Abstract
The classical max-min rate allocation is a commonly used fairness criterion in wired networks. Its implications, however, are not well understood in the context of wireless networks. In this paper we outline various considerations that govern max-min rate allocation in 802.11-based Wireless Mesh Networks (WMNs). Such considerations assume importance because WMNs exhibit extreme unfairness, including starvation, with backlogged TCP flows. We show that it is possible to achieve approximate max-min rate allocation simply by rate limiting the aggregate capacity of the network. Such rate limiting can be performed centrally at traffic aggregation points. In this context we propose a rate-based scheduler that can be implemented at gateway routers. Simulations show that our proposed controller can improve the fairness index by over two-fold compared with networks without any rate limiting, while maintaining upwards of 80% network throughput achievable with a perfect scheduler.