Control and User Plane Separation for Next Generation EPC

Control and User Plane Separation (CUPS) is a concept introduced in the context of Evolved Packet Core (EPC), which is the core network architecture for LTE (Long-Term Evolution) and beyond. The primary goal of CUPS is to enhance the flexibility and scalability of the core network by decoupling the control plane functions from the user plane functions. This separation allows for more efficient resource utilization, better scalability, and easier deployment of new services.

Here's a technical explanation of Control and User Plane Separation for Next Generation EPC:

1. EPC Overview:
   • The Evolved Packet Core is the central component of the LTE network architecture, responsible for managing the signaling, mobility, and connectivity of user devices.
2. Control Plane and User Plane:
   • The EPC traditionally consists of both control plane and user plane functions.
   • Control Plane: Responsible for signaling, mobility management, and session establishment. It handles tasks like authentication, authorization, and policy enforcement.
   • User Plane: Deals with the actual user data traffic, such as IP packets. It is responsible for forwarding data between the user device and the external networks.
3. Motivation for CUPS:
   • As mobile networks evolve, the demand for more flexible and scalable architectures increases.
   • Separating the control and user planes allows for independent scaling, optimization, and deployment of these planes.
4. Control and User Plane Separation (CUPS):
   • In CUPS, the control plane and user plane functions are logically separated into distinct entities.
   • Control Plane Function (CPF): This entity handles all the control plane tasks. It includes functions like session management, policy enforcement, and mobility management.
   • User Plane Function (UPF): This entity is responsible for handling the user data traffic. It focuses on efficient packet forwarding and routing.
5. Key Components of CUPS:
   • User Plane Function (UPF):
     • Packet Forwarding: The UPF forwards user data packets between the user device and external networks.
     • QoS (Quality of Service): Ensures that the user data traffic meets the specified quality requirements.
   • Control Plane Function (CPF):
     • Session Management: Handles the establishment, modification, and termination of user sessions.
     • Policy Enforcement: Enforces policies related to user data traffic, ensuring compliance with network rules.
     • Mobility Management: Manages the mobility of user devices within the network.
6. Benefits of CUPS:
   • Scalability: Each plane can be scaled independently based on the network's requirements.
   • Flexibility: Easier introduction of new services and functionalities without impacting the entire core network.
   • Resource Optimization: Efficient resource utilization, as the control plane doesn't need to handle the actual user data traffic.
7. Deployment Considerations:
   • CUPS can be deployed gradually, allowing for a smooth transition from traditional EPC architectures.
   • It is important to ensure proper communication and coordination between the CPF and UPF for seamless operation.

Control and User Plane Separation is a concept that enhances the flexibility and scalability of the Evolved Packet Core by decoupling the control and user plane functions. This separation allows for more efficient resource utilization, better scalability, and easier deployment of new services in next-generation mobile networks.