Setting up a mobile connection via Wi-Fi: VoWiFi and data transfer

Mobile Wi-Fi is a technology that allows you to use your home or office network for making calls (VoWiFi) and mobile data transmission instead of traditional operator towers. This approach solves two key problems: poor coverage in rooms with thick walls and saving mobile trafficwhen you are connected to Wi-Fi.

In this article we will look at how to enable VoWiFi (voice calls over Wi-Fi) on Android And iPhoneWe'll also explain why Wi-Fi sometimes performs worse than carrier network performance. You'll learn which carriers support this feature in 2026, how to check your phone's compatibility, and what to do if calls are dropping or data isn't transferring.

Important: technology VoWiFi and data transfer via Wi-Fi are not the same thing. The former is responsible for voice communication, the second one is for mobile InternetWe will consider both options, as their settings are different.

What is mobile Wi-Fi and why is it needed?

Technology VoWiFi (Voice over Wi-Fi) allows you to make calls over your internet connection instead of your cellular network. This is especially useful in places where the signal is weak, such as basements, elevators, or country houses with thick walls. Your phone number remains the same, and the person you're calling won't even notice you're talking over Wi-Fi.

The second function is - mobile data transfer via Wi-Fi — works differently. It allows your smartphone to use Wi-Fi to download content (websites, videos, updates), but at the same time traffic is debited from your mobile account, not from your home internet connection. This applies to plans with unlimited mobile data but limited Wi-Fi.

• 📞 VoWiFi — Wi-Fi calls (saves battery, improves connection in poor coverage areas).
• 🌐 Mobile data via Wi-Fi — Internet traffic goes via Wi-Fi, but is debited from your mobile account (useful for unlimited plans).
• ⚡ Wi-Fi Calling — an alternative name for VoWiFi among some operators (for example, MTS or Beeline).

Not all operators and phones support these features. For example, Tele2 may offer VoWiFi only on certain plans, and Yota — does not support mobile data transfer over Wi-Fi at all. Check compatibility before setting up.

Which phones and carriers support VoWiFