A Novel Sink Mobility Off-line Algorithm for Avoiding Energy Hole in Wireless Sensor Network

In multi-hop data collection sensor network, nodes near the sink need to relay remote data, thus, have much faster energy dissipation rate and suffer from premature death. This phenomenon cause energy hole near the sink, seriously damaging the network performance. In this paper, we propose sink mobility with adjustable communication range to avoid the energy hole. First of all, we compute energy consumption of each node when sink is set at any point in the network through theoretical analysis. Based on detailed analysis of factors that affect the network life, the paper proposes an off-line centralized algorithm to compute the theoretically optimal track of the movements of sink, the number of halt positions, as well as the available maximum network lifetime. Theoretical analysis and experimental results show that the proposed algorithms improve significantly the lifetime. It lowers the network residual energy by more than 30% when it is dead. Moreover, the cost for moving the sink is relatively smaller.