A mathematical formulation for joint channel assignment and multicast routing in multi-channel multi-radio wireless mesh networks

Multicast routing is generally an efficient mechanism for delivering identical content to a group of receivers. Multicast is also deemed a key enabling service for a wealth of audio and video applications as well as data dissemination protocols over the last-mile backhaul Internet connectivity provided by multi-channel multi-radio wireless mesh networks (MCMR WMNs). Major prior art multicast protocols in these networks center around heuristic or meta-heuristic initiatives in which channel assignment and multicast routing are considered as two separate sub-problems to be solved in sequence. It might even be the cast that the solution for either of these two sub-problems is assumed to be preparatively calculated and given as input to the other. Within this perspective, however, the interplay between the two sub-problems would essentially be ruled out from the computations, resulting in sub-optimal solutions for network configuration. The work in this article is targeted at promoting the adoption of cross-layer design for joint channel assignment and multicast tree construction problem in MCMR WMNs. In the proposed scheme, contrary to the existing methods, these two sub-problems will be solved conjointly and an optimal solution is provided. In particular, a comprehensive cross-optimization framework based on the binary integer programming (BIP) formulation of the problem is presented which also addresses the hidden channel problem in MCMR WMNs. We have, as well, conducted an extensive series of simulation experiments to verify the efficacy of the proposed method. Also, experimental results demonstrate that the proposed method outperforms the genetic algorithm and the simulated annealing based methods proposed by Cheng and Yang (2011) in terms of interference. & 2011 Elsevier Ltd. All rights reserved.