Research on Energy Hole Problem for Wireless Sensor Networks Based on Alternation between Dormancy and Work

This paper theoretically proposes a more accurate analytical method for avoiding energy hole in wireless sensor networks with nonuniform node distribution. Based on the typical energy consumption model of wireless sensor networks, we obtain the relationship of the densities of sensor nodes in different regions of network through rigorous mathematical analysis, and prove that if the densities of sensor nodes working at the same time are, the entire work can achieve uniform energy consumption by making the sensor nodes whose density is greater than alternate between dormancy and work. Through theoretical analysis and numerical simulation, we obtain the following conclusions: 1) Under the circumstance that the parameters of network do not change, the network lifetime can increase several times by selecting appropriate transmission radius of sensor node. 2) To achieve uniform energy consumption of network, the densities of sensor nodes whose distances from the base station are different should be different. Even if the sensor nodes were in the same circular ring, the densities of sensor nodes in different places should not the same. 3) Through nonuniform node distribution and alternation between dormancy and work, the efficiency of network can increase several times and the residual energy of network is nearly zero when the network lifetime ends. Therefore, our research can give a significant guidance on the optimization of wireless sensor networks.