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fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.15.11 Void | |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.15.12 UPF Event Exposure Direct Reporting | |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.15.12.1 General | UPF may expose information directly via a service based interface by means of the UPF Event Exposure service described in clause 5.2.26.2 and as described in clause 5.6.17 of TS 23.501 [2].
Exposure of QoS Monitoring via direct interaction between UPF and Local NEF/AF is described in clause 4.15.12.2 and Notification of Handling of Payload Headers events in clause 4.15.12.3.
UPF event exposure direct reporting as part of UPF data collection procedures is described in clause 4.15.4.5. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.15.12.2 QoS monitoring exposure | This clause contains the description and the procedure for the exposure of QoS monitoring information via direct interaction between UPF (L-PSA UPF) and Local NEF/AF.
Editor's note: It is FFS whether Local NEF is introduced or NEF is used instead.
Figure 4.15.12-1: Event exposure using Local NEF
1. The UPF obtains QoS monitoring information as defined in clauses 5.8.2.18 and 5.45 of TS 23.501 [2].
2. The UPF sends the notification related with QoS monitoring information over Nupf_EventExposure_Notify service operation according to the configuration from SMF as defined in clause 5.8.2.18 of TS 23.501 [2]. The notification is sent to the Notification Target Address that may correspond (4a) to the AF or (4b) to the Local NEF.
3. If the Local NEF is used, it reports the QoS monitoring information to the AF by invoking Nnef_EventExposure_Notify service operation. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.15.12.3 Notification of Handling of Payload Header Events | When AF subscribes to UPF event for Handling of Payload Headers, it provides reporting control information (i.e. Header Handling Reporting Endpoints, etc) as described in clause 5.6.17 of TS 23.501 [2] and PCF includes it in the PCC Rule.
When SMF receives a PCC Rule with Header Handling Control information, if it is including reporting control information for Handling of Payload Header Events, SMF includes it in the instructions to UPF as described in clause 5.8.5.6 of TS 23.501 [2]. The SMF may also decide based on local configuration to subscribe itself to notifications of Handling of Payload Header event and if so, it provides the Header Handling Reporting Endpoint information and Header Handling Reporting for the actions it is interested in. For more information see clause 5.6.17 of TS 23.501 [2].
When a notification reporting trigger is met, UPF notifies the performed action events to the notification endpoint(s) (i.e. AF/NEF and/or SMF) using Nupf_EventExposure_Notify service operation according to the instructions received from SMF (see clause 5.8.2.22 of TS 23.501 [2]). Figure 4.15.12.3-1 shows the notification procedure.
Figure 4.15.12.3-1: Notification of Handling of Payload Header Event
In this procedure, UPF has received instructions for Handling of Payload Headers including reporting control information as described in clause 5.8.5.6 of TS 23.501 [2]. At some moment in time:
1. The conditions for notification of Handling of Payload Headers event is met.
2. UPF sends notification(s) to the notification endpoint(s) received in the instructions from SMF by means of Nupf_EventExposure_Notify:
2a. to SMF, if SMF has subscribed to Handling of Payload Headers and it has included its own Notification Target address;
2b. to AF, if AF has subscribed to Handling of Payload Headers event and the Notification Target address that UPF receives is the AF;
2c. to NEF, if AF has subscribed to Handling of Payload Headers event and the Notification Target address that UPF receives is the NEF.
NOTE: Trusted AFs receive notifications directly from UPF. If AF is untrusted, it receives the notifications via NEF.
3. If NEF receives a Nupf_EventExposure_Notify from UPF (step 2c), it notifies to AF by means of Nnef_TrafficInfluence_Notify. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.15.13 Assistance for Member UE selection | |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.15.13.0 General | Assistance for Member UE selection allows the AF to request the 5GC to filter a list of AF provided target member UEs according to AF provided criteria (Member UE filtering criteria) and to provide one or more list(s) of candidate UEs (and additional information) as response to the AF.
With the initial subscription request, the AF provides a list of target member UEs in the form of a list of GPSIs or a list of UE IP addresses and at least one Member UE filtering criterion as part of the service operation input parameters to assist the candidate UEs selection. Upon receiving the AF request, NEF triggers corresponding 5GC procedures to retrieve from 5GC NFs the information for the UEs in the list of target member UEs. Before sending the list(s) of candidate UEs to the AF, NEF consolidates all the information collected from other 5GC NFs and derives one or more list(s) of candidate UEs and possibly additional information according to the Member UE filtering criteria provided by the AF. The NEF finally provides the one or more list(s) of candidate UEs and possibly additional information to the AF together with a Subscription Correlation ID.
AF may subsequently update the parameters for the Member UE filtering criteria, the Member UE filtering criteria, or the Member UE filtering criteria values. In all cases, AF includes the Subscription Correlation ID in the request, but does not include the list of target member UEs. AF may request to update the parameters (e.g. expiry time, time window for selecting the candidate UEs) for the subscribed Member UE filtering criteria. AF may also request to update the Member UE filtering criteria by adding new Member UE filtering criteria or removing part of the subscribed Member UE filtering criteria. The AF may also request to update the Member UE filtering criteria values.
The Member UE selection assistance capability can be used to assist the AF to select the list of member UEs to support application service (e.g. FL operation) as described in clause 5.46.2 of TS 23.501 [2].
Additionally, AF may leverage the 5GC network exposure for Member UE selection without the NEF assistance as described in clause 5.46.2 of TS 23.501 [2]. An example of how the AF leverages the 5GC network exposure for Member UE selection is described in (informative) Annex I.
AF may also delete the previous subscription for Member UE selection assistance as described in clause 4.15.13.7. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.15.13.1 Member UE selection assistance subscribe and update procedure | This clause describes the Member UE selection assistance subscribe and update procedure that is generally applicable independently of the Member UE filtering criteria sent by the AF.
Figure 4.15.13.1-1: Member UE selection assistance subscribe and update procedure
1. AF subscribes the Member UE selection assistance by sending a Nnef_MemberUESelectionAssistance_subscribe request including a list of target member UEs, one or more member UE filtering criteria as listed in Table 4.15.13.2-1 and optionally, time window(s). Subsequently, the AF may only update the Member UE filtering criteria of the subscription as described in clause 4.15.13.0 by invoking Nnef_MemberUESelectionAssistance_subscribe and providing a Subscription Correlation ID, i.e. the AF does not provide the list of target member UEs again.
NOTE: The time window(s) for selecting the candidate UE(s) is used by the NEF when subscribing/requesting to NWDAF. The NEF maps the time window(s) for selecting the candidate UE(s) to the Analytics target period, which should be included in the Nnwdaf_AnalyticsSubscription_Subscribe or Nnwdaf_AnalyticsInfo_Request service operations.
2a. [CONDITIONAL] If the AF request does not contain a Subscription Correlation ID, the NEF verifies the authorization of the AF request and identifies which information needs to be collected for each UE in the list of target member UEs and executes the corresponding service operations based on the Member UE filtering criteria provided by the AF, e.g. events, analytics ID(s), notifications, etc.
2b. [CONDITIONAL] If the AF request contains a Subscription Correlation ID, the NEF correlates the Nnef_MemberUESelectionAssistance_Subscribe request to an existing subscription according to the Subscription Correlation ID. The NEF updates the Member UE filtering criteria and/or their parameters (as described in clause 4.15.13.0) for the list of target member UEs received in initial subscription (i.e. no Subscription Correlation ID in the subscription request).
3. NEF interacts with different 5GC network functions to collect the required information for each UE in the list of target member UEs. The set of interactions between the NEF and the 5GC NFs depend on the Member UE filtering criteria provided by the AF. See Table 4.15.13.2-1 for details.
4. Based on the collected information from other 5GC NFs, the NEF consolidates all the information to derive the list(s) of candidate UEs which fulfil the Member UE filtering criteria in the AF request. The NEF may derive recommended time window(s), considering the validity period(s) of the analytics used for Member UE selection criteria. The recommended time window(s) may be a subset of the time window(s) received from the AF. In different recommended time windows, the list of candidate UEs which fulfil the Member UE filtering criteria may be different.
5. NEF sends a Nnef_MemberUESelectionAssistance_Notify request to the AF including the list(s) of candidate UEs and possibly additional information. See clause 5.2.6.32.4 for details. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.15.13.2 Member UE Filtering Criteria for 5GS assistance to Member UE selection | Table 4.15.13.2-1 provides a summary of the Member UE filtering criteria that the AF may request.
Table 4.15.13.2-1: Description of Member UE filtering criteria
Member UE filtering criteria
Description of filtering criteria for member UEs selected by NEF
UE filtering information
Detailed description clause
QoS
The Quality of Service of the member UEs match or exceed the QoS of the filtering criteria.
NF service: Nsmf_EventExposure or Nudm_EvenExposure,
Filter: target=SUPI, traffic descriptor (e.g. Application ID), DNN/S-NSSAI
Event ID: QoS Monitoring
4.15.13.3
Access Type and/or RAT Type of the PDU Session
Indicate the Access Type and/or RAT Type of the member UEs for the PDU Session used by the application (e.g. 3GPP/NR, Non-3GPP/WLAN, additional Access Type and RAT Type for MA PDU session).
NF service: Nsmf_EventExposure
Filter: a list of GPSI(s) or SUPI(s), DNN/S-NSSAI, Event ID: Change of Access Type and/or Change of RAT Type
5.2.8.3
End-to-end data volume transfer time
Indicate the target end-to-end data volume transfer time that refers to a time for completing the transmission of a specific data volume between UE and AF, e.g. the average and variance of End-to-end data volume transfer time.
NF service: Nnwdaf_AnalyticsSubscription/ Nnwdaf_AnalyticsInfo
Filter: Target = GPSI(s) or SUPI(s)
Analytics ID: E2E data volume transfer time
4.15.13.6
UE current location
Indicate the certain area that the member UEs are currently located in.
NF service: Namf_EventExposure
Filter: a list of GPSI(s) or SUPI(s)
Event ID: Location Report
4.15.13.4
UE historical location
Indicate the certain area that the member UEs appeared in a historical period of time.
NF service:
Nnwdaf_AnalyticsSubscription / Nnwdaf_AnalyticsInfo
Filter: Visited AoI = Target AOI, target period = historical nomadic period
Analytics ID = UE mobility
4.15.13.4
UE direction
Indicate the member UEs should include different moving directions.
NF service:
Nnwdaf_AnalyticsSubscription / Nnwdaf_AnalyticsInfo
Filter: UE Direction
Analytics ID= UE Mobility
4.15.13.4
UE separation distance
(NOTE 1)
Indicate the member UEs should comply with a minimum separation distance between each other.
NF service:
Nnwdaf_AnalyticsSubscription/
Nnwdaf_AnalyticsInfo
Filter: Proximity Attributes
Analytics ID: Relative Proximity
4.15.13.4
Service Experience
Indicates member UEs fulfilling certain Service Experience criteria e.g. MOS value.
NF service: Nnwdaf_AnalyticsSubscription/ Nnwdaf_AnalyticsInfo
Filter: S-NSSAI, DNN, Application ID, DNAI, AoI, Service Experience Contribution weight, reporting threshold (NOTE 2), Service Experience Type (NOTE 3)
Analytics ID=Service Experience
4.15.13.5
DNN
Indicate the DNN of the member UEs for the PDU Session used by the application.
NF service: Nsmf_EventExposure
Filter: a list of GPSI(s) or SUPI(s), Event ID: QFI allocation
5.2.8.3
NOTE 1: This criterion should only be applied when the number of UEs is in the range of 10's or less.
NOTE 2: The Service Experience Contribution Weights signal the relative importance of each UE's Service Experience value (i.e. MOS), as defined in TS 23.288 [50]. For example, it might be that the service experience of a UE in relation to other UEs may not be as important e.g. because the data provided by such UE is not as critical to the service.
NOTE 3: Indicates the type of service experience analytics, e.g. AI/ML traffic where a customized MoS apply. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.15.13.3 Specific procedure for QoS Member UE filtering criteria | |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.15.13.3.1 General | An AF may invoke Nnef_MemberUESelectionAssistance_Subscribe service operation with one QoS filtering criterion for receiving a list of UEs that match or exceed such criteria.
In addition to the mandatory parameters, the AF also includes in the request:
- QoS filtering criteria.
- Optionally, an Area of Interest: location area of the candidate UEs.
The QoS filtering criteria includes:
- a traffic descriptor (e.g. Application ID).
- Optionally, DNN.
- Optionally, S-NSSAI.
And one or more of the QoS parameters subject to QoS monitoring (see list in clause 5.45 of TS 23.501 [2]).
The determination of the list of UEs that match or exceed the QoS filtering criteria and are optionally located in the AoI in real time, for the duration of the subscription, is further described in clause 4.15.13.3.3. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.15.13.3.2 Void | |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.15.13.3.3 Member UE Selection Assistance with QoS filtering criteria for real-time QoS Monitoring | At the reception of Nnef_MemberUESelectionAsistance_Subscribe request of step 1, in order to detect the list of UEs that fulfil the QoS filtering criteria in real time, NEF performs real-time QoS monitoring. Unless the QoS flow to be monitored is associated with a default QoS flow, QoS Monitoring needs to be activated in SMF for that QoS Flow before (e.g. by AF Session with required QoS) (see clause 4.15.4.5.1 for details).
Figure 4.15.13.3.3-1: 5GC assistance to Member UE selection for real-time QoS monitoring
1. AF subscribes to the Member UE selection assistance functionality by sending Nnef_MemberUESelectionAssistance_subscribe request including its AF ID, a list of target UE(s) and the QoS filtering criteria.
2. NEF uses the AF ID to verify the authorization of the AF request and identifies which information needs to be collected based on the QoS filtering criteria provided by the AF.
3. If S-NSSAI/DNN are not included in the request from the AF, the NEF derives the S-NSSAI and DNN which this Application has access to. NEF discovers the SMFs that are deployed in the Area of Interest by querying UDM and NRF. The NEF may also restrict the discovery to those SMFs that serve some S-NSSAI and DNN combination.
4. For each target SMF, NEF sends an Nsmf_EventExposure_Subscribe request (Event: 'QoS monitoring', target member UEs, optionally a traffic descriptor (e.g. Application ID), optionally indication for default QoS flows monitoring, S-NSSAI, DNN, Notification Target Address set to NEF, etc.). Alternatively, NEF may send an Nudm_EventExposure_Subscribe request to the UDM (not shown in Figure 4.15.13.3.3-1).
5. The SMF may need to send an N4 Session Modification request to UPF for requesting the QoS monitoring for certain flows.
6. UPF sends an Nupf_EventExposure_Notify request to NEF including an Event Exposure notification, according to the subscription received from SMF.
7. Based on the Event Exposure reports received from the UPFs, NEF consolidates the received results and derives the list(s) of candidate UE(s) and additional information which fulfil the QoS filtering criteria provided by the AF.
8. NEF sends a Nnef_MemberUESelectionAssistance_Notify request to the AF including the list(s) of candidate UE(s) and additional information. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.15.13.4 Specific procedure for the 5GC assistance to member UE selection based on the UE's current location, historical location and direction and UE separation distance | Figure 4.15.13.4-1: 5GC assistance to Member UE selection based on the UE's current and historical location, direction and separation distance
1. AF requests 5GS assistance to support the Member UE selection by considering the UE's historical location, UE's current location, direction and UE separation distance. AF includes the UE lists and the following criteria as part of the member UE selection request:
- UE historical location: The Target AoI where the UEs have been roving over the historical nomadic period before moving into the FL coverage area.
- UE current location: The current AoI which is the coverage area of the FL training server where the selected UEs located in to participate in the FL operation.
- UE Direction: Select the UE with the different direction in the FL coverage Area.
- UE separation distance: Select UEs that are geographically separated, fulfilling the separation distance no smaller than the certain predefined separation distance.
When providing a target area for e.g. FL operation, the AF may provide sub-areas, and provide a maximum number of UEs that should take part in FL from each sub-area.
2. NEF translates the GPSIs to SUPIs and maps the filtering criteria into the corresponding UE filtering information.
3-4. The NEF invokes Namf_EventExposure_Subscribe service operation with the UE list, the current AoI and event ID = Location report. AMF will provide a list of UEs that are within the current AoI to the NEF using the Namf_EventExposure_Notify service operation. The NEF obtains the list of possible member UEs from AMF within the current AoI.
5. In order to identify the appropriate NWDAF which can provide analytics output to derive the visited AOI info and get the UE direction for the possible target member UEs above, the NEF initiates NWDAF discovery request (Analytics ID = UE mobility/Relative Proximity, AOI = Target AOI) with UE list received from step 4.
6-7. The NEF invokes NWDAF Analytics Info request (UE list received from step 4, Analytics ID = UE mobility, Relative Proximity, Filters include "Visited AoI = Target AOI", "target period = historical nomadic period" and "proximity attributes"). In a response, NWDAF provides a list of UEs that were ever roving within the target AOI, at the minimum, over the historical nomadic period. Additionally, NWDAF provides a list of UEs location in the order of which the UE passes through. Thus, the NEF gets the corresponding statistics of UE mobility, the UE's direction and distance between UEs in the group/list.
8-9. Based on the information provided by the AMF and NWDAF, the NEF can determine the FL candidate UEs which are now within the FL coverage area but were roving within the target AOI over the historical nomadic period and UE with the different direction and separated from each other fulfilling the minimum distance threshold as requested by AF. The NEF notifies AF for such UE candidate list.
10. The NEF also needs to consider the list of UEs which are now within the FL coverage area, but may move out of the FL coverage area. Therefore, for each UE in the candidate list in steps 8-9, the NEF invokes the Namf_EventExposure_Notify service with UE ID = SUPI, Event ID=UE moving in/out of AOI in order to keep tracking the movement of the UE(s).
11-12. If step 10 identifies any UE which is moving out of the FL coverage area, the NEF may update the candidate UEs and notify to the AF. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.15.13.5 Specific procedure for Service Experience Member UE filtering criteria | |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.15.13.5.1 General | An AF may invoke Nnef_MemberUESelectionAssistance_Subscribe service operation with a Service Experience filtering criteria for receiving a list of UEs that fulfil such criteria.
In addition to the mandatory parameters, the AF may also include in the request:
- Service Experience filtering criteria.
- An Area of Interest: location area of the candidate UEs.
- Time windows for selecting the candidate UEs: start time and stop time.
- Service Experience contribution weights.
- Service Experience Type.
The AF may provide a Service Experience filtering criteria, including contribution weights associated to location, e.g. AoI or DNAI, time window, Application ID and Service Experience type e.g. contribution weight may be provided to favour Service Experience type relative to AIML traffic in a particular location. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.15.13.5.2 Member UE Selection Assistance with Service Experience filtering criteria | Figure 4.15.13.5.2-1: 5GC assistance to Member UE selection based on Service Experience
1. AF subscribes to the Member UE selection assistance functionality by sending Nnef_MemberUESelectionAssistance_subscribe request including the Application Identity, AoI, DNN/S-NSSAI, DNAI(s), Service Experience Type and contribution weights associated to location, time window, Application ID and Service Experience type.
2. NEF verifies the authorization of the AF Request and identifies which information needs to be collected and executed based on the Service Experience filtering criteria provided by the AF.
3. If S-NSSAI/DNN and DNAI(s) are not included in the request from the AF, the NEF derives the S-NSSAI, DNN and DNAI(s) which this Application has access to. NEF discovers and selects the NWDAF(s) by invoking Nudm_UECM_Get or Nnrf_NFDiscovery_Request including Analytics ID = Service Experience, AoI, S-NSSAI, etc.
4. NEF sends an Analytics request/subscribe to NWDAF by invoking a Nnwdaf_AnalyticsInfo_Request or a Nnwdaf_AnalyticsSubscription_Subscribe, including Analytics ID = Service Experience, Application ID, S-NSSAI, DNN, AoI, DNAI(s), and target UEs based on the initial list obtained from the AF.
5-7. Procedures as specified in clause 6.4.6 of TS 23.288 [50] are followed.
8. The NWDAF provides the data analytics, i.e. the observed Service Experience (which can be a range of values) to the consumer NF by means of either Nnwdaf_AnalyticsInfo_Request response or Nnwdaf_AnalyticsSubscription_Notify, depending on the service used in step 4.
9. Based on the Analytics report received from the NWDAF, NEF consolidates results and derives the list(s) of candidate UE(s). For applying that, NEF may use the Service Experience type provided by the AF consumer in the filtering information and use operator policies to interpret a customized MoS. Additionally, NEF may use the contribution weight associated to an application and a Service Experience Type (e.g. AI/ML traffic) and apply them to a location and time window, as provided by the AF consumer, to be used as reporting thresholds when selecting candidate Member UEs, e.g. the NEF may select a UE with a specific Service Experience Type as a Member UE candidate, if the associated Service Experience fulfils the threshold for Service Experience filtering criteria provided by the AF.
