A Tree Topology Routing Algorithm With Multi-channel In Wireless Mesh Networks

The Wireless Mesh Network is a new type of broadband wireless network. It is a high-capacity and high-speed distributed network. It has many advantages, such as transmission reliability, good scalability and low cost and so on. Wireless Mesh Network is usually used for broadband Internet access and expanded the coverage of wireless LAN. It has become a new solution to the "last-mile" bottleneck in the wireless access problem. Nodes in WMN are basically static, so that the network topology is not frequently changeable. The network traffic flows to the wired network mainly through the gateway nodes, each Mesh node needs to quickly find at least one path to reach the gateway node, logically, which forms some trees whose roots are the gateway nodes.As more and more users access to a wireless mesh network, the network throughput declines rapidly. It is a major factor that restricts the wireless Mesh network works as a backbone network.In this paper, we analyze the main difficulties of the expansion in WMN as well as the advantages of multi-interface multi-channel network capacity and multi-interface multi-channel wireless Mesh network architecture. The main design issues of Multi-Channel Wireless Mesh Networks are channel assignment and routing. We propose a new quality standard ETTch which can be used to assessment and assignment of the available channel in every single link. ETTch is based on existing quality standard ETT (Expected Transmission Time). The channel usage in interference range of the link is considered and the probability of channel interference of a node is calculated. It is the product of ETT in non-interference state and the interfering probability sum of all nodes, it is expectative transmission time of the single-link with channel ch. The quality standard ETTch of link is used during building tree topology when the selection of parent node and channel allocation is considered.Finally, the NS2 simulation software is used to simulate the performance of spanning tree routing algorithm with multi-channel. The results are compared with the AODV in the aspects of network throughput, end to end delay and so on. Analysis results show that this routing algorithm has significant advantages in terms of network throughput and end to end delay to AODV.