RAN and Control Plane Sharing Between Private and Public 5G Networks
RAN and Control Plane Sharing in Private and Public 5G Networks
With 5G on the rise, more companies are setting up private networks to get top-notch performance, low latency, and secure connectivity for their essential applications. At the same time, public networks are growing to offer widespread coverage and mobility. A key factor that makes this coexistence work is RAN (Radio Access Network) and control plane sharing between public and private 5G networks.
This mixed model gives both operators and businesses a chance to make better use of resources, cut costs, and ensure steady service delivery by smartly sharing important network components. In this piece, we’ll take a deep dive into this concept, taking a look at the architecture as well as the pros and cons of RAN and control plane sharing.
Understanding the Basics: Public vs. Private 5G Networks
Before we get into how sharing works, let’s clarify what public and private 5G networks are all about:
Public 5G Network: Managed by mobile network operators (MNOs), these provide broad-area coverage for consumers and businesses.
Example use cases: mobile broadband, nationwide IoT connectivity.
Private 5G Network: Set up and managed by individual companies for specific use cases that need better security, ultra-low latency, or guaranteed bandwidth.
Example use cases: smart factories, autonomous vehicles, remote healthcare.
Public networks are great for coverage and scalability, while private networks excel in control and customization. By sharing RAN and control plane functions, both types can really enhance each other’s efforts.
What is RAN and Control Plane Sharing?
Radio Access Network (RAN) Sharing
RAN sharing lets private and public networks utilize the same physical 5G base stations (gNBs) to connect with user devices. Instead of setting up duplicate infrastructure, operators and businesses can reuse antennas, spectrum resources, and radio units.
Control Plane Sharing
In 5G architecture, the control plane is responsible for signaling, authentication, mobility, and session setup. By sharing the control plane, private networks can tap into the robust capabilities of public networks (like subscriber databases and mobility management).
User Plane Separation
While sharing control functions is feasible, the user plane usually remains distinct. The user plane is in charge of actual data traffic, and businesses often prefer to keep it within their secure domain to guarantee data security and sovereignty.
Architecture of RAN and Control Plane Sharing
The diagram provided illustrates this hybrid model well. Here’s a breakdown:
Public Network Components
Subscriber Database (DB): Stores user data for authentication and authorization.
5G Core Control Plane (5GC-CP): Manages signaling, registration, and session handling.
5G Core User Plane (5GC-UP): Routes data traffic to services and applications.
Private Network Components
Dedicated 5G Core User Plane (5GC-UP): Keeps enterprise data local.
Services within enterprise boundaries: Support critical applications like robotics, IoT, drones, and AR/VR.
Shared Components
5G gNB (Base Station): Shares radio access to support both private and public connectivity.
Control Plane Functions: Enable devices in private networks to authenticate and communicate using the public network’s control plane.
Flow Example:
A device in the private factory connects to the shared 5G gNB.
The control plane is managed through the public operator’s 5GC-CP, ensuring authentication and mobility management.
The user plane traffic (like sensitive data and industrial IoT flows) is processed within the private network’s local user plane for security.
Public users are connected through the same gNB, but their user plane traffic is directed to the operator’s public core.
Key Benefits of RAN and Control Plane Sharing
- Cost Efficiency
Companies can save by not having to build an entire standalone 5G core.
Shared gNB cuts down on infrastructure duplication.
Public operators can better utilize their spectrum and equipment.
- Faster Deployment
Companies can roll out private services quickly without waiting for a complete standalone setup.
Operators can broaden enterprise services with minimal new investments.
- Seamless Mobility
Devices can roam easily between private and public coverage.
Centralized control plane ensures a smooth user experience.
- Enhanced Security
Private domain keeps sensitive user traffic secure (local user plane).
Enterprises benefit from the public network’s strong authentication and subscriber management.
- Scalability and Flexibility
Enterprises can scale private services based on demand while benefiting from shared infrastructure.
Public operators can monetize enterprise use cases.
Potential Challenges
Despite the perks, RAN and control plane sharing can also pose challenges:
Integration Complexity: It’s not easy to synchronize policies and QoS (Quality of Service) across networks.
Data Privacy Issues: Companies need to ensure they are compliant while using shared control functions.
Operational Agreements: Clear SLAs (Service Level Agreements) between operators and enterprises are necessary.
Security Boundaries: Extra steps are needed to keep private user traffic safe from public networks.
Use Cases of RAN and Control Plane Sharing
Check out some industries and applications that are reaping the benefits of this model:
Manufacturing (Smart Factories)
Robotics, machine automation, and predictive maintenance.
Healthcare
Private hospital 5G for medical imaging, with public backup for roaming doctors.
Transportation & Logistics
Smart ports and airports with secure local operations and global connectivity.
Energy & Utilities
Private smart grid control with secure data while maintaining public access.
Public Safety
Emergency services that operate with private reliability and public coverage support.
RAN and Control Plane Sharing vs. Standalone Private 5G
Feature Standalone Private 5GShared RAN & Control Plane Model Deployment Cost High Moderate / Lower Security Full enterprise control Shared CP, private UP for security Mobility Support Limited to private coverage Seamless roaming via public CP Deployment Speed Slower, requires full setup Faster, leverages public infrastructure Scalability Enterprise-driven only Joint enterprise-operator scalability
Future Outlook
As 5G continues to evolve towards 6G and beyond, network slicing and advanced orchestration will likely enhance sharing models even further. Control plane sharing is expected to become a common approach for businesses needing secure, low-latency connectivity without going for a full standalone network.
Operators, in turn, will find new revenue opportunities by offering “5G-as-a-service” to enterprises via shared infrastructure.
Conclusion
RAN and control plane sharing between public and private networks fills the gap between specific enterprise needs and operator-led national coverage. It brings together the best of both worlds: cost savings, flexibility, security, and scalability.
For telecom professionals and businesses alike, this model provides a practical way to speed up digital transformation while keeping critical data under control.
As industries increasingly adopt 5G for mission-critical tasks, shared RAN and control plane models will be vital in fostering collaboration between public operators and private ventures.