E.4.4.2 IP-CAN Session Modification for NSWO traffic

29.2133GPPPolicy and charging control signalling flows and Quality of Service (QoS) parameter mappingRelease 17TS

E.4.4.2.1 PCRF-initiated IP-CAN Session Modification

This procedure is applicable for WLAN scenario.

Figure E.4.4.2.1.1.1: PCRF-Initiated IP-CAN Session Modification for NSWO traffic

1 Step 1 to 3 as specified in figure 4.3.1.1.1 are executed. The H-PCRF receives an internal or external trigger to update PCC Rules for NSWO traffic (e.g. upon a request from the AF, a request from the TDF in the non roaming case or due to operator policies). External trigger in Step 1 in figure 4.3.1.1.1 only applies to AF session interactions (as described in clause 4.3.1.2), TDF session interactions (as described in clause 4.3.1.1) and SPR subscription data modification (as described in clause 4.3.1.1).

NOTE: In the roaming case, the TDF is located in the V-PLMN, upon a request from the TDF, the V-PCRF will proxy the request to the H-PCRF, this may also trigger the PCRF-Initiated IP-CAN Session Modification for NSWO traffic.

2 The H-PCRF sends a Diameter RAR to update the QoS information to the BPCF.

If the UE is roaming, then steps 2a ~ 2c are executed instead of step 2:

2a.:The H-PCRF sends a Diameter RAR to the V-PCRF to install, modify or remove PCC Rules.

2b. The V-PCRF performs local authorization of the received PCC rules when necessary.

2c. The V-PCRF sends a Diameter RAR to the BPCF to update the QoS information.

3 The BPCF shall perform QoS validation and translates the PCC rule as received (i.e. SDF template, QCI, MBR, GBR and ARP) into access specific QoS parameters applicable in the Fixed Broadband Access.

NOTE: The detail of the mapping from 3GPP QoS parameters on S9a to QoS parameters applicable in the Fixed Broadband Access is out of 3GPP scope.

4. The BPCF sends RAA to the H-PCRF to acknowledge the RAR and informs the H-PCRF about the outcome of the PCC rule operation. If the BPCF cannot provide the requested QoS from the PCRF, the BPCF may respond with the acceptable QoS.

If the UE is roaming, then steps 4a ~ 4b are executed instead of step 4:

4a. The BPCF sends RAA to the V-PCRF to acknowledge the RAR and informs the V-PCRF about the outcome of the PCC rule operation. If the BPCF cannot provide the QoS requested by the H-PCRF, the BPCF may respond with the acceptable QoS.

4b. The V-PCRF forwards the RAA to the H-PCRF to acknowledge the RAR and informs the H-PCRF about the outcome of the PCC rule operation.

NOTE: If the H-PCRF is informed that the BPCF cannot provide the requested QoS, the H-PCRF may decide to install, modify or remove PCC rules. In that case, the same flow as described in this clause will be executed.

5. If the AF requested it, the PCRF notifies the AF as described in steps 6-11 in clause 4.3.2.1.1.

E.4.4.2.2 BPCF-initiated IP-CAN Session Modification

This procedure is applicable for WLAN scenario.

Figure E.4.4.2.2.1: BPCF-Initiated IP-CAN Session Modification for NSWO traffic

1. The trigger for this procedure is that the Fixed Broadband Access network has pre-empted some resources and wants to report a PCC rule failure to the PCRF, or when the Fixed Broadband Access network cannot sustain the bandwidth allocated to a particular traffic class/DSCP aggregate.

2. The BPCF sends a Diameter CCR to the H-PCRF with the CC-Request-Type AVP set to the value UPDATE_REQUEST to report PCC Rule failure.

When the UE is roaming, steps 2a ~ 2c are executed instead of step 2:

2a. The BPCF sends a Diameter CCR to the V-PCRF with the CC-Request-Type AVP set to the value UPDATE_REQUEST to report PCC Rule failure.

2b. The V-PCRF stores the information received.

2c. The V-PCRF sends a Diameter CCR to the H-PCRF within the information received in step 2a to report PCC Rule failure. The V-PCRF shall link the S9a* session to S9 session.

3 The H-PCRF sends a Diameter CCA to the BPCF to acknowledge the CCR command.

When the UE is roaming, steps 3a ~ 3b are executed instead of step 3:

3a. The H-PCRF sends a Diameter CCA to the BPCF to acknowledge the CCR command..

3b. The V-PCRF sends a Diameter CCA to the BPCF to acknowledge the CCR command.

4. The PCRF-initiated IP-CAN Session Modification as described in E.4.4.2.1 may take place.