Target-Temporal Effective-Sensing Coverage in Mission-Driven Camera Sensor Networks

This paper introduces two new coverage problems in mission-driven camera sensor networks, namely the target temporal effective-sensing coverage with non-adjustable cameras (TEC-NC) problem and the target-temporal effective-sensing coverage with adjustable cameras (TEC-AC) problem. Given a mission period, the objective of the problems is to find a sleep-wakeup schedule of the camera sensor nodes such that the overall target-temporal coverage is maximized. We formally introduce a method called Identifiability Test to check if a target with a face direction is effectively-covered by a camera sensor, and prove the problems are NP-hard. For TEC-NC, we propose a 2-approximation algorithm and two heuristic algorithms. We also design a greedy strategy which can be combined with our solutions for TEC-NC to solve TEC-AC. The simulation results indicate the quality of the outputs of our algorithms are much better than that of the existing alternative as well as close to the theoretical optimum on average.