Implementation of a Service Based Interface for User Plane Functions in Beyond 5G and 6G Networks

Traditionally the Packet Forwarding Control Protocol has been used for the control of User Plane Functions within 5G Core Network. As we move toward beyond 5G and 6G networks, this approach presents several limitations in terms of scalability, flexibility, and non-alignment with 5G Service Based Architecture principles. To overcome these limitations, this paper proposes Service Based Interface as an alternative to PFCP for the control of UPFs in Beyond 5G and 6G networks. The design of the new SBI-based control interface aligns with 5G SBA principles by utilizing the RESTful design principles to expose the UPF functionalities. For better integration within 5GC, the SBI makes use of the Network Repository Function to facilitate service registration, discovery, and management of UPF functionalities. The feasibility of the proposed SBI is demonstrated through its implementation on the Fraunhofer FOKUS Open5GCore. By implementing SBI for the control of UPFs, the 5GC can benefit from enhanced scalability and better integration of UPF functionalities with other Network Functions. The work presented establishes that transitioning to an SBI for UPF control is a critical step in advancing 5GC capabilities.