Charge Scheduling in Wireless Rechargeable Sensor Networks Using Mobile Charging Vehicles

With the advent of wireless power transfer technology, batteries of sensors can be charged wirelessly by mobile charging vehicles (MCVs), which increases the lifetime of Wireless Rechargeable Sensor Networks (WRSNs). Most of the existing literature do not consider the energy consumption due to the movement of MCVs with their limited battery capacity, which may cause stranded MCVs with incomplete charging schedule. In this paper, we formulate a charge scheduling problem in WRSN with multiple MCVs that consider different spatio-temporal constraints of movement of MCVs and charging of sensors, where our objective is to maximize the number of alive sensor nodes while minimizing the total energy consumed for MCVs' movement over total energy used in the scheduling. We prove that the problem is NP-complete. The performance of our proposed algorithm is analyzed through detailed simulations, which reveals that our scheme excels in charging 95.7% of the total sensors while considerably reducing the consumption of energy due to MCVs' movement.