1. Feasibility study for Proximity Services (ProSe),2013
2. Study on system enhancement for Proximity based Services (ProSe) in the 5G System (5GS),2022
3. Study on Proximity-based Services in 5GS Phase 2;3rd Generation Partnership Project (3GPP), Work Item Description SP-211653,2021
4. Introducing additional mission-critical use cases for 5G Sidelink, technology gaps and proposed enhancements,2022
5. Study of 5G New Radio (NR) Support for Direct Mode Communications