GroupBeat: Wireless sensor networks made reliable

In wireless sensor networks (WSN) node failures are typically detected using a heartbeat application, where a neighbor detects a failed node when it misses successive short messages (ldquoheartbeatsrdquo) that should have been sent by the failed node. However, wireless links are usually lossy, hence, to distinguish node failures from intermittent link failures, the threshold on the number of missed heartbeats is usually set to a large number, incurring in a long delay for declaring a node dead. In this paper we present ldquoGroupBeatrdquo an accurate node failure detection system for WSN and propose the ldquoCommunication By Signalingrdquo scheme as an energy-efficient low-overhead implementation of GroupBeat.