Abstract

The traffic load of wireless LANs is often unevenly distributed among the access points (APs), which results in unfair bandwidth allocation among Mobile Users. We argue that the load imbalance and consequent unfair bandwidth allocation can be greatly reduced by intelligent association control. In this paper, we present an efficient solution to determine the user-AP associations for bandwidth allocation. We show the strong correlation between fairness and load balancing, which enables us to use load-balancing techniques for obtaining optimal fair bandwidth allocation. As this problem is NP-hard, we devise algorithms that achieve constant factor approximation. In our algorithms, we first compute a distributed association solution, in which users can be associated with multiple APs simultaneously with variable bandwidth. This solution guarantees the fairest bandwidth allocation in terms of Max-min fairness; we obtain the integral solution from the fractional solution by distributed association algorithm. We also consider time fairness and present a polynomial-time algorithm for optimal integral solution and it is ensure that zero percent data loss

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