Researches On Coverage-Hole Recovery Algorithm In Wireless Sensor Network

Wireless Sensor Network(WSN) consists of spatially-distributed sensors, They are capable of sensing, data processing and communication. The WSN is widely used in industry and agriculture, city management, emergency rescue and military. In the WSN, if no sensor node is available in the area due to used up energy or any other reasons, the area forms a coverage holes which can’t be detected by any sensors. To solve the problem of coverage holes in the target area, some algorithms were proposed to detect coverage holes and recovery coverage holes. The main research results are concluded as followed:i. A new coverage hole recovery algorithm in wireless sensor network based on properties of the mobile inner point is proposed. This novel algorithm without location information named SOI was proposed for hole recovery using the mobile nodes, which does not require location information, figures out the optimal inner nodes in the edge of coverage holes, and then moves them to the new positions. Through this mechanism, we can reduce the area of coverage holes. And this algorithm can be easily expanded to3D space, if we replace the inner points with intersectant curved surfaces in the3D sphere. Through the experiment, we show that, compared with exiting algorithms, the algorithms had a better performance in the dense deployed wireless sensor network.ii. Based on the triangle nets and the concept of the grids, a new coverage hole detect algorithm was proposed. The algorithm divides the target area to some triangle grids, and then detect whether the triangle grids are covered by the sensors. We proved that the aglorithm could detect any large holes including triangulted-holes accurately.iii. Based on the triangle nets, a new coverage hole recovery algorithm were proposed. It adds some new sensors to the coverage holes in the special places, so the triangle grids can be covered by these sensors. And this algorithm can be easily expands into the3D space, when converting the sphere-cover to the circle-cover. Compared with the existing algorithms, the algorithm had a better performance.