Dynamic Coverage Problems in Sensor Networks

One of the fundamental issues in sensor networks is related to analyzing the coverage, or how well a network of sensors monitors the physical space for an intrusion. The coverage is a measure of the quality of service (QoS) of the sensor network and has been the subject of various studies. The concept of coverage was introduced by Gage in 1992, who studied it in relation to multi-robot systems. He defined three classes of coverage problems: blanket coverage (also known as area coverage), where the goal is to achieve a static arrangement of sensing elements that maximizes the detection rate of targets appearing in the region, sweep coverage, where the goal is to move a number of sensors across the region as to maximize the probability of detecting a target, and barrier coverage, where the objective is to protect the region from unauthorized penetration. While blanket coverage is relatively well researched, the other two types of coverage have been less studied and offer much greater technical challenges. In this survey we concentrate on the two dynamic types of coverage problems, barrier and sweep coverage. We review recent results, proof techniques, analyses, and open problems and challenges. We focus on methods that allow the performance of the algorithms, i.e.