1. Department of Computer Science, Aalto University, Espoo, Finland
2. Department of Computer Science, University of Helsinki in Helsinki, Helsinki, Finland
3. Technology Innovation Institute, Masdar City, Abu Dhabi, United Arab Emirates
4. Institute of Theoretical and Applied Informatics, Polish Academy of Sciences in Gliwice, Gliwice, Poland
5. Centre of Wireless Communications, University of Oulu, Oulu, Finland