In this work, we analyze the power characteristics of interactive systems, and employ the user interface information, history, and Psychology theories to predict user delays during system-user interaction. We show that such delay predictions can be utilized by DPM/DVS techniques to reduce system energy consumption very effectively. As far as we know, this is the first work that addresses power optimization of interactive systems from the perspective of system-user interaction. Unlike other works, in which energy reduction is reported only for the processor, we report energy reduction for the whole system.
The paper is organized as follows. After discussing background and related work in Section II, we detail the model we employ for system-user interaction in Section III. User-delay models based on Psychological theories and history are proposed in Sections IV and V, respectively. We show how DPM/DVS techniques can take advantage of predicted user delays to save energy in Section VI. We then present our benchmarks and experimental results in Section VII. Next, we present discussions in Section VIII and conclusions in Section IX.