Section: 4.15.6.13.2 Procedures for Creating a Multi-member AF session with required QoS
Content: Figure 4.15.6.13.2-1: Procedures for creating a Multi-member AF session with required QoS 1. The AF sends a request to reserve resources for the traffic flows for the communication between a set of UEs and an AF, using Nnef_AFsessionWithQoS_Create request message (a list of UE addresses, AF Identifier, Flow description information or External Application Identifier, QoS Reference or individual QoS parameters, Alternative Service Requirements (as described in clause 6.1.3.22 of TS 23.503[ Policy and charging control framework for the 5G System (5GS); Stage 2 ]  [20]), QoS parameter(s) to be measured, Reporting frequency, Target of reporting, optional an indication of local event notification, DNN, S-NSSAI) to the NEF. The Flow description information, if provided, is common for the list of UEs identified by the list of UE addresses. - The AF may, instead of a QoS Reference, provide one or more of the following individual QoS parameters: Requested 5GS Delay (optional), Requested Priority (optional), Requested Guaranteed Bitrate, Requested Maximum Bitrate, Maximum Burst Size and Requested Packet Error Rate. The optional Alternative Service Requirements provided by the AF shall either contain QoS References or Requested Alternative QoS Parameter Set(s) in a prioritized order as described in clause 6.1.3.22 of TS 23.503[ Policy and charging control framework for the 5G System (5GS); Stage 2 ]  [20]. The AF may provide QoS parameter(s) to be measured as defined in clause 5.45 of TS 23.501[ System architecture for the 5G System (5GS) ]  [2], Reporting frequency, Target of reporting, optional an indication of local event notification as described in clause 6.1.3.21 of TS 23.503[ Policy and charging control framework for the 5G System (5GS); Stage 2 ]  [20]. The AF may also provide the Consolidated Data Rate threshold and optionally, a list of UE addresses subject to Consolidated Data Rate monitoring. If so, the AF shall also subscribe to QoS Monitoring of UL and/or DL data rate described in clause 5.45 of TS 23.501[ System architecture for the 5G System (5GS) ]  [2] . NOTE 1: When the Consolidated Data Rate threshold is provided, it, by default, applies to the list of UE addresses associated with the Multi-member AF session with required QoS. However, if the specific list of UE addresses subject to Consolidated Data Rate monitoring is also provided together with the Consolidate Data Rate threshold, then such list has to be the subset of the list of UE addresses. 2. The NEF authorizes the AF request that contains a list of UE addresses and may apply policies to control the overall amount of QoS authorized for the AF. If the authorisation is not granted, all steps (except step 8) are skipped and the NEF replies to the AF with a Result value indicating that the authorisation failed. The NEF assigns a Transaction Reference ID to the Nnef_AFsessionWithQoS_Create request. The NEF activates Consolidated Data Rate monitoring only when both the Consolidated Data Rate threshold and a request to do QoS Monitoring of data rate are provided by the AF. 2a. If the NEF recognizes, based on configuration, that the IP address(es) received in the list of UE addresses are different from the IP address(es) assigned by 5GC (i.e. the UE(s) are behind a NAT in UPFs), the NEF performs steps 3 to 6 of the AF specific UE ID retrieval procedure defined in clause 4.15.10 for each UE IP address with port number in order to identify the corresponding IP address (and IP domain, if necessary) that has been assigned by the 5GC. The NEF then uses the respective corresponding IP address (and IP domain, if necessary) in the following steps instead of the UE IP address provided by the AF. 3-4. The NEF finds BSF serving the UE IP address(es) using NRF and then for each UE IP address, the NEF uses Nbsf_Management_Discovery service operation, providing the UE IP address, to discover the responsible PCF for each of the PDU Sessions. Steps 5-7 apply for each UE address in the list of UE addresses. 5. The NEF provides the UE address and the received parameters in step 1 to the PCF in the Npcf_PolicyAuthorization_Create request. If the request contains QoS monitoring information without an indication of direct event notification, the NEF shall include that indication in the request to ensure that QoS Monitoring reports shall be sent by the UPF directly to the NEF. 6. Step 4 in Figure 4.15.6.6-1 applies. The PCF generates authorized QoS Monitoring policy according to the QoS Monitoring information if received from the NEF in step 5 and provides PCC rules with the policy to the SMF as described in clause 6.1.3.21 of TS 23.503[ Policy and charging control framework for the 5G System (5GS); Stage 2 ]  [20]. The SMF configures the UPF to perform QoS Monitoring as described in clause 5.8.2.18 of TS 23.501[ System architecture for the 5G System (5GS) ]  [2]. 7. The PCF sends the Npcf_PolicyAuthorization_Create response message to the NEF. 8. The NEF aggregates the authorization responses from the PCFs and sends a Nnef_AFsessionWithQoS_Create response message (Transaction Reference ID, Result for list of UE addresses) with the aggregated authorization responses to the AF. Result for list of UE addresses includes whether the authorization was successful or has failed for every UE address in the list. The NEF stores the list of UE addresses for which the authorization was successful together with the Transaction Reference ID, the QoS and the QoS monitoring information. Steps 9-10 apply for each UE address in the list of UE addresses. 9. Step 6 in Figure 4.15.6.6-1 applies. 10. Step 7 in Figure 4.15.6.6-1 applies. 11. The NEF aggregates the notifications from the PCFs and sends a Nnef_AFsessionWithQoS_Notify message (Transaction Reference ID, Result for list of UE addresses) with the aggregated resource allocation status events to the AF. Result for list of UE addresses includes, for every UE address in the list, the information whether resources are allocated, resources are not allocated or resources are allocated while the currently fulfilled QoS matches an Alternative Service Requirement. The NEF updates the locally stored list of UE addresses by removing any UEs for which resources could not be allocated. NOTE 2: For those UE address(es) that did not get any resources, the AF may request resource reservation again, by adding them to the list of UE address(es) as described in clause 4.15.6.13.3. 12. As direct event notification is requested based on the parameters received in step 5, the QoS Monitoring events are reported by the UPF(s) to the NEF using Nupf_EventExposure service as described in clause 5.2.26.2. 13. When the NEF receives QoS Monitoring events, the NEF sends Nnef_AFsessionWithQoS_Notify message with the individual or aggregated QoS Monitoring events to the AF as described for the QoS Monitoring and the Consolidated Data Rate monitoring in clause 4.15.6.13.1.