Modern smartphones like the Redmi 9 Pro offer a wide range of communication capabilities, among which VoLTE technology occupies a special place. It allows voice calls over a fourth generation network, providing high sound quality and the ability to use the Internet simultaneously. However, this feature is not stable in all regions, and sometimes users are faced with a situation where mobile Internet is lost during a conversation or the quality of communication becomes unsatisfactory.
Xiaomi device owners often look for ways to deactivate this option to switch to standard 3G or 2G networks for more reliable voice communication. The shutdown process can vary depending on the MIUI firmware version and regional settings of the device. In this article, we will discuss all available methods in detail, from simple menu switches to more complex engineering settings.
Understanding how to manage network protocols is an important part of smart smartphone use. Disabling VoLTE on Redmi 9 Pro often solves the problem of “disappearance” of the 4G network during a call, causing the phone to return to LTE mode immediately after the conversation is over, rather than keeping the connection unstable. Let’s look at the technical aspects and practical steps to solve this problem.
Understanding VoLTE Technology and Its Impact on Redmi 9 Pro
Voice over LTE technology is a voice-over-driven approach that is directly transmitted over 4G packet networks, bypassing the switch to older communication standards. For the Redmi 9 Pro, which is equipped with Qualcomm’s powerful modem, support for this standard is native, but its implementation depends on the operator and operator settings. When the function is active, the phone does not fall into 3G whenever a call is made or out.
However, there are situations where VoLTE is not working properly, which may be due to poor 4G coverage in a particular location or incompatibility of operator settings with the current version of the software, in which cases users experience interruptions in sound or inability to reach the phone, making disabling the function the only reasonable way out.
It is worth noting that on global versions of MIUI firmware, the switch is often hidden or, conversely, rigidly tied to the SIM card. Local versions, for example, for India or Russia, can have their own features of displaying this parameter in the menu.
Xiaomi engineers are constantly updating carrier databases, but sometimes the automatic configuration leads to conflicts.If your phone is constantly trying to escape into LTE during a call and loses signal, manual management of network preferences becomes a necessary skill to ensure the stability of communication.
Standard method of disconnection through settings SIM-map
The easiest and safest way to manage voice calls LTE It's in the standard settings menu of the phone. First, you need to open the Settings app and go to the section. SIM-Maps and mobile networks. This shows all active SIM cards installed in your Redmi 9 Pro.
Select the SIM card that needs to change settings. In the menu that opens, find the 4G option. Depending on the shell version, it can be called "Use VoLTE", "LTE Calls" or have the appropriate icon next to the operator name. The switch is usually active by default.
☑️ Pre-switch check
Once the switch is deactivated, the phone will automatically reconfigure the connection, and you may notice that the HD or VolTE icon has disappeared from the status bar, and now when making calls, the device will force the switch to third-generation networks, which will provide a more stable, if less high-quality connection.
⚠️ Warning: After disabling the function, mobile Internet speed during a conversation may decrease to standards 3G (H+), The phone will no longer use the channels. 4G voice-transmitting.
If the switch is missing or inactive (shaded), it means that the carrier or firmware itself is blocking manual control, in which case you need to resort to alternative methods described below, which allow you to bypass software constraints.
Using an Engineering Menu to Manage a Network
When standard settings fail to deliver the desired result, the Android Engineering Menu comes to the rescue, a hidden part of the system designed for hardware testing, but also accessible to ordinary users. Redmi 9 Pro can be accessed through a special application or code, but newer versions of MIUI often block codes.
Access to advanced network settings often requires the installation of a special application, for example, 4G Switcher or use code ##4636## in the Phone app. If the code doesn't work, you can try entering it through the Touch Key app or use it. ADB-commands to run the activity of the test menu.
In the menu that opens, select Phone Information. Here you will see a lot of options, including Set Preferred Network Type. Changing this option allows you to force the modem to switch, for example, selecting 3G only mode (WCDMA only) will completely eliminate the use of LTE, and therefore VoLTE.
