At operation 340, the base station may transmit indication regarding whether a DL-based UL beam association has been activated to the terminal. The indication may indicate the activation of a DL-based UL beam association. For example, the base station may transmit information indicating whether a DL beam to be used for UL transmission is a DL CSI-RS, an SSB or an SRS. For a detailed operation, reference is made to the method of transmitting indication regarding whether a DL-based UL beam association has been activated in the first embodiment. If the DL-based UL beam association has been activated, the base station may transmit DL BM-based UL BPL indication to the terminal at operation 345. For example, the base station may transmit information on the resource indicator of a DL beam to be used for UL transmission to the terminal. For a detailed method of transmitting the UL BPL indication, reference is made to the operation of the first embodiment. Operation 340 and operation 345 are different in the contents of the indications. The indications of operations 340 and 345 may be included in a single message and transmitted or may be included in different messages and transmitted.

After operation 335 or operation 345, the base station may receive an UL signal, data or an RS from the terminal based on the indicated UL BPL at operation 350.

FIG. 3B is a diagram showing a procedure of a terminal for a DL-based UL beam association according to a first embodiment of the disclosure.