Layer 2 Relay Protocols and Mobility Relay Method

A remote user equipment (UE) for use in a wireless communication network, the remote UE comprising:

• a memory;
• and
• one or more processors coupled to the memory, the one or more processors configured to, when executing instructions stored in the memory, cause the UE to:
• determine to communicate a layer-2 (L2) packet data unit (PDU) to a base station via a relay UE, wherein the remote UE communicates with the relay UE using a sidelink network interface;
• and
• transmit, to the relay UE, the L2 PDU based on a mapping between:
• (i) a radio bearer identifier of a radio bearer between the base station and the remote UE, and (ii) a logical channel identifier used on the sidelink network interface.

A method to be performed by a relay user equipment (UE), the method comprising:

• receiving, from a base station, a layer-2 (L2) packet data unit (PDU) comprising a header that includes a remote UE identifier of a remote UE;
• determining, based on the remote UE identifier, to transmit the L2 PDU to the remote UE via a sidelink network interface;
• and
• transmitting, to the remote UE, the L2 PDU based on a mapping between:
• (i) a logical channel identifier used on a Uu interface between the base station and the relay UE, and (ii) a radio bearer identifier of a radio bearer between the base station and the remote UE.