Research Of Channel Assignment And Routing Algorithm In Multi-radio Multi-channel Wireless Mesh Network

Wireless mesh network has become a potential technology of the next generation wireless communication systems with its high reliability,high bandwidth,low deployment cost,wide coverage,and good scalability.By configuring multiple wireless interfaces in the same node,the multi-radio multi-channel technology can improve the throughput of the network directly and effectively in the wireless mesh network,while increases wireless interference simultaneously.The optimization of routing protocols and channel allocation techniques have a effect on reducing wireless interference and improving network throughput in multi-radio multi-channel wireless mesh network,which has been proved by many studies,but the scarce spectrum resources increase the co-channel interference in the network,causing problems such as capacity drop.In this regards,this thesis focus on channel allocation algorithm and routing algorithm in multi-radio multi-channel wireless mesh network,and proposes a partially overlapping channel allocation algorithm that considers interference avoidance and load balancing.Firstly,the communication interface allocation method based on the Huffman tree is used to connect the interface of the neighbor node.Then,iterative channel allocation is performed on the link according to the wireless interference situation.Finally,the heuristic algorithm is utilized to optimize the link scheduling by assigning interference-free time slots to the high-priority links in turn.The simulation results show that the proposed algorithm can significantly improve network throughput,reduce wireless interference and average packet loss rate,and improve network performance in multi-radio multi-channel wireless mesh network.The channel allocation process may change the network topology,which may have an effect on routing.Therefore,it is necessary to study the routing algorithm based on the channel allocation algorithm.The definition of routing metric in most literature only uses a single metric or considers one type of interference: interflow or intraflow,and cannot accurately measure the traffic in the network.Thus,on the basis of improving the channel allocation algorithm,this thesis proposes a new routing metric to select the optimal path to access the Internet considering the problem of the gateway and routing selection in multi-radio multi-channel wireless mesh network.The proposed metric considers both intra-flow and inter-flow interference,packet loss rate and gateway load,uses a weighted combination of multiple routing metrics,which significantly reduces delay and packet loss.In order to reduce the adverse effects of frequent routing changes on network performance,this thesis also proposes a path switching strategy.The simulation results demonstrate that the proposed algorithm improves the network throughput effectively.