The Placement Scheme for Static Nodes in a Circular WSN Area Based on the Analysis of Density and Energy

In a wireless sensor network (WSN), the sensors closest to the sink tend to deplete their energies faster than the other sensors, which is known as an energy hole around the sink. To avoid this, a new scheme for placing nodes, via adjusting surface densities and initial energies in each ring in a ring model, is proposed in this paper. A new definition of network efficiency, including the consideration of energy cost, is also introduced and applied. The simulation results demonstrate that this scheme can significantly increase the network efficiency compared with the uniform placement algorithm, especially when the size of the network is relatively large