4.4.3 Gateway Control and QoS Rules Provision

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

Since the PCRF is required to keep QoS rules aligned with the active PCC rules for a certain IP-CAN session, it shall initiate the Gateway Control and QoS Rules Provision whenever there is a change to the corresponding PCC rules for a Gx session that is linked with the Gateway Control Session.

Figure 4.4.3.1: Gateway Control and QoS Rules Provision

1. The H-PCRF receives an internal or external trigger to update QoS Rules and event triggers for a gateway control session. If the trigger is from the AF and the AF requests the access network information, the H-PCRF applies the procedure as defined in clause 4a.5.16 of 3GPP TS 29.212 [9] to request the access network information. If the trigger is from the AF and the AF provided the Sharing-Key-UL AVP and/or Sharing-Key-DL AVP within the Media-Component-Description AVP, the H-PCRF may apply the procedures as defined in clause 4a.5.10.6 of 3GPP TS 29.212 [9] to request the resource sharing.

2. The H-PCRF sends a Diameter RAR to request that the BBERF installs, modifies or removes QoS Rules and/or updates the event triggers.

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 provision updated QoS Rules and updated event triggers.

For case 2a, the RAR provides the updated QoS Rules and updated event triggers with the information included at command level.

For case 2b, The H-PCRF sends a Diameter RAR to the V-PCRF within the information at Subsession-Decision-Info AVP.

2b. The V-PCRF identifies the gateway control session if needed and performs local authorization of the updated QoS rules when necessary.

2c. The V-PCRF sends a Diameter RAR to the BBERF to provision updated QoS rules and updated event triggers.

3. The BBERF installs, modifies or removes the identified QoS Rules. The BBERF also enforces the authorized QoS and enables or disables service flow according to the flow status of the corresponding QoS Rules.

4. The BBERF sends RAA to the H-PCRF to acknowledge the RAR and informs the H-PCRF about the outcome of the QoS rule operation. If network initiated resource allocation procedures apply for the QoS rules and the corresponding IP-CAN bearer can not be established or modified to satisfy the bearer binding, then the BBERF rejects the activation of a PCC rule.

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

4a. The BBERF sends RAA to the V-PCRF to acknowledge the RAR and informs the V-PCRF about the outcome of the QoS rule operation. If network initiated resource allocation procedures apply for the QoS rules and the corresponding IP-CAN bearer can not be established or modified to satisfy the bearer binding, then the BBERF rejects the activation of a PCC rule.

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 QoS rule operation.

5. If needed, the BBERF initiates the access specific procedures to create or modify existing IP-CAN bearers. When the procedure in step 5 is completed and requires of notifications from the BBERF to the PCRF, e.g. in the case of access network information, the steps described as in clause 4.4.2 are additionally executed.