4.2.2.1 General

5GS system architecture for AIoT supports the following connectivity to access an NG-RAN:

• Direct Connectivity: AIOTF communicates with NG-RAN directly.
• Indirect Connectivity via AMF: NG-RAN and the AIOTF communicate indirectly via an AMF.

Figure 4.2.2.1-1 depicts the complete non-roaming architecture showing the overall 5GS architecture for support of AIoT, including both the Indirect Connectivity and Direct Connectivity.

NOTE 1: For the sake of clarity and to depict the complete reference point architecture, the AMF, AIOT2 and N2 as depicted using dashed lines, as all deployments might not use them.

Figure 4.2.2.1-2 depicts the complete non-roaming AIoT system architecture, using the reference point representation.

NOTE 2: For the sake of clarity of the point-to-point diagrams, the AF and NRF have not been depicted. However, all depicted Network Functions can interact with the NRF as necessary.

NOTE 3: For clarity, the UDR and its connections with ADM, are not depicted in the point-to-point and service-based architecture diagrams. For more information on the ADM data storage architectures refer to clause 4.5.8.

NOTE 4: For the sake of clarity and to depict the complete reference point architecture, the AMF, AIOT3, N2 and AIOT2 as depicted using dashed lines, as all deployments might not use them.

The architectures in the following clauses showing parts of the overall AIoT architecture specific to each connectivity option:

• Direct Connectivity: the AIOTF uses AIOT2 to access NG-RAN, and is described in clause 4.2.2.2.
• Indirect Connectivity via AMF: the AIOTF uses an AMF which uses N2 to access NG-RAN, and is described in clause 4.2.2.3.

NOTE 5: A deployment that only uses, e.g. the Direct Connectivity only does not need to deploy the NFs, reference points and service-based interfaces associated with the Indirect Connectivity, and vice-versa.