Directional sensor networks have a lot of practical applications, and target coverage is one of the most important issues. In this article, we study the target coverage problem in directional sensor network, where directional sensors can rotate freely around their centers and targets are attached with differentiated coverage quality requirements. Our goal is to maximize the lifetime of sensor network, satisfying the coverage quality requirements of all targets. We model it as the maximum cover sets problem and address it by organizing the directions of sensors into a group of non-disjoint cove...
