Modern Xiaomi smartphones provide users with a wide range of opportunities to improve the quality of voice communication, and one of the key technologies in this area is Voice over LTE. If you are a subscriber to the operator MegaFon, activation of this feature will allow you to make calls with crystal clear sound without interrupting high-speed Internet connection during a conversation. Many owners of Redmi and POCO devices face a situation where the HD or VoLTE icon does not appear automatically, which often causes confusion and search for solutions.
The problem of not being able to call over a 4G network can be covered in various factors: from the banal limitations of the tariff plan to the need to manually activate hidden engineering menus at the level of the MIUI or HyperOS operating system. Unlike simple settings in the call menu, deep activation requires care and accurate follow-up of instructions, since working with system parameters always involves certain risks. In this article, we will discuss all the stages, from checking the support of the service from the operator to complex manipulation of system configuration files.
It is worth noting that the menu interface may differ slightly depending on the firmware version and model of your gadget, whether it is a budget Redmi Note or flagship Xiaomi Mi. However, the logic of the system switches remains the same for the entire ecosystem of the Chinese manufacturer. We have prepared a step-by-step algorithm of actions that will help you enjoy high-quality communication of the new generation without unnecessary costs and trips to service centers.
What is VoLTE and why do MegaFon subscribers need it?
Voice over LTE technology is a voice traffic transmission exclusively through fourth-generation networks, bypassing outdated 2G and 3G standards. Previously, when an incoming call arrived, the smartphone forced to switch to lower frequencies, which led to a break in the Internet connection or a significant decrease in its speed. With the introduction of VoLTE, the device remains on the 4G network, ensuring simultaneous operation of voice and data without delay.
For MegaFon subscribers, this means not only a stable Internet during a conversation, but also a significant improvement in the quality of the sound itself. Voice is transmitted in high-definition format, which makes communication more natural and legible even in conditions of poor reception, where conventional networks could simply defuse a call. In addition, the connection is established almost instantly, removing the long horns waiting for a response from the interlocutor.
It is important to understand that this feature requires support from three components: the SIM card and the operator’s tariff, the base stations in your location and the smartphone itself. If at least one link in this chain is not configured correctly, the HD or VoLTE icon will not appear in the status bar. MegaFon is actively developing infrastructure, so coverage in large cities allows you to take advantage of the technology without restrictions.
⚠️ Note: Using VoLTE can consume a little more battery power in areas of uncertain reception, as the communication module operates in a constant high load mode to maintain channel quality.
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VoLTE allows you to talk on the phone and use fast Internet at the same time, without switching between network modes.
Checking the tariff and settings of the MegaFon SIM card
Before getting into the deep settings of Xiaomi smartphone, you need to make sure that the service is activated on the provider side.MegaFon operator often connects the VoLTE function automatically for modern tariffs, but in some cases, you need to manually confirm or replace the old SIM card with a new one that supports USIM. Without this step, any manipulation of the phone will be useless.
Check the status of the service in several ways, the fastest of which is the use of the service. USSD-If the service is not active, the system will offer to connect it for free, since for most tariff plans this option is included in the basic package without additional subscription fees. Also make sure that your area’s operator base stations support voice transmission through the network. 4G.
If a SIM card has been in use for several years, its chip may not support the necessary security and encryption protocols for LTE, in which case MegaFon recommends replacing the SIM card in the salon while maintaining its number and balance, a standard procedure that takes several minutes, but is critical to the operation of modern networks.
- 📱 Dial it. USSD-*117# command to check the status of the service on your number.
- 🌐 Go to the MegaFon app and check the Services section for active VoLTE option.
- 🔄 Make sure that the preferred network mode is selected in the phone settings in the Mobile Network section. 4G/LTE.
- 📍 Check the operator’s coverage map to make sure there are towers 4G in your current location.
Basic activation in the settings menu Xiaomi
Most of the modern models Xiaomi, Redmi and POCO With global firmware, you can set up through the standard menu without the need for codes. First, open your smartphone settings and find the section responsible for SIM-The path may be slightly different, but it's usually in the top menu or in the Connect and Sharing group».
