Fairness issues in multihop wireless ad hoc networks

HE JUN

Publication

Fairness issues in multihop wireless ad hoc networks

HE JUN

Abstract

In this thesis, we investigate the fairness of bandwidth allocation in multihop wireless ad hoc networks (MANETs) at two levels: the MAC/link layer and the network layer with focus on MAC/link layer fairness. We demonstrate that IEEE 802.11 operating in a MANET could suffer from a severe fairness problem. To remedy the fairness problem, a new protocol EHATDMA (extended hybrid asynchronous time division multiple access) is proposed. Simulation results show that EHATDMA strikes a good balance between throughput and fairness. In addition, we identify the non-work-conserving mechanism as the most important mechanism affecting fairness. A three-dimensional Markov model is proposed to further analyze the throughput and fairness properties of IEEE 802.11 in MANETs. The model confirms the conclusion that non-work-conserving principles will MAC/link layer fairness. Our preliminary results indicate that a fair MAC protocol also improves fairness as well as other performance aspects of TCP flows in MANETs.