VoLTE on Xiaomi: what it is, how to turn it on and why it doesn’t work

Owners of Xiaomi, Redmi and POCO smartphones often encounter the acronym VoLTE in the status bar, but not everyone understands its real purpose. This technology radically changes the principle of voice transmission, transferring it from old analog channels to digital LTE format. As a result, voice calls become part of Internet traffic, which provides instant connection and crystal clear sound without background noise.

For users of Xiaomi devices, activating this feature is often a necessity, as carriers gradually turn off old 2G and 3G networks. If your device does not configure voice over LTE, you may lose the ability to make calls in areas with poor coverage of old standards. In this article, we will discuss in detail all the nuances of the technology, ways to force the activation of hidden menus and methods for eliminating common errors.

Many users confuse VoLTE with regular calls via instant messengers, but these are fundamentally different things: the technology is integrated directly into the standard phone book and does not require a separate application or Internet connection in the usual sense (it takes minutes of tariff, not megabytes).

Technological Essence: How It Works Inside the System

Voice over LTE is a packet-based voice traffic transmission over a fourth-generation network. Unlike traditional calls that use Circuit Switched, VoLTE uses packet switched, which allows Xiaomi’s smartphone to stay on a high-speed 4G network without switching to 3G or 2G mode during a conversation.

The main advantage is the use of high-quality codecs, such as AMR-WB (Adaptive Multi-Rate Wideband), the frequency band of the transmitted sound expands to 50-7000 Hz, which is twice the range of conventional telephony (300-3400 Hz), the voice of the interlocutor sounds natural, the effect of the "robot" and the metal sound characteristic of compressed audio in old networks disappears.

And it also allows you to use voice and data at the same time, and you can talk and download files at the same time, navigate a map, or play online games without dropping the speed to the top of the table. EDGE. This requires support from three components: the operator, SIM-map and device.

• 📡 The operator must maintain the standard IMS (IP Multimedia Subsystem on its network.
• 📱 Xiaomi smartphone should have the appropriate operator profile in the firmware.
• 💳 SIM-The map should be replaced with a format. USIM, if she's very old.

⚠️ Note: Even if your plan supports your HD-calls, without an active option in the phone settings or on the operator side, the function will not work.

It is important to understand that when you leave the 4G coverage area, the call can be interrupted or switched to 3G if you do not support SRVCC (Single Radio Voice Call Continuity) technology. Modern processors in Xiaomi devices cope with this switch almost imperceptibly to the user, but in older models there can be delays.

Verification of device and operator compatibility

Before attempting to activate hidden functions, you need to make sure your equipment is physically capable of working with the device. HD-Not all Redmi models or POCO, especially global versions, have unlocked engineering menu for Russian or Ukrainian operators by default.

The first step is to check the list of supported operators in your area, and the official list can be found on the manufacturer's website or in the model specifications on the MIUI website. Often, it happens that one operator works immediately, and another requires manual activation through the engineering menu.

In Global ROMs, some features may be trimmed due to licensing restrictions or lack of certification from local operators. Chinese versions (China ROM) usually have a wider set of supported profiles, but may not have Russian or the desired frequencies.

You can use Android's built-in tools to diagnose the current state of the network. Go to the settings menu and find information about the network. SIM-It often shows the status of "VoLTE" or "HD". If there is no such mark, the network 4G This means that the voice is transmitted through fallback. 3G.

• 🔍 Go to Settings. → The phone. → All specs.
• 📶 Find the line "Status" SIM-map".
• 🆔 Make sure the network type is installed in the preferred 4G (LTE).

Some virtual operators (MVNOs) running on Big Four networks may also not provide VoLTE service even if the core network supports it, in which case activation on the phone side will not work until the carrier opens access to your number.

Basic activation via the standard MIUI menu

The easiest and safest way to enable the feature is to use a standard shell interface. MIUI HyperOS: Manufacturers often hide the switch if they don't find a compatible switch. SIM-The map, but in the latest versions of the software it has become more accessible.

To start, open the Phone app and go to the call settings. If your operator is identified by the system as supported, you will see "Use VoLTE." In some cases, this switch may be located deeper in the mobile network menu.

If the switch is found and activated, the status bar should have an icon (often a phone handset labeled HD or 4G). After that, try to make a test call. Sound quality should improve markedly, and the connection should be installed faster.

