What is VoLTE and why should I care about it?
Here in the U.S., most carriers have rolled out the red carpet for Voice over LTE. If it is available in your area and through your carriers, taking advantage of the upgrade currently depends on your having the right hardware. Once you have everything you need, setting VoLTE up on your phone is very easy and well worth it.
Let's take a deeper look.
What is VoLTE?
As the name suggests, Voice over LTE is what happens when your carriers allows you to place a phone call over your LTE connection instead of the more common voice networks. Verizon Wireless, for example, traditionally used 1XRTT for all of your voice calls, relying on LTE for data. This used to be why Verizon phones couldn't simultaneously use voice and data. AT&T and T-Mobile, which relied on a combination of LTE for data and HSPA+ for calls, would drop down to a 3G signal when talking to someone on the other line. With VoLTE, neither of these scenarios are necessary anymore.
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 traveling both ways. When you are on a call with someone else who is using VoLTE, you immediately notice the difference in call quality on both ends. You'll also notice the calls connect faster if you are calling someone near you, and while that's not a feature worth bragging about it's a cool thing to test for yourself.
How can I use it VoLTE?
Most major U.S. and Canadian carriers have rolled out VoLTE to some extent, as of September 2016.
Verizon rolled out VoLTE in September 2014, and has since been building it into most new high-end devices from Samsung, LG, and Motorola. Consolidated under its HD Voice brand, VoLTE is rolled into video calling and Wi-Fi Calling, but all customers need to know is that a VoLTE-enabled device will be able to stay on LTE on a phone call, and connect to other cellphones and landlines at much higher qualities. Verizon also recently rolled out VoLTE support to prepaid devices.
AT&T rolled out VoLTE in May 2014, and most new devices support the protocol. Also bundled under its HD Voice brand (coincidence?), AT&T says that the higher-quality codec and reduced background noise that come with such calls are currently limited to other AT&T customers, but that it has worked with Verizon to test interoperability between networks.
T-Mobile rolled out VoLTE in May 2014, and says that over 50% of the calls made on its network use the new standard. Earlier this year, it appended EVS, Enhanced Voice Services, on top of the VoLTE standard, claiming to improve call quality, reliability, and connectivity speed. Most new T-Mobile phones support VoLTE out of the box, and the company has been great about updating its older devices to support it, should the hardware allow.
Sprint and US Cellular are in the testing stages for VoLTE, and have not yet rolled it out to customers. Sprint is in a unique position where it doesn't need VoLTE, since it has fewer customers than the other big carriers, but a comparable amount of spectrum, making it less essential to refarm the spectrum they currently use for voice calls to the more-efficient VoLTE standard. US Cellular wants to wait until VoLTE is mature enough to be revenue-positive for the company. Neither company has committed to a timeframe for public availability.
In Canada, Rogers, Bell, and Telus have rolled out VoLTE to some customers, though the two former have considerably wider support than Telus, which is limited to Alberta and British Columbia. The good news is that, unlike in the U.S., carrier interoperability was built into the carriers' plans, meaning that calls made between VoLTE users on Rogers and Bell will sound just as good as those made intra-network.
What else do I need to know?
One of the curious problems associated with VoLTE is accurately measuring usage to ensure that those on tight data budgets aren't getting ourselves in trouble by taking advantage of higher quality audio.
Today, all carriers count HD Voice/VoLTE calls towards the minutes in one's monthly bucket, and not data, even though VoLTE uses the same data network as video streaming or browsing the web. But for carriers like 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 1-minute video call uses about 6 - 8 MB of data," beware of that before making that video call — or just use Wi-Fi.
It's also worth noting that all carriers in this list also offer Wi-Fi calling, which routes regular voice calls through a Wi-Fi network in a seamless way that, in areas of poor cellular coverage, improves call quality and reliability.
While the VoLTE revolution has been slow and steady, it's good to see most U.S. and Canadian carriers beginning to take the benefits of the new technology more seriously, and ensure the experience is as seamless as possible for users like you.