Provided is a method for a user equipment (UE). The UE obtains a physical uplink control channel (PUCCH) secondary cell (SCell) activation command from a primary cell (PCell) or primary secondary-cell-group cell (PSCell). The PUCCH SCell activation command is used for an PUCCH SCell activation of a target PUCCH SCell for the UE. The UE performs PUCCH SCell activation operations associated with a valid timing advance (TA) and the PUCCH SCell activation command. TA is considered to be a valid TA when the TA meets a preset criterion. The UE generates a channel state information (CSI) report for transmission to at least one of the PCell, PSCell and the target PUCCH SCell. The CSI report indicates that the PUCCH SCell activation is completed.