Research On Routing Technology In MANET

Differentiating from other existing networks, mobile ad hoc network consists of mobile hosts, which connects by wireless to form a temporary, independent local network. Without infrastructure and special router, every node in mobile ad hoc network is a terminal as well as a router. Multiple hops are needed while data is transmitted from a source node to a destination node. With development of mobile ad hoc networks changing from military to civilian use, more and more applications are jointed into mobile ad hoc networks. Router losing makes the routing unreliable and instable, especially in the case of multi-media application due to the intermediate nodes moving outside network. The resolve of these difficulties becomes the key of network study.In this dissertation, a Multiple Next Hop routing algorithm is first proposed, which improves single path routing algorithm. Under multimedia environment, the main reason of packets loss in mobile ad hoc network is due to the congestion. The problem may be resolved through transferring some data from the congestion path to other idle path. With the on-demand way and flat routing structure, algorithm MNH introduces data packets into backup routing when main routing throughput goes into saturation point. Feasibility analyzing and simulation for the algorithm shows that MNH can revive throughput into knee point and increase reliability of routing.Second, a quick switching routing protocol (QSRP) is proposed. It adopts multi-path routing structure for increasing performance of routing resumption as a routing loss and decreasing average transmission delay time of packet. The method of QSRP is based on the concept that the main routing nodes hold many spare routings. When the main routing loses, packets are switched into a switching routing for forwarding; While if the switching routing loses, the others can instead of it to transmission of packets. Simulation for QSRP shows that there is a lower transmission delay, fewer of controlling overhead and high rate of packets...