Abstract— Power dissipation has constrained the performance boosting of modern computer systems in the past decade. Dynamic power management (DPM) has been implemented in many systems to change the system (or device) state dynamically to reduce the power consumption. This paper explores how to efficiently and effectively reduce the energy consumption to handle event streams with hard real-time or quality of service (QoS) guarantees. We adopt Real-Time Calculus to describe the event arrival by arrival curves in the interval domain. To reduce the implementation overhead, we propose a periodic scheme to determine when to turn on/off the system (or device). This paper first presents two approaches to derive periodic scheme to cope with systems with only one event stream, in which one approach derives an optimal solution for periodic power management with higher complexity and the other derives approximated solutions with lower complexity. Then, extensions are proposed to deal with mult...