Energy assignment to prolong the lifetime in heterogeneous wireless sensor network

This paper focuses on prolonging the sensor network lifetime by assigning the sensor nodes with initial energy properly in the heterogeneous wireless sensor network. The initial energy assignment (IEA) strategy is proposed either the total initial energy is limited or unlimited. The location and energy level of sensors are given to optimize the load balance and prolong the network lifetime. When the total available energy of all the nodes is limited, the network life is 92% longer using the IEA strategy than using the uniform initial energy assignment strategy; when the total energy of all nodes is unlimited, the network lifetime on the IEA strategy will increase about 12 times longer than on the uniform energy allocation. The numerical approximation for the IEA strategy is presented in this paper, and the nodes density and the radius of deployment are also discussed to maximize the network lifetime.