16.23.2 Architecture

The NG-RAN overall architecture as depicted in section 4.1 is applicable for Ambient IoT along the following adaptations and additions:

• For the sake of supporting the provision of A-IoT services, the involved gNBs are enabled to support A-IoT, specifically, the gNB supports communication with A-IoT devices by means of A-IoT radio.
• A gNB may or may not only support communication with A-IoT devices by means of A-IoT radio.
• A gNB serves one or multiple readers.
• A gNB is aware of the mapping relationship between A-IoT Areas and readers by means of OAM configuration.
• An A-IoT Area may include readers belonging to the same or different gNB.
• One reader only belongs to one gNB.
• One reader can be mapped to one or multiple A-IoT Areas.
• As specified in TS 23.369 [68], the A-IoT CN node which the gNB connects to is either the AIOTF (in case of direct connectivity with the AIOTF) or the AMF (in case of indirect connectivity with the AIOTF). A gNB is aware of direct connectivity with the AIOTF via OAM.

NOTE: A deployment with both direct connectivity and indirect connectivity is not expected.

• In this version of the specification, A-IoT specific information is transported between the gNB and the A-IoT CN node via the NG-C interface, the protocol stack in section 4.3.1.2 applies. In case of indirect connectivity with the AIOTF, A-IoT specific information is transferred transparently via the AMF.
• In this version of the specification, no A-IoT specific communication takes place between gNBs.
• In this version of the specification, split gNB architecture is not supported.

The AIOTF may request the gNB to perform an A-IoT operation within a specific area (requested service area). The requested service area may be indicated by means of a list of A-IoT Areas and/or a list of readers. The A-IoT Area is represented by an A-IoT Area ID. The reader is represented by a Reader ID as specified in TS 38.413 [26].

The AIOTF is aware of the area within which the gNB supports provision of A-IoT services by means of OAM configuration. This area may be represented as A-IoT Areas and/or the reader ID list supported by the gNB.

The AIOTF may also be aware of the reader’s location by means of OAM configuration.

The AIOTF is aware of the mapping relationship among gNBs, readers and A-IoT areas by means of OAM configuration, as needed.

For Ambient IoT, the following applies in addition to the Network Identities as described in clause 8.2:

• The A-IoT Area ID is constructed from the PLMN identity (may be present together with a NID) the A-IoT area belongs to and the A-IoT Area Code.