Sign in Subscribe

5g core network functions

Last updated on 


The 5G Core (5GC) network is designed to support a multitude of services with high reliability, scalability, and performance, especially in terms of low latency and high data rates. To achieve this, the 5GC is built on a service-based architecture (SBA) that offers a more flexible, modular, and scalable structure compared to previous generations.

Here are some of the key 5G Core network functions and a technical explanation of each:

  1. Access and Mobility Management Function (AMF):
    • Functionality: AMF manages the registration and mobility of users (UEs) within the 5G network. It handles initial registration, authentication, mobility procedures, and session management.
    • Technical Details: When a user equipment (UE) connects to the 5G network, the AMF initiates procedures such as authentication and context establishment. It tracks the UE's location and manages handovers between different access types (e.g., 5G to Wi-Fi).
  2. Session Management Function (SMF):
    • Functionality: SMF is responsible for setting up, modifying, and releasing data sessions between the UE and the data network. It manages data plane connectivity.
    • Technical Details: SMF handles the data flows for user sessions, including IP address allocation, quality of service (QoS) enforcement, and packet routing. It establishes and maintains data paths for user traffic based on policies and network conditions.
  3. User Plane Function (UPF):
    • Functionality: UPF is responsible for packet routing, forwarding, and other data plane functions. It ensures efficient data transport between the UE and external networks.
    • Technical Details: UPF performs packet switching, traffic routing, and applies QoS policies for user data traffic. It may have multiple instances for scalability and location optimization. UPF ensures low latency and high throughput for diverse service requirements.
  4. Network Repository Function (NRF):
    • Functionality: NRF maintains a service registry and discovery function. It helps in locating available services and functions within the 5G Core network.
    • Technical Details: NRF provides a centralized mechanism for service discovery in the SBA architecture. When a function needs to communicate with another function, NRF facilitates the discovery process by mapping service names to network function addresses.
  5. Policy Control Function (PCF):
    • Functionality: PCF manages policy decisions and enforcement related to QoS, charging, and access control. It ensures that network resources are utilized efficiently and according to specified policies.
    • Technical Details: PCF defines policies based on operator requirements and network conditions. It interacts with other functions to enforce policies related to bandwidth allocation, traffic prioritization, and service differentiation. PCF ensures that user sessions adhere to predefined rules and regulations.
  6. Unified Data Management (UDM):
    • Functionality: UDM manages user-related data such as subscription information, authentication credentials, and policy profiles. It provides a centralized repository for user data management.
    • Technical Details: UDM stores user profiles, subscription data, and authentication credentials. It interfaces with other functions to provide user context and information necessary for network operations. UDM ensures secure and efficient access to user-related data across the 5G network.