compared the performance of N-DCF with the other recently proposed modifications to DCF in the literature. Comparisons have revealed that only N-DCF provides improvement in throughput performance under RTS/CTS access mechanism. Based on our observations, we further proposed two more media access control protocols to improve the performance of DCF protocol in both basic and RTS/CTS access mechanisms. Finally, we compared the performance of our proposed protocols with our original N-DCF protocol.