A Low Overhead On-Demand Routing Protocol For Mobile Ad Hoc Network

Ad hoc network is a multi-hop wireless network which is a set of mobile nodes which communicate over radio. These kinds of networks are very flexible, thus they do not depend any existing infrastructure or central administration. Therefore, mobile Ad hoc networks are suitable for temporary communication links. It is widely applied in modern military fields, emergency rescue, disaster recovery, sensor network, wireless local area network and Inter-vehicle communication. Owing to its self organization, rapid deployment and absence of any fixed infrastructure, Ad hoc networks are gaining popularity as a significant and promising research domain. The route between nodes is the key problem in Ad hoc. Dynamically changing topology and lack of network resource make the design of an adaptively distributed routing protocol challenging.This thesis describes several Table-Driven Routing Protocol and On-demand Routing Protocol, and upon the analysis we propose a new routing protocol, named LOOR (Low Overhead On-Demand Routing). A efficient routing broadcasting algorithm, which is used to restrict flooding, is presented during route discovery for LOOR, it can select the forwarded RREQ packets by Euclidean Distance. This paper presents also a local route repair and route optimization algorithm, which is based on node height, can repair the failure path to enhance robustness of the path and reduce the route discovery frequency.We design and realize the LOOR with C++ in Linux operating system, a lot of simulation experiments have been done under NS2, then cpmpare the new protocol with AODV (Ad hoc On Demand Distance Vector) which is a classical On-demand Routing Protocol on normalized routing overhead, routing discovery frequency, packet delivery ratio and average hop count per routing, the results show that LOOR can reduce the average hop count of routing, decrease the route discovery frequency, increase the packet delivery ratio, and decrease the routing overhead obviously, and improve the efficiency of the Ad hoc networks.