Implementation and evaluation of a combined optimization scheme for routing and channel assignment in wireless mesh networks

We develop an algorithm to optimize routing and channel assignment for multi-channel wireless mesh networks. We apply our proposed algorithm to a cognitive radio system using TV white space channels, which has been developed in previous researches. To maximize the capacity and throughput of such multi-channel mesh networks, conventional algorithms separately deal with two problems, the channel assignment problem and the routing problem. Because the routing and channel assignment affect each other for maximizing the throughput, the real optimal solutions cannot be obtained by such conventional separated optimization approaches. In this paper, we combine those two problems as one optimization problem, to solve the real optimal state of the channel assignment and the routing. We formulate an objective function of the problem by using a new state variable with constraints. We apply an exact algorithm and a heuristic algorithm to our combined problem and show effectiveness of the proposed scheme by comparing their throughput performance with the conventional scheme using exact algorithms. Furthermore, we implement a wireless mesh network running our proposed algorithm using 2.4GHz wireless LAN. Our experimental results show that the proposed scheme has better performance than the conventional separated optimization even in a real system.