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Content for  TS 23.503  Word version:  17.5.0

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6.1.3.6  Policy controlWord‑p. 59

QoS control refers to the authorization and enforcement of the maximum QoS that is authorized for a service data flow, for a QoS Flow or for the PDU Session. A service data flow may be either of IP type or of Ethernet type. PDU Sessions may be of IP type or Ethernet type or unstructured.
The PCF, in a dynamic PCC Rule, associates a service data flow template to an authorized QoS that is provided in a PCC Rule to the SMF. The PCF may also activate a pre-defined PCC Rule that contains that association.
The authorized QoS for a service data flow template shall include a 5QI and the ARP. For a 5QI of GBR or Delay-critical GBR resource type, the authorized QoS shall also include the MBR, GBR and may include the QoS Notification Control parameter (for notifications when authorized GFBR can no longer ( or can again) be fulfilled). For 5QI of Non-GBR resource type, the authorized QoS may include the MBR and the Reflective QoS Control parameter. The 5QI value can be standardized (i.e. referring to QoS characteristics as defined in clause 5.7.3 of TS 23.501), pre-configured (i.e. referring to QoS characteristics configured in the RAN) or dynamically assigned (i.e. referring to QoS characteristics provided by the PCF as Explicitly signalled QoS Characteristics in the PDU Session related policy information described in clause 6.4).
QoS control also refers to the authorization and enforcement of the Session-AMBR and default 5QI/ARP combination. The PCF may provide the Authorized Session-AMBR and the Authorized default 5QI and ARP combination as part of the PDU Session information for the PDU Session to the SMF. The Authorized Session-AMBR and Authorized default 5QI/ARP values takes precedence over other values locally configured or received at the SMF.
In home routed roaming, the H-SMF may provide the QoS constraints received from the VPLMN (defined in clause 4.3.2.2.2 of TS 23.502) to the H-PCF. The H-PCF ensures that the Authorized Session-AMBR value does not exceed the Session-AMBR value provided by the VPLMN and the Authorized default 5QI/ARP contains a 5QI and ARP value supported by the VPLMN. If no QoS constraints are provided the H-PCF considers that no QoS constraints apply unless operator policies define any. The PCF shall also consider the QoS constraints for the setting of the Subsequent Authorized default 5QI/ARP and Subsequent Authorized Session-AMBR.
For policy control, the AF interacts with the PCF and the PCF interacts with the SMF as instructed by the AF. For certain events related to policy control, the AF shall be able to give instructions to the PCF to act on its own, i.e. based on the service information currently available. The following events are subject to instructions from the AF:
  • The authorization of the service based on incomplete service information;
  • The immediate authorization of the service;
  • The gate control (i.e. whether there is a common gate handling per AF session or an individual gate handling per AF session component required);
  • The forwarding of QoS Flow level information or events (see clause 6.1.3.18).
The UE and the AF shall provide all available flow description information (e.g. source and destination IP address and port numbers and the protocol information) to enable the binding functionality and the generation or selection of the service data flow filter(s) in the PCC rules. The AF may also provide a ToS (IPv4) or TC (IPv6) value that is set by the application as part of the flow description information. The PCF generates a PCC Rule with service data flow filter(s) (either as IP Packet Filter set as defined in clause 5.7.6.2 of TS 23.501 or as Ethernet Packet Filter set as defined in clause 5.7.6.3 of TS 23.501) derived from the flow description information.
If SMF indicates that a PDU session is carried over NR satellite access or satellite backhaul, the PCF may take this information into account for the policy decision, e.g. together with any delay requirements provided by the AF.
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6.1.3.7  Service (data flow) prioritization and conflict handlingWord‑p. 60

Service pre-emption priority enables the PCF to resolve conflicts where the activation of all requested active PCC rules for services would result in a cumulative authorized QoS which exceeds the Subscribed Guaranteed bandwidth QoS.
If such a determination can be made, the PCF may resolve the conflict by deactivating those selected PCC rules with lower pre-emption priorities and accepting the higher priority service information from the AF. If such a determination cannot be made, the PCF may reject the service information from the AF.
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6.1.3.8  Termination actionWord‑p. 60

The termination action indicates the action which the SMF instructs the UPF to perform for all PCC rules of a Charging key for which credit is no longer available. The functional description for termination actions is described in TS 32.255.
The SMF shall revert the termination action related instructions for the UPF for all PCC rules of a Charging key when credit is available again.

6.1.3.9  Handling of packet filters provided to the UE by SMFWord‑p. 60

Traffic mapping information is signalled to the UE by the SMF in the Packet Filter Sets of QoS rules as defined in TS 23.501.
The network shall ensure that the traffic mapping information signalled to UE reflects the QoS Flow binding of PCC rules, except for those extending the inspection beyond what can be signalled to the UE. The PCC rules may restrict what traffic is allowed compared to what is explicitly signalled to the UE. The PCF may, per service data flow filter, indicate that the SMF is required to explicitly signal the corresponding traffic mapping information to the UE, e.g. for the purpose of IMS precondition handling at the UE. In absence of that indication, it is an SMF decision whether to signal the traffic mapping information that is redundant from a traffic mapping point of view.
For QoS Flow for services with no uplink IP flows, there is no need to provide any UL filter to the UE that effectively disallows any useful packet flows in uplink direction.
The default QoS rule will either contain a Packet Filter Set that allows all UL packets or a Packet Filter Set that is generated from the UL SDF filters (and from the DL SDF filters if they are available) which have an indication to signal corresponding traffic mapping information to the UE.
In the case of interworking with E-UTRAN connected to EPC, the specific aspects of the handling of packet filters at the SMF are described in clause 4.11.1 of TS 23.502.
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6.1.3.10  IMS emergency session supportWord‑p. 61

PDU Sessions for IMS Emergency services are provided by the serving network to support IMS emergency when the serving network is configured to support emergency services. The serving network may be either a PLMN or a SNPN. Emergency services are network services provided through an Emergency DNN and may not require a subscription depending on operator policies and local regulatory requirements. For emergency services, the architecture for the non-roaming case is the only applicable architecture model.
For emergency services, the N36 reference point does not apply. Emergency services are handled locally in the serving network.
For a PDU Session serving an IMS emergency session, the PCF makes authorization and policy decisions that restrict the traffic to emergency destinations, IMS signalling and the traffic to retrieve user location information (in the user plane) for emergency services. A PDU Session serving an IMS emergency session shall not serve any other service and shall not be converted to/from any PDU Session serving other services. The PCF shall determine based on the DNN if a PDU Session concerns an IMS emergency session.
The PCC Rule Authorization function selects QoS parameters that allow prioritization of IMS Emergency sessions. If an IMS Emergency session is prioritized the QoS parameters in the PCC Rule shall contain an ARP value that is reserved for intra-operator use of IMS Emergency services. The PCF does not perform subscription check; instead it utilizes the locally configured operator policies to make authorization and policy decisions.
For an emergency DNN, the PCF does not perform subscription check; instead it utilizes the locally configured operator policies to make authorization and policy decisions.
It shall be possible for the PCF to verify that the IMS service information is associated with a UE IP address belonging to an emergency DNN. If the IMS service information does not contain an emergency related indication and the UE IP address is associated with an emergency DNN, the PCF shall reject the IMS service information provided by the P CSCF (and thus to trigger the release of the associated IMS session), see TS 23.167.
In addition, the PCF shall provide the PEI and the subscriber identifiers (SUPI, GPSI) (if available), received from the SMF at PDU Session establishment, if so requested by the P-CSCF. The SUPI contains an IMSI or a network-specific identifier in the form of a NAI as defined in clauses 5.9.2 and 5.30.2.3 of TS 23.501. If the PCF removes all PCC Rules with a 5QI other than the default 5QI and the 5QI used for IMS signalling, the SMF shall start a configurable inactivity timer (e.g. to enable PSAP Callback session). When the configured period of time expires the SMF shall terminate the PDU Session serving the IMS Emergency session as defined in TS 23.502. If the SMF receives new PCC rule(s) with a 5QI other than the default 5QI and the 5QI used for IMS signalling for the PDU Session serving the IMS Emergency session, the SMF shall cancel the inactivity timer.
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6.1.3.11  Multimedia Priority Service supportWord‑p. 61

