Research Of Ad Hoc Routing Based On On-demand Multipath

A mobile Ad Hoc network is an autonomous system of mobile hosts connected by wireless links. This network can be built rapidly and easy, and it is not set measures to by wired network and so on,so it will be used widely in the future.This dissertation first presents two routing protocos including proactive protocols and on-demand protocols .Using NS-2, this paper simulate with the three typical on-demand routing protocols namely AODV,DSR and TORA.Under different of traffic and mobility scenarios,we give the simulation result of the thre typical on-demand routing protocols. The simulation results show that on-demand protocols of AODV and DSR indeed more predominant than others on capability. And then introduces Ad Hoc network multipath routing protocols,especially explains the advantages between single-path routing protocol and multi-path routing protocos.We develop and evaluate two technique schemes based on-demand multipath protocols.The first. technique analyzes the stability of the multipath and gets that the stability of multipath routing is closely related to the routing strategies, So it improves the multipath routing scheme which is based on DSR and utilizes a group of independent paths to route. This paper compares the algorithm with some protocols(SMR, DSR), the simulation result shows that the algorithm is more efective than SMR, DSR. The second technique is to reduce the number of route discoveries due to such broken paths, multipath routing can be utilized so that alternate paths are available. Current approaches to multipath routing make use of pre-computed routes determined during route discovery. These solutions, however, suffer during high mobility because the alternate paths are not actively maintained. Hence, precisely when needed, the routes are often broken. To overcome this problem, we present an adaptive multipath solution. In this approach,multiple paths are formed during the route discovery process. All the paths are maintained by means of periodic update packets unicast along each path. These update packets measure the signal strength of each hop along the alternate paths. At any point of time, only the path with the strongest signal strength is used for data transmission.In this scheme, we present two variations of our protocol and evaluate both with respect to two previously published multipath routing protocols. Simulation results show that the proposed solutions result in significant performance improvement.Investigation show that the IMR and MP-AOMDV on-demand multipath protocols work well than DSR and AODV in mobile Ad Hoc networks, especially in frequently moving scenarios.