Operation method and device related to measurement and relay selection in ue-to-ue relay in wireless communication system

A source remote user equipment (UE) in UE-to-UE relay in a wireless communication system, comprising:

• at least one processor;
• and
• at least one computer memory operably connectable to the at least one processor and storing instructions which, when executed, cause the at least one processor to perform operations,
• wherein the operations include:
• establishing a PC5 link with a first relay UE;
• establishing an end-to-end link with a target remote UE via the first relay UE;
• performing measurements for a plurality of candidate relay UEs;
• transmitting ID information about at least one candidate relay UE among the plurality of candidate relay UEs to the target remote UE;
• receiving a measurement result of the target remote UE for the at least one candidate relay UE from the target remote UE;
• and
• selecting a second relay UE based on the measurement result.

A non-transitory computer-readable storage medium storing at least one program code including instructions which, when executed by at least one processor, cause the at least one processor to perform operations for a source remote user equipment (UE),

• wherein the operations include:
• establishing a PC5 link with a first relay UE;
• establishing an end-to-end link with a target remote UE via the first relay UE;
• performing measurements for a plurality of candidate relay UEs;
• transmitting ID information about at least one candidate relay UE among the plurality of candidate relay UEs to the target remote UE;
• receiving a measurement result of the target remote UE for the at least one candidate relay UE from the target remote UE;
• and
• selecting a second relay UE based on the measurement result.