T-Mobile launched Voice over 5G (VoNR) in the US, allowing customers to make and receive voice calls over a 5G connection.

The service is only available in two cities: Portland, Oregon, and Salt Lake City, Utah, but broader deployment of the technology will improve the efficiency of next-generation networks and reduce reliance on 4G.

If voice traffic can be routed over a separate 5G network (5G SA) instead of LTE, devices do not need to switch network technologies during calls, which means applications can benefit from 5G without interruption.

Broadband 5G FWA

VoNR harnesses the full potential of 5G SA because operators do not need to maintain a parallel LTE radio network. Although 4G and 5G are expected to coexist for some time, operators will be able to free up network and spectrum resources for next-generation technologies.

The same logic applied when operators implemented Voice over LTE (VoLTE) technology a decade ago. VoLTE added the ability to carry voice traffic over 4G, improving quality and reducing reliance on 3G.

With VoNR, T-Mobile says customers won't notice anything different, except that calls can connect faster than with 4G.

“T-Mobile is setting the standard for carriers around the world as we drive the industry forward; now we are starting to roll out another critical service on 5G,” said Neville Ray, president of technology at T-Mobile.

“5G is already driving new levels of engagement, transforming the way our customers use their smartphones and bringing unprecedented connectivity to areas that desperately need it. And it will only get better thanks to the amazing team at T-Mobile and our partners who tirelessly innovate and improve 5G capabilities every day.

Most early 5G networks were based on non-standalone 5G (5G NSA), which uses new radio technologies but still relies on the underlying 4G core.

5G SA is powered by a new cloud-based virtual core that allows data to be processed closer to the point of collection and enables features such as network cutoff. This enables guaranteed speeds, higher reliability and ultra-low latency, qualities that will be essential to deliver the most revolutionary 5G applications.