A Maximum Fair Bandwidth Approach for Channel Assignment in Wireless Mesh Networks

Multi-channel multi-radio WMNs are promising solutions for overcoming the limited capacity problem in multi- hop wireless networks. In these WMNs, each mesh router is equipped with multiple radios and each radio operates in a distinct frequency band. Channel assignment is the key issue that should be addressed in these networks. In this paper we propose a channel assignment scheme with the objective of maximizing per-flow bandwidth with fairness consideration to equalize the bandwidth assignment of flows. A novel problem formulation as multi-objective non-linear optimization problem is developed. We propose a heuristic randomized channel assignment algorithm, MFPFB, to obtain an approximate solution. The MFPFB assigns channels based on the interference level experienced by each flow, which is derived from the given traffic pattern and the proposed interference model, DWIG. For a given channel assignment, a simple algorithm allocates bandwidth for each flow. We used numerical and ns-2 simulations to compare our algorithm against others, investigate effect of routing mechanisms and to validate our model. The result indicates an improvement of up to 20% in the effectiveness of bandwidth assignment.