Section: 4.16.15.2.2 Procedure for PDTQ warning notification
Content: 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[ Architecture enhancements for 5G System (5GS) to support network data analytics services ]  [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[ Architecture enhancements for 5G System (5GS) to support network data analytics services ]  [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[ Policy and charging control framework for the 5G System (5GS); Stage 2 ]  [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.