• 5G
• November 6, 2025

Bridging Private and Public 5G Networks: The Next Frontier in Seamless Connectivity

As 5G technology transforms global communications, more enterprises are adopting private 5G networks to enhance control, reliability, and security. These non-public networks (NPNs) are tailored for industrial automation, real-time analytics, and Internet of Things (IoT) applications in sectors such as manufacturing, utilities, healthcare, and defense. 

However, as devices move beyond these private networks, connectivity often falters. Maintaining service continuity across private and public 5G networks—without user intervention—has become a significant challenge for enterprises and network operators. 

Why 5G Interworking Matters 

Private 5G networks provide exceptional customization and performance, but they often function in isolation. To fully unlock the potential of 5G, enterprises must enable interworking—a secure and seamless connection between private and public networks. 

This integration offers four key advantages: 

1. Seamless Mobility: Devices like drones, autonomous vehicles, and handhelds require uninterrupted connectivity as they transition between networks. Interworking guarantees smooth handovers and consistent quality of service. 
2. Off-Premises Access to Private Services: Employees or sensors located outside the private network need secure access to enterprise systems. 
3. Optimized Resource Usage: Public networks can supplement private ones during periods of high demand, improving scalability and cost efficiency. 
4. Support for Critical Services: Functions such as voice, SMS, and emergency access depend on public 5G availability, both on and off enterprise premises. 

Challenges in Achieving Seamless Interworking 

Despite the clear benefits, achieving effective interworking involves complex technical and operational challenges: 

• Spectrum Alignment: Private 5G often operates on shared spectrum, while public networks rely on licensed bands, complicating unified access. 
• Network Slicing Management: Ensuring consistent policies across different domains requires meticulous coordination. 
• Security and Isolation: Enterprises must selectively expose connectivity while safeguarding their data and operations. 
• Scalability versus Cost: Balancing flexibility with economic feasibility is crucial for large-scale deployment. 

Blueprint Approaches for Interworking 

Several architectural models have emerged, each tailored to address specific needs: 

• Standalone Private–Public Interworking (Single SIM): A standards-based design allowing one SIM to access both networks, ensuring scalability and high security—ideal for environments such as defense and smart grids. 
• Hybrid Coexistence with Network Slicing (Single SIM): This model combines standalone and integrated setups through slicing and Closed Access Groups (CAGs) for seamless mobility, suited for industries like healthcare, AR/VR, and drone operations that require concurrent voice and data. 
• Multi-Operator Core Network (Dual SIM): This model uses shared radio access between public and private cores, with each mapped to a SIM. One core handles private data, while the other manages public voice, making it effective for railway diagnostics and transport systems that need off-premises access. 
• Roaming-Based Integration: This setup emulates roaming to enable secure access to private services over public 5G. Although it is highly secure, it requires significant integration effort—making it best for sectors such as finance, defense, and critical infrastructure that need strict data sovereignty. 

Each architecture balances mobility, security, and cost differently, offering flexibility tailored to the enterprise’s priorities. 

Validating Interworking and Mobility with Simnovus 

Designing interworking architectures is just half of the journey; the other half involves ensuring they function seamlessly in real-world scenarios. The Simnovus UE Simulator plays a crucial role in this validation process, allowing operators and enterprises to emulate thousands of user devices simultaneously to test: 

• End-to-end interworking between private and public 5G networks. 
• Mobility transitions as user equipment (UE) moves across coverage zones. 
• Quality of Service (QoS) assurance and latency under realistic traffic conditions. 

By simulating diverse user behavior, the UE Simulator validates how effectively connections persist during handovers and how securely authentication, slicing, and policy functions operate during transitions. 

In addition, the Simnovus Network Emulator enables precise testing of dual-SIM use cases, emulating both public and private network cores. This setup simulates how a device manages concurrent connectivity—data via private 5G and voice via public 5G—helping verify performance under load, evaluate network-selection logic, and minimize service disruption during network switching. 

Together, these tools facilitate comprehensive pre-deployment validation, ensuring that networks are interoperable, resilient, and compliant with 3GPP standards before going live. 

The Road Ahead 

The convergence of private and public 5G networks represents a pivotal advancement in enterprise connectivity. While the vendor ecosystem continues to evolve, the trend is clear: future-ready networks will require secure, scalable, and verifiable interworking solutions. 

At Simnovus, we empower telecom innovators to confidently test these architectures, paving the way for a more connected future.