Multimedia Priority Services (MPS) is defined in TS 23.501, TS 23.502 and in TS 23.228, utilising the architecture defined for 5GS.
Subscription data for MPS is provided to PCF through the N36/Nudr. To support MPS service, the PCF shall subscribe to changes in the MPS subscription data for Priority PDU connectivity service. Dynamic invocation for MPS provided from an AF using the Priority indicator over N5/Npcf takes precedence over the MPS subscription.
ARP and/or 5QI may be modified. It shall be possible to override the default Priority Level associated with the standardized 5QI.
For dynamic invocation of MPS service, the PCF shall generate the corresponding PCC rule(s) with the ARP and 5QI parameters as appropriate for the prioritized service, as defined in TS 23.501.
Whenever one or more AF sessions of an MPS service are active within the same PDU Session, the PCF shall ensure that the ARP priority level of the QoS Flow for signalling as well as the QoS Flow associated with the default QoS rule is at least as high as the highest ARP priority level used by any authorized PCC rule belonging to an MPS service. If the ARP pre-emption capability is enabled for any of the authorized PCC rules belonging to an MPS service, the PCF shall also enable the ARP pre-emption capability for the QoS Flow for signalling as well as the QoS Flow associated with the default QoS rule.
In the case of IMS MPS, in addition to the above, the following QoS Flow handling applies:
  • At reception of the indication from subscription information that the IMS Signalling Priority is set for the PDU Session or at reception of service authorization from the P-CSCF (AF) including an MPS session indication and the service priority level as defined in TS 23.228, the PCF shall (under consideration of the requirement described in clauses 5.16.5 and 5.22.3 in TS 23.501) modify the ARP in all the PCC rules that describe the IMS signalling traffic to the value appropriate for IMS Multimedia Priority Services, if upgrade of the QoS Flow carrying IMS Signalling is required. To modify the ARP of the QoS Flow associated with the default QoS rule the PCF shall modify the Authorized default 5QI/ARP.
  • When the PCF detects that the P-CSCF (AF) released all the MPS sessions and the IMS Signalling Priority is not set for the PDU Session the PCF shall consider changes of the requirement described in clauses 5.16.5 and 5.22.3 in TS 23.501 and modify the ARP in all PCC rules that describe the IMS signalling traffic to an appropriate value according to PCF decision. The PCC rules bound to the QoS Flow associated with the default QoS rule have to be changed accordingly.
The Priority PDU connectivity service targets the ARP and/or 5QI of the QoS Flows, enabling the prioritization of all traffic on the same QoS Flow.
For non-MPS service, the PCF shall generate the corresponding PCC rule(s) as per normal procedures (i.e. without consideration whether the MPS Priority PDU connectivity service is active or not), and shall upgrade the ARP/5QI values suitable for MPS when the Priority PDU connectivity service is invoked. When the Priority PDU connectivity service is revoked, the PCF shall change the ARP/5QI values modified for the Priority PDU connectivity service to appropriate values according to PCF decision.
The PCF shall, at the activation of the Priority PDU connectivity service:
  • modify the ARP of PCC rules installed before the activation of the Priority PDU connectivity service to the ARP as appropriate for the Priority PDU connectivity service under consideration of the requirement described in clause 5.16.5 of TS 23.501; and
  • if modification of the 5QI of the PCC rule(s) is required, modify the 5QI of the PCC rules installed before the activation of the Priority PDU connectivity service to the 5QI as appropriate for this service.
The PCF shall, at the deactivation of the Priority PDU connectivity service modify any 5QI and ARP value to the value according to the PCF policy decision.
For PCC rules modified due to the activation of Priority PDU connectivity service:
  • modify the ARP to an appropriate value according to PCF decision under consideration of the requirement described in clauses 5.16.5 and 5.22.3 in TS 23.501; and
  • if modification of the 5QI of PCC rule(s) is required, modify the 5QI to an appropriate value according to PCF decision.
MPS for Data Transport Service enables the prioritization of all traffic on the QoS Flow associated with the default QoS rule and other QoS Flows upon AF request. The QoS modification to the QoS Flow associated with the default QoS rule and other QoS Flows is done based on operator policy and regulatory rules by means of local PCF configuration.
Upon receipt of an MPS for Data Transport Service invocation/revocation request from the UE, the AF or the PCF authorizes the request. If the UE has an MPS subscription, MPS for Data Transport Service is authorized by the AF or the PCF, based on AF decision. If the Service User is using a UE that does not have an MPS subscription, the AF authorizes MPS for Data Transport Service:
  • In the case that the AF authorizes the MPS for Data Transport Service request, after successful authorization, the AF sends the MPS for Data Transport Service request to the PCF over N5/Npcf for QoS Flow modifications, including an indication that PCF authorization is not needed. In this case, the PCF shall not perform any MPS subscription check for the MPS for Data Transport Service request. The AF also indicates to the PCF whether the request is for invoking or revoking MPS for Data Transport Service.
  • In the case that the AF does not authorize the MPS for Data Transport Service request, the AF sends the request to the PCF over N5/Npcf for authorization and QoS Flow modifications, including an indication that PCF authorization is needed. In this case, the PCF shall perform an MPS subscription check for the MPS for Data Transport Service request. The AF also indicates whether the request is for invoking or revoking MPS for Data Transport Service. The PCF will inform the AF when the UE does not have an MPS subscription associated with the request.
After successful authorization by either AF or PCF as described above, the PCF shall, at the invocation/revocation of MPS for Data Transport Service, perform the same steps for QoS modifications as described above for the activation/deactivation of the Priority PDU connectivity service.
The PCF shall inform the AF of the success or failure of the MPS for Data Transport Service invocation/revocation request. If the PDU Session is deactivated for other reasons that an AF request, the PCF shall notify the AF by deleting the N5 session context.
For MPS for Data Transport Service, the AF may also request an SDF for priority signalling between the UE and the AF, where the AF includes the Priority indicator over N5/Npcf, in order to enable the PCF to set appropriate QoS values for the QoS Flow.
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6.1.3.12  RedirectionWord‑p. 63

Redirection of uplink application traffic is an option applicable in SMF or in UPF.
PCF may control redirection by provisioning and modifying dynamic PCC rules over the N7 interface, or activate/deactivate the predefined redirection policies in SMF. The PCF may enable/disable redirection and set a redirect destination for every dynamic PCC rule. Redirect information (redirection enabled/disabled and redirect destination) within a PCC Rule instructs the SMF whether or not to perform redirection towards a specific redirect destination. The redirect destination may be provided as part of the dynamic PCC Rule, or may be preconfigured in the SMF or UPF. A redirect destination provided in a dynamic PCC Rule overrides the redirect destination preconfigured in the SMF or UPF for this PCC Rule.
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6.1.3.13  Resource sharing for different AF sessionsWord‑p. 63

The P-CSCF (i.e. AF) may indicate to the PCF that media of an AF session may share resources with media belonging to other AF sessions according to TS 23.228. For every media flow, the P-CSCF may indicate that the media flow may share resources in both directions or in one direction only (UL or DL).
The PCF makes authorization and policy decisions for the affected AF sessions individually and generates a PCC rule for every media flow in any AF session.
If the PCF received identical indication(s) for resource sharing for multiple AF sessions, the PCF may request the SMF to realize resource sharing for the corresponding set of PCC rules. The PCF provides a DL and/or UL sharing indication with the same value for those PCC rules that are candidate to share resources according to the direction of resource sharing indicated by the AF.
For each direction, the SMF shall take the highest GBR value from each set of PCC rules related with the same sharing indication for this direction and bound to the same QoS Flow and uses that value as input for calculating the GFBR of the QoS Flow. For each direction, the SMF may take the MBR value of the most demanding PCC rule included in each set of PCC rules related with the same sharing indication for this direction and bound to the same QoS Flow and uses that as input for calculating the MFBR of the QoS Flow.
The AF session termination or modification procedure that removes media flows triggers the removal of the corresponding PCC rules from the SMF. The SMF shall recalculate the GFBR (and MFBR) value of the QoS Flow whenever a set of PCC rules with the same sharing indication changes.
Resource sharing is applied as long as there are at least two active PCC rules with the same sharing indication bound to the same QoS Flow.
Resource sharing for different AF sessions is possible only if the P-CSCF, the PCF and the SMF support it.
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6.1.3.14  Traffic steering controlWord‑p. 64

