Research Of Channel Assignment And Routing Protocol In Wireless Mesh Networks

With the rapid development of mobile Internet technology and the widespread use of WLAN, these issues in WLAN attract more and more attention such as coverage gaps and lack of access ability and so on. The wireless Mesh Network has many features such as multi-hop, self-organizing, self-configuring and a wide range of coverage,these features indicate it can be a good solution to these issues in WLAN. So wireless Mesh technology is booming in recent years, but with the research of wireless Mesh technology gradually deepening, these problems in Mesh exposed more and more at the same time, Such as a sharp decline of performance after multi-hop transmission, hard to guarantee Qos and low utilization efficiency of wireless channel resources. This paper researches the channel assignment and routing algorithm in wireless Mesh network to solve these problems and improves the performance of wireless Mesh network.Firstly, links suffered by strong channel interference and lead to poor transmission performance in single-radio single-channel wireless Mesh network, this paper uses multi-radio multi-channel technology to enhance network performance and designs a channel assignment alogrithm based multi-rate network called LMRFCA(Link Multi-Rate Fixed Channel Assignment). The algorithm takes into account a link multi-rate network which is more similar to actual Mesh environment and establishes a link multi-rate network topology based on the analysis of the traffic characteristics in wireless Mesh backhaul network and divides links into different levels, then allocates channel to these links by heuristic algorithm, at the same time consideres the performance anomaly problem which caused by multi-rate link, full use of channel allocation and network resources to reduce the loss of bandwith caused by performance anomaly problem and improves network performance.Then, to optimize the routing alogrithm in multi-radio multi-channel multi-rate wireless Mesh network, this paper designs a multi-radio multi-channel multi-rate routing algorithm MMM-HWMP(Multi-radio Multi-channel Multi-rate HWMP) based on original HWMP, the algorithm researches the routing metric and channel switch mechanism mainly. The paper analyses the channel interfernence and multi-rate issues, and designs an apposite routing metric called MRM(Multi-rate Routing Metric) which considers interflow interference and intraflow interference, then proposes a channel switch mechanism based on the construction of a bidirectional transmission path, enhances the flexibility and anti-interference ability of the network effectively.Finally, the paper sets up different network scenes to simulate and analyses the performance of these algorithms on NS3 simulation platform, and compares with some classical alogrithms. The simulation results of channel assignment alogrithms show that the total network throughput of LMRFCA is 13% higher than that of C-HYA and 37% higher than that of MINCI under different transmission rates; 11% higher than that of C-HYA, 29% higher than that of MINCI under different transmission flow. In the routing alogrithms simulation, compares to HWMP-P and HWMP-R, the total network throughput of MMM-HWMP could be improved by a factor of 6% above and the delay of MMM-HWMP could be decreased by a factor of 29% above both under different transmission rates and flow.