Method and apparatus for transmitting/receiving wireless signal in wireless communication system

A device comprising:

• a memory configured to store instructions;
• and
• a processor configured to perform operations by executing the instructions,
• wherein the operations performed by the processor comprise:
• performing an indirect path configuration as a relay device in an indirect path between a second device and a network;
• storing data units received from the second device in an uplink buffer configured in the memory;
• and
• performing, as the relay device in the indirect path, uplink data unit transmission to a node of the network based on the data units stored in the uplink buffer,
• wherein, upon an indirect path release or a bearer release related to the indirect path for handover of the second device:
• the uplink data unit transmission to the node is performed during a first time duration based on the data units stored in the uplink buffer, and
• the data units still stored in the uplink buffer are discarded after the first time duration.