Modern Xiaomi smartphones support advanced voice technologies that allow you to transmit sound in high quality over the LTE network. For Tele2 subscribers, this feature, known as VoLTE (Voice over LTE), is a key advantage, as it provides instant connection and crystal clear sound without switching to 2G/3G. However, often users face a situation where the HD icon in the status bar does not appear, despite the availability of fourth-generation coverage.
The lack of activation can be caused by software restrictions of firmware, regional settings or a lack of permission from the carrier. Owners of Redmi and Poco devices often have to resort to hidden engineering menus to force the service to activate. It is important to understand that the setup process requires care, since interference with system parameters can affect the stability of the communication module.
In this article, we will discuss in detail all the ways to enjoy quality communication. We will look at regular activation methods, working with engineering menus through codes and specific commands. ADB You'll learn how to check your compatibility. SIM-What to do if after all the manipulations the desired result is not achieved.
What is VoLTE technology and why Tele2 subscribers need it
Voice over LTE technology is a 4G packet-based voice call, bypassing traditional 2G and 3G channels. For Tele2, which is actively developing its fourth-generation network, this is the main quality standard. Using LTE for calls allows you to simultaneously talk and use high-speed Internet without losing data speed.
The main advantage for the user is that the connection time is reduced: if in conventional networks the waiting for a response takes a few seconds, then with VoLTE, the beeps start almost instantly after pressing the call button. In addition, the sound quality becomes much higher, approaching stereo, which is especially important when talking in noisy places or through loud communication.
⚠️ Note: VoLTE usage consumes traffic, but most modern tariff plans Tele2 This traffic is not charged or goes into the account of the main package of minutes.
The function requires three conditions: support for the technology with a SIM card, the presence of LTE coverage in the area of the location and the appropriate setting of the smartphone. If one of the components is missing, the phone will automatically switch to standard communication protocols. In Xiaomi devices, the software implementation may vary depending on the version of MIUI or HyperOS.
Compatibility check and preparation of SIM-card
Before you go to the settings of the smartphone, you need to make sure that your SIM-map Tele2 Older SIM cards issued several years ago may not have a profile to work on networks. 4G In this case, you will need to change the card in the communication room or through the operator's application.
It is also important to check whether the VoLTE service is activated on the operator side. Tele2 It is often connected automatically when registering on the network. 4G, But in some cases, you need to activate manually, and you can do this through your personal account, your mobile app. Tele2" or USSD-Without confirmation from the network, the phone's settings won't work.
- 📱 Make sure that the network mode is enabled in the phone settings 4G/LTE.
- 📶 Check for a badge. 4G or LTE In the status bar without active calls.
- 🆔 Replace. SIM-New card if used for more than 5 years.
- 🔓 Make sure the slot is SIM-card 4G (It's usually the first slot).
After a physical check of the card and confirmation of the service by the operator, you can move to the software part. On Xiaomi smartphones, the settings can be hidden or blocked depending on the firmware region. Global versions of MIUI often have these settings open, while Chinese or Russian versions may require additional actions.
Activate VoLTE through the standard settings menu Xiaomi
The easiest and safest way to enable the feature is to check the standard Android settings menu. In the latest versions of the MIUI and HyperOS shell, developers have put this switch prominently if the carrier is identified correctly. First, open your device settings and go to the section responsible for SIM cards and mobile networks.
The selection menu SIM-Find a point related to the use of networks 4G. There must be a switch called "Use VoLTE" or "Calls on the Internet". LTE". If there is such a point, but it is inactive (shaded), it means that the phone sees the network, but does not receive confirmation from the operator or firmware blocks the function for your region.
Sometimes the switch is missing completely. In this case, change the region of the phone to the settings "Advanced" -> "Region." Installing the region "India" or "Singapore" often unlocks hidden menu items for local operators, which can work for Tele2, as these countries are leaders in the adoption of VoLTE.
☑️ Checking network settings
Using an engineering menu to force inclusion
If the standard methods don't work, you have to go to the Android engineering menu, which is a hidden part of the system, designed for testing equipment, and on Xiaomi smartphones, you can log in through a special code in the Phone app. Enter the combination ##4636##. If the menu opens, select Phone Information.
