Schedulability decision of charging missions in wireless rechargeable sensor networks

TLDR: This paper proposes an optimistic and a pessimistic condition that can efficiently determine the schedulability of a charging mission, derived from a generalized formulation of charging schedules.

Abstract: Wireless Rechargeable Sensor Networks (WRSNs) have received wide attention in recent years due to their potential to solve the energy problem. With a Mobile Charger (MC), the newly developed charging schemes can be readily applied on a WRSN running traditional protocols. An essential issue in deploying a WRSN is to decide the schedulability of its charging mission. Because one must determine whether the MC can guarantee that no sensor node will stop working within a target lifetime, before designing any specific charging schemes. To tackle the decision problem, this paper proposes an optimistic and a pessimistic condition that can efficiently determine the schedulability of a charging mission. Both of the decision conditions are derived from a generalized formulation of charging schedules. If the MC meets the optimistic condition of a charging mission, a simple and efficient charging scheme can be immediately applied to keep continuous working of the WRSN. While if the pessimistic condition of a charging mission is not met, no valid charging schedule exists. Three methods can be considered when schedulability of a charging mission is still undetermined.