Evolved node-b (enb), user equipment (ue) and methods of switching between direct and indirect communication for a relay arrangement

A computer-readable storage medium that stores instructions for execution by one or more processors to perform operations for communication by a User Equipment (UE), the UE configurable to operate as an eRelay UE, the operations to configure the one or more processors to:

• decode an uplink data packet received from an eRemote UE in accordance with a relay arrangement in which the eRelay UE operates as a relay between an Evolved Node-B (eNB) and the eRemote UE,
• wherein the eNB operates in a Third Generation Partnership Project (3GPP) Long Term Evolution (LTE) network;
• encode the uplink data packet for transmission to the eNB;
• decode, from the eNB, a control message that indicates a handover of the eRelay UE from the 3GPP LTE network to another network in accordance with a circuit switched fallback (CSFB) procedure or a single radio voice call continuity (SRVCC) procedure;
• and
• based on the handover from the 3GPP LTE network to the other network:
• encode, for transmission to the eRemote UE, a PC5 request message to indicate that the relay arrangement is to be disabled.

An apparatus of a User Equipment (UE), the UE configurable to operate as an eRemote UE, the apparatus comprising:

• memory;
• and processing circuitry, configured to:
• decode a downlink data packet received from an Evolved Node-B (eNB) as part of a direct communication between the eRemote UE and the eNB;
• decode, from an eRelay UE, a PC5 connection message to establish a relay arrangement in which the eRelay UE is to operate as a relay;
• encode, for transmission to an eRelay UE, an information request message that indicates an intention, of the eRemote UE, to communicate with the eRelay UE in accordance with the relay arrangement;
• decode, from the eRelay UE, an information response message that indicates an identifier of the eRelay UE, wherein the memory is configured to store the identifier of the eRelay UE;
• and
• encode, for transmission to the eNB to be forwarded to a mobility management entity (MME), a tracking area update (TAU) message that indicates the intention, of the eRemote UE, to communicate with the eRelay UE in accordance with the relay arrangement.