5g core service based architecture

The 5G Core (5GC) Service-Based Architecture (SBA) is a fundamental aspect of 5G networks that brings flexibility, scalability, and efficiency to the deployment and operation of 5G services. The SBA is designed to be more modular and service-oriented compared to previous generations of mobile network architectures.

Below is a technical explanation of the key components and concepts in the 5G Core SBA:

1. Service-Based Architecture (SBA):
   • Definition: SBA is a paradigm shift from the traditional monolithic architectures to a more flexible and modular structure based on services.
   • Key Features:
     • Decomposes network functions into modular services.
     • Supports horizontal scaling and service reuse.
2. Network Functions and Services:
   • Network Functions (NFs):
     • Defined as individual software entities that provide specific network-related functions.
     • Examples include AMF (Access and Mobility Management Function), SMF (Session Management Function), and UPF (User Plane Function).
   • Services:
     • Services are the functionalities exposed by NFs in a service-oriented architecture.
     • Services can interact with each other using well-defined service-based interfaces.
3. Service-Based Interfaces (SBIs):
   • Definition: SBIs enable communication and interaction between different NFs and services within the 5G Core network.
   • Key Features:
     • Based on RESTful principles, using HTTP/2 as the transport protocol.
     • Define standardized operations for various network functions.
4. Network Repository Function (NRF):
   • Definition: NRF is a key component in the SBA responsible for maintaining a registry of available NFs and their service-based interfaces.
   • Key Functions:
     • Service discovery: Helps NFs discover the existence and capabilities of other NFs.
     • Load balancing: Aids in distributing the load among multiple instances of the same NF.
5. Unified Data Management (UDM) and Authentication Server Function (AUSF):
   • UDM: Manages user-related information and subscriptions.
   • AUSF: Handles authentication and key management for the access network.
6. Session Management Function (SMF) and Access and Mobility Management Function (AMF):
   • SMF: Manages session-related information, including session establishment, modification, and termination.
   • AMF: Manages access and mobility aspects, including registration, handovers, and mobility-related policies.
7. User Plane Function (UPF):
   • Definition: Handles the user data plane, including the forwarding of user data packets.
   • Key Features:
     • Supports user plane functions with different characteristics, enabling diverse use cases.
8. Control Plane/User Plane Separation (CUPS):
   • Definition: CUPS decouples the control plane and user plane functionalities, allowing independent scaling and deployment.
   • Key Benefits:
     • Enables efficient resource utilization and dynamic scaling based on traffic patterns.
9. Network Slicing:
   • Definition: Network slicing allows the creation of isolated and logically independent network instances, each customized for specific services or verticals.
   • Key Components:
     • Network Slice Instance (NSI): Represents an instance of a network slice.
     • Slice-Specific NFs: NFs dedicated to a particular slice.
10. Interworking with Previous Generations:
    • 5G Core is designed to interwork with existing 4G (LTE) and earlier generation networks, facilitating a smooth transition.