Review of recovery techniques to recapture lost targets in wireless sensor networks

Target tracking, which is one of the most important applications in wireless sensor networks, has received considerable attention in the last few years. The main objective of Object tracking sensor network (OTSN) is to track single or multiple targets and report their latest location to the application's user. However, these targets may get lost due to several reasons such as presence of obstacles or holes in the network, sudden changes in the target's trajectory, localization and prediction errors. This can be a crucial issue in sensitive applications like the military field. To overcome such problem, efficient and strong approaches are needed to retrieve the lost target in a timely manner. This article reviews some recovery strategies proposed in literature, and discusses the main reasons that result in target losses. Then the paper provides a detailed analysis and comparison between these strategies.