PP5GS: A Per-Procedure and Stateless Core Network Architecture for 5G and Beyond

In its 5th Generation (5G), the introduction of the Service-Based Architecture (SBA) for the Mobile Core Network (5GC) has drastically changed the way these networks are designed and operated. Aiming toward higher flexibility and agility, the highly distributed SBA is the first step toward cloud-native deployments of 5GC. However, the high degree of functional decomposition has implications in terms of increased inter-NF communication overhead during the execution of control plane procedures, as well as increased complexity in orchestrating a highly inter-NF dependent system. In this work, we propose using a procedure-based functional decomposition for the 5GC NFs resulting in a Per-Procedure Stateless 5G (PP5GS) architecture. We implement Per-Procedure Network Functions (PPNFs) for a range of control plane procedures and perform intensive evaluations in a private cloud environment orchestrated with Kubernetes. The results show that PP5GS requires up to 34% and 55% fewer resources compared to stateful and stateless systems, respectively, while producing at least 40% less communication overhead. Moreover, it is able to complete control plane procedures up to 50% faster and is a better architecture for edge-offloading of 5GC NFs scenarios.