Research And Improvement Of More Opportunistic Routing Protocol Basrd On Network Coding

Since entering the twenty-first century, with the extensive use of various mobile devices, wireless network communication technology is developing more and more faster. Due to the increasing demands of the users on the bandwidth and communication quality of the communication network, a variety of new network communication technology continues to appear. As a new type of wireless communication network, wireless Mesh network has many advantages such as flexible of networks, low deployment cost, strong adaptability, high stability and so on, it has become an important broadband wireless access technology and also attracted many researchers’ attention. The traditional wireless Mesh network routing protocol design mainly from the wired network, and cannot be fully applicable to the wireless Mesh network. As new technology in wireless communication field, both network coding and opportunistic routing can use the particularity of wireless broadcast channel effectively, so it bring about new methods for the design of wireless mesh network routing protocol. Now it has become one of hotspots in the field of wireless mesh networks. The research content of this paper mainly focuses on the classic MORE opportunistic routing protocol. The main contents of this paper include:First we introduce the basic theoretical knowledge of this paper, which include the basic principle of wireless Mesh network such as network structure, classification and main application scenarios. Then describes the basic concept of network coding and opportunistic routing, core ideas and work process, and mainly analyzes the working process of the classic MORE opportunistic routing protocol, which lays a theoretical foundation for the following work.Then we analyzed the problem of the number of candidate forwarding nodes on network performance, and propose a new method to optimizing the number of forwarding nodes based on distance(DBNCO). This method comprehensively considers the distance from the current node to the destination, the density of the network and the number of neighbor nodes in the current node to set corresponding number of candidate forwarding nodes for each node in the data packet forwarding. The purpose is to reduce the number of candidate forwarding nodes in the network effectively while ensure data transmission success rate, so as to reduce the control overhead and improve the performance of the network.Last, in order to solve the problem of high transmission delay of MORE protocol, some improvement measures are put forward, which mainly includes two aspects:In terms of network coding, we introduce partial network coding scheme to replace the full network coding scheme in MORE protocol to improve the efficiency of coding and decoding, so as to reduce the encoding and decoding of delay. In terms of opportunistic routing, in order to improve the efficiency of data transmission, we put forward a new candidate forwarder selection metrics ETD(Expected Transmission Delay), the forwarding candidate nodes to the destination with lower delay has higher priority, which makes data forwarding along with the link which has lower delay as far as possible, so as to improve the data transmission efficiency and reduce the network delay.