Traffic steering control is triggered by the PCF initiated request and consists of steering the detected service data flows matching application detection filters or service data flow filter(s) in PCC Rules. The traffic steering control consists in one of the following:
  • AF influenced Traffic Steering: diverting (at DNAI(s) provided in PCC rules) traffic matching traffic filters provided by the PCF, as described in clause 5.6.7 of TS 23.501.
  • N6-LAN Traffic Steering: applying a specific N6 traffic steering policy for the purpose of steering the subscriber's traffic to appropriated N6 service functions deployed by the operator or a 3rd party service provider.
The PCF uses one or more pieces of information such as network operator's policies, user subscription, user's current RAT, network load status, application identifier, time of day, UE location, DNN, related to the subscriber session and the application traffic as input for selecting a traffic steering policy.
The PCF controls traffic steering by provisioning and modifying traffic steering control information in PCC rules. Traffic steering control information consists of a traffic description and in the case of N6-LAN Traffic Steering, a reference to a traffic steering policy that is configured in the SMF or, in the case of AF influenced Traffic Steering, per DNAI a reference to a traffic steering policy and/or N6 traffic routing information as well as other parameters described in clause 6.3.1 a reference to a traffic steering policy that is configured in the SMF.
The SMF instructs the UPF to perform necessary actions to enforce the traffic steering policy referenced by the PCF. The actual traffic steering applies at the UPF. For enforcing the traffic steering policy, the UPF may support traffic steering related functions as defined by other standard organizations. The mechanism used for routing the traffic over N6 is out of 3GPP scope.
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6.1.3.15  Resource reservation for services sharing priorityWord‑p. 64

An AF may indicate to the PCF that a media flow of an AF session is allowed to use the same priority as media flows belonging to other AF sessions (instead of the service priority provided for this media flow). In this case, the AF will provide a priority sharing indicator in addition to the application identifier and the service priority. For MCPTT, the service priority and the priority sharing indicator are defined in TS 23.179. The priority sharing indicator is used to indicate what media flows are allowed to share priority.
The PCF makes authorization and policy decisions for the affected AF sessions individually and generates a PCC rule for every media flow as specified in clause 6.1.1.3. The application identifier and the service priority are used to calculate the ARP priority. The AF may also provide suggested pre-emption capability and vulnerability values per media flow to the PCF. The ARP pre-emption capability and the ARP pre-emption vulnerability are set according to operator policies and regulatory requirements, also taking into consideration the application identifier and suggested values, when provided by the AF. The priority sharing indicator is stored for later use.
For PCC rules with the same 5QI assigned and having an associated priority sharing indicator, the PCF shall try to make authorization and policy decisions taking the priority sharing indicator into account and modify the ARP of these PCC rules as follows, (the original ARP values are stored for later use):
  • The modified ARP priority is set to the highest of the original priority among all the PCC rules that include the priority sharing indicator;
  • The modified ARP pre-emption capability is set if any of the original PCC rules have the ARP pre-emption capability set;
  • The modified ARP pre-emption vulnerability is set if all the original PCC rules have the ARP pre-emption vulnerability set.
If the PCF receives an indication that a PCC rule provisioning or modification failed (due to resource reservation failure) then, the PCF may apply pre-emption and remove active PCC rules from the SMF and then retry the PCC rule provisioning or modification. If the PCF does not apply pre-emption, the AF is notified using existing procedures that the resource reservation for the new media flow failed.
The AF may optionally provide pre-emption control information, including pre-emption capability and vulnerability values, in addition to the priority sharing indicator to the PCF. If so, the PCF shall apply pre-emption and remove active PCC rules according to this information when receiving an indication that a PCC rule provisioning or modification failed. The pre-emption control information indicates:
  • whether media flows sharing priority are candidates to being pre-empted taking into account pre-emption capability and vulnerability values;
  • how to perform pre-emption among multiple potential media flow candidates of same priority: most recently added media flow, least recently added media flow, media flow with highest requested bandwidth in the AF request.
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6.1.3.16  3GPP PS Data OffWord‑p. 65

This feature, when activated by the user, prevents traffics via 3GPP access except for 3GPP PS Data Off Exempt Services. The 3GPP PS Data Off Exempt Services are a set of operator services, defined in TS 22.011 and TS 23.221, that are the only allowed services in both downlink and uplink direction when the 3GPP PS Data Off feature has been activated by the user.
When PCF is deployed, it shall be able to configure the list(s) of 3GPP PS Data Off Exempt Services for 3GPP access, and the Policy Control Request Trigger of 3GPP PS Data Off status change used to inform the PCF from SMF about every change of the 3GPP PS Data Off status.
When the PCF is informed about the activation of 3GPP PS Data Off, it shall update the PCC rules in such a way that for 3GPP access only packets for services belonging to the list(s) of 3GPP PS Data Off Exempt Services are forwarded while all other packets are discarded. Packets sent over non-3GPP access are not affected, and in the case of MA PDU Session, this is ensured by the MA PDU Session Control policy, e.g. for packets not belonging to the 3GPP Data Off Exempt Services, PCF provides PCC rule containing Steering Mode "Active-Standby" with active access as non-3GPP access and no standby access for downlink and uplink direction.
When the PCF receives service information from the AF, in addition to what is specified in clause 6.2.1, PCF shall check if the requested service information belongs to the 3GPP PS Data Off Exempt Services. If the requested service belongs to 3GPP PS Data Off Exempt Services or if the service traffic can be sent over non-3GPP access, PCF shall continue as specified in clause 6.2.1. If the requested service doesn't belong to the 3GPP PS Data Off Exempt Services and the PDU Session is established only over 3GPP access, PCF shall reject the service request.
When the PCF is informed about the deactivation of 3GPP PS Data Off, it shall perform policy control decision as specified in clause 6.2.1 and perform PCC rule operations as specified in clause 6.3.2 to make sure that the services are allowed according to user's subscription and operator policy (irrespective of whether they belong to the list(s) of 3GPP PS Data Off Exempt Services).
When PCF is not deployed, predefined PCC rules, can be configured in the SMF, on a per DNN basis, to ensure the following:
  • when the SMF is informed about activation of 3GPP PS Data Off, the SMF shall update the predefined PCC rule in a way that for 3GPP access only downlink and optionally uplink packets for services belonging to the list(s) of 3GPP PS Data Off Exempt Services are forwarded while all other downlink and uplink packets are discarded. Packets sent over non-3GPP access are not affected, and in the case of MA PDU Session, this is ensured by the MA PDU Session Control policy, e.g. for packets not belonging to the 3GPP Data Off Exempt Services, the SMF applies predefined PCC rule containing Steering Mode "Active-Standby" with active access as non-3GPP access and no standby access for downlink and uplink direction; and
  • When SMF is informed about deactivation of 3GPP PS Data Off, the SMF ensures in UPF downlink and uplink packets are forwarded according to the operator policy for the subscriber.
When the UE 3GPP PS Data Off status is "active" and a handover from one access-system to another occurs, the PCF or the SMF when PCF is not deployed performs the above operations so that the downlink and optionally uplink traffic for services not belonging to the list(s) of 3GPP PS Data Off Exempt Services is only prevented via the 3GPP access.
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6.1.3.17  Policy decisions based on spending limitsWord‑p. 66

