A fair distributed congestion-aware power control algorithm for IEEE802.11 based networks

It has been a common practice in wireless multihop networks to transmit at the lowest power at which the network still remains connected. Although this strategy has been proved to improve throughput-capacity performance as the number of nodes tend to infinity, it might have a significant effect on deteriorating both throughput and delay performance in many practical situations. The main culprit is the relatively low spatial reuse one can attain in typical IEEE 802.11 network topologies, even when operating at the lowest possible power levels. This, in turn, is due to the rather conservative 2:1 carrier-sensing/transmission range adopted in most implementations of the protocol. In this paper, we prove that transmitting at the per-link-minimality condition (employing just enough power to reach the intended receiver in one hop) is optimal from a delay-throughput perspective in most network sizes of interest. Since transmitting at the per-link-minimality condition gives rise to some unfairness under certain traffic patterns, we propose a fair distributed power control algorithm that gives an enhanced throughput-delay performance whilst keeping an eye on energy consumption.