10. NEF sends a Nnef_MemberUESelectionAssistance_Notify request to the AF including the list(s) of candidate UE(s) and additional information. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.15.13.6 Specific procedure for end-to-end data volume transfer time related member UE filtering criteria | |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.15.13.6.1 General | An AF may invoke Nnef_MemberUESelectionAssistance_Subscribe service operation with end-to-end data volume transfer time related filtering criteria for receiving a list of UEs that fulfil the filtering criteria.
In addition to the mandatory parameters, the AF may also include in the request:
- End-to-end data volume transfer time filtering criteria: this may include the average end-to-end data volume transfer time for a specific data volume between UE and AF and/or the variance of the end-to-end data volume transfer time.
- An Area of Interest: location area of the candidate UEs.
- Time windows for selecting the candidate UEs: start time and stop time.
- Data Volume UL/DL: the expected or observed data volume from UE to AF or from AF to UE which may be used to derive the end-to-end data volume transfer time analytics.
- The target number of data transmission repetitions or target time interval between data transmissions.
- A request for geographical distribution of UEs. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.15.13.6.2 Member UE Selection assistance with end-to-end data volume transfer time related filtering criteria | Figure 4.15.13.6.2-1: Assistance to member UE selection for end-to-end data volume transfer time related filtering criteria
1. AF subscribes to the member UE selection assistance functionality by invoking Nnef_MemberUESelectionAssistance_subscribe request including the Application ID, DNN/S NSSAI, AoI, and the end-to-end data volume transfer time related filtering criteria including the average end-to-end data volume transfer time and/or the variance of the transfer time, the Data Volume UL/DL, the target number of data transmission repetitions or target time interval between data transmissions, request for geographical distribution (i.e. the AoIs) of the UEs.
2. NEF verifies the authorization of the AF Request and identifies which information needs to be collected and executed based on the end-to-end data volume transfer time related filtering criteria provided by the AF.
3. S-NSSAI/DNN are not included in the request from the AF, the NEF derives the S-NSSAI and DNN which this Application has access to. NEF discovers and selects the NWDAF(s) by invoking Nudm_UECM_Get or Nnrf_NFDiscovery_Request including Analytics ID = E2E data volume transfer time, AoI, S-NSSAI, etc.
4. NEF sends an Analytics request/subscribe to NWDAF by invoking Nnwdaf_AnalyticsSubscription_Subscribe / Nnwdaf_AnalyticsInfo_Request including Analytics ID = E2E data volume transfer time, Application ID, DNN, S-NSSAI, AoI, and target UEs based on the initial UE list obtained from the AF, the target number of data transmission repetitions or target time interval between data transmissions, the Data Volume UL/DL, request for geographical distribution (i.e. the AoIs) of the UEs, etc.
5. The NWDAF collects data from multiple sources for end-to-end data volume transfer time analytics as specified in clause 6.18.2 of TS 23.288 [50].
6. The NWDAF provides the required output analytics to the consumer NF as specified in clause 6.18.4 of TS 23.288 [50] by means of either Nnwdaf_AnalyticsInfo_Request response or Nnwdaf_AnalyticsSubscription_Notify, depending on the service used in step 4.
7. Based on the analytics received from the NWDAF, the NEF consolidates results and derives the list(s) of candidate UE(s) that fulfil the filtering criteria requested by the AF. The NEF may use the average and/or the variance of end-to-end data volume transfer time of specific volumes of UL/DL data indicated by the AF to derive the list(s) of candidate UEs that meet the requirements from the AF.
8. NEF sends a Nnef_MemberUESelectionAssistance_Notify request to the AF including the list(s) of candidate UE(s) and additional information. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.15.13.7 Member UE selection assistance unsubscribe procedure | This clause describes the procedure to delete the subscription for Member UE selection assistance in NEF.
Figure 4.15.13.7-1: Member UE selection assistance unsubscribe procedure
1. AF requests to delete the previous subscription for Member UE selection assistance by sending Nnef_MemberUESelectionAssistance_unsubscribe request including the Subscription Correlation ID.
2. NEF interacts with different 5GC network functions to delete the subscription(s) generated for each UE in the list of target member UEs. The set of interactions between NEF and 5GC NFs are dependent on the Member UE filtering criteria that AF had provided in clause 4.15.13.1.
3. NEF sends a Nnef_MemberUESelectionAssistance_unsubscribe response to the AF with the operation execution result indication. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.16 Procedures and flows for Policy Framework | |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.16.1 AM Policy Association Establishment | |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.16.1.1 General | There are three cases considered for AM Policy Association Establishment:
1. UE initial registration with the network.
2. The AMF re-allocation with PCF change in handover procedure and registration procedure.
3. EPS to 5GS mobility when there is no existing AM Policy Association between AMF and PCF for this UE. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.16.1.2 AM Policy Association Establishment with new Selected PCF | Figure 4.16.1.2-1: AM Policy Association Establishment with new Selected PCF
This procedure concerns both roaming and non-roaming scenarios.
In the non-roaming case the role of the V-PCF is performed by the PCF. For the roaming scenarios, the V-PCF interacts with the AMF.
1. Based on local policies or the value of the AM Policy Association indicator received from UDM, the AMF decides to establish AM Policy Association with the (V-)PCF as defined in clause 6.1.2.1.2 of TS 23.503 [20], then steps 2 to 3 are performed under the conditions described below.
2. [Conditional] If the AMF has not yet obtained access and mobility related policy information for the UE or if the access and mobility related policy information in the AMF is no longer valid, the AMF requests the PCF to apply operator policies for the UE from the PCF. The AMF sends Npcf_AMPolicyControl_Create to the (V-)PCF to establish an AM Policy Association with the (V-)PCF. The request includes the following information: SUPI, Internal Group (see clause 5.9.7 of TS 23.501 [2]), subscription notification indication and if available, Service Area Restrictions, RFSP index, Subscribed UE-AMBR, List of Subscribed UE-Slice-MBR, the Allowed NSSAI, Partially Allowed NSSAI, S-NSSAI(s) rejected partially in the RA, Rejected S-NSSAI(s) for the RA, Pending NSSAI, Target NSSAI (see clause 5.3.4.3.3 of TS 23.501 [2]), Network Slice Replacement supported for the UE (see clause 5.15.19 of TS 23.501 [2]), GPSI, Energy Saving indicator (see clause 5.51.6 of TS 23.501 [2]), which are retrieved from the UDM during the update location procedure and may include Access Type and RAT Type, PEI, ULI, UE time zone and Serving Network (PLMN ID, or PLMN ID and NID, see clause 5.34 of TS 23.501 [2]).
When AMF utilizes an NWDAF, it may add the NWDAF serving the UE identified by the NWDAF instance ID. Per NWDAF service instance the Analytics ID(s) are also included.
3. The PCF may invoke the Nudr_DM_Query service to the UDR. And the UDR may response with the requested policy control subscription data as in clause 6.2.1.3 of TS 23.503 [20] and/or application data as in clause 6.2.1.6 of TS 23.503 [20].
In non-roaming case, if the PCF determines that the policy decision depends on the status of the policy counters available at the CHF and such reporting is not established for the subscriber, the PCF initiates an Initial Spending Limit Report Retrieval as defined in clause 4.16.8.2. If policy counter status reporting is already established for the subscriber and the PCF determines that the status of additional policy counters is required, the PCF initiates an Intermediate Spending Limit Report Retrieval as defined in clause 4.16.8.3.
NOTE 1: The Nudr_DM_Query may include the Spending Limit Information, i.e. the policy counters and their latest status. Thus the PCF can provide the AM policy to the AMF before contacting the CHF. The PCF may need to update the AMF depending on the statuses of the policy counters provided by the CHF.
NOTE 2: Potential inconsistencies between the policy counter and its status in the UDR and in the CHF can happen given that the CHF may update the policy counter and its status at any time, as such it is recommended that the PCF contacts the CHF if the policy counters and its status stored in the UDR is used, to be able to receive updated information from the CHF.
In non-roaming case, the PCF may request notifications from the UDR on changes in the subscription information by invoking Nudr_DM_Subscribe service operation, Data Set "Policy Data" and Data Subset "Access and Mobility policy control data" as defined in clause 6.2.1.3 of TS 23.503 [20] and/or Data set "application data" and Data Subset "AM influence information" as defined in clause 6.2.1.6 of TS 23.503 [20].
The (V)-PCF responds to the Npcf_AMPolicyControl_Create service operation. The (V)-PCF provides access and mobility related policy information (e.g. Service Area Restrictions) as defined in clause 6.5 of TS 23.503 [20]. In addition, (V)-PCF can provide Policy Control Request Trigger of AM Policy Association to AMF. In the non-roaming case, the PCF may subscribe to Analytics from NWDAF as defined in clause 6.1.1.3 of TS 23.503 [20].
The AMF is implicitly subscribed in the (V-)PCF to be notified of changes in the policies.
The (V-)PCF may register to the BSF as the PCF that handles the AM Policy Association for this UE. This is performed by using the Nbsf_Management_Register operation, providing as inputs the UE SUPI/GPSI and the PCF identity.
4. [Conditional] The AMF deploys the access and mobility related policy information which includes storing the Service Area Restrictions and Policy Control Request Trigger(s) of the AM Policy Association, provisioning Service Area Restrictions to the UE and provisioning the RFSP index, the UE-AMBR, List of UE-Slice-MBR, Service Area Restrictions to the NG-RAN as defined in TS 23.501 [2] and request for notification of SM Policy association establishment and termination to a list of (DNN, S-NSSAI)(s) together with PCF for the UE binding information. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.16.1.3 Void | |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.16.2 AM Policy Association Modification | |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.16.2.0 General | There are three cases considered for AM Policy Association Modification:
- Case A: A Policy Control Request Trigger condition is met: the procedure is initiated by the AMF.
- Case B: PCF policy decision per local decision or per trigger by other peers of the PCF (i.e. UDR, AF or NWDAF): the procedure is initiated by the PCF.
- Case C: AM Policy Association Modification with the old PCF during AMF relocation: the procedure is initiated by the AMF.
In the non-roaming case, the PCF may interact with the CHF to make policy decisions, for Access and Mobility related policies, based on spending limits. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.16.2.1 AM Policy Association Modification initiated by the AMF | |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.16.2.1.1 AM Policy Association Modification initiated by the AMF without AMF relocation | This procedure is applicable to Case A.
Figure 4.16.2.1.1-1: AM Policy Association Modification initiated by the AMF
This procedure concerns both roaming and non-roaming scenarios.
In the non-roaming case the role of the V-PCF is performed by the PCF. For the roaming scenarios, the V-PCF interacts with the AMF.
1. When a Policy Control Request Trigger condition is met the AMF updates the AM Policy Association and provides information on the conditions that have changed to the PCF by invoking Npcf_AMPolicyControl_Update.
2. The (V-)PCF stores the information received in step 1 and makes the policy decision. In the non-roaming case, the PCF may subscribe to Analytics from NWDAF as defined in clause 6.1.1.3 of TS 23.503 [20]. If the PCF determines a change to policy counter status reporting is required, it may alter the subscribed list of policy counters using the Initial, Intermediate or Final Spending Limit Report Retrieval procedures as defined in clause 4.16.8.
3. The (V-)PCF responds to the AMF with the updated access and mobility related policy information as defined in clause 6.5 of TS 23.503 [20] and the updated Policy Control Request Trigger parameters. If an AF has previously subscribed to request for allocation of service area coverage outcome event, the (V-)PCF checks if reporting is needed, using the Policy Control Request Trigger that was met (see step 1) as input, then sends a respective notification to the AF using Npcf_AMPolicyAuthorization_Notify, as defined in clause 6.1.3.18 of TS 23.503 [20].
4. The AMF deploys the access and mobility related policy information, which includes storing the Service Area Restrictions and Policy Control Request Trigger of AM Policy Association, provisioning the Service Area Restrictions to the UE and provisioning the RFSP index, UE-AMBR, List of UE-Slice-MBR, Service Area Restrictions to the NG-RAN as defined in TS 23.501 [2] and request for notification of SM Policy association establishment and termination to a list of (DNN, S-NSSAI)(s) together with PCF for the UE binding information. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.16.2.1.2 AM Policy Association Modification with old PCF during AMF relocation | This procedure is applicable to Case C. In this case, AMF relocation is performed without PCF change in handover procedure and registration procedure.
Figure 4.16.2.1.2-1: AM Policy Association Modification with the old PCF during AMF relocation
This procedure concerns both roaming and non-roaming scenarios.
In the non-roaming case the role of the V-PCF is performed by the PCF. For the roaming scenarios, the V-PCF interacts with the AMF:
1. [Conditional] When the old AMF and the new AMF belong to the same PLMN, the old AMF transfers to the new AMF the AM Policy Association information including Policy Control Request Trigger(s) and the PCF ID. For the roaming case, the new AMF receives V-PCF ID.
2. Based on local policies, the new AMF decides to establish an AM Policy Association with the (V-)PCF and contacts the (V‑)PCF identified by the PCF ID received in step 1.
3. The new AMF sends Npcf_AMPolicyControl_Update to the (V-)PCF to update the AM Policy Association with the (V-)PCF. The request may include the following information: Policy Control Request Trigger which has been met, Subscribed Service Area Restrictions (if updated), subscribed RFSP index (if updated) which are retrieved from the UDM during the update location procedure and may include access type and RAT, PEI, ULI, UE time zone, service network. The (V-)PCF updates the stored information provided by the old AMF with the information provided by the new AMF. In the non-roaming case, the PCF may subscribe to Analytics from NWDAF as defined in clause 6.1.1.3 of TS 23.503 [20]. If the PCF determines a change to policy counter status reporting is required, it may alter the subscribed list of policy counters using the Initial, Intermediate or Final Spending Limit Report Retrieval procedures as defined in clause 4.16.8.
When AMF utilizes an NWDAF, it may add the NWDAF serving the UE identified by the NWDAF instance ID. Per NWDAF service instance the Analytics ID(s) are also included.
4. The (V-)PCF may update the policy decision based on the information provided by the new AMF and responds to the Npcf_AMPolicyControl_Update service operation providing access and mobility related policy information as defined in clause 6.5 of TS 23.503 [20]. If an AF has previously subscribed to request for allocation of service area coverage outcome event the (V-)PCF checks if reporting is needed, using the Policy Control Request Trigger that was met (see step 1) as input, then sends a respective notification to the AF using Npcf_AMPolicyAuthorization_Notify, as defined in clause 6.1.3.18 of TS 23.503 [20].
5. The AMF deploys the access and mobility related policy information, which includes storing the Service Area Restrictions, provisioning Service Area Restrictions to the UE and provisioning the RFSP index, UE-AMBR, Service Area Restrictions to the NG-RAN and request for notification of SM Policy association establishment and termination to a list of (DNN, S-NSSAI)(s) together with PCF for the UE binding information. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.16.2.2 AM Policy Association Modification initiated by the PCF | The AM Policy Association modification procedure may be initiated by an internal PCF event or by PCF obtaining pertinent analytics information from an NWDAF.
The following procedure is applicable to AM Policy Association modification due to Case B.
Figure 4.16.2.2-1: AM Policy Association Modification initiated by the PCF
The procedure driven by a PCF internal event applies to both roaming and non-roaming scenarios and when driven by NWDAF or CHF, applies only to non-roaming scenarios.
An AM Policy Association is established, with the V-PCF in case of roaming or with the PCF in a non-roaming case as described in clause 4.16.1.2 before this procedure is triggered.
In the non-roaming case the role of the V-PCF is performed by the PCF. For the roaming scenarios, the V-PCF interacts with the AMF.
NOTE: The V-PCF/PCF stores the access and mobility related policy information provided to the AMF.
1. [Conditional] The PCF determines internally that the new status of the UE context requires new policies, potentially triggered by an AF as described in clause 4.15.6.9 or by a notification from the UDR or optionally, the CHF provides a Spending Limit Report to the PCF as described in clause 4.16.8. This may be triggered by obtaining pertinent analytics information from an NWDAF as described in clause 6.1.1.3 of TS 23.503 [20].
2. The (V-)PCF in case of roaming and PCF in a non-roaming case makes a policy decision. The PCF may also decide to subscribe to a new Analytics ID from NWDAF as described in clause 6.1.1.3 of TS 23.503 [20].
3. The (V-)PCF in the roaming case and the PCF in a non-roaming case sends Npcf_AMPolicyControl_UpdateNotify including AM Policy Association ID associated with the SUPI defined in TS 29.507 [32]. The policy update may include Service Area Restrictions, UE-AMBR, RFSP index value and RFSP Index in Use Validity Time, Slice replacement management, access stratum time distribution indication, Uu time synchronization error budget, clock quality detail level and optionally clock quality acceptance criteria. If an AF has previously subscribed to event request for allocation of service area coverage outcome in step 1, the (V-)PCF checks if the allocated service area coverage was changed and sends a respective notification to the AF using Npcf_AMPolicyAuthorization_Notify as defined in clause 6.1.3.18 of TS 23.503 [20].
4. The AMF deploys and stores the updated access and mobility related policy information, which includes storing the Service Area Restrictions and Policy Control Request Trigger of AM Policy Association, provisioning of the Service Area Restrictions to the UE, provisioning the RFSP index, UE-AMBR, Service Area Restrictions to the NG-RAN, optionally the access stratum time distribution indication, Uu time synchronization error budget, clock quality detail level and optionally clock quality acceptance criteria to the NG-RAN and request for notification of SM Policy association establishment and termination to a list of (DNN, S-NSSAI)(s) together with PCF for the UE binding information. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.16.3 AM Policy Association Termination | |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.16.3.1 General | The following case is considered for AM Policy Association Termination:
1. UE Deregistration from the network.
2. The mobility with change of AMF (e.g. new AMF is in different PLMN or new AMF in the same PLMN).
3. [Optional] 5GS to EPS mobility with N26 if the UE is not connected to the 5GC over a non-3GPP access in the same PLMN.
4. The value of the AM Policy Association indicator changes from "enabled" to "disabled".
In the non-roaming case, the PCF may interact with the CHF to make policy decisions, for Access and Mobility related policies, based on spending limits. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.16.3.2 AMF-initiated AM Policy Association Termination | Figure 4.16.3.2-1: AMF-initiated AM Policy Association Termination
This procedure concerns both roaming and non-roaming scenarios.
In the non-roaming case the role of the V-PCF is performed by the PCF. For the roaming scenarios, the V-PCF interacts with the AMF.
1. The AMF decides to terminate the AM Policy Association due to the reasons listed in clause 4.16.3.1 then if a AM Policy Association was established with the (V-)PCF steps 2 to 3 are performed.
2. The AMF sends the Npcf_AMPolicyControl_Delete service operation including AM Policy Association ID to the (V-)PCF.
3. The (V-)PCF removes the policy context for the UE and replies to the AMF with an Acknowledgement including success or failure. In the non-roaming case, the PCF may unsubscribe to analytics from NWDAF. The (V-)PCF may deregister from the BSF as the PCF that handles the AM Policy Association for this UE. This is performed by using the Nbsf_Management_Deregister service operation, providing the Binding Identifier that was obtained earlier from the BSF when performing the Nbsf_Management_Register service operation.
If the PCF has subscribed to the policy counter status to the CHF, it invokes the procedure defined in clause 4.16.8 to unsubscribe to policy counter status reporting.
Optionally, based on operator policies, as described in clause 6.1.1.4 of TS 23.503 [20], the PCF may store the policy counters and their statuses of spending limits information into the UDR by invoking Nudr_DM_Update.
4. The AMF removes the AM Policy Association for this UE, including the Access and Mobility Control Policy related to the UE. The AMF deletes the subscription to AMF detected events requested for that Policy Association. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.16.3.3 Void | |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.16.4 SM Policy Association Establishment | Figure 4.16.4-1: SM Policy Association Establishment
This procedure concerns both roaming and non-roaming scenarios.
In the non-roaming case the V-PCF is not involved. In the local breakout roaming case, the H-PCF is not involved. In the home routed roaming case, the V-PCF is not involved and the H-PCF interacts with the H-SMF.
This procedure is used in UE requests a PDU Session Establishment as explained in clause 4.3.2.2.1, for non-roaming and local breakout roaming. For home-routed roaming, as explained in clause 4.3.2.2.2.
For local breakout roaming, the interaction with HPLMN (e.g. step 3) is not used. In local breakout roaming, the V-PCF interacts with the UDR of the VPLMN.
1. The SMF determines that the PCC authorization is required and requests to establish an SM Policy Association with the PCF by invoking Npcf_SMPolicyControl_Create operation, including information about the PDU Session as specified in clause 5.2.5.4.2.
