Modern smartphones, and in particular popular models from Xiaomi and Redmi, are equipped with a variety of features, the icons of which often appear at the top of the screen, but remain incomprehensible to most users. One such indicator is the VoLTE inscription, which can appear on its own after a firmware update or change. SIM-Many gadget owners start to panic, believing that it is a virus or a paid service, when in fact it is an advanced voice technology.
In this article, we will discuss in detail what VoLTE means in the context of Xiaomi phones, why this feature is critical for communication quality in the context of the development of 4G and 5G networks, and also consider methods of its forced activation if the operator does not provide it by default. Understanding the principles of this technology will allow you to enjoy crystal clear sound during a conversation while using fast Internet without switching network modes.
It is worth noting that the introduction of Voice over LTE has become the de facto standard for modern mobile operators, gradually displacing outdated 2G and 3G standards. If you are the owner of a Redmi Note device or the flagship Xiaomi Mi series, ignoring the settings of this feature can lead to a decrease in communication quality in the future, when the old towers are finally decommissioned.
Technology and benefits of Voice over LTE
VoLTE stands for Voice over Long-Term Evolution, which literally means “voice over LTE.” Traditionally, mobile phones used second (2G) and third (3G) generations networks exclusively for voice calls, switching to them every time you initiating a call, even if you were sitting quietly on the Internet over 4G. VoLTE technology allows you to transmit voice stream as normal data over a fourth-generation network using the IP protocol, which eliminates the need for constant switching between communication standards.
The main advantage of this technology for Xiaomi smartphone users is the ability to use high-speed Internet and voice communication simultaneously. In the past, when an incoming 4G call was made, the Internet connection often fell to EDGE or 3G, which interrupted page loading or navigation. With HD Voice enabled, your smartphone remains on the LTE network, providing stable access to data.
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Use VoLTE in 4G areas of uncertainty: the technology often allows you to make calls where a regular 3G network no longer catches the signal, thanks to better penetration of the LTE signal into the premises.
In addition, VoLTE audio quality is significantly superior to standard phone calls; the frequency range of sound transmitted is expanded, voices become more natural, metallic shades and noises disappear; to realize this potential, three components must work in concert: a support smartphone (for example, Redmi Note 10), an operator’s tariff plan and a configured base station.
How to check the support of the function of your device
Before you try to activate hidden features, you need to make sure that your particular device is technically capable of working with Voice over LTE. Most modern Xiaomi models released after 2018 have built-in modems that support this technology, but the software (firmware) can block access to settings depending on the region of sale.
The easiest way to test is visual. SIM-A map of the operator that claims to support VoLTE in your region, and look at the status bar. 4G or LTE If the icon is not available, it does not always mean that there is no support; manual activation is often required through an engineering menu or special codes.
Hidden check through the engineering menu
It’s also worth considering that some global versions of MIUI or HyperOS firmware may not have pre-installed profiles for local carriers, even if the phone’s hardware is fully ready to go, and users often resort to changing regions in settings or installing third-party apps to activate hidden flags.
Instructions for enabling VoLTE on Xiaomi and Redmi
Activation of the feature on Xiaomi devices is usually automatic, but in some cases, user intervention is required. The standard way is through the settings of the mobile network, however, the interface may differ depending on the version of the shell. → SIM-maps and mobile networks, select the desired SIM card and find the switch "Use VoLTE».
☑️ Checklist of VoLTE activation
If a standard switch is not available, you can try using hidden code to access the advanced settings. In the Phone app, dial the combination ##86583##. The screen should show the message "VoLTE carrier check was DISABLED" (or ENABLED), which means that the software locks the operator check, then reboot the device and check for the icon.
It’s important to understand that not all carriers and planners support this feature for free, and some mobile companies require an option or a change to a specific tariff. You can check this information in the operator’s personal account or by calling the support service, clarifying the compatibility of your own. SIM-net-card LTE.
Solution: the icon is missing or does not appear
The situation where the VoLTE icon suddenly disappears after a system update or location change is quite common among Redmi users. Often this is due to the fact that the phone loses registration in the IMS (IP Multimedia Subsystem) of the operator’s network. The first step in solving the problem should be to switch the network mode: set the value “Only 4G” (or LTE), wait a few seconds, and then return the 4G/3G/2G (auto) mode.
⚠️ Warning: Forced switching to “Only” mode 4G» This can result in a complete loss of the ability to make and receive calls if there is no voice coverage in your area. LTE. Use this method only for diagnosis!
Another reason for the disappearance of the function may be the incorrect operation of the access point. APN. Go to the mobile network settings, select your own SIM-Map, go to "Access Points (APN)» And reset the settings to factory values, and then re-enter the settings that your carrier provided, or just reset the phone so that it automatically loads the current profiles.
If the software methods do not help, the problem may lie in the very SIM-Old maps that were used in the old days. 2G/3G, may not have the necessary memory or firmware to work with modern standards IMS. In this case, the only solution is to replace SIM-cards for a new one in the operator’s cabin, which is usually done free of charge while saving the number.
Comparison of voice communication technologies
To better understand VoLTE’s place in the mobile ecosystem, it’s useful to compare it to other voice technologies. Below is a table showing the key differences between traditional methods and modern standards used in Xiaomi smartphones.
| Characteristics | 2G / 3G (CS Voice) | VoLTE (4G) | VoWiFi |
|---|---|---|---|
| Sound quality | Low/Mediocre | High (HD) | High (HD) |
| Connection speed | 2-5 seconds | Instantly (< 1 sec) | Instantly. |
| Simultaneous Internet | No (falls to 2G/3G) | Yes (powers 4G/5G) | Yeah (via Wi-Fi) |
| Battery consumption | Medium. | Low (more effective) | Depends on the Wi-Fi signal. |
As you can see from the table, the transition to VoLTE gives a significant increase not only in audio quality, but also in connection speed. In addition, this technology is more energy efficient, since the modem does not need to constantly switch between frequencies of different standards, which positively affects the battery life of your Xiaomi.
VoWiFi (Voice over WiFi) technology, which is often paired with VoLTE, allows you to make calls over a Wi-Fi network in places where mobile communication is absent or very weak (basements, remote suburban areas), if your operator supports both standards, the phone will automatically switch between them, ensuring continuity of communication.
Impact of firmware and region on function
Xiaomi releases its devices with different types of firmware: global (Global), European (EEA), Russian (RU) and Chinese (CN). The availability and operation of VoLTE function depends on which version of the software is installed on your device. For example, on global firmware, the list of supported operators may be wider, but at the same time, specific settings for local Russian or Ukrainian operators may not be specific.
Users who reflash their smartphones from the Chinese version to the global (or vice versa) often experience the disappearance of the VoLTE icon. carrier_policy.xml, In some cases, the restoration of the function requires editing system files through root rights, which is a complex and risky procedure.
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Changing the region in the phone settings (such as India or Singapore) sometimes helps unlock hidden VoLTE carriers, as the technology has been more widely adopted in these countries.
It is also worth considering that with the release of the new HyperOS shell, Xiaomi has changed some algorithms for working with the network. If after the update the firmware began to work unstable in terms of communication, it makes sense to reset the network settings or, in extreme cases, completely reset the device with a clean installation of the current version of the software.