Improve Aodv Protocol In The Two-hop Topology Environment

With the development of science and technology,portable computer and palmtop computer are increasingly prevalent,and the wireless communication technology develops promptly.It needs some communication technology that needn't depend on any network facility erected before hand.Then Ad Hoc network emerges as the times require.Ad hoe network is one special kind of mobile networks that don't need fixed base station. It's a self-creation,self-organization and self-supervisory network that formed by the cooperation of a boodle of autonomic wireless nodes or terminals .The route mechanism of Ad Hoc network should conform to three basic features:the population density of mobile node,the topology of nodes,and the operating mode of network. There are two kind of routing protocols for Ad Hoc network:table-driven and demand routing protocol.Considering the mobility,dynamic of topology,bandwidth limitation and power restriction,on-demand routing protocols are more suitable for Ad Hoc network.The thesis firstly describes the signifieance and its'target,it also describes the current status of the schedule.And then through analyzing AODV routing protocols of Ad hoc Network.2hop-AODV is presented which is preformed by AODV routing protocol. Route table in 2hop-AODV is extended by adding two fields to save the previous two hop.And then,according to the discoveried packets,marked down the previous two hop of the router and the reverse router. Once a node finds that the destination is in its two-neighbor area,it replys.By this ahead responsion,the delay of the time in finding route can be reduced clearly.Simulation with different scenes is completely based on NS2,the popular simulated formwork,and performance of 2hop-AODV is superior to the AODV in delay.