Owners of modern smartphones Xiaomi, Redmi and Poco often notice the appearance of a small but noticeable icon VoLTE at the top of the screen, next to the signal level indicator. For many users, this visual change becomes a cause for concern or, conversely, a matter of pride if the function appeared on its own. Understanding what exactly lies behind this acronym helps not only to get rid of unnecessary anxiety, but also significantly improve the quality of voice communication.
Essentially, this technology represents an evolution of mobile standards that allows voice to be transmitted as a data stream over a 4G LTE network, bypassing the old 2G and 3G standards. In the context of the Miui and HyperOS ecosystem, activating this option often requires not only support from the operator, but also the correct configuration of the device itself. Ignoring this parameter can lead to the phone resetting the network to 3G during a conversation, interrupting the Internet connection.
In this article, we will discuss in detail the technical aspects of the fourth generation voice communication, how to force the activation of hidden menus and methods for solving common problems. You will learn why the icon can burn gray and what hidden opportunities this mode opens for you in Xiaomi smartphones.
Technological essence of VoLTE and difference from conventional calls
Traditional cellular communication has used circuit switching for decades, where each conversation is allocated a separate frequency band. LTE It changes the way you look, by packing your voice into IP-packets, just like when you send messages in messengers or stream music, it allows Xiaomi to stay online. 4G Even at the time of an incoming or outgoing call, providing an instant connection.
The main advantage is that the connection speed and the simultaneous operation of voice and data. If earlier when calling the Internet connection fell to EDGE or 3G, which made it impossible to navigate or watch video, now the channel bandwidth remains maximum, while the sound quality increases to the level of HD Voice, becoming cleaner and more natural thanks to the extended frequency range.
However, it requires three components to work correctly: carrier support for the standard, availability of the appropriate SIM card, and phone hardware. Xiaomi smartphones often have hidden engineering menus that allow this feature to be activated even where it is not officially announced, making them popular among tech-savvy users.
Impact on the battery
How to activate the function through the standard settings menu
The first and most logical step for a Redmi or Poco owner is to check the standard interface. Manufacturers embed the switch in the shell, but its location can vary depending on the Android version and regional firmware.
You need to go to the settings menu and find the SIM card item, and it's important to make sure that the SIM card you want is the type of network you prefer 4G. Without that, the phone won't just try to log in to the fourth generation network for voice calls.
Next, you should find the "Use VoLTE" or "Calls over LTE" switch. In some versions of the Miui, this item can be hidden inside the "Additional Settings" or "Extended Settings" menu. If the icon does not appear in the curtain after the slider is turned on, try restarting the device or moving the SIM card to another slot.
☑️ The VoLTE Incorporation Algorithm
It is worth noting that on global firmware versions, this switch is often present by default if the carrier is added to the Xiaomi whitelist. On Chinese versions (CN ROM) or custom assemblies, the activation path may differ and require the use of engineering code.
Hidden codes and an engineering menu for activation
If a standard switch is not available, the hidden capabilities of Android come to the rescue, available through a set of special character combinations, which is the most effective method for devices where the operator is not listed as officially supported, but there is a technical possibility.
To enter the engineering menu, you need to open the Phone app and dial ##86583#. In most cases, after entering the last digit, the screen will blink and a notification will appear, "VoLTE check carrier was disabled" or "enabled", which means that you have hidden or opened the operator's check.
Once you have completed this command, go back to the SIM card settings. If everything goes well, a previously hidden VoLTE switch should appear there. Alternative code for some Xiaomi models is ##4636##, which opens an extended test menu.
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If code 86583 doesn’t work, try entering code 86863 (without stars and bars) – this is an alternative command for some versions of MIUI 12 and 13.
In the 4636 test menu, you select Phone Information and find the drop-down list “Install preferred network type.” Here you can manually select LTE only or LTE/TD-SCDMA mode, which will force the phone to only work in 4G mode, where VoLTE is available.
| Team team. | Function | The result |
|---|---|---|
| ##86583## | Control of the operator | Turns on/off the switch concealment |
| ##4636## | Test menu | Opens access to the choice of network type |
| ##86863## | Alternative verification | Duplicates the first code function on new MIUIs |
| *#06# | Information on IMEI | Checking the registration of the device on the network |
Why does the icon burn gray or disappear?
The situation when the icon VoLTE is displayed in gray or periodically disappears, is a common problem in the network. 4G. The gray color of the indicator usually signals that the technology is activated in the phone settings, but there is currently no registration in the phone. IMS-operator.
There are several reasons why this could happen. First, you could have stepped out of the safe zone. 4G, and the phone temporarily switched to 3G Second, the problem may lie in the tariff plan: some operators require the connection of an additional service or switch to a new tariff for work. HD-voice.
⚠️ Note: If the icon is constantly gray, check if the main minutes of the packet are over.In some cases, the operator blocks VoLTE at zero balance, even if the packet data is running.
Also, consider base station congestion, because during peak hours, when network load is at its highest, normal traffic is given priority, and resources for voice packets may not be allocated temporarily, in which case the icon may appear or disappear.
Compatibility of operators and SIM cards
Not all SIM cards are equally useful for working with new standards. Old SIM cards issued more than 5-7 years ago may not support the necessary authentication protocols on the IMS network. If your Xiaomi phone is new and the SIM card is old, it is recommended to replace it in the carrier cabin.
The largest operators (the “big four”) in most regions have already deployed VoLTE networks, but coverage may differ: in rural areas, for example, 4G infrastructure may be focused only on data, and voice is still serviced via 3G. In large cities, there are usually no problems.
It is important to check the settings of the access point APN. Sometimes automatic settings do not prescribe the desired profile for the IMS. Manually adding the ims parameter to the type APN, You can force the protocol you want to activate. → SIM-map → Access points (APN).
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Replacing the old SIM card with a new one with USIM support is the easiest solution if the phone and carrier support VoLTE, but the icon does not appear.
Frequent problems and methods of their elimination
Users often find that after updating the Miui firmware, the network settings are lost. If the icon disappeared after the update, the first thing you do is reset the network settings, which will not delete your personal data, but return the network settings to factory values.
Another common problem is the conflict between two SIM cards, where if both SIM cards are in 4G mode, the phone may not be properly allocated resources, try temporarily disabling the second SIM card and checking VoLTE on the main one, and changing the priority of the SIM card for the mobile Internet also helps.
- 📱 Make sure that the settings are selected mode «4G preferably, rather than «3G/2G».
- 🔄 Reset network settings through the Connections and Sharing menu».
- 📡 Check for updates to the system and profile of the operator.
- 🗑️ Remove old, unused access points APN, leaving only relevant.
In rare cases, the problem lies in the communication module of the smartphone, especially in devices recovered after repair. If nothing helps, you should contact the service center for the diagnosis of the antenna module.
The impact of technology on communication quality and battery
Many users fear that running 4G will land the battery faster. However, the modern modems in the Snapdragon and MediaTek processors used by Xiaomi are optimized for LTE. Moreover, the lack of constant jumps between 3G and 4G during a call can even save charge.
VoLTE sound quality is subjectively assessed as significantly higher, the effect of the “robotic” voice disappears, background noise disappears, and the connection is established in 1-2 seconds instead of the usual 5-7. For headphones and headsets owners, this is a critical parameter.
⚠️ Note: VoLTE is transmitted via an Internet channel, and make sure you do not run out of traffic, although most operators do not charge this traffic separately.
So activating this feature is one of the easiest ways to upgrade the smartphone experience without buying a new device.It's a communication standard that's becoming the norm, and ignoring its capabilities makes no sense.