6G RAN-Core Control Plane Convergence Essential Functionality Study

With the centralization of the RAN control functionality, a very large number of near real-time network optimization use cases have appeared. Until now, each of them has been implemented and validated as isolated network management functions, named xApps in Open RAN terminology. To be able to progress toward realistic, commercially deployable functionality, a convergence of this functionality is needed, because their complete isolation would result in duplicated interface usage and conflicting decisions. In this article we present a study on how a major number of these use cases can be implemented convergently, underlining the required functionality from the central RAN units, the grouping, and interaction of the network management decision. Furthermore, we present an implementation roadmap for the development of such functionality as part of the Fraunhofer FOKUS Open5GCore toolkit, as a reference for how such functionality can be prototyped, validated, and integrated with external algorithms easily, as to benefit from the large academic research.