The SMF provides Trace Requirements to the PCF when it has received Trace Requirements and it has selected a different PCF than the one received from the AMF.
If the DNN Selection Mode indicates that the DNN is not explicitly subscribed, the PCF may use the local configuration instead of PDU Session policy control data in UDR.
The QoS constraints from the VPLMN are provided by the H-SMF to the H-PCF in the home routed roaming scenario as defined in clause 4.3.2.2.2.
If the SMF utilizes an NWDAF or in case the SMF has received information from AMF or UPF that are consumer of analytic services, the SMF includes the IDs of each of these NWDAFs serving the UE (for SMF, AMF and UPF), identified by the NWDAF instance Id. The Analytics ID(s) are also included per NWDAF service instance.
The SMF provides the PCF binding information (of the PCF for the UE) to the PCF if the Request for notification of SM Policy Association establishment and termination to a DNN, S-NSSAI together with PCF binding information which is received from the AMF.
2. If the PCF does not have the subscriber's subscription related information, it sends a request to the UDR by invoking Nudr_DM_Query (SUPI, DNN, S-NSSAI, Policy Data, PDU Session policy control data, Remaining allowed Usage data) service in order to receive the information related to the PDU Session. The PCF may request notifications from the UDR on changes in the subscription information by invoking Nudr_DM_Subscribe (Policy Data, SUPI, DNN, S-NSSAI, Notification Target Address (+ Notification Correlation Id), Event Reporting Information (continuous reporting), PDU Session policy control data, Remaining allowed Usage data) service. If the PCF does not have the 5G VN group data for the group identified by Internal Group Identifier as indicated by SMF in Npcf_SMPolicyControl_Create, the PCF retrieves the 5G VN group data from UDR and subscribes to changes on the 5G VN group data, see similar way to how the PCF does it during UE Policy Association establishment as described in clause 4.16.11. If the PCF receives the Maximum Group Data Rate in 5G VN group data, the PCF performs the group related policy control as described in clauses 6.1.5 and 6.2.1.11 of TS 23.503 [20].
NOTE 1: For local breakout roaming, PDU Session policy control subscription information and Remaining allowed usage subscription information for monitoring control as defined in clause 6.2.1.3 of TS 23.503 [20] are not available in V-UDR and V-PCF uses locally configured information according to the roaming agreement with the HPLMN operator.
3. If the PCF determines that the policy decision depends on the status of the policy counters available at the CHF and such reporting is not established for the subscriber, the PCF initiates an Initial Spending Limit Report Retrieval as defined in clause 4.16.8.2. If policy counter status reporting is already established for the subscriber and the PCF determines that the status of additional policy counters is required, the PCF initiates an Intermediate Spending Limit Report Retrieval as defined in clause 4.16.8.3.
NOTE 2: The Nudr_DM_Query in step 2 may include the Spending Limit Information, i.e. the policy counters and their latest status. Thus the PCF can provide the SM policy to the SMF before contacting the CHF. The PCF may need to update the SMF depending on the statuses of the policy counters provided by the CHF.
NOTE 3: Potential inconsistencies between the policy counter and its status in the UDR and in the CHF can happen given that the CHF may update the policy counter and its status at any time, as such it is recommended that the PCF contacts the CHF if the policy counters and its status stored in the UDR is used, to be able to receive updated information from the CHF.
4. The PCF makes the authorization and the policy decision. The PCF may reject Npcf_SMPolicyControl_Create request when Validation condition is not satisfied. (see clause 6.1.2.4 of TS 23.503 [20]).
The PCF may invoke Nbsf_Management_Register service operation to create the binding information in BSF.
The PCF may report that a SM Policy Association is established as described in clause 4.16.14.2.
In the non-roaming case, the PCF may subscribe to Analytics from NWDAF as defined in clause 6.1.1.3 of TS 23.503 [20].
In the home-routed roaming scenario, the H-PCF ensures that the QoS constraints provided by the VPLMN are taken into account as described in TS 23.503 [20].
5. The PCF answers with a Npcf_SMPolicyControl_Create response; in its response the PCF may provide policy information defined in clause 5.2.5.4 (and in TS 23.503 [20]). The SMF enforces the decision. The SMF implicitly subscribes to changes in the policy decisions.
NOTE 4: After this step the PCF can subscribe to SMF events associated with the PDU Session.
If the PCF determines based on a local policy, that the PDU Session is potentially impacted by (g)PTP time synchronization service, or the PDU Session belongs to a 5GS DetNet router, the PCF can include a subscription for SMF event for "5GS Bridge/Router information" associated with the PDU Session into the Npcf_SMPolicyControl_Create response. In this case, if the SMF has stored the 5GS Bridge/Router information and has not reported the event to the PCF, the SMF initiates an SM Policy Association Modification procedure and notifies the PCF for the event of "5GS Bridge/Router information Notification". |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.16.5 SM Policy Association Modification | |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.16.5.0 General | The following SM Policy Association Modification procedures concern both roaming and non-roaming scenarios.
In the non-roaming case the V-PCF is not involved. In the local breakout roaming case, the H-PCF is not involved. In the home routed roaming case, the V-PCF is not involved and the H-PCF interacts with the H-SMF.
The SM Policy Association Modification procedure may be initiated either by the SMF or by the PCF. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.16.5.1 SMF initiated SM Policy Association Modification | The SMF may initiate the SM Policy Association Modification procedure if a Policy Control Request Trigger is met.
NOTE 1: When SMF instance is changed within the same SMF set the callback URI can be updated via this procedure.
Figure 4.16.5.1-1: SMF initiated SM Policy Association Modification
For local breakout roaming, the interaction with HPLMN (e.g. step 2) is not used. In local breakout roaming, the V-PCF interacts with the UDR of the VPLMN.
1. When a Policy Control Request Trigger condition is met the SMF requests to update (Npcf_SMPolicyControl_Update) the SM Policy Association and provides information on the conditions that have been met as specified in clause 5.2.5.4.5.
If the SMF is notified by NRF that the stored PCF instance is not reachable, it should query the NRF for PCF instances within the PCF set and select another instance (see clause 6.3.1.0 of TS 23.501 [2]).
The QoS constraints from the VPLMN are provided by the H-SMF to the H-PCF in the home routed roaming scenario as defined in clause 4.3.2.2.2.
2. When an AF has subscribed to an event that is met due to the report from the SMF, the PCF reports the event to the AF or TSCTSF by invoking the Npcf_PolicyAuthorization_Notify service operation.
If the SMF has reported that new 5GS Bridge/Router information has been detected and no AF session exists for this PDU session yet:
- If integration with TSN applies (see clause 5.28 of TS 23.501 [2]), then the PCF informs a pre-configured TSN AF using the Npcf_PolicyAuthorization_Notify (User-plane Node ID, the port number of the DS-TT port, MAC address of the DS-TT Ethernet port for the PDU Session and UE-DS-TT Residence Time (if available)) service operation for the event of "5GS Bridge/Router information Notification" as described in clause 6.1.3.18 of TS 23.503 [20].
- Otherwise, i.e. if the integration with TSN does not apply, the PCF may inform discovered and selected TSCTSF (as described in clause 6.3.24 of TS 23.501 [2]) using the Npcf_PolicyAuthorization_Notify (User Plane Node ID, UE-DS-TT Residence Time (if available), the port number for the PDU session and MAC address of the DS-TT Ethernet port for Ethernet type PDU Session or IP address for IP type PDU Session, MTU size for IPv4 or IPv6 (if available)) service operation for the event of "5GS Bridge/Router information Notification" as described in clause 6.1.3.18 of TS 23.503 [20]. In the case of private IPv4 address being used for IP type PDU Session, the Npcf_PolicyAuthorization_Notify also contains DNN and S-NSSAI of the PDU Session.
NOTE 2: For a given DNN and S-NSSAI, it is assumed that the network only needs to deploy one or TSCTSF Set in this Release of the specification.
When the TSN AF or TSCTSF receives the Npcf_PolicyAuthorization_Notify message and no AF session exists for this PDU Session, the TSN AF shall use the Npcf_PolicyAuthorization service described in clause 5.2.5.3 to request creation of a new AF session specific to the received MAC address of the DS-TT Ethernet port of the PDU Session, while the TSCTSF shall use the Npcf_PolicyAuthorization service to request creation of a new AF session specific to the received MAC address of the DS-TT Ethernet port (if available, for Ethernet type PDU Session) or IP address (for IP type PDU Session) of the PDU Session. In the case of private IPv4 address being used for IP type PDU Session, the TSCTSF shall use the Npcf_PolicyAuthorization service to request creation of a new AF session specific to the received IP address, DNN and S-NSSAI of the IP type PDU Session. The TSN AF or TSCTSF shall then use the Npcf_PolicyAuthorization service to subscribe for notifications for 5GS Bridge/Router information Notification event over the newly established AF session. The TSN AF or TSCTSF may provide a Port or User-Plane Management Information Container for the PDU Session and related port number in the Npcf_PolicyAuthorization creation request.
If the SMF has reported PMIC with port number or UMIC, then the PCF also provides these information elements to the TSN AF or TSCTSF.
When integration with TSN applies (see clause 5.28 of TS 23.501 [2]), the TSN AF calculates the bridge delay for each port pair, using the UE-DS-TT Residence Time of the DS-TT Ethernet port(s) for the 5GS bridge indicated by the 5GS user-plane Node ID.
3. If the PCF determines a change to policy counter status reporting is required, it may alter the subscribed list of policy counters using the Initial, Intermediate or Final Spending Limit Report Retrieval procedures as defined in clause 4.16.8.
4. The PCF makes a policy decision as described in TS 23.503 [20]. The PCF may determine that updated or new policy information needs to be sent to the SMF.
If the SMF reported accumulated usage for the PDU session in step 1 the PCF deducts the value from the remaining allowed usage for the subscriber, DNN and S-NSSAI in the UDR by invoking Nudr_DM_Update (SUPI, DNN, S-NSSAI, Policy Data, Remaining allowed Usage data, updated data) service operation.
If the SMF reported accumulated usage for a MK(s) in step 1 the PCF deducts the value from the remaining allowed usage for the MK in the UDR by invoking Nudr_DM_Update (SUPI, DNN, S-NSSAI, Policy Data, Remaining allowed Usage data, updated data (including MK(s))) service operation.
If SMF reported Non-3GPP Device Identifier and it's corresponding user plane address in step 1, PCF retrieves, if not already available, Non-3GPP Device Identifier Information for the corresponding Non-3GPP Device Identifier from the UDR by invoking Nudr_DM_Query (Data Set = "Application Data", Data Subset = "Non-3GPP Device Identifier Information", Data Key = SUPI, Data Sub-key = Non-3GPP Device Identifier).
When new PCF instance is selected in step 1, the new PCF should invoke Nbsf_Management_Update service operation to update the binding information in BSF.
In the non-roaming case, the PCF may subscribe to Analytics from NWDAF as defined in clause 6.1.1.3 of TS 23.503 [20].
In the home-routed roaming scenario, the H-PCF ensures that the QoS constraints provided by the VPLMN are taken into account as described in TS 23.503 [20].
NOTE 3: For local breakout roaming, PDU Session policy control subscription information and Remaining allowed usage subscription information for monitoring control as defined in clause 6.2.1.3 of TS 23.503 [20] are not available in V-UDR and V-PCF uses locally configured information according to the roaming agreement with the HPLMN operator.
5. The PCF answers with a Npcf_SMPolicyControl_Update response with updated policy information about the PDU Session determined in step 4. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.16.5.2 PCF initiated SM Policy Association Modification | The PCF may initiate SM Policy Association Modification procedure based on internal PCF event or triggered by other peers of the PCF (AF, NWDAF, CHF, UDR and TSCTSF).
Figure 4.16.5.2-1: PCF initiated SM Policy Association Modification
This procedure may be triggered by a local decision of the PCF or based on triggers from other peers of the PCF (AF, NWDAF, CHF, UDR and TSCTSF):
An SM Policy Association is established, with the PCF as described in clause 4.16.4 before this procedure is triggered.
For local breakout roaming, the interaction with HPLMN (e.g. step 1b and step 2) is not used. In local breakout roaming, the V-PCF interacts with the UDR of the VPLMN.
1a. Alternatively, optionally, the AF, NEF or TSCTSF provides/revokes service information to the PCF e.g. due to AF session signalling, by invoking Npcf_PolicyAuthorization_Create Request or Npcf_PolicyAuthorization_Update Request or Npcf_PolicyAuthorization_Subscribe Request service operation. The PCF responds to the AF, NEF or TSCTSF.
1b. Alternatively, optionally, the CHF provides a Spending Limit Report to the PCF as described in clause 4.16.8. and responds to the CHF.
1c. Alternatively, optionally, the UDR notifies the PCF about a policy subscription change by invoking Nudr_DM_Notify (Notification correlation Id, Policy Data, SUPI, updated data, "PDU Session Policy Control Data" | "Remaining allowed Usage data"); if the PCF uses the 5G VN group data and subscribes to 5G VN group data change, the UDR notifies the PCF about the 5G VN group data change by invoking Nudr_DM_Notify (Notification correlation Id, Subscription Data, Group Data); if the PCF uses Non-3GPP Device Identifier Information and subscribes to Non-3GPP Device Identifier Information change, the UDR notifies the PCF about the Non-3GPP Device Identifier Information change by invoking Nudr_DM_Notify (Notification correlation Id, Application Data, Non-3GPP Device Identifier Information, SUPI, Non-3GPP Device Identifier). The PCF responds to the UDR.
1d. Alternatively, optionally, some internal event (e.g. timer, or local decision based on analytics information requested and received from NWDAF) occurs at the PCF. The analytics (i.e. Analytics ID) which can be requested from NWDAF are described in clause 6.1.1.3 of TS 23.503 [20].
2. If the PCF determines a change to policy counter status reporting is required, it may alter the subscribed list of policy counters using the Initial, Intermediate or Final Spending Limit Report Retrieval procedures as defined in clause 4.16.8.
NOTE 1: The PCF ensures that information received in step 1 and 2 can be used by later policy decisions.
NOTE 2: For local breakout roaming, PDU Session policy control subscription information and Remaining allowed usage subscription information for monitoring control as defined in clause 6.2.1.3 of TS 23.503 [20] are not available in V-UDR and V-PCF uses locally configured information according to the roaming agreement with the HPLMN operator.
3. The PCF makes a policy decision. The PCF may determine that updated or new policy information need to be sent to the SMF. In the non-roaming case, the PCF may also decide to subscribe to a new Analytics ID from NWDAF as described in clause 6.1.1.3 of TS 23.503 [20].
If the AF provided a Background Data Transfer Reference ID in step 1a, the PCF may retrieve it from the UDR by invoking the Nudr_DM_Query (BDT Reference Id, Policy Data, Background Data Transfer) service.
4. If the PCF has determined that SMF needs updated policy information in step 3 or if the PCF has received a Port Management Information Container for the PDU Session and related port number from the AF or TSCTSF in step 1a, the PCF issues a Npcf_SMPolicyControl_UpdateNotify request with possibly updated policy information about the PDU Session.
If the PCF has received a subscription for 5GS Bridge/Router information Notification in Step 1a, the PCF can include a subscription for SMF event for "5GS Bridge/Router information" associated with the PDU Session into the Npcf_SMPolicyControl_UpdateNotify request. In this case, if the SMF has stored the 5GS Bridge/Router information and has not reported the event to the PCF, the SMF notifies the PCF for the event of "5GS Bridge/Router Information ".
If the PCF has received a Npcf_PolicyAuthorization_Unsubscribe request to unsubscribe for 5GS Bridge/Router information Notification, the PCF can remove the subscription for SMF event for "5GS Bridge/Router information" associated with the PDU Session and issue a Npcf_SMPolicyControl_UpdateNotify request with the updated policy information about the PDU Session.
NOTE 3: If the TSCTSF receives a Requested 5GS delay and the TSCTSF does not have the 5GS Bridge/Router information for the AF-session, the TSCTSF can subscribe for the 5GS Bridge/Router information from the PCF by triggering a Npcf_PolicyAuthorization_Subscribe request.
If the PCF has received a subscription to notification on BAT offset along with the TSC Assistance Container from TSCTSF in step 1a, the PCF can include a subscription to notification on BAT offset associated with the PDU Session into the Npcf_SMPolicyControl_UpdateNotify request.
5. The SMF acknowledges the PCF request with a Npcf_SMPolicyControl_UpdateNotify response.
If the Npcf_SMPolicyControl_UpdateNotify request is received from new PCF instance in the PCF Set, the SMF store the SM policy association towards the new PCF instance. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.16.6 SM Policy Association Termination | Figure 4.16.6-1: SM Policy Association Termination
This procedure concerns both roaming and non-roaming scenarios.
In the non-roaming case the V-PCF is not involved. In the local breakout roaming case, the H-PCF is not involved. In the home routed roaming case, the V-PCF is not involved and the H-PCF interacts only with the H-SMF.
The procedure for Session Management Policy Termination may be initiated by:
- (Case A) the PCF.
- (Case B) the SMF.
For local breakout roaming, the interaction with HPLMN (e.g. step 6) is not used. In local breakout roaming, the V-PCF interacts with the UDR of the VPLMN.
1. (Case A) The PCF may invoke the Npcf_SMPolicyControl_UpdateNotify service operation to request the release of a PDU Session. The SMF acknowledges the request.
The rest of the procedure corresponds to both Case A &B.
2. The SMF may invoke the Npcf_SMPolicyControl_Delete service operation to request the deletion of the SM Policy Association with the PCF. The SMF provides relevant information to the PCF.
3. When receiving the request from step2, the PCF finds the PCC Rules that require an AF to be notified and removes PCC Rules for the PDU Session.
If the SMF reported accumulated usage for the PDU session in step 1 the PCF deducts the value from the remaining allowed usage for the subscriber, DNN and S-NSSAI in the UDR by invoking Nudr_DM_Update (SUPI, DNN, S-NSSAI, Policy Data, Remaining allowed Usage data, updated data) service operation.
If the SMF reported accumulated usage for a MK(s) in step 1 the PCF deducts the value from the remaining allowed usage for the MK in the UDR by invoking Nudr_DM_Update (SUPI, DNN, S-NSSAI, Policy Data, Remaining allowed Usage data, updated data (including MK(s))) service operation.
NOTE: For local breakout roaming, PDU Session policy control subscription information and Remaining allowed usage subscription information for monitoring control as defined in clause 6.2.1.3 of TS 23.503 [20] are not available in V-UDR and V-PCF uses locally configured information according to the roaming agreement with the HPLMN operator.
4. The SMF removes all policy information about the PDU Session associated with the PDU Session.
5. The PCF notifies the AF as explained in clause 7.3.1 steps 6-7 of TS 23.203 [24].
The PCF may invoke Nbsf_Management_Deregister service operation to delete the binding created in BSF.
The PCF may report that a SM Policy Association is terminated as described in clause 4.16.14.2.
In the non-roaming case, the PCF may unsubscribe to analytics from NWDAF.
6. The PCF may invoke the procedure defined in clause 4.16.8 to unsubscribe to policy counter status reporting (If this is the last PDU Session for this subscriber requiring policy counter status reporting) or to modify the subscription to policy counter status reporting, (if any remaining existing PDU Sessions for this subscriber requires policy counter status reporting).
7. The PCF removes the information related to the terminated PDU Session and acknowledges to the SMF that the PCF handling of the PDU Session has terminated. This interaction is the response to the SMF request in step 2.
8. Optionally, based on operator policies, as described in clause 6.1.1.4 of TS 23.503 [20], the PCF may store the policy counters and their statuses of spending limits information into the UDR by invoking Nudr_DM_Update.
9. The PCF may (e.g. if it is the last PDU Session on the (DNN, S-NSSAI) couple) unsubscribe to the notification of the PDU Session related data modification from the UDR by invoking Nudr_DM_Unsubscribe (Subscription Correlation Id) if it had subscribed such notification. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.16.7 Negotiations for future background data transfer | |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.16.7.1 General | The procedure for future background data transfer as specified in clause 4.16.7.2 enables the negotiation between the NEF and the H-PCF about the transfer policies for the future background data transfer (as described in clause 6.1.2.4 of TS 23.503 [20]). The transfer policies consist of a desired time window for the background data transfer, a reference to a charging rate for the time window, network area information and optionally a maximum aggregated bitrate, as described in clause 6.1.2.4 of TS 23.503 [20].
