Proportionally Fair Resource Allocation in Multirate WLANs

Abstract

Since IEEE has a standardized 802.11 protocol for wireless local-area networks (WLANs), significant work has been done to develop rate adaptation algorithms. Most of the rate adaptation algorithms proposed till now are heuristic, suboptimal, and are competitive in nature. Even though these algorithms have the advantage of being implemented in distributed fashion, their throughput performance will be low as these schemes may converge to inefficient Nash equilibrium. On the other hand, users may cooperatively choose their rates so that a social optimum can be achieved, but there are no known algorithms that do rate adaptation cooperatively and can still be implemented in a distributed fashion. In this paper, we design a centralized algorithm that achieves a social optimum (by conducting rate adaptation cooperatively) while guaranteeing proportional fairness. We show that it converges in, at most, N iterations and has time complexity O(N-2), where N is the number of users in the system. Furthermore, we propose a distributed algorithm that also serves the same purpose as the centralized algorithm.