E-UTRAN may determine the NCL as follows:
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If the "SRVCC operation possible" indication is set to "true" (i.e. both EPC and UE are SRVCC capable), then:
-
if there is an established QCI=1 bearer for this UE, then 1x cells may be included as candidate target cells in the NCL;
-
if there is no established QCI=1 bearer for this UE, then 1x cells are not included in the NCL.
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If the "SRVCC operation possible" indication is not set, then 1x cells are not included in the NCL.
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:
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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;
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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.
Similar logic may be used as in
clause A.2 by replacing E-UTRAN with UTRAN.
GERAN/UTRAN may determine the NCL, as well as the need to signal a CS to PS SRVCC indication, as follows:
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If the "CS to PS SRVCC operation possible" indication is set to "true" (i.e. both the network and UE are CS to PS SRVCC capable, and a valid IMS registration via PS still exists), and the UE has indicated in Radio Access Capabilities support for CS to PS SRVCC to this RAT, then VoIP-capable cells may be included as candidate target cells in the NCL, regardless of the presence of an established TS 11 bearer for this UE. Moreover:
-
if there is an established TS 11 bearer for this UE and the selected target cell is VoIP-incapable, then GERAN/UTRAN does not indicate that the handover is for CS to PS in the Handover Required message;
-
if there is an established TS 11 bearer for this UE and the selected target cell is VoIP-capable, then GERAN/UTRAN indicates that the handover is for CS to PS in the Handover Required message;
-
if there is no established TS 11 bearer for this UE, then GERAN/UTRAN does not indicate that the handover is for CS to PS in the Handover Required message;
-
If the "CS to PS SRVCC operation possible" indication is not set (i.e. either the network or UE is not CS to PS SRVCC capable, and a valid IMS registration via PS still exists), or the UE has not indicated in Radio Access Capabilities support for CS to PS SRVCC to this RAT, then GERAN/UTRAN does not indicate that the handover for CS to PS in the Handover Required message. Moreover:
-
if there is an established TS 11 bearer for this UE, then VoIP-capable cells are not be included in the NCL;
-
if there is no established TS 11 bearer for this UE, then VoIP-capable cells may be included in the NCL.