VoLTE on Xiaomi and Redmi - how to enable or disable what the icon on the phone screen means

Since the days of GSM communications, we have become accustomed to a certain nature of voice transmission over cellular networks and do not even notice how simple and compressed the transmitted sound is.

Fortunately, technology is developing rapidly and with the arrival of 4G, or LTE, in Russia, we can enjoy high quality voice transmission during a phone call using almost any Xiaomi (Redmi) phone that supports the LTE standard.
VoLTE (Voice over LTE) technology helps us with this - this method uses a packet architecture very similar to that used to transmit data on the Internet.

This became possible thanks to the high throughput of LTE and, most importantly, data transmission density.

But in order for you to be able to talk to your interlocutor via Xiaomi via VoLTE, you need to meet three prerequisites:

Your Xiaomi must support VoLTE (there is a 90% chance of support);
The interlocutor’s phone must support it, and it must be turned on;
The cellular operator must provide support for VoLTE.

And if there are no problems with phones that can use VoLTE now; all devices released over the last 3 years are capable of this, then with operators the question is different.

Even if there is a 4G network in your region and you download files at high speed through it, this does not mean that the operator has configured it to work with VoLTE.

You can find out about this only by calling the support service and asking if this technology works in your city or locality.

What is VoLTE and how does it work?

To understand this issue, we first need to understand what Long-Term Evolution technology is (the so-called “long-term evolution”) or, more simply, LTE (often referred to as 4G LTE), which has been present in our lives for quite some time.

LTE is a modern standard for wireless high-speed data transmission for smartphones and other terminals that work with data. According to the relevant decision of the International Telecommunication Union, the LTE standard can be referred to as 4G. However, in reality it is just an improved 3G that meets a number of 4G requirements. Thanks to this communication standard, users have the opportunity to download and upload various large files on the Internet, and watch online videos in high quality without delays. Thus, until recently, the technology was focused only on data transmission and was not used in voice calls. This means that even if 4G is turned on on your smartphone, every call is automatically transferred to 3G or 2G. Such a significant limitation has existed for quite a long time.

The entry into the VoLTE market helped make the 4G/LTE communication standard full-fledged. Literally from English Voice over Long-Term Evolution (or Voice over LTE), which translated means “Voice over LTE”. The technology allows you to make or receive calls over a high-speed IP channel, turning voice into a data stream.

As stated, the purity and speed of sound is 3 times faster than 3G and 6 times faster than 2G. As for the speed of establishing the connection itself, it takes 1–1.5 seconds, since the gadget no longer needs to switch from one standard to another and spend additional time. With all this, all Russian cellular operators charge VoLTE calls as usual - no additional fees are charged.

LTE Features

With the advent of each new generation of cellular communication, we could notice many changes. For the average user, an increase in bandwidth and, in general, “Internet speed” will be enough, but behind this lies a huge number of other changes. LTE technology has a number of features:

The minimum delay in data transmission can reach only 2 milliseconds.
Possibility of working together with older cellular communication standards. For example, you can start a conversation with someone while in LTE coverage and continue the conversation without any major problems by switching to 2G/3G.
Completely new packet switching radio interface.
There is support for both TDD and FDD (better compatibility with different types of communication).
Each 5 MHz cell can have a minimum of 200 active clients .

Advantages and disadvantages of technology

There are several significant advantages:

