4.2.5 Npcf_SMPolicyControl_Delete Service Operation

29.5123GPP5G SystemRelease 18Session Management Policy Control ServiceStage 3TS

Tools: ARFCN - Frequency Conversion for 5G NR/LTE/UMTS/GSM

4.2.5.1 General

The delete service operation provides means for the NF service consumer to delete the policy context associated with a PDU Session.

The following procedures using the Npcf_SMPolicyControl_Delete service operation are supported:

– Deletion of the policy context associated with a PDU session.

– Report Accumulated Usage.

– Report Access Network Information.

– Report Service Data Flow QoS Monitoring.

– Network slice related data rate policy control.

4.2.5.2 SM Policy Association termination

Figure 4.2.5.2-1: SM Policy Association termination

When an individual resource of the SM Policy Association collection shall be deleted, the NF service consumer shall invoke the Npcf_SMPolicyControl_Delete service operation towards the PCF using an HTTP POST request, as shown in figure 4.2.5.2-1, step 1.

The NF service consumer shall set the request URI to "{apiRoot}/npcf-smpolicycontrol/v1/sm-policies/{smPolicyId}/delete". The {smPolicyId} in the URI identifies the "Individual SM Policy" to be deleted.

The HTTP POST request sent by the NF service consumer (e.g. SMF) shall contain (if available) the SM Policy Association related information within the SmPolicyDeleteData data structure in the request body:

– accumulated usage within the "accuUsageReports" attribute as defined in clause 4.2.5.3;

– the user location(s) information within the "userLocationInfo" attribute, the information on when the UE was last known to be in that location within the "userLocationInfoTime" attribute, the PLMN Identifier or the SNPN Identifier (the PLMN Identifier and the NID) within the "servingNetwork" attribute, the timezone information within the "ueTimeZone" attribute and the RAN and/or NAS release cause(s) within the "ranNasRelCauses" attribute as defined in clause 4.2.5.4;

NOTE 1: The SMF derives the value of the "userLocationInfoTime" attribute from the age of location information received from the AMF at PDU session termination as described in 3GPP TS 29.502[22]. Whether the "userLocationInfo" attribute also encodes the age of location is implementation specific.

NOTE 2: The SMF encodes both 3GPP and non-3GPP access UE location in the "userLocationInfo" attribute when they are both received from the AMF.

– the "PS_TO_CS_HO" value within the "pduSessRelCause" attribute, if the PDU session is released due to PS to CS handover and the "PDUSessionRelCause" feature defined in clause 5.8 is supported;

– one or more QoS Monitoring report(s) within the "qosMonReports" attribute, as defined in clause 4.2.5.5;

– the "RULE_ERROR" value within the "pduSessRelCause" attribute, if the PDU session is released due to a failed enforcement of the applied session rule as described in clause 4.2.4.21 and the "ImmediateTermination" feature defined in clause 5.8 is supported.

When the PCF receives the HTTP POST request from the NF service consumer and if the PCF successfully processed and accepted the received HTTP POST request from the NF service consumer, the PCF shall acknowledges the request by sending an HTTP response message with the corresponding status code. The PCF acknowledges the delete request by sending a "204 No Content" response to the NF service consumer, as shown in figure 4.2.5.2-1, step 2. Further, the PCF shall remove the individual resource linked to the delete request.

If errors occur when processing the HTTP POST request, the PCF shall send an HTTP error response as specified in clause 5.7.

If the feature "ES3XX" is supported, and the PCF determines the received HTTP POST request needs to be redirected, the PCF shall send an HTTP redirect response as specified in clause 6.10.9 of 3GPP TS 29.500 [4].

4.2.5.3 Report Accumulated Usage

If the UMC feature is supported, at PDU session termination, the SMF shall send the accumulated usage information for all the monitoring keys for which usage monitoring was previously enabled. When the SMF receives the accumulated usage report from the UPF as defined in clause 7.5.7.2 of 3GPP TS 29.244 [13], the SMF shall include one or more received accumulated usage reports in the "accuUsageReports" attribute of the SmPolicyDeleteData data structure.

If all PDU sessions related to the same DNN and S-NSSAI combination for a user are terminated, the PCF shall store the remaining allowed usage, i.e. the information about the remaining overall amount of resources, in the UDR as defined in 3GPP TS 29.519 [15].

4.2.5.4 Report Access Network Information

If the RAN-NAS-Cause feature is supported or the NetLoc feature is supported, within the SmPolicyDeleteData data structure, the SMF shall provide the available access network information within the "userLocationInfo" attribute (if available), the information on when the UE was last known to be in that location within the "userLocationInfoTime" attribute (if available), the "ueTimezone" attribute (if available). Additionally, for the NetLoc feature, if the user location information is not available, the SMF shall include the PLMN Identifier or the SNPN Identifier (the PLMN Identifier and the NID) within the "servingNetwork" attribute; for RAN-NAS-Cause feature, if the SMF received from the access network the RAN cause and/or the NAS cause due to PDU session termination, the SMF shall provide the received cause(s) in the "ranNasRelCauses" attribute.

NOTE 1: The SMF derives the value of the "userLocationInfoTime" attribute from the age of location information received in the Location-Report (defined in clause 5.3.1 of 3GPP TS 29.518 [36]) from the AMF. Whether the "userLocationInfo" attribute also encodes the age of location is implementation specific.

NOTE 2: The SMF encodes both 3GPP and non-3GPP access UE location in the "userLocationInfo" attribute when they are both received from the AMF.

4.2.5.5 Report Service Data Flow QoS Monitoring

If the QosMonitoring feature is supported, when the SMF receives from the UPF the information about any one of the following items for one or more SDF(s) as defined in clause 5.24.4.3 of 3GPP TS 29.244 [13]:

– uplink packet delay(s); or

– downlink packet delay(s); or

– round trip delay(s);

and the "QOS_MONITORING" policy control request trigger was provisioned, then within the SmPolicyDeleteData data structure, the SMF shall include one or more Qos Monitoring report(s) within the "qosMonReports" attribute. In each QosMonitoringReport data structure, the PCF shall include:

– one or two uplink packet delay(s) within the "ulDelays" attribute; or

– one or two downlink packet delay(s) within the "dlDelays" attribute; or

– one or two round trip packet delay(s) within the "rtDelays" attribute; and

– the affected PCC rule identifiers within the "refPccRuleIds" attribute.

4.2.5.6 Network slice related data rate policy control

When an Npcf_SMPolicyControl_Delete request is received, the PCF may check if the S-NSSAI to which the received request relates is subject to network slice data rate policy control. If it is the case, the PCF shall apply network slice data rate control as described in clause 4.2.6.8.