Content for TS 23.369 Word version: 19.1.0

4 Architecture model and concepts p. 8

4.1 General concept p. 8

AIoT is a service that can be provided by the 5GS system to support Ambient power-enabled IoT devices that are powered by energy harvesting, being either battery-less or with limited energy storage capability (e.g. using a capacitor) and the energy is provided through the harvesting of radio waves, light, motion, heat, or any other suitable power source.

The 5GS System architecture for AIoT include the following functions and procedures for:

AIoT Device identification;
AIoT Device inventory;
Providing to, and obtaining from, an AIoT Device application data.
Disabling AIoT Devices.

4.2 Architecture p. 8

4.2.1 General p. 8

The 5GS System architecture for AIoT includes core network functions, different AIoT Reader architectures and AIoT Devices. The different AIoT Reader architectures allow for different deployment options. The following AIoT Reader architectures are defined:

NG- RAN (which supports AIoT Reader), which includes either a direct connectivity between NG-RAN and the AIOTF or an indirect connectivity between NG-RAN and the AIOTF via an AMF.

The NG-RAN in this specification refers to the gNB which supports AIoT related functionalities, as specified in TS 38.300. The gNB may only support communication with AIoT Devices.

The architecture for Network Exposure Function, using reference point representation, defined in clause 4.2.3 of TS 23.501 is applicable for AIoT, with a southbound interface from the NEF to AIOTF.

4.2.2 Architecture for NG-RAN connectivity p. 9

4.2.2.1 General p. 9

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.

Copy of original 3GPP image for 3GPP TS 23.369, Fig. 4.2.2.1-1: Non-roaming AIoT System Architecture

Figure 4.2.2.1-1: Non-roaming AIoT System Architecture
(⇒ copy of original 3GPP image)

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

Copy of original 3GPP image for 3GPP TS 23.369, Fig. 4.2.2.1-2: Non-roaming AIoT System Architecture (RAN Readers) in reference point representation

Figure 4.2.2.1-2: Non-roaming AIoT System Architecture (RAN Readers) in reference point representation
(⇒ copy of original 3GPP image)

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.

4.2.2.2 Direct connectivity between AIOTF and NG-RAN p. 10

In the Direct Connectivity architecture, the AIOTF uses AIOT2 to communicate directly with NG-RAN.

Figure 4.2.2.2-1 depicts the AIoT architecture, using the service-based interfaces, showing only the parts of the AIoT architecture for an AIOTF connecting to NG-RAN directly. The remaining parts of the AIoT architecture shown in Figure 4.2.2.1-1 remain unchanged.

Copy of original 3GPP image for 3GPP TS 23.369, Fig. 4.2.2.2-1: NG- RAN - AIOT Direct connectivity Architecture

Figure 4.2.2.2-1: NG- RAN - AIOT Direct connectivity Architecture
(⇒ copy of original 3GPP image)

Figure 4.2.2.2-2 depicts the AIoT architecture, using the reference point representation, showing only the parts of the AIoT architecture for an AIOTF access NG-RAN. The remaining parts of the AIoT architecture shown in Figure 4.2.2.1-2 remain unchanged.

Copy of original 3GPP image for 3GPP TS 23.369, Fig. 4.2.2.2-2: NG-RAN - AIOT Direct connectivity Architecture in reference point representation

Figure 4.2.2.2-2: NG-RAN - AIOT Direct connectivity Architecture in reference point representation
(⇒ copy of original 3GPP image)

4.2.2.3 Indirect connectivity between AIOTF and NG-RAN via an AMF p. 11

Figure 4.2.2.3-1 depicts the AIoT architecture, using the service-based interfaces showing only the parts of the AIoT architecture for an AIOTF connects indirectly to NG-RAN via an AMF. The remaining parts of the AIoT Architecture shown in Figure 4.2.2.1-1 remain unchanged.

Copy of original 3GPP image for 3GPP TS 23.369, Fig. 4.2.2.3-1: NG-RAN - AIOT Indirect connectivity Architecture

Figure 4.2.2.3-1: NG-RAN - AIOT Indirect connectivity Architecture
(⇒ copy of original 3GPP image)

Figure 4.2.2.3-2 depicts the AIoT architecture, using the reference point representation showing only the parts of the AIoT architecture for an AIOTF connects to NG-RAN via an AMF. The remaining parts of the AIoT architecture shown in Figure 4.2.2.1-2 remain unchanged.

