1. National Research Council - Institute of Electronics, Computer and Telecommunication Engineering (CNR-IEIIT) and WiLab-CNIT, Bologna, Italy
2. University of Rome “Tor Vergata” and WiLab-CNIT, Rome, Italy
3. University of Bologna and WiLab-CNIT, Bologna, Italy
4. Munich Research Center, Huawei Technologies Duesseldorf GmbH, Düsseldorf, Germany