The scope of the present document is to investigate solutions from architecture point of view to support single radio voice call continuity (SRVCC) from NG-RAN to UTRAN.
Issues to be resolved will be collected and documented in the TR with a possible resolution.
The following documents contain provisions which, through reference in this text, constitute provisions of the present document.
References are either specific (identified by date of publication, edition number, version number, etc.) or non specific.
For a specific reference, subsequent revisions do not apply.
For a non-specific reference, the latest version applies. In the case of a reference to a 3GPP document (including a GSM document), a non-specific reference implicitly refers to the latest version of that document in the same Release as the present document.
: "Vocabulary for 3GPP Specifications".
: "Single Radio Voice Call Continuity (SRVCC)".
: "IP Multimedia Subsystem (IMS) Service Continuity; Stage 2".
: "General Packet Radio Service (GPRS) enhancements for Evolved Universal Terrestrial Radio Access Network (E-UTRAN) access".
: "General Packet Radio Service (GPRS); Service description; Stage 2".
: "System Architecture for the 5G System".
For the purposes of the present document, the terms and definitions given in TR 21.905
apply. A term defined in the present document takes precedence over the definition of the same term, if any, in TR 21.905
For the purposes of the present document, the abbreviations given in TR 21.905
apply. An abbreviation defined in the present document takes precedence over the definition of the same abbreviation, if any, in TR 21.905
The following architectural assumptions apply:
Solutions shall not consider voice continuity from GERAN/UTRAN to NG-RAN.
Solutions shall not consider voice continuity from NG-RAN to GERAN.
Solutions shall not consider video service continuity between NG-RAN and GERAN/UTRAN.
Solutions shall not consider IP address preservation for PS service when UE moves between NG-RAN and GERAN/UTRAN.
Solutions shall not consider service continuity between 5GS and CDMA.