Partial Charging Scheduling in Wireless Rechargeable Sensor Networks

Abstract

Partial charging in wireless rechargeable sensor networks (WRSNs) has been proposed recently, offering an new alternative in dealing with non-schedulable charging tasks. Most previous charging scheduling algorithms assume that a mobile charger must replenish a sensor to its full energy capacity in fulfilling every charging task (non-preemptive tasks). However, this charging manner degrades the charging efficiency and shortens the network lifetime to some extent. On the other hand, a partial-charging model is more effective and flexible. Although some previous works adopted a partial-charging model, they failed to theoretically formalize the schedulability of partial charging scheduling for WRSNs. To the best of our knowledge, this work first proposes a schedulability evaluation mechanism for such partial-charging scheduling. A partial charging scheme (PCS) based on schedulability evaluation for the on-demand charging architecture is given. Next, a simple case is presented for better comprehension and to demonstrate the merits of PCS. Additionally, test-bed experiments are conducted to compare the performance between the proposed scheme and previous schemes by applying different wireless energy transfer standards.