Modern smartphones Xiaomi, Redmi and POCO They have the most extensive functionality, but many users are faced with the problem of poor indoor cellular signal, concrete walls, metal frames of buildings or simply distance from the base station can turn conversations into continuous interference and cliffs. It is in such situations that Voice over Wi-Fi technology comes to the rescue, allowing you to make voice calls using an Internet connection instead of the usual one. GSM-It's not just an alternative messenger, it's a complete replacement for traditional telephony, and you're still using your number.
Activating this feature on Xiaomi devices often requires not only setting up the menu, but also understanding how your device works. SIM-Unlike popular apps like WhatsApp or Telegram, it uses native dialing, making it easy and convenient for the other person to communicate at the other end of the wire. MIUI HyperOS, and some operators require additional actions to start the service.
In this article, we will discuss in detail the algorithm for enabling calls over Wi-Fi on various smartphone models, we will look at the nuances of working with Chinese versions of firmware, global builds and discuss why the option may not be available, and we will also focus on security and voice quality, so that you can enjoy crystal clear sound even in the most remote areas of coverage.
What is VoWiFi and how does it work on Xiaomi?
Voice over Wi-Fi (VoWiFi) is a standard for voice calls over the Internet. IP-Unlike VoIP applications that run on top of the Internet connection and require separate software from both interlocutors, VoWiFi is integrated directly into the phone system. For the user, this means that you dial a number from a regular “bell ringer”, and the smartphone decides through which network to call – through a base station or through an accessible Wi-Fi point.
The principle of the operation is to encrypt voice traffic and transmit it through the router to the network of the operator. Xiaomi and Redmi smartphones support this protocol at the hardware level, but the software implementation depends on the regional version of the firmware and the operator's settings. If the signal of the cellular network is weak, the phone will automatically switch to Wi-Fi, ensuring the continuity of the conversation, this is especially true for owners of devices living in thick walls or in rural areas.
⚠️ Note: Using VoWiFi consumes internet connection traffic. Make sure your data plan allows data transfer, or connect an unlimited package to avoid unforeseen costs.
A key advantage is the high quality of sound, often surpassing standard HD Voice in 3G networks. In addition, the technology saves battery power, since a Wi-Fi module requires less energy to maintain a stable connection in the room than a cellular module that constantly tries to “pierce” the signal through obstacles. On devices with a MIUI shell, the implementation of this function may differ depending on the year of the model.
Verification of support of the technology by the operator and SIM-card
Before you get into the settings of your smartphone, you need to make sure that your mobile operator provides VoWiFi services. Not all companies have implemented this technology in their networks, and even if it is claimed, it can only work in certain regions or at specific tariffs.
It is also important to consider your condition. SIM-Older cards that were released years ago may not support the necessary encryption and authorization protocols, in which case even Xiaomi’s most powerful flagship won’t be able to activate the feature. SIM-cards for a new one in the operator’s cabin, which takes only a few minutes, but is a prerequisite.
- 📱 Make sure your plan provides for the possibility of connecting additional communication options.
- 🔄 Check the relevance of the firmware SIM-Cards from the operator (often solved by replacing plastic).
- 🌍 Check whether VoWiFi is working in your area of residence for the operator you choose.
- 🆔 Make sure that the number is registered to you and does not have locks on the part of the operator.
Some operators require the activation of the service through a personal account or USSD-Without this step, the phone will see the Wi-Fi network, but the VoWiFi icon or HD It is also worth remembering that when calling over Wi-Fi, your number is determined as a local number, which can be important when roaming abroad - in many cases, this avoids incoming and outgoing tariffs.
Basic Wi-Fi Call Configuration in MIUI and HyperOS
If you're convinced that the service is supported by the operator, you can go to the settings of the smartphone. The interface of the MIUI shell or the new HyperOS may vary slightly depending on the version of Android, but the logic remains the same. The first thing you need to connect the device to a stable Wi-Fi network, because without an active Internet connection, the menu item can be hidden or inactive.
To access settings, open the Phone app and go to the settings menu, which is usually hidden under three dots or a gear. Here, look for the section related to accounts or special features. On global firmware versions, the path often looks like Settings. → SIM-maps and mobile networks → Calls over Wi-Fi. If you're using the Chinese version of firmware (CN ROM), The path may be different and require switching the region.
Path to setup (example):
Settings ->SIM- Maps and Mobile Networks -> Select SIM- Card -> Wi-Fi Calls -> EnableIn some cases, the switch may be directly in the notification curtain. Pull the curtain down to the end and look for an icon that says Wi-Fi Calling or Wi-Fi Calling. If there is no icon, click on the edit pencil and add it from the list of available widgets. This is the fastest way to manage the function in everyday use.
☑️ Checklist of VoWiFi activation
After the function is turned on, the corresponding indicator should appear in the status bar. This can be a pipe icon with a Wi-Fi symbol or the inscription Wi-Fi Call. If the icon appears but disappears when you try to call, check the stability of the router connection. For high-quality communication, it is recommended to speed at least 1 Mbit / s and low ping to the operator's servers.
