A least-movement topology repair algorithm for partitioned wireless sensor-actor networks

In Wireless Sensor-Actor Networks (WSANs), sensors probe their surroundings and send their data to more capable actor nodes. The actors' response requires them to coordinate their operation. Therefore, a strongly connected inter-actor topology is necessary and tolerance of an actor failure becomes a design requirement. Autonomous repositioning of actors has been deemed as an effective recovery strategy. In this paper, we present a distributed network recovery scheme called Least-Movement Topology Repair (LeMoToR). To restore connectivity, LeMoToR relies on the local view of a node about the network and strives to relocate the least number of nodes. It also reduces the total travelled distance and overall inter-node communication complexity. LeMoToR do not imposes pre-failure communication overhead and utilises existing path discovery activities in the network to know the structure of the topology. The performance of LeMoToR is validated analytically and through simulation. The validation results demonstrate the effectiveness of LeMoToR.