1. 3GPP, TR 22.803 v12.2.0-Feasibility study for Proximity Services (ProSe), Jan.2013.
2. 3GPP, TR 36.843 v12.0.1-Study on LTE Device to Device Proximity Services, Mar.2014.
3. 3GPP, TS 23.303 v14.1.0-Proximity-based services (ProSe); stage 2, Dec.2016.
4. 3GPP, TS 22.278 V15.1.0- Service requirements for the Evolved Packet System (EPS), Mar.2017.
5. A John Wiley and Sons, Ltd., LTE – The UMTS Long Term Evolution, ISBN.9780470697160, 2009.