Survey on Watchdog Systems and Classifier Based Scheme to Detect Selfish Nodes in MANET

Mobile Ad-hoc Networks (MANETs) is self configured and decentralized wireless network without any prior infrastructure. Every node in it acts as a router as well as end-system and hence each node in MANET is allowed to move freely which makes routing difficult. Combine effort of nodes in Mobile Ad hoc Network makes it more powerful. But supporting a MANET is a cost-intensive activity for a mobile node. Finding routes and forwarding packets consumes bandwidth and energy. One such routing misbehavior is that some nodes may be act as selfish by participating in route discovery and maintenance process, but deny forwarding the packet. Such nodes routing misbehavior reduces the packet delivery ratio and wastes system resources such as power and bandwidth. MANETs lack a centralized monitoring and management point, making it a challenging task to detect such misbehaving nodes effectively