Risks of using the engineering menu
Be careful when changing the settings in this section, and if you misconfigure it, it can cause the phone to stop seeing the network at all, which can be done by simply restarting the device or resetting the network to factory values.
Application ADB-commands for hidden settings
For advanced users who are not afraid to work with the command line, there is a method to disable VoLTE through USB debugging. This method requires connecting Redmi 9 Pro to a computer and having an installed Android Debug Bridge package.
First, you need to activate the developer mode. To do this, seven times click on the MIUI version in the About Phone section. Then turn on USB Debugging in the developer menu. Once you connect to the PC and log in on the smartphone screen, you can type commands.
adb shell settings put global volte_enabled 0This team is trying to change the global system parameter responsible for VoLTE support. However, on modern Xiaomi shells, direct change of settings through settings put is often blocked by access rights.
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Before entering any commands through ADB, back up your important data. Although the risk is minimal, interfering with system settings always requires caution.
If the direct command doesn’t work, you can try to force the network type to be installed via ADB using the adb shell service call phone 67 i32 2 (the parameters can vary depending on the modem model).
Comparison of network modes on Xiaomi
Understanding the differences between network modes helps you choose the optimal configuration for your conditions. Below is a table comparing the main features of the Redmi 9 Pro in different modes.
| Parameter | VoLTE (4G) | 3G (WCDMA) | 2G (GSM) |
|---|---|---|---|
| Sound quality | High (HD) | Average. | Low. |
| Internet speed when calling | High (4G) | Medium/Low | Very low (EDGE) |
| Stability of connection | Depends on the coverage | Tall. | Maximum |
| Battery consumption | Medium. | High (network search) | Low. |
As you can see from the table, turning off VoLTE puts the phone in a mode where the stability of voice communication, rather than data speed, is a priority. In areas of uncertain 4G reception, this can significantly improve the situation with the dosage.
If you want fast internet while you're talking and you're in a city with good coverage, VoLTE is preferable. In rural areas or when traveling, you'd better rely on proven 3G networks.
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Optimal network mode is a compromise between voice quality and Internet speed, which is selected experimentally for each location.
Solution: What to do if settings are reset
Users often find that after the Redmi 9 Pro reboot, the network settings return to their original settings, and VoLTE is activated again. This is the behavior of a system that tries to optimize the connection based on the operator's data. To combat this, you can use automated applications like Tasker, which will change the settings when you start the system.
Also, the reason for the reset may be a firmware update, Xiaomi periodically releases patches that return functionality that has been changed by the user, in which case only repeating the procedure of disconnecting or waiting for an update of the operator database helps.
Sometimes the problem lies in the very SIM-If the card is too old and does not support modern standards of registration in the network, the phone can behave unpredictable, replacing the SIM card with a new one in the operator’s cabin often solves the problem of chaotic switching modes.
Physical factors are also important: A damaged SIM card tray or contact oxidation can cause false signals to a system that changes network settings in response, and checking the physical condition of the slot is an important diagnostic step.
The Impact of Regional Firmware on Function Availability
It is important to consider that the functionality of Redmi 9 Pro is highly dependent on the regional version of the firmware. Global versions (Global ROM) usually have stricter restrictions imposed by Google and local regulators, while the Chinese versions (CN ROM) may provide more technical features, but lack some Google services by default.
On Indian firmware devices, for example, VoLTE is often a requirement of local operators, and it is impossible to disable it using standard methods, in which cases users have to resort to flashing the device to a global version or using modified versions of the software.
⚠️ Warning: Flashing the phone to another regional version may lead to loss of warranty and disruption of banking applications (NFC, Do this only if you are fully aware of the risks.
The firmware version is checked under the "About Phone" section. If you see the designation MI, it's Chinese, EU is European, RU is Russian, IN is Indian, and knowing this acronym will help you find the exact instructions for your particular case on the Internet.