Feature Description

The SMF acts as a Charging Transfer Function (CTF). The CTF generates charging events toward the Charging Function (CHF), which is responsible for generating Charging Data Records (CDRs).

This SMF interacts with various interfaces, such as N40, Gy, N4, N7, and N10, facilitating charging in entirety. SMF uses the Nchf/N40 and OCS/Gy interfaces to generate charging events.

SMF as a Charging Transfer Function

The SMF Charging feature supports the following functionality.

  • Converged Online and Offline charging.

  • PDU session charging using the service-based interface.

  • Network slice instance charging.

  • Charging information collection per PDU session for UEs served under 3GPP and non-3GPP access (untrusted non-3GPP access, trusted non-3GPP access and wireline).

    Note

    OCS charging behaviour is applicable to the SMF 4G session when the SMF configuration has DNN profile with network element profiles for OCS.

  • Unique identity number assignment per PDU session for billing purposes.

  • Separate count of data volumes on both the uplink and downlink directions. The data volumes reflect the data as delivered to and forwarded from the user.

  • Charging mechanism that provides the date and time information when the PDU session starts.

  • Handling of Charging Characteristics specific to a subscription or a subscribed DNN.

  • Identification of data volumes, elapsed time, or events for individual service data flows (flow-based charging). One PCC rule identifies one service data flow.

  • Usage reporting of a service, a detected application per rating group, or per combination of the rating group and service ID. You can activate this reporting level per PCC rule.

  • Quota management only per Rating Group (RG) in case of N40, RG/RG+SID in the case of Gy per PDU session.

  • Charging for IP-based PDU session types.