Research On Channel Assignment And Routing Metric Algorithm For Multi-radio Multi-channel Wireless Mesh Network

Wireless Mesh Networks(WMN)are an important part of wireless communication networks.The future application scenarios are broad and have high research value.Improving wireless network performance has always been at the forefront of academic research.Channel assignment scheme and routing metrics algorithm can improve network performance,and thus become a research hotspot at home and abroad.The reasonable channel assignment design makes full use of the channel resources in the spectrum,reduces the co-channel interference existing in the traditional wireless communication network,improves the network throughput and reduces the delay.A well-designed routing strategy can improve packet forwarding efficiency and reduce data stream interference in the link.Based on the analysis of the research status at home and abroad,this paper focuses on how to properly allocate channels in WMN and rationally design routing metrics to improve network performance.The main research results are as follows:(1)Propose a centralized channel assignment algorithm(POCAC).The goal of the channel assignment algorithm is to minimize or even eliminate interference present in the channel.Research shows that the use of Partially Overlapped Channels(POCs)in a multi-channel environment can effectively reduce the channel interference and improve the parallel transmission capability of the network.However,the use of POCs for transmission can lead to a variety of interferences that cannot be avoided with a simple RTS/CTS mechanism.A centralized channel assignment algorithm(POCAC)is proposed to solve the problem of incomplete factors in the current channel assignment strategy.By designing the link weight function,the channel order is assigned to the load link.First,the unloaded channel is allocated for the high-load heavy interference link,and then the interference channel is supplemented for the remaining link.The POCAC algorithm is used to preferentially allocate the link with the least interference according to the network interference until all the links complete the channel assignment.Simulation experiments show that the POCAC algorithm reduces the average packet loss rate and reduces the end-to-end delay compared with the traditional channel assignment algorithm i-POCA.(2)Propose a new routing metric LP-IDA.A reasonable routing metric design strategy improves network performance by improving packet forwarding efficiency.Since the packet is affected by many factors in the forwarding process,the design of the routing metric needs to consider many factors,generally considering the path length and the data stream interference during the transmission process.Recent studies have shown that if the routing metric only considers the path length and data stream interference,the network performance will decrease significantly as the network size increases.Because delay perception and packet difference in large-scale networks also affect packet forwarding efficiency,which affects network performance.A new routing metric LP-IDA is proposed for traditional routing metrics considering only the shortest path and interference.The route metric comprehensively considers delay and interference,and sets priorities for packets to implement packet differentiated transmission.The link quality is guaranteed for real-time communication,and the packet forwarding avoids the high-speed link with less interference in the heavy interference region selection.The experimental results show that LP-IDA has good network performance in terms of average end-to-end delay compared to other routing metrics under guaranteed throughput.