Modern smartphones Xiaomi, working on the shell MIUI or new HyperOS, offer a variety of advanced features to improve connection quality. One of the most popular features is the technology Voice over WiFi, allowing you to make voice calls over a wireless network. This solution is ideal for areas with poor cellular coverage but stable internet.
Many users mistakenly believe that simply connecting to a router is enough for the phone to automatically route calls over the internet. In practice, the setup process Wi-Fi Calling This feature requires the operator to meet several conditions and the device itself to be properly configured. In this article, we'll cover all the details of activating this feature.
It's also worth keeping in mind that settings interfaces may differ depending on the firmware version and the region for which the smartphone was released. Xiaomi The company regularly updates its software, so the layout of some menu items may change. However, the basic operating principles of the technology have remained unchanged over the past few years.
What is VoWiFi technology and how does it work?
Technology Voice over WiFi (often referred to as VoWiFi) is a standard that enables voice calls to be transmitted over IP protocols using a wireless connection instead of a cellular operator's radio channel. Unlike popular instant messaging apps such as Viber or WhatsApp, this function is integrated directly into the standard phone book and dialer application.
The main advantage is that you don't need to convince your caller to install a specific app or have a social media account. You dial a regular number, and the system automatically decides whether to route the call through a cell tower or an internet connection. This process is often seamless for the user if the carrier supports automatic switching.
It's important to understand the difference between making calls via messaging apps and using your phone's native calling feature. The former uses the app's data traffic, while the latter uses your plan's voice traffic, but transmitted via a different technical method. Sound quality when using HD-voice via Wi-Fi is often higher than with a weak GSM signal.
⚠️ Please note: This feature depends on your mobile carrier's support. Even if your phone allows this setting, calls will not work without activating the service with your carrier.
The operating principle is based on tunneling voice packets through a secure connection to the operator's gateway. This ensures call security and number protection. Smartphone Xiaomi It monitors signal quality in the background and seamlessly switches calls between networks if necessary, although in practice, when leaving the Wi-Fi zone, the call may be interrupted if handover is not configured.
Checking operator and tariff compatibility
Before delving into deep settings Android or MIUI, you need to make sure your mobile operator offers VoWiFi. This technology is being gradually implemented in Russia and the CIS countries, and the list of supporting companies is constantly growing. Major market players have long since implemented this feature for their subscribers.
Activation often requires not only network support but also the activation of a specific option or a change in tariff plan. Some carriers offer Wi-Fi calling as part of premium plans or as a separate paid service, although the trend is toward free access for everyone.
You can check this through your operator's personal account or with a special USSD command. It's also worth making sure your SIM card isn't too old. In some cases, replacing the SIM card with a standard card is required for modern communication protocols to function correctly. USIM with support for new safety standards.
- 📱 Go to the "My Operator" app and find the communication services section.
- 🔍 In the service search, enter "Wi-Fi Calling" or "Wi-Fi Calling".
- ✅ If the service is available, activate it using a switch or by sending a command.
- 💳 Check your plan terms: sometimes the service is only free within your home network.
It's worth noting that even if your operator supports this feature, it may not appear in your phone's menu if your device isn't certified to work with that provider's network. Xiaomi has many modifications for different markets (Global, China, Russia, Europe), and the firmware may limit access to functions depending on the inserted SIM card.
Basic setup via the standard MIUI menu
If you've verified that your carrier supports the service, the next step is to find the corresponding switch in your smartphone's interface. In current versions of the shell MIUI 12, 13, 14 And HyperOS The developers have tried to make this item accessible, although sometimes it is hidden in a submenu.
The standard activation process is as follows: open the Phone app, go to Settings (usually the three dots or gear icon in the corner), and find the section associated with your account or carrier. This is usually where the required toggle switch is located.
In some cases, the path may differ. For example, in some builds, the menu is located in the general system settings. In such cases, you should follow this path: Settings → SIM cards and mobile networks → Select SIM card (your card) → Wi-Fi callingThe presence of this item is the first sign that the phone is technically ready for use.
☑️ Menu inclusion algorithm
Once the switch is turned on, a special icon should appear in the status bar (at the top of the screen, next to the signal strength). It may look like a telephone handset with a Wi-Fi symbol or the words WIf the icon appears but is gray, it means the phone is ready, but the connection to the operator's server has not yet been established.
| Icon status | Indication color | Meaning |
|---|---|---|
| Active | White / Blue | Calls are made via Wi-Fi |
| Ready | Grey | The feature is enabled, but there is no Wi-Fi network. |
| Disabled | Absent | The service is not activated in the menu |
| Error | Flashing | Problem with operator authorization |
Hidden settings and engineering menu
There are situations where the carrier supports the technology, the SIM card is new, and the menu option simply isn't there. This often happens on global versions. Xiaomi With SIM cards from local operators. In such cases, hidden engineering menus accessible through special codes come to the rescue.
