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

TL;DR

This paper explores delegating 5G core decision-making to the RAN to improve resilience in disaster and military scenarios, proposing specific designs and analyzing their trade-offs.

Contribution

It introduces novel designs for core-RAN decision delegation leveraging O-RAN architecture, addressing reliability issues in critical scenarios.

Findings

Delegation improves resilience in disaster scenarios

Designs reveal performance and security trade-offs

Micro-service approach enables flexible decision delegation

Abstract

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 propose that, in these scenarios, 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 O-RAN system architecture. This paper presents several concrete designs of core-RAN decision delegation, including caching of core decisions and replicating some of the core decision logic. Each design has revealed interesting performance and security trade-offs that warrant further investigation.