Method and apparatus for setting up relay link in wireless communication system

A source relay terminal in a wireless communication system, the source relay terminal comprising:

• a transceiver;
• and
• at least one processor operably coupled to the transceiver,
• wherein the at least one processor is configured to:
• provide relay communication with a remote terminal by using an internet protocol (IP) address of the remote terminal for a first link,
• receive, from the remote terminal, a first message for notifying relay link change from the first link to a second link, and
• transmit, to a base station, a second message for assisting a link change from the first link to a second link in response to reception of the first message,
• wherein the second message comprises an internet protocol (IP) address of the remote terminal for the first link,
• wherein the first link is established between the remote terminal and the source relay terminal,
• wherein the second link is established between the remote terminal and a target relay terminal, and
• wherein packets for the remote terminal are stored in the base station through a binding update performed by the base station, in response reception of the second message by the base station.

A target relay terminal in a wireless communication system, the target relay terminal comprising:

• a transceiver;
• and
• at least one processor operably coupled to the transceiver,
• wherein the at least one processor is configured to:
• receive a relay request message from a remote terminal that is being performing relay communication with a source relay terminal through a first link,
• receive, from a base station, a message for assisting a link change from the first link to a second link, the message comprising an internet protocol (IP) address of the remote terminal for the first link,
• perform an IP duplication check for identifying an IP duplication between the IP address of the remote terminal for the first link and an IP address of another remote terminal allocated by the target relay terminal, in response to receiving the message,
• transmitting, to the remote terminal, an address identification message for notifying an IP address of the remote terminal for the second link that is identical to the IP address of the remote terminal for the first link, in case that the IP duplication is not identified, and
• provide relay communication with the remote terminal by using the IP address for the second link,
• wherein the first link is established between the remote terminal and the source relay terminal, and
• wherein the second link is established between the remote terminal and the target relay terminal.