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5g nsa core

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In 5G NSA (Non-Standalone) deployments, the 5G core network, often referred to as 5GC (5G Core), works in conjunction with existing LTE infrastructure to provide enhanced services and capabilities. The 5G core network introduces new architectural elements and functionalities compared to the previous generations. Let's explore the technical details of the 5G NSA core network:

1. Architecture Overview:

1.1 Coexistence with LTE Core:

  • In 5G NSA, the 5GC coexists with the LTE Evolved Packet Core (EPC). The EPC continues to handle LTE connections, while the 5GC manages 5G NR connections, creating a dual connectivity scenario.

1.2 Functional Elements:

  • The 5G Core comprises various functional elements, each responsible for specific tasks related to control, user plane, mobility, session management, and connectivity.

2. Key Functional Elements:

2.1 AMF (Access and Mobility Management Function):

  • The AMF is responsible for access and mobility management in the 5G Core. It handles tasks such as registration, connection setup, mobility between cells, and connection release.

2.2 SMF (Session Management Function):

  • The SMF is in charge of session management in the 5G Core. It establishes and manages user sessions, including the establishment, modification, and release of bearers for user data transfer.

2.3 UPF (User Plane Function):

  • The UPF manages the user plane data transfer in the 5G Core. It is responsible for routing user data between the 5G NR gNB (gNodeB) and the core network, ensuring efficient data delivery.

2.4 UDM (Unified Data Management):

  • The UDM is responsible for unified data management in the 5G Core. It stores and manages subscriber-related data, including authentication information, subscriber profiles, and subscription information.

2.5 AUSF (Authentication Server Function):

  • The AUSF performs authentication functions in the 5G Core. It authenticates users and generates authentication vectors for secure access to the 5G network.

2.6 NSSF (Network Slice Selection Function):

  • The NSSF is involved in network slicing in the 5G Core. It assists in selecting and managing the appropriate network slices based on the service requirements and user context.

2.7 PCF (Policy Control Function):

  • The PCF is responsible for policy control in the 5G Core. It manages policies related to QoS (Quality of Service), traffic steering, and other parameters to optimize network performance.

2.8 NEF (Network Exposure Function):

  • The NEF enables external applications and services to access network information and services. It provides a secure and standardized interface for external entities to interact with the 5G network.

2.9 UDR (Unified Data Repository):

  • The UDR is a unified data repository in the 5G Core. It stores subscription and session-related data, providing a centralized location for accessing subscriber information.

2.10 N3IWF (Non-3GPP Interworking Function):

  • The N3IWF facilitates communication between 5G NR and non-3GPP technologies, such as Wi-Fi. It enables interworking and seamless handovers between 5G and non-3GPP access networks.

3. NG Interface:

3.1 NG Interface Overview:

  • The NG interface connects the 5G NR gNB to the 5G Core Network. It serves as the interface for communication between the gNB and various 5GC functions.

3.2 Signaling and User Plane Separation:

  • The NG interface supports the separation of signaling and user plane traffic. This separation allows for scalability and flexibility in the deployment of network functions.

3.3 Functional Split:

  • The NG interface is designed to support various functional splits between gNB and the 5GC functions, allowing for different deployment scenarios and optimizations.

4. Control Plane and User Plane Separation:

4.1 Control Plane Functions:

  • Control plane functions, such as AMF and SMF, handle signaling, session management, and mobility management. These functions are responsible for managing the establishment, modification, and release of connections.

4.2 User Plane Functions:

  • User plane functions, such as UPF, manage the actual data transfer between the gNB and the core network. These functions ensure efficient routing and delivery of user data.

4.3 Separation Benefits:

  • The separation of control plane and user plane functions allows for scalability, flexibility, and efficient resource utilization in the 5G Core.

5. Security Considerations:

5.1 Authentication and Authorization:

  • The 5G Core includes mechanisms for user authentication and authorization to ensure secure access to the network and services.

5.2 Encryption:

  • End-to-end encryption is employed to secure user data during transmission between the UE, gNB, and the core network.

5.3 Integrity Protection:

  • Measures are implemented to protect the integrity of signaling and user data, preventing unauthorized modifications during transit.

6. Network Slicing:

6.1 NSSF and Network Slices:

  • The NSSF plays a key role in network slicing, assisting in the selection and management of network slices based on service requirements. Network slicing allows the creation of virtualized networks tailored for specific use cases.

6.2 Service Differentiation:

  • Network slicing enables service providers to offer differentiated services with varying QoS, latency, and capacity characteristics to meet the diverse requirements of applications and industries.

7. Integration with LTE Core:

7.1 EPC and 5GC Interaction:

  • The 5GC and LTE EPC interact seamlessly in 5G NSA deployments, allowing for a smooth transition and coexistence of LTE and 5G NR technologies.

7.2 Dual Connectivity:

  • Dual connectivity is established between LTE eNBs and 5G NR gNBs, providing users with simultaneous access to both networks for enhanced performance.

In summary, the 5G NSA core network, in Option 3x, is a vital component that integrates with existing LTE infrastructure to provide enhanced services and capabilities. It introduces new functional elements, supports dual connectivity, and facilitates the coexistence of LTE and 5G NR technologies. The architecture is designed to be flexible, scalable, and capable of meeting the diverse requirements of 5G services and applications.