Utility Accrual Real-Time Scheduling with Energy Bounds

In this paper, we consider timeliness and energy optimization in battery-powered, dynamic embedded real-time systems, which must remain functional during an operation/mission with a bounded energy budget. We consider application activities that are subject to time/utility function time constraints, statistical assurance requirements on timeliness behavior, and an energy budget, which cannot be exceeded at run-time. To account for the inevitable variability in activity arrivals in dynamic systems, we describe arrival behaviors using the unimodal arbitrary arrival model. For such a model, we present a CPU scheduling algorithm, called the Energy-Bounded Utility Accrual Algorithm (or EBUA). EBUA is a polynomial-time algorithm that satisfies energy bounds, and provides statistical assurances on individual activity timeliness behavior. We analytically establish several timeliness properties of EBUA. Further, our simulation experiments confirm the algorithm’s effectiveness and superiority.