It is exciting to follow the constant evolution of network technology, but only if you have the means to stay updated with new developments. In our industry, that means buying new smartphones, routers, and carrier plans. Plus, you need to make sure that what you buy is really compatible with the network you’re paying for. This week has once again reminded us of the importance of network compatibility as we remember that both AT&T and T-Mobile will eventually shut down their 3G networks. This should come as no surprise since both operators are in the process of implementing their 5G networks, but it is important to note due to the complicated nature of VoLTE on Android.
If you are not familiar with VoLTE, it means “Voice over LTE” and it is exactly what it sounds like. Phone calls are routed through a 4G LTE connection instead of 2G or 3G. A few years ago, this was seen as a big problem since the higher 4G LTE bandwidth means that more data can be transmitted, resulting in reduced compression of voice data and therefore better quality. call for both parties. VoLTE is pretty standard today, with almost all of the major carriers that have implemented it and all devices with cellular modems that support the technology. In fact, T-Mobile’s first quarter 2020 earnings report states that “VoLTE comprised 91% of total voice calls” on the network. Many operators have already closed their legacy 2G networks because the vast majority of customers have upgraded to devices that support newer network technologies, and operators are also preparing to close their 3G networks.
The present day, AndroidPolice posted a screenshot of an internal T-Mobile advisory revealing that the operator will require VoLTE for all devices connecting to its 4G LTE and 5G networks. The publication also reported on emails that were sent to AT&T customers informing them that their phones will eventually be incompatible with the operator’s network. Here’s what you need to know about the upcoming shutdown of T-Mobile and AT&T 3G voice networks.
T-Mobile VoLTE Requirement – Coming Soon
T-Mobile VoLTE Device Compatibility Requirements. Source: T-Mobile Via: AndroidPolice.
Effective August 4, 2020, T-Mobile will stop activating new devices that do not support VoLTE on its network. T-Mobile says that all the devices on its current lineup (i.e. devices sold through them) are compatible with VoLTE.
Starting in January 2021, any device that does not support VoLTE on T-Mobile will no longer be able to connect to the operator’s 4G LTE or 5G network. Existing T-Mobile and Metro by T-Mobile customers (formerly known as MetroPCS) who activate a non-VoLTE compatible device before August 4 will be informed by text message that their device will be incompatible with the network from January from 2021.
Although not yet confirmed, some devices purchased through Sprint may be affected by this change. Sprint has always required certification for devices to connect to its network, and that certification has included VoLTE support. However, T-Mobile is in the process of reorganizing Sprint’s network to expand its own 5G network, so some Sprint devices may not support VoLTE with the new T-Mobile network. We also don’t know how this change will affect devices from the myriad other MVNOs that use the T-Mobile network, including Ting, Consumer Cellular, and Mint Mobile.
T-Mobile issued the following statement to AndroidPolice Regarding this notice:
We are making great progress in building a truly transformative national 5G network. As part of that, we will gradually phase out some old technologies over time to free up even more capacity for LTE and 5G. In preparation for that and to provide customers with the best experience, those activating new lines on T-Mobile will need a VoLTE-compatible device, which is all we’ve offered for years and represents the overwhelming majority of devices on the network. .
However, the operator declined to explicitly confirm the timeline of its shutdown of the 2G and 3G voice network.
AT&T 3G Shutdown: Coming February 2022
Earlier this week, AT&T (bad) warned many customers that they should update their smartphones soon as their devices will soon be incompatible with the operator’s network. AT&T sent emails to customers saying their device “is not compatible with the new network and [they] you need to replace it to continue receiving service. “The part that AT&T did not explicitly mention to customers is that they will not be affected by this change until February 2022. The email, as drafted, clearly suggests that customers need to take urgent action to update your device, even going through outlining the steps to “easily” get a new device.
To your credit, AT&T it is at least informing customers of its impending 3G network shutdown long before T-Mobile, but they did incredibly wrong. AT&T provided a statement to AndroidPolice to clarify that this email was the first of many that he plans to send to customers to keep them informed about the impending closure of the operator’s 3G network. Here is the statement that the carrier sent to the post:
This email was one of many planned to keep customers informed about the closure of our 3G network in early 2022. It should have included the date that certain devices would no longer be compatible. We apologize for any confusion this may have caused and will become clearer in future updates.
Then AT&T, like T-Mobile, will require that all devices connected to its network be compatible with VoLTE. AT&T calls this “HD Voice” and, like T-Mobile, will block voice. and data service for phones that do not support it. AT&T, unlike T-Mobile, is whitelisted for VoLTE / HD Voice. That whitelist, available here, includes Essential Phone, all Google Pixel phones from Pixel 2, LG G7 and V35, 9 Motorola devices, OnePlus 7 Pro and 7T Pro, and all Samsung Galaxy flagships since the S8.
What this means for BYOD, unlocked devices, and custom ROMs
If you’ve bought a recent smartphone directly from AT&T or T-Mobile, chances are good that you have nothing to worry about here. However, if you’re using an unlocked device or a device in a custom ROM, then you’ll want to pay attention to what’s next. Since AT&T is whitelisted for VoLTE compatibility, you will not be able to send BYOD to the operator beginning February 2022 unless the operator changes its practices or whitelists many more devices. There’s no reason they can’t do it, VoLTE is a standard protocol after all, but so far they haven’t. There is nothing you, the device manufacturer, or a custom ROM developer / modifier can do about it.
While T-Mobile, on the other hand, doesn’t whitelist for VoLTE compatibility, many directly unlocked devices don’t support it anyway. The recently announced ASUS ROG Phone 3 currently does not support VoLTE on the network, for example. Not that these phones hypocrisy Supports VoLTE on T-Mobile, it’s just that the device manufacturer hasn’t done the work to fully endorse it. The modifiers on our ROG Phone II forums have figured out the steps necessary to enable VoLTE on T-Mobile, proving that a little more work at the factory could enable support.
Theoretically, as long as your Android device has a working IMS (IP Multimedia Subsystem) stack, it should support VoLTE on T-Mobile (but not AT&T due to its whitelisting system). Typical Android devices with Qualcomm modems ship with a prime app that ties the Radio Interface Layer (RIL) and IMS together, which developers carry in their custom ROMs to enable VoLTE support. LineageOS, for example, requires maintainers to support VoLTE if the stock ROM supports it. If the stock ROM doesn’t support it, it’s unlikely that you can use the device on AT&T or T-Mobile once they turn off their 3G networks.
One more thing we should talk about is the support for phones bought abroad. Chances are if your phone has the correct hardware (which almost everyone has) and the correct IMS settings (a little more iffy) to support VoLTE on T-Mobile and AT&T, you will be able to make VoLTE calls on both networks as long as your provider network services have a roaming agreement.
How to check if your phone supports VoLTE
There is a fairly easy way to check if your phone supports VoLTE at your current provider. Just install the “Network Mode Universal” app from the Google Play Store, turn on mobile data (and turn off Wi-Fi so you don’t accidentally turn on VoWiFi), and make a phone call to another number. If the “Voice Network Type” line shows “LTE”, then your phone call is routed through LTE. Congratulations, your phone supports VoLTE on your operator! If you see something other than LTE, like GSM, WCDMA, UMTS, or just 3G, then your phone doesn’t support VoLTE on the network. In this case, talk to your operator’s customer service for your next options.
Thanks to AndroidPolice for bringing this application to our attention.
