Research And Optimization On Routing Protocol In Mobile Ad Hoc Networks

Mobile ad hoc network (MANET) is a multi-hop wireless communication networkformed without any infrastructure support or central administration, and it is a collectionof mobile nodes which use wireless interface to send data. Because the mobile ad hocnetworks can be self-organized and easily deployed, they have been widely applied inmilitary and civil communication fields such as military, disaster recovery, scientificinvestigation, temporary conference etc. Each node in mobile ad hoc networks serves asrouter and host, they are responsible for providing and maintaining a feasible path totransmit data to destination, so an effective routing protocol becomes an essentialproblem in mobile ad hoc network.In mobile ad hoc networks, the stochastic character of each node for its movingspeed and moving pattern makes the topology of network changing at any time.Meanwhile, the channel bandwidth and the energy of nodes are limited, which requiresus to consider the QoS requirements when designing routing protocols. In the view ofthe above background, a new multi-constrained on-demand protocol called ELQRP(Energy Optimization and Load Balancing QoS On-Demand Routing Protocol) isproposed based on AODV in ad hoc network, which combines energy consumption andlink load as the QoS parameters to establish a route. Also on the one hand distanceinformation is used to control the broadcasting direction of RREQ packets, on the otherhand both energy and queue threshold are applied to limit the forwarding of RREQpackets, reducing the unnecessary routing overhead. In the phase of routingmaintenance, the proposed protocol uses the remaining energy information to restrictthe local repairing, which prevents power exhausting nodes from building the routing.Simulation results by NS2show that ELQRP can improve the networks performanceseffectively, especially the delivery rate, normalized routing overhead and end-to-enddelay.