Policy decisions based on spending limits is a function that allows PCF taking actions related to the status of policy counters that are maintained in the CHF.
The PCF uses the CHF selection mechanism defined in TS 23.501 to select the CHF that provides policy counters for spending limits for a PDU Session. The PCF shall also provide the selected CHF address(es) to the SMF in the PDU Session related policy information.
The identifiers of the policy counters that are relevant for a policy decision in the PCF may be stored in the PCF or possibly in UDR. The PCF is configured with the actions associated with the policy counter status that is received from CHF.
The PCF may retrieve the status of policy counters in the CHF using the Initial or Intermediate Spending Limit Report Retrieval Procedure. The CHF provides the current status of the policy counters to the PCF. The CHF may in addition provide one or more pending statuses for a policy counter together with the time they have to be applied. The PCF shall immediately apply the current status of a policy counter. A pending status of a policy counter shall autonomously become the current status of a policy counter at the PCF when the indicated corresponding time is reached. Subsequently provided information for pending statuses of a policy counter shall overwrite the previously received information.
The PCF may subscribe to spending limit reporting for policy counters from the CHF using the Initial or Intermediate Spending Limit Report Retrieval procedure. If spending limit reporting for a policy counter is enabled, the CHF shall notify the PCF of changes in the status of this policy counter (e.g. daily spending limit of $2 reached) and optionally pending statuses of this policy counter together with their activation time (e.g. due to a billing period that will expire at midnight). The PCF may cancel spending limit reporting for specific policy counter(s) using the Intermediate Spending Limit Report Retrieval procedure, or for all policy counter(s) using the Final Spending Limit Report Retrieval procedure.
The PCF uses the status of each relevant policy counter, and optional pending policy counter statuses if known, as input to its policy decision to apply operator defined actions, e.g. change the QoS (e.g. downgrade Session-AMBR), modify the PCC Rules to apply gating or change charging conditions.
The CHF may report to the PCF the removal of the subscriber from the CHF system, and the PCF shall remove all the policy counters of the subscriber accordingly.
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6.1.3.18  Event reporting from the PCFWord‑p. 68

