Barrier Coverage Of Wireless Sensor Networks

Coverage control, as one of the most fundamental problems in wireless sensor networks(WSN), is an important evaluating indicator for measuring the performance of the sensor networks. It optimizes not only the spatial resources of WSN, but also affects network energy consumption, survival time, quality of service as well as other important parameters. Moreover, reducing power consumption, improving validity of network, and prolonging the network lifetime are the primary goals of wireless sensor networks. Designing appropriate topology control algorithm is one of the important technologies to achieve this goal. Consequently, barrier coverage, as an important part of coverage problem, aims to observe the probability of inducted target being detected by nodes in a particular monitor area of WSN. The research of barrier coverage has a great significance and widespread application.Barrier coverage includes best coverage, worst coverage and exposure. On the basis of Delaunay triangulation of computational geometry and graph theory, the research mainly focuses on the best coverage and the thesis involves three areas which are centralized topology control, distributed topology control and the distributed best-coverage-path.An improved Voronoi algorithm based on auto connected Delaunay is proposed on a centralized topology structure. Compared to the original algorithm, the efficiency of improved algorithm is obviously improved in the process of building Delaunay triangulation and Voronoi diagram. On the basis of improved algorithm, the simulation results show that the best-coverage-path and the worst-coverage-path can be obtained on a centralized topological graph. A Mutual Edge Distributed Delaunay Triangulation algorithm (MEDDEL) is proposed on a distributed topology structure of wireless sensor networks, which can be run only by each node distributively with 1-hop neighborhood information. It builds MEDDEL more efficient. The bidirectional connectivity, planar structure, sparseness and the property of t-spanner are proved. Besides unit Delaunay triangulation(UDEL) is a subgraph of MEDDEL. By applying it to mobile wireless sensor networks, topology control of MEDDEL maintains the characteristics of Delaunay Triangulation. The support weight of MEDDEL is calculated and proved.The best-coverage-path of wireless sensor networks can be confirmed to MEDDEL efficiently and the best coverage problem is solved by a distributed Shortest travelling distance and Minimum energy consumption of Best-Coverage-Path algorithm (SMBCP). Compared to relative neighborhood graph (RNG), Gabriel graph(GG), planar localized Delaunay triangulation(PLDEL), UDEL, Delaunay triangulation(DEL), the simulation results show that the best-coverage-path with shortest travelling distance and minimum energy consumption can be found by SMBCP algorithm. And then, taking into account of the dynamic situation in which nodes dynamically join and leave the network in barrier coverage, the algorithm solves the problem that the best-coverage-path with shortest travelling distance and minimum energy consumption can be changed by dynamically joining nodes and leaving nodes of the best-coverage-path. Finally, the simulation results confirm that the algorithm is correct and valid.