This negotiation is preliminarily conducted (when AF initiates a procedure to NEF) before the UE's PDU Session establishment. When the AF wants to apply the Background Data Transfer Policy to an existing PDU Session, then at the time the background data transfer is about to start the AF invokes the Npcf_PolicyAuthorization_Create service directly with PCF, or via the NEF, to apply the background data transfer policy for an individual UE. When the AF wants to apply the Background Data Transfer Policy to a future PDU Session, then the AF invokes Nnef_ApplyPolicy_Create service to provide, to the NEF, the Background Data Transfer Reference ID together with the External Identifier or External Group Identifier of the UE(s) that are subject to the policy.
The procedure for BDT warning notification as specified in clause 4.16.7.3 enables the PCF to notify the AF that the network performance in the area of interest goes below the criteria set by the operator as described in clause 6.1.2.4 of TS 23.503 [20]. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.16.7.2 Procedures for future background data transfer | Figure 4.16.7.2-1: Negotiation for future background data transfer
1. The AF invokes the Nnef_BDTPNegotiation_Create (ASP Identifier, Number of UEs, Volume per UE, Desired time window and optionally External Group Identifier, Network Area Information, Request for notification, MAC address or IP 3-tuple of Application server). The Request for notification is an indication that BDT warning notification should be sent to the AF.
2a. Based on an AF request, the NEF requests to translate the External Group Identifier into the Internal Group Identifier using Nudm_SDM_Get (Group Identifier Translation, External Group Identifier).
2b. The NEF invokes the Npcf_BDTPolicyControl_Create (ASP Identifier, Number of UEs, Volume per UE, Desired time window and optionally Internal Group Identifier, the Network Area Information, Request for notification, MAC address or IP 3-tuple of Application server) with the H-PCF to authorize the creation of the policy regarding the background data transfer. If the PCF was provided with Request for notification, then PCF may send BDT warning notification to the AF as described in clause 4.16.7.3.
3 The H-PCF may request from the UDR the stored Background Data Transfer policies for all the ASPs using Nudr_DM_Query (Policy Data, Background Data Transfer) service operation.
NOTE 1: If only one PCF is deployed in the PLMN, the Background Data Transfer policy can be locally stored and no interaction with UDR is required.
4. The UDR provides all the stored Background Data Transfer policies and corresponding related information (i.e. volume of data to be transferred per UE, the expected amount of UEs) to the H-PCF.
5. The H-PCF determines, based on information provided by the AF and other available information one or more Background Data Transfer policies. The PCF may interact with the NWDAF and request the Network Performance analytics information for the Desired time window and the Network Area Information as defined in TS 23.288 [50].
NOTE 2: When the External Group Identifier was provided and the Network Area Information was not provided by the AF at step 1, the NWDAF derives the Network Area Information from the Internal Group ID as defined in clause 6.6 of TS 23.288 [50].
NOTE 3: The maximum aggregated bitrate is not enforced in the network.
6. The H-PCF send the acknowledge message to the NEF with the acceptable Background Data T Transfer policies and a Background Data Transfer Reference ID.
7. The NEF sends a Nnef_BDTPNegotiation_Create response to the AF to provide one or more background data transfer policies and the Background Data Transfer Reference ID to the AF. The AF stores the Background Data Transfer Reference ID for the future interaction with the PCF. If the NEF received only one background data transfer policy from the PCF, steps 8-11 are not executed and the flow proceeds to step 12. Otherwise, the flow proceeds to step 8.
NOTE 4: If the NEF receives only one Background Data T Transfer policy, the AF is not required to confirm.
8. The AF invokes the Nnef_BDTPNegotiation_Update service to provide the NEF with Background Data Transfer Reference ID and the selected background data transfer policy.
9. The NEF invokes the Npcf_BDTPolicyControl_Update service to provide the H-PCF with the selected background data transfer policy and the associated Background Data Transfer Reference ID.
10. The H-PCF sends the acknowledge message to the NEF.
11. The NEF sends the acknowledge message to the AF.
12. The H-PCF stores the Background Data Transfer Reference ID together with the new Background Data T Transfer policy, the corresponding related information (i.e. volume of data to be transferred per UE, the expected amount of UEs), optionally MAC address or IP 3-tuple of Application server the information of request for notification, together with the relevant information received from the AF (as defined in clause 6.1.2.4 of TS 23.503 [20]) in the UDR by invoking Nudr_DM_Update (BDT Reference id, Policy Data, Background Data Transfer). This step is not executed, when the PCF decides to locally store the Background Data Transfer policy.
13. The UDR sends a response to the H-PCF as its acknowledgement. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.16.7.3 Procedure for BDT warning notification | Figure 4.16.7.3-1: The procedure for BDT warning notification
1. The negotiation for Background Data Transfer (BDT) described in clause 4.16.7.2 is completed. In addition, the PCF has subscribed to analytics on "Network Performance" from NWDAF for the area of interest and time window of a background data transfer policy following the procedure and services described in TS 23.288 [50], including a Reporting Threshold in the Analytics Reporting information. The value for Reporting Threshold is set by the PCF based on operator configuration.
2. The PCF is notified with the network performance analytics in the area of interest from the NWDAF when the NWDAF determines that the network performance goes below the threshold as described for the Network Performance analytics in TS 23.288 [50].
3. The H-PCF may request from the UDR the stored BDT policies using Nudr_DM_Query (Policy Data, Background Data Transfer) service operation.
4. The UDR provides all the Background Transfer Policies together with the relevant information received from the AF (as defined in clause 6.1.2.4 of TS 23.503 [20]) to the H-PCF.
5. The H-PCF identifies the BDT policies affected by the notification received from NWDAF. For each of them, the H-PCF determines the ASP of which the background traffic will be influenced by the degradation of network performance and which requested the H-PCF to send the notification. The PCF then performs the following steps for each of the determined ASPs, i.e. Steps 6 - 16 can occur multiple times (i.e. once per ASP).
6. The PCF decides based on operator policies, whether a new list of candidate Background Data Transfer policies can be calculated for the ASP. If the PCF does not find any new candidate BDT policy, the previously negotiated BDT policy shall be kept, no interaction with that ASP shall occur and the procedure stops for that BDT policy.
NOTE 1: The BDT policies of an ASP which did not request to be notified are kept and no interaction with this ASP occurs.
7. The PCF sets the no longer valid BDT policy in the UDR as invalidated by invoking Nudr_DM_Update (Background Data Transfer Reference ID, invalidation flag) service.
NOTE 2: The BDT policies that are applicable for future sessions are checked by the PCF in step 6.
8. The UDR sends a response to the H-PCF as acknowledgement.
9. The PCF sends the notification to the NEF by invoking Npcf_PolicyControl_Notify (Background Data Transfer Reference ID, list of candidate Background Data Transfer policies) service operation.
10. The NEF sends the BDT warning notification to the AF by invoking Nnef_BDTPNegotiation_Notify (Background Data Transfer Reference ID, list of candidate Background Data Transfer policies) service operation.
11. The AF checks the new Background Data Transfer policies included in the candidate list in the BDT warning notification.
12. If the AF selects any of the new Background Data Transfer policies, the steps 8-13 from clause 4.16.7.2 are executed.
13. If the AF doesn't select any of the new Background Data Transfer policies, the steps 8-11 from clause 4.16.7.2 are executed, with the AF indicating that none of the candidate Background Data Transfer policies is acceptable.
14.-15. If the step 13 is executed, the PCF removes the no longer valid BDT policy from UDR for the corresponding Background Data Transfer Reference ID.
NOTE 3: The PCF can also remove the no longer valid BDT policy after an operator configurable time for the case that the AF does not respond.
16. If there is a new Background Data Transfer policy stored in the UDR or a BDT policy removed from the UDR, the PCFs are notified by the UDR accordingly. The PCFs check if the corresponding URSP rules need to be updated or removed and if so, use the procedure defined in clause 4.16.12.2 to update URSP rules for the relevant UEs.
The AF can send a Stop notification by invoking Nnef_BDTPNegotiation_Update service, when the AF requests not to receive the BDT warning notification anymore. Then, the NEF invokes Npcf_BDTPolicyControl_Update service in order to provide this information for the H-PCF. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.16.8 Procedures on interaction between PCF and CHF | |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.16.8.1 General | The PCF may interact with the CHF to make session management policy decisions, UE policy decisions and Access and Mobility related policy decisions based on spending limits. For session management policy decisions, in the Home Routed roaming and Non-roaming case, the H-PCF will interact with the CHF in HPLMN. For Access and Mobility related policy decisions and UE policy decisions, the non-roaming case is supported when the PCF interacts with the CHF in the HPLMN. In addition, for UE policy decisions in Home Routed and local breakout roaming case, the H-PCF interacts with the CHF in the HPLMN. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.16.8.2 Initial Spending Limit Retrieval | This clause describes the signalling flow for the PCF to retrieve the status of the policy counters available at the CHF and to subscribe to spending limit reporting (i.e. to notifications of policy counter status changes) by the CHF. If the PCF provides the list of policy counter identifier(s), the CHF returns the policy counter status per policy counter identifier provided by the PCF. If the PCF does not provide the list of policy counter identifier(s), the CHF returns the policy counter status of all policy counter(s), which are available for this subscriber.
The Initial Spending Limit Report Retrieval includes all subscriber Identifiers associated with the UE available at the PCF.
NOTE: If the CHF returns the status of all available policy counters some of these might not be relevant for a policy decision (e.g. those used in a policy decision only when roaming).
Figure 4.16.8.2.1: Initial Spending Limit Report Retrieval
1. The PCF retrieves subscription information that indicates that policy decisions depend on the status of policy counter(s) held at the CHF and optionally the list of policy counter identifier(s).
2. The PCF sends Nchf_SpendingLimitControl_Subscribe if this is the first time policy counter status information is requested for the user identified by a SUPI. It includes: the subscriber ID (e.g. SUPI), the EventId "policy counter status change" and optionally, the list of policy counter identifier(s) as Event Filter, the Notification Target Address, Event Reporting Information (continuous reporting).
The CHF responds to the Nchf_SpendingLimitControl_Subscribe service operation including the Subscription Correlation Id) and as Event Information provides a policy counter status and optionally pending policy counter statuses and their activation times, per required policy counter identifier and stores the PCF's subscription to spending limit reports for these policy counters. If no policy counter identifier(s) was provided the CHF returns the list of the policy counter status, optionally including pending policy counter statuses and their activation times, for all policy counter(s), which are available for this subscriber and stores the PCF's subscription to spending limit reports of all policy counters provided to the PCF. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.16.8.3 Intermediate Spending Limit Report Retrieval | This clause describes the signalling flow for the PCF to retrieve the status of additional policy counters available at the CHF or to unsubscribe from spending limit reporting. If the PCF provides the list of policy counter identifier(s), the CHF returns the policy counter status per policy counter identifier provided by the PCF.
NOTE: If the CHF returns the status of all available policy counters some of these might not be relevant for a policy decision, (e.g. those used in a policy decision only when roaming).
Figure 4.16.8.3.1: Intermediate Spending Limit Report Retrieval
1. The PCF determines that policy decisions depend on the status of additional policy counter(s) held at the CHF or that notifications of policy counter status changes for some policy counters are no longer required.
2. The PCF sends Nchf_SpendingLimitControl_Subscribe to the CHF, including the Subscription Correlation Id, the EventId "policy counter status change" and an updated list of policy counter identifier(s) as EventFilters, that overrides the previously stored list of policy counter identifier(s).
The CHF responds to the Nchf_SpendingLimitControl_Subscribe service operation and provides as Event Information the policy counter status and optionally pending policy counter statuses and their activation times, per required policy counter identifier and stores or removes the PCF's subscription to spending limit reporting by comparing the updated list with the existing PCF subscriptions. If no policy counter identifier(s) was provided, the CHF returns the policy counter status, optionally including pending policy counter statuses and their activation times, for all policy counter(s), which are available for this subscriber and stores the PCF's subscription to spending limit reports of all policy counters provided to the PCF. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.16.8.4 Final Spending Limit Report Retrieval | This clause describes the signalling flow for the PCF to cancel the subscriptions to status changes for the policy counters available at the CHF.
Figure 4.16.8.4.1: Final Spending Limit Report Retrieval
1. The PCF decides that notifications of policy counter status changes are no longer needed.
2. The PCF sends Nchf_SpendingLimitControl_Unsubscribe including the SubscriptionCorrelationId to the CHF to cancel the subscription to notifications of policy counter status changes from the CHF.
3. The CHF removes the PCF's subscription to spending limit reporting and responds to the Nchf_SpendingLimitControl_Unsubscribe service operation to the PCF. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.16.8.5 Spending Limit Report | This clause describes the signalling flow for the CHF to notify the change of the status of the subscribed policy counters available at the CHF for that subscriber. Alternatively, the signalling flow can be used by the CHF to provide one or more pending statuses for a subscribed policy counter together with the time they have to be applied.
Figure 4.16.8.5.1: Spending Limit Report
1. The CHF detects that the status of a policy counter(s) has changed and the PCF subscribed to notifications of changes in the status of this policy counter. Alternatively, the CHF may detect that a policy counter status will change at a future point in time and decides to instruct the PCF to apply one or more pending statuses for a requested policy counter.
2. The CHF sends Nchf_SpendingLimitControl_Notify with the SUPI, Notification Target Address and in the Event Information the policy counter status and optionally pending policy counter statuses and their activation times, for each policy counter that has changed and for which the PCF subscribed to spending limit reporting. Alternatively, the CHF sends one or more pending statuses for any of the subscribed policy counters together with the time they have to be applied.
3. The PCF acknowledges sending Nchf_SpendingLimitControl_Notify response and takes that information into account as input for a policy decision. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.16.8.6 CHF report the removal of the subscriber | This clause describes the signalling flow for the CHF to report the removal of the subscriber.
Figure 4.16.8.6-1: CHF report the removal of the subscriber
1. The CHF decides that a subscriber is removed.
2. The CHF sends the Nchf_SpendingLimitControl_Notify Request to H-PCF to notify the removal of the subscriber. The H-PCF removes the subscription to notification of policy counter status from CHF.
NOTE: Notification on the removing of a subscriber causes the H-PCF to make the applicable policy decision and act accordingly.
3. The H-PCF responds to CHF using Nchf_SpendingLimitControl_Notify to acknowledge the receiving of the notification. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.16.9 Update of the subscription information in the PCF | Figure-4.16.9-1: Procedure for update of the subscription information in the PCF
NOTE: The V-PCF is not used for session management related policy decisions in this procedure.
0. The PCF performs the subscription to notification to the profile modified in the UDR by invoking Nudr_DM_Subscribe (Policy Data, SUPI, Notification Target Address (+ Notification Correlation Id), Event Reporting Information (continuous reporting), one or several of the following: "PDU Session Policy Control data", "Remaining allowed Usage data" or "UE context Policy Control data") service.
1. The UDR detects that the related subscription profile has been changed.
2. If subscribed by the PCF, the UDR notifies the PCF on the changed profile by invoking Nudr_DM_Notify (Notification Correlation Id, Policy Data, SUPI, updated data and one or several of the following data subtypes "PDU Session Policy Control Data" or "Remaining allowed Usage data" or "UE Context Policy Control data") service.
3. The PCF stores the updated profile.
4. If the updated subscriber profile requires the status of new policy counters available at the CHF then an Initial/Intermediate Spending Limit Report Retrieval is initiated by the PCF as defined in clauses 4.16.8,2 and 4.16.8.3. If the updated subscriber profile implies that no policy counter status is needed an Intermediate Spending Limit Report Request Retrieval is initiated by the PCF to unsubscribe or, if this is the last policy counter status, a Final Spending Limit Report Retrieval is initiated by the PCF as specified in clause 4.16.8.4.
5. PCF makes an authorization and policy decision.
6. The PCF provides new session management related policy decisions to the SMF, using the Policy related interaction in PDU Session Modification procedure in clause 4.16.6, new access and mobility related policy information to the AMF using the AM Policy Association Modification procedure in clause 4.16.2 or new UE policy information to the AMF using the UE Policy Association Modification procedure in clause 4.16.12. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.16.10 Void | |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.16.11 UE Policy Association Establishment | |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.16.11.1 General | The UE Policy Association Establishment procedure, which may be performed for a UE registered in the same AMF or different AMFs for 3GPP access and non-3GPP access, concerns the following scenarios:
1. UE initial registration with the network.
2. The AMF relocation with PCF change in handover procedure and registration procedure.
3. UE registration with 5GS when the UE moves from EPS to 5GS and there is no existing UE Policy Association between AMF and PCF for this UE.
4. A change of the value of the UE Policy Association indicator received from UDM from "disabled" to "enabled" while the UE is registered.
The H-PCF may interact with the CHF in HPLMN to make a decision about UE Policies based on spending limits.
Figure 4.16.11-1: UE Policy Association Establishment
This procedure concerns both roaming and non-roaming scenarios. The AMF stores the UE Policy Container in the UE Context when received from the UE.
In the non-roaming case the V-PCF is not involved and the role of the H-PCF is performed by the PCF. For the roaming scenarios, the V-PCF interacts with the AMF and the H-PCF interacts with the V-PCF:
1. The AMF establishes UE Policy Association with the (V-)PCF considering the value of the UE Policy Association Indicator from UDM, the reception of the UE Policy Container from the UE and the AMF local configuration as defined in clause 6.1.2.2.5 of TS 23.503 [20].
NOTE 1: In roaming scenario, the AMF local configuration can indicate whether UE Policy delivery is needed based on the roaming agreement with home PLMN of the UE as defined in TS 23.503 [20].
2. The AMF sends a Npcf_UEPolicyControl Create Request with the following information: SUPI, may include Access Type and RAT, PEI, ULI, UE time zone, Serving Network (PLMN ID, or PLMN ID and NID, see clause 5.34 of TS 23.501 [2]), the Internal-Group-ID-list and UE Policy Container (the list of stored PSIs, operating system identifier, Indication of UE support for ANDSP, indication of UE capability of reporting URSP rule enforcement to network, indication of support of URSP delivery in EPS). In roaming scenario, based on operator policies, the AMF may provide to the V-PCF the PCF ID of the selected H-PCF. The V-PCF contacts the H-PCF. In roaming case, steps 3 and 4 are executed, otherwise step 5 follows.
If the AMF, based on configuration, is aware that the UE is accessing over a gNB using satellite backhaul, the AMF includes the Satellite backhaul category as described in clause 5.43 of TS 23.501 [2].
If during UE initial registration the AMF receives from the UE the indication of support of N3IWF selection based on the slices the UE wishes to use over untrusted non-3GPP access and/or of UE support for TNGF selection based on the slices the UE wishes to use over trusted non-3GPP access, the AMF shall indicate to the PCF that the UE supports N3IWF selection based on the slices the UE wishes to use over untrusted non-3GPP access and/or UE support for TNGF selection based on the slices the UE wishes to use over trusted non-3GPP access. The AMF may request to the PCF to receive a notification when the provisioning in the UE of ANDSP/WLANSP with slice information has finished.
3. The V-PCF forwards the information received from AMF in step 2 to the H-PCF. When a UE Policy Container is received at initial registration, the H-PCF may store the PEI, the OSId, indication of UE capability of reporting URSP rule enforcement to network, indication of support of URSP delivery in EPS or the indication of UE support for ANDSP in the UDR using Nudr_DM_Create including DataSet "Policy Data" and Data Subset "UE context policy control data".
3a. The H-PCF may invoke the Nudr_DM_Query service to the H-UDR. The H-UDR may respond with the requested policy control subscription data as in clause 6.2.1.3 of TS 23.503 [20] and/or application data as in clause 6.2.1.6 of TS 23.503 [20].
The V-PCF may retrieve the Application guidance on URSP Rule for inbound roamers of the PLMN of the SUPI, if not available, using Nudr_DM_Query or Nudr_DM_Subscribe including the Data Set "Application Data" and Data Subset "Service Specific Information" and DataKey set to "PLMN ID(s) of inbound roamers".
3b, If the H-PCF determines that the decision about UE policy control depends on the status of the policy counters available at the H-CHF and if such reporting is not established for the subscriber, the H-PCF initiates an Initial Spending Limit Report Retrieval as defined in clause 4.16.8.2. If policy counter status reporting is already established for the subscriber and the H-PCF determines that the statuses of additional policy counters are required, the H-PCF initiates an Intermediate Spending Limit Report Retrieval as defined in clause 4.16.8.3.
NOTE 2: The Nudr_DM_Query in step 3a may include the Spending Limit Information, i.e. the policy counters and their latest status. Thus the PCF can provide the UE policy to the AMF before contacting the CHF. The PCF may need to update the AMF depending on the statuses of the policy counters provided by the CHF.
NOTE 3: Potential inconsistencies between the policy counter and its status in the H-UDR and in the H-CHF can happen given that the H-CHF may update the policy counter and its status at any time, as such it is recommended that the H-PCF contacts the H-CHF if the policy counters and its status stored in the H-UDR is used, to be able to receive updated information from the H-CHF.
