A New Local Repair Scheme Based on Link Breaks for Ad Hoc Networks

MANET (Mobile Ad hoc Network) is a mobile multi-hop, wireless self-organized distributed network. This paper introduces the concept and characteristics of MANET, gives a general survey of research on local repair for MANET and proposes a new local repair scheme based on link breaks in order to make up the deficiency of the existing local repair schemes. The improved local repair scheme concerns about the status of nodes and regards the change of status as the basis of local repair. Nodes are required to keep the next two-hop node address for each route entry in routing table. During local repair, the repairing node classifies link breaks and adopts different methods for different link breaks depending on the status of its downstream node. Through using improved RREQ (Route Request) packet in local repair, the repairing node not only tries to discover the route to the destination node of data packet, but also attempts to establish the route to its downstream node (i.e. the next hop node or the next two-hop node). We evaluate the new local repair scheme using mathematical analysis and ns-2 simulator. The results demonstrate that the network performance can be significantly improved using the proposed local repair scheme.