Voice call continuity allows users to move between the CS domain and the IP Connectivity Access Network (e.g.,
WLAN interworking) with home IM CN subsystem functionality.
This TS provides the protocol details for voice call continuity between the IP Multimedia (IM) Core
Network (CN) subsystem based on the Session Initiation Protocol (SIP) and the Session Description Protocol (SDP) and the protocols of the 3GPP Circuit-Switched (CS) domain (CAP, MAP, ISUP, BICC and the NAS call control protocol
for the CS access).
This document makes no VCC specific enhancements to SIP, SIP events or SDP, beyond those specified in
This TS is applicable to User Equipment (UEs), Application Servers (AS) and Media Gateway Control
Functions (MGCF) providing voice call continuity capabilities.
Note: No upgrade to Rel-8 due to change of approach to VCC.