The AF may subscribe/unsubscribe to notifications of events from the PCF for the PDU Session to which the AF session is bound. Alternatively, a PCF for the UE may subscribe/unsubscribe to notifications from the PCF for the PDU Session of this UE.
The events that can be subscribed by the AF and by the PCF for the UE are listed in Table 6.1.3.18-1.
Event Description Conditions for reporting Availability for Rx PDU Session (NOTE 2) Availability for N5 per PDU Session Availability for Bulk Subscription (NOTE 1) Availability for N43 per SUPI, DNN, S-NSSAI Availability for N5 per UE (NOTE 6)
PLMN Identifier Notification (NOTE 5)The PLMN identifier or SNPN identifier where the UE is currently located.AFYesYesYesNoNo
Change of Access TypeThe Access Type and, if applicable, the RAT Type of the PDU Session has changed.AFYesYesYesNoNo
EPS fallbackEPS fallback is initiatedAFYesYesNoNoNo
Signalling path statusThe status of the resources related to the signalling traffic of the AF session.AFYesYesNoNoNo
Access Network Charging Correlation InformationThe Access Network Charging Correlation Information of the resources allocated for the AF session.AFYesYesNoNoNo
Access Network Information NotificationThe user location and/or timezone when the PDU Session has changed in relation to the AF session.AFYesYesNoNoNo
Reporting Usage for Sponsored Data ConnectivityThe usage threshold provided by the AF has been reached; or the AF session is terminated.AFYesYesNoNoNo
Service Data Flow deactivationThe resources related to the AF session are released.AFYesYesNoNoNo
Resource allocation outcomeThe outcome of the resource allocation related to the AF session.AFYesYesNoNoNo
QoS targets can no longer (or can again) be fulfilledThe QoS targets can no longer (or can again) be fulfilled by the network for (a part of) the AF session.AFNoYesNoNoNo
QoS Monitoring parametersThe QoS Monitoring parameter(s) (e.g. UL packet delay, DL packet delay or round trip packet delay) are reported to the AF according to the QoS Monitoring reports received from the SMF.AFNoYesNoNoNo
Out of creditCredit is no longer available.AFYesYesNoNoNo
Reallocation of creditCredit has been reallocated after the former Out of credit indication.AFYesYesNoNoNo
5GS Bridge information Notification (NOTE 3)5GS Bridge information that has been received by PCF from SMF.AF, TSCTSFNoYesNoNoNo
Notification on outcome of service area coverage changeThe outcome of the request of service area coverage change.AFNoNoYesNoYes
Notification on outcome of UE Policies deliveryThe outcome of the request for UE policies delivery due to service specific parameter provisioning procedure.AFNoNoNoNoNo
Start of application traffic detection and Stop of application traffic detectionThe start or the stop of application traffic has been detected.PCFNoNoNoYes (NOTE 4)No
Satellite backhaul category changeThe backhaul has changed between different satellite backhaul categories (i.e. GEO, MEO, LEO, OTHERSAT), or the backhaul has changed between satellite backhaul and non-satellite backhaul.AFNoYesYesNoNo
Change of PDUIDThe PDUID assigned to a UE has changed.5G DDNMFNoNoNoNoYes
SM Policy Association established or terminatedThe establishment or termination of a SM Policy Association is reportedPCFNoNoNoYes (NOTE 7)No
NOTE 1:
Additional parameters for the subscription as well as reporting related to these events are described in TS 23.502.
NOTE 2:
Applicability of Rx is described in Annex C.
NOTE 3:
5GS Bridge information is described in clause 6.1.3.5.
NOTE 4:
Bulk subscription is implicit. NOTE 1 does not apply.
NOTE 5:
For a PDU Session established over a SNPN, the combination of the PLMN id and the NID identifies the SNPN.
NOTE 6:
This column contains also UE context related events that are reported to other consumers such as 5G DDNMF via other reference points than N5. The Conditions for reporting column indicates the respective consumer.
NOTE 7:
This PCF for the UE subscribes to this Event via AMF and SMF.
If an AF requests the PCF to report the PLMN identifier where the UE is currently located, then the PCF shall provide the PLMN identifier or the SNPN identifier to the AF if available. Otherwise, the PCF shall provision the corresponding PCC rules, and the Policy Control Request Trigger to report PLMN change to the SMF. The PCF shall, upon receiving the PLMN identifier or the SNPN identifier from the SMF forward this information to the AF, including the PLMN Id and if available the NID.
If an AF requests the PCF to report on the change of Access Type, the PCF shall provide the corresponding Policy Control Request Trigger to the SMF to enable the report of the Change in Access Type to the PCF. The PCF shall, upon reception of information about the Access Type the user is currently using and upon indication of change of Access Type, notify the AF on changes of the Access Type and forward the information received from the SMF to the AF. The change of the RAT Type shall also be reported to the AF, even if the Access Type is unchanged. For MA PDU Session the Access Type information may include two Access Type information that the user is currently using.
If an AF requests the PCF to report on the signalling path status, for the AF session, the PCF shall, upon indication of removal of PCC Rules identifying signalling traffic from the SMF report it to the AF.
If an AF requests the PCF to report Access Network Charging Correlation Information, the PCF shall provide to the AF the Access Network Charging Correlation Information, which allows to identify the usage reports that include measurements for the Service Data Flow(s), once the Access Network Charging Correlation Information is known at the PCF.
If an AF requests the PCF to report Access Network Information (i.e. the User Location Report and/or the UE Timezone Report) at AF session establishment, modification or termination, the PCF shall set the Access Network Information report parameters in the corresponding PCC rule(s) and provision them together with the corresponding Policy Control Request Trigger to the SMF. For those PCC rule(s) based on preliminary service information the PCF may assign the 5QI and ARP of the QoS Flow associated with the default QoS rule to avoid signalling to the UE.
The PCF shall, upon receiving an Access Network Information report corresponding to the AF session from the SMF, forward the Access Network Information as requested by the AF (if the SMF only reported the serving PLMN identifier or the SNPN identifier to the PCF, as described in clause 6.1.3.5, the PCF shall forward it to the AF). For AF session termination the communication between the AF and the PCF shall be kept alive until the PCF report is received.
If an AF requests the PCF to report the Usage for Sponsored Data Connectivity, the PCF shall provision the corresponding PCC rules, and the Policy Control Request Trigger to the SMF. If the usage threshold provided by the AF has been reached or the AF session is terminated, the PCF forwards such information to the AF.
If an AF requests the PCF to report the Service Data Flow deactivation, the PCF shall report the release of resources corresponding to the AF session. The PCF shall, upon being notified of the removal of PCC Rules corresponding to the AF session from the SMF, forward this information to the AF. The PCF shall also forward, if available, the reason why the resources are released, the user location information and the UE Timezone.
If an AF requests the PCF to report the Resource allocation outcome, the PCF shall report the outcome of the resource allocation of the Service Data Flow(s) related to the AF session. The AF may request to be notified about successful or failed resource allocation. In this case, the PCF shall instruct the SMF to report the successful resource allocation trigger (see clause 6.1.3.5). If the SMF has notified the PCF that the resource allocation of a Service Data Flow is successful and the currently fulfilled QoS matches an Alternative QoS parameter set (as described in clause 6.2.2.1), the PCF shall also provide to the AF the QoS Reference parameter or the Requested Alternative QoS Parameter Set which corresponds to the Alternative QoS parameter set referenced by the SMF.
If an AF requests the PCF to report when the QoS targets can no longer (or can again) be fulfilled for a particular media flow, the PCF shall set the QNC indication in the corresponding PCC rule(s) that includes a GBR or delay critical GBR 5QI value and provision them together with the corresponding Policy Control Request Trigger to the SMF. At the time, the SMF notifies that GFBR can no longer (or can again) be guaranteed for a QoS Flow to which those PCC Rule(s) are bound, the PCF shall report to the AF the affected media flow and provides the indication that QoS targets can no longer (or can again) be fulfilled. If additional information is received with the notification from SMF (see clause 5.7.2.4 of TS 23.501), the PCF shall also provide to the AF the QoS Reference parameter or the Requested Alternative QoS Parameter Set which corresponds to the Alternative QoS parameter set referenced by the SMF. If the SMF has indicated that the lowest priority Alternative QoS parameter set cannot be fulfilled, the PCF shall indicate to the AF that the lowest priority QoS Reference or the lowest priority set of Requested Alternative QoS Parameters of the Alternative Service Requirements cannot be fulfilled.
If the AF has subscribed to be notified of the QoS Monitoring information, the PCF further sends the QoS Monitoring report to the AF.
If an AF requests the PCF to report on the Out of credit event for the associated service data flow(s), the PCF shall inform the AF (when it gets informed by the SMF) that credit is no longer available for the services data flow(s) related to the AF session together with the applied termination action.
If an AF requests the PCF to report on the Reallocation of credit event for the associated service data flow(s), the PCF shall inform the AF (when it gets informed by the SMF) that credit has been reallocated after credit was no longer available and the termination action was applied for the service data flow(s) related to the AF session.
The PCF can arm the trigger of 5GS Bridge information available to SMF based on local policy without an AF request or based on subscription request from TSCTSF. The PCF shall, upon reception of the 5GS Bridge information (refer to clause 6.1.3.23) from the SMF, forward this information to the TSN AF or the TSCTSF. When the PCF has received the User plane node Management Information Container or Port Management Information Container and related port number from SMF, the PCF also provides User plane node Management Information Container or Port Management Information Container and related port number to the TSN AF or TSCTSF. When SMF has reported the 5GS Bridge information and no AF session exists, the PCF forward this information to a pre-configured TSN AF, or to a pre-configured TSCTSF or a TSCTSF discovered and selected via NRF and in the case of private IPv4 address being used for IP type PDU Session, the PCF shall additionally report DNN and S-NSSAI of the PDU Session to TSCTSF.
If the AF requests the PCF to report on the outcome of the service area coverage change, the PCF reports the outcome of the service area coverage change to the AF and notifies the current service area coverage to the AF. The outcome is the result of the execution of the request of service coverage change at the PCF; the outcome is successful if the request was executed, and includes the current service area coverage that may be the same or different from the service area coverage provided by the AF. The subscription may also be implicit. In this case there may be bulk subscription, either for an Internal-Group-Id or for any UE. In order to prevent massive notifications to the AF, the request for any UE is associated to a specific Application Identifier or DNN, S-NSSAI. For bulk subscription, when the AF request includes an expiration time, the PCF stops reporting to the AF when the expiration time is reached.
If the AF requests the PCF to report on the outcome of the UE Policies delivery due to service specific parameter provisioning procedure targeting a single UE, the PCF reports the outcome of the related UE Policies provisioning procedure for the related traffic descriptor for the UE. The outcome of the UE Policies provisioning procedure includes the success, the failure with an appropriate cause or the interim status report such as UE is temporarily unreachable. (See clauses 4.15.6.7 and 5.2.5.7 of TS 23.502)
A request to report Start of application traffic detection and Stop of application traffic detection triggers the reporting when the PCF receives start of application traffic detection event or stop of application traffic detection event from SMF. The reception of a subscription to this event triggers the setting of the corresponding Policy Control Request Trigger to SMF, if not already subscribed.
If an AF requests the PCF to report on the change between different satellite backhaul categories (i.e. GEO, MEO, LEO, OTHERSAT) or the change between satellite backhaul and non-satellite backhaul, the PCF shall provide the corresponding Policy Control Request Trigger to the SMF to enable the report of satellite backhaul category change (see clause 6.1.3.5) to the PCF. The PCF shall, upon reception of information about the change between satellite backhaul categories or change between satellite backhaul and non-satellite backhaul, notify the AF on the satellite backhaul category change event was met and forward the current satellite backhaul category information received from the SMF to the AF, or indicate that a satellite backhaul is no longer used.
If 5G DDNMF requests the PCF to report on the Change of PDUID, the PCF shall notify whenever a new PDUID is allocated. Further details on how the 5G DDNMF retrieves and subscribes to notifications on Change of PDUID are defined in TS 23.304.
A request to report SM Policy Association established or terminated triggers the reporting when the PCF receives the request for notification on the SM Policy Association from SMF. The PCF notifies on the EventID "SM Policy Association established/terminated", includes the PCF binding information of the PCF for the PDU Session of the UE, as described in clause 6.1.1.2.2.
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6.1.3.19  Mission Critical Services supportWord‑p. 74

Mission Critical Services are defined in TS 23.501, TS 23.502 and in TS 23.280, utilising the architecture defined for 5GS.
Subscription data for MCX services are provided to PCF through the N36/Nudr. To support MCX services, the PCF shall subscribe to changes in the MCX services subscription data for Priority PDU connectivity service. Dynamic invocation for MCX services provided from an AF using the Priority indicator over N5/Npcf takes precedence over the MCX services subscription.
For MCX services the session management relate policy control functionality of the Policy and Charging control framework for the 5G system is as defined in clause 6.1.3.11 for Multimedia Priority Service.
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6.1.3.20  Access Traffic Steering, Switching and Splitting |R16|Word‑p. 74