4. The H-PCF sends a Npcf_UEPolicyControl Create Response to the V-PCF. The H-PCF may provide the Policy Control Request Trigger parameters in the Npcf_UEPolicyControl Create Response.
The (H-)PCF in roaming and the PCF in non-roaming may register to the BSF as the PCF serving this UE, if not already registered at the AM Policy Association establishment. This is performed by using the Nbsf_Management_Register operation, providing as inputs the UE SUPI/GPSI and the PCF identity.
5. The (V-) PCF sends a Npcf_UEPolicyControl Create Response to the AMF. The (V-)PCF relays the Policy Control Request Trigger parameters in the Npcf_UEPolicyControl Create Response.
The (V-)PCF also subscribes to notification of N1 message delivery of policy information to the UE using Namf_Communication_N1N2MessageSubscribe service which is not shown in this figure.
6. The (H-)PCF gets policy subscription related information and the latest list of PSIs from the UDR using Nudr_DM_Query service operation (SUPI, Policy Data, UE context policy control data, Policy Set Entry) if either or both are not available and makes a policy decision. The (H-)PCF may get the PEI, the OSId, indication of UE capability of reporting URSP rule enforcement to network or the indication of UE support for ANDSP in the UDR using Nudr_DM_Query including DataSet "Policy Data" and Data Subset "UE context policy control data" if the AMF relocates and the PCF changes. In the roaming scenario, the H-PCF may provide the indication of UE support for ANDSP to the V-PCF, if the indication was not present in the Npcf_UEPolicyControl Create request from V-PCF and the H-PCF gets this information from the H-UDR. The (H-)PCF may get the 5G VN group data and 5G VN group membership for each Internal-Group-ID received from the AMF using Nudr_DM_Query (Internal-Group-Id, Subscription Data, 5G VN Group Configuration). The (H-)PCF may store the 5G VN group data and 5G VN group membership for later use for other SUPIs that belong to the same Internal-Group-ID. The (H-)PCF may request notifications from the UDR on changes in the subscription information by invoking Nudr_DM_Subscribe (Policy Data, SUPI, DNN, S-NSSAI, Notification Target Address (+ Notification Correlation Id), Event Reporting Information (continuous reporting), UE context policy control data) service. The (H-)PCF may request notifications from the UDR on changes in the 5G VN group data or 5G VN group membership associated to each of the Internal-Group-Id provided to the PCF by invoking Nudr_DM_Subscribe (Subscription Data, 5G VN Group Configuration, Internal Group ID, Notification Target Address (+ Notification Correlation Id), Event Reporting Information (continuous reporting)) service. The (H-)PCF creates the UE policy container including UE policy information as defined in clause 6.6 of TS 23.503 [20] and in the case of roaming H-PCF provides the UE policy container in the Npcf_UEPolicyControl_UpdateNotify Request. In the non-roaming case, the PCF may subscribe to Analytics from NWDAF as defined in clause 6.1.1.3 of TS 23.503 [20].
7. The V-PCF sends a response to H-PCF using Npcf_UEPolicyControl_UpdateNotify Response.
NOTE 2: Step 6 (and step 7) can be omitted. Then the (H-)PCF creates the UE policy container including UE polices in step 2 (in the case of non-roaming) or step 3 (in the case of roaming). This means that the potential interactions with UDR as in step 6 will have to be executed in step 2 (non-roaming) or step 3 (roaming).
8. The (V-)PCF triggers UE Configuration Update Procedure in clause 4.2.4.3 to sends the UE policy container including UE policy information to the UE. The (V-)PCF checks the size limit as described in clause 6.1.2.2.2 of TS 23.503 [20].
9. If the V-PCF received notification of the reception of the UE Policy container then the V-PCF forwards the notification response of the UE to the H-PCF using Npcf_UEPolicyControl_Update Request.
If the V-PCF is notified by the V-UDR about the Service Specific Information applicable to inbound roamers from the HPLMN of the UE as specified in clause 4.15.6.10, the V-PCF provides the Service Parameters to the H-PCF.
10. The H-PCF sends a response to the V-PCF. If the V-PCF received a UE Policy Container step 8 will follow. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.16.12 UE Policy Association Modification | |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.16.12.1 UE Policy Association Modification initiated by the AMF | |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.16.12.1.1 UE Policy Association Modification initiated by the AMF without AMF relocation | This procedure addresses the scenario where a Policy Control Request Trigger condition is met.
Figure 4.16.12.1.1-1: UE Policy Association Modification initiated by the AMF
This procedure concerns both roaming and non-roaming scenarios.
In the non-roaming case the V-PCF is not involved. In the roaming case, the AMF interacts with the V-PCF and the H-PCF interacts with the V-PCF.
1. When a Policy Control Request Trigger condition is met the AMF updates UE Policy Control Association and provides information on the conditions that have changed to the PCF. The AMF sends a Npcf_UEPolicyControl Update Request with the following information: UE Policy Association ID associated with the SUPI defined in TS 29.525 [58] and the Policy Control Request Trigger met. In roaming scenario, based on operator policies, the AMF may provide to the V-PCF the PCF ID of the selected H-PCF. The V-PCF contacts the H-PCF.
See clause 6.1.2.5 of TS 23.503 [20] and clause 4.2.3.2 of TS 29.525 [58] for more details on Policy Control Request Trigger.
The AMF may indicate to the PCF that the UE supports N3IWF selection based on the slices the UE wishes to use over untrusted non-3GPP access and/or UE support for TNGF selection based on the slices the UE wishes to use over trusted non-3GPP access.
In the roaming case, steps 2 and 3 are executed, otherwise step 4 follows.
2. The V-PCF forwards the information received from AMF in step 1 to the (H-)PCF.
3. The H-PCF replies to the V-PCF. In the non-roaming case, the PCF may subscribe to Analytics from NWDAF as defined in clause 6.1.1.3 of TS 23.503 [20].
4. The (V-) PCF sends a Npcf_UEPolicyControl Update Response to the AMF.
5. The (H-)PCF may create the UE policy container including UE policy information as defined in clause 6.6 of TS 23.503 [20]. In the case of roaming the H-PCF may include the UE policy container in the Npcf_UEPolicyControl_UpdateNotify Request.
6. The (V-)PCF sends a response to H-PCF using Npcf_UEPolicyControl_UpdateNotify Response.
Steps 7, 8 and 9 are the same as steps 8, 9 and 10 of procedure UE Policy Association Establishment in clause 4.16.11. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.16.12.1.2 UE Policy Association Modification with old PCF during AMF relocation | This procedure addresses the scenario where a UE Policy Association Modification with the old PCF during AMF relocation.
Figure 4.16.12.1.2-1: Policy Association Modification with the old PCF during AMF relocation
This procedure addresses both roaming and non-roaming scenarios.
In the non-roaming case the V-PCF is not involved. In the roaming case, the AMF interacts with the V-PCF and the V-PCF interacts with the H-PCF.
1. [Conditional] When the old AMF and the new AMF belong to the same PLMN, the old AMF transfers to the new AMF the UE Policy Association information including policy control request trigger(s) and the PCF ID(s). For the roaming case, the new AMF receives both V-PCF ID and H-PCF ID.
2. Based on local policies, the new AMF decides to re-use the UE policy association for the UE Context with the (V-)PCF and contacts the (V)-PCF identified by the PCF ID received in step 1.
NOTE: The scenario that only the H-PCF is reused by the new AMF but the V-PCF is not reused is not considered in this Release.
3. The new AMF sends Npcf_UEPolicyControl_Update to the (V-)PCF to update the UE policy association with the (V-)PCF. If a Policy Control Request Trigger condition is met, the information matching the trigger condition may also be provided by the new AMF.
In the roaming case, step 4 and 5 are executed, otherwise step 6 follows.
4. The V-PCF forwards the information received from new AMF in step 3 to the (H-)PCF.
5. The H-PCF replies to the V-PCF. In non-roaming case, the PCF may subscribe to Analytics from NWDAF as defined in clause 6.1.1.3 of TS 23.503 [20].
6. The (V-)PCF updates the stored information provided by the old AMF with the information provided by the new AMF. The (V-)PCF sends a Npcf_UEPolicyControl Update Response to the AMF.
7. The (H-)PCF may create the UE policy container including UE policy information as defined in clause 6.6 of TS 23.503 [20]. In the case of roaming the H-PCF may include the UE policy container in the Npcf_UEPolicyControl_UpdateNotify Request.
8. The V-PCF sends a response to H-PCF using Npcf_UEPolicyControl_UpdateNotify Response.
Steps 9, 10 and 11 are the same as steps 8, 9 and 10 of procedure UE Policy Association Establishment in clause 4.16.11. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.16.12.2 UE Policy Association Modification initiated by the PCF | This procedure is used to update UE policy and/or UE policy triggers.
The H-PCF may interact with the CHF in HPLMN to make a decision about UE Policies based on spending limits.
Figure 4.16.12.2-1: UE Policy Association Modification initiated by the PCF
This procedure concerns both roaming and non-roaming scenarios.
In the non-roaming case the V-PCF is not involved and the role of the H-PCF is performed by the PCF. In the roaming case, the H-PCF provides UE policy decision and provides the policy to the AMF via V-PCF.
1a and 1b. If (H-)PCF subscribed to notification of subscriber´s policy data change or 5G VN Group Configuration (5G VN group data, 5G VN group membership) change and a change is detected, the UDR notifies that the subscriber´s policy data of a UE or 5G VN Group Configuration (5G VN group data, 5G VN group membership) has been changed.
The UDR notifies the (H-)PCF of the updated policy control subscription information profile via Nudr_DM_Notify (Notification correlation Id, Policy Data, either UE context policy control data or Policy Set Entry data or both, SUPI), or
The UDR notifies the (H-)PCF of the updated 5G VN Group Configuration (5G VN group data, 5G VN group membership) via Nudr_DM_Notify (Notification correlation Id, 5G VN Group Configuration, Internal-Group-Identifier), or
The (V-)UDR notifies the (V-)PCF of the updated policy control subscription information profile via Nudr_DM_Notify (Notification correlation Id, Policy Data, PolicySetEntry Data. PLMN ID).
The (V-)UDR notifies the (V-)PCF of the updated Service Parameters via Nudr_DM_Notify.
1c and 1d. PCF determines locally that UE policy information needs to be sent to the UE.
1e The (H-)CHF notifies the (H-)PCF about the change of the status of the subscribed policy counters available at the (H-)CHF for that subscriber.
2a and 2b. The PCF makes the policy decision. If the group data is updated, the (H-) PCF checks the UE Policy Associations for those SUPIs within the Internal-Group-Id and may need to perform step 3 to step 9 for each UE Policy Association that needs to be updated with new UE Policies sent to each UE. In the non-roaming case, the PCF may subscribe to Analytics from NWDAF as defined in clause 6.1.1.3 of TS 23.503 [20].
2c and 2d. In the roaming case, the V-PCF may provide the updated Service Parameters received from the V-UDR as specified in clause 4.15.6.10 to the H-PCF using the Npcf_UEPolicyControl_Update Request. The H-PCF sends a response to the V-PCF.
3. The (H-)PCF may create the UE policy container including UE policy information as defined in clause 6.1.2.2.2 of TS 23.503 [20]. In the case of roaming, the H-PCF may send the UE policy container in the Npcf_UEPolicyControl_UpdateNotify Request. The H-PCF may provide updated policy control triggers for the UE policy association. If there is the received Service Parameters from the V-PCF in step 2, the H-PCF may take the Service Parameters obtained from V-PCF to generate URSP rules applicable in the VPLMN as specified in clause 4.15.6.10.
4. The V-PCF sends a response to H-PCF using Npcf_UEPolicyControl_UpdateNotify Response.
5. The (V-)PCF provides the Policy Control Request Trigger parameters in the Npcf_UEPolicyControl_UpdateNotify Request to the AMF. In the case of roaming, the V-PCF may also provide UE policy information to the UE. The V-PCF may also provide updated policy control triggers for the UE policy association to the AMF.
6. The AMF sends a response to (V-)PCF.
Steps 7, 8 and 9 are the same as steps 8, 9 and 10 of procedure UE Policy Association Establishment in clause 4.16.11. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.16.13 UE Policy Association Termination | |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.16.13.1 AMF-initiated UE Policy Association Termination | The following case is considered for UE Policy Association Termination:
1. UE Deregistration from the network when the UE is not registered in another access type.
2. The mobility with change of AMF (e.g. new AMF is in different PLMN or new AMF in the same PLMN).
3. [Optional] 5GS to EPS mobility with N26 if the UE is not connected to the 5GC over a non-3GPP access in the same PLMN.
4. A change of the value of the UE Policy Association indicator received from UDM.
The H-PCF may interact with the H-CHF in HPLMN.
Figure 4.16.13.1-1: AMF-initiated UE Policy Association Termination
This procedure concerns both roaming and non-roaming scenarios.
In the non-roaming case, the V-PCF is not involved and the role of the PCF is performed by the H-PCF. For the roaming scenarios, the V-PCF interacts with the AMF. The V-PCF contacts the H-PCF to request removing UE Policy Association.
1. The AMF decides to terminate the UE Policy Association.
2. The AMF sends the Npcf_UEPolicyControl_Delete service operation including UE Policy Association ID to the (V-)PCF.
3. The (V-)PCF removes the policy context for the UE and replies to the AMF with an Acknowledgement including success or failure. The V-PCF may interact with the H-PCF. The (V-)PCF may unsubscribe to subscriber policy data changes with UDR by Nudr_DM_Unsubscribe (Subscription Correlation Id). The AMF removes the UE Policy Context.
If the PCF has previously registered to the BSF as the PCF that is serving this UE, the PCF shall deregister from the BSF if no AM Policy Association for this UE exists anymore. This is performed by using the Nbsf_Management_Deregister service operation, providing the Binding Identifier that was obtained earlier from the BSF when performing the Nbsf_Management_Register service operation.
Step 4 and Step 5 apply only to the roaming case.
4. The V-PCF sends the Npcf_UEPolicyControl_Delete service operation including UE Policy Association ID to the H-PCF.
5a. The H-PCF removes the policy context for the UE.
Optionally, based on operator policies, as described in clause 6.1.1.4 of TS 23.503 [20], the H-PCF may store the policy counters and their statuses of spending limits information into the H-UDR by invoking Nudr_DM_Update.
The H-PCF may unsubscribe to subscriber policy data changes with H-UDR by Nudr_DM_Unsubscribe (Subscription Correlation Id) for subscriber policy changes. In the non-roaming case, the H-PCF may unsubscribe to analytics from NWDAF.
5b. The H-PCF may invoke the procedure defined in clause 4.16.8 to unsubscribe to policy counter status reporting or to modify the subscription to policy counter status reporting in H-CHF (if remaining Policy association for this subscriber requires policy counter status reporting).
6. The H-PCF sends a Npcf_UEPolicyControl_Delete Response to the V-PCF with an acknowledgement including success or failure. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.16.13.2 PCF-initiated UE Policy Association Termination | Figure 4.16.13.2-1: PCF-initiated UE Policy Association Termination
This procedure concerns both roaming and non-roaming scenarios.
In the non-roaming case, the V-PCF is not involved and the role of the H-PCF is performed by the PCF. For the roaming scenarios, the H-PCF interacts with the V-PCF to request removing Policy Association.
The PCF is subscribed to notification of changes in Data Set "Policy Data" for a UE Policy Association ID.
1. The Policy data is removed, either the Data Set "Policy Data" or the Data Subset "UE context policy control".
2. The UDR sends the Nudr_DM_Notify_Request (Notification correlation Id, Policy Data, SUPI, UE Context Policy Control data, updated data) including the SUPI, the Data Set Identifier, the Data Subset Identifier and the Updated Data including empty "Policy Data" or empty "UE context policy control".
3. The PCF sends the Nudr_DM_Notify_Response to confirm reception and the result to UDR.
4. The PCF may initiate the removal of the UE Policies in the UE by invoking steps 7, 8 and 9 of procedure UE Policy Association Modification initiated by the PCF in clause 4.16.12.2. Alternatively, following the same steps from clause 4.16.12.2 the PCF may decide to update the UE Policies in the UE based on a default profile.
5. The PCF may notify the AMF of the removal of the UE Policy Association via Npcf_UEPolicyControl_UpdateNotify service operation. Alternatively, the PCF may decide to maintain the Policy Association if a default profile is applied, in this case steps 5, 6 and 7 are not executed.
In the non-roaming case, the PCF unsubscribes to analytics from NWDAF if any.
6. The AMF acknowledges the operation.
7. Steps 2-5 in clause 4.16.13.1 AMF-initiated UE Policy Association Termination are performed to remove the UE Policy Association for this UE and the subscription to Policy Control Request Triggers for that UE Policy Association. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.16.14 Management of access and mobility related policy information depending on the application in use | |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.16.14.1 General | The procedure for management of access and mobility related policy information depending on the application in use enables modification of the access and mobility related policy information on detection of the start and stop of an application.
The content of this clause applies to non-roaming and LBO roaming scenario (for any inbound roaming UEs), i.e. to cases where the involved entities (e.g. PCF, SMF and UPF) belong to the serving PLMN. The PCF shall not apply a change of access and mobility related policy information for application traffic detected in PDU Sessions established in Home Routed mode.
If PCF for the UE and PCF for the PDU Session are the same PCF, then steps 3, 5, 6, 9 and 12 in Figure 4.16.14.2-1 are not performed.
If the PCF for the UE and the PCF for the PDU Session are different PCFs, then the PCF for the UE is informed when a SM Policy Association is established or released by either:
- Subscription to the BSF:
= see steps 1, 2, 3, 4, 5a, 11 and 12a in Figure 4.16.14.2.1-1. The BSF notifies when a PCF is registered or deregistered for the PDU Session to a DNN, S-NSSAI.
- see steps 1, 2, 3, 5a and 8 in Figure 4.16.14.2.2-1. The BSF reports the registration of a PCF for the PDU Session when the first SM Policy Association is established and the deregistration of the PCF for the PDU Session when the last SM Policy Association is terminated for a (DNN, S-NSSAI).
- see steps 1, 2, 3, 5a, 11a in Figure 4.16.14.2.2-3. The BSF reports the registration of a PCF for the PDU Session when the first SM Policy Association is established and the deregistration of the PCF for the PDU Session when the last SM Policy Association is terminated for a (DNN, S-NSSAI).
- Request for notification of SM Policy Association establishment or termination and the PCF binding information via AMF and SMF. See steps 1, 4, 5b, 11 and 12b in Figure 4.16.14.2-1, Figure 4.16.14.2-2 and Figure 4.16.14.2-3. The PCF for the PDU Session reports that the SM Policy Association is established as described in clause 4.16.4 and provides the UE address(es). The SM Policy Association Termination notifies the PCF for the UE as described in clause 4.16.6. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.16.14.2 Procedures for management of access and mobility related policy information | |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.16.14.2.1 Management of access and mobility related policy information at start and stop of application traffic | This procedure applies when the AF provides a service coverage area or the indication of high throughput associated with the Application Identifier(s).
Figure 4.16.14.2.1-1: Management of access and mobility related policy information at start and stop of application traffic
1. The AMF establishes an AM Policy Association for retrieving access and mobility related policy information, e.g. RFSP index value, as described in clause 4.16.1.2.
2. If the access and mobility related policy information depends on the application in use, then depending on operator policies in the PCF, the PCF may subscribe to the BSF, then step 3 follows, or provides its PCF binding information with Request for notification of SM Policy Association establishment or termination for a DNN, S-NSSAI to the AMF, then step 5b follows.
3. The PCF for the UE determines that access and mobility related policy information (e.g. RFSP index value) depends on the detection of one or more application(s) in use, the DNN, S-NSSAI used to access each Application Id is configured in the PCF or retrieved from the UDR as part of the Application Data Set, then subscribes to the BSF to be notified when a PCF for the PDU Session for this SUPI is registered in the BSF, by invoking Nbsf_Management_Subscribe (SUPI, list of (DNN, S-NSSAI)(s)). Steps 4 and 5 are repeated for each PCF registered for a PDU Session to a (DNN, S-NSSAI) included in the Nbsf_Management.
4. The SMF establishes a SM Policy Association as described in clause 4.16.4. The allocated UE address/prefix, SUPI, DNN, S-NSSAI and the PCF address is registered in the BSF, as described in clause 6.1.1.2.2 of TS 23.503 [20].
5a. If the PCF for the UE subscribed to the BSF, then the BSF notifies that a PCF for the PDU Session is registered in the BSF, by invoking Nbsf_Management_Notify (DNN, S-NSSAI, UE address(es), PCF address, PCF instance id, PCF Set ID, level of binding). When there are multiple PDU Sessions to the same (DNN, S-NSSAI) the BSF provides multiple notification to the PCF.
