5G Non-Standalone Architecture (NSA), which is built upon existing 4G infrastructure and has become prevalent in much of the United States, is also gaining traction around the world.  However, true 5G, 5G Standalone Architecture (SA), the proverbial promised land of New Radio network architecture, is still in its early phases. 5G SA roaming service will offer higher broadband speeds with Enhanced Mobile Broadband (eMBB), Massive IoT, Ultra Low Latency (URLLC), Massive Machine Type Communications (mMTC) and Network Slicing in turn unlocking use cases such as smart cities, augmented reality and immersive experiences, industry automation and manufacturing, autonomous vehicles and public transport, and 5G drones. The applications are endless.

Current 5G SA Roaming Landscape

Building out 5G networks requires new levels of security protocols called SEPP (Security Edge Protection Proxy). SEPP was defined by 3GPP and GSMA (TS 29.573 and NG 113 respectively) to ensure end-to-end data integrity and confidentiality between 5G roaming partners. While security remains a top priority for 5G roaming, operators must also consider the orchestration of new 5G features, such as network slicing. Network Slicing can provide operators with optimization opportunities of their network by parsing network resources with varying levels of security for customer specific services and features and will help to manage network resources for the massive influx of IoT + edge computing devices.

Another 5G challenge will be gaps in roaming coverage due to lack of overlap between 5G SA networks enabled for roaming and existing LTE/VoLTE roaming coverage. Tier 1 operators will be able to justify investing in 5G New Radio network infrastructure while most rural and smaller operators may lag behind. Rural operators will also struggle to rationalize upgrading to 5G SA as they are still implementing Voice over LTE (VoLTE). We see 3G turn down happening on a rapid scale, VoLTE roaming very slowly increasing, and VoNR (voice-over NR) prioritized behind VoLTE for now, risking ubiquitous mobile voice global footprint. Overall, there are only a few 5G SA operators commercially launching roaming interoperability, therefore seamless global roaming of 5G SA is unrealistic currently. True seamless global roaming for 5G SA will take much time to achieve due to challenges with 5G NR investment, varying operator prioritization timelines and current focus on 3G turndown and VoLTE,

The Billing Evolution

Compared to 3G and 4G, 5G charging is more flexible, presenting operators with new models of wholesale billing. Currently, operators utilize TAP to exchange roaming billing records for settlement. TAP is limited in flexibility although still relevant for most operators and their current charging models. With 5G, operators are required to transition to Billing and Charging Evolution (BCE), where they will be able to offer more flexible wholesale billing. We recently looked at this in more detail in this blog.

Private 5G Roaming

5G SA roaming will also enable a world of opportunities for private 5G roaming, which offers enterprises and organizations such as airports, military bases, and sports stadiums the reliability, security, and scalability to consistently achieve better quality subscriber experience and allow businesses to set up closed environments for IoT and telco needs.

To prepare for the rollout of 5G SA roaming, TNS is working with partners and customers to define new paradigms in 5G strategic initiatives. In December, TNS announced a collaboration with Cellusys, a leading global solutions provider for research, development, and testing of roaming and security solutions for 5G networks. Together, the companies will utilize TNS’ 5G Innovation Lab to develop and test solutions that combine TNS’ capabilities in steering of 3G, 4G, and soon-to-be-5G roaming traffic with Cellusys’ security solutions, including signaling and its SMS firewall, and other services for national and regional network operators. TNS and Cellusys are collaborating in defining a first-of-its-kind, cross-generational security foundation for seamless yet effective protection against vulnerabilities in 3G, 4G, and 5G domains.

To learn more about 5G SA and how it will impact the roaming landscape, be sure to check out our other resources.

Nina is Director of Product Management at TNS, with specific responsibility for roaming product strategy and development.