Enhanced Channel Estimation and Traffic Monitoring for Misbehaviour Nodes in Disruption Tolerant Networks

In disruption tolerant networks (DTNs), the malicious nodes can be detected by watchdog and pathrater solutions. To address the problem of noise between the nodes, a distributed scheme has been used to detect the packet dropping in DTNs, where a node is used to keep a few signed contact records of its previous contacts, based on it the next contacted node is detected whether the node has dropped any packet. Since misbehaving nodes may misreport the contact records in order to avoid being detected, a small part of each of the contact record is disseminated to a certain number of witness nodes. A scheme to mitigate routing misbehaviour by limiting the number of packets forwarded to the misbehaving nodes is used. Thus the misbehaving nodes ensure low packet delivery, throughput, end to end latency and more energy consumption. So a Channel Aware Detection (CAD) algorithm is used to enhance the above metrics and to limit the traffic flowing to the misbehaving nodes. The CAD algorithm is used based on two strategies, the channel based estimation and traffic monitoring. If the monitored loss rate at particular hops exceeds the estimated normal loss rate, those nodes identified will be taken as attackers. The NS2 simulation shows that the solutions are efficient and effectively enhance routing misbehaviour.