5b. If the PCF for the UE sent the Request for notification of SM Policy Association establishment or termination and the PCF binding information to the AMF in step 2, then the PCF for the PDU Sessions sends Npcf_PolicyAuthorization_Notify (EventID set to SM Policy Association established, UE address, PCF address, PCF instance ID, PCF Set ID) to the PCF indicated in the PCF binding information provided by the SMF.
6. The PCF for the UE subscribes to notifications of event "start/stop of application traffic" as defined in clause 6.1.3.18 of TS 23.503 [20], using Npcf_PolicyAuthorization_Subscribe (UE address, EventId, EventFilter set to "list of Application Identifiers") to the PCF for the PDU Session to the DNN, S-NSSAI. The PCF for the PDU Session then generates PCC Rules including the Application Identifier in the SDF template, if there are multiple Application Identifiers included in the Npcf_PolicyAuthorization, the PCF generates PCC Rules for each Application Identifier. The response includes the NotificationCorrelationId.
7. The PCF installs PCC Rules and the Policy Control Request Trigger to detect "start/stop of application traffic" in the SMF.
8. The SMF detects that the Policy Control Request Trigger is met, then reports the start/stop of application traffic to the PCF serving the PDU Session.
9. The PCF for the UE is notified on the start/stop of application traffic by Npcf_PolicyAuthorization_Notify (NotificationCorrelationId, EventId set to "start/stop of application traffic", EventInformation including the ApplicationId). When the reporting of start and stop of a list of Application(s) was requested, the PCF for the PDU Session provides multiple notification to the PCF for the UE.
10. The PCF checks operator policies and then may change access and mobility related policy information (e.g. RFSP index value) based on the reporting of start/stop of application traffic.
11. The SM Policy Association is terminated as described in clause 4.16.6. The allocated UE address/prefix, SUPI, DNN, S-NSSAI and the PCF address are deregistered in the BSF.
12a. If the PCF for the UE subscribed to the BSF, then the BSF notifies that the PCF serving a PDU Session is deregistered in the BSF, by invoking Nbsf_Management_Notify (Binding Identifier for the PDU Session).
12b. If the PCF for the UE sent the Request for notification of SM Policy Association establishment or termination to the AMF in step 1, then the PCF for the PDU Session sends Npcf_PolicyAuthoritation_Notify ((EventID set to SM Policy Association termination, Notification Correlation Id).
NOTE: The PCF for the UE may subscribe to the notifications of newly registered PCF for the PDU Session and subscribe to the "start/stop of application traffic detection" events for multiple applications with different application identifiers. When PCF receives the notifications for multiple applications, the PCF for the UE can determine which access and mobility related policy information to apply based on local configuration and operator policy. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.16.14.2.2 Management of access and mobility related policy information at SM Policy Association establishment and termination with the notification sent by the BSF | Figure 4.16.14.2.2-1: Management of access and mobility related policy information at SM Policy Association establishment and termination with the notification by the BSF
1. The AMF establishes an AM Policy Association for retrieving access and mobility related policy information, e.g. RFSP index value, as described in clause 4.16.1.2.
2. If the access and mobility related policy information depend on the SM Policy Association establishment and termination for a DNN, S-NSSAI combination, then depending on operator policies in the PCF, the PCF may subscribe to BSF and then step 3 follows, or the PCF may provide its PCF binding information to the AMF with the indication to be notified about the PCF for the PDU Session for a DNN, S-NSSAI and then step 4 follows.
3. The PCF for the UE determines that access and mobility related policy information (e.g. RFSP index value) depend on the detection of SM Policy Association establishment associated with the (DNN, S-NSSAI) combinations configured in the PCF or retrieved from the UDR as part of the Application Data Set. The PCF for the UE then subscribes to the BSF to be notified when a PCF for the PDU Session is registered for the first SM Policy Association establishment and the PCF for the PDU Session is deregistered for the last SM Policy Association termination to the same (DNN, S-NSSAI) combination in the BSF, by invoking Nbsf_Management_Subscribe (SUPI, list of (DNN, S-NSSAI)(s), indication of registration/deregistration per (DNN, S-NSSAI)).
4. The SMF establishes a SM Policy Association as described in clause 4.16.4. The allocated UE address/prefix, SUPI, DNN, S-NSSAI and the PCF address are registered in the BSF, as described in clause 6.1.1.2.2 of TS 23.503 [20].
5. If the PCF for the UE subscribed to BSF, then the BSF notifies a PCF registration when the first SM Policy Association corresponding to the (DNN, S-NSSAI) combination is established, by invoking Nbsf_Management_Notify (DNN, S-NSSAI, notification of registration).
6. The PCF checks operator policies and then may change access and mobility related policy information (e.g. RFSP index value) based on the reporting of SM Policy Association establishment.
7. The SM Policy Association is terminated as described in clause 4.16.6 and the allocated UE address/prefix, SUPI, DNN, S-NSSAI and the PCF address are deregistered in the BSF.
8. If the PCF for the UE subscribed to BSF, then BSF notifies of a PCF deregistration when the last SM Policy Association corresponding to the (DNN, S-NSSAI) combination is terminated, by invoking Nbsf_Management_Notify (DNN, S-NSSAI, notification of deregistration). |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.16.15 Negotiations for planned data transfer with QoS requirements | |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.16.15.1 General | The intent of this clause is to specify generic service procedures to enable the AF to negotiate viable time window for the planned application data transfer with specific QoS requirements and operational conditions via the support of the NEF.
The PDTQ policies are defined for a specific ASP and each PDTQ policy includes a recommended time window for the traffic transfer for each of the AF sessions involved.
The Network Performance analytics or DN Performance analytics for NWDAF as described in TS 23.288 [50] will be subscribed by the PCF in order to assist its decision to derive the PDTQ policies.
One or more negotiated PDTQ policies could be provided by PCF to AF via NEF together with the PDTQ Reference ID. If the AF receives more than one PDTQ policies from the PCF, the AF will select one of them and inform the PCF about the selected PDTQ policy which will then be stored in the UDR. The selected PDTQ policy might be renegotiated, i.e. due to the degradation of the network performance. In this case, the PCF may determine a new list of candidate PDTQ policies and notify the AF via NEF. The AF may select one of the new PDTQ polices or not accept any of the PDTQ policies, it then notifies the PCF of the corresponding decision. Prior to the start of the selected time window for the planned data transfer, the AF requests the PCF to set up the AF session with required QoS. The PCF will then determine the appropriate PCC rules according to the AF request. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.16.15.2 Procedures | |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.16.15.2.1 Procedures for negotiation of planned data transfer with QoS requirements | This clause describes the PDTQ procedures to negotiate viable time window for the planned application data transfer via the support of the NEF.
Figure 4.16.15.2.1-1: Negotiation for planned data transfer with QoS requirements
Prior to the transmission of the Application AI/ML data, the AF negotiates with the 5G Core for the PDTQ policies that provide assistance for the application data transfer. The AF discovers its serving NEF, if it has not done so before, by using the mechanism described in clause 6.3.14 of TS 23.501 [2].
1a. The AF invokes the Nnef_PDTQPolicyNegotiation_Create Request (ASP Identifier, Number of UEs, list of Desired time windows, QoS Reference or individual QoS parameters, Alternative Service Requirements (optional), Network Area Information, Request for notification, Application Identifier). The Request for notification is an indication that PDTQ warning notification can be sent to the AF.
NOTE 1: Based on AF's internal logic (policy), the AF may determine the minimum QoS requirements by considering the UEs expected to participate in the Desired time windows, the network input data and the trigger conditions for group application data transfer.
1b-1c. The NEF may authenticate the AF and authorize the PDTQ request from the AF. If the authentication/authorization of the AF's request has failed, the NEF will respond to the AF's request through the Nnef_PDTQPolicyNegotiation_Create Response with a failure result and the following steps are skipped.
The NEF may map the ASP ID into DNN and S-NSSAI to be used in step 2.
NOTE 2: The Application ID provided by the AF and the Application ID provided to NWDAF can be different, and in such a case, a mapping is performed by the PCF.
2. Based on an AF request, the NEF may translate the information provided by the AF (e.g. Network Area Information, etc.) based on the local policy and invokes the Npcf_PDTQPolicyControl_Create (ASP Identifier, Number of UEs, list of Desired time windows, QoS Reference or individual QoS parameters, Alternative Service Requirements (optional), Network Area Information, Request for notification, Application Identifier) with the H-PCF to authorize the creation of the policy regarding the PDTQ. If the PCF was provided with Request for notification, then PCF will send PDTQ warning notification to the AF as specified in clause 4.16.15.2.2 to notify the AF when the network performance or DN Performance in the area of interest reaches the Reporting Threshold set by the PCF based on operator configuration or the PCF determines to update the previously selected PDTQ policy based on the latest periodic reported network performance or DN Performance analytics as described in clause 6.1.2.7 of TS 23.503 [20].
The PCF may be configured to map the ASP identifier to a target DNN and S-NSSAI if the NEF did not provide the DNN, S-NSSAI to the PCF.
3. H-PCF queries the UDR to retrieve all existing PDTQ polices for all the ASPs using Nudr_DM_Query (Policy Data, Planned Data Transfer with QoS requirements) service operation.
4. The UDR provides all the stored PDTQ policies and corresponding related information (e.g. the Number of UEs, the list of Desired time windows) to the H-PCF.
5. Based on information provided by the AF and other available information as described in clause 6.1.2.7 of TS 23.503 [20], the H-PCF requests or subscribes to the NWDAF as defined in clause 6.6.4 or clause 6.14.4 of TS 23.288 [50] to receive the Network Performance analytics or the DN Performance analytics.
When requesting the Network Performance analytics or the DN performance analytics, if "any UE" is used, then the AoI information is used to identify the target gNB(s) for the prediction of the availability of the network resources.
The DNN, S-NSSAI and Application ID may be provided by H-PCF as Analytics Filter Information when requesting or subscribing to the relevant Analytic ID.
6. By referring to the outcome of the analytics report as described in clause 6.1.2.7 of TS 23.503 [20], H-PCF determines one or more PDTQ policies. Each PDTQ policy includes a recommended time window for the traffic transfer for each of the AF sessions for each of the UEs involved.
NOTE 3: The existing PDTQ policies for all ASPs retrieved from the UDR in step 4 can be considered by the PCF when determining PDTQ policies for the requested ASP (e.g. the PCF can avoid selecting time windows that are already allocated to other ASPs).
7. The PCF sends one or more PDTQ policies to NEF in Npcf_PDTQPolicyControl_Create Response including the PDTQ Reference ID.
8. The NEF sends a Nnef_PDTQPolicyNegotiation_Create response to the AF to provide one or more PDTQ policies together with the PDTQ Reference ID. If the NEF received only one PDTQ policy from the PCF, steps 9-12 are not executed and the flow proceeds to step 13. Otherwise, the flow proceeds to step 9.
9. If more than one PDTQ policies were provided to the AF, the AF selects one of the PDTQ policies and notifies NEF for the selected PDTQ policy via Nnef_PDTQPolicyNegotiation_Update request together with the PDTQ Reference ID. The AF stores the PDTQ Reference ID for the future interaction with the PCF.
10-12. The NEF notifies H-PCF about the selected PDTQ policy by the AF. The H-PCF acknowledges NEF. The NEF responds to the AF request with a Nnef_PDTQPolicyNegotiation_Update Response.
13-14. The H-PCF stores the PDTQ Reference ID together with the new PDTQ policy in the UDR by invoking Nudr_DM_Update (PDTQ Reference ID, Policy Data, Planned Data Transfer with QoS requirements). The UDR sends a response to the H-PCF as acknowledgement. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.16.15.2.2 Procedure for PDTQ warning notification | Figure 4.16.15.2.2-1: The procedure for PDTQ warning notification
1. The negotiation for PDTQ policy as described in clause 4.16.15.2.1 is completed. In addition, the PCF has subscribed to analytics on "Network Performance" or "DN Performance" from NWDAF for the area of interest and time window of a PDTQ policy following the procedures and services described in TS 23.288 [50], including a Reporting Threshold in the Analytics Reporting information. The value for Reporting Threshold is set by the PCF based on operator configuration.
2. The PCF is notified with the Network Performance analytics or DN Performance analytics in the area of interest from the NWDAF when the NWDAF determines that the Network Performance or DN Performance reaches the Reporting Threshold as described for the Network Performance analytics or DN Performance analytics in TS 23.288 [50].
3. The H-PCF requests from the UDR the stored PDTQ policies using Nudr_DM_Query (Policy Data, Planned Data Transfer with QoS requirements) service operation.
4. The UDR provides all the PDTQ Policies together with the relevant information received from the AFs (as defined in clause 6.1.2.7 of TS 23.503 [20]) to the H-PCF.
5. The H-PCF identifies the PDTQ Policies affected based on the notification received from NWDAF. For each of them, the H-PCF determines the ASP of which the PDTQ traffic will be influenced by the degradation of network Performance or DN Performance and which requested the H-PCF to send the notification. The PCF then performs the following steps for each of the determined ASPs, i.e. Steps 6 - 11 can occur multiple times (i.e. once per ASP).
6. The PCF decides based on operator policies, whether a new list of candidate PDTQ policies can be calculated for the ASP. If the PCF does not find any new candidate PDTQ policy, the previously negotiated PDTQ policy shall be kept, no interaction with that ASP shall occur and the procedure stops for that PDTQ policy.
NOTE: The PDTQ policies of an ASP which did not request to be notified are kept and no interaction with this ASP occurs.
7. The PCF sends the notification to the NEF by invoking Npcf_PDTQPolicyControl_Notify (PDTQ Reference ID, list of candidate PDTQ policies) service operation.
8. The NEF sends the PDTQ warning notification to the AF by invoking Nnef_PDTQPolicyNegotiation_Notify (PDTQ Reference ID, list of candidate PDTQ policies) service operation.
9. The AF checks the new PDTQ policies included in the candidate list in the PDTQ warning notification.
10. If the AF selects any of the new PDTQ policies, the steps 9-14 from clause 4.16.15.2.1 are executed with the difference that the AF has to respond as well when only one PDTQ policy was provided by the PCF and the PCF removes the no longer valid PDTQ policy from the UDR for the corresponding PDTQ Reference ID.
11. If the AF doesn't select any of the new PDTQ policies, the steps 9-12 from clause 4.16.15.2.1 are executed, with the AF indicating that none of the candidate PDTQ policies is acceptable. In this case, the AF response only includes PDTQ reference ID, but no PDTQ policy and the previously negotiated PDTQ policy shall be kept.
The AF can send a Stop notification by invoking Nnef_PDTQPolicyNegotiation_Update service, when the AF requests not to receive the PDTQ warning notification anymore. Then, the NEF invokes Npcf_PDTQPolicyControl_Update service in order to provide this information for the H-PCF. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.16.16 Awareness of URSP Rule Enforcement | |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.16.16.1 General | Awareness of URSP rule enforcement is specified in clause 6.6.2.4 of TS 23.503 [20].
The content of this clause describes the PCF procedures necessary to realize this functionality. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.16.16.2 Forwarding of URSP Rule Enforcement Information (for non-roaming and HR roaming) | This procedure applies when the PCF serving the PDU session receives URSP rule enforcement information from the SMF and forwards this information to the (H-)PCF serving the UE (see clause 6.1.3.18 of TS 23.503 [20] for non-roaming and HR roaming).
Figure 4.16.16.2-1: Forwarding of URSP Rule Enforcement Information (for non-roaming or HR roaming)
1. The UE Policy Association is established, as described in clause 4.16.11.
2. If the (H-)PCF indicates the UE to send reporting of URSP rule enforcement as described in clause 6.6.2.4 of TS 23.503 [20], then depending on operator policies in the (H-)PCF, the (H-)PCF may subscribe to the BSF, then step 3 follows, or provides its PCF binding information to the AMF in step 1 with Request for notification of SM Policy Association establishment or termination for a UE, then step 5b follows.
3. The (H-)PCF for the UE determines that URSP rules depend on the UE reporting of URSP rule enforcement, it then subscribes to the BSF to be notified when a PCF for the PDU Session for this SUPI is registered in the BSF, by invoking Nbsf_Management_Subscribe (SUPI; DNN). Steps 4 and 5a are repeated for each PCF registered for a PDU Session to a SUPI included in the Nbsf_Management.
4. The (H-)SMF establishes a SM Policy Association as described in clause 4.16.4. The allocated UE address/prefix, SUPI, DNN, S-NSSAI and the PCF address is registered in the BSF, as described in clause 6.1.1.2.2 of TS 23.503 [20]. The SMF may provide the PCF binding information (address(es) of PCF for UE, instance id of PCF for UE) which receives from AMF to the PCF for session during SM Policy Association establishment procedure. If the (H-)SMF has received UE report of URSP rule enforcement via PDU session establishment as described in clause 4.3.2 (step 4), it includes the received traffic information in the SM Policy Association establishment request.
5a. If the (H-)PCF for the UE subscribed to the BSF in step 3, then the BSF notifies that a PCF for the PDU Session is registered in the BSF, by invoking Nbsf_Management_Notify (UE address(es), PCF address, PCF instance id, PCF Set ID, level of binding). When there are multiple PDU Sessions to the same UE the BSF provides multiple notification to the PCF.
5b. If the (H-)PCF for the UE sent Request for notification of SM Policy Association establishment or termination to the AMF in step 1, then the PCF for the PDU Sessions sends Npcf_PolicyAuthorization_Notify (EventID set to SM Policy Association established, UE address, PCF address, PCF instance is, PCF Set ID) to the PCF indicated in the PCF binding information provided by the SMF.
6. The (H-)PCF for the UE subscribes to notifications of event "UE reporting Connection Capabilities from associated URSP rule" as defined in clause 6.1.3.18 of TS 23.503 [20], using Npcf_PolicyAuthorization_Subscribe (EventId set to "UE reporting Connection Capabilities from associated URSP rule", EventFilter set to at least "list of Connection Capabilities") and immediate reporting flag set to the PCF for the PDU Session. The response includes the NotificationCorrelationId and any Connection Capabilities if already available at the PCF for the PDU Session.
7. Void.
8. When the (H-)SMF receives a UE report of URSP rule enforcement via PDU session modification as described in clause 4.3.3 (step 8a), it reports the received traffic information to the PCF serving the PDU Session, by invoking Npcf_SMPolicyControl_Update as defined in clause 6.1.3.5 of TS 23.503 [20] (step 8b).
NOTE: The case when the (H-)SMF receives a UE report of URSP rule enforcement via PDU session establishment is covered by steps 4-6a above and is described in clause 6.6.2.4 of TS 23.503 [20].
9. The (H-)PCF for the UE is notified on the "UE reporting Connection Capabilities from associated URSP rule" by Npcf_PolicyAuthorization_Notify (NotificationCorrelationId, EventId set to "UE reporting Connection Capabilities from associated URSP rule", EventInformation including the Connection Capabilities) as defined in clause 6.1.3.18 of TS 23.503 [20].
10. The (H-)PCF for the UE checks operator policies and then may make policy control decisions based on awareness of URSP rule enforcement as described in clause 6.1.1.5 of TS 23.503 [20].
11. The SM Policy Association is terminated as described in clause 4.16.6. The allocated UE address/prefix, SUPI, DNN, S-NSSAI and the PCF address are deregistered in the BSF.
12a. If the (H-)PCF for the UE subscribed to the BSF, then the BSF notifies that the PCF serving a PDU Session is deregistered in the BSF, by invoking Nbsf_Management_Notify (Binding Identifier for the PDU Session).
12b. If the (H-)PCF for the UE sent the Request for notification of SM Policy Association establishment or termination in step 1, then the PCF for the PDU Session sends Npcf_PolicyAuthoritation_Notify (EventID set to SM Policy Association termination, Notification Correlation Id). |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.16.16.3 Forwarding of URSP Rule Enforcement Information (for LBO roaming) | This procedure applies when the PCF serving the PDU session in VPLMN receives URSP rule enforcement information from the SMF and forwards this information to the V-PCF serving the UE in VPLMN and V-PCF forwards the information to the H-PCF serving the UE in HPLMN.
Figure 4.16.16.3-1: Forwarding of URSP Rule Enforcement Information (for LBO roaming)
1. The UE Policy Association is established among the AMF, V-PCF and H-PCF, as described in clause 4.16.11. During this procedure, if the UE indicated support for URSP Rule enforcement report, the H-PCF for the UE may request to forward the UE reporting Connection Capabilities from an associated URSP rule, the H-PCF sends the PCRT to report the Connection Capabilities of the associated URSP rule to the V-PCF.
