Modern smartphones Xiaomi They're equipped with powerful communication modules, but even they can't always provide a stable signal in remote areas of the home or office. It often happens that the network indicator shows a single bar or disappears completely, making it impossible to make important calls. In such situations, technology comes to the rescue. Voice over Wi-Fi, which allows voice calls to be transmitted via an Internet channel.
This feature is not a new invention, but on devices MIUI And HyperOS Activating it may have its own nuances, depending on the firmware version and region. Users often confuse regular calls via messengers with the carrier's native feature, which is integrated into the standard dialer. We'll explain how to properly set up this service so your phone makes calls like a regular mobile phone, but using a wireless network.
Before proceeding with the settings, you need to ensure that your tariff plan and mobile operator support this service. Without confirmation from your provider, any changes to your smartphone's menu will be useless. Below, we'll cover the technical requirements and a step-by-step procedure.
Technical requirements and equipment preparation
To successfully activate the function VoWiFi (Voice over Wi-Fi) your device must meet a number of criteria. First and foremost, this refers to the smartphone's hardware and software supporting the technology. Most modern models Xiaomi, Redmi And Poco, released in the last 3-4 years, provide the necessary functionality.
⚠️ Attention: The settings menu interface may differ depending on the MIUI or HyperOS version. If you can't find an option, it may be hidden in the engineering menu or missing from your regional firmware.
The second critical component is the router. It must correctly handle SIP protocols and not block the ports required for voice traffic. This is rarely a problem in home networks, but it can be challenging in corporate networks with strict firewalls.
It's also worth checking whether the service is enabled with your mobile operator. Some providers activate it automatically, while others require sending a USSD request or activating it through your account. Without this feature, your phone may display the "Wi-Fi Calling" icon, but calls will be dropped or connected through the cellular network if available.
- 📱 Xiaomi smartphone with 4G/LTE support and the latest software version.
- 📡 Stable wireless connection with good speed.
- 📞 An active SIM card from an operator that supports VoWiFi technology.
- 🔐 The "Wi-Fi Calls" service is included in the subscriber's tariff plan.
Setting up the function via the standard menu
The easiest and safest way to activate calls over the Internet is to use the standard operating system tools Android in the shell MIUIThe switch layout is consistent across most models, but the names of the options may vary. Typically, the path leads through the SIM cards and mobile networks section.
Open your phone's settings and find the section responsible for connections. In newer interface versions, it's often called "SIM cards and mobile networks." Here, you'll need to select the specific SIM card if you have two installed, as the setting applies individually to each slot.
☑️ Check before switching on
After selecting your SIM card, look for "Wi-Fi Calling" or "Wi-Fi Calling." Toggle the switch to the on position. If the system asks for confirmation or to enter an emergency services address, follow the on-screen instructions. In some cases, a device reboot is required for the changes to take effect.
If the standard switch is missing, it doesn't always mean the feature is unavailable. Manufacturers sometimes hide options depending on the region the firmware is intended for. For example, in Chinese ROM versions, the menu may be hidden until the SIM card detects a location that supports the service.
Activation via the engineering menu and codes
In situations where the standard approach doesn't produce the desired result, you can use the hidden engineering menu. This is a more advanced method that requires caution. Changing unknown parameters in this section may cause instability in the communication module, so proceed with caution.
To enter diagnostic mode, open the Phone app and enter a special code. The most common one for devices Xiaomi — ##869434## or ##4636##After entering the last digit, the menu should open automatically. If this doesn't happen, try the codes ##3646623## or ##4636##.
Dial in the dialer: ##4636##Select: Phone Information
Find: VoWiFi Provisioned
In the list that opens, find the item related to VoWiFiIt may be called "VoWiFi Provisioned" or something similar. Set its value to "Enable" or "True." Be sure to restart your smartphone afterward. This method forces support for the feature at the modem level.
⚠️ Attention: Do not change other settings in the engineering menu, especially those related to LTE frequencies or radio module operating modes. Doing so may result in signal loss or failure to register with the operator's network.