Improved voice quality by supporting special HD Voice codecs. As is known, in 3G and GSM communication standards, audio data transmission is limited to 16 Kbps, and sound is transmitted at a frequency of up to 3400 Hz. Thanks to the added codec, these restrictions are removed. The sound range, depending on network coverage, can increase to 7000 Hz and even more. Users notice that the sound quality is much clearer and clearer, the connection occurs without interference or distortion, and this applies even when one of the connected smartphones does not have VoLTE.
Work with data on the Internet and make simultaneous calls. Due to the operation of a smartphone with VoLTE mode enabled, the user has the opportunity to talk on the phone and at the same time, for example, use a mobile navigator to navigate a new area, view the news feed on a favorite social network, download movies, and so on. And in the case of a regular call, the phone switches to the 3G or GSM network and access to the Internet becomes impossible. Or the mobile Internet turns off completely during the call.
Communication channels are unloaded. There are benefits here not only for the subscriber, but also for the operator himself. Thanks to the VoLTE standard, one operator base station is capable of serving 3 times more subscribers than in the case of 3G. Therefore, in practice, a much smaller number of failures and communication interruptions are observed.
Small savings in smartphone battery power. Calling with VoLTE uses less battery power than calling with GSM. This happens due to the DRX mode. In this mode, the phone receives signals at certain intervals, and this does not degrade the quality of communication, but on the contrary, it saves a little battery energy, since the phone’s antenna is turned off during these breaks.

There are also some disadvantages:

Although the main cellular operators in Russia have begun implementing the technology in their networks for several years now, the geographic coverage remains small, especially in Beeline, Tele2 and Motiv Telecom. Therefore, for all subscribers from regions that still do not support 4G, there is no benefit from VoLTE.
By default, VoLTE mode is blocked on many Xiaomi smartphones. If desired, the user can unlock it (by sending a USSD request *#*#86583#*#*, which is discussed in detail below in the section on enabling and using), and the corresponding item will appear in the device settings menu.
Crystal clear sound during a call and the effect that the interlocutor is nearby can only be achieved if both subscribers support this communication standard.

Where can it be used?

The first, commercially called 4G protocols produced, however, much lower speeds than those provided and stated by international standards, but after the introduction of the LTE format, speeds have already improved significantly and reached the values specified in the standards. The commercial name designated them as 4G+.

The largest cellular operator MTS has currently created and is expanding the largest 4G LTE network of base stations. As of September 2021, there are more than 27,000 of them throughout the country and their number is constantly growing. You can see a map of the current 4G LTE network coverage across the country at the top of this page.

The introduction by MTS of more modern LTE-1800 base stations has allowed it to significantly outpace its competitors, since such a station provides coverage 3 to 4 times larger in diameter than simpler and older bases.

What you need to use the technology

To make voice calls over VoLTE, both your smartphone and your mobile operator need to support this technology. As for the manufacturer Xiaomi, almost all phone models in the Mi and Redmi line have support. Also, the SIM card itself must be suitable for the 4G network. If your SIM card is outdated, then you can change it to a new one completely free of charge at any salon of your operator. It is desirable, but not mandatory, that the software version on your smartphone be updated to the latest.

List of Russian operators that provide VoLTE service in different sets of services or in separate tariff plans. Also regions of the country where it is possible to use this type of communication.

Unblocking

To remove the blocking, those users who live in Russia will have to perform a special manipulation. To do this, dial a combination of the following characters on your smartphone: *#*#86583#*#*, then a notification will appear that the function is unlocked. After this, the required item should appear in the menu.

Currently, smartphones that support the new technology are entering the Russian market with this function blocked. Therefore, you don’t have to rush to buy a Chinese Xiaomi phone. Other flagship users who have already used the option must put up with the unpleasant situation and wait for new updates.

How to enable VoLTE and use it on a Xiaomi/Redmi phone

Activating the function on your smartphone is quite easy. For this:

Open Settings.
Go to the "SIM cards and mobile networks" section. In some smartphone models and versions of MIUI, the “Enable/Disable” VoLTE button is available directly in this general section. In others, you need to select a specific SIM card and look for the switch in its settings.
Near the “Enable VoLTE” or “VoLTE HD Call” item, move the slider to the active state and get improved quality of voice and video calls.

If you do not see the corresponding switch in the settings, then the function is hidden and needs to be unlocked. For this:

Start dialing mode and enter the special USSD request *#*#86583#*#*.
A small window will appear on the screen with the notification “Volte carrier check was disabled”. This means that the functionality has been blocked. Now the required switch should appear in the SIM card settings. Next, repeat the steps described above in the activation instructions.