Activation of hidden functions through the engineering menu and region change
It is often the case that the operator supports the technology, SIM-The map is new, but Xiaomi does not have the right switch in its settings, a common situation for devices imported from China or for regions where the operator has not yet been officially certified by Xiaomi.
To do this, go to Settings → Advanced Settings → Region and select a country where VoWiFi is accurately running and certified (such as India, Indonesia or the European Union). Once you change region, the phone will reload network profiles, and hidden menu items can be accessed. This is a secure method that does not require root rights.
| Region | The probability of a menu | Impact on the system | Recommended operator |
|---|---|---|---|
| Russia | Medium | Standard settings | MTS, Beeline |
| India | Tall. | Adding local services | Jio, Airtel |
| Indonesia | Tall. | Minimum changes | Telkomsel |
| Germany | Medium | European standards | Telekom |
If the region change didn't work, you can try activating the feature through the engineering menu, although newer versions of Android often block access to it. Try entering the dialer code ##869434## or ##4636##. In the menu that opens, look for the Phone Information section and the VoWiFi Provisioned option. If the slider is active, turn it on. However, this method does not work on all models and can be blocked by the manufacturer.
⚠️ Note: Region change may affect some local applications, weather widgets and news feeds. Once you set up VoWiFi, the region can be reverted back, but the feature may not be displayed visually, although it will work.
Solving Connection and Communication Quality Problems
Even after successful activation, users may experience unstable functionality. Often the problem lies in the settings of the router itself. Some routers models have strict firewall settings or use encryption protocols that conflict with operator voice traffic. First of all, try rebooting the router and smartphone.
Another common cause is conflict with the power saving mode: Xiaomi aggressively optimizes background processes, which can lead to VoWiFi shutdown to save charge, you need to go to the battery settings, find the Phone application or SIP system service, and set the "No Limits" mode.
- 🔌 Turn it off. VPN-Services and proxy services often block ports required for VoWiFi.
- 📡 Switch your router to 5GHz if possible to reduce delays.
- 🛡️ Check antivirus programs for blocking network connections.
- 🔄 Reset network settings in the smartphone menu (Settings) → Connection and sharing → Reset Wi-Fi, mobile networks and Bluetooth).
If the sound quality is low or the voice is interrupted, check the Internet speed on other devices. VoWiFi is critical to packet loss (jitter). Also, it is worth considering that when you move from Wi-Fi to cellular network, the call can be terminated if you do not configure Seamless Handover. Not all operators and smartphones support seamless transition, so it is better to complete the call before leaving the coverage area of the router.
Why does the VoWiFi icon disappear during a conversation?
Differences in settings on global and Chinese versions of firmware
Owners of smartphones ordered from China often face the lack of a VoWiFi menu by default; Chinese firmware versions (CN ROM) are tailored to local operators and may not have certificates to work with foreign networks. Global ROMs usually have a wider set of supported profiles, but there are limitations.
On Chinese firmware with global firmware installed (manually flashed), the problem may be that IMEI and regional databases are not compatible, and in such cases, the use of special activator applications, such as Carrier Config Enabler or VoWiFi Activator, available in the Play Market, helps.
It is important to distinguish between software lock and hardware incompatibility. If the modem in the phone does not physically support the required frequencies or protocols (which is rare for modern Xiaomi), no settings will help, but in 95% of cases it is the software limitations of the region or operator.
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When reflashing the Chinese version to the global, be sure to unlock the bootloader. This will keep the warranty in some service centers and allow you to work correctly with network functions.
It’s also worth noting the interface difference between MIUI 13, 14 and the new HyperOS. In HyperOS, menu logic has become more confusing, and items are often hidden in deep submenu. Look for sections related to Smart Networks or Improved Communications, there may be a setup wizard hiding there that will automatically select the settings for your operator.
The Impact of Android Version and System Updates
With the release of new versions of Android (13, 14, 15), Google is changing the security requirements for network connections. Older versions of MIUI firmware may stop working correctly with VoWiFi after updating the carrier-side security certificates.
Check for updates in the Settings section → The phone. → Version. MIUI. If you have an old build, the system may not know new ones. APN-parameters required for authorization in the network IMS (IP Multimedia Subsystem. IMS Responsible for multimedia services, including voice calls LTE and Wi-Fi.
⚠️ Note: Do not install beta versions of firmware (Beta) ROM) They may contain errors in the modem, which will lead to permanent communication breaks or complete inoperability. SIM-map.
Sometimes after a major system update, the network settings are reset, so you don't have to look for complex codes, you just have to go through the menu switching procedure again. SIM-Also, updates often bring new lists of operators, which can suddenly "unlock" the feature for those who have not previously worked on it.
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Regular system updates are not only new interface features, but also critical security and interoperability patches with carrier networks.