Ad Hoc Network Routing Protocols And Simulation

Ad Hoc network composed of mobile nodes with wireless communication device are typically characterized by their multi-hop, self-organized and un-center. With its highly flexibility, Ad Hoc network will be widely used in the fields of military, civil and various environments which the fixed communication infrastructure are difficult to set up. However, the traditional internet routing protocol can not meet the demand of ad hoc network because the topology of which frequently changes. So the routing protocols are always an important research field of ad hoc network.In this thesis, the basic concepts, the classification and several typical routing algorithm of ad hoc routing protocols are briefly introduced. And three commonly used routing protocols, DSDV, AODV and DSR, are analyzed and compared with the simulation tool NS2. And it is concluded that on-demand routing protocol is more suitable for Ad Hoc network than table driven routing protocol. Then AODV is expected to be the further study object due to that it combines the advantages of DSR and DSDV.After deeply examining AODV algorithm of on-demand routing protocols, an improved algorithm called FR-AODV is proposed in which the upstream node of the fail link could fully use the information of its indirect neighbor to repair the broken link. And the simulation demonstrates that the packet delivery fraction and the average end-end delay of FR-AODV are significantly improved, yet the routing overhead just increases a little.In addition, focuses on the problem of network division and large end-end delay due to the heavy load and fast energy consuming of the center nodes which brings by the minimum hops routing metric method in AODV, another improved algorithm called LBEA-AODV based on the information of load and energy is proposed. When a new route is setup in LBEA-AODV, the destination node would choose a route which the overall load is comparatively low and the most minimum remaining energy of the node in the link is comparatively high to alleviate the heavy load of the center node. Meanwhile, LBEA-AODV wouldn't choose the heavy load node to be a medium node in the route setup period, and in the route maintaining period, the route rebuild would be started when the remaining energy of the node in an active link is below the dangerous value. The result of the simulation shows that the packet delivery...