A.2 SRVCC from E-UTRAN to GERAN / UTRAN

23.2163GPPRelease 16Single Radio Voice Call Continuity (SRVCC)Stage 2TS

E-UTRAN may determine the NCL, as well as the need to signal a SRVCC indication, as follows:

– If the "SRVCC operation possible" indication is set to "true" (i.e. both EPC and UE are SRVCC capable) and the UE has indicated in Radio Access Capabilities support for SRVCC to the target RAT, then VoIP-incapable cells may be included as candidate target cells in the NCL, regardless of the presence of an established QCI=1 bearer for this UE. Moreover:

– if there is an established QCI=1 bearer for this UE and the selected target cell is VoIP-capable and the UE has indicated in Radio Access Capabilities support for PS Voice over UTRAN, then E-UTRAN does not include a SRVCC indication in the Handover Required message;

– if there is an established QCI=1 bearer for this UE and the selected target cell is VoIP-incapable, or the UE has indicated in Radio Access Capabilities no support for PS Voice over UTRAN, then E-UTRAN includes a SRVCC indication in the Handover Required message;

– if there is no established QCI=1 bearer for this UE, then E-UTRAN does not include a SRVCC indication in the Handover Required message;

– If the "SRVCC operation possible" indication is not set, or the UE has not indicated in Radio Access Capabilities support for SRVCC to the target RAT, then E-UTRAN does not include a SRVCC indication in the Handover Required message. Moreover:

– if there is an established QCI=1 bearer for this UE, then VoIP-incapable cell are not be included in the NCL;

– if there is no established QCI=1 bearer for this UE, then VoIP-incapable cells may be included in the NCL.