Section: 5.3.5.8.2 Inability to comply with RRCReconfiguration
Content: NOTE 00: The UE behaviour specified in this clause does not apply to the following, and the UE ignores, i.e. does not take an action on and does not store, the fields that it does not support or does not comprehend: - The fields in ServingCellConfigCommon that are defined in Rel-16 and later. - The fields of searchSpaceMCCH and searchSpaceMTCH in PDCCH-ConfigCommon that are defined in Rel-17 and later. The UE shall: 1> if the UE is in (NG)EN-DC: 2> if the UE is unable to comply with (part of) the configuration included in the RRCReconfiguration message received over SRB3; 3> if the RRCReconfiguration message was received as part of ConditionalReconfiguration: 4> continue using the configuration used prior to when the inability to comply with the RRCReconfiguration message was detected; 3> else: 4> continue using the configuration used prior to the reception of RRCReconfiguration message; 3> if MCG transmission is not suspended: 4> initiate the SCG failure information procedure as specified in clause 5.7.3 to report SCG reconfiguration error, upon which the connection reconfiguration procedure ends; 3> else: 4> initiate the connection re-establishment procedure as specified in TS 36.331[ Evolved Universal Terrestrial Radio Access (E-UTRA); Radio Resource Control (RRC); Protocol specification ]  [10], clause 5.3.7, upon which the connection reconfiguration procedure ends; 2> else, if the UE is unable to comply with (part of) the configuration included in the RRCReconfiguration message received over SRB1; 3> if the RRCReconfiguration message was received as part of ConditionalReconfiguration: 4> continue using the configuration used prior to when the inability to comply with the RRCReconfiguration message was detected; 3> else: 4> continue using the configuration used prior to the reception of RRCReconfiguration message; 3> initiate the connection re-establishment procedure as specified in TS 36.331[ Evolved Universal Terrestrial Radio Access (E-UTRA); Radio Resource Control (RRC); Protocol specification ]  [10], clause 5.3.7, upon which the connection reconfiguration procedure ends. 1> else if RRCReconfiguration is received via NR (i.e., NR standalone, NE-DC, or NR-DC): 2> if the UE is unable to comply with (part of) the configuration included in the RRCReconfiguration message received over SRB3; NOTE 0: This case does not apply in NE-DC. 3> if the RRCReconfiguration message was received as part of ConditionalReconfiguration; or, 3> if the RRCReconfiguration message was received as part of ltm-Config: 4> continue using the configuration used prior to when the inability to comply with the RRCReconfiguration message was detected; 3> else: 4> continue using the configuration used prior to the reception of RRCReconfiguration message; 3> if MCG transmission is not suspended: 4> initiate the SCG failure information procedure as specified in clause 5.7.3 to report SCG reconfiguration error, upon which the connection reconfiguration procedure ends; 3> else: 4> initiate the connection re-establishment procedure as specified in clause 5.3.7, upon which the connection reconfiguration procedure ends; 2> else if the UE is unable to comply with (part of) the configuration included in the RRCReconfiguration message received over the SRB1 or if the upper layers indicate that the nas-Container is invalid: NOTE 0a: The compliance also covers the SCG configuration carried within octet strings e.g. field mrdc-SecondaryCellGroupConfig. I.e. the failure behaviour defined also applies in case the UE cannot comply with the embedded SCG configuration or with the combination of (parts of) the MCG and SCG configurations. NOTE 0b: The compliance also covers the V2X sidelink configuration carried within an octet string, e.g. field sl-ConfigDedicatedEUTRA. I.e. the failure behaviour defined also applies in case the UE cannot comply with the embedded V2X sidelink configuration. 3> if the RRCReconfiguration message was received as part of ConditionalReconfiguration; or, 3> if the RRCReconfiguration message was received as part of ltm-Config: 4> continue using the configuration used prior to when the inability to comply with the RRCReconfiguration message was detected; 3> else: 4> continue using the configuration used prior to the reception of RRCReconfiguration message; 3> if AS security has not been activated: 4> perform the actions upon going to RRC_IDLE as specified in 5.3.11, with release cause 'other' 3> else if AS security has been activated but SRB2 and at least one DRB or multicast MRB or, for IAB and NCR, SRB2, have not been setup: 4> perform the actions upon going to RRC_IDLE as specified in 5.3.11, with release cause 'RRC connection failure'; 3> else: 4> initiate the connection re-establishment procedure as specified in 5.3.7, upon which the reconfiguration procedure ends; 1> else if RRCReconfiguration is received via other RAT (Handover to NR failure): 2> if the UE is unable to comply with any part of the configuration included in the RRCReconfiguration message or if the upper layers indicate that the nas-Container is invalid: 3> perform the actions defined for this failure case as defined in the specifications applicable for the other RAT. NOTE 1: The UE may apply above failure handling also in case the RRCReconfiguration message causes a protocol error for which the generic error handling as defined in clause 10 specifies that the UE shall ignore the message. NOTE 2: If the UE is unable to comply with part of the configuration, it does not apply any part of the configuration, i.e. there is no partial success/failure. NOTE 3: It is up to UE implementation whether the compliance check for an RRCReconfiguration received as part of ConditionalReconfiguration is performed upon the reception of the message or upon CHO, CPA, CPC, and subsequent CPAC execution (when the message is required to be applied). NOTE 4: It is up to UE implementation whether the compliance check for an RRCReconfiguration message received as part of an LTM-Config IE is performed upon the reception of the message or during an LTM cell switch procedure (when the message is required to be applied).