5G Core Network Basic Architecture - Control Plane

Summary

This lesson delves into the architecture of the 5G control plane, explaining key components like the AMF, AUSF, UDM, SMF, and PCF. The AMF manages user access and mobility, authenticating UEs in coordination with the AUSF and UDM. The UDM provides essential subscription information stored in the UDR, while the SMF oversees the establishment and control of data sessions. Finally, the PCF generates and manages policies that guide network behavior. Together, these functions create a robust framework for managing connectivity and ensuring seamless communication within the 5G network.

Takeaways

• 😀 The Control Plane architecture in 5G includes key functions such as AMF, AUSF, UDM, SMF, and PCF.
• 🔑 The Access and Mobility Management Function (AMF) handles access authentication and mobility management for User Equipment (UE).
• 📍 AMF is the first point of connection in the control plane for the G node B and serves as a termination point for NAS messages.
• 🔒 The Authentication Server Function (AUSF) is responsible for authenticating UEs, working closely with the AMF.
• 📊 Unified Data Management (UDM) provides UE subscription information to other network functions and connects to the Unified Data Repository (UDR) for data storage.
• 📶 Session Management Function (SMF) manages data sessions, including establishing, modifying, and terminating PDU sessions between UE and UPF.
• ⚙️ The SMF provides necessary session management parameters to UPF, G node B, and UE for efficient session control.
• 📜 The Policy Control Function (PCF) generates and manages policies that control overall network behavior.
• 📥 PCF retrieves UE subscription policy information from UDR to ensure proper policy application across the network.
• 🔗 In summary, each component plays a crucial role in ensuring smooth operation and management of the 5G network infrastructure.

Q & A

What does AMF stand for and what is its primary function?

AMF stands for Access and Mobility Management Function. Its primary functions include access management, mobility management, and serving as a control plane termination point for the RAN and NAS messages.

How does the AMF handle access authentication and authorization?

The AMF authenticates UEs and authorizes them to access the 5G network in coordination with the AUSF and UDM.

What role does the AUSF play in the control plane architecture?

AUSF stands for Authentication Server Function, and its main role is to authenticate UEs during the access process, often connecting with the UDM during this procedure.

What is the function of the UDM in the control plane?

UDM stands for Unified Data Management, and it provides UE subscription information to other network functions when needed, but does not store this information itself.

What does UDR stand for and what is its purpose?

UDR stands for Unified Data Repository, and it acts as the database that stores the subscription information of all UEs in the network, which the UDM accesses to retrieve necessary data.

Can you explain the responsibilities of the SMF?

SMF stands for Session Management Function, which is responsible for establishing, modifying, and terminating PDU sessions between the UE and the UPF. It also provides necessary parameters for session management.

What is the role of the PCF in the control plane architecture?

PCF stands for Policy Control Function, and it provides a unified policy framework to control network behavior, generating and controlling all policies related to network functions.

How does the PCF interact with the UDR?

The PCF accesses the UDR to retrieve UE subscribed policy information, which it then uses to generate and deliver relevant policies to other network functions.

What is the significance of NAS messages in the context of AMF?

NAS messages, or Non-Access Stratum messages, are the messages sent between the UE and the AMF. They are important for establishing a logical link for communication without direct connections.

What does the AMF manage regarding UE mobility?

The AMF is responsible for managing the mobility of the UE, keeping track of its location and facilitating its movement between different locations within the network.