As specified in TS 23.501, the Access Traffic Steering, Switching and Splitting (ATSSS) feature is an optional feature that may be supported by the UE and the 5GC network.
The ATSSS feature enables a multi-access PDU Connectivity Service, which can exchange PDUs between the UE and a data network by simultaneously using one 3GPP access network and one non-3GPP access network (both connected to 5GC) when both accesses are allowed for the same S-NSSAI. The multi-access PDU Connectivity Service also supports the exchange of PDUs between the UE and a data network by simultaneously using one 3GPP access network in EPC and one non-3GPP access network in 5GC, as described in TS 23.501. This enables a scenario where a MA PDU Session can simultaneously be associated with user-plane resources on 3GPP access network connected to 5GC or EPC and non-3GPP access connected to 5GC.
The PCF is informed of the ATSSS capabilities of a MA PDU Session by the SMF, as defined in clause 5.32.2 of TS 23.501. The ATSSS capabilities are both the Steering Mode and the Steering Functionality.
The PCF control of Access Traffic Steering, Switching and Splitting for a detected service data flow (SDF) is enabled by including Multi-Access PDU (MA PDU) Session Control information in the PCC rule. This allows the PCF to control:
  • The Steering Mode that is used to steer/switch/split the detected SDF. The available Steering Modes are defined in TS 23.501.
  • The Steering Functionality that is used for the detected SDF, e.g. the MPTCP functionality or the ATSSS-LL functionality defined in TS 23.501.
  • The Steering Mode Indicator authorized for the detected SDF.
  • The Threshold values for RTT and Packet Loss Rate authorized for the detected SDF.
  • The Charging information depending on what Access Type is used for a detected SDF.
  • The Usage Monitoring information depending on what Access Type is used for a detected SDF.
The rest of the information in the PCC Rule apply to the SDF as such and are not dependent on what Access Type is used for a packet.
The MA PDU Session Control information in the PCC rules is used by the SMF in order to create applicable N4 rules for the UPF and ATSSS rules for the UE, as described in TS 23.501. The ATSSS rules are sent to UE via NAS when the MA PDU Session is created or updated by the SMF/PCF, as described in TS 23.501 and TS 23.502.
When MA PDU Session Control Information is provided to the SMF within a PCC Rule, the (H-)PCF provides both the Service Data Flow templates to identify a Service Data Flow in the UPF and if the Service Data Flow template includes an application identifier, then the corresponding Application descriptors to identify the application traffic in the UE is also included.
The (H-) PCF may use the OSid stored in the UDR as DataSet "Policy Data" and Data Subset "UE context policy control data" to determine the OSAppId supported by the OSid. The (H-)PCF may also provide multiple Application descriptors to identify application traffic in the UE, this is determined by the (H-)PCF local policies that indicates e.g. the operating system supported by the UE. If no OSid is available in the UDR, the (H-)PCF may use the PEI to determine the OSid supported by the UE.
The Traffic Descriptor in the ATSSS rule is generated by the SMF from the SDF template of the PCC rule. If the SDF template contains SDF filters, the SMF uses the UL SDF filters for the generation of the IP descriptors or Non-IP descriptors, respectively. If the SDF template contains an application identifier, the SMF includes the Application descriptors received from the PCF as part of the MA PDU Session information in the PCC Rule within the Traffic Descriptors in the ATSSS rule.
For the Load-Balancing steering mode with fixed split percentages (i.e. without the Autonomous load-balance indicator or UE-assistance indicator), the PCF may provide one or more threshold values together with the split percentages. For the Priority-based steering mode, the PCF may provide one or more threshold values together with the priority of the accesses. One threshold value for the Round Trip Time (RTT) and/or one threshold value for the Packet Loss Rate (PLR) may be included in a PCC Rule. The threshold values are not dependent on what Access Type is used for a packet, i.e. a given threshold value is applicable to both accesses. The threshold values are applied by the UE and UPF as described in TS 23.501.
The MA PDU Session Control information in a PCC rule may contain only one of the following Steering Mode Indicators:
  • Autonomous load-balance indicator: This indicator may be included only when the Steering Mode is Load-Balancing and indicates whether autonomous load-balance operation is allowed. Further details are specified in clause 5.32.8 of TS 23.501.
  • UE-assistance indicator: It indicates that the UE can decide how to distribute the UL traffic based on its internal state (e.g. battery level), and that the UE can request from UPF to apply the same distribution for the DL traffic. Further details are specified in clause 5.32.8 of TS 23.501.
The PCF may also provide URSP rules to the UE for instructing the UE to establish a MA PDU Session, as described in clause 6.6.2.
The PCF control of PDU Session level Usage Monitoring depending on what access type is used to carry the traffic is enabled by providing Usage Monitoring control related information per access in the PDU Session related policy control information (as described in clause 6.4).
If the MA PDU Session is capable of MPTCP and ATSSS-LL with any Steering Mode in the downlink and MPTCP and ATSSS-LL with Active-Standby in the uplink, then the PCF shall provide a PCC Rule for non-MPTCP traffic. This PCC Rule contains a "match all" SDF template, the lowest precedence, the Steering Functionality set to "ATSSS-LL" and the Steering Mode set to "Active-Standby" for the uplink direction, and the Steering Functionality set to "ATSSS-LL" and the Steering Mode set to any supported steering mode for the downlink direction.
If the MA PDU Session is capable of MPTCP with any Steering Mode in the downlink, ATSSS-LL with any steering mode except Smallest Delay steering mode in the downlink, and MPTCP and ATSSS-LL with Active-Standby in the uplink, then the PCF shall provide a PCC Rule for non-MPTCP traffic. This PCC Rule contains a "match all" SDF template, the lowest precedence, the Steering Functionality set to "ATSSS-LL" and the Steering Mode set to "Active-Standby" for the uplink direction, and the Steering Functionality set to "ATSSS-LL" and the Steering Mode set to any supported steering mode except Smallest Delay steering mode for the downlink direction.
If the MA PDU Session is capable of MPTCP and ATSSS-LL with Active-Standby in the uplink and downlink, then the PCF shall provide a PCC Rule for non-MPTCP traffic. This PCC Rule contains a "match all" SDF template, the lowest precedence, the Steering Functionality set to "ATSSS-LL" and the Steering Mode set to "Active-Standby" for the uplink direction and the downlink direction.
If the MA PDU Session is capable of MPTCP and ATSSS-LL with any Steering Mode in the uplink and downlink, then the PCF shall provide a PCC Rule for non-MPTCP traffic. This PCC Rule may contain a "match all" SDF template, the lowest precedence, the Steering Functionality set to "ATSSS-LL" and the Steering Mode set to any supported steering mode for the uplink direction and for the downlink direction.
These PCC Rules are used by the SMF to generate an ATSSS rule for the UE and an N4 rule for the UPF to route the non-MPTCP traffic of the MA PDU Session in the uplink and downlink direction respectively.
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6.1.3.21  QoS Monitoring to assist URLLC Service |R16|Word‑p. 76

The QoS Monitoring for URLLC refers to the real time packet delay measurement between the UE and the UPF for a QoS Flow corresponding to an URLLC service.
The PCF generates the authorized QoS Monitoring policy for the service data flow based on the QoS Monitoring request if received from the AF. The QoS Monitoring policy includes the following:
  • QoS parameters to be measured (DL, UL or round trip packet delay);
  • frequency of reporting (event triggered, periodic, when no packet delay measurement result is received for a delay exceeding a threshold, or when the PDU Session is released):
    • if the reporting frequency is event triggered:
      • the corresponding reporting threshold to each QoS parameter;
      • minimum waiting time between subsequent reports;
    • if the reporting frequency is periodic, the reporting period;
    • threshold for reporting packet delay measurement failure;
  • information about the target of the QoS Monitoring reports (e.g. the PCF or the AF or the Local NEF indicated as Notification Target Address + Notification Correlation ID as specified in clause 4.15.1 of TS 23.502);
  • an indication of direct event notification (to request the UPF to directly report QoS Monitoring information to the Local NEF or the AF as described in clause 6.4 of TS 23.548).
The PCF includes the authorized QoS Monitoring policy in the PCC rule and provides it to the SMF.
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6.1.3.22  AF session with required QoS |R16|Word‑p. 76

