VoWiFi in Xiaomi Redmi smartphones: how it works, why you need and how to configure

Have you ever noticed that in the subway or deep in an office building, your Xiaomi Redmi suddenly stops catching the network, but calls still pass? Chances are you've already used VoWiFi, a technology that many people don't even know about, which has become the standard for modern smartphones, but in the Xiaomi ecosystem it works with its own nuances.

In this article, we’ll look at what VoWiFi (or Wi-Fi Calling) is in Redmi smartphones, how it differs from regular cellular calls, and why carriers don’t always advertise this feature, what Xiaomi models support the technology, how to activate it in settings, and what to do if VoWiFi doesn’t work despite the visible support of the device, and also uncover myths about the impact of VoWiFi on the battery and communication quality.

If you are often in a place with poor coverage 4G/5G (Basements, remote areas, high-rises with thick walls, this feature can be your salvation, but there are pitfalls: not all operators in Russia and the CIS officially support VoWiFi, and some Redmi models require manual adjustment.

What is VoWiFi and how it works in Xiaomi smartphones

VoWiFi (Voice over Wi-Fi) is a technology that allows you to make voice calls and send messages. SMS It's actually a VoLTE analog, but instead of a traditional cell tower, it's a Wi-Fi network. LTE-The main advantage of the network is that calls are made even where the mobile network is absent or extremely weak.

How does it work on Xiaomi Redmi? When a smartphone loses its cellular signal but is connected to Wi-Fi, it automatically (if the feature is enabled) switches voice traffic to the Internet channel.

• 📞 The phone number remains the same – the subscriber sees your normal mobile, not your regular phone number. IP-address.
• 🔄 Switching between VoWiFi and a regular network is smooth (if supported by an operator).
• 📶 The quality of the connection depends on the speed and stability of your Wi-Fi, not on the load of the cell tower.
• 💰 Calls are charged as usual - without additional fees for "Internet telephony".

It's important to understand that VoWiFi is not the same as instant messengers (WhatsApp, Telegram, Viber). IMS (IP Multimedia Subsystem, integrated into the operator's network:

• ✅ Calls are made to any number (including stationary), not only between users of the same messenger.
• ✅ The history of calls is preserved in the standard application "Phone".
• ✅ Emergency call (112, 911, etc.) works even without it. SIM-Cards (if the operator supports the E911 over Wi-Fi).

In smartphones Xiaomi Redmi VoWiFi implemented at the firmware level MIUI, But it depends on three things: device support, operator support, and the right settings. For example, in Russia, VoWiFi officially supports Beeline, MegaFon, and Tele2, but only for certain rates.

Xiaomi Redmi models support VoWiFi

Not all Redmi smartphones are VoWiFi-enabled, and the technology requires a dedicated chip (modem) and firmware support. Here is the current list of models that are guaranteed to support the function (based on the technology). MIUI 12-14 and Android 10-14):

If your model isn't on the list, it doesn't mean VoWiFi isn't exactly supported. For example, some devices on MediaTek Dimensity (like the Redmi Note 12 Turbo) may have hidden support that can be activated via an engineering menu to check for the feature:

1. Open the phone app.
2. Dial ##4636## (Android test menu)
3. Select "Phone Information" → Look at the VoWiFi line.

Attention! On Chinese firmware (for example, on devices purchased on AliExpress without a global version), VoWiFi can be disabled at the software level. MIUI Global or EEA.

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If you see the line “Wi-Fi Calling: Supported” in the test menu (#4636###) but the feature is not in the settings, try updating your firmware to the latest version or reset your network settings in Settings. → SIM-maps and mobile networks → Resetting network settings.

How to turn on VoWiFi on Xiaomi Redmi: step-by-step instructions

If your smartphone supports VoWiFi, you can activate it in 2-3 minutes. MIUI 12–14:

1. Check it out. SIM-VoWiFi only works with your carrier’s nano-SIM (if you have two numbers, choose the main one).
2. Connect to a stable Wi-Fi network (preferably at a speed of 5 Mbps).
3. Open the Settings. → SIM-maps and mobile networks.
4. Choose yours. SIM-map → Calling by Wi-Fi (or Wi-Fi Calling).
5. Activate the switch and confirm the address for emergency calls (if required).

When you turn on the status bar (top right corner of the screen), you'll see a VoWiFi or Wi-Fi Calling icon, and if you don't have one, but the function is on, try:

• 🔄 Reboot your smartphone.
• 📶 Reconnect to Wi-Fi.
• 📱 Update the firmware to the latest version.

On some models (for example, Redmi Note 10), the path to settings may be different:

Settings → Connections and Sharing → Additional → Call over Wi-Fi

SIM-The card is activated and supports VoWiFi (check with the operator)|

Wi-Fi network stable (no frequent breaks)|

The latest version is installed on the smartphone MIUI|

Security settings are off. VPN (can block IMS-traffic)-->

Attention! If VoWiFi calls fail after activation, but the Internet via Wi-Fi works, the problem may be on the operator’s side. For example, MTS in Russia does not officially support VoWiFi for individuals (for corporate customers only).

