| Coverage problems, including point coverage, area coverage, and barrier coverage, are important issues in wireless sensor networks. Different from point coverage that covers specific points of interest, and from area coverage that covers the entire region, barrier coverage aims at detecting intruders that attempt to cross the network. It requires a chain of sensors across the deployed region with the sensing areas of adjacent sensors overlapping each other. Each independent chain of sensors is acting as a barrier to detect intruders attempting to cross the network. Barrier coverage of wireless sensor networks is of great importance for military and homeland security applications to guard boundaries of battlefields, critical infrastructures, assets such as country borders, and coastal lines.In this dissertation, we seek to characterize, model, and design barrier coverage in wireless sensor networks. Using mathematical analysis and simulations, we first derive critical conditions for the existence and number of independent sensor barriers. We then devise a divide-and-conquer algorithm, that constructs barrier with significantly improved efficiency over existing work in the literature. We further consider a Line-based Normal Random Distribution for sensor deployment, which is more suitable than the widely used Poisson point process for many application scenario. Finally, we study barrier coverage problem with mobile sensors. Sensor mobility offers a great potential to improve barrier coverage, but it also introduces unique challenges. We study the required theoretical boundary of sensor mobility and present a deterministic algorithm to test if an area if barrier coverable with mobile sensors. Then we propose a heuristic algorithm that efficiently relocate mobiles to fill the gap between static sensor when they are deployed in Line-based Normal Random Offset distribution.The results obtained in this dissertation is important to understanding and design of barrier coverage in wireless sensor networks. This work will provide important guidelines to the deployment and performance of wireless sensor networks for barrier coverage. |
