5G Core Networks

- Overview

The 5G Core (5GC) is the brain of a Standalone 5G network, a cloud-native, software-defined architecture that enables new capabilities like faster speeds, ultra-low latency, network slicing, and edge computing, moving beyond 4G's hardware-based system to support diverse applications from smart cities to autonomous vehicles, unlocking 5G's full potential for enhanced mobile broadband (eMBB), reliable low-latency (URLLC), and massive IoT (mMTC). 

5GC moves beyond just faster phone data to become a flexible platform for innovation, allowing operators to create new services and tap into new industries (Industry 4.0, smart cities, etc.). It's the foundation for future growth, paving the way for 5G-Advanced and eventual 6G.

Key Aspects of 5G Core (5GC): 

1. Cloud-Native Architecture: Unlike 4G's rigid structure, 5GC uses virtualized, containerized microservices (Service-Based Architecture or SBA), making it flexible, scalable, and efficient to deploy new functions. 

2. Enables 5G Standalone (SA): It provides the necessary core for true 5G, working with 5G radio (NR) without relying on the 4G core, unlike initial Non-Standalone (NSA) deployments. 

3. Key Functions: Manages authentication, session management, policy enforcement, and data traffic. 

4. Core Capabilities (The "5G Triangle"):

• eMBB (Enhanced Mobile Broadband): Faster speeds for streaming, gaming, AR/VR.
• URLLC (Ultra-Reliable Low-Latency Communications): Near real-time responsiveness for critical applications like remote surgery or autonomous vehicles.
• mMTC (Massive Machine Type Communications): Connecting vast numbers of IoT devices, like smart meters. 

5. Network Slicing: Creates multiple virtual networks on one physical infrastructure, tailored for specific services (e.g., a slice for fleet management, another for smart meters). 

6. Edge Computing Integration: Supports placing compute closer to users for even lower latency.

- 5G Core Network Architecture

A 5G core network is the central brain of a 5G network, managing and directing all traffic with enhanced flexibility, scalability, and security. 

It uses a service-based architecture (SBA) where modular network functions interact through standard APIs, allowing it to run in cloud environments and support advanced features like network slicing and edge computing. 

This enables higher speeds, lower latency, and the ability to create customized virtual networks for different applications.  

1. Key features:

• Service-Based Architecture (SBA): A modular, cloud-native design where network functions (NFs) are individual services that communicate with each other via standard APIs, promoting flexibility and efficiency.
• Network Slicing: Creates multiple, virtual networks on a single physical infrastructure. Each slice can be customized to meet the specific requirements of different applications, such as high bandwidth for video streaming or ultra-low latency for autonomous vehicles.
• Edge Computing: Integrates with edge computing, allowing data to be processed closer to the user or device. This significantly reduces latency and improves the efficiency of data-intensive applications.
• Enhanced Security: Provides advanced security features, including more robust encryption, which is crucial for protecting sensitive data, especially in private networks.
• Flexibility and Scalability: The modular and cloud-native nature allows the network to be easily scaled and adapted to accommodate growing demands and new technologies.

2. How it works: 

• Registration and Discovery: Network Functions (NFs) register their services with a Network Repository Function (NRF), allowing other NFs to discover and communicate with them.
• User Mobility and Access: The Access and Mobility Management Function (AMF) handles user registration, authentication, and tracking mobility.
• Session Management: The Session Management Function (SMF) manages user sessions, including controlling data flow and quality of service (QoS).
• Data Forwarding: The User Plane Function (UPF) is responsible for the actual forwarding of user data packets between the device and the network.
• Network Slice Selection: The Network Slice Selection Function (NSSF) selects the appropriate network slice for a user's session based on their application needs.

- 5G Core Migration and Beyond

5G Core (5GC) migration involves shifting from older architectures to a flexible, cloud-native Service-Based Architecture (SBA) using IT principles, enabling features like network slicing and faster service deployment, with pathways like Non-Standalone (NSA) to Standalone (SA) for full 5G benefits. 

Beyond 5G, the focus moves towards 6G, emphasizing ultra-low power, AI integration, enhanced reliability, and seamless device cooperation, reusing 5G infrastructure where possible for a cost-effective transition, potentially featuring a fully standalone 6G core for maximum innovation. 

1. 5G Core Migration: Key Aspects: 

• Architectural Shift: Moving from monolithic 4G EPC to 5GC's SBA, using IT-based protocols (HTTP/2, TCP) for agility and cloud-native functions.
• Deployment Strategies: Operators use options like NSA (using 4G core) then migrating to SA (full 5G core) or direct SA, often with hybrid infrastructure.
• Enabling Advanced Features: 5GC is essential for full 5G capabilities like end-to-end network slicing, crucial for new B2B/B2C services.
• Security & Virtualization: Requires security upgrades for increased traffic and supports a transition to virtualized, hybrid networks.

