Abstract:

Aiming at the coverage hole problem in hybrid wireless sensor networks (WSNs), we propose a coverage hole recovery algorithm based on polar coordinates. Firstly, we determine the boundary points of coverage holes by calculating the intersections of statistic nodes' sensing circle, and connect the boundary points  to construct coverage hole polygons. Secondly, the location of virtual recovering nodes in every polygon is calculated according to the polar coordinate method. Finally, we build the distance data table between virtual recovering nodes and moving nodes to complete the hole recovery work, that is moving the moving nodes in the table to the locations of virtual nodes that match them. Simulation results show that compared with other similar algorithms, the proposed algorithm can determine and recover the coverage holes in WSNs effectively, and meanwhile it needs less moving nodes and has a shorter average moving distance. In addition, it prolongs the network's life cycle while improving the quality of coverage.

Key words: wireless sensor network, coverage hole, polar coordinate, virtual nodes, life cycle