Methods for coordinated relay selection in wtru-wtru relays

A first wireless transmit/receive unit WTRU comprising:

• a processor configured to:
• receive configuration information, wherein the configuration information comprises a sidelink reference signal receive power (SL-RSRP) threshold and a time period associated with discovery solicitation;
• determine whether radio link failure (RLF) has occurred on a PC5 connection with a second WTRU or whether a SL-RSRP measurement on the PC5 connection is below the SL-RSRP threshold;
• based on a determination that RLF has occurred on the PC5 connection with the second WTRU, send a solicitation message or a link modification message, wherein the solicitation message or the link modification message comprises an indication of RLF detection on the PC5 connection;
• and
• based on a determination that the SL-RSRP measurement on the PC5 connection is below the SL-RSRP threshold, send the solicitation message to initiate relay selection after a determination that the first WTRU has not selected a relay WTRU for the PC5 connection during the time period associated with discovery.

A method implemented by a first wireless transmit/receive unit (WTRU), the method comprising:

• receiving configuration information, wherein the configuration information comprises a sidelink reference signal receive power (SL-RSRP) threshold and a time period associated with discovery solicitation;
• determining that radio link failure (RLF) has occurred on a PC5 connection with a second WTRU;
• and
• based on a determination that RLF has occurred on the PC5 connection with the second WTRU, sending a solicitation message or a link modification message, wherein the solicitation message or the link modification message comprises an indication of RLF detection on the PC5 connection.