Owners of modern smartphones Xiaomi, Redmi and Poco often notice in the status bar icon “VoLTE” or “HD”, but not everyone understands the real benefits of this technology. Voice over LTE is a standard for voice calls through fourth-generation networks, which radically changes the quality of communication compared to the usual 2G and 3G networks. If you want your phone to work faster and better, you can not ignore this parameter.
The technology allows voice to be transmitted as a data stream, bypassing switching to outdated frequencies, which provides instant connection and crystal clear sound. Many users do not even suspect that their device supports this feature by default, but it is hidden or not activated by the provider. In this article, we will discuss in detail how to make your gadget work at full power.
As you understand what VoLTE means on Xiomi's phone, it's important to understand that it's not just a picture enhancer, it's a fundamental change in the architecture of the call. In the past, when a call comes, the phone would force it to 3G or 2G, breaking the high-speed Internet connection, and now voice is transmitted over 4G, leaving the Internet channel free and stable.
The principle of Voice over LTE technology
Traditional cellular communication uses circuit switching, where a separate frequency is allocated for a conversation. VoLTE uses packet switching, similar to messengers, but with real-time priority. This means that the voice is broken into data packets and transmitted over the LTE network, providing a delay of no more than 0.1 seconds versus 1.5-2 seconds in older networks.
The main advantage is that voice and the Internet work simultaneously: you can talk and download heavy files, watch videos or play online games without dropping speed to EDGE. For tariff owners with high traffic volume, this is a critical aspect, since the quality of communication ceases to depend on the loading of the tower.
⚠️ Attention: VoLTE communication quality depends on network coverage 4G. If you are in a zone where you are only caught 3G, The phone will automatically switch to a standard voice call, and the icon will be HD lost.
Technically, MIUI (the Xiaomi shell) fully supports this standard, but implementation depends on regional firmware. Global versions often have hidden settings that require activation via an engineering menu or special codes. Chinese versions, by contrast, may have this feature enabled by default for local operators.
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VoLTE transmits voice as Internet traffic, ensuring the simultaneous operation of data and without switching network modes.
The main advantages of activation HD-call-up
The switch to High Definition Voice technology has a dramatic boost in communication, and the sound becomes volumetric, the noise disappears, and the compression effect of old networks, and the interviewer hears you as if you were in one room, not the other side of town.
Connection speed is another key factor: dialing and dialing start almost instantly after you press the call button, you no longer have to wait a few seconds for the network to find the subscriber and switch channels, especially when calling emergency services or in a bad signal.
List of benefits of using VoLTE on Xiaomi devices:
- 🚀 Instant connection with the subscriber without delay.
- 🎙️ High quality sound with extended frequency range.
- 📶 Simultaneous work 4G Internet and voice.
- 🔋 Reducing the power consumption of the communication module due to the absence of constant reconnections between the two 2G/3G/4G.
In addition, the technology allows for additional services, such as high-quality video calls directly through the phone book, without the use of third-party applications. LTE), This will be a logical continuation of the standard.
Compatibility of operators and tariff plans
Having support for technology in a smartphone is only half of the success, and the second, equally important component is the support from your carrier and the availability of the corresponding option in the tariff. In Russia and CIS countries, all major providers have already implemented this feature, but conditions may vary.
The service is usually free, but requires a connection, and in some cases it activates automatically when replaced. SIM-new card with support 4G. Older SIM cards issued more 5-7 years ago, you may not have the necessary profiles to work in the network LTE voice-over.
Table of support for VoLTE by the main operators (relevant for the Russian Federation):
| Operator. | Support for VoLTE | Activation conditions | Tariffing |
|---|---|---|---|
| MTS | Complete. | Automatically or through the application | Free (minutes at the fare) |
| Megaphone | Complete. | Setting up in the Personal Cabinet | Free (minutes at the fare) |
| Beeline | Complete. | USSD-team | Free (minutes at the fare) |
| Tele2 | Complete. | Automatically for 4G tariffs | Free (minutes at the fare) |
It is important to note that roaming using Voice over LTE may be unavailable or charged separately. Before traveling abroad, it is recommended to check with the operator the possibility of committing HD-It is also worth remembering that in some regions the coverage of the 4G It can be unstable, which will lead to frequent switching to 3G.
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If you have changed the operator, but kept the old one SIM-card, contact the communication salon to replace the chip - this often solves problems with the display of the icon HD.
How to enable VoLTE in Xiaomi settings
Activation of the function on Xiaomi smartphones usually occurs automatically if the SIM card and the operator support the technology. However, if the icon does not appear, you need to check the settings manually. MIUI or hyperos.
To start, open the standard Phone app or go to the general settings of the device. You need to find the mobile network section. Often users look for the switch in the About Phone section, but this is a mistake - the control is deeper in the system.
Step-by-step activation instructions:
- 📱 Go to the settings of your smartphone.
- 📡 Select a point. SIM-maps and mobile networks.
- 🔘 Click on the name of your operator (SIM 1 SIM 2).
- ✅ Find the Use VoLTE switch and activate it.
If the switch is missing or inactive (grey), it means that the system has not determined support from the side. SIM-If you want to reboot the device, or re-extract and repaint the SIM card, sometimes resetting the network settings helps.
☑️ Pre-insertion check
Hidden settings and engineering menu
In some cases, especially on Xiaomi’s global firmware, the standard interface hides the ability to enable Voice over LTE for certain regions. This is where the engineering menu comes in to help access hidden modem features. Beware: changing unknown parameters can lead to unstable communication.
To log into the engineering menu, a special code is used in the Phone app. Dial ##4636##. If the menu does not open, your shell version may block this access and you will need to install a third-party application, such as Activity Launcher or specialized utilities for setting up Xiaomi.
After entering the menu:
- Select Phone Information (Phone Information).
- Find the Set Preferred Network Type section.
- Make sure that you select a mode that contains LTE (e.g. LTE/TD-SCDMA/GSM).
- Below, find the VoLTE Provisioned or Enable VoLTE switch and turn it on.
⚠️ Warning: Do not change the settings in the Radio Power section or other system flags in the engineering menu without knowing their exact purpose.
After making the changes, be sure to restart your smartphone. If after rebooting the HD or VoLTE icon appeared and is stable, then the procedure was successful. If the phone began to lose network or constantly switch between modes, return the settings to the original state.
What if the code doesn't work?
Frequent problems and ways to solve them
Despite the technology’s fine-tuning, Xiaomi users may face a number of typical problems: most commonly, a VoLTE icon is on fire, but calls are disrupted or sound quality remains low, which may indicate a base station overload or a software conflict.
Another common problem is that the icon disappears after a system update, and newer versions of MIUI can reset user network settings or change the list of supported carriers, in which case re-activation through the engineering menu or resetting APN settings helps.
The main symptoms of malfunction:
- 📉 Badge 4G disappears during conversation.
- 🔇 The interviewee complains of interruptions or echoes.
- 🔄 The phone is constantly switching between 3G and 4G.
- ❌ Inability to make an outgoing call when the Internet is turned on.
To diagnose the problem, try installing another carrier's SIM card, and if VoLTE works with another SIM card, it means that the problem is on the side of your current provider or the SIM card itself. If the problem persists, there is a possible software failure in the firmware of the smartphone.
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If the VoLTE icon disappeared after the firmware update, reset the network settings (Settings → Connection and Sharing → Reset Wi-Fi, mobile network and Bluetooth).