VoLTE, which is short for Voice over Long-Term Evolution, is a technology utilized by phones and carriers to transmit our voices during calls. In fact, if you have a modern smartphone, you're probably already using it on a near-daily basis, even if you don't realize it. As carriers in the United States (both mainstream and MVNOs) continue to improve their 5G services, LTE (which is popularly called 4G) has become the default fallback option. VoLTE, as its name suggests, is based on LTE and is available across the vast majority of the country. Even if you have a newer smartphone but you're not already using VoLTE, it's a good idea to switch over to it.
Let's take a deeper look.
What is VoLTE?
As the name suggests, Voice over LTE enables you to place a regular phone call over your carrier's LTE network, instead of the older legacy voice networks. For example, Verizon Wireless used 1XRTT in years past for all voice calls, switching to LTE only for data usage like browsing the web. This used to be why older Verizon phones couldn't simultaneously use voice and data. Similarly, both AT&T and T-Mobile used to rely on a combination of LTE for data and HSPA+ for voice calls, and connections would drop down to 3G when talking to someone on the other line. With VoLTE, neither of these things are needed.
What both network types now have in common, thanks to VoLTE, is the ability to use more bandwidth to make phone calls with higher-quality audio that can easily travel both ways. When you're on a call with someone using VoLTE, you can immediately notice the difference in overall call quality on both ends. You might also notice your calls getting connected much faster.
Which U.S. carriers support VoLTE?
All of the three major US carriers, namely AT&T, T-Mobile, and Verizon, support VoLTE.
However, some carriers refer to VoLTE as 'HD Voice' for marketing reasons, since it results in increased fidelity compared to traditional cellular calls. At this point, most people making a call on a modern smartphone will be using HD Voice whether they know it or not. Most MVNOs and prepaid carriers utilize VoLTE for the majority of the calls and some, such as Visible, even require it.
Wi-Fi calling tech is nearly identical to HD Voice from the user's perspective, in that it uses a Wi-Fi data connection to complete the call instead of the LTE network. On all the carriers, you can expect an increase in call quality as long as your connection is solid. This can be especially important for people who work or live in the concrete brutalist buildings commonly built in the 70s and 80s, which often block outside cell signals.
Some prepaid carriers, like Visible, have already moved to an all-digital network for their services.
How can I use VoLTE?
Even as the carriers ramp up 5G deployment throughout the country, they continue to maintain their existing 4G LTE infrastructure to fill in the gaps in coverage. As such, every major carrier supports VoLTE these days, and the same is true for nearly all modern phones too. In fact, all 5G phones are backwards-compatible with 4G LTE (and thus VoLTE) as well.
On iPhones, the setting is usually a toggle in the main settings under Cellular, then Cellular Data Options. You might notice that when you change the selection, the network indicator on the phone resets.
On most newer Samsung phones, the option will be in the connections category in the phone's settings. On other phones, such as those from OnePlus, it's very similar to the option under the Wi-Fi & network category. Usually, you'll find this option under the 'Network' or similarly named setting.
A few crucial things need to go right for VoLTE to take effect, including having a good enough LTE connection with a tower that supports VoLTE. You'll also need a device that supports VoLTE. This is something that will need to be confirmed on each device on your carrier of choice, but as mentioned before, most phones released in the last couple of years should be compatible with absolutely no issues.
Perhaps the eventual goal for carriers is to move everyone over to calling on VoIP, or Voice over Internet Protocol. Once this happens, features like VoLTE, VoNR, and Wi-Fi calling will fall into the same category and allow high-quality calls when connected to a secure network source. This also includes standalone 5G, and as more efficient 5G networks mature, carriers are going to want their customers to stay on that tower as much as possible. It's worth mentioning that VoNR (which stands for Voice over New Radio) is often also called Vo5G (Voice over 5G) and is the successor to VoLTE, since it uses 5G network infrastructure.
What else do I need to know about VoLTE?
Today, almost all carriers offering unlimited talk and text include HD Voice or VoLTE calls in that bucket of services, even if they use the same network as video streaming or web browsing. But for carriers such as Verizon that support video calls under the VoLTE standard, the voice portion of a chat will use minutes, while the video portion will use data. Verizon says that "an average one-minute video call uses about 6-8 MB of data," so unless you're hanging on to an ancient small data plan, it's probably going to be a nonissue.
It's also worth noting that all major carriers, as well as the best MVNOs, offer Wi-Fi calling which routes regular voice calls through a Wi-Fi network in areas of poor cellular coverage or just to improve call quality and reliability. Wi-Fi calling has more hoops to jump through than VoLTE does on U.S. carriers — especially on AT&T — but it can be a very useful tool if you live near or in an area with spotty coverage.
Also, do keep in mind that VoLTE services might not be available if you're traveling internationally. Wi-Fi calling, however, should still be there.
While the VoLTE revolution has been slow and steady, it's mostly complete as both consumers and carriers look forward to 5G, the next big thing in town. It's good to see progress from mobile carriers, especially as spectrum becomes more valuable ahead of further 5G deployment.
Do I need to upgrade my phone to keep making calls?
Most people, even those still using much older phones without VoLTE support, will upgrade voluntarily before their network requires them to do so. However, if you have an older phone without VoLTE support and are just looking for stronger and more consistent performance, especially while traveling, upgrading to one of the best Android phones with support for VoLTE is a good move. Unsurprisingly, most of these phones are compatible with 5G networks as well.
If you bought a phone from a carrier, like AT&T, and tried to take it to another, like Verizon, there may be some incompatibility between software versions that make VoLTE not work properly.
In 2020, some AT&T customers were told that they needed to upgrade their phones to continue using the service. In fact, AT&T has already shut down its 3G network so affected customers should have already been upgraded to LTE-compatible devices. T-Mobile also took its 3G network down in 2022, so customers more than likely have already been upgraded to VoLTE phones.
AT&T isn't the first carrier to drop support for older phones, and it certainly won't be the last. The fact of the matter is that maintaining equipment for its legacy networks for the few customers who insist on using dated phones is a huge waste. While using a phone for longer is good for the environment, there's a point where the hardware just can't keep up with modern infrastructure.
