Owners of modern smartphones Xiaomi, Redmi and POCO often notice in the status bar next to the network indicator the mysterious inscription VoLTE. This icon does not appear at all users at once, which raises many questions about its purpose and necessity. In fact, this technology radically changes the quality of voice communication, transferring it to a new level of sound purity.
The acronym stands for Voice over LTE, which literally means Voice over LTE. Whereas earlier calls forced the phone to switch to older communication standards like 3G or 2G (EDGE), now all traffic, including voice, is transmitted over 4G high-speed protocol, which allows you to talk and use high-speed Internet simultaneously without losing connection quality.
For users of the MIUI ecosystem and the new HyperOS, this feature becomes a standard of quality. However, it depends not only on the capabilities of the smartphone itself, but also on the settings of the carrier. In this article, we will discuss in detail the technical aspects of the technology, how to force it to activate in hidden menus, and how to solve problems if the icon never appeared.
Technological foundations and advantages of VoLTE
Traditional cellular communications use circuit switching, which limits bandwidth during a conversation.Voice over technology LTE packs in IP-packets, just like messengers like WhatsApp or Telegram do, but with priority in the operator's network. This provides instantaneous connection — you hear the beeps almost immediately after you press the call button, without delay in the call. 5-10 Seconds of the Old Network.
The key advantage is that voice and data can work simultaneously, and in the past, if you were called while loading a page or navigating on Google Maps, your Internet connection would be interrupted or slowed down. With VoLTE enabled on Xiaomi devices, you can continue to download files, watch high-resolution videos or play online games while the conversation is ongoing. 4G/LTE.
The sound quality is also undergoing significant changes: voice is transmitted in a wider frequency range, making the interlocutor’s speech natural and legible, removing the effect of the “metal” voice. In addition, the technology consumes less battery power, since the communication module does not need to constantly switch between different frequencies and standards (3G/2G) during a call.
⚠️ Note: Using VoLTE can increase traffic consumption, although most modern operators charge such minutes as normal, not as Internet traffic.
Requirements for the function on Xiaomi smartphones
There are a few things that need to be done to successfully activate and operate the technology, and it's not enough to have a modern device from Xiaomi or Redmi, and the entire signal chain, from the base station to your handheld gadget, must support 4G LTE.
First of all, yours. SIM-The card must be registered on the network 4G. If you use the old one SIM-map 5-7 And it might have to be replaced in the cabin years ago, and the plan itself should be designed to support voice calls through the phone. LTE. Some operators require a separate connection to the service, although more often it is activated automatically.
The smartphone should be in the zone of confident reception of the signal 4G. If you are in a basement, a remote village or a building with thick walls, the phone will automatically switch to 3G, and the VoLTE icon will disappear.
☑️ Testing of VoLTE Readiness
How to enable VoLTE in standard MIUI settings
In most cases, modern MIUI and HyperOS shells automatically detect and enable support for the feature, but sometimes the setting may be hidden or disabled by the user earlier.
Open the Settings app and go to the section «SIM-maps and mobile networks. Choose SIM-If you want to activate a function (if there are two of them) find the "Use VoLTE" or "VolTE Calls" switch and activate it. If the switch is missing, this may mean that the operator has not provided a corresponding profile, or the function is hidden by firmware.
Once the status bar is turned on, a corresponding icon should appear next to the network indicator. On some Xiaomi models, the icon may not be displayed constantly, but only appear during a conversation, this is normal system behavior, indicating that the communication channel is installed correctly.
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If the VoLTE switch is not on the menu, try to remove it. SIM-You can wipe the contacts and paste them back, then reboot the device, and sometimes this helps the system re-read the operator profile.
Activation through the Engineering Menu and Hidden Commands
If the standard path is not working, you can use the hidden Android engineering menu, which is suitable for advanced users, because it requires caution, and changing the wrong parameters can lead to unstable operation of the communication module.
To enter the test menu, dial ##4636## in the caller. The Test menu will open. Select Phone Information. Find Set Preferred Network Type. Select the option that contains LTE and IMS, such as LTE Only or LTE/TD-SCDMA/CDMA EvDo/GSM/WCDMA.
adb shell settings put global volte_enabled 1This command, which is typed through the Android Debug Bridge (ADB), can force the VoLTE flag on the system if it is locked at the software level. However, this method does not work on all versions of Android and requires a connected computer. The simpler way is to use the 4G Switcher application or analogues, which require access rights through ADB to change system settings.
⚠️ Attention: Selection of regime «LTE Only" in the engineering menu can cause the phone to stop accepting incoming calls if the carrier does not support VoWiFi technology or if you leave the zone. 4G. Be careful.
Comparison of voice transmission technologies
To better understand the value of VoLTE, it's worth comparing it to other methods of voice transmission in cellular networks, and the differences are not only in the quality of sound, but also in the behavior of the network during conversation.
| Parameter | 2G/3G (CSFB) | VoLTE (4G) | VoWiFi |
|---|---|---|---|
| Sound quality | Low, narrow range | High (HD Voice) | High (depends on Wi-Fi) |
| Connection speed | 5-10 seconds | 1-2 seconds | 2-4 seconds |
| Internet during a call | Falls to 2G/3G or shuts down | It works at full speed 4G. | It works over Wi-Fi. |
| Battery consumption | High (network switching) | Low (one network) | Medium. |
As you can see from the table, the switch to Voice over LTE eliminates the main drawback of old networks – the Internet connection break. For owners of Xiaomi smartphones, which actively use navigation or messengers during a conversation, this is a critical feature.
VoWiFi (Voice over WiFi) is a logical extension of VoLTE, allowing calls to be made through Wi-Fi hotspots where there is no cellular signal. On Redmi and POCO devices, the two functions often work together to ensure continuity of communication.
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The main difference between VoLTE and 3G is the absence of a break in the Internet connection during a conversation and a much faster connection with a subscriber.
Possible problems and ways to solve them
Despite the technology's fine-tuning, users may face difficulties, and the most common problem is that the VoLTE icon doesn't appear, even though the phone and SIM card seem to support the function, often because the operator's configuration file is missing from the firmware of the smartphone.
In such cases, resetting the network settings helps. Go to Settings → Connection and Sharing → Reset Wi-Fi, mobile networks and Bluetooth. Click Reset. After rebooting, the phone will request configuration again from the operator, which may solve the problem.
Another reason could be an outdated version of the basic radio modulation. Check for system updates in the About Phone section → MIUI/HyperOS version. Xiaomi manufacturers regularly add support for new operators and regions in security updates.
What if the icon is missing after the update?
The impact of VoLTE on autonomy and safety
Many users mistakenly believe that running constantly in 4G mode quickly puts the battery down. In fact, VoLTE is optimized for minimal power consumption. Since the phone does not need to constantly jump between 2G/3G/4G standards in search of a network to call, the total power consumption even decreases.
Security is also important: voice traffic on LTE networks is more securely encrypted than on older GSM networks. However, it is worth remembering that the technology itself does not guarantee absolute anonymity, since the operator still sees the metadata of the call.
On Xiaomi devices with two SIM-Often, VoLTE works stably on only one SIM card (usually the one assigned to transfer data), while the second one can fallback on the SIM card. 3G. This is a limitation of the modem hardware in some budget models.