5.13 Configuration of Single Radio Voice Call Continuity (SRVCC)

23.0023GPPNetwork architectureRelease 17TS

5.13.1 E-UTRAN/UTRAN (HSPA) to UTRAN or GERAN SRVCC architecture

Single Radio Voice Call Continuity (PS to CS) refers to continuity between IMS over PS access and CS calls that are anchored in IMS when the UE is capable of transmitting/receiving on only one of those access networks at a given time. PS to CS SRVCC is specified in TS 23.216 [83]. The following figures 5.13, 5.13a and 5.13b show the entities involved in PS to CS SRVCC.

Figure 5.13: SRVCC architecture for E-UTRAN to 3GPP UTRAN/GERAN

Figure 5.13a: SRVCC architecture for UTRAN (HSPA) to 3GPP UTRAN/GERAN with Gn based SGSN

Figure 5.13b: PS to CS SRVCC architecture for UTRAN (HSPA) to 3GPP UTRAN/GERAN with S4 based SGSN

NOTE 1: The above figures only show the necessary components related to MSC Server enhanced with SRVCC.

NOTE 2: MSC Server shown in the above figures are enhanced for SRVCC.

NOTE 3: This architecture also applies to roaming scenario (i.e., S8, S6a are not impacted due to SRVCC).

NOTE 4: The MSC Server enhanced with SRVCC may not be the final target MSC which connects to the target cell.

5.13.2 UTRAN/GERAN to E-UTRAN or UTRAN (HSPA) SRVCC architecture

CS to PS Single Radio Voice Call Continuity refers to continuity between a CS call and IMS call over PS access that are anchored in IMS when the UE is capable of transmitting/receiving on only one of those access networks at a given time. CS to PS SRVCC is specified in TS 23.216 [83]. The following figures 5.13c, 5.13d and 5.13e show the entities involved in CS to PS SRVCC.

NOTE 1: The above figure only shows the necessary components related to MSC Server enhanced for CS to PS SRVCC.

NOTE 2: MSC Server shown in the figure is enhanced for CS to PS SRVCC.

NOTE 3: This architecture also applies to roaming scenario (i.e. S8, S6a are not impacted due to CS to PS SRVCC).

Figure 5.13c: CS to PS SRVCC architecture for UTRAN/GERAN to E-UTRAN

Figure 5.13d: CS to PS SRVCC architecture for UTRAN/GERAN to UTRAN (HSPA) with Gn based SGSN

NOTE 1: The above figures only show the necessary components related to MSC Server enhanced with CS to PS SRVCC.

NOTE 2: MSC Server shown in the above figures are enhanced for CS to PS SRVCC.

NOTE 3: This architecture also applies to roaming scenario.

Figure 5.13e: CS to PS SRVCC architecture for UTRAN/GERAN to UTRAN (HSPA) with S4 based SGSN