5.35.3 Data handling and QoS support with IAB

Control plane and user plane protocol stacks for IAB operation are defined in TS 38.300 [27].

QoS management for IAB can remain transparent to the 5GC. If NG-RAN cannot meet a QoS requirement for a QoS Flow to IAB-related resource constraints, the NG-RAN can reject the request using procedures defined in TS 23.502 [3].

The IAB-UE function can establish a PDU session or PDN connection, e.g. for OAM purpose (protocol stack not shown here). In that case, the IAB-UE obtains an IP address/prefix from the core network using normal UE procedures. The IAB-UE's IP address is different from that of the IAB-node's gNB DU IP address.

NOTE: For OAM traffic, based on their specific requirements, operators can select QoS characteristics and reference them by pre-configured 5QI(s) or using signalled QoS characteristics within the operator's network.