The Carat research team has published a dataset focusing on collaborative energy diagnostics of mobile devices and applications



The Carat research team from University of Helsinki publishes a dataset from the Carat project ( focusing on collaborative energy diagnostics of mobile devices and applications. The dataset was presented at the IEEE PerCom’15 conference last spring in the publication "Energy Modeling of System Settings: A Crowdsourced Approach" that won the Marc Weiser Best Paper Award given at the conference.

The dataset contains different smartphone context factors, such as system settings and subsystem variables, and energy rates from 149,788 mobile devices of 2535 different Android models during 2013 and beginning of 2014. In total, there are 11,209,125 data items. They contain, for example, information about Wi-Fi and mobile network usage and quality, screen brightness levels, battery temperature and voltage measurements, and CPU usage. The data can be freely used for research and educational purposes.


In our work, we show how combinations of different system settings and subsystem variables can be used to model and predict energy usage of mobile devices. Some system settings have a direct and significant correlation with energy consumption, for example screen brightness and network connectivity. The energy impact of other system settings and their combinations can be much more difficult to predict, such as the combination of roaming, high operating temperature, and bad signal strength. Our work demonstrates that the energy impact of these non-trivial system setting combinations can be significant, and presents a new learning based method for assessing this impact.

Read more about the dataset and our research:

Ella Peltonen, Eemil Lagerspetz, Petteri Nurmi, and Sasu Tarkoma. Constella: Recommending System Settings the Crowdsourced Way. Pervasive and Mobile Computing. To appear 2016.



Ella Peltonen, Eemil Lagerspetz, Petteri Nurmi, and Sasu Tarkoma. Energy Modeling of System Settings: A Crowdsourced Approach. In Proceedings of the IEEE International Conference on Pervasive Computing and Communications, PerCom '15, St. Louis, MO, USA, March 23-27, 2015.



The Carat context factor dataset can be downloaded from our website



Created date

26.11.2015 - 09:57

New web pages!


The new Computer Science web pages are located on the server.

The address redirects now to the new pages. This short address can still be used as the web address of the Department. The old site can be found at


Inaugural lectures on Wed 29.11. in the Main Building

New professors of Computer Science will have their inaugural lectures (20 minutes each) on Wednesday 29.11. in the Main Building, Room 6 new side, 3rd. floor.

Before the lecture the Dean Esko Ukkonen will briefly introduce Pan Hui.


Before the lecture the Vice dean Minna Nyström will briefly introduce Ville Mustonen.

15.15 Ville Mustonen: Voiko evoluutiota ennustaa?

Uni­versity of Hel­sinki elec­ted Nokia Bell Labs part­ner

The collaboration between Nokia and the university is tightening in the field of data science; the research into data networks, artificial intelligence, and enhanced reality is receiving more attention.

The Department of Computer Science celebrates its 50th Anniversary


This year the Department of Computer Science of the University of Helsinki celebrates its 50th Anniversary. The festivities include a Jubilee Seminar on Thursday 31 August 2017, at 1-6 p.m., in the Great Hall of the University Main Building (Unioninkatu 34).