A selective DVS technique based on battery residual

Abstract

Conventional research on DVS assumes that the battery, which is the power source of most mobile devices, provides constant power; the battery, however, has unique discharge characteristics due to its chemical properties. Based on the residual characteristics of the battery, this paper presents a practical approach towards a battery-aware DVS mechanism that can easily be applied to conventional operating systems. The proposed policy monitors the battery residual in runtime, classifies the current battery state as one of three-the recovery effect region, the rate capacity region and the alarm region-then applies a suitable DVS algorithm according to each region. which takes advantage of the underlying battery characteristics. Experiments on commercial PDAs (iPAQ5550 and Zaurus SL-860 PDA) running MPEG applications showed that our policy significantly extends the battery lifetime, compared to the conventional DVS method, with only a marginal QoS degradation. (c) 2005 Elsevier B.V. All rights reserved.