The Research Of Channel Assignment Algorithms For Wireless Mesh Networks

With the rapid development of information in the world, the user requirement forthe network communication is increasing accordingly. The Wireless Mesh Network isa new emerging wireless broadband technology for the last-mile Internet access withmany advantages such as low cost, high capacity and efficiency. Its applications areprosperous and research about it becomes a hotspot in the field of computer networks.The broadcasting characteristic of wireless communication leads to the co-channelinterference among the adjacent links, and reduces the network throughputaccordingly. Multi-channel technology allows simultaneous transmission and help toimprove the network throughput. However, an improper channel assignment canresult in network partition or link failure. The network performance is deeplyinfluenced while utilizing the limited channel resource. The channel assignmentproblem is NP-hard. In this paper we have developed and designed algorithms for thisproblem based on the topology preservation.(1) The paper has researched the link-based channel assignment problem. It isimpossible to find the optimal solution in polynomial time, and a DPSO-based isproposed in which the particle evolution is used to find the sub-optimal solution. Thepaper also has proposed a centralized heuristic algorithm with time complexion asO(K*|E|2). And a distributed version is given too. Finally the paper has showed thatthe proposed algorithms can be quickly used in case that traffic load is un-even, whichshows its robustness and flexibility.(2) The paper has researched the node-based channel assignment, in which severallinks are feasible between a pair of neighbor nodes. An ILP-based algorithm isproposed to find the optimal solution. A DPSO-based algorithm is also introduced inthis paper, in which particle evolution is used to find the sub-optimal solution. Theperformance is analyzed by simulation. This paper also discussed the case withun-even traffic, and analyzed the strategy to improve the network throughput byutilizing the radios on the nodes.