1. 3GPP. TS 23.228 IP Multimedia Subsystem (IMS). http://www.3gpp.org/DynaReport/23228.htm. 3GPP. TS 23.228 IP Multimedia Subsystem (IMS). http://www.3gpp.org/DynaReport/23228.htm.
2. 3GPP. TS 23.401 GPRS Enhancements for Evolved Universal Terrestrial Radio Access Network (E-UTRAN) Access. http://www.3gpp.org/ftp/Specs/html-info/23401.htm. 3GPP. TS 23.401 GPRS Enhancements for Evolved Universal Terrestrial Radio Access Network (E-UTRAN) Access. http://www.3gpp.org/ftp/Specs/html-info/23401.htm.
3. 3GPP. TS 23.501 System Architecture for the 5G System. http://www.3gpp.org/ftp/Specs/html-info/23501.htm. 3GPP. TS 23.501 System Architecture for the 5G System. http://www.3gpp.org/ftp/Specs/html-info/23501.htm.
4. Release 14
5. 3GPP. TS 29.214 Policy and charging control over Rx reference point (Release 14). htp://www.3gpp.org/DynaReport/29214.htm. 3GPP. TS 29.214 Policy and charging control over Rx reference point (Release 14). htp://www.3gpp.org/DynaReport/29214.htm.