Modern smartphones Xiaomi have a wide range of functionality, often hidden deep within system settings. One of the most useful, but not always obvious, features is the technology VoWiFi, allowing voice calls to be made over a wireless network. This solution is ideal for areas with poor cellular coverage, where regular calls are dropped or not received at all.
Many users aren't even aware their device supports this feature, or they're faced with a missing switch in the standard menu. Enabling this option can dramatically change the connection quality in an office, basement, or country house. Below, we'll detail how to activate this feature, the hidden methods available, and what to do if the desired option isn't displayed.
What is VoWiFi technology and why is it needed?
Technology VoWiFi Voice over Wi-Fi (Voice over Wi-Fi) is a standard for transmitting voice traffic over an internet protocol. Unlike popular messaging apps, this method uses standard phone numbers and is integrated into the smartphone's dialer. To the other person, your call appears as a regular phone call, not an app call.
The main advantage is connection stability in radio-quiet zones. If the building has thick walls that shield the base station's signal, but there's a working router, the connection quality will be excellent. Xiaomi is actively implementing support for this function in its firmware MIUI And HyperOS.
⚠️ Please note: This feature requires support from your mobile operator. Without activation, your phone settings will be useless.
Using this mode also helps conserve battery life, as the smartphone doesn't need to constantly strengthen its signal while searching for a cell tower. This is especially important when traveling on the subway or in metal-framed buildings.
Checking operator and tariff compatibility
Before accessing your smartphone's settings, make sure your plan supports voice over internet. The "big four" carriers have long since implemented this feature, but it often requires separate activation in your account.
Service terms and conditions may vary. In some cases, it is activated automatically upon the first request, while in others, a USSD command is required. It's also important that the SIM card be up-to-date, as older models may not support the required encryption protocols.
Check the current terms and conditions on the provider's official website or in the app. Sometimes the service may be free, but require identity verification through Gosuslugi or passport information.
Standard activation method via Android settings
In most cases, this feature is enabled through the standard settings menu. The interface may vary slightly depending on the shell version. MIUI, but the logic remains the same.
You need to go to the SIM cards and mobile networks settings section. This is where the required toggle switch is located. If you use two SIM cards, the settings apply individually to each slot.
☑️ Enablement algorithm
After powering on, a special icon resembling a telephone handset with a Wi-Fi symbol may appear in the status bar next to the signal strength. This indicates successful registration with the operator's network via the internet.
If the switch is found and enabled, but the icon doesn't appear, try restarting your device or toggling Airplane Mode on and off. This will help your phone re-register with the network.
Hidden settings via the engineering menu
In situations where the standard switch is not available in the menu, you can use the engineering menu AndroidThis method allows you to access hidden modem functions. Be careful, as changing unknown parameters may disrupt your connection.
To access the diagnostics menu, you need to enter a special code in the "Phone" app. After entering the code, the testing interface will open, where we'll find the section responsible for phone settings.
##4636##In the menu that opens, select "Phone Information." Scroll down to the section VoWiFi or ProvisionedHere you can manually activate support for this feature.
⚠️ Caution: Do not change values in other tabs of the engineering menu unless you are sure of their purpose. Doing so may result in network loss.
After changing the settings, be sure to restart your smartphone. If the code doesn't work or the menu doesn't open, the manufacturer may have blocked access to these features in your region.
What to do if the code doesn't work?
Some carriers or firmware versions block access to the engineering menu via standard dialing. In this case, you can try using third-party apps to access the test menu or an ADB command.
Activating the function via ADB commands
The most reliable, but technically challenging, method is to use USB debugging and a computer. ADB (Android Debug Bridge) allows you to make changes to system databases that are not accessible through the interface.
First, you need to enable developer mode on your smartphone. To do this, quickly tap the build number seven times in the "About phone" section. After that, the "Developer options" menu will appear, where you need to enable USB debugging.
Connect your phone to your computer, install the drivers and ADB tools. Run the command to check the current status of the feature. If it's disabled at the software level, the command below will enable it.
adb shell settings put global carrier_vowifi_enabled 1You may also need to change the setting that controls the option's visibility in the menu. This will return the missing toggle switch to its default settings.
adb shell settings put global carrier_default_wfc_ims_enabled 1After executing the commands, the phone needs to be rebooted. This method is universal for most devices based on Android, including Xiaomi, Redmi And Poco.
Comparison of VoWiFi Enabling Methods
Different activation methods have their pros and cons. The choice depends on your technical expertise and the specific smartphone model. Below is a table to help you choose the best option.
| Method | Complexity | Risks | Efficiency |
|---|---|---|---|
| Android settings | Low | None | High (if available) |
| Engineering menu | Average | Average | High |
| ADB commands | High | Low (if done carefully) | Maximum |
| Operator applications | Low | None | Depends on the operator |
The default settings are the safest option, but they don't always work. The engineering menu requires caution, but doesn't require a PC connection. ADB provides full control, but requires a computer and basic command line skills.
Choose a method that suits your comfort level with technology. If you're unsure, it's best to stick with the default settings or contact a mobile phone store.
Possible problems and solutions
Even after proper setup, difficulties can still arise. Users often encounter a situation where the icon appears, but calls fail. This may be due to a network protocol conflict or router settings.
Make sure the ports required for SIP protocols aren't blocked on your router. The problem could also be caused by your antivirus or firewall software, which is viewing voice traffic as suspicious.
⚠️ Note: Operator interfaces and firmware are updated regularly. If the menu items described are missing, check the manufacturer's or operator's official website for the latest instructions.
Try resetting your network settings to factory defaults. This will delete saved Wi-Fi passwords and Bluetooth settings, but it often resolves VoWiFi network registration issues.
If all else fails, it's possible your phone model isn't certified for VoWiFi in your region. In that case, you'll have to rely on messaging apps or find a location with a better cellular signal.
Does using VoWiFi affect my billing?
Typically, minutes spent making Wi-Fi calls are charged the same as regular minutes in your plan. However, if you're abroad, the terms may differ. Check with your provider before traveling.
Does this feature use a lot of internet traffic?
Voice traffic consumes very little data. One minute of conversation takes up approximately 0.5–1 MB of data. By comparison, a minute of HD video can consume 10–15 MB.
Is it possible to make calls via Wi-Fi if the SIM card is not active?
No, to register for a VoWiFi network, the SIM card must be active and have at least minimal visibility into the operator's network, or the phone must have network access via an eSIM. The technology doesn't work completely without a SIM card.
Why does the VoWiFi icon disappear when there is an incoming call?
This may indicate that your phone is switching to a cellular network while connected due to unstable Wi-Fi or network priority settings. Check that your network priority settings are set to "Wi-Fi Only" or "Wi-Fi Preferred."