According to the Ericsson Mobility Report (November 2025), the number of 5G subscriptions worldwide will reach 6.4 billion by 2031. This trend is accompanied by the massive adoption of IoT, which places extreme pressure on existing billing systems. Legacy architectures, which have been the foundation of telecom infrastructure for decades, often become bottlenecks as they are not designed for the event generation frequency inherent to IoT.
Why monolithic BSS systems hinder 5G ecosystems
The problem with monolithic BSS lies in the mixing of signal processing logic and financial calculations. In scenarios involving massive machine-type communications (mMTC) or high-frequency heartbeat signals, the billing core is forced to process millions of records (CDR) every hour. This leads to high latency in rating and limits the ability of operators to implement dynamic tariff plans.
Mediation layer as an architectural buffer
In accordance with the principles of the TM Forum Open Digital Architecture (ODA), an effective approach is the transition to a component-based architecture. Implementing an intermediate mediation layer allows for the normalization and aggregation of data before it reaches the financial core. This offloads the BSS, allowing it to focus on financial transactions rather than primary event stream processing.
Fraud prevention and processing speed
According to the CFCA Global Fraud Loss Survey 2025, global losses from telecom fraud are estimated at 41.82 billion dollars. A modular architecture, where the mediation layer operates in real-time, allows for the implementation of control policies significantly faster than monolithic systems.
Modernization strategy without business disruption
Replacing legacy billing entirely is a complex task. A more rational strategy is decoupling through the implementation of specialized modules. For example, DooxSwitch can be used as a mediation solution to offload the SIP core and integrate via API with financial systems. If the billing core or auxiliary services require flexible integration, solutions can be built on the UnityBase platform, which provides tools for API creation, metadata management, and security (RLS/ACL) essential for modern enterprise systems.
| Readiness level | Architectural approach | Characteristics |
|---|---|---|
| Level 1 (Legacy) | Monolithic architecture | Event processing directly in the core, high latency |
| Level 2 (Hybrid) | External mediation layer | CDR aggregation, partial core offloading |
| Level 3 (ODA-compliant) | Component architecture | API-first interaction, real-time billing via microservices |
FAQ
How does a mediation layer affect the speed of implementing new IoT tariffs?
It allows for changing tariff logic at the mediation level, minimizing the need for risky changes in the financial core (BSS).
What are the technical requirements for integrating a mediation system with an existing BSS?
Key requirements include support for standard APIs (REST/SOAP), asynchronous data processing, and ensuring message integrity during transmission.
How can data loss be avoided when transitioning from monolithic billing to a modular architecture?
It is necessary to implement a parallel data processing stage (shadow billing) and use integrity verification mechanisms (audit trail) at each integration stage.