How to call via Wi-Fi to mobile for free: setup Xiaomi

Modern Xiaomi, Redmi and POCO smartphones have powerful features that often remain hidden from the eyes of the average user. One of these “sleeping” features is the ability to make voice calls exclusively over the Internet connection, bypassing standard cell towers. This technology, known as VoWiFi (Voice over Wi-Fi), allows you to maintain communication even in places with “dead areas” of coverage, such as basements, thick-walled office buildings or remote suburban areas.

Many device owners mistakenly believe that calls always need active phone service. SIM-In fact, if you have access to a Wi-Fi hotspot, your phone can become a full-fledged communication tool without being tied to a cell phone operator at the time of a call. It is not only convenient, but also often cost-effective, especially when traveling internationally.

In this guide, we will discuss in detail how to activate this option on the MIUI or HyperOS shell, what nuances exist in different Big Three operators and virtual operators, and also answer questions about charging such calls.

What is VoWiFi Technology and How Does It Work for Xiaomi?

VoWiFi is an extension of the VoLTE standard, which allows voice traffic to be transmitted over IP protocols on wireless access networks. Unlike popular messengers like Viber or WhatsApp, which require the installation of a separate application from the interlocutor, VoWiFi uses the standard interface of the “caller” of your smartphone. To the person on the other end of the wire, your call looks like a normal mobile phone, and it is displayed in the call history as a standard number.

The principle of operation on Xiaomi devices is based on deep integration of software modules with network equipment of the operator. When you dial a number, the phone analyzes the available networks. If the cellular signal is weaker than a certain threshold, and Wi-Fi is available and supports the function, the device automatically switches the voice channel to the Internet protocol. GSM-communication, as a broadband audio codec is used HD Voice.

⚠️ Attention: The function requires the support of the technology from your mobile operator. Even if the phone is set up perfectly, without activating the service on the provider's side, calls will not go.

It's important to understand the difference between Wi-Fi calls and Internet applications. In the first case, you use your real phone number and your carrier's data plan just by changing the physical data channel. In the second case, you depend on the servers of the third party and the account in their ecosystem. The key advantage of VoWiFi is transparency for the user: you just call, and the phone chooses the best route.

Compatibility check: operator and tariff plan

Before you get into the settings of your smartphone, you need to make sure that your mobile operator provides VoWiFi. In Russia and CIS countries, this technology is actively being introduced, but the list of supported tariffs and regions may differ. The largest market players such as MTS, MegaFon, Beeline and Tele2 have long launched pilot projects and full-fledged functionality for subscribers.

Often, activation requires that there are no debts in the account, and that SIM-The map was replaced with a more modern version with support USIM, Some virtual operators, like Tinkoff Mobile or Yota, also support the technology, but may require manual registration of profiles or change of profiles. APN.

• 📱 MTS: The service is free, activated automatically on the supported tariffs of MTS Smart and other lines.
• 🚀 MegaFon: It is required to enable the service "Calls via Wi-Fi" in the personal account or through the USSD-team.
• 🐝 Beeline: The function is available to subscribers of postpaid and some prepaid tariffs, the setting is often automatic.
• 🟢 Tele2: Support is implemented gradually, you need to check the relevance for your region in the application “My”. Tele2».

The cost of a minute of conversation over Wi-Fi usually corresponds to the cost of a minute in your tariff within your home network. However, if you are on international roaming, the rules may change: some operators charge such calls as incoming / outgoing in the home region, making the technology a lifesaver for travelers.

Basic VoWiFi settings in MIUI and HyperOS

Xiaomi’s shell interface may vary slightly depending on the Android version and regional firmware (Global, EEA, China).However, the hidden settings search algorithm remains the same. In most modern models, starting with the Xiaomi Mi 9, Redmi Note 8 and later, the feature is built-in at the system level, but sometimes hidden from the user.

To start, go to the settings menu. The path usually looks like this: Settings. → SIM-Select the SIM card you want to activate your Internet calls for. If the carrier is supported and the phone is compatible, you'll see a Wi-Fi Call switch or Wi-Fi Calling switch.

Sequence of action:


1. Open "Settings"




2. Go to SIM-maps and mobile networks




3. Select the desired SIM- card




4.Look for the item "Wi-Fi Calls"




5. Activate the switch

If the switch is missing, try typing the engineering code in the dial menu: ##869434##. The MiuiVoWiFiTest window that appears should have the option "VoWiFi Carrier check." If it is active, turn it off (or turn it on, depending on the version) to unlock the menu in the settings.

Advanced activation through engineering menu and codes

In cases where the standard path is not successful, you have to go deeper, and that's true for people who have changed carriers, but the phone thinks the old SIM card is still inside, or for people who have Chinese versions of smartphones, and here we're going to need access to a hidden test menu.

Use the code ##86583##. In the window that opens, you will see the VoWiFi Carrier check status. If it says "Disabled," click the button to change the status to "Enabled." This action removes the software lock that the firmware region imposes. After this procedure, be sure to restart the smartphone.

⚠️ Warning: Do not change other options in the engineering menu unless you are sure of their purpose.Resetting the radio module settings can lead to temporary loss of communication or incorrect operation. GPS.

There is also a method through the Activity Launcher app available on the Google Play store. Finding activity processes in the list of system processes called com.android.settings/.Settings$WifiCallingSettingsActivity, you can force a hidden VoWiFi settings menu to run. This does not work on all versions of MIUI, but is a secure software method.

Operator support table and APN settings

The technology often requires the correct setup of APN access points to work properly, and if automatic settings are not applied, you can manually make them. Below is a table with current parameters for the main operators that support VoWiFi.

To change these settings, go to the Settings path. → SIM-maps and mobile networks → (Yours. SIM) → Access points (APN). Click on plus or select an existing point, edit the "Name" and "Type" fields. APN», adding a semicolonial ims. Save the profile and select it as active.

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If the Internet stopped working after changing the APN, click the menu (three dots) in the corner of the APN settings screen and select Reset to the original settings.

The solution to the problem: why VoWiFi does not work

Even when set up correctly, there can be situations where the Wi-Fi icon doesn't appear and calls are disrupted. One common cause is software version conflict. Operators update their profiles, and if your Xiaomi firmware is too old, it may not contain the latest security certificates.

Check for system updates. Go to Settings → About Phone → MIUI version. If a new version is available, install it. Also, the problem may be in the router: some home Internet providers block certain ports or protocols (SIPs) required for voice communication. Try switching to another carrier's mobile hotspot for verification.

• 🔄 Reboot: A banal but effective way to reboot your phone and router.
• ✈️ Flight mode: Turn on and off flight mode to force re-registration on the network.
• 🗑️ Network Settings Reset: In the Connection and Sharing menu, find a Wi-Fi and mobile network reset.

If nothing works, your plan may not support this option. Call the operator's support and check if your number has VoWiFi activated. USSD-code for primary profile activation on the network.

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90% of VoWiFi problems are solved by updating the phone’s firmware or adding an “ims” setting to the APN hotspot settings.

Frequently Asked Questions (FAQ)