When a new PDU Session is established, based on local configuration associated with the DNN/S-NSSAI, the PCF determines if the PDU Session needs involvement of TSCTSF. If the TSCTSF is used the PCF invokes Npcf_PolicyAuthorization_Notify service operation to the TSCTSF discovered and selected as described in clause 6.3.24 of TS 23.501. The Npcf_PolicyAuthorization_Notify service operation includes the UE address of the PDU Session and DNN/S-NSSAI. If the TSCTSF is not used, the PCF subscribes to notifications for Application Data from UDR.
The PCF registers to BSF as described in TS 23.503. When the TSCTSF is used, the TSCTSF invokes a Npcf_PolicyAuthorization_Create request message to the PCF and stores the DNN, S-NSSAI and IP address as received from PCF and SUPI as received from BSF and associates them with the AF-session.
The AF sends a request to reserve resources using Nnef_AF_Request_QoS_Create request message (GPSI or External Group ID, AF Identifier, Flow description(s) or External Application Identifier, QoS reference or individual QoS parameters, Alternative Service Requirements (as described in clause 126.96.36.199 of TS 23.503), DNN, S-NSSAI) to the NEF. Optionally, a period of time or a traffic volume for the requested QoS can be included in the AF request. The AF may, instead of a QoS Reference, provide the individual QoS parameters. Regardless, whether the AF request is formulated using a QoS Reference or Individual QoS paramaters, the AF may also provide one or more of the parameters that describe the traffic characteristics as described in clause 188.8.131.52 or 184.108.40.206a of TS 23.503. 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 220.127.116.11 of TS 23.503.
This step is the same as steps 2-4 in clause 18.104.22.168.
The NEF determines whether to invoke the TSCTSF or not, as described in step 3 in clause 22.214.171.124. If the NEF determines to invoke TSCTSF, steps 4-9 are executed and steps 10-12 are skipped. Otherwise steps 4-9 are skipped and steps 10-12 are executed. The procedure then continues in step 13.
The TSCTSF determines the individual group members using Nudm SDM Group Identifier translation service. The TSCTSF also determines which of these group members have active PDU Sessions matching the DNN/S-NSSAI and determines the relevant UE address. The TSCTSF manages the AF request QoS information targeting for a group as defined in TS 23.501.
If the NEF determines to not invoke the TSCTSF, the NEF uses the Nudr_DM service to store the information related to the Internal Group ID or SUPI in UDR. The information is stored as Application Data in UDR. If the AF requested for notifications of Resource allocation status or other events, the NEF includes the information required for reporting the event, including the Notification Target Address pointing to the NEF or AF and the Notification Correlation ID containing the AF Transaction Internal ID.
When an event condition is met, e.g. that the establishment of the transmission resources corresponding to the QoS update succeeded or failed, the PCF sends a notification to TSCTSF or NEF as applicable. This step is the same as steps 7-8 in clause 126.96.36.199.
This clause contains the detailed description and the procedures for the network status reporting capability.
An AF may request for being notified about the network status, in a specific geographical area or for a specific UE.
The following methods are supported:
The AF requests to be informed, one-time, about the network status. This procedure is referred to as one-time network status request;
The AF requests to be informed, continuously, about the network status. This procedure is referred to as continuous network status request;
The procedure as described in clause 188.8.131.52 or clause 184.108.40.206 of TS 23.288 is used by an AF to retrieve Network Status Result (NSR) from the network for a specific geographical area or for a specific UE.
After receiving the request for network status notification from the AF, the NEF retrieves user data congestion analytics information from NWDAF, as defined in TS 23.288.
Based on the user data congestion analytics information the NEF receives from the NWDAF, the NEF derives and reports the network status for the geographical area or for the UE as Network Status Result (NSR) to the AF. When reporting to the AF, the NSR shall not include any 3GPP location information.
When an AF requests one-time Network Status from the NEF, the NEF can optionally provide a time interval at which the AF is allowed to re-issue the same request for network status.