T-Mobile has just announced that it's deployed Voice Over New Radio (or VoNR) for its 5G network in parts of Portland, OR and Salt Lake City, UT. Although this marks the first commercial availability of the technology, which allows you to place a call over a 5G connection without falling back on LTE, the functionality is limited to last year's Galaxy S21 for now.

This might sound like a bunch of uninteresting acronyms drizzled with some 5G references, but it's actually going to be something customers have to pay attention to in the future, as they had to with VoLTE. Many of our readers are familiar with that one, if not for what it does (letting you place a voice call over an LTE connection), then for the headache it can sometimes cause when bringing an unlocked phone to certain carriers. Some carriers maintain a somewhat rigid allowlist of devices certified to work with their VoLTE implementations, which can cause problems if you're dragging an unusual model around.

VoNR essentially offers similar benefits to VoLTE but as applied to 5G. A lot of the early 5G networks and devices only worked when using LTE as a backbone — sure, you got the faster data connection that 5G offered, but certain features and functionality (even including basic network authentication) still required that you have that other connection to work. So-called "Standalone" 5G deployments which don't rely on that backbone connection are ongoing and will ultimately rely on technologies like this. T-Mobile started rolling its standalone 5G out years ago, but there was still always a requirement to use an "LTE anchor" for voice calls, and now even that issue is starting to go away.

With a compatible device and in one of the compatible areas, T-Mobile subscribers with a Galaxy S21 can now place a voice call directly via 5G. T-Mobile claims this will also improve call set-up times (that means less of a delay between dialing and ringing). Also importantly, T-Mobile says the change will eventually allow the company to better and more intelligently allocate network resources via a practice called network slicing, made possible by 5G and moving more network services onto it. Slicing lets the company better utilize its network capacity and could provide customers with greater reliability for specialized services, among other potential benefits.

If you're curious as to why T-Mobile is limiting this to the year-and-a-half-old Galaxy S21 and not more recent models, President of Technology Neville Ray says that's simply because they've been working on the feature for longer than the S22 has been available, and the S21 was used for testing. However, the functionality will expand to more phones and more markets later in the year, with the Galaxy S22 already called out as explicitly planned.

For most customers, even most T-Mobile customers, the news may not seem exciting in itself, but switching more legacy functionality over to 5G will be a long-term net benefit, especially now that regulators and standards bodies are already looking to the future and 6G.