The traditional fixing method for coverage gap in wireless sensor network (WSN) mainly targets the homogenous networks, in which all nodes have the same detection radius. By this method, the gaps in the network are covered randomly by mobile nodes, leading to low coverage and resource waste. Considering the different detection radii of actual WSN nodes, this paper explores the gap fixing in heterogenous WSNs, and proposes an improved gap fixing method based on fixing priority. Specifically, the gap fixing points were determined and prioritized with the aid of Voronoi polygons, and then fixed by mobile nodes. After that, the nodes with overlapping sensing ranges were removed to reduce the redundancy. Simulation results show that the improved method can effectively enhance the coverage of the entire network.
