16.12.5.2 Radio Link Failure

The L2 U2N Remote UE in RRC_CONNECTED suspends Uu RLM (as described in clause 9.2.7) when connected to the gNB via a L2 U2N Relay UE.

The L2 U2N Relay UE declares Uu/PC5 Radio Link Failure (RLF) following the same criteria as described in clause 9.2.7.

After Uu/PC5 RLF is declared, the L2 U2N Relay UE takes the following action on top of the actions described in clause 9.2.7:

• a PC5-RRC message can be used for sending an indication to its connected L2 child UE(s), which may trigger RRC connection re-establishment for L2 child UE; or
• indicating to upper layer to trigger PC5 unicast link release.

Upon detecting PC5 RLF or PC5 link release, the L2 U2N Remote UE may trigger RRC connection re-establishment.