Research On Ad Hoc Routing Protocols And Performance Optimization

Ad Hoc network is a distributed wireless multi-hop network with a group of routing nodes. It is a new type of wireless networks which can organize provisionally without the infrastructure. Utilizing its own wireless transceiver, the nodes in networks can exchange information and have the capability of routing and forwarding. Therefore, the routing protocol is one of the important components in Ad Hoc network.Being typical on-demand routing protocol, AODV(Ad Hoc On-Demand Distance Vector) routing protocol has been widely used for its excellent performance in Ad Hoc network. The number of hop is the only consideration during the forming of the route, so the network lifetime and throughput performance are not optimized. AODV protocol, therefore, has certain limitations in energy-constrained or multimedia message transmission and other applications. This thesis introduces the QoS-AODV(Quality Of Service Ad Hoc On-Demand Distance Vector Routing) protocol based on AODV protocol to improve network performance. Using the idea of QoS, the QoS-AODV protocol integrates the energy consumption and the load of the route to establish the cost function to complete the route discovery. Meanwhile, the QoS-AODV protocol uses the average dynamic residual energy algorithm to optimize the forwarding mechanism of the intermediate nodes. So the large energy consumption and heavy loaded nodes can be avoided in QoS-AODV protocol, which achieve the feasibility of optimizing the destination node routing mechanism and the intermediate nodes forwarding mechanism at the same time. Compared with AODV protocol and the modified AODV protocol, it can be shown from the simulation results that QoS-AODV protocol can significantly extend the lifetime of the network, improve the network throughput while reducing the death rate of the node and node energy consumption.