A Case for Enabling Delegation of 5G Core Decisions to the RAN

Under conventional 5G system design, the authentication and continuous monitoring of user equipment (UE) demands a reliable backhaul connection between the radio access network (RAN) and the core network functions (AMF, AUSF, UDM, etc…). This is not a given, especially in disaster response and military operations. We argue that, in such 5 G deployments, decisions made by core functions can be effectively delegated to the RAN by leveraging the RAN’s computing resources and the micro-service programmability of the ORAN system architecture. To make a case, this paper explores a conceptual design that uses xApps to replicate core decision logic and maintain a core decision cache to further reduce response time. We detail the network security and performance implications of the proposed design and assess the feasibility by examining how it can be implemented within an open-source ORAN codebase.