An energy-aware framework for coordinated dynamic software management in mobile computers

Energy efficiency is a very important and challenging issue for resource-constrained mobile computers. We propose a dynamic software management (DSM) framework to improve battery utilization, and avoid competition for limited energy resources from multiple applications. We have designed and implemented a DSM module in user space, independent of the operating system (OS), which explores quality-of-service (QoS) adaptation to reduce system energy and employs a priority-based preemption policy for multiple applications. It also employs energy macromodels for mobile applications to aid in this endeavor. By monitoring the energy supply and predicting energy demand at each QoS level, the DSM module is able to select the best possible trade-off between energy conservation and application QoS. To the best of our knowledge, this is the first energy-aware coordinated framework utilizing adaptation of mobile applications. It honors the priority desired by the user and is portable to POSIX-compliant OSs. Our experimental results for some mobile applications (video player, speech recognizer, voice-over-IP) show that this approach can meet user-specified task-oriented goals and improve battery utilization significantly. They also show that prediction of application energy demand based on energy macro-models is a key component of this framework.