A Real-Time Feedback Scheduler for Environmental Energy with Discrete Voltage/Frequency Modes

This paper, addresses the problem of real-time scheduling in ambient energy harvesting systems with discrete voltage/frequency modes through the use of a feedback scheduler. The main idea explored in this paper is to reduce the processor speed in proportion to the amount of available energy and processor load. The evaluation of this new real-time feedback scheduler shows experimentally a good compromise between the available energy and the processor workload, and allows a progressive selection of processor speeds. In this work, we compare several battery thresholds knowing that the processor performs the tasks at maximum speed when the battery storage is over the thresholds.