Research Of Nodes Deployment Based On Virtual Grid In Wireless Sensor Networks

As a newly emerging thing under the background of Internet blossoming, Wireless Sensor Networks (WSNs) have played an important role in aspects of industry, military, and environment. In practical application, Most of the sensor nodes deploy in the sensing field randomly by tossing. The deployment scheme of sensor nodes has a direct effect on the coverage and the cost of WSNs. As a consequence, this paper addresses the issue of Wireless Sensor Network deployment and we have carried out some interrelated analysis and research to solve the deployment of sensor nodes in sensing field.To solve the issue of homogeneous nodes deployment in two-dimensional space, a sensor deployment algorithm with variable step size based on hexagonal grid was proposed. The sensing field was drawn into lots of hexagonal grids. Using the location information of each hexagon's center and the randomly deployed sensor nodes, each node's targeting grid could be found. The node should be deployed at the targeting grid's center. Based on the distance between the deploying nodes and the targeting grid's center, the move step could be selected. When the distance was greater than the maximum step size, the maximum step size was selected as the node's move step. When the distance was less than the maximum step size, the current distance was selected as the node's move step. When the node was in the center of the targeting grid, the move step was zero. At the same time, taking the effect of the hexagonal grids'location into account provided a founded theoretical basis to validate the robustness of the proposed algorithm. Simulation results showed that the proposed algorithm could achieve more than 95% coverage with a faster convergence speed and a lower average moving distance with a reduction of 19%.To solve the issue of heterogeneous nodes deployment in two-dimensional space, a static deployment algorithm based on equilateral triangle partition was proposed. We modeled the coverage of sensor nodes which was heterogeneous in perceived radius and got the best ratio of perceived radius with which the coverage function could achieve the maximum. Using the location information of each equilateral triangle's center and vertex, the nodes with bigger perceived radius were deployed in the vertex of equilateral triangle grids and the nodes with smaller perceived radius were deployed in the center of it. The nodes with different sensing range could be fully used and the coverage of the sensing field could be achieved.