In the context of this specification, an NF service is offering a capability to authorised consumers.
Network Functions may offer different capabilities and thus, different NF services to distinct consumers. Each of the NF services offered by a Network Function shall be self-contained, reusable and use management schemes independently of other NF services offered by the same Network Function (e.g. for scaling, healing, etc).
The discovery of the NF instance and NF service instance is specified in clause 6.3.1
There can be dependencies between NF services within the same Network Function due to sharing some common resources, e.g. context data. This does not preclude that NF services offered by a single Network Function are managed independently of each other.
Each NF service shall be accessible by means of an interface. An interface may consist of one or several operations.
System procedures, as specified in TS 23.502
can be built by invocation of a number of NF services. The following Figure shows an illustrative example on how a procedure can be built; it is not expected that system procedures depict the details of the NF Services within each Network Function.
7.2.2 AMF Services Word-p. 370
The SCP can be used for indirect communication between NF/NF service instances. For simplicity the SCP is not shown in the procedure.
The following clauses provide for each NF the NF services it exposes through its service based interfaces.
The following NF services are specified for AMF:
7.2.3 SMF Services Word-p. 371
Enables an NF consumer to communicate with the UE and/or the AN through the AMF.
This service enables SMF to request EBI allocation to support interworking with EPS. This service also supports PWS functionality as described in TS 23.041
Enables other NF consumers to subscribe or get notified of the mobility related events and statistics.
Enables an NF consumer to make sure UE is reachable.
Enables an NF consumer to request location information for a target UE.
The following NF services are specified for SMF:
7.2.4 PCF Services
This service manages the PDU Sessions and uses the policy and charging rules received from the PCF. The service operations exposed by this NF service allows the consumer NFs to handle the PDU Sessions.
This service exposes the events happening on the PDU Sessions to the consumer NFs.
This service is used for NIDD transfer between SMF and another NF.
The following NF services are specified for PCF:
This PCF service provides Access Control, network selection and Mobility Management related policies, UE Route Selection Policies to the NF consumers.
This PCF service provides session related policies to the NF consumers.
This PCF service authorises an AF request and creates policies as requested by the authorised AF for the PDU Session to which the AF session is bound to. This service allows the NF consumer to subscribe/unsubscribe to the notification of Access Type and RAT type, PLMN identifier, access network information, usage report etc.
This PCF service provides background data transfer policy negotiation and optionally notification for the renegotiation to the NF consumers.
This PCF service provides the management of UE Policy Association to the NF consumers.
This PCF service provide the support for event exposure.
7.2.5 UDM Services Word-p. 372
The following NF services are specified for UDM:
1. Provide the NF consumer of the information related to UE's transaction information, e.g. UE's serving NF identifier, UE status, etc.
2. Allow the NF consumer to register and deregister its information for the serving UE in the UDM.
3. Allow the NF consumer to update some UE context information in the UDM.
1. Allow NF consumer to retrieve user subscription data when necessary.
2. Provide updated user subscriber data to the subscribed NF consumer.
1. Provide updated authentication related subscriber data to the subscribed NF consumer.
2. For AKA based authentication, this operation can be also used to recover from security context synchronization failure situations.
3. Used for being informed about the result of an authentication procedure with a UE.
1. Allow NF consumer to subscribe to receive an event.
2. Provide monitoring indication of the event to the subscribed NF consumer.
1. To provision information which can be used for the UE in 5GS.
1. To authorise an NIDD configuration request for the received External Group Identifier or GPSI.
7.2.6 NRF Services Word-p. 373
The following NF services are specified for NRF:
7.2.7 AUSF Services
Provides support for register, deregister and update service to NF, NF services. Provide consumers and SCP with notifications of newly registered/updated/deregistered NF along with its NF services.
Enables one NF service consumer or SCP to discover a set of NF instances with specific NF service or a target NF type. Also enables one NF service or SCP to discover a specific NF service.
Provides OAuth2 2.0 Access Tokens for NF to NF authorization as defined in TS 33.501
The following NF services are specified for AUSF:
7.2.8 NEF Services Word-p. 374
The AUSF provides UE authentication service to requester NF. For AKA based authentication, this operation can also be used to recover from security context synchronization failure situations.
The AUSF provides protection of Steering of Roaming information service to the requester NF.
The AUSF provides NSSAA service to the requester NF by relaying EAP messages towards a AAA-S or AAA-P and performing related protocol conversion as needed. It also provides notification to the current AMF where the UE is of the need to re-authenticate and re-authorize the UE or to revoke the UE authorization.
The following NF services are specified for NEF:
Provides support for event exposure.
Provides support for PFDs management.
Provides support to provision information which can be used for the UE in 5GS.