In the list that opens, find the option VoLTE Provisioned or "VolTE Flag Provided." Set the switch to active position. This action tells the modem that the service is paid for and authorized, causing the phone to send appropriate requests to the Tele2 network. Once the switch is turned on, the HD icon should appear in the status bar.
##4636##Note that newer versions of Android may have the menu blocked by the manufacturer for security reasons, which means that the code simply won’t work or the standard set menu will open. Alternative methods, including using third-party apps or ADB commands, exist for these cases, but they require a connection to a computer.
⚠️ Warning: Do not change other options in the engineering menu unless you know exactly what they are responsible for.Resetting the settings of the radio interface can lead to temporary loss of communication.
Setup through hidden codes and applications
For devices where the standard engineering menu is not available, there are alternative codes specific to Qualcomm or MediaTek chipsets used by Xiaomi. For example, code ##86583## can force the display of the VoLTE switch in the settings. Enter it in the dialer, and you should see the message "VoLTE carrier check was disabled", which means unlocking the function.
Another effective method is using the 4G LTE Switcher app or Google Play analogues, which allow you to manage network priorities and force the IMS protocols necessary for VoLTE to work. Once you install the application, grant it the necessary permissions through ADB or root rights, if any.
| Activation method | Difficulty | Efficiency | Risks. |
|---|---|---|---|
| Standard menu | Low. | High (if available) | Absent. |
| Engineering code (#4636##) | Medium | Tall. | Minimum |
| Unlock code (#86583##) | Low. | Medium | Absent. |
| Switch applications | Tall. | Depends on the model. | Average. |
Some users have noted that after installing MIUI updates, the function stops working, requiring re-activation through the engineering menu, which is a normal behavior associated with updating the basic modem files.
What if the code doesn't work?
Solving and eliminating connection errors
A common problem is when the icon HD It appears, but calls are still dropped or transferred to 3G. This may indicate a conflict of settings. APN or profile problems IMS. Try resetting the access point settings APN To do this, go to the mobile network settings, select yours. SIM-map Tele2 and press "Reset." APN".
Another reason could be dual-sim mode. Some Xiaomi models don't support VoLTE on two SIM cards at the same time. Try to turn off the second SIM card temporarily and check the function on the main one. If the problem disappears, then the limitation is on the hardware part of the modem of your device.
- 🔄 Completely reset your network settings (not data!) to update your network registration Tele2.
- 📵 Turn off power saving mode, which may limit the operation of the communication module.
- 🏗️ Check for system updates in the About Phone section".
- 📲 Make sure the phone app is updated to the latest version.
If nothing works, it’s possible that your phone is simply not certified to work with VoLTE on Tele2 networks at the software level, in which case it helps to flash the device to the global version of MIUI or use patches, but this already requires deep knowledge and carries the risk of losing warranty.
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Before resetting your network settings, write down the current APN settings manually or take a screenshot, which will help you quickly restore Internet access if the automatic settings do not apply.
Impact of MIUI version and regional restrictions
The operating system version plays a critical role in the availability of communication functions. Chinese versions of firmware (China ROM) often have a wider set of settings for engineers, but may not have pre-installed profiles for Russian operators. European (EEA) and Global (Global) versions, by contrast, are strictly certified, but may have a reduced functionality to suit the standards of a particular region.
Regional restrictions also affect frequency bands. Although Tele2 operates in standard bands, software locking can prevent registration in VoLTE mode. Changing the region in the phone's settings is a simple trick that often bypasses software locks, making the system think the device is in a country where VoLTE is a mandatory standard.
⚠️ Note: Changes in region may affect some Xiaomi system applications and services, such as Mi Video or Mi Music.Be prepared for ads or changes to the set of preinstalled programs.
Users who travel frequently should know that VoLTE settings are tied to a specific operator. SIM-cards to another operator, the settings can automatically change. Tele2 It is important that the VoLTE icon is on fire in the status bar or HD, This ensures the use of high-quality voice codecs.
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Changing the region to India or Singapore will unlock hidden VoLTE switches for Russian operators on Xiaomi smartphones in 80% of cases.