According to the TM Forum Open Digital Architecture (ODA) 2026 principles, transitioning to a modular, API-first architecture is critical for telecom operators aiming to scale services without overloading legacy BSS/OSS monoliths. Today, implementing new entities, such as specialized IoT device registries or updated subscriber databases, often faces rigid data coupling within billing systems. Any change to the data schema in such a monolith carries high risks to the stability of the entire network.
Monolithic BSS/OSS as a barrier to innovation
The limitations of legacy systems have both architectural and financial-security dimensions. According to the CFCA Global Fraud Loss Survey 2025, global losses from telecom fraud are estimated at 41.82 billion dollars, which is often a consequence of the inability to quickly implement new subscriber verification mechanisms in locked-down monoliths. Furthermore, according to the ENISA Threat Landscape 2025 report, digital infrastructure and services account for a significant portion of data breaches, which highlights the need to move critical data into secure, decomposed components.
ODA ecosystem and decomposition architecture
The architectural transition to service-oriented models, aligned with 3GPP principles for 5G Core, involves separating functions into independent domain components. The "sidecar" pattern allows this to be implemented in practice: low-code components can process requests to subscriber data or IoT registries without changing the core BSS/OSS database schema. Using Domain metadata allows for the automatic generation of REST API, ensuring the compatibility of new modules with Open API standards.
Comparison of registry implementation approaches
| Criterion | Monolith modification | Low-code sidecar module |
|---|---|---|
| Time-to-market (TTM) | High (regression) | Low (automation) |
| Risk to BSS core | High | Minimal (isolation) |
| Scalability | Limited | High |
| ODA compliance | Difficult to achieve | Native (API-first) |
From strategy to implementation
Modernizing telecom architecture requires a balanced approach. Specialists at Intecracy Group provide architectural consulting services, including technology stack audits and inventory of legacy components. The company's expertise allows for the implementation of UnityBase as a foundation for building modular registries. The UnityBase platform allows the use of Domain metadata for data description, automatic REST API generation, and the provision of RBAC/RLS, which integrate into the operator's ecosystem with minimal impact on business processes. For high-load projects or those with increased security requirements, Enterprise and Defence editions of the platform are available.
FAQ
How to integrate a low-code platform into BSS/OSS without replacing the core?
Use the sidecar pattern: move new functionality into a separate service on the UnityBase platform, which interacts with the core via standardized Open API without compromising the integrity of the monolith database.
What are the benefits of the sidecar pattern for telecom registries?
It enables independent scaling of services (e.g., IoT registries) and reduces the risk of regression errors, as the billing system core remains isolated from changes in the logic of new modules.
How to ensure new modules comply with TM Forum ODA standards?
Using Domain metadata mechanisms allows for the automatic generation of APIs that meet Open API specifications, ensuring the modularity required for integration into the ODA ecosystem.