A Fair Capacity Distribution Framework for Wireless Networks with Contention-based Medium Access

This paper presents a network-triggered feedback control framework for addressing an inherent hop-unfairness in random access wireless networks, it is experimentally shown that when multiple flows with varying hop-counts compete for wireless bandwidth, the shorter flows can consume an unfair share of the total bandwidth by diverting capacity from longer hop flows. Experimentally we also demonstrate that this effect is not mitigated by the end-to-end feedback mechanism used by rate adaptive transport protocols such as TCP. The goal of this paper is to devise an alternative feedback mechanism that can alleviate this problem of unfair capacity distribution, by introducing a hop-count independent feedback propagation mechanism. This has been accomplished by a network-triggered framework that, unlike TCP, relies on network generated feedbacks for application data rate adaptations. The proposed framework is developed using the ad hoc on-demand distance vector (AODV) routing protocol and is characterized using NS-2 network simulator. Experimental results demonstrate that the proposed mechanism can alleviate the described hop-unfairness problem to a great extent by trading the overall network capacity. Performance of the framework is evaluated for a large number of scenarios and is compared with optimal results, when feasible