Network Utility Optimization in RF Energy Harvesting Wireless Sensor Networks via Fixed-trajectory Mobile Charging

This paper considers the network utility maximization (NUM) problem in radio frequency (RF) energy harvesting sensor networks with static routing and mobile charging periodically, using one mobile charger (MC) to move along the constrained and fixed trajectory for cost-efficient energy provision. For the first time, the sampling rates of sensor nodes and time allocation of mobile charger are jointly optimized under energy consumption and patrolling cycle constraints, aiming to maximize the network utility. We discretize the trajectory into segments and decouple this original convex problem into two separable sub-problems and obtain the approximately optimal solution. Simulation results demonstrate that our proposed algorithm always outperforms the baseline schemes with uniform sampling rate of sensors or constant moving speed of MC.