5G (NR) RAN Learning - Path Request in Handover (3)

3GPP defines the following in TS 38.413 regarding enhanced coverage restriction, extended connection time, V2X service authorization, and handover path request processing for sidelink aggregation terminals in the 5G system:

I. Enhanced Coverage Restriction and Extended Connection Time

• If the Path Switch Request Acknowledge (PATH SWITCH REQUEST ACKNOWLEDGE) message includes the Enhanced Coverage Restriction IE, the NG-RAN node SHOULD (if supported) store this information in the UE context and use it as defined in TS 23.501.

• If the Path Switch Request Acknowledge (PATH SWITCH REQUEST ACKNOWLEDGE) message includes the Extended Connected Time IE, the NG-RAN node SHOULD (if supported) use it as defined in TS 23.501.

• If the Path Switch Request Acknowledge (PATH SWITCH REQUEST ACKNOWLEDGE) message includes a UE Differentiation Information IE, the NG-RAN node (if supported) should store this information in the UE context for further use in accordance with TS 23.501.

II. NR V2X Service Authorization

• If the PATH SWITCH REQUEST ACKNOWLEDGE message includes an NR V2X Service Authorization IE, the NG-RAN node (if supported) should update its NR V2X service authorization information for the UE accordingly.

• If the NR V2X Service Authorization IE includes one or more IEs set to "Unauthorized," the NG-RAN node (if supported) should take steps to ensure that the UE no longer has access to the associated services.

• If the PATH SWITCH REQUEST ACKNOWLEDGE message includes an LTE V2X Service Authorization IE, the NG-RAN node (if supported) should update its LTE V2X service authorization information for the UE accordingly.If the LTE V2X Service Authorization IE contains one or more IEs set to "Unauthorized," the NG-RAN node (if supported) should take measures to ensure that the UE no longer has access to the associated services.

• If the NR A2X Service Authorization IE contains one or more IEs set to "Unauthorized," the NG-RAN node (if supported) should take measures to ensure that the UE no longer has access to the associated services.

• If the Path Switch Request Acknowledge (PATH SWITCH REQUEST ACKNOWLEDGE) message contains an LTE A2X Service Authorization IE, the NG-RAN node (if supported) should update its LTE A2X Service Authorization information for the UE accordingly.

• If the LTE A2X Service Authorization IE contains one or more IEs set to "Unauthorized," the NG-RAN node (if supported) should take measures to ensure that the UE no longer has access to the associated services.

III. Sidelink and Aggregation Processing

• If the PATH SWITCH REQUEST ACKNOWLEDGE message contains the NR UE Sidelink Aggregate Maximum Bit Rate IE, the NG-RAN node (if supported) shall perform the following operations:

1. Replace the previously provided UE Sidelink Aggregate Maximum Bit Rate (if available in the UE context) with the received value;
2. Use the received value for sidelink communications with the associated UE in NR V2X serving network scheduling mode.

• If the PATH SWITCH REQUEST ACKNOWLEDGE message contains the LTE UE Sidelink Aggregate Maximum Bit Rate IE, the NG-RAN node (if supported) shall perform the following operations:

1. Replace the previously provided UE Sidelink Aggregate Maximum Bit Rate (if available in the UE context) with the received value;
2. Use the received value for sidelink communications with the associated UE in LTE V2X serving network scheduling mode.

• If the PATH SWITCH REQUEST ACKNOWLEDGE message includes the NR A2X UE PC5 aggregate maximum bit rate IE, the NG-RAN node (if supported) shall perform the following operations:

1. Replace the previously provided NR A2X UE PC5 aggregate maximum bit rate (if available in the UE context) with the received value;
2. In network-scheduled mode, use the received value for NR A2X service sidelink communications for the associated UE.

• If the PATH SWITCH REQUEST ACKNOWLEDGE message includes the LTE A2X UE PC5 aggregate maximum bit rate IE, the NG-RAN node (if supported) shall perform the following operations:

1. Replace the previously provided LTE A2X UE PC5 aggregate maximum bit rate (if available in the UE context) with the received value;
2. In network-scheduled mode, use the received value for LTE A2X service sidelink communications for the associated UE.