Research Of Network Coding Based On Multipath Routing Protocol For Ad Hoc Networks

Ad hoc network is a kind of wireless mobile networks, which is independent of fixed equipments and can perform self-organizing. Mobile terminals can function as routers and can form any dynamic network topologies through wireless connections. In recent years, many researchers have focused on the improvement of routing protocols in order to better use in the new actual environment based on the characteristics of Ad hoc networks.Traditionally, nodes just route and forward packets. With the increasing of the network load, there will be packet loss and retransmission because of the output queue length limitation, which can cause network congestion and reduce the throughput. However, network coding allows nodes to encode data before forwarding. This technology has the advantage of increasing network throughput, saving bandwidth and balancing link load. The wireless network coding scheme COPE is a new architecture for the unicast traffic scenario. COPE exploits the broadcast nature of nodes and shared the nature of the wireless medium to simplify the coding procedure from the metric operation to an XOR operation, which decreases the compute complexity greatly.The paper applies COPE for Ad Hoc network routing protocol. Based on the typical wireless routing protocol, AOMDV protocol, COPEAOMDV is designed. The new protocol identifies coding opportunities and benefits from them by fording multiple packets in a single transmission. NS2 is used to simulate the COPEAOMDV protocol in this paper. The performance of both routing protocols in several different random topologies is compared in the simulation. The results show that COPEAOMDV can increase the throughput of networks, and also can effectively alleviate the congestion of the wireless networks which uses the AOMDV protocol.