O-Sleep : Smartphones' Output-Oriented Power Saving Mode

Fast battery discharge is the most concerned issue for smartphone users. This is the result of the smartphone's convergence trend and increasing complexity of its applications. Energy management techniques to reduce unnecessary battery usage are being studied. In this paper, we propose a new paradigm-shifting power saving mode for smartphones. O-Sleep is a smartphone's output-oriented power saving mode. Rather than entering processor sleep mode when there is no user input, o-sleep puts a smartphone's user interface into sleep mode when there is no meaningful output from the phone. While a device is processing a user's request, output from the device may require processing time. We consider the situation as the device's output idle time and put the phone's user interfaces into sleep mode while maintaining other subsystems in active state. To prove our concept, we have applied our technique onto various smartphone applications with varying operation environment. From the experiment, we have found we can save 37% of power consumption during up to 58% of its active usage with our test scenarios.