Provides support for device triggering.
Provides support for background data transfer policy negotiation and optionally notification for the renegotiation.
Provide the ability to influence traffic routing.
Requests to become the chargeable party for a data session for a UE.
Requests the network to provide a specific QoS for an AS session.
Used by the NEF to send MSISDN-less MO SM to the AF.
Provides support to provision service specific information.
Provides support for awareness on availability or expected level of a service API.
Used for configuring necessary information for data delivery via the NIDD API.
Used for NEF anchored MO and MT unstructured data transport.
Provides the capability to create, update or release the SMF-NEF Connection.
Provides support for exposure of network analytics.
Provides the ability to configure the UCMF with dictionary entries consisting of UE manufacturer-assigned UE Radio Capability IDs, the corresponding UE radio capability and the (list of) associated IMEI/TAC value(s) via the NEF. Also used for deletion (e.g. as no longer used) or update (e.g. to add or remove a (list of) IMEI/TAC value(s) associated to an entry) of dictionary entries in the UCMF.
Provides support for queuing status of enhanced coverage restriction, or enable/disable enhanced coverage restriction per individual UEs.
Provides the capability to apply a previously negotiated Background Data Transfer Policy to a UE or a group of UEs.
Provides the capability to deliver UE location to AF.
7.2.8A I-NEF Services [R16] Word-p. 375
The following NF services are specified for I-NEF:
7.2.9 SMSF Services Word-p. 376
Provides support for event exposure.
The following NF services are specified for SMSF:
7.2.10 UDR Services
This service allows AMF to authorize SMS and activate SMS for the served user on SMSF.
The following NF services are specified for UDR:
7.2.11 5G-EIR Services
Allows NF consumers to retrieve, create, update, subscribe for change notifications, unsubscribe for change notifications and delete data stored in the UDR, based on the set of data applicable to the consumer.
This service may also be used to manage operator specific data.
Allows NF consumers to retrieve a NF group ID corresponding to a subscriber identifier.
The following NF services are specified for 5G-EIR:
7.2.12 NWDAF Services
N5g-eir_Equipment Identity Check
This service enables the 5G-EIR to check the PEI and check whether the PEI is in the black list or not.
The following NF services are specified for NWDAF:
7.2.13 UDSF Services Word-p. 377
This service enables the NF service consumers to subscribe/unsubscribe for different type of analytics from NWDAF.
This service enables the NF service consumers to request and get different type of analytics information from NWDAF.
The following NF services are specified for UDSF:
7.2.14 NSSF Services
Allows NF consumers to retrieve, create, update, and delete data stored in the UDSF.
The following NF services are specified for NSSF:
7.2.15 BSF Services
Provides the requested Network Slice information to the Requester.
Provides NF consumer on the availability of S-NSSAIs on a per TA basis.
The following NF services are specified for BSF as described in TS 23.503
7.2.16 LMF Services
Allows a PCF to register/deregister itself and to be discoverable by NF service consumers.
The following NF services are specified for LMF:
7.2.16A GMLC Services [R16]
This service enables an NF to request location determination for a target UE for the Immediate Location Request and to subscribe / get notified of the location determination for a Deferred Location Request. It allow NFs to request or subscribe the current geodetic and optionally civic location of a target UE.
The following NF services are specified for GMLC:
7.2.17 CHF Services Word-p. 378
This service enables an NF to request location determination for a target UE.
The following NF services are specified for CHF.
7.2.18 UCMF Services [R16]
This service enables transfer of policy counter status information relating to subscriber spending limits from CHF to NF consumer
This service is described for offline only charging as described in TS 32.290
The following NF services are specified for UCMF:
Allows the NF consumer to provision a dictionary entry in the UCMF consisting of a Manufacturer-assigned UE Radio Capability ID and the corresponding UE radio capabilities and the (list of) associated IMEI/TAC value(s). Also used for deletion (e.g. as no longer used) or update (e.g. to add or remove a (list of) IMEI/TAC value(s) associated to an entry) of dictionary entries in the UCMF.
Allows the NF consumer to resolve UE Radio Capability ID (either Manufacturer-assigned or PLMN-assigned) into the corresponding UE radio capabilities.
Allows the NF consumer to obtain a PLMN-assigned UE Radio Capability ID for a specific UE radio capabilities.
Allows the NF consumer to subscribe or unsubscribe for notifications of UCMF dictionary entries.
Allows the NF consumer to be notified about creation and deletion of UCMF dictionary entries.
7.2.19 AF Services [R16]
The following NF services are specified for AF:
This service enables consumer NF(s) to subscribe or get notified of the event as described in TS 23.288
Network exposure is described in clause 5.20
and in TS 23.502, clause 4.15