2. Beyond 5G (Towards 6G):

• Focus Areas: Ultra-low power, high reliability, autonomy, and seamless integration with other systems (e.g., satellites).
• Infrastructure Reuse: Strategies aim to reuse 5G hardware (like Radio Units) and software (cloud platforms) to cut 6G deployment costs.
• Migration Pathways: Dual-Stack and MRSS (Multi-Radio Spectrum Sharing) are considered to support 5G/6G coexistence.
• Maximized Potential: A standalone 6G RAN and core is seen as key to fully leverage AI, cloud, and new revenue opportunities, limiting legacy interworking.

3. The Road Ahead:

• Cloud-Native & AI: The trend towards virtualized, programmable networks continues, with AI playing a crucial role in management and new services.
• New Models: Growth in neutral hosting, managed services, and micro-operator models for specialized enterprise use cases.
• Key Use Cases: Industrial automation, telerobotics, and ambient intelligence will drive demand for advanced B5G/6G features.

- 5G Core Network Functions

The main network functions of a 5G Core (5GC) are to establish connectivity, manage mobility, handle authentication and authorization, and control subscriber data and policies. 

Unlike 4G, 5G Core is a cloud-native, software-based system that enables greater flexibility and agility. It is the heart of the 5G network, providing high speeds, low latency, and supporting advanced capabilities like network slicing, which allows for the creation of multiple virtual networks on a single physical infrastructure. 

1. Core 5G network functions: 

• Mobility management: Tracks and manages the movement of a user device through the network.
• Authentication and authorization: Verifies that the user is legitimate and has permission to access the network and its services.
• Subscriber data management: Stores and manages user-specific information, such as their subscription details.
• Policy management: Controls the rules and policies that govern how network services are delivered, including data packet routing.

2. Key characteristics of the 5G Core:

• Cloud-native architecture: The 5GC is built on a virtualized, cloud-native architecture, allowing for greater flexibility and scalability.
• Service-Based Architecture (SBA): The architecture decomposes network functions into modular services that can be independently updated or scaled.
• Network slicing: The ability to create multiple, isolated virtual networks on the same physical infrastructure to cater to different services, like enhanced mobile broadband or ultra-reliable low-latency communications.
• Automation: New automation capabilities are essential for managing the complexity of the 5G network.
• Edge computing: The network's design supports edge computing, enabling data processing closer to the end user to further reduce latency for applications like autonomous vehicles. 

- Core Components of 5G Networks

The core components of a 5G network include the User Equipment (UE), the Radio Access Network (RAN) which includes the gNodeB (gNB) base station and the Distributed Unit (DU), and the 5G Core Network (5GC). 

The 5GC itself has functions like the Access and Mobility Management Function (AMF), and external infrastructure is also critical for services like security and load balancing. 

Core Components of 5G Networks: 

1. User Equipment (UE): The devices that users operate, such as smartphones, tablets, and other connected devices. 

2. gNodeB (gNB): The base station in the 5G Radio Access Network (RAN) that handles wireless communication for a specific area, also known as a cell. 

3. Distributed Unit (DU): A key part of the 5G RAN, which handles the real-time processing of radio functions. 

4. 5G Core Network (5GC): The central brain of the network, composed of cloud-native and service-based components that provide core functions and services.

• Access and Mobility Management Function (AMF): A specific function within the 5GC that manages a device's connection to the network and its location.
• Other core functions: Include the Session Management Function (SMF), User Plane Function (UPF), and Unified Data Management (UDM).

5. External Network Infrastructure: The underlying hardware and software that supports the 5G core, providing capabilities like load balancing, security, and the data center fabric.

- Why You Need A 5G Core 

You need a 5G Core (5GC) to unlock the full potential of 5G because it is the central component that enables advanced features like ultra-low latency, high throughput, and massive device connectivity, which are crucial for applications like industrial IoT, autonomous vehicles, and remote surgery. 

While Non-Standalone (NSA) 5G can use existing 4G networks, a 5G Core is necessary for Standalone (SA) 5G to deliver the performance, reliability, and flexibility required for next-generation services and to simplify network operations. 

Key reasons to need a 5G Core: 

• Enables 5G's full potential: The 5G Core is the fundamental part of a 5G network that is required to achieve ultra-low latency, high throughput, and massive connection density that the 5G New Radio (NR) alone cannot deliver.
• Supports advanced applications: It provides the capabilities for mission-critical applications such as industrial automation, remote surgery, smart grids, and self-driving vehicles, which require ultra-reliable low-latency communications (URLLC).
• Enhances user experience: The 5G Core improves end-user experience by enabling faster connectivity speeds, better reliability, and more personalized services.
• Simplifies operations and service creation: It uses a cloud-native, microservices-based architecture that allows for automation, dynamic scaling, and easier service creation, which simplifies network operations and increases agility.
• Provides greater network flexibility: The 5G Core enables end-to-end network slicing, which allows communication service providers to dedicate network resources to specific use cases or services with different service level agreements (SLAs).