Hi Tom,
Should have added a point regarding IN – Intelligent Network – that is used for Realtime Prepaid Charging.
Thanks to the open source community, cloud native environment, etc.. we now have an open source Online Charging System (3GPP OCS).
Good example is SigScale. This can be used and integrated with the 5G Core. Cloud Data Centers (AWS/ GCP / AZURE / etc..) and Containers / Virtual Machines and MANO (ETSI) / ONAP are key enablers.
https://github.com/sigscale/ocs
Supported Use-Cases:
Use cases include 3GPP PS data, CS voice, SMS and IMS voice (VoLTE) as well as wireline DSL and WiFi. Supports 3GPP DIAMETER Ro (e.g. S-GW, SGSN, MSC, SMSC, IMS-AS, BRAS) and RADIUS (e.g. WiFi Access Point).
Reference:
VBR/ Wallis Dudhnath