We propose a system-level integrated power management scheme for battery-operated handheld systems such as cell phones and PDAs. Rather than dealing separately with each system component, we consider the interactions between CPU, WNIC (wireless network interface card), LCD, and applications, to reduce energy consumption at the system-level. Depending on the type of applications, the proposed scheme takes the interaction between CPU voltage and frequency and either LCD clock frequency or WNIC power modes, selectively, or both of them. The proposed method selects voltage for CPU in the context of LCD clock speed to reduce the system energy consumption. The application type and the power mode of WNIC are also considered to control the CPU voltage and frequency. Experimental results show that our scheme reduces the system energy consumption by as much as 30% compared to the systems of simply combining DVS (dynamic voltage scaling) and DPM (dynamic power management) or those of using no energy saving policy.
Bibliographical noteFunding Information:
This research was supported by the National Research Laboratory (NRL) program of the Korean Science and Engineering Foundation (No. M10500000059-6J0000-05910) and the ITRC (Information Technology Research Center) support program supervised by the IITA (Institute for Information Technology Advancement, IITA-2008-C1090-0801-0015 and HY-SDR).
All Science Journal Classification (ASJC) codes
- Hardware and Architecture
- Computer Networks and Communications
- Artificial Intelligence