The AF may request that a data session to a UE is set up with a specific QoS (e.g. low latency or jitter) and priority handling. The AF can request the network to provide QoS for the AF session based on the service requirements with the help of a QoS Reference parameter that refers to pre-defined QoS information. Instead of the QoS Reference, the AF may provide individual QoS parameters associated to the Flow Description.
  1. When the AF provides only a QoS Reference to determine the QoS parameters but no individual QoS parameters:
    • When the PCF authorizes the service information from the AF, it derives the QoS parameters of the PCC rule based on the service information and the indicated QoS Reference.
    • The AF may change the QoS by providing a different QoS Reference while the AF session is ongoing. If this happens, the PCF shall update the related QoS parameter sets in the PCC rule accordingly.
  2. When the AF provides individual QoS parameters instead of a QoS Reference:
    • The AF provides one or more of the following individual QoS parameters, i.e. Requested Priority, Maximum Burst Size, Requested 5GS Delay, Requested Maximum Bitrate and Requested Guaranteed Bitrate.
    • If the AF request for QoS is sent via the TSCTSF and the request contains a Requested 5GS Delay, the TSCTSF determines a Requested PDB considering the UE-DS-TT Residence Time (either provided by the PCF or pre-configured).
    • When the PCF authorizes the service information from the AF, it derives the QoS parameters of the PCC rule based on the service information and the individual QoS information received from the AF and TSCTSF. The PCF should select a standardized, pre-configured or existing dynamically assigned 5QI that matches the individual QoS parameters. If no 5QI exists that matches the individual QoS parameters, the PCF generates a new dynamically assigned 5QI based on the individual QoS parameters.
    • The AF may change the QoS by providing different values for the individual QoS parameters while the AF session is ongoing. If this happens, the PCF shall update the related QoS parameter sets in the PCC rule accordingly.
    • The PCF may reject the individual QoS parameters received from the AF based on operator policy or impossibility to support the requested values of the individual QoS parameters. If this happens, the PCF may provide in the response to the AF one or more combinations of individual QoS parameters that can be supported.
In addition to the QoS reference or the individual QoS parameters described above, the AF may provide the following QoS Parameters associated with the Flow Description. One of the following:
  1. In the case that the AF takes the role of TSN AF which is a 5GC NF: TSC Assistance Container: describing the traffic characteristics and needed for TSCAI determination (as described in clause 5.27.2.4 of TS 23.501); or
  2. In the case that the AF is not the TSN AF: parameters that describe traffic characteristics and subsequently used for the determination of TSC Assistance Container as described in clause 5.27.2.3 of TS 23.501.
The PCF generates a PCC Rule with service data flow filter (including IP Packet Filter set as in clause 5.7.6.2 of TS 23.501) or Ethernet Packet Filter set as in clause 5.7.6.3 of TS 23.501) derived from the Flow Descriptions provided by the AF, the derived PCC rule QoS parameters such a 5QI, ARP, GBR and MBR (see clause 6.3.1 for all possible PCC rule QoS parameters) and the associated TSC Assistance Container as received from the TSN AF or TSCTSF.
For TSC QoS, the PCF derives the 5QI value as defined in clause 5.27.3 of TS 23.501, the PCF derives the MBR using the Requested Maximum Bitrate provided by the AF and sets the GBR equal to the MBR unless the AF provides a Requested Guaranteed Bitrate, in which case the MBR and GBR are set separately.
If the PCF gets informed about Policy Control Request Triggers relevant for the AF session, the PCF shall inform the AF about it as defined in clause 6.1.3.18.
If an AF session can adjust to different QoS parameter combinations, the AF may provide Alternative Service Requirements in a prioritized order (indicating the preference of the QoS requirements with which the service can operate) in addition to the QoS Reference or individual QoS parameters. Alternative Service Requirements contain:
  • When the AF requests the network to provide QoS with a QoS reference, one or more QoS Reference parameters in a prioritized order.
  • When the AF requests the network to provide QoS with individual QoS parameters, one or more Requested Alternative QoS Parameter Set(s) in a prioritized order. Each Requested Alternative QoS Parameter Set is comprised of the following individual parameters: Requested 5GS Delay and Requested Guaranteed Flow Bitrate.
    If the AF request is sent via the TSCTSF, the TSCTSF determines a Requested PDB considering the Requested 5GS Delay and the UE-DS-TT Residence Time.
An AF that provides Alternative Service Requirements shall also subscribe to receive notifications from the PCF for successful resource allocation and when the QoS targets can no longer (or can again) be fulfilled as described in clause 6.1.3.18.
When the PCF authorizes the service information from the AF and generates a PCC rule, it shall also derive Alternative QoS Parameter Sets for this PCC rule based on the QoS Reference parameters or the Requested Alternative QoS Parameter Sets in the Alternative Service Requirements. If the AF provided Requested Alternative QoS Parameter Sets in the request, the PCF may reject any of the Requested Alternative QoS Parameter Sets it has received based on operator policy or impossibility to support the requested values of the individual parameters. If this happens, the PCF may provide in the response to the AF one or more Requested Alternative QoS Parameters Sets that can be supported.
The PCF shall enable QoS Notification Control and include the derived Alternative QoS parameter sets (in the same prioritized order indicated by the AF) in the PCC rule sent to the SMF. When the PCF notifies the AF that QoS targets can no longer be fulfilled, the PCF shall include the QoS Reference parameter or the set of Requested Alternative QoS Parameters corresponding to the Alternative QoS parameter set referenced by the SMF, or an indication that the lowest priority QoS Reference or the lowest priority set of Requested Alternative QoS Parameters of the Alternative Service Requirements cannot be fulfilled (as described in clause 6.1.3.18).
The AF may change the Alternative Service Requirements while the AF session is ongoing. If this happens, the PCF shall update the Alternative QoS parameter sets in the PCC rule accordingly.
The AF may indicate to the PCF that the UE does not need to be informed about changes related to Alternative QoS Profiles. With this indication received from the AF, the PCF decides whether to disable the notifications to the UE when changes related to the Alternative QoS Profiles occur and sets the Disable UE notifications at changes related to Alternative QoS Profiles parameter in the PCC rule accordingly.
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6.1.3.23  Support of integration with Time Sensitive Networking |R16|Word‑p. 78

Time Sensitive Networking (TSN) support is defined in TS 23.501, where the 5GS represents logical TSN bridge(s) based on the defined granularity model. The TSN AF and PCF interact to perform QoS mapping as described in clause 5.28.4 of TS 23.501.
The PCF provides the following parameters to the TSN AF:
  • 5GS user-plane Node information:
    • 5GS Bridge ID;
    • UE-DS-TT Residence time;
    • port number of the Ethernet port of DS-TT;
    • MAC address of the Ethernet port of DS-TT (i.e. DS-TT port MAC address).
  • Port Management Information Container and the related port number.
    • User plane node Management Information Container.
The TSN AF may use this information to construct IEEE 802.1 managed objects, to interwork with IEEE 802.1 TSN networks, as described in TS 23.501 and TS 23.502.
The TSN AF may use the PTP Port state of NW-TT and DS-TT in the Port/User plane node Management Information Container to determine the Port Pairs that will be used for (g)PTP delivery. Based on this the TSN AF may request appropriate QoS treatment for the (g)PTP flows from PCF.
The TSN AF request related to TSN configuration or gPTP flow delay requirement is sent on the AF session associated with the DS-TT port MAC address. The TSN AF decides the TSN QoS information (i.e. priority, delay, maximum TSC Burst Size and Maximum Flow Bitrate) and TSC Assistance Container based on the received configuration information of 5GS Bridge from the CNC as defined in clause 5.28.2 of TS 23.501, the bridge delay information at the TSN AF and the UE-DS-TT Residence time.
The TSN AF provides the Flow Descriptions (including Ethernet Packet Filters), TSC Assistance Container (as described in clause 5.27.2.2 of TS 23.501), and the related QoS information to the PCF by setting up an AF session with required QoS as described in clause 6.1.3.22. In addition, the TSN AF may provide the following parameters to the PCF:
  • Port Management Information Container and related Port number as applicable;
  • User plane node Management Information Container.
The PCF assigns the ARP to a value preconfigured for TSN services.
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6.1.3.23a  Support of Time Sensitive Communication and Time Synchronization |R17|Word‑p. 79

