5G SA roaming: models, use cases, and what’s next

According to Kaleido Intelligence’s 5G SA tracker (2024), there are now 63 commercial 5G networks live worldwide, signaling the rapid adoption of 5G Standalone (SA) technology. As these networks expand, roaming is evolving beyond simple connectivity to enable transformative use cases like mobile private networks, IoT, and critical communications. However, this evolution brings complexity. Operators must adopt roaming architectures that balance flexibility, scalability, and security while meeting the demands of high-performance, low-latency applications. 

In this blog, we’ll take a closer look at the current roaming models, explore key use cases enabled by 5G SA roaming, and consider where the industry is heading next. 

To understand the foundation of 5G SA roaming, let’s revisit the GSMA’s NG.113 roaming guidelines. These outline five models for roaming setups, offering operators flexibility based on their priorities and resources. Here’s a quick refresher: 

• Direct Bilateral Agreements (Model 1): Two operators directly connect their SEPPs, secured with mutual trust and encryption. Simple, straightforward, and works well for trusted partnerships.
  • Drawback: Operators must manage all roaming services in-house, which adds operational complexity and limits scalability. 
• Outsourced SEPPs (Model 2): Operators can outsource SEPP management to a service provider, keeping things manageable. This approach comes in three variants: 
  • Model 2.1: Service provider operates within the operator’s domain. 
  • Model 2.2: Entire setup is hosted externally. 
  • Model 2.3: Large operator groups centralize SEPPs, allowing affiliates to share one system.
  • Drawback: Model 2.1 shares scalability issues with Model 1, as it lacks resource sharing and relies on heavy customisation. Model 2.2 means relying on third parties for critical roaming infrastructure and reduced control. Group SEPPs (Model 2.3) reduce TLS overhead by sharing a secure domain, often using a combined PLMN ID list, but deployment is akin to Model 2.2. 

• Service Hub (Model 3): Service hubs aggregate signaling for multiple operators, reducing the need for one-on-one agreements. It’s the easiest way to set up connections, minimizing TLS connections and security overhead. TLS hop-by-hop is preferred over PRINS for its smooth outsourcing capabilities and lower complexity. 
• Roaming Hub (Model 4): Similar to Model 3 on a technical interface level but handles all roaming-related services such as contracts, billing, and testing. While other models focus on bilateral agreements, Roaming Hubs specialize in hub-based agreements. 

With these models in mind, let’s explore how they align with the transformative use cases made possible by 5G SA roaming. 

5G SA roaming isn’t just about keeping travellers connected abroad—it’s about enabling the next wave of technology and innovation. The right roaming models ensure these use cases can thrive while maintaining high performance and security. 

MPNs are standalone 5G environments designed for enterprises, enabling them to run customized, secure networks for various industries like manufacturing automation, remote healthcare, or logistics. 

• Why roaming matters: Enterprises often operate across multiple geographies. Roaming ensures their devices can seamlessly connect to public 5G or 4G networks or partner MPNs outside their home regions. Use cases include supply chain tracking, where IoT devices roam internationally while staying securely connected to the enterprise’s private network. 

• Best model: MPNs need low latency and secure connectivity, especially for sensitive data like real-time factory telemetry or patient diagnostics. Regional breakout is critical to avoid cross-continental home routing. Service Hubs (Model 3) provide efficient, shared resources for regional breakout.  

From connected cars to healthcare wearables, IoT devices require uninterrupted connectivity to deliver value. For global use cases, roaming is essential to ensure they remain functional across borders. 

• Why roaming matters: IoT devices often have long lifespans and operate in remote locations, making seamless roaming a necessity. Applications like autonomous vehicle navigation rely on real-time updates from the cloud, demanding ultra-low latency even when moving across networks. 

• Best model: IoT roaming needs scalability to manage billions of devices while minimizing operational complexity. Service Hubs enable IoT device manufacturers to onboard once and roam globally without managing individual agreements. TLS hop-by-hop ensures secure communication without the complexity of end-to-end customization required by PRINS. 

5G’s reliability and low latency make it ideal for critical communications, from public safety networks to disaster recovery. Roaming is essential for ensuring these services remain operational across borders or regions. 

• Why roaming matters: Emergency services need reliable access to their home network resources when working internationally, such as during natural disasters or multinational operations. Applications like real-time drone surveillance during disaster response depend on uninterrupted connectivity and high-speed data transfer. 

• Best model:  Critical communications require priority handling and network slicing, which current roaming architectures are only beginning to address. Regional breakout remains essential to avoid cross-continental routing delays. Model 3, Service Hub, is best suited to achieve this, offering an efficient, shared resource setup that supports regional breakout.
  

Global businesses are increasingly leveraging 5G for smart offices, remote collaboration, and mobile-first workflows. 

• Why roaming matters: Teams traveling across regions need uninterrupted, high-performance connectivity for video conferencing, file sharing, and access to enterprise applications. Roaming ensures consistent experiences and supports services like zero-trust network access (ZTNA) to keep enterprise data secure. 

• Best model: Hosted SEPPs (Model 2.2) and Service Hubs (Model 3) provide scalability and seamless roaming. Enterprises would most benefit from centralized, trusted solutions like BICS’ Service Hub.  

These use cases highlight why 5G SA roaming is more than a technical upgrade—it’s the foundation for a world where mobility, performance, and security converge. As operators refine their roaming strategies, they must: 

• Choose scalable models like a Service Hub to handle emerging demands. 
• Adopt flexible architectures that simplify outsourcing for value-added services like sponsored roaming, Analytics and Business Intelligence tools and more. 
• Prioritize security frameworks like TLS hop-by-hop that balance performance and protection.

BICS’ 5G SA Service Hub is designed to simplify and accelerate the deployment of 5G SA roaming. Key features include: 

• One-click roaming management: The Service Hub provides operators with a centralized portal to implement and manage their roaming relations and certificates effortlessly. This one-click management approach eliminates manual, time-intensive processes, ensuring faster time to market for new roaming agreements without the need for technical knowledge. 

• Comprehensive customer support: Operators benefit from 24/7 customer support and robust customer relationship management tools, ensuring that any issues are resolved quickly and efficiently. 

• Easy scalability: The Service Hub is built to scale seamlessly into new geographies, allowing operators to expand their global footprint without significant resource reallocation or infrastructure changes. 

• Secure, low-latency connectivity: By integrating into BICS’ extensive IPX backbone, the Service Hub provides maximum security with regional and local breakout options, ensuring the lowest possible latency for critical applications. 

• Network and technology agnostic: The hub’s flexibility enables operators to manage their roaming relations regardless of their network architecture or underlying technologies. 

• Network slicing support and regional and local break-out options are made possible thanks to our expansive IPX backbone network, which boasts the most on-net mobile networks across the globe. This enables us to deliver the true promise of 5G SA roaming. In a world where roaming is no longer just about connectivity but an enabler of innovation, the BICS 5G SA Service Hub sets operators up for success and empowers them to transform the challenges of 5G SA roaming into opportunities for growth and differentiation.