1. Signal Theory and Communications Department, Polytechnic University of Catalonia, Barcelona, Spain
2. Research and Innovation Department, Nearby Computing S.L., Barcelona, Spain
3. Research and Development Department, Iquadrat Informatica S.L., Barcelona, Spain
4. Transport Network Department, Telefónica I+D/Global CTIO Unit, Madrid, Spain
5. CEID Department, University of Patras, Patras, Greece