2. If the H-PCF for the UE indicates the UE to send reporting of URSP rule enforcement as described in clause 6.6.2.4 of TS 23.503 [20] and H-PCF for the UE has requested to forward the UE reporting Connection Capabilities from an associated URSP rule to the V-PCF as in the step 1, then depending on operator policies in the V-PCF, the V-PCF may subscribe to the BSF in VPLMN, then step 3 follows, or provides its PCF binding information to the AMF in step 1 with the Request for notification of SM Policy Association establishment or termination for a UE, then step 5b follows.
3 to 7. The same as the steps 3 to 7 of Figure 4.16.16.2-1 with replacing PCF with V-PCF. The SMF in this figure is located in VPLMN while the H-PCF for the UE is located in HPLMN.
8. If the UE supports the UE capability of reporting URSP enforcement and sends the indication to the H-PCF for the UE at the step 1, and detects the application matching a URSP rule including the Connection Capabilities, the UE reports the Connection Capabilities to the SMF during the PDU Session Establishment/Modification request to the SMF.
When the SMF receives a UE report of URSP rule enforcement via PDU Session Modification, it reports the received traffic information to the PCF serving the PDU Session, by invoking Npcf_SMPolicyControl_Update as defined in clause 6.1.3.5 of TS 23.503 [20] (step 8b).
NOTE: The case when the (H-)SMF receives a UE report of URSP rule enforcement via PDU session establishment is covered by steps 3-7 above and is described in clause 6.6.2.4 of TS 23.503 [20].
9. The same step as the step 9 of Figure 4.16.16.2-1 with replacing PCF with V-PCF.
10. to 11. The same steps as the steps 11 to 12 of Figure 4.16.16.2-1 with replacing PCF with V-PCF. The SMF in this figure is located in VPLMN.
12. If the V-PCF has received the request to forward the UE reporting Connection Capabilities from an associated URSP rule from the H-PCF in the step 1 and the V-PCF for the UE is either notified on the "UE reporting Connection Capabilities from associated URSP rule" by Npcf_PolicyAuthorization_Notify in step 9 or receives "UE reporting Connection Capabilities from associated URSP rule" by Npcf_PolicyAuthorization_Subscribe response in steps 3-7, the V-PCF reports the received the information from the PCF for the PDU Session to the H-PCF.
13. The (H-)PCF for the UE checks operator policies and then may make policy control decisions based on awareness of URSP rule enforcement as described in clause 6.1.1.5 of TS 23.503 [20], and also the H-PCF may take an appropriate action as described in clause 6.6.2.4 of 23.503 [20]. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.17 Network Function Service Framework Procedure | |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.17.1 NF service Registration | NOTE 1: The term "NF service consumer" in this clause refers to the consumer of the NRF services and should not be confused with the role of the NF (consumer or producer).
Figure 4.17.1-1: NF Service Registration procedure
1. NF service consumer, i. e. an NF instance sends Nnrf_NFManagement_NFRegister Request message to NRF to inform the NRF of its NF profile when the NF service consumer becomes operative for the first time. See clause 5.2.7.2.2 for relevant NF profile parameters
NOTE 2: NF service consumer's NF profile is configured by OAM system.
2. The NRF stores the NF profile of NF service consumer and marks the NF service consumer available.
NOTE 3: Whether the NF profile sent by NF service consumer to NRF needs to be integrity protected by the NF service consumer and verified by the NRF is to be decided by SA3.
3. The NRF acknowledge NF Registration is accepted via Nnrf_NFManagement_NFRegister response. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.17.2 NF service update | Figure 4.17.2-1: NF Service Update procedure
1. NF service consumer i.e. an NF instance sends Nnrf_NFManagement_NFUpdate Request message (the updated NF profile of NF service consumer) to NRF to inform the NRF of its updated NF profile (e.g. with updated capacity) when e.g. triggered after a scaling operation. See clause 5.2.7.2.3 for relevant input and output parameters.
NOTE: The updated NF profile of NF instance are configured by OAM system.
2. The NRF updates the NF profile of NF service consumer.
3. The NRF acknowledge NF Update is accepted via Nnrf_NFManagement_NFUpdate response.
NOTE 4: When the NF service consumer registers to NRF via the SCP, the NF Service registration procedure can also be used by the SCP to derive the relation among NF instances, e.g. whether they belong to a specific NF Set. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.17.3 NF service deregistration | Figure 4.17.3-1: NF Service Deregistration procedure
1. NF service consumer i.e. an NF instance sends Nnrf_NFManagement_NFDeregister Request message to NRF to inform the NRF of its unavailability when e.g. it's about to gracefully shut down or disconnect from the network.
2. The NRF marks the NF service consumer unavailable. NRF may remove the NF profile of NF service consumer according to NF management policy.
3. The NRF acknowledge NF Deregistration is accepted via Nnrf_NFManagement_NFDeregister response. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.17.4 NF/NF service discovery by NF service consumer in the same PLMN | Figure 4.17.4-1: NF/NF service discovery in the same PLMN
1. The NF service consumer intends to discover services available in the network based on service name and target NF type. The NF service consumer invokes Nnrf_NFDiscovery_Request (Expected NF service Name, NF Type of the expected NF instance, NF type of the NF consumer) from an appropriate configured NRF in the same PLMN. The parameter may include optionally producer NF Set ID, NF Service Set ID, SUPI, Data Set Identifier(s), External Group ID (for UDM, UDR discovery), UE's Routing Indicator and Home Network Public Key identifier (for UDM and AUSF discovery), S-NSSAI, NSI ID if available and other service-related parameters. In addition, for AMF discovery, the parameters may include AMF Region ID, AMF Set ID, TAI. The NF service consumer may indicate a preference for target NF location in the Nnrf_NFDiscovery_Request. A complete list of parameters is provided in service definition in clause 5.2.7.3.2.
NOTE 1: The NF service consumer indicates its NF location for preference for target NF location.
NOTE 2: The use of NSI ID within a PLMN depends on the network deployment.
NOTE 3: The need for other service-related parameters depends on the NF type of the expected NF instance(s) and refer to the clause 6.3 " Principles for Network function and Network Function Service discovery and selection" in TS 23.501 [2]. It is up to NF implementation whether one or multiple NF service instances are registered in the NRF.
2. The NRF authorizes the Nnrf_NFDiscovery_Request. Based on the profile of the expected NF/NF service and the type of the NF service consumer, the NRF determines whether the NF service consumer is allowed to discover the expected NF instance(s). If the expected NF instance(s) or NF service instance(s) are deployed in a certain network slice, NRF authorizes the discovery request according to the discovery configuration of the Network Slice, e.g. the expected NF instance(s) are only discoverable by the NF in the same network slice.
3. If allowed, the NRF determines a set of NF instance(s) matching the Nnrf_NFDiscovery_Request and internal policies of the NRF and sends the NF profile(s) of the determined NF instances. For the scenario when NF instance(s) reside in a target PLMN as specified in clause 4.2.3 and clause 6.2.6.1 of TS 23.501 [2], the NRF in HPLMN may further query a NRF in that target PLMN. Each NF profile containing at least the output required parameters (see clause 5.2.7.3.2) to the NF service consumer via Nnrf_NFDiscovery_Request Response message.
NOTE 4: The detailed service operation parameters and the involvement of different NRFs are further described in TS 29.510 [37].
If the NF service consumer provided a preferred target NF location, the NRF shall not limit the set of discovered NF instances or NF service instance(s) to the target NF location, e.g. the NRF may provide NF instance(s) or NF service instance(s) for which location is not the preferred target NF location if no NF instance or NF service instance could be found for the preferred target NF location.
If the target NF is UDR, UDM or AUSF, if SUPI was used as optional input parameter in the request, the NRF shall provide the corresponding UDR, UDM or AUSF instance(s) that matches the optional input SUPI. Otherwise, if SUPI is not provided in the request, the NRF shall return all applicable UDR instance(s) (e.g. based on the Data Set Id, NF type), UDM instance(s) or AUSF instance(s) (e.g. based on NF type) and if applicable, the information of the range of SUPI(s) and/or Data Set Id each UDR instance is supporting.
If the target NF is CHF, a NF Consumer may provide if SUPI, GPSI, optionally CHF group ID or PLMN ID as query parameters in the request, the NRF shall provide the corresponding CHF instance(s) that matches these query parameters. The NRF shall provide the primary CHF instance and the secondary CHF instance pair(s) together, if configured in CHF instance profile. Otherwise, if no filter is provided in the request, the NRF shall return all applicable CHF instance(s) and if applicable, the information of the range of SUPI(s), GPSI(s) or PLMN ID(s) or CHF group ID(s).
4.17.4a NF/NF service discovery by NF service consumer in the same SNPN
The NF/NF service discovery by NF service consumer in the same SNPN follows the same principles as NF/NF service discovery by NF service consumer in the same PLMN, see clause 4.17.4. The following additions apply:
- If the target NF is AUSF or NSSAAF and the Nnrf_NFDiscovery_Request includes a Home Network Identifier (HNI) in the form of a realm and the HNI belongs to a CH with AAA Server or a DCS with AAA Server, the NRF provides the AUSF or NSSAAF in the same SNPN, based on the NF profile as specified in clause 6.2.6.2 of TS 23.501 [2].
- If the target NF is UDM and the Nnrf_NFDiscovery_Request includes a Home Network Identifier (HNI) in the form of a realm and the HNI belongs to a CH with AAA Server, the NRF provides the UDM in the same SNPN, based on the NF profile as specified in clause 6.2.6.2 of TS 23.501 [2]. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.17.5 NF/NF service discovery across PLMNs in the case of discovery made by NF service consumer | In the case that the NF service consumer intends to discover the NF/NF service in home PLMN, the NRF in serving PLMN needs to request "NF Discovery" service from NRF in the home PLMN. The procedure is depicted in the figure below:
Figure 4.17.5-1: NF/NF service discovery across PLMNs
1. The NF service consumer in the serving PLMN invokes Nnrf_NFDiscovery_Request (Expected Service Name, NF type of the expected NF, home PLMN ID, serving PLMN ID, NF type of the NF service consumer) to an appropriate configured NRF in the serving PLMN. The request may also include optionally producer NF Set ID, NF Service Set ID, S-NSSAI, NSI ID if available and other service-related parameters. A complete list of parameters is provided in service definition in clause 5.2.7.3.2.
NOTE 1: The use of NSI ID within a PLMN depends on the network deployment.
2. The NRF in serving PLMN identifies NRF in home PLMN (hNRF) based on the home PLMN ID and it requests "NF Discovery" service from NRF in home PLMN according to the procedure in Figure 4.17.4-1 to get the expected NF profile(s) of the NF instance(s) deployed in the home PLMN. As the NRF in the serving PLMN triggers the "NF Discovery" on behalf of the NF service consumer, the NRF in the serving PLMN shall not replace the information of the service requester NF, i.e. NF consumer ID, in the Discovery Request message it sends to the hNRF.
The hNRF may further query another NRF (e.g. a local NRF within the home PLMN or a NRF in a target PLMN for the scenario where NF instances which reside in that target PLMN can be used for traffic from certain UEs as specified in clause 4.2.4 and clause 6.2.6.1 of TS 23.501 [2]) based on the input information received from NRF of the serving PLMN. The Endpoint Address(es) of the NF Discovery service(s) of this NRF may be configured in the hNRF or may need to be discovered based on the input information. For further information about NRF-NRF interactions, see clauses 5.3.2.2.4 and 5.3.2.2.5 of TS 29.510 [37].
NOTE 2: The detailed service operation parameters and the involvement of different NRFs are further described in TS 29.510 [37].
3. The NRF in serving PLMN provides same as step 3 in clause 4.17.4 applies.
4.17.5a NF/NF service discovery between SNPN and Credentials Holder hosting AUSF/UDM or between SNPN and DCS hosting AUSF/UDM
Figure 4.17.5a-1: NF/NF service discovery across SNPN and Credentials Holder
In the case of a UE accessing SNPN using credentials from a Credentials Holder hosting AUSF/UDM, similar procedure can be used for service discovery across PLMNs as specified in clause 4.17.5 with the difference as below:
- The Serving PLMN is replaced by SNPN and Home PLMN is replaced by CH;
- In step 1:
- the Home PLMN ID in Nnrf_NFDiscovery_Request is replaced by identification for the Credentials Holder, i.e.:
- the realm in the case of Network Specific Identifier based SUCI/SUPI; or
- the MCC and MNC in the case of an IMSI based SUCI/SUPI;
NOTE: When IMSI based SUPI is used for a UE of a CH, the IMSI is assumed to be globally unique and assigned by the owner of a PLMN ID containing MCC and MNC of the IMSI as defined in TS 23.501 [2].
- the Serving PLMN ID is replaced by SNPN ID (i.e. PLMN ID and NID);
- In step 2, the NRF in SNPN identifies NRF in CH based on the identification for the Credentials Holder.
In the case of a UE accessing ON-SNPN using Default UE credentials from a DCS hosting AUSF/UDM, a similar procedure can be used than for service discovery across PLMNs as specified in clause 4.17.5, with the difference as below:
- The Serving PLMN is replaced by SNPN and Home PLMN is replaced by DCS;
- In step 1:
- the Home PLMN ID in Nnrf_NFDiscovery_Request is replaced by identification for the DCS, i.e.:
- the realm in the case of Network Specific Identifier based SUCI/SUPI;
- the Serving PLMN ID is replaced by SNPN ID (i.e. PLMN ID and NID);
- In step 2, the NRF in SNPN identifies NRF in DCS based on the identification for the DCS. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.17.6 SMF Provisioning of available UPFs using the NRF | |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.17.6.1 General | This clause describes the provisioning of available UPFs in SMF using the NRF as documented in clause 6.3.3 of TS 23.501 [2].
This optional node-level step takes place prior to selecting the UPF for PDU Sessions and may be followed by N4 Node Level procedures defined in clause 4.4.3 where the UPF and the SMF exchange information such as the support of optional functionalities and capabilities.
As an option, UPF(s) may register in the NRF. This registration phase uses the Nnrf_NFManagement_NFRegister operation and hence does not use N4.
For the purpose of SMF provisioning of available UPFs, the SMF uses the Nnrf_NFManagement_NFStatusSubscribe, Nnrf_NFManagement_NFStatusNotify and Nnrf_NFDiscovery services to learn about available UPFs.
NOTE 1: The protocol used by UPF to interact with NRF is described in TS 29.510 [37]
UPFs may be associated with UPF Provisioning Information in the NRF. The UPF Provisioning Information consists of:
- a list of (S-NSSAI, DNN);
- UE IPv4 Address Ranges and/or IPv6 Prefix Range(s) per (S-NSSAI, DNN); and
NOTE 2: The above information can be used by the SMF for UPF selection when static IP address/prefix allocation is required for a UE.
- a SMF Area Identity the UPF can serve. The SMF Area Identity allows limiting the SMF provisioning of UPF(s) using NRF to those UPF(s) associated with a certain SMF Area Identity. This can e.g. be used if an SMF is only allowed to control UPF(s) configured in NRF as belonging to a certain SMF Area Identity.
- the supported ATSSS steering functionality, i.e. whether MPTCP functionality or ATSSS-LL functionality or MPQUIC-UDP functionality or MPQUIC-IP functionality or MPQUIC-E functionality, or any combination of them is supported.
- the supported UPF event exposure service and supported Event IDs, e.g. local notification of QoS Monitoring to AF or e.g. events for data collection to NWDAF by Nupf_EventExposure_Notify.
- the supported functionality associated with high data rate low latency services, eXtended Reality (XR) and interactive media services, specified in clause 5.37 of TS 23.501 [2] (for example, ECN marking for L4S, specified in clause 5.37.3 of TS 23.501 [2], PDU Set Marking, specified in clause 5.37.5 of TS 23.501 [2], UE power saving management, specified in clause 5.37.8 of TS 23.501 [2], traffic identification and differentiated QoS Flow mapping for media flows multiplexed into a single UDP/IP traffic flow, specified in clause 5.37.11 of TS 23.501 [2], MoQ relay support, specified in clause 5.37.9.2 of TS 23.501 [2]).
- the supported operator configurable UPF capabilities as described in clause 5.8.2.21 of TS 23.501 [2].
- the support of NAT information exposure functionality (see clause 6.2.3 of TS 23.501 [2]).
- the support of IP or MAC filter-based packet detection functionality (see clause 6.2.3 of TS 23.501 [2]).
- the supported N6 delay measurement protocol. This can be used by SMF to determine candidate UPF(s) to perform N6 delay measurements as defined in clause 6.2 of TS 23.548 [74].
- the support of handling of Payload Headers functionality as defined in clause 5.6.17 and clause 5.8.2.22 in TS 23.501 [2].
The SMF Area Identity and UE IPv4 Address Ranges and/or IPv6 Prefix Range(s) are optional in the UPF Provisioning Information. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.17.6.2 SMF provisioning of UPF instances using NRF | This procedure applies when a SMF wants to get informed about UPFs available in the network and supporting a list of parameters.
Figure 4.17.6.2-1: SMF provisioning of UPF instances using NRF procedure
The following takes place when an SMF expects to be informed of UPFs available in the network:
1 The SMF issues a Nnrf_NFManagement_NFStatusSubscribe Service Operation providing the target UPF Provisioning Information it is interested in.
2 The NRF issues Nnrf_NFManagement_NFStatusNotify with the list of all UPFs that currently meet the SMF subscription. This notification indicates the subset of the target UPF Provisioning Information that is supported by each UPF.
The following takes place when a new UPF instance is deployed:
3 At any time a new UPF instance is deployed.
4 The UPF instance is configured with the NRF identity to contact for registration and with its UPF Provisioning Information. An UPF is not required to understand the UPF Provisioning Information beyond usage of this information to register in step 5.
5 The UPF instance issues an Nnrf_NFManagement_NFRegister Request operation providing its NF type, the FQDN or IP address of its N4 interface and the UPF Provisioning Information configured in step 4.
6. Alternatively (to steps 4 and 5) OAM registers the UPF on the NRF indicating the same UPF Provisioning Information as provided in step 5. This configuration mechanism is out of scope of this specification.
7. Based on the subscription in step 1, the NRF issues Nnrf_NFManagement_NFStatusNotify to all SMFs with a subscription matching the UPF Provisioning Information of the new UPF |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.17.7 NF/NF service status subscribe/notify in the same PLMN | Figure 4.17.7-1: NF/NF service status subscribe/notify in the same PLMN
1. The NF service consumer subscribes to be notified of newly registered/updated/deregistered NF instances along with its NF services. The NF service consumer invokes Nnrf_NFManagement_NFStatusSubscribe Request from an appropriate configured NRF in the same PLMN.
2. The NRF authorizes the Nnrf_NFManagement_NFStatusSubscribe Request. Based on the profile of the expected NF/NF service and the type of the NF service consumer, the NRF determines whether the NF service consumer is allowed to subscribe to the status of the target NF instance(s) or NF service instance(s).
3. If allowed, the NRF acknowledges the execution of Nnrf_NFManagement_NFStatusSubscribe Request.
4. NRF notifies about newly registered/updated/deregistered NF instances along with its NF services to the subscribed NF service consumer.
NOTE 1: The NF service consumer unsubscribes to receive NF status notifications by invoking Nnrf_NFManagement_NFStatusUnSubscribe service operation.
NOTE 2: When the NF or NF service instance becomes unavailable, the NRF invokes Nnrf_NFManagement_NFStatusNotify service to notify the NF service consumer based on the subscription. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.17.8 NF/NF service status subscribe/notify across PLMNs | In the case that the NF service consumer intends to subscribe to the status of NF/NF service instance(s) in home PLMN, the NRF in serving PLMN needs to request "NF status subscribe" service from NRF in the home PLMN. The notification is sent from the NRF in the home PLMN to the NF service consumer in the serving PLMN without the involvement of the NRF in the serving PLMN. The procedure is depicted in the figure below:
Figure 4.17.8-1: NF/NF service status subscribe/notify across PLMNs
NOTE 1: The NRF in the home PLMN communicates with the NRF and the NF consumer in the serving PLMN via the SEPPs in the respective PLMNs. For the sake of clarity, SEPPs are not depicted in the flow.
1. The NF service consumer in the serving PLMN invokes Nnrf_NFManagement_NFStatusSubscribe Request from an appropriate configured NRF in the serving PLMN.
2. The NRF in serving PLMN identifies NRF in home PLMN (hNRF) based on the home PLMN ID and it requests Nnrf_NFManagement_NFStatusSubscribe service from NRF in home PLMN. As the NRF in the serving PLMN triggers the Nnrf_NFManagement_NFStatusSubscribe service on behalf of the NF service consumer, the NRF in the serving PLMN shall not replace the information of the service requester NF, i.e. NF consumer ID, in the status subscribe Request message it sends to the hNRF.