Using third-party applications and methods
If the built-in tools fail to activate the service, enthusiasts often turn to third-party tools. One popular solution is the app 4G Switcher or similar utilities that require the presence of Root rightsHowever, gaining superuser rights voids the warranty and may disrupt the operation of banking applications.
A safer but more complex method is to use ADB (Android Debug Bridge) via a computer. This method allows you to send hidden commands to the system without jailbreaking your phone. You'll need to install ADB drivers on your PC, enable USB debugging in the Developer Options menu, and connect your smartphone with a cable.
| Activation method | Complexity | Risks | Efficiency |
|---|---|---|---|
| Standard menu | Low | None | High |
| Engineering code | Average | Low | Average |
| ADB commands | High | Average | High |
| Root rights | Very high | Tall | Maximum |
To activate via ADB, use a command that changes global system settings. Enter the following into the command line on a computer connected to the phone: adb shell settings put global vocwifi_enabled 1After executing the command, the phone must be rebooted. This method often helps "unlock" features hidden by the carrier.
List of popular ADB commands for Xiaomi
adb shell settings put global vocwifi_enabled 1 (enables VoWiFi)
adb shell settings put global vocwifi_available 1 (makes the feature available)
adb shell settings get global vocwifi_enabled (check status)
Solutions to common problems and errors
Even after proper configuration, users may encounter the icon VoWiFi doesn't appear, and calls don't go through. Most often, the problem lies in a network priority conflict. The smartphone may be trying to connect to a weak 3G signal instead of using fast Wi-Fi.
In the mobile network settings, find "Preferred network type" or "Network mode." Make sure "4G/LTE" or "5G" is selected. Sometimes, temporarily switching to "3G only" mode to force the phone to look for alternative connection paths and then returning to LTE mode helps.
Another common cause is outdated access point name (APN) settings. Go to your mobile network settings, select your SIM card, and go to "Access Point Names (APNs)." Tap the menu (the three dots in the corner) and select "Reset to default settings." This will update your connection settings to your carrier's gateways.
It's also worth checking whether the "Traffic Saver" or "Metered Connection" mode is enabled for system services. If the system considers the connection metered, it may block background processes required for registration with the IMS (IP Multimedia Subsystem) network, which is responsible for voice transmission.
How to tell if a call is made via Wi-Fi
Visual indication is the easiest way to confirm that the technology is working. When the feature is active and the phone is using it for calls, a special symbol appears in the status bar (near the battery or carrier icon). Typically, this is a handset with a Wi-Fi symbol or the words "Wi-Fi Call."
Also, pay attention to the "HD" icon during a call. If it lights up along with the Wi-Fi icon, the call is in high quality over the internet. If the Wi-Fi icon disappears while dialing, the phone has switched to a cell tower.
It's important to note that an incoming call may also display a notification on the lock screen. If you're in an area with no cellular service (in Airplane mode with Wi-Fi enabled) and the call is connected, this is a sure sign the technology is working.
Does using VoWiFi affect my billing?
Technically, traffic is transmitted over the internet, but operators typically charge these minutes as regular voice calls within the network or as part of a minute package. VoWiFi voice traffic is generally not included in your basic internet plan. However, if you're roaming, the rules may differ: some operators consider it a call from within the home network (which is advantageous), while others may charge for outgoing calls. Always check roaming terms with your provider.
Is it possible to call emergency services (112) via Wi-Fi on Xiaomi?
This depends on the country's legislation and carrier support. In most regions, the technology allows you to call emergency services even without a SIM card or with the screen locked, as long as the device can connect to any available carrier's network via Wi-Fi. However, you shouldn't rely solely on this—in a critical situation, it's better to look for a direct cellular signal.
Why did the VoWiFi setting disappear after updating Android?
Firmware updates often reset user configurations or change the logic behind operator profiles. The new security patch may also have changed access rights to system network settings. In this case, it's recommended to re-activate via the menu or engineering code, and also check for updates to the Google Play Services app.