Abstract
Wireless Mesh Networks (WMNs) based on commodity 802.11 radios exhibit extreme unfairness, including starvation, in the presence of backlogged traffic sources. While the underlying reasons for this performance degradation are well understood, yet only a few of the proposed solutions are compatible with the current generation of closed 802.11 firmware/hardware. Most existing proposals limit sources to their fair share through a distributed rate control mechanism, in the process incurring a significant overhead to enable such local computation of fair rates.
In prior work we validated the feasibility of centralized rate control in WMNs, assuming knowledge of network topology and link interference. In this work we remove this requirement and propose a zero-overhead centralized rate controller. This controller can be implemented at traffic aggregation points such as gateway routers. Its response is driven by a feedback-based mechanism, allowing it to, adapt to changes in network and traffic conditions. Simulations show that our controller can improve the fairness metrics by a factor of 3 over networks without any rate control, and is within 2% of the fairness metrics achieved by a centralized controller with omniscient knowledge of network topology and link interference.