3. The NRF in serving PLMN acknowledges the execution of Nnrf_NFManagement_NFStatusSubscribe Request to the NF consumer in the serving PLMN.
4. NRF in the home PLMN notifies about newly registered/updated/deregistered NF instances along with its NF services to the subscribed NF service consumer in the serving PLMN.
NOTE 2: The NF service consumer unsubscribes to receive NF status notifications by invoking Nnrf_NFManagement_NFStatusUnSubscribe service operation.
NOTE 3: When the NF or NF service instance becomes unavailable, the NRF in the home PLMN invokes Nnrf_NFManagement_NFStatusNotify service to notify the NF service consumer in the serving PLMN based on the subscription. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.17.9 Delegated service discovery when NF service consumer and NF service producer are in same PLMN | Figure 4.17.9-1: Delegated NF service discovery when NF service consumer and NF service producer are in same PLMN
1. The NF service consumer intends to communicate with an NF service producer. The NF service consumer sends the service request to an SCP. The request may include discovery and selection parameters necessary to discover and select a NF service producer instance. The discovery and selection parameters are included in the request by the NF service consumer in a way that the SCP does not need to parse the request body.
2. The SCP may perform discovery upon the request either by interacting with an NRF using Nnrf_NFDiscovery service NRF or may use information collected during the previous interactions with an NRF (by the Nnrf_NFDiscovery service or Nnrf_NFManagement_NFStatusNotify service operation). The SCP together with the NRF authorizes the request. The SCP may subscribe at the NWDAF for analytics related to abnormal network behaviour/signalling storm and then obtain related information from the NWDAF as specified in TS 23.288 [50]. This subscription and related notifications may already have occurred before step 1 and the SCP may cache such information. The SCP selects the target NF service producer and may take the analytics information obtained from the NWDAF into consideration for that selection.
The SCP can reject request targeting NF service producers that may suffer a signalling storm or cause signalling storm with appropriate error information to enable NF service consumers to take mitigation actions, and the SCP can also updates its profile at the NRF to indicate that certain NF sets or SCP domains are no longer served by the SCP.
NOTE 1: If the discovery and selection parameters in the request include a UE identity, e.g. SUPI or IMPI/IMPU, the SCP can resolve the requested NF's Group ID corresponding to the UE identity and then invoke the Nnrf_NFDiscovery service, as defined in clause 6.3.1 of TS 23.501 [2].
NOTE 2: Rejecting requests can lead to service failures if the NF service consumer is not able to perform appropriate mitigation actions and thus needs to be performed with caution.
3. If the NF service consumer is authorized to communicate with the NF service producer, the SCP forwards the request to the selected NF service producer according to the configuration of the Network Slice, e.g. the expected NF instances are only reachable by NFs in the same network slice.
Editor's note: If is FFS whether the SCP may use overload control defined in TS 29.500 [17] due to that the NF service consumer may suffer or cause a signalling storm, to enable the NF service producer to take mitigation actions.
4. The NF service producer sends a response to the SCP. If the request in step 3 creates a resource in the NF service producer, such as depicted in Figure 4.17.9-1, the NF service producer responds with resource information identifying the created resource.
The SCP may use overload control defined in TS 29.500 [17] due to that the NF service producer may suffer or cause a signalling storm, to enable the NF service consumer to take mitigation actions.
5. The SCP routes the response to the NF service consumer.
If the NF service consumer receives a resource address, it uses it for subsequent requests regarding the concerned resource. Otherwise, the procedure ends here.
6. On a subsequent operation on the created resource, the NF service consumer addresses the resource via the resource address returned by the NF service producer at step 4.
7. The SCP resolves the NF service producer address and selects a target NF service producer instance. The SCP then routes the request to the selected NF service producer instance. See the clause 6.3.1.0 of TS 23.501 [2] for the details of selection of a target NF service producer instance by SCP.
8. The SCP delivers the request to the NF service producer.
9. The NF service producer sends a response to the SCP. The NF service producer may respond with an updated resource information different to the one received in the previous response.
10. The SCP sends a response to the NF service consumer. If the resource information was updated, the NF service consumer uses the received resource information for subsequent operations (requests) on the resource.
NOTE 2: In the similar manner of handling the resource information, a binding indication may be also provided by the NF service producer and used for the subsequent requests of the NF service consumer. See more details in clause 4.17.12. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.17.10 Delegated service discovery when NF service consumer and NF service producer are in different PLMNs without NF selection at target PLMN | Figure 4.17.10-1: Delegated NF service discovery when NF service consumer and NF service producer are in different PLMNs without NF selection at target PLMN
1. The NF service consumer intends to communicate with an NF service producer. The NF service consumer sends the request to an SCP. The request includes at least the source PLMN ID and the target PLMN ID in the discovery and selection parameters necessary for the SCP to discover and select a NF service producer instance. The discovery and selection parameters are included in the request by the NF service consumer in a way that the SCP does not need to parse the request body.
2. The SCP recognises that the request is for a NF service producer in another PLMN. SCP interacts with NRF using the Nnrf_NFDiscovery service.
3. NRF in PLMN-1 and NRF in PLMN 2 interact using the Nnrf_NFDiscovery service. See step 2 in clause 4.17.5.
4. SCP gets Nnrf_NFDiscovery service response with NF profile(s).
5. SCP selects a NF service producer instance in PLMN-2.
6. SCP forwards the request to the selected NF service producer instance in PLMN-2.
Alternatively, SCP may send the discovery request directly to the NRF in PLMN-2, if it has the relevant NRF address and is authorized by the NRF in PLMN-2. Thus step 2 goes from SCP to NRF in PLMN-2 and step 4 goes from NRF in PLMN-2 to SCP and step 3 is omitted.
4.17.10a Indirect Communication with possible delegated service discovery when NF service consumer and NF service producer are in different PLMNs with possible NF selection at target PLMN
This flow applies if NF service consumer and NF service producer are in different PLMNs and either indirect communication without delegated discovery" (Model C in Annex E of TS 23.501 [2]) or indirect communication with delegated discovery" (Model D in Annex E of TS 23.501 [2]) is used.
Figure 4.17.10a-1: Delegated NF service discovery when NF service consumer and NF service producer are in different PLMNs with possible NF selection at target PLMN
0. For indirect communication without delegated discovery (Model C in Annex E of TS 23.501 [2]), the NF-service consumer retrieves NF profiles as shown in Figure 4.17.5-1 and selects either an NF producer instance or an NF instance set.
NOTE 1: In this flow it is assumed that the NF service consumer is not updated to support the "indirect communication without delegated discovery with NF selection at target domain" feature and/or the "indirect communication with delegated discovery with NF selection at target domain" feature.
1. The NF service consumer intends to communicate with an NF service producer. The NF service consumer sends the request to an SCP. The request includes at least the source PLMN ID and the target PLMN ID in the discovery (for Model C and Model D in Annex E of TS 23.501 [2]) and selection parameters necessary for the SCP to discover and select a NF service producer instance. The discovery and selection parameters are included in the request by the NF service consumer in a way that the SCP does not need to parse the request body. For indirect communication without delegated discovery (Model C in Annex E of TS 23.501 [2]), see also step 1 of Figure 4.17.11-1.
If a NF instance was selected by the NF consumer in step 0, steps 2 to 4 are optional.
2. The SCP recognises that the request is for a NF service producer in another PLMN. SCP interacts with NRF using the Nnrf_NFDiscovery service. The SCP may include an indication of "support of indirect communication without delegated discovery with NF selection at target domain feature" (Model C in Annex E of TS 23.501 [2]) and/or an indication of "support of indirect communication with delegated discovery with NF selection at target domain feature" (Model D in Annex E of TS 23.501 [2]).
3. NRF in PLMN-1 and NRF in PLMN 2 interact using the Nnrf_NFDiscovery service. See step 2 in clause 4.17.5. If the SCP provided an indication of "support of indirect communication with delegated discovery with NF selection at target domain feature" and/or of "support of indirect communication without delegated discovery with NF selection at target domain feature" in step 2 and the NRF in PLMN-1 supports those features, the NRF in PLMN-1 includes an indication of support of those features.
Based on operator's policy and the received indication of support of related features, the NRF in PLMN-2 provides an NF discovery response that contains one of:
- Either NF profiles matching parameters provided in the NnrfDiscovery request; or
- If an indication of "support of indirect communication with delegated discovery with NF selection at target domain feature" was received and that option is preferred by NRF in PLMN-2, no candidate NF profiles but the indication that "indirect communication with delegated discovery with NF selection at target domain is requested",. optionally an indication that the reply applies to all NF types (otherwise the indication only relates to the NF type requested in the Nnrf_NFDiscovery request), and optionally the address of an SCP in PLMN2 where to send the request.
- If an indication of "support of indirect communication without delegated discovery with NF selection at target domain feature" was received and that option is preferred by NRF in PLMN-2, candidate NF profiles and the indication that "indirect communication without delegated discovery with NF selection at target domain is requested", optionally an indication that the reply applies to all NF types (otherwise the indication only relates to the NF type requested in the Nnrf_NFDiscovery request), and optionally the address of an SCP in PLMN2 where to send the request.
NOTE 2 For indirect communication without delegated discovery with NF selection at target PLMN, when the request indicates the NF set, the selection of the target NF instance in the set is delegated to the SCP of the target domain. This is also possible for follow-up requests if suitable binding information is received, e.g. NF instance reselection at the target PLMN.
The NRF in PLMN-1 may cache the response and use it to answer subsequent Nnrf_NFDiscovery without interactions with the NRF in PLMN-2.
NOTE 3: The cached response can be applied for the entire PLMN-2 and it can be assumed that it it does not depend on which NRF in PLMN-2 provided it.
NOTE 4: The NRF in PLMN-1 can also interact with the NRFs in PLMN-2 already before receiving related discovery requests to inquire the support of indirect communication by PLMN-2, cache the received information, and use it to answer subsequent discovery requests.
If the SCP provided an indication of "support of indirect communication with delegated discovery with NF selection at target domain feature", based on operator's policy and configuration, the NRF in the PLMN-1 may also determine without interaction with the NRF in the PLMN-2 that indirect communication with delegated discovery with NF selection at target domain is requested for that remote PLMN, and the interaction with the NRF in PLMN-2 and step 3 does not apply. The NRF in PLMN-1 may then provide a configured address of an SCP in PLMN2 in the Nnrf_NFDiscovery service response (step 4).
4. The NRF in PLMN-1 sends an Nnrf_NFDiscovery service response with parameters as described in step 3 to the SCP in PLMN-1. The SCP may cache the response.
Steps 5 and 6 apply if steps 2 to 4 were not executed or the Nnrf_NFDiscovery service response in step 4 contained NF profiles and no indication that "indirect communication with delegated discovery with NF selection at target domain is requested" and no indication that "indirect communication without delegated discovery with NF selection at target domain is requested".
5. If a NF instance was not selected by the NF consumer, SCP in PLMN-1 selects a NF service producer instance in PLMN-2. Otherwise if this is allowed by binding information, the SCP in PLMN-1 may also select a NF service producer instance in PLMN-2
6. SCP in PLMN-1 forwards the request to the selected NF service producer instance in PLMN-2.
Steps 7 to 10 apply if the Nnrf_NFDiscovery service response in step 4 contained the indication that "indirect communication with delegated discovery with NF selection at target domain is requested" and/or the indication that "indirect communication without delegated discovery with NF selection at target domain is requested".
7. If an indication that "indirect communication without delegated discovery with NF selection at target domain is requested" was received but an NF instance or NF set was not yet selected (because the NF consumer applied model D) the SCP shall select an NF producer instance or a NF set (where the SCP in target network need to do the NF instance selection).
If an indication that "indirect communication with delegated discovery with NF selection at target domain is requested" and/or the indication that "indirect communication without delegated discovery with NF selection at target domain is requested" was received, SCP in PLMN-1 forwards the request with discovery and selection parameters to PLMN-2.
8. Unless the SCP in PLMN-2 has appropriate cached information, it interacts with NRF in PLMN-2 using the Nnrf_NFDiscovery service. Candidate NF profiles are returned.
9. If a NF instance was not selected, SCP in PLMN-2 selects a NF service producer instance in PLMN-2. Otherwise if this is allowed by binding information, the SCP in PLMN-2 may also reselect a NF service producer instance.
10. SCP in PLMN-2 forwards the request to the selected NF service producer instance in PLMN-2. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.17.11 Indirect Communication without delegated discovery Procedure | This clause provides the call flow for indirect communication model without delegated discovery.
Figure 4.17.11-1: Procedure for Indirect Communication without delegated discovery
The NF/NF service discovery procedure is defined in clauses 4.17.4 and 4.17.5. In a successful discovery the NF service consumer gets the NF profile(s) matching the search criteria provided in the Nnrf_NFDiscovery_Request message.
1. When the NF Service Consumer needs to send a Service Request and has obtained an endpoint address for the appropriate resources of the NF service producer from the reply to a previous service operation, the NF Service Consumer should indicate that endpoint address as target for the Service Request. Otherwise, if the NF Service Consumer has stored results from the Discovery Procedure, the NF Service Consumer selects an appropriate NF Producer / NF Service Producer instance from the list of NF profiles provided by the NRF. The NF Service Consumer considers the NF and NF service parameters (e.g. TAI, S-NSSAI, locality, priority etc) in the NF profiles. The NF Service consumer requests service from the NF Service producer by sending a service request message to the NF service producer via the SCP and the NF Service Consumer may provide a Routing Binding Indication with the same contents as the previously received Binding Indication.
2. If the Routing Binding Indication is provided by the NF Service Consumer, SCP (re-)selects as specified in Table 6.3.1.0‑1 of TS 23.501 [2] and routes the service request to target accordingly. If the Routing Binding Indication is not provided by the NF Service Consumer, then the SCP routes the service request based on routing information available.
3. The NF Service Producer responds via SCP.
4. SCP forwards the response. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.17.12 Binding between NF service consumer and NF service producer | |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.17.12.1 General | This clause describes the procedures to establish binding between the NF service consumer and producer.
Direct Communication or Indirect Communication procedures may be used between the Consumer and Producer. In the case of Indirect Communication, an SCP is located between the Consumer and Producer. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.17.12.2 Binding created as part of service response | When the NF service consumer communicates with the NF service producer, the producer may return a binding indication to the consumer. The consumer stores the received binding indication and uses it for the subsequent requests concerning the data context.
Figure 4.17.12.2-1: Binding created as part of service response
1. If Direct Communication is used, the NF service consumer selects the NF service producer and sends the request to the selected NF service producer. If Indirect Communication without delegated discovery is used, the NF service consumer selects the NF service producer set or instance and sends the request to the selected NF service producer via the SCP; if the NF service consumer only selects the NF service producer set, it provides the necessary selection parameters and the SCP selects the NF service producer instance. If Indirect Communication with delegated discovery is used, the NF service consumer sends the request to the SCP and provides within the service request to the SCP the discovery and selection parameters necessary to discover and select a NF service producer.
2. The NF service producer sends a response to the NF service consumer. In the response the NF service producer may include a binding indication. If the NF service consumer receives a resource information and binding indication as specified in Table 6.3.1.0-1 of TS 23.501 [2], it uses them for subsequent requests regarding the concerned resource. Otherwise, the procedure ends here.
3. The NF service consumer uses the binding indication and resource information received in the previous step for subsequent requests regarding the concerned resource. If indirect communication with delegated discovery is used, the NF service consumer includes a Routing Binding Indication with the same contents as the received Binding Indication. If indirect communication without delegated discovery is used, the NF service consumer also includes the Routing Binding Indication with the same contents as the received Binding Indication unless the NF service consumer performs a reselection. The SCP shall route the service request using the Routing Binding Indication and resource information sent from the NF service consumer.
4. The NF service producer sends a response to the consumer. The NF service producer may respond with an updated binding indication, different to the one received in the previous response. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.17.12.3 Binding created as part of service request | If the NF service consumer can also be as a NF service producer for later communication from the contacted producer, a service request sent to the producer may include binding indication.
NOTE: This clause only applies to an AMF, V-SMF or I-SMF as NF service consumer sending requests to an SMF and to an AMF as NF service consumer sending requests to an I-SMF or V-SMF, in step 1 unless further usage has been defined in stage 3. Implicit subscriptions are not described in this clause.
Figure 4.17.12.3-1: Binding created as part of service request
1. Instance A, as an NF service consumer sends a service request using either Direct Communication or Indirect communication via SCP and Instance B is selected as NF service producer. If Instance A can also be NF service producer for later communication for the concerned data context, it may include binding indication referring to NF service instance, NF service set, NF instance or NF Set as specified in Table 6.3.1.0-1 of TS 23.501 [2] in the request sent to the NF service producer; the binding indication shall be associated with an applicability indicating "other service" and include the service name. In this case, if indirect communication is used, the SCP sends to the Instance B the service request including the binding indication.
2. Instance B as the NF service producer sends a response to the NF service consumer.
3. When Instance B as NF service consumer needs to invoke the service provided by Instance A, Instance B sends a request using the binding indication received in step 1 as described in Steps 3-4 in Figure 4.17.12.2-1 with the following difference:
- Based on the received binding indication, if delegated discovery is not used, the Instance B may need to discover the corresponding endpoint address of the Instance A. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.17.12.4 Binding for subscription requests | Binding for notifications can be created as part of an explicit or implicit subscription request. In this case, illustrated in Figure 4.17.12.4-1, the subscription request may include a Binding Indication 1 referring to NF service instance, NF service Set, NF instance or NF Set and additionally includes a service name of the NF service consumer as specified in Table 6.3.1.0-1 of TS 23.501 [2]. The NF Service Set ID, NF service instance ID and service name relate to the service of a NF service consumer that will handle the notification.
For direct communication, the NF service producer selects the target for the related notifications using the notification endpoint received in the subscription request. If the notification endpoint included in the subscription is not reachable, the Binding Indication received is used to discover an alternative notification endpoint, as specified in Table 6.3.1.0-1 of TS 23.501 [2].
For indirect communication, the NF service producer includes the notification endpoint received in the subscription and may include a Routing Binding Indication with the same contents as the received Binding Indication. If the notification endpoint included in the subscription is not reachable, the SCP selects the target for the related notifications using the received Routing Binding Indication as specified in Table 6.3.1.0-1 of TS 23.501 [2].
If the Binding Indication for Notifications needs to be updated, the NF service consumer may initiate a new Subscription request to the NF service producer with an updated Binding Indication or may include the Binding Indication in the acknowledgment of a Notification. A Subscription request may also contain updated Notification Correlation ID and Notification Target Address.
Binding for the subscription resource at the NF service producer can also be created: The Subscription Response message may contain a Binding Indication 2 referring to NF service instance, NF instance or NF Set of the NF service producer.
For direct communication, the NF service consumer selects the target for the related request to the producer, such as the request to update the subscription shown in Figure 4.17.12.4-1, using the received Binding Indication 2 as specified in Table 6.3.1.0-1 of TS 23.501 [2].
For indirect communication with delegated discovery, the NF service consumer includes a Routing Binding Indication with the same contents as the received Binding Indication 2. For indirect communication without delegated discovery, the NF service consumer also includes the Routing Binding Indication with the same contents as the received Binding Indication 2 unless it performs a reselection. The SCP selects the target for the related request using the received Routing Binding Indication 2 as specified in Table 6.3.1.0-1 of TS 23.501 [2].
If the Binding Indication for Subscription needs to be updated, the NF service producer may provide an updated binding indication in a notification request to the NF service consumer or in the response to a subsequent subscription update request from the NF service consumer.
Figure 4.17.12.4-1: Binding in a subscription request
Figure 4.17.12.4-2: Binding during subscription via another network function
An NF service consumer may subscribe via another network function. For example, NF_A may subscribe to NF_B on behalf of NF_C. NF_A additionally subscribe to subscription related events. In this case, both the binding indication from NF_C and NF_A are provided to the NF service producer NF_B. The Binding Indication for notifications to subscription related events shall be associated with an applicability indicating "subscription events".
The NF_C's binding indication is used for reselection of a notification endpoint, which is used for event notification. The NF_A's binding indication is used for reselection of a notification endpoint, which is used for subscription change event notification. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.17.13 NRF bootstrapping procedure | Figure 4.17.13-1: Bootstrapping procedure
1. NF service consumer (e.g. v-NRF) sends a Nnrf_Bootstrapping_Get request to the configured address of the Bootstrapping Service instance.
2. NRF responds with all the Service Instances of the NRF and their endpoint addresses. This also contains if the NRF is part of an NF Set. |
fe7d56f8e2b5a29b90140ea988c1e8a1 | 23.502 | 4.18 Procedures for Management of PFDs |
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