T-Mobile has achieved the world’s first 5G SA roaming connection, allowing its customers to carry a full standalone 5G experience across international borders. The carrier began its 5G journey with a fully independent 5G Standalone (SA) network built on a cloud-native 5G core, a decision that is now enabling advanced capabilities and performance gains for subscribers.
Unlike 5G Non-Standalone (5G NSA), which relies on existing 4G equipment as a base, 5G SA unlocks the full potential of 5G, delivering faster speeds and greater reliability. That distinction sits at the heart of this latest milestone.
Taking 5G across borders
Carriers typically partner with other providers to extend connectivity beyond their own coverage zones. Because 4G infrastructure is more widespread, roaming has usually defaulted to 4G or, at best, 5G NSA. T-Mobile has changed that by joining forces with India’s Jio, another early adopter of 5G SA, to establish the first 5G SA roaming connection. The interoperability is managed by global communications company Syniverse.
The agreement means T-Mobile customers travelling to India will benefit from the speeds and lower latency of 5G SA, rather than being limited to a slower 5G NSA or 4G network, and the same applies to Jio customers visiting the United States.
“This is a monumental step for global wireless, and T-Mobile is proud to lead it. Leave one country, land in another, and your 5G experience is just as seamless,” said Ankur Kapoor, T-Mobile’s Chief Network Officer, in September 2026.
Voice carried over 5G
The capability went live in August, and between 40% and 50% of combined roaming traffic has already moved to 5G SA. The functionality supports both data and voice through Voice over New Radio (VoNR), meaning voice communication is also carried over 5G networks.
Voice services are generally more complex to support than data, as they are highly sensitive to latency, mobility and network handovers. T-Mobile addressed these challenges by using a unified network infrastructure that handles both 5G SA and 4G traffic.
More partnerships ahead
Nearly 390 carriers have deployed 5G networks worldwide, of which only around 90 currently offer 5G SA. T-Mobile is in talks with several international carriers to expand 5G SA roaming to more countries. Because networks are not yet fully standalone, managing handoffs between 5G SA, 5G NSA and LTE remains a technical challenge.
Cross-border 5G SA is more than a demonstration of technical capability; it signals that experience continuity is becoming the new benchmark for providers. Currently, between 40% and 50% of the combined T-Mobile and Jio roaming traffic runs over 5G SA.
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Image: phonearena.com
