1. Aristotle University of Thessaloniki,Wireless Communications and Information Processing Group (WCIP),Department of Electrical and Computer Engineering,Thessaloniki,Greece,54124
2. Institute for Digital Communications (IDC), Friedrich-Alexander Universitat Erlangen-Nurnberg (FAU),Germany
3. University of Macedonia,Department of Applied Informatics,Thessaloniki,Greece,54636
4. Aalto University,Department of Communications and Networking,Espoo,Finland,02150