Joint Transmit Power Control and Rate Adaptation for Wireless LANs

Wireless local area networks (WLANs) are widely deployed recently. But many basic service sets (BSSs) nearby have to share a common channel due to the limitation in the spectrum resource. To get higher throughput with newly deployed access points (APs), it is necessary to improve spatial reuse of the channels by transmit power control (TPC). The achievable throughput, however, heavily depends on other factors such as rate adaptation (RA). Moreover, TPC without careful design may lead to asymmetric links and degrade fairness. In this paper, we jointly design TPC and RA to further improve total throughput of WLANs, and suggest (i) choosing power for each BSS by maximizing throughput which takes tradeoff between transmit rate and spatial reuse of channels, and, (ii) avoiding potential asymmetric links by explicit coordination among APs: each BSS uses almost the same power as its co-channel neighbors while BSSs far from each other may use different power levels as required. Extensive simulation evaluations confirm that the proposed scheme can greatly improve total throughput of dense WLANs, meanwhile fairness is retained.