Method and device for performing communication on basis of beam in wireless communication system

A first device, comprising:

• at least one transceiver;
• at least one processor;
• and
• at least one memory connected to the at least one processor and storing instructions that, based on being executed by the at least one processor, cause the first device to perform operations comprising:
• obtaining information related to a radio link monitoring related to a beam failure;
• performing the radio link monitoring for a second device;
• resetting a medium access control (MAC) entity of the first device;
• and
• performing, based on the MAC entity of the first device has been reset, and based on that the information related to the radio link monitoring related to beam failure is set to true,
• the radio link monitoring for the second device.

A processing device, comprising:

• at least one processor;
• and
• at least one memory connected to the at least one processor and storing instructions that, based on being executed by the at least one processor, cause a first device to perform operations comprising:
• obtaining information related to a radio link monitoring related to a beam failure;
• performing the radio link monitoring for a second device;
• resetting a medium access control (MAC) entity of the first device;
• and
• performing, based on the MAC entity of the first device has been reset, and based on that the information related to the radio link monitoring related to beam failure is set to true,
• the radio link monitoring for the second device.