P.8 3GPP HNB Procedures – CS Support

23.2033GPPPolicy and charging control architectureRelease 17TS

P.8.1 S9a CS Session Establishment

Figure P.8.1-1: S9a CS Session Establishment

This procedure is applicable to HNB for QoS enforcement for CS services.

1) S15 session establishment procedure is performed, which can be referred to step 4-5, clause 9.4.1, TS 23.139 [29].

2) The (v-)PCRF initiates Gateway Control Session Establishment procedure with BPCF. The description of this step is the same as steps (A) in clause P.7.2.1.

P.8.2 PCRF initiated S9a CS Session Modification

Figure P.8.2-1: PCRF initiated S9a CS Session Modification

This procedure is performed when the first UE or a subsequent UE connected to a HNB requesting a CS call.

1) The HNB GW sends the S15 session modification message to the PCRF, which can be referred to clause 9.4.2, step3 of TS 23.139 [29].

2) The PCRF (V-PCRF) initiates the Gateway Control and QoS Rules Provisioning procedure to the BPCF as described in step from A.1 to A.2 in clause P.7.4.2.

3) The remaining steps are the same as for clause 9.4.2, steps 5-7 of TS 23.139 [29].

P.8.2A BPCF initiated S9a CS Session Modification

Figure P.8.2A-1: BPCF initiated S9a CS Session Modification

1) This step shows PCC signalling to report QoS Rule failure to (v)PCRF for the CS traffic.

NOTE: Whether additional condition and criteria specific for BBF network and defined by BBF forum are applicable for trigger BPCF-Initiated S9a CS Session Modification is out of the scope of 3GPP definition.

The BPCF initiates Gateway Control and QoS Rule Request to report QoS Rule failure to (v)PCRF. The request includes a report identifying the QoS Rules that failed and a reason. The (v)PCRF acknowledges the request.

2) The (v)PCRF sends the S15 session modification request message to the HNB GW. The (v)PCRF includes the report identifying the QoS Rules that failed and a reason derived from the BPCF. The BPCF response the S15 session modification to the (v)PCRF, which is according to TS 23.139 [29].

P.8.3 S9a CS Session Termination

Figure P.8.3-1: S9a CS Session Termination

1) The HNB GW sends a S15 session termination request to the to (v-)PCRF and then the (v-)PCRF acknowledges the request. This can be referred to clause 9.4.3, step 2 of TS 23.139 [29].

2) The PCRF (V-PCRF) initiated the GW control session termination as defined in steps 2 and 3 in clause P.7.3.2.

Annex Q (informative):
How to achieve Usage Monitoring via the OCS

An alternative to providing the usage monitoring feature described in this technical specification is to re-use the capabilities defined in 3GPP Release 11 for implementation of Policy Control based on Subscriber Spending Limits when online charging is also performed.

There are two ways defined in this Annex to achieve usage monitoring via OCS:

If PCC/ADC rules that are subject to usage monitoring share the same charging key, the same measurement methods then the Usage Reports over Gy are used for both charging and usage monitoring, and in addition:

– Policy Counter Status values are associated with the quota allocated with Charging Keys are configured in the OCS. Policy Counter Status (INQUOTA, OUTQUOTA) changes trigger notifications over Sy.

– The PCRF is configured with operator policies that associate the policy counter status to a policy decision e.g. block or allow a service to a QoS.

If PCC/ADC rules that are subject to usage monitoring have different charging keys and/or different measurement methods then to achieve a common usage report over Gy then:

– A common Charging Key is used for all services that are subject to usage monitoring. The charging control information of the PCC/ADC rules includes that online charging applies, the common charging key for the service and service level reporting is activated. In addition, the measurement method is to be set to time/volume.

– Policy Counter Status values associated with the quota allocated with Service identifier is configured in the OCS. Policy Counter Status (INQUOTA, OUTQUOTA) changes trigger notifications over Sy.

– The PCRF is configured with operator policies that associate the policy counter status to a policy decision e.g. block or allow a service to a QoS.

Figure Q.1-1: Deployment for Usage Monitoring via Online Charging System

Annex R (informative):
Disabling/re-enabling Usage Monitoring for a PCC/ADC rule

If usage monitoring for a PCC/ADC rule (belonging to a usage monitoring group) needs to be disabled, one of the two ways below can be chosen to realize this feature:

– The PCRF generates a new PCC/ADC rule with the same information (apart from the PCC/ADC Rule identifier) as the existing PCC/ADC rule used to control the same traffic but without the monitoring key. The PCRF provides the new PCC/ADC rule to the PCEF/TDF and removes the existing PCC/ADC rule.

NOTE 1: It is assumed that the activation of the new PCC/ADC rule takes place at the same time as the removal of the existing PCC/ADC rule and that no other actions are triggered (e.g. with respect to charging and bearer management) beside the ones related to the disabling of usage monitoring.

– The operator selects a specific monitoring key value to be used for all PCC/ADC rules for which usage monitoring is disabled. The PCRF modifies the monitoring key of the corresponding PCC/ADC rule to this specific value. Following the PCRF instruction, the PCEF or TDF updates the monitoring key in the modified PCC/ADC rule and collects the usage information for the specific monitoring key value. The PCEF/TDF usage reports would still be received by the PCRF but could be ignored.

NOTE 2: The operator should configure the usage threshold to a sufficiently high value so that frequent usage reports are avoided.

If usage monitoring needs to be re-enabled for a PCC/ADC rule (i.e. usage monitoring has been disabled for this PCC/ADC rule before), one of the two ways below can be chosen to realize this feature:

– The PCRF generates a new PCC/ADC rule with the same information (apart from the PCC/ADC Rule identifier) as the existing PCC/ADC rule used to control the same traffic and adds the required monitoring key. The PCRF provides the new PCC/ADC rule to the PCEF/TDF and removes the existing PCC/ADC rule without monitoring key. The PCEF/TDF executes the operations in the same way it is described above in Note 1.

– The PCRF modifies the monitoring key of the corresponding PCC/ADC rule to the value of the required usage monitoring group (e.g. back to its original value).

Annex S (normative):
Fixed Broadband Access