WEIGHTED CHANNEL ALLOCATION AND POWER CONTROL FOR SELF-CONFIGURABLE INFRASTRUCTURE WLANS

Abstract

IEEE802.11 WLANs show increasing growth in popularity. Since these networks operate in the unlicensed ISM bands where the number of non-overlapping channels is limited, the growing number of wireless nodes leads to interference. It is well known that the interference leads to degraded performance of WLANs, especially in densely populated areas where the number of overlapping nodes is very large. Channel assignment algorithms have been proposed in recent years, in order to minimize or avoid interference between neighboring access points and hence alleviating the problem. In particular, weighted assignment algorithms have been frequently occurring in the literature. However, the effects of these algorithms are currently not well understood. In this paper, we present results, which show that weighted channel assignment algorithms that do not consider traffic categories can lead to heavy interference among WLANs with delay sensitive traffic, e.g. voice traffic. In order to overcome this, we instead propose a weighted access category channel assignment algorithm (WACCA). We present results from experiments, which show that WACCA achieves a small degree of Interference (DOI) as compared with a greedy algorithm. We also show that there is a tradeoff with convergence time. Furthermore, we propose an integration of WACCA with dynamic transmission power control and show how this combined method produces even more gain.