Section: 5.3.5.8.3 T304 expiry (Reconfiguration with sync Failure) or T420 expiry (Path switch failure)
Content: The UE shall: 1> if T304 of the MCG expires; or 1> if T420 expires; or, 1> if the target L2 U2N Relay UE (i.e., the UE indicated by targetRelayUE-Identity in the received RRCReconfiguration message containing reconfigurationWithSync indicating path switch as specified in 5.3.5.5.2) changes its serving PCell before path switch: 2> release dedicated preambles provided in rach-ConfigDedicated if configured; 2> release dedicated msgA PUSCH resources provided in rach-ConfigDedicated if configured; 2> if any DAPS bearer is configured, and radio link failure is not detected in the source PCell, according to clause 5.3.10.3: 3> reset MAC for the target PCell and release the MAC configuration for the target PCell; 3> for each DAPS bearer: 4> release the RLC entity or entities as specified in TS 38.322[ NR; Radio Link Control (RLC) protocol specification ]  [4], clause 5.1.3, and the associated logical channel for the target PCell; 4> reconfigure the PDCP entity to release DAPS as specified in TS 38.323[ NR; Packet Data Convergence Protocol (PDCP) specification ]  [5]; 3> for each SRB: 4> if the masterKeyUpdate was not received: 5> configure the PDCP entity for the source PCell with state variables continuation as specified in TS 38.323[ NR; Packet Data Convergence Protocol (PDCP) specification ]  [5]; 4> release the PDCP entity for the target PCell; 4> release the RLC entity as specified in TS 38.322[ NR; Radio Link Control (RLC) protocol specification ]  [4], clause 5.1.3, and the associated logical channel for the target PCell; 4> trigger the PDCP entity for the source PCell to perform SDU discard as specified in TS 38.323[ NR; Packet Data Convergence Protocol (PDCP) specification ]  [5]; 4> re-establish the RLC entity for the source PCell; 3> release the physical channel configuration for the target PCell; 3> discard the keys used in target PCell (the KgNB key, the KRRCenc key, the KRRCint key, the KUPint key and the KUPenc key), if any; 3> resume suspended SRBs in the source PCell; 3> for each non-DAPS bearer: 4> revert back to the UE configuration used for the DRB or multicast MRB in the source PCell, includes PDCP, RLC states variables, the security configuration and the data stored in transmission and reception buffers in PDCP and RLC entities ; 3> revert back to the UE measurement configuration used in the source PCell; 3> store the handover failure information in VarRLF-Report as described in the clause 5.3.10.5; 3> initiate the failure information procedure as specified in clause 5.7.5 to report DAPS handover failure. 2> else: 3> revert back to the UE configuration used in the source PCell; 3> if the associated T304 was not initiated upon cell selection performed while timer T311 was running, as defined in clause 5.3.7.3: 4> store the handover failure information in VarRLF-Report as described in the clause 5.3.10.5; 3> initiate the connection re-establishment procedure as specified in clause 5.3.7. NOTE 1: In the context above, "the UE configuration" includes state variables and parameters of each radio bearer. 1> else if T304 of a secondary cell group expires: 2> if MCG transmission is not suspended: 3> release dedicated preambles provided in rach-ConfigDedicated, if configured; 3> release dedicated msgA PUSCH resources provided in rach-ConfigDedicated, if configured; 3> initiate the SCG failure information procedure as specified in clause 5.7.3 to report SCG reconfiguration with sync failure, upon which the RRC reconfiguration procedure ends; 2> else: 3> if the UE is in NR-DC: 4> initiate the connection re-establishment procedure as specified in clause 5.3.7; 3> else (the UE is in (NG) EN-DC): 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; 1> else if T304 expires when RRCReconfiguration is received via other RAT (HO to NR failure): 2> reset MAC; 2> perform the actions defined for this failure case as defined in the specifications applicable for the other RAT. NOTE 2: In this clause, the term 'handover failure' has been used to refer to 'reconfiguration with sync failure'.