Fault Detection in MANETs

Node faults may be frequent in a mobile ad hoc network (MANET). Most work related to fault detection and localization for MANETS essentially use changes in topology to identify faults. Most of this work does not distinguish between node movement that results in a functioning node moving out of range of all other nodes versus a node that crashes as the result of a radio transmitter malfunctioning or a battery no longer operating. This paper introduces a novel protocol that makes this distinction. Nodes forward their neighbourhood observations to a cluster head. The cluster head uses this to determine a list of suspected crashed nodes and sends this list to all the other nodes to filter out those nodes that have moved out of range. The cross-layer implementation of the protocol is effective in distinguishing between crashed nodes and nodes that have moved out of range.