The present disclosure provides a method used in user equipment (UE). The method comprises: detecting that a radio link control (RLC) entity associated with a packet duplication bearer or packet duplication split bearer has reached a predetermined maximum number of retransmissions; and determining that a radio link associated with the RLC entity is unavailable or fails based on whether a cell associated with the RLC entity is a special cell (SpCell) or whether a cell group associated with the RLC entity includes an SpCell.