System information delivery for layer-2-based sidelink relay

A method for a user equipment (UE) comprising:

• establishing a sidelink connection with a relay UE in a wireless network, wherein the relay UE is connected with a gNB in the wireless network;
• configuring a layer-2 (L2)-based sidelink relay path between the UE and the gNB, wherein the sidelink is a relay link in the relay path;
• sending, by the UE, a system information (SI) Request message to the relay UE through the sidelink in a PC5-radio resource control (RRC) message to request a set of system information blocks (SIBs);
• and
• receiving, from the relay UE, the requested set of SIBs in a PC5-RRC SI Update message through the sidelink of the configured L2-based sidelink relay path, wherein the PC5-RRC SI Update message is a PC5 unicast message, and wherein the PC5 unicast RRC message is based on an Uu-RRC broadcast SI Update message from the gNB in response to the SI Request message from the remote UE and a subsequent PC5-RRC SI Request message indicating a set of SIBs requested from the remote UE.

A user equipment (UE), comprising:

• a transceiver that transmits and receives radio frequency (RF) signal in a wireless network;
• a sidelink handler that establishes a sidelink connection with a remote UE in the wireless network;
• a relay path handler that configures a layer-2 (L2)-based sidelink relay path between the remote UE and a gNB in the wireless network, wherein the sidelink is a relay link in the relay path;
• a system information (SI) sender that sends an SI Request destined to the gNB to request a set of system information blocks (SIBs) for the remote UE;
• and
• a SI handler that sends the requested set of SIBs in a PC5-RRC SI Update message through the sidelink of the configured L2-based sidelink relay path to the remote UE, wherein the PC5-RRC SI Update message is a PC5 unicast message, and wherein the PC5 unicast RRC message is based on an Uu-RRC broadcast SI Update message from the gNB in response to the SI Request message from the remote UE and a subsequent PC5-RRC SI Request message indicating a set of SIBs requested from the remote UE.