Analyzing and Improving the DCF Fairness in Ad hoc Network

In this paper, the impact of physical carrier-sense mechanism on the fairness of the IEEE 802.11DCF MAC protocol in multi-hop Ad hoc networks is investigated, considering that physical carrier-sense range is much lager than communication range. This paper discovers that the IEEE 802.11 DCF MAC protocol may suffers from a great fairness problem because of the carrier interference. To solve this problem, a Collisions and Interferences Aware Backoff (CIAB) algorithm is then proposed. Simulation results show that this algorithm can greatly improve the fairness of the IEEE 802.11 DCF MAC protocol without significantly impairing aggregate throughput in Ad hoc networks.