Coverage-aware connectivity restoration in mobile sensor networks

Mobile sensor networks rely heavily on inter-sensor connectivity for collection of data. Nodes in these networks monitor different regions of an area of interest and collectively present a global overview of some monitored activities or phenomena. A failure of a sensor leads to loss of connectivity and may cause partitioning of the network into disjoint segments. A number of approaches have been recently proposed that pursue node relocation in order to restore connectivity. However, these approaches tend to ignore the possible loss of coverage in some areas, either due to the failure itself or due to the connectivity-limited focus of the recovery. This paper fills this gap by addressing the connectivity and coverage concerns in an integrated manner. A novel coverage conscious connectivity restoration (C3R) algorithm is presented. C3R involves one or multiple neighbors of the failed node to recover from the failure. Each neighbor temporarily relocates to substitute the failed node, one at a time, and then returns back to its original location. This leads to intermittent connectivity and monitoring of all the originally covered spots. This paper also presents energy-centric optimized recovery algorithm (ECR), an optimized version of C3R that is geared for energy efficiency. Both C3R and ECR are validated through simulation. The simulation results confirm the effectiveness of these approaches.