The SRVCC Architecture for 3GPP2 1xCS reuses many existing elements in 3GPP2 X.S0042 [4] for 3GPP2 1xCS.
The SRVCC and vSRVCC Architectures for 3GPP E-UTRAN / UTRAN(HSPA) to 3GPP UTRAN/GERAN reuses the session transfer function defined for IMS in TS 23.237 for IMS service continuity. The MSC Server that is enhanced for SRVCC and vSRVCC may also be enhanced for ICS as defined in TS 23.292.
The SRVCC Architecture for CS to PS reuses the session transfer function defined for IMS in TS 23.237 for IMS service continuity. The MSC Server that is enhanced for CS to PS SRVCC is also enhanced for ICS as defined in TS 23.292.
The overall model and impacts to the various elements is provided in the following clauses.
This specification introduces an additional functional entity to those defined in the E-UTRAN architecture TS 23.402, called 1x CS SRVCC interworking solution function (3GPP2 1xCS IWS), see Figure 5.2.1-1.
This specification introduces an additional function to those defined in the E-UTRAN architecture TS 23.401 for SRVCC. This additional function is provided by the MSC Server (i.e., MSC Server enhanced for SRVCC).
This specification introduces an additional function to those defined in the UTRAN architecture TS 23.060 for SRVCC. This additional function is provided by the MSC Server (i.e., MSC Server enhanced for SRVCC).