Architectural Design for Legacy Continuity for the 6G Core

The continuous evolution of 5G networks demands that CSPs and MNOs continuously modernize their operations and introduce new capabilities while preserving existing services. This work introduces a standardized approach that leverages the TM Forum Open Digital Architecture and its suite of Open APIs to enable smooth integration and evolution to next generation networks and interfaces. By introducing a transformation layer that maps modern API requests to the TMF service characteristics of existing services, the proposed framework supports integration and lifecycle management with minimal modifications to legacy services. Additionally, it facilitates the preservation and extension of existing charging and billing policies, to support monetization of new service offerings. The approach we proposed was validated through a prototype use case in which an already existing 5G UE QoS profile enforcement service was exposed via a developer-friendly CAMARA API. The results demonstrate negligible operational overhead and confirm our approach’s suitability for service continuity in scalable, real-world deployments.