VoWiFi vs VoLTE: What’s the difference and what’s better

Many people confuse VoWiFi and VoLTE, although these are two different technologies with a common purpose: improving voice quality.

The main difference: VoLTE works over a mobile network and requires coverage. 4G/5G, VoWiFi is over the Internet and can even work in an office without a cell phone, and ideally, both should work together: the smartphone automatically selects the best channel (Wi-Fi or Wi-Fi). LTE) conditionally.

For example, if you are on the subway:

• 🚇 At the station with Wi-Fi: the call will go through VoWiFi.
• 📡 In the paved tunnel 4G: Smartphone to switch to VoLTE.
• 🌑 In the “dead zone” without Wi-Fi and cellular network: the call will not pass (if the messenger is not connected).

Attention! On some Redmi models (like the Note 11 Pro) VoLTE can be disabled when VoWiFi is active. MIUI. Check the settings after activating both functions.

VoWiFi problems on Xiaomi Redmi and how to solve them

Even if your smartphone and carrier support VoWiFi, there may be failures, and here are the most common problems and solutions.

1. VoWiFi is not enabled in the settings

If the Wi-Fi Calling option is not on the menu:

• 📱 Update your firmware to the latest version (via Settings) → The phone. → Updating the system).
• 🌐 Install a global firmware (if you have a Chinese version).
• 🔧 Enable the function through the engineering menu: Dial ##869434## → Choose. SIM → Activate VoWiFi

2 Calls are interrupted or not passed

Causes and solutions:

• 📶 Poor Wi-Fi quality: Connect to another network or reboot your router.
• 🔒 Lockdown IMS-traffic: shut down VPN firewall.
• 📵 Problems with the operator: check the status of the service in the personal account.

3. The battery goes down fast.

VoWiFi can increase battery consumption if:

• 🔋 Wi-Fi module works in high performance mode (try to turn off Wi-Fi 6 in router settings).
• 📡 The smartphone is constantly switching between VoWiFi and VoLTE (disable one of the functions).

On Xiaomi smartphones with MediaTek processors (for example, Redmi) 10C note 11SE) VoWiFi can work unstable due to problems with the modem, in which case only replacing the device or firmware with custom (for example, LineageOS) will help).

VoWiFi and battery: is it true that the function is very discharged smartphone

One of the most common myths is that VoWiFi eats the battery, and it really depends on the conditions of use.

During an active VoWiFi call, battery consumption may be higher than with VoLTE because:

• 📶 Wi-Fi modules consume more energy than 4G-modem (especially on a weak signal).
• 🔄 The smartphone has to support two connections: to Wi-Fi and to the cellular network (for a smooth transition).

However, when you are not calling, VoWiFi has little or no impact on autonomy, and in some scenarios, it even saves power:

• ⚡ In places with poor mobile signal, the smartphone does not waste energy on constant network search.
• 📵 No need to increase the transmission power (as with a weak one) 3G/4G).

To minimize the impact of VoWiFi on the battery:

1. Turn off the function when it is not needed (for example, on the street with a good one). 4G-covering).
2. Use energy-saving Wi-Fi mode in router settings (turn off) 802.11ac, if you don't need it).
3. Update the firmware: in new versions MIUI Optimized battery consumption with VoWiFi.

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VoWiFi only drains the battery during an active call, and the rest of the time it has minimal impact, especially when compared to constantly searching for a weak mobile signal.

VoWiFi abroad: roaming and international calls

One of the hidden features of VoWiFi is the ability to call at home when you are abroad, for example, if you are in Turkey but connected to your local Wi-Fi, calls will be charged as intranet (without roaming surcharges).

The advantages of VoWiFi in roaming:

• 🌍 Calls at the home network tariff (if the operator supports Wi-Fi Calling Roaming).
• 📞 You can call local numbers without buying a local number. SIM-map.
• 🔒 Your primary number is saved (no need to ask friends to call messengers).

Cons and limitations:

• ⚠️ Not all operators support roaming VoWiFi (check before travel).
• 🚫 In some countries (e.g. UAE, China) VoWiFi may be blocked at the provider level.
• 📡 The quality of the connection depends on the local Wi-Fi (there may be a speed limit in hotels).

How to check whether VoWiFi is working in roaming:

1. Before traveling, contact the operator and check for Wi-Fi Calling Roaming support.
2. In the VoWiFi settings on your smartphone, find the option “Roaming Calls” (if any).
3. After arrival, connect to Wi-Fi and make a test call.

Attention! Even if VoWiFi is roaming, SMS You can't get through Wi-Fi, you can use instant messengers or buy a local one for messages. SIM-map.

FAQ: Frequent questions about VoWiFi on Xiaomi Redmi