1. Part 30: Upper Microwave Flexible Use Service;30 202 Power Limits FCC,2020
2. Envisioning Device-to-Device Communications in 6G
3. UMTS-LTE Proximity-Based Services (ProSe);3GPP TS 23 303 Release 12,2014
4. Proximity based Services (ProSe) in the 5G System (5GS);3GPP TS 23 303 Release 17,2021
5. Communications in the 6G Era