Research On Channel Assignment In Multi-channel Wireless Mesh Networks

Wireless Mesh network is also known as wireless multi-hop networks. It is a new type of wireless network architecture and a very competitive solution which wireless terminal use to access to the Internet. It has lots of advantages such as dynamic self-organizing, self-configuration, low cost, easy maintenance, operational stability, good scalability, network capacity and so on. It has gradually become a research hotspot of broadband wireless communications.With the development of wireless network and mobile internet services, the number of users increases rapidly and the user demand for bandwidth is also rising. As a result, increasing the network capacity is to be a key issue with the development of Wireless Mesh Network. To solve this problem, using multi-channel is a simple and effective way. If we can use multiple channels effective, it can greatly improve the throughput of Wireless Mesh Networks. The goal of this article is to improve network throughput, we do a lot of researches on the channel assignment in Wireless Mesh Network.First, this article describes the basic knowledge of Wireless Mesh network, and analyses the constraints and challenges of channel assignment in WMN. We also summarize the strengths and weaknesses of the channel assignment algorithm. In the wireless mesh network without gateway, its business is mainly between the end-users. This paper proposes an integer linear programming ILP model. A channel assignment problem can be transformed into a ILP model, and the model’s goal is to minimize network interference, which is measured as the number of link pairs which are interference with each other. The ILP model can be used to solve the optimal channel assignment and guide the implementation of small networks.Second, the time to solve ILP model is growing as exponential rates, so it can only be used for small networks ILP model. To solve this problem, this paper has proposed a centralized channel allocation algorithm based on link layer optimum. The algorithm for the business model is the business between the Mesh end users. The goal of the algorithm which is the same as ILP is to minimize network interference. Then, through the NS2simulation, it proved that the algorithm can effectively improve the network throughput. This algorithm can be applied to practical large-scale networks.Third, most of the business is from the gateway or to the gateway in the wireless mesh networks which contains gateways. Therefore, the gateway may result in several problems such as hot spots and links. The paper considers these two issues jointly and proposes a centralized quasi-static channel assignment algorithm based on node rank. The algorithm’s goal is to effectively avoid the bottleneck node of each link and balance the traffic flow between the links so that it can increase the network throughput. Through multiple scenarios of NS2simulation experiments, the algorithm can effectively improve the network throughput.Finally, the main work of the full paper is summarized, and lots of work need to be further researched and improved is proposed.