⚠️ Warning: If the icon does not appear after switching on, try restarting the device or turning on and off flight mode.

If you don't have a switch on the standard menu, don't panic, which means that the system hasn't found the automatic configuration, and for those situations, there are advanced methods of setting up through the engineering menu, which we'll discuss later.

Advanced configuration through the engineering menu

If you can't activate VoLTE with standard methods, you'll have to use an engineering menu, which is a hidden part of the system that's designed for developers to test hardware, and it's accessed on Xiaomi via a special application or code.

On modern versions of Android, direct code entry ##4636## can be blocked, in which case you will need to install the "Activity Launcher" application or a special application "MTK Engineering Mode" (for MediaTek processors) from the Google Play store. For Snapdragon processors, the "Engineering Mode MTK" application or similar utilities are used.

The path to activation (example, may differ):


Phone Information → Set Preferred Network Type → LTE Only (not recommended for permanent use)




or




VoLTE Carrier Provisioning → Enable

You'll need to find a section on the engineering menu that's related to telephony, and you'll need to look for "VoLTE Provisioned" or "Enable VoLTE." After you tick or switch the switch, you'll need to restart your smartphone, and this method forces the modem to tell you that the service is activated.

It is worth noting that some global firmware may have their menus cut down, so the only alternative is to flash the device to a regional version (e.g. India or Russia) where support for operators is sewn into the system.

Comparison of voice transmission technologies

To get a good idea of the benefits, it's worth comparing VoLTE to other available technologies, and understanding the difference will help you assess the need for customization. Below is a table showing the key differences.

As you can see from the table, switching to VoLTE brings a significant increase in comfort. However, if you are in an area where 4G catches poorly and 3G works steadily, sometimes it makes sense to temporarily disable the feature to avoid constant reconnections and breaks.

VoWiFi (Voice over Wi-Fi) is a logical extension of VoLTE, allowing you to make calls through Wi-Fi hotspots. On Xiaomi smartphones, these features often activate together or require similar settings in the operator profile. If you have a bad network at home but you have Wi-Fi, this bundle will be a salvation.

💡

For maximum autonomy in standby mode, only turn on VoLTE, and use VoWiFi situationally, as a constant search for Wi-Fi for calls can consume more power.

Diagnosis of problems and frequent errors

Even after you set up correctly, users can run into problems, and the most common one is that the icon appears, but the calls don't go through or get broken, and this can indicate a profile conflict. APN or IMS-operator.

The second common case is that the VoLTE icon appears and disappears, which indicates an unstable signal from the base station. → SIM-maps and mobile networks → Preferred network type and select 4G (LTE), excluding 2G/3G, If the operator allows it.

If the problem persists, try removing and re-add the access point. APN. Sometimes the old settings interfere with the correct registration in the IMS-Reset the settings. APN to factory values via the mobile network menu.

• 🔄 Completely reset network settings (not data!).
• 🗑️ Remove old access points APN.
• 📲 Check for system updates in Settings → The phone.

⚠️ Note: When you reset your network settings, you will delete your stored Wi-Fi passwords and Bluetooth device settings.

In rare cases, the problem lies in the physical SIM-If it is cut from an old card or has damaged contacts, the Xiaomi modem may not read the necessary parameters for logging into the network. HD-- Replacement of voices. SIM-The card in the operator’s cabin often solves the problem.

💡

90% of VoLTE problems are solved by replacement SIM-cards to new or reset network settings to factory values.

The Impact of Function on Autonomy and Traffic

There's a myth that VoLTE consumes a lot of battery and Internet traffic. In fact, thanks to optimization of compression algorithms and the lack of constant switching between communication standards (2G/3G/4G), power consumption even decreases. A smartphone does not need to waste energy searching for another type of network during a conversation.

As for traffic, voice packets are high priority (QoS) and are not usually charged by the operator as Internet traffic. They count packet minutes. However, if you don't have unlimited minutes, keep an eye on the duration of conversations, because there are no minutes saved.

On two-device devices. SIM-cards (Dual) SIM) And it can be different. Often, VoLTE only works on one card at a time, usually the one that's chosen to transmit data. 2G/3G for incoming calls.

In conclusion, VoLTE technology is the standard of modern mobile communications. Xiaomi owners are strongly encouraged to configure this feature for a better experience, which will not only improve the quality of communication, but also prolong the battery life of your device in unstable coverage.