Enablers for Time Sensitive Communication and Time Synchronization are defined in TS 23.501, clause 5.27.
In the case of integration with IEEE TSN network, the TSN AF interacts with the PCF as described in clause 6.1.3.23.
When the PCF has the 5GS Bridge information for the PDU Session received from SMF and has a subscription for the 5GS Bridge information Notification from the TSCTSF or the PCF determines that the PDU Session is potentially impacted by (g)PTP based time synchronization service based on a local policy, if integration with IEEE TSN does not apply, the PCF provides the following parameters to the TSCTSF:
  • 5GS user-plane Node information:
    • 5GS Bridge ID;
    • UE-DS-TT Residence time;
    • port number of the DS-TT;
    • MAC address of the Ethernet port of DS-TT (i.e. DS-TT port MAC address) (for Ethernet type PDU Session), or IP address of the UE (for IP type PDU Session, additionally DNN and S-NSSAI of IP type PDU Session in the case of private IPv4 address being used for the PDU Session);
    • Port Management Information Container and the related port number;
  • User plane node Management Information Container.
Upon reception of the above information, if the TSCTSF does not have a corresponding AF session, the TSCTSF shall create an AF session with the PCF.
The TSCTSF may receive a request from an AF that a data session to a UE is to be set up for Time Synchronization and/or for Time Sensitive Communication with a specific QoS and parameters that describe the traffic characteristics. If so, the TSCTSF provides the Flow Descriptions, the TSC Assistance Container (as described in clause 5.27.2.3 of TS 23.501), and the related QoS information to the PCF by setting up an AF session with required QoS as described in clause 6.1.3.22. In addition, the TSCTSF may provide the following parameters to the PCF:
  • Port Management Information Container and related Port number as applicable.
  • User plane node Management Information Container.
The TSCTSF may use the PTP Port state of NW-TT and DS-TT in the Port/User plane node Management Information Container to determine the Port Pairs that will be used for (g)PTP delivery. Based on this the TSCTSF may request appropriate QoS treatment for the (g)PTP flows from PCF.
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6.1.3.24  Policy control for redundant PDU Sessions |R16|Word‑p. 79

As specified in clause 5.33.2.1 of TS 23.501, in order to support highly reliable URLLC services, two redundant PDU Sessions over the 5G network may be established such that the 5GS sets up the user plane paths of the two redundant PDU Sessions to be disjoint. The Policy control for redundant PDU Session specifies that the PCF may request traffic redundancy for the PDU Session (e.g. when some of the allowed services require redundancy).
The PCF provides to the SMF the indication on whether the PDU Session is a redundant PDU Session or not based on operator policies. The SMF follows the procedure defined in TS 23.501 to establish redundant PDU Sessions depending on the indication from the PCF.
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6.1.3.25  User Plane Remote Provisioning of UE SNPN Credentials in Onboarding Network |R17|Word‑p. 80

User Plane Remote Provisioning of UE SNPN Credentials in Onboarding Network is specified in clause 5.30.2.10.4 of TS 23.501.
User Plane Remote Provisioning of UE SNPN Credentials is provided through a DNN and S-NSSAI used for onboarding.
For a PDU Session with a DNN and S-NSSAI used for onboarding, the PCF may make authorization and policy decisions that restrict the use of the PDU Session, e.g. by restricting the traffic to/from Provisioning Server address(es) and DNS server address(es) only.
For a PDU Session established to the DNN and S-NSSAI used for onboarding, the SMF provides the Onboarding Indication to the PCF if the Onboarding Network is an ON-SNPN or the SMF does not provide any Onboarding Indication to the PCF if the Onboarding Network is a PLMN or an SNPN. When the Onboarding Indication is provided, the PCF does not perform a subscription check. Instead, the PCF uses the locally stored Onboarding Configuration Data for this DNN and S-NSSAI combination to make authorization and policy decisions. When the Onboarding Indication is not provided, the PCF retrieves policy control subscription profile for this SUPI, DNN, S-NSSAI from UDR that includes the list of allowed services. If the list of allowed services includes both PVS and DNS services, then the PCF has local policies that define the PVS and DNS addresses(es) to be used in the SDF template of the PCC Rule(s) and allow traffic to/from these destinations.
If the Onboarding Indication is provided by the SMF, the PCF sets the SDF template of the PCC rule(s) according to the Onboarding Configuration Data for this DNN and S-NSSAI combination that may include the Provisioning Server address(es) and DNS server address(es). If the PCF receives Provisioning Server address(es) from SMF, then PCF creates the SDF templates in the PCC rule using the received Provisioning Server address(es) instead of using the Provisioning Server address(es) stored locally as part of the Onboarding Configuration Data. The Provisioning Server address(es) provided by SMF may include IP address(es) and FQDN(s).
The PCC Rule Authorization function selects QoS parameters applicable to the User Plane Remote Provisioning. Then, the PCF installs these PCC Rules at the SMF to enable traffic to/from the dedicated IP addresses (i.e. Provisioning Server address(es) and DNS server address(es)) with the associated QoS. The DNS server address(es) are locally configured at the PCF.
The PCC Rules provided by the PCF take precedence over the locally stored policy used for the PDU Session used for User Plane Remote Provisioning at the SMF.
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6.1.4  Network slice related policy control |R17|Word‑p. 80

6.1.4.1  GeneralWord‑p. 80

Network slice related policy control supports limitation of the data rate per network slice.
A Maximum Slice Data Rate can be configured for an S-NSSAI (indicating the network slice subject to network slice data rate limitation control) by the operator (e.g. based on an SLA related to the network slice). The Maximum Slice Data Rate has an UL and a DL value.
The Maximum Slice Data Rate defines the maximum allowed aggregate data rate across all GBR and Non-GBR QoS Flows within the network slice identified by an S-NSSAI.
The PCF monitors the data rate of the network slice and ensures that it does not exceed the Maximum Slice Data Rate for that network slice by e.g. rejecting new SM Policy Associations, rejecting new GBR service data flows with high GBR requirements, changing the Authorized Session-AMBR values (if allowed by the HPLMN), changing the MBR values in PCC rules belonging to GBR service data flows or other actions depending on operator policies. When the PCF rejects the SM Policy Association Establishment procedure to the SMF due to the Maximum Slice Data Rate for that network slice is exceeded, then the SMF rejects the establishment of the PDU Session.
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6.1.4.2  Limitation of data rate per network slice with assistance of the NWDAFWord‑p. 81

If the NWDAF is used for network slice data rate analysis, the PCF consumes the analytics from the NWDAF and receives the Data Volume Dispersion Analytics statistics outputs for all UEs of the network slice as defined in TS 23.288. The PCF subscribes to the NWDAF for periodic reporting when it becomes responsible for the first PDU Session of a slice (subject to limitation of data rate per network slice) and cancels the subscription when it stops to handle the last PDU Session of that slice.
The NWDAF periodically provides the analytics output to the PCF. The PCF calculates the utilized data rate of the network slice by using the statistics output Data volume dispersed and Duration. When the utilized data rate of the network slice is getting close to or is exceeding the Maximum Slice Data Rate for this S-NSSAI obtained from the UDR, based on operator policy, the PCF may apply a policy decision to strengthen the traffic restrictions for individual PDU Sessions or PCC rules (see clause 6.1.4.1). When the utilized data rate of the network slice falls below the Maximum Slice Data Rate, the PCF may relax the traffic restrictions for individual PDU Sessions or PCC rules.
When multiple PCFs for the same S-NSSAI are deployed, each PCF subscribes to the analytics from the NWDAF separately.
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6.1.4.3  Limitation of data rate per network slice with PCF based monitoringWord‑p. 81

If the NWDAF is not deployed or is not to be used for network slice data rate analysis, the UDR maintains the Remaining Maximum Slice Data Rate per S-NSSAI and the PCF interacts with the UDR to deduct the value of the authorized Session-AMBR and the MBR of every GBR SDF from the Remaining Maximum Slice Data Rate per S-NSSAI for every PDU Session of this slice. When the remaining data rate for that S-NSSAI is close to zero, the PCF may, based on operator policies, apply a policy decision to strengthen the traffic restrictions for individual PDU Sessions or PCC rules (see clause 6.1.4.1). When the Remaining Maximum Slice Data Rate for that S-NSSAI increases again, the PCF may relax the traffic restrictions for individual PDU Sessions or PCC rules.
The details on monitoring the data rate per network slice by the PCF are described in clause 6.2.1.10.
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