The energy consumption is one of the greatest challenges for current mobile devices.
Energy and power continue to remain the most limiting factors for the
performance of mobile computing systems. The battery capacity increases
approximately 10% annually while the requirements increase in a more rapid pace.
In several consumer surveys the duration of the battery charge has been
named as one of the top five problems. The near future does not look any
better; the increasing complexity of computing platforms and new services
increase the energy consumption requirements. Recent developments pertaining
to energy source have not kept pace with the increasing requirements.
Especially Internet and Web 2.0 service usage consume vast amounts of
energy and result in short battery lifetimes, and ultimately poor
user experiences. 

With these topics you study energy modeling and prediction for
smart phones and develop models for estimating energy consumption.