Research On Coverage Technology Based On Voronoi Diagram In Wireless Sensor Networks

Wireless sensor network coverage control technology doesn't only reflect detection ability of the wireless sensor networks to the objective world, but also directly determines the integrity and accuracy of the data of information collection. At present the most of the coverage protocols are based on the ideal environment, which did not consider the affects of the environmental factors to the communication between the sensors and the detection ability of the sensor. So their practicality appears a bit lacking. In this thesis, the worth learning idea is gotten for the wireless sensor networks whose nodes are random deployed in high destiny in wild, on the basis of a lot of research of a large number of coverage protocol literatures, especially the analysis of those protocols which are based on the Voronoi diagram, and the analysis of fuzzy coverage theory. The mainly research of this thesis is in the following areas:(1) Based on the advantage of the circle plant model what is the clear boundary, and combined the advantage of the probability model what is the good practicality, a fuzzy ring is set which solved the affects of the environmental factors for the detection range of the node, which solved the problem of the practicality of coverage protocols from the bottom. In this thesis, this detection model with the fuzzy ring is called fuzzy detection model which describes the detection model of the node much better. The detection strength of the node within the inside boundary of the fuzzy ring is 1. Between the two boundaries, the detection strength is greater than 0 and less than 1, and out of the outside boundary the detection strength is 0.(2) Based on the So&Ye algorithm and the Voronoi tessellation- based rapid coverage decision algorithm, using the fuzzy detection model and the theory of collaboration coverage, a fuzzy coverage decision algorithm based on the Voronoi diagram (VFCDA) is proposed. VFCDA does not only maintain the advantage of the low time complexity, but also reduce the computation complexity. Especially VFCDA reduces the utilization of the nodes when generated the Voronoi diagram.(3) Based on the RSE algorithm combined the fuzzy coverage model and VFCDA, a redundancy decision algorithm based on the Voronoi diagram is proposed in this thesis, which improves the accuracy of redundancy of the nodes effectively.(4) In this thesis, a fuzzy coverage protocol based on the Voronoi diagram (VFCP) is proposed for the problems of high time complexity and more holes under the affects of the environmental factors of the protocols in the references, on the basis of the distributed coverage protocol based on the Voronoi diagram. And VFCP used the fuzzy detection model, VFCDA, VRDA and fuzzy coverage model. Firstly, the states of the nodes in VFCP are initialized to listening in order to save energy. Then every node generates a random number which is used to compare with the threshold which is set by people. The nodes' states are changed to the state of active selectively according to the result of the comparison. All the nodes with the state of active are connected to a network. The connected network is maintained by the maintenance algorithm according to the states of the nodes.Finally, the NS2 simulation platform is constructed under the Window operation system, and using the simulations proved the effectively and superiority of VFCP.