Improving the performance of power-aware multi-rate IEEE 802.11 in multihop wireless networks

Abstract

In multihop, multi-rate wireless networks, simultaneous transmissions can interfere with one another to impair the transmission quality and prevent correct frame reception. Achieving high network performance (e.g. throughout and energy consumption) in such networks therefore requires a balance between the spectrum spatial reuse and the transmission quality. To achieve this trade-off, a decentralised control algorithm is proposed that allows a sender–receiver pair, using the IEEE 802.11 four-way access method, to dynamically adjust the transmit power and rate for their frames according to the level of interference in the network. Specifically, the scheme is based on the interplay between two approaches: physical carrier sensing and virtual carrier sensing approach to achieve this optimal trade-off. The algorithm outlines the rules for performing power and rate assignment so that higher performance is obtained. A realistic analytical model is presented to study the performance of the proposed heuristic; analytical results show that the algorithm proposed by the authors, indeed, finds the balance between spatial reuse and transmission quality through its appropriate search for the suitable transmission parameters. Simulation results for different topologies are used to demonstrate the significant throughput and energy gains that can be obtained by the proposed scheme.