There is another way to activate:

In dialing mode, enter the combination *#*#4636#*#*. Please note that this combination will not work on all Xiaomi and Redmi smartphones.
A window will pop up where you need to select “Phone Information”. If you have a model with support for two SIM cards, accordingly, the system will offer a choice of “Phone Information 1” and “Phone Information 2”. These are the first and second SIM cards.
You need to select the one you need and in the menu that appears, set the slider to the active state opposite “VoLTE synchronization is enabled.”

Note! If you need to make a call using VoLTE to a landline phone, be sure to dial the number in this format: +7-area code-phone number. By dialing the number in short format, the call will automatically be transferred to the 3G or 2G network depending on your current location.

general description

VoLTE is a technology that transmits voice over LTE networks. Thanks to this, you can ensure a fast connection for users without lags or delays during a call. The main advantages include:

High sound quality, which cannot be said about GSM or 3G. This is because in older versions of data transmission the voice transmission speed is limited to 16 kilobits per second. The new VoLTE technology is completely free of this drawback;
The ability to make free calls to those people who use tariffs with unlimited Internet. In Russia, operators Megafon, Tele2, MTS, Beeline offer this opportunity;
Very fast connection of subscribers. This is explained by the fact that the two devices synchronize with each other directly, without establishing a dial-up connection;
VoLTE increases the capacity of the cellular network several times compared to 3G, which reduces the likelihood of a station reboot;
At the same time, you can transmit not only voice messages, but also data.

Although the new technology has a small number of disadvantages, they must also be highlighted:

Too much load on the smartphone. To correct the situation, you need to implement a new algorithm at the chipset level;
For the technology to work correctly, mobile operators must switch to it.

How to disable VoLTE on Xiaomi/Redmi

When VoLTE mode is enabled on the smartphone, the corresponding icon lights up at the top of the screen, notifying the user about this:

If you do not need this functionality to work, then it is easy to turn it off and thus remove the icon.

In Settings, go to the “SIM cards and mobile networks” or “Cellular communications” section (different models have different menu item names).
Find the VoLTE switch and set it to Off. Please note that on some models the switch is located in the settings section of a specific SIM card, and not in the general “SIM cards and mobile networks”.

Main problems when turning on

If your 4G voice function does not work, this could be for several reasons:

The smartphone does not support the technology. In this case, nothing can be changed. There are no third-party firmwares that would add the option to the phone.
In 2021, Xiaomi began blocking the VoLTE function in new versions of MIUI in some regions of the planet. This happened due to crash signals that were often received from users. However, there is a way to legally activate the functionality on your smartphone - use the combination *#*#86583#*#*, which has already been discussed in more detail above in the article.
The mobile operator does not support VoLTE in its networks. Nothing can be done about this. Either wait for support to appear, or change the operator.
The SIM card itself does not support 4G networks. Each operator has special digital commands that allow you to find out this information or view it in the subscriber’s personal account. If the SIM card is out of date, the subscriber can contact the nearest store of his operator and change the SIM card to a new one while maintaining the number.
Operator restrictions. For some telecom operators, the function may not automatically work if certain options are enabled on the number. For example, “Melody for the buzzer” or “Anti-determinant”. In this case, it is recommended to call the operator and find out whether there are any restrictions on the operation of VoLTE on certain tariff offers.

Which operators provide in Russia

All leading companies provide subscribers with this opportunity. Operators also provide users with modems and pocket routers to access the network.

Megafon has a wide coverage area, but a higher cost of services, unlike its competitors. Offers up to 40 GB monthly; a separate option is connected to access the Internet via LTE.
MTS has a smaller coverage area. The subscription fee for communication services is lower than that of the previous competitor, and volumes are limited to 25 GB.
Beeline provides a special SIM card with LTE support. It is worth noting that the coverage area of this operator is wider than that of MTS.
Tele2 is also introducing LTE. But so far access is only in large cities.