An AI-Driven Closed-Loop Assurance Framework for the Cloud-Native 5G Core Network: Autonomous Anomaly Detection and Self-Healing of Multi-Vendor Network Functions

The migration of the mobile core to a cloud-native, service-based 5G Standalone (SA) architecture replaces a small number of monolithic nodes with dozens of dynamically scaled, containerised network functions (NFs) communicating over service-based interfaces. This elasticity is the source of 5G's agility, but it also defeats the manual, threshold-based operational practices that assured previous core generations: faults now propagate across NFs in seconds, and human-paced remediation cannot protect the service-level agreements (SLAs) of latency-critical slices. This paper proposes Autonomous Core Assurance and Remediation (ACAR), an AI-driven, closed-loop assurance framework that brings the zero-touch principle to the multi-vendor 5G core. ACAR is organised as an Observe–Analyse–Decide–Act control loop across three planes: an observability plane that collects NF KPIs, signalling rates, resource utilisation, and slice-SLA metrics over standardised interfaces; an AI analytics plane in which an autoencoder scores reconstruction error to detect anomalies on unlabelled telemetry and a classifier maps each fault to a remediation policy; and a remediation orchestration plane that executes policy-guarded self-healing actions — scale-out, restart, reroute, isolate — through NFV-MANO and the service mesh. The framework is aligned with the ETSI Zero-touch network and Service Management (ZSM) reference architecture and is designed for a sovereign, in-Kingdom 5G core. A numerical evaluation injects a signalling-storm anomaly against a multi-vendor SMF and shows that ACAR detects within a few seconds and reduces SLA-violation duration by roughly 80% and mean time to recovery by roughly two-thirds relative to a reactive baseline. All metrics are expressed against modelled baselines rather than proprietary operator data.