Link Scheduling in Rechargeable Wireless Sensor Networks with Battery Memory Effects

Abstract

This paper considers deriving a link schedule for rechargeable WSNs. Unlike past works, it considers: (i) the time required by nodes to harvest energy, and (ii) deterioration in battery lifetime due to memory effects. It presents a greedy heuristic that schedules links according to the earliest time in which the batteries at each link’s end nodes are fully discharged. Our results show that considering memory effects via a battery cycle constraint and energy harvesting time increases the link schedule by up to 30.43% and reduces the number of charge/discharge cycles of battery by up to 84.05%. Hence, it helps to increase a battery’s lifetime. On the other hand, an increase in energy harvesting time linearly increases link schedules but it does not affect the number of charge/discharge cycles. Finally, increasing a battery’s depth of discharge reduces its number of charge/discharge cycles by up to 399.84%, while lengthening the link schedule by up to 7.03% only.