Select a MegaFon SIM card if there are two in the device, and find a switch called "Use VoLTE" or "LTE Calls." In some versions of the MIUI shell, this item can be hidden inside the "Additional Settings" submenu, or only displayed if there is an active 4G network. Once the slider is turned on, the phone can restart the radio module, and the corresponding indicator should appear in the status bar.
If the switch is missing or inactive (grey), it means that the system does not see confirmation from the operator or the firmware does not contain the necessary profiles for your region, in which case standard methods will not be possible to do, and you will need to use more advanced activation methods through the engineering menu or third-party applications.
⚠️ Note: Do not try to turn on the "only" mode. 4G» in normal settings, if you are not sure of the coverage, otherwise you may lose the ability to receive incoming calls with a weak signal.
☑️ Checking basic settings
Activation through engineering menu and codes
When Xiaomi’s standard interface hides the options, an engineering menu comes to the rescue, accessible through a special set of commands: a hidden part of the system designed to test hardware, but also allowing you to control hidden modem functions. To log in, the universal code ##4636##, which should open the Testing menu, is used.
Once in the testing menu, select Phone Information, where you scroll down to find the VoLTE Provisioned or Turn on VoLTE Provisioned Flag switch. Activation of this flag forcefully tells the system that the operator supports the service, and allows the communication module to initiate calls over LTE. Once turned on, the phone may automatically restart or need to do so manually.
On some newer versions of Android and HyperOS shells, access to this menu through dialing may be blocked for security reasons. If the code does not work, you can use the Activity Launcher app or special utility for activating the engineering menu, which are available in the Google Play store.
##4636##
Alternative code for some regions:
##86583##What if the code doesn't work?
Comparison of Including Methods on Different Versions of MIUI
The variety of software models and versions creates a situation where the same method can work on one device and be useless on another. Xiaomi users often have to experiment with different approaches, as the company's policy regarding displaying communication settings is constantly changing. Understanding the differences between methods will help save time and avoid errors.
Below is a table comparing the main activation methods and their applicability in different situations, which will help you choose the most suitable option for your particular smartphone model and operating system version.
| Activation method | Difficulty | Efficiency | Risks. |
|---|---|---|---|
| Standard menu | Low. | High (official) | Absent. |
| Engineering code | Medium | Tall. | Minimum |
| Activator applications | Tall. | Medium | Possible bugs |
| Change of region | Low. | Low. | Change of settings |
It is worth noting that changing the region in the phone settings sometimes helps to unlock hidden features, as in some countries operators require mandatory certification to display the VoLTE icon. However, this method does not always work and can affect the operation of other system applications, such as the browser or voice assistant.
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If you’ve changed regions, be sure to check for NFC and other features, as they may be restricted by law in some regions.
Possible problems and ways to solve them
Even after successful activation, users may find themselves in a situation where the HD icon disappears or calls are disrupted, often due to unstable base station signal or temporary work on the operator’s network, in which case a simple flight mode switch for 10-15 seconds helps, which causes modem to re-register on the network and update the connection settings.
Another common problem is the conflict of two SIM cards when one of them does not support the SIM card. 4G ort-set 2G/3G. Xiaomi's system can block VoLTE on the main card if the second one is in standby mode on the old network.The solution is to set both SIM cards to mode 4G/LTE or temporarily disabling the second SIM for verification.
If nothing helps, it may be that the problem is that the system configuration files are damaged after the firmware update, which may require a complete reset of the network settings or even a flashing of the device to clean up the data. Before drastic measures, always try to delete the carrier profile and add it again through the settings menu.
- 🔁 Perform a reset of network settings: Settings → Connection and sharing → Resetting Wi-Fi, Cellular Networks and Bluetooth.
- 📡 Make sure you choose the right type of network: Preferably LTE, not 3G/2G.
- 🗑️ Remove and re-add the access point APN Operator MegaFon in the settings of the mobile network.
- 📞 Call the operator support team to check for locks on the equipment side.
⚠️ Note: Resetting network settings will remove saved Wi-Fi passwords and paired Bluetooth devices, so write down the required data in advance.
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The stability of VoLTE depends not only on the phone settings, but also on the signal quality and configuration of the second SIM card.