There is provided a UE for performing communication, the UE comprising: at least one transceiver; at least one processor configured to use CA based on two NR operating bands; and at least one computer memory operably connectable to the at least one processor and storing instructions that, based on being executed by the at least one processor, perform operations comprising: transmitting an uplink signal based on NR operating band n1 or n3; receiving a downlink signal based on the NR operating band n1 or n3.