Path problems in wireless sensor networks

Abstract

As the wireless sensor network technology advances, many applications for wireless sensor networks interacting with mobile agents continue to emerge. In these applications, paths for mobile agents are often considered important. In this thesis, we consider two problems related with the paths in sensor networks : path-based coverage problem and navigation problem. In the path-based coverage problem, we solve two geometric problems. First, we propose a new coverage measure of the sensor network considering arbitrary paths. Surprisingly, this new measure captures both the best-case and the worst-case coverage of the sensor network, namely, support and breach, simultaneously, enabling us to evaluate the given network in a global viewpoint. We also present algorithms to deploy additional sensors to improve the coverage. Second, we consider the path-based coverage in heterogeneous sensor networks. This is the first attempt to deal with the path-based coverage in heterogeneous sensor networks. In the navigation problem, we consider the problem of navigating a user to visit event nodes in wireless sensor networks without location information. A set of event nodes is not known in advance. As the set of event nodes changes over time, a navigation path needs to be updated on-line. We propose a novel distributed algorithm to construct and update such a dynamic navigation path to visit a set of event nodes.