Research And Implementation Of AOMDV-ES Energy-saving Routing Protocol Based On Stability Of Main And Alternate Links

A mobile ad hoc network (MANET) is a special type of multi-hop and temporary wireless networks, which is independent of any fixed infrastructures. Due to the characteristics such as dynamic changes of network topology, self-organization, limited energy and bandwidth, etc., MANET performs flexibility and practicality, while there are also many issues in it. In this case, researchers pay more and more attention to the MANET investigation, in which the energy-saving and stable routing protocols are becoming one of the research hot spots and difficulties in network research area.AOMDV is a typical on-demand multipath distance vector routing protocols which has become a research focus in MANET. It establishs multiple paths which are loop-free and link-disjoint, and is thereby allocating the traffic, providing high total bandwith, improving effective resilience to network failures and allow for network load balancing through the simple mechanism. In MANET, as resource is limited, the flooding of control message at route request procedure can lead congestion to network. Meanwhile, the paths which are selected with shortest delay are not quite stable for not taking the energy of node and the congestion degree into account. Finally, if the cost of the dynamic maintenance of multipath is very large, it will offset the advantages of multipath.To address the issues mentioned above, the thesis presents an AOMDV-ES energy-saving routing protocol based on stability of main and alternate links. AOMDV-ES makes improvements mainly from the following aspects:first, this thesis combines the idea of expending ring search at route discovery process, and forwards messages according to the status parameters recorded which reduces some unnecessary rebroadcasting of multiple RREQ messages. This heuristic algorithm achieves a substantial amount of energy-saving by optimizing the initial TTL, the incremental value of searching ring and other parameters through the historical hops information recorded. It results in flooding in smaller areas before a successful search in the final round of the flooding, and a decrease of the redundancy broadcasting and collisions after the routes to the destination are discovered. Second, AOMDV-ES chooses the most stable links on the basis of routing cost function; as a consequence, the protocol achieves better performance in packet delivery ratio, average end-to-end delay and the times of link repair. Third, AOMDV-ES only maintenances the dynamical paths along which to deliver data and thus reduces the flooding of control messages.This thesis gives a detailed description about AOMDV-ES routing protocol and evaluates the AOMDV-ES and AOMDV multi-path routing protocols based on the NS2network simulation software. The thesis presents the anylasis and comparison of simulation results. The study shows that the AOMDV-ES routing protocol improves packet delivery ratio and decreases the average end-to-end delay and the routing cost vers AOMDV, which indicates the effectiveness of AOMDV-ES protocol.