Graph-Based Data Gathering Scheme in WSNs With a Mobility-Constrained Mobile Sink

Sink mobility can improve the energy efficiency and data gathering performance in wireless sensor networks. However, mobility of the sink station may be constrained in some applications and it becomes a challenge to optimize the network performance for random distribution and hierarchical topology. We focus on prolonging the network lifetime and keep the data gathering performance at an acceptable level. To address this issue, we propose a comprehensive data gathering scheme based on graphing technique, called double optimization of energy efficiency (DOEE) to optimize the energy consumption of all sensor nodes hierarchically. The objective problem of DOEE is solved with a heuristic algorithm. Along with the scheme, we also specialize a route discovery protocol and its corresponding dynamic gateway protocol to balance the energy consumption among sensor nodes. The proposed algorithm and protocols are evaluated in the simulation platform Network Simulation-3 and the experiment results show our technique has superior performance.