Copy of original 3GPP image for 3GPP TS 23.369, Fig. 4.2.2.3-2: NG-RAN - AIOT Indirect connectivity Architecture in reference point representation

Figure 4.2.2.3-2: NG-RAN - AIOT Indirect connectivity Architecture in reference point representation
(⇒ copy of original 3GPP image)

4.3 Reference points p. 12

The AIoT Architecture contains the following reference points:

AIOT1:

Reference point between the AIoT Device and the AIOTF.

AIOT2:

Reference point between the NG-RAN and the AIOTF.

The following reference points show the interactions that exist between the NF services in the NFs. These reference points are realized by corresponding NF service-based interfaces and by specifying the identified consumer and producer NF service as well as their interaction in order to realize a particular system procedure.

AIOT3:

Reference point between the AIOTF and the AMF.

AIOT4:

Reference point between the AIOTF and the NEF.

AIOT5:

Reference point between the AIOTF and the NRF.

AIOT6:

Reference point between the AIOTF and the ADM.

AIOT7:

Reference point between the ADM and the UDR.

AIOT8:

Reference point between the ADM and the NEF.

In addition to the relevant reference points defined in TS 23.501, in the case of AIoT, these reference points are as follows:

N2:

Reference point between the NG-RAN and the AMF.

N33:

Reference point between NEF and AF.

4.4 Service-based interfaces p. 12

Naiotf:

Service-based interface exhibited by the AIOTF.

Nadm:

Service-based interface exhibited by the ADM.

In addition to the relevant services defined in TS 23.501 the following service-based interfaces are enhanced for AIoT in this specification:

Namf:

Service-based interface exhibited by AMF.

Nnef:

Service-based interface exhibited by NEF.

Naf:

Service-based interface exhibited by AF.

Nnrf:

Service-based interface exhibited by NRF.

4.5 Functional Entities p. 13

4.5.1 AIoT Device p. 13

4.5.2 NG-RAN p. 13

The NG-RAN in this specification refers to the gNB which supports AIoT related functionalities as specified in clause 4.2.1.

The NG-RAN supports the following functions:

The NG-RAN communicates with the AIOTF either via a direct connectivity or indirectly connectivity.
The NG-RAN serves one or more AIoT readers.
The NG-RAN supports the inventory and command procedures.
The NG-RAN supports the functionalities defined in TS 38.300.
The NG-RAN and AIoT readers may aggregate data collected from multiple AIoT devices in accordance with the assistance information as specified in clause 5.9.

4.5.3 AIOTF p. 13

The AIOTF supports the following functions:

Termination of AIoT NAS protocol with AIoT Device.
Connectivity with an NG-RAN via a direct interface reference point or via an AMF.
Support of AIoT service operations towards the AIoT Devices(s):
- Providing an interface to the AF (or via NEF) for AIoT services and authorizing the trusted AF's AIoT service operation request.
- Triggering the NG-RAN to perform AIoT service operations towards the AIoT Device(s), and optionally determining and providing assistance information to the NG-RAN .
- Report the service operation results to AF (or via NEF) based on the local configuration or the AF request.
- NG-RAN selection and optionally a list of RAN Reader selection for AIoT service operations.
- AMF selection based on target area information when AIOTF connects the NG-RAN indirectly via an AMF.
- Correlation ID allocation corresponding to the AF service operation request.
Retrieving AIoT device profile data from ADM.
Retrieving AF subscription data from ADM.
Optionally AIoT Device context management.
Perform aggregation of the AIoT service responses, determine and provide assistant for the AIoT aggregation in NG-RAN.

4.5.4 NEF p. 14

In addition to the functions defined in TS 23.501, the NEF performs the following functions:

Providing a service exposure API to AFs of 3rd party for AIoT services.
Interacting with AF of 3rd party and AIOTF.
Selection of AIOTF for AIoT services.
Authorization of the untrusted AF's AIoT operation request.

4.5.5 AF p. 14

The AF performs the following functions to support AIoT services:

Interacting with NEF for AIoT related service exposure for 3rd party .
Interacting with AIOTF for AIoT related service exposure for trusted AF.

4.5.6 NRF p. 14

In addition to the functions defined in TS 23.501, the NRF performs the following functions:

Support of new NF type AIOTF and its corresponding NF profile. The NF profile includes the AIOTF ID, FQDN or IP address, NF type and the serving area information of the AIOTF.

