The Research Of Opportunistic Routing Strategy Based On Network Coding In Wireless Mesh Network

Wireless mesh network is a new type of network based on wireless local area networks and ad-hoc networks, it has broad application prospects in many research fields. Wireless mesh network combines of the superiorities of wireless local area networks and wireless ad-hoc networks. It can make multiple wireless access point cooperate to each other, has the characteristic of self-organization, easy extension, and good maintenance. In order to give full play to the performance of wireless mesh networks, routing technology in network layer is the key of research. Thus, how to design routing protocols with high qualities to ensure the reliability of data transmission and the performance of network is a key problem that scholars at home and abroad focus on.Network coding and opportunity routing technology both offer a new idea to design routing protocols. Network coding is different from the traditional way of data transmission, the node has not only the traditional store and forward function, but also the ability of processing packets before sending them out, which can reduce the number of transmission, and improve the network throughput. Opportunistic routing is put forward to break the traditional transmission mode that nodes send data to the changeless next-hop node. It can make full use of the radio characteristics of wireless channel, through multiple candidate forwarding nodes compete with each other to choose the best forwarding nodes as a potential "next hop" which can improve the reliability of data transmission. Currently, many scholars at home and abroad have done a lot of researches of how to combine network coding and opportunistic routing. However, the routing strategy combining opportunistic routing and network coding is so very mature that it still has a long way to go.In this paper, we analyze the COPE protocol and put forward a new opportunistic touting strategy(OC-COPE) based on code optimization. The OC-COPE strategy can choose the forward node with high coding opportunity by calculating the value of coding opportunity of the node, and can use partial network coding to reduce the complexity of coding. Comparing with the COPE protocol, the simulation results show that, this strategy can improve the network throughput and data delivery success rate and can also reduce the end-to-end delay.Then, focused on the fast energy consumption and the problem of energy limited nodes in mesh network, this thesis proposes a new algorithm OE-COPE. In this routing protocol, we design a new routing metric OECAM, which takes coding opportunistic, energy consumption and the residual energy of node into consideration in selecting a high quality node as a forwarding node. The metric can delay the time of nodes’ death, increase the coding opportunity and the overall performance of the network. The experimental results show that this mechanism can greatly optimize the energy consumption and improve network throughput.