Arbitrary Obstacles Constrained Full Coverage in Wireless Sensor Networks

Coverage is critical for wireless sensor networks to monitor a region of interest and to provide a good quality of service. In most cases we need to achieve full coverage which means every point inside the region (excluding the obstacles) must be covered by at least one sensor. The problem of placing the minimum number of sensors to achieve full coverage for a region with obstacles is NP-hard. Most existing coverage methods, such as contour-based ones, simply place sensors along the boundaries to cover the holes near obstacles and the region boundary. These methods are inefficient especially when obstacles or the region become irregular. In this paper, based on computational geometry, we design a deterministic full coverage method, which accurately finds the uncovered holes and places sensors efficiently for both the regular and irregular obstacles and regions. Specifically, we show that the more irregular of the obstacles and the region, the more sensors our method saves.