NOTE:
The serving area information of the AIOTF is constructed by the sum of the supported AIoT serving area of the NG-RAN nodes that are directly or indirectly connected to the AIOTF.
Support of AIOTF discovery based on parameters Target Area information.
Support of new NF type ADM and its corresponding NF profile. The NF profile includes the ADM ID, FQDN or IP address, NF type, the supported domain information of AIoT device permanent IDs, the supported AIoT device permanent ID ranges, and optionally the supported AF IDs.
Support of ADM discovery based on parameters as specified in clause 5.3.2.

The AIOTF, the ADM register or update its NF profile to NRF by means of the method as defined in clause 4.17.2 of TS 23.502.

4.5.7 AMF p. 14

The AMF performs the following functions when the NG-RAN and the AIOTF communicate indirectly via an AMF:

Relaying signalling for AIoT service (including e.g., inventory/command messages) between NG-RAN and AIOTF transparently.
Providing transparent transport for AIoT NAS messages between AIoT Device and AIOTF.

4.5.8 UDR p. 14

In addition to the functions defined in TS 23.501, the UDR may support the following functions:

Storage of Ambient IoT data, including:
- AIoT device profile data.
- AF authorization data.

4.5.9 ADM p. 14

The ADM supports the following functions:

Management of AIoT device profile data.
Management of AF authorization data.

The AIoT device profile data and AF authorization data used by the ADM may be stored in the UDR.

4.6 Protocol Stacks p. 15

4.6.1 General p. 15

This clause specifies the protocol stacks among entities used for AIoT. The protocol stacks include the following:

Protocol stacks between AIoT Device and AFs, including the protocol stacks among AIoT Device, NG-RAN, AMF, AIOTF, NEF and AFs.

4.6.2 Protocol Stack between AIoT Device and AF p. 15

4.6.2.1 General p. 15

The NG-RAN communicates with AIOTF via one of the two connectivity options as following:

Direct Connectivity: When the NG-RAN communicates with AIOTF directly, the protocol stack is specified in clause 4.6.2.2.
Indirect Connectivity: When the NG-RAN communicates with AIOTF indirectly via an AMF, the protocol stack is specified in clause 4.6.2.3.

For both connectivity options, NG-RAN communicates with AIOTF or AMF via NGAP as specified in TS 38.413.

The AIoT NAS protocol supports the Inventory and Command related procedures as defined in clause 6.

4.6.2.2 Protocol Stack between AF and AIoT Device for NG-RAN Direct Connectivity p. 15

Copy of original 3GPP image for 3GPP TS 23.369, Fig. 4.6.2.2-1: Protocol Stack between AF and AIoT Device for Direct Connectivity option

Figure 4.6.2.2-1: Protocol Stack between AF and AIoT Device for Direct Connectivity option
(⇒ copy of original 3GPP image)

Legend:

AIoT Data: It is the application data exchanged between the AIoT Device and the AF.
AIoT NAS: The NAS protocol between AIoT Device and the AIOTF.
AIoT AS: It is between the AIoT Device and the NG-RAN as specified in TS 38.300.
NGAP: Application Layer Protocol between the AIOTF and the NG-RAN as defined in TS 38.413.
NGAP AIoT Information: It is the subset of NGAP information and is included in the NGAP messages over AIOT2 reference point.

The AIoT NAS messages between the AIoT Device and the AIOTF are transferred via the NG-RAN transparently.

4.6.2.3 Protocol Stack between AF and AIoT Device for NG-RAN Indirect Connectivity p. 16

Copy of original 3GPP image for 3GPP TS 23.369, Fig. 4.6.2.3-1: Protocol Stack between AF and AIoT Device for Indirect Connectivity via AMF option

Figure 4.6.2.3-1: Protocol Stack between AF and AIoT Device for Indirect Connectivity via AMF option
(⇒ copy of original 3GPP image)

Legend:

AIoT Data: It is the application data exchanged between the AIoT Device and the AF.
AIoT NAS: The NAS protocol between AIoT Device and the AIOTF.
AIoT AS: It is between the AIoT Device and the NG-RAN as specified in TS 38.300.
NGAP: Application Layer Protocol between the AMF and the NG-RAN as defined in TS 38.413.
NGAP AIoT Information: It is the subset of NGAP information that the AMF transparently relays between the NG-RAN and the AIOTF, and is included in the NGAP messages and the AIOT3 messages.

In the Indirect Connectivity option, the AMF is involved and its functionality is as defined in clause 4.5.7. The AIoT NAS messages between the AIoT Device and the AIOTF are transferred via the NG-RAN and AMF transparently.