Telecom billing transformation in the 5G era
The deployment of 5G networks and dynamic slicing requires telecom operators to transition from monolithic billing systems to modular, API-first architectures. Legacy systems cannot charge for traffic in real time. Furthermore, according to the CFCA Global Fraud Loss Survey 2025, global telecom fraud losses reach $41.82 billion annually, forcing operators to integrate charging, mediation, and anti-fraud as microservices.
The role of mediation and real-time charging
Telecom mediation platforms bridge legacy protocols (SS7, Diameter) and the cloud-native 5G core operating via HTTP/2 REST APIs. In 5G networks, the Charging Function (CHF) interacts with the Session Management Function (SMF) via the Nchf interface. This enables real-time balance deductions based on Quality of Service (QoS) parameters and prevents bad debt.
Fraud prevention and integration solutions
The lack of real-time control leaves operators vulnerable to International Revenue Share Fraud (IRSF). Protection requires signaling analysis combined with BSS. To build custom API layers on top of legacy systems, developers use modern low-code platforms like UnityBase, which ensure secure data exchange through built-in audit and access control mechanisms.
Transitioning to Open Digital Architecture (ODA)
The TM Forum's ODA industry standard involves replacing proprietary BSS/OSS with microservices interacting via open APIs. The following approach is recommended for decomposing the monolith:
- Product catalog centralization: creating a single source of truth for tariffs.
- API Gateway: deploying a gateway to protect microservices.
- Strangler Fig Pattern: gradually migrating subscribers to the new charging system.
What is at stake for the industry
Legacy billing systems prevent telecom operators from monetizing 5G slicing and real-time Quality of Service (QoS). This technological gap, combined with the lack of real-time control, exposes businesses to severe financial risks, including International Revenue Share Fraud (IRSF) and a share of the $41.82 billion annual global telecom fraud losses.
Action plan
To modernize billing systems and secure revenue, operators and developers should adopt the following practical steps:
- Implement real-time mediation: Use the Charging Function (CHF) interacting with the Session Management Function (SMF) via the Nchf interface to enable real-time balance deductions and prevent bad debt.
- Deploy low-code integration layers: Build custom API layers on top of legacy systems using platforms like UnityBase to ensure secure data exchange through built-in audit and access control.
- Adopt Open Digital Architecture (ODA): Decompose the monolith by centralizing the product catalog, deploying an API Gateway, and migrating subscribers gradually using the Strangler Fig Pattern.
Prepared by a Software Ukraine member. Original publication.