SRVCC

jianglinhua

Release 8:

Basic SRVCC from LTE PS to UTRAN/GERAN CS with/without PS HO/DTM;

Release 9:

IMS Emergence Call SRVCCfrom LTE PS to UTRAN/GERAN CS;

Release 10:

aSRVCC: support SRVCCPS-CS transfer during alerting phase;

eSRVCC: support mid-callfeature during SRVCC HO procedure, MSC Server assisted mid-call feature enablespacket switched (PS) - circuit switched (CS) Access Transfer for UEs not usingIMS Centralized Service (ICS) capabilities, while preserving the provision ofmid-call services (inactive sessions or sessions using the Conference service).

Release 11:

bSRVCC means SRVCC before ringing;

vSRVCC means video call SRVCC from LTE PS to 3G(UTRAN) CS;

rSRVCC means reverse SRVCC HO from UTRAN/GERAN CS back to LTE PS;

SRVCC during upgrading from VoLTE call to video call.