One of the most effective ways is to use the hidden testing menu. To do this, open the Phone app and enter the code ##869434##This code is designed to unlock hidden VoWiFi features on devices XiaomiAfter entering the code, you should see a notification that says "VoWiFi carrier check was disabled" or a similar success message.
##869434##After successfully executing the command, you need to reboot your smartphone. Often, after a reboot, a previously hidden option appears in the standard settings menu. If the code doesn't work (nothing happens or an error occurs), try an alternative method through the testing menu. ##4636##.
In the testing menu (4636) select "Phone Information." Scroll down to "VoWiFi Provisioned" or "Set preferred network type." Here, you can try manually setting the network priority or enabling the carrier support flag. Be careful: changing settings in the engineering menu may affect the stability of the communication module.
⚠️ Caution: Do not change settings in the engineering menu whose meaning you do not know. Resetting the radio module may result in temporary loss of connection or the inability to register with the network.
If these methods don't help, it's possible that your specific hardware modem or firmware version doesn't support the required protocol for your carrier. In this case, you'll need to wait for updates from the manufacturer or use alternative apps.
What to do if the codes don't work?
If entering the codes doesn't work, your Android version may be blocking access to hidden menus. Try installing Activity Launcher from Google Play, navigate to "Settings" → "SIM Cards," and try launching hidden activities related to IMS or VoWiFi.
Alternative calling apps
When a native function VoWiFi If your phone number is unavailable or not working properly, substitute apps come to the rescue. Mobile operators often release their own software that allows you to call regular numbers over the internet, using your primary number as an identifier.
For example, major carriers offer "second numbers" apps or enhanced calling services. These operate on the VoIP principle, but to the other end of the line, you appear as a regular mobile phone caller. This is an excellent solution for those who often find themselves in areas with poor GSM signal strength.
- 📞 Official operator applications: Many providers offer their own solutions for making calls over the Internet.
- 🌐 Messengers with access to phones: Services like Skype or Viber Out allow you to call mobile phones for a small fee.
- 📱 Second line applications: Programs that provide a virtual number for calls via a data channel.
The main drawback of such solutions is that the caller must be online, have the app installed, and have an authorized account. Furthermore, they consume mobile data or Wi-Fi, which can be costly without unlimited plans. However, the connection quality on such apps is often better than on congested cellular networks.
Troubleshooting connection issues and errors
Even with proper setup, users may encounter issues. The most common is the Wi-Fi Calling icon becoming grayed out or constantly disappearing. This usually indicates issues with the wireless connection or router settings.
For VoWiFi to work reliably, the router must process SIP packets correctly. Sometimes disabling this feature helps. WMM (Wi-Fi Multimedia) in the router settings or, conversely, enable it. It's also worth checking if ports are blocked in the router's firewall, although this isn't required for most operators.
Another issue is network priority conflicts. The phone may latch onto a weak Wi-Fi signal while ignoring a strong 4G connection, or vice versa. In the settings Xiaomi There's often a "Preferred network type" option. Make sure it's not strictly limited to 2G/3G only if you're in an LTE zone.
If all else fails, try resetting your network settings. This won't delete your photos or contacts, but it will reset all Wi-Fi, Bluetooth, and mobile network connections to factory settings. Here's how to reset: Settings → Connection and sharing → Reset Wi-Fi, mobile networks, and Bluetooth.
⚠️ Note: After resetting your network settings, you will have to re-enter passwords for all saved Wi-Fi networks and Bluetooth devices.
Frequently Asked Questions (FAQ)
Does sound quality decrease when making calls over Wi-Fi?
Sound quality directly depends on the speed and stability of your internet connection. With a good Wi-Fi connection (over 1 Mbps), sound is often clearer and richer (HD Voice) than with a poor cell tower signal. However, network congestion can cause delays or a robotic voice.
Does making such calls use up my internet traffic?
Technically, data usage is used, but most modern operators don't charge for data used for VoWiFi if the call is to numbers within your home network. However, it's best to check this in your plan's terms and conditions to avoid any surprises.
Is it possible to call emergency numbers (112, 102) via Wi-Fi?
In most cases, emergency calls via VoWiFi are unsupported or unreliable, as the system cannot accurately determine your location (IP geolocation is less accurate than cell tower geolocation). When attempting such a call, your phone may automatically switch to GSM.
Why did the feature disappear after the MIUI update?
Firmware updates may reset hidden settings or change the list of supported carriers. Try entering the engineering activation code again or check if the device's region has changed in the system settings.