How it Works

The SMF requests the policy information from PCF. The PCF in turn provides the policy rules during and after PDU session creation to enable the dynamic policy application. Dynamic policy management involves the following operations:

  • Policy Context Creation: This operation is performed at the time of PDU session create and the PCF sends the PCC rules and the associated QoS, Charging and other policy data in the response message.

  • Policy Context Update: For any RAN-initiated or UE-initiated policy updates and for notification of trigger events, the SMF initiates a policy context update. In response, the PCF sends the changed policy data that impacts the QoS and charging.

  • Policy Context Update Notification: During the lifecycle of a PDU session, the PCF can initiate a policy update based on interaction with the AF or local configuration changes at PCF. The SMF handles the updated policy rules when received in a notification from the PCF.

  • Policy Context Delete: At the end of a PDU session, the SMF terminates the Policy Context with PCF.

The following figure illustrates the dynamic policy management procedure for a PDU session.

Dynamic Policy Management Call Flow