Research On Joint Routing Metric And Channel Assignment In Multi-rate Wireless Mesh Networks

The rapid development of wireless communication technology and mobile Internet has brought unprecedented change to people’s daily life, the requirement of network quality has also improved. Wireless Mesh Networks(WMN) have been widely used in a variety of scenarios because of its low cost, ease of deployment, high speed, flexibility and other characteristics. WMN has become an important communication technology to build a wireless network, and is also an efficient and reasonable choice.The current network protocols are supported by a variety of transmission rates, it’s a great significance to improve the overall performance of the network by adequate and reasonable use of multi-rate transmission capacity and available rate resources. In multi-rate WMN, there is a performance anomaly when a low-rate link and a high-rate link contention with a common channel, the high-rate link performance will be severely affected by the low rate link, and lead to the high-rate link can’t full play its high rate advantage. There are a large number of scholars studied multi-rate network performance anomalies, had proposed a variety of routing metrics and channel allocation algorithm to solve the transmission problems in multi-rate network. However, the existing multi-rate network routing metrics and channel allocation algorithm did not consider the interaction between them, can’t really reflect the actual situation of the network. So it has important significance and value to alleviate multi-rate network performance anomalies and improve overall network performance by study the joint routing metric and the channel allocation algorithm.In this paper, we proposes a joint Multi-rate Dijkstra’s min-Cost routing metric and Rate Separated channel assignment algorithm(MDC-RS) in multi-rate WMN. Considering the relationship and influence between routing metric and channel assignment. Take full advantage of multi-rate transmission capacity in the process of routing metric, get the minimum cost path and corresponding transmission rate of nodes by computational the cost at different rates. And combine with the characteristics of WMN, traverse all the nodes in the network by find a way from destination node to source node. On the basis of MDC routing metric, distribute links with different rates on different channels according to compute the weight of the node throughput, achieve separation of link rates to avoid direct competition between the different rate links. Solve the performance anomaly on the basis of find out the actual situation of network.To further enhance the overall network performance, we proposes a joint Multi-path Multi-rate Dijkstra’s min-Cost routing metric and Rate Separated Partially Overlapped channel assignment(MMDC-RSPO) algorithm on the basis of MDC-RS joint algorithm. By multi-path routing metric, it is possible to obtain a plurality of available forwarding nodes in the transmission rate. It’s taking the load status of nodes into account when obtaining the multi-path cost to achieve network load balancing. On the basis of MMDC, we proposed partially overlapping channel assignment algorithm in multi-rate environment aiming at the restricting of the number of available orthogonal channels. The rate interference weight of link is calculated on different channels. Choose available partially overlapping channels for links while achieving the rate separation. Make full use of the available channel resources to further enhance network performance.NS-3 simulation results indicate that, the proposed algorithm MDC-RS and MMDC-RSPO can significantly improve the network throughput, and decrease the average end-to-end delay as well as packet loss probability.