Network delay-aware energy management for mobile systems

Smartphones and tablets have occupied the every facet of our daily life in recent years. According to a recent survey, users spend over 3 hours a day on their mobile devices. In addition, 76% and 75% of smartphone users perform web browsing and social networking at least once a day, respectively. To fully enjoy their benefits, those mobile systems require a long battery life. However, network errors such as packet losses decrease the battery life more quickly. We analyzed the reason for this through measurements using real smartphones and mobile full system simulation. We found that the smartphones maintain high performance level on packet losses without doing useful work. To address this problem, we propose a method for reducing energy consumption by lowering down performance level with a Dynamic Voltage and Frequency Scaling mechanism when long network delay is expected due to packet losses. Experimental results show that the total energy consumption is reduced by 8.4% without performance loss.