Reliability guaranteed efficient data gathering in wireless sensor networks

Wireless sensor networks (WSNs) are widely applied in various industrial applications. In this paper, we present an efficient data gathering scheme that guarantees the Quality of Service and optimizes the following network performance metrics as well as the end-to-end reliability in WSNs: (1) minimum total energy consumption; (2) minimum unit data transmitting energy consumption; and (3) maximum utilization efficiency defined as network lifetime per unit deployment. We first transform the performance optimization problem into a problem to optimize the following parameters: (1) deployed nodal number N*; (2) nodal placement d*; and (3) nodal transmission structure p*. Then, we prove that the optimization problem is solvable mathematically. For our observation, the sensor nodes close to the sink trend failed early since they consumed more energy with heavier relay traffic destined for the sink, which seriously affects the network performance. The key point of this optimization is adopting lower reliability requirements and shorter transmission distance for nodes near the sink. Consequently, this reduces the energy consumption of the nodes in the hotspot area. Meanwhile, it adopts higher reliability requirements and farther transmission distance for nodes far from the sink to make full use of the node residual energy, so as to optimize the network performance without harming network reliability. Numerical simulation results demonstrate that our optimal approach improves the network lifetime by 18%-48% and network utility by 17%, and guarantees desire reliability level.