Android OS has function with which an application can be launched at the specified time even if the device is in screen-off state at the time. These application behaviors also consume battery without user’s operation. Naturally, it is expected that for users to understand these behaviors is not easy. It is reported that the most important issue of smartphones is battery . Thus, detecting power consuming applications is an important issue. In this paper, we propose a method for identifying applications which largely drain battery in Screen-off state in Android devices. We monitor the wake-up of Android devices and estimate the power consumption of each application based on the monitoring results. Our experimental results demonstrate that our method can identify power draining applications effectively.CodeShoppy
Experimental Results The experimental results are shown in figure 1. “WakeLock” shows the number of acquired WakeLock in 24 hours. “systemserver” depicts the number of WakeLock acquired by the systemserver process. “AlarmManager” means the number of WakeLock by systemserver with tag AlarmManager. “Power consumption” shows decreased remaining battery [%] in 24 hours. “with_all” is the experiment with the standard applications, which are included in AOSP OS, and the above 42 applications installed. “no_app” shows the results with only the standard applications. The others will be mentioned in the next section. The results show that power consumption and the number of WakeLock acquisitions in screen-off state are increased, that is 17 %, by installing applications. The power consumption without installing the 42 applications is small, that is 5 %. From the figure, we can see that power consumption in screen-off state is mainly caused by installed applications. Thus, we can say that observing application behavior is important for decreasing power consumption in screen-off state. In addition, we can expect that the number of WakeLock acquisitions and power consumption have correlation. Especially, we expect that the power consumption has strong correlation with indirect WakeLock acquisition when using AlarmManager because most of the WakeLock acquisitions are invoked by AlarmManager.
In this section, we discuss ways of applying our method. We applied our method by modifying Android OS. However, alarm information can be obtained with unmodified OS, using dumpsys alarm command by a non-root user. Thus, this method can be easily applied to usual devices in general market. Monitoring WakeLock requires OS modification. This method can be applied by installing modified OS for reference devices. We think this method is useful for application venders and application market administrators for evaluating applications.
In this paper, we focus on power consumption of Android devices in screen-off state. We proposed a method for identifying battery draining applications by monitoring WakeLock acquisitions and sets of alarm. Our experiments have demonstrated that our method can effectively detect applications which heavily consume electric power.