5G Core Service-Based Architecture

- Overview

The 5G Core Service-Based Architecture (SBA) is a cloud-native, modular design using independent Network Functions (NFs) communicating via APIs (HTTP/2, RESTful) over Service-Based Interfaces (SBIs), enabling flexibility, scalability, and microservices deployment for new 5G services, contrasting with 4G's fixed interfaces. 

It allows NFs to act as service producers or consumers, using a central registry (NRF) for service discovery, supporting advanced features like network slicing and edge deployment for low-latency applications, and decoupling control and user planes (CUPS) for efficient resource use. 

1. Key Principles of 5G SBA: 

• Service-Based Interfaces (SBIs): NFs expose functionalities as services, communicating through standardized APIs over HTTP/2, rather than fixed interfaces.
• Network Functions (NFs): Control plane functions are decomposed into independent, reusable, self-contained NFs (e.g., AMF, SMF, PCF, UDM).
• Cloud-Native & Microservices: NFs are deployed as stateless microservices, often containerized, allowing for agility, scalability, and efficient resource use.
• Service Discovery: The Network Repository Function (NRF) allows NFs to register their services and discover other NFs, enabling dynamic interactions.
• Control & User Plane Separation (CUPS): Decouples the control plane (control functions) from the user plane (data path), allowing User Plane Functions (UPFs) to be deployed closer to the edge for lower latency.

2. Benefits of SBA: 

• Flexibility & Agility: Rapid deployment, scaling, and updates of network functions.
• Innovation: Supports new services for industries like IoT, healthcare, and public safety.
• Efficiency: Optimized resource utilization through microservices and CUPS.
• Automation: Enables end-to-end network automation for dynamic service delivery.

3. 5G Standalone (5G SA): 

• A 5G SA network uses the full 5G Core (5GC) with SBA, relying on 5G Standalone New Radio (NR) for enhanced capabilities, unlike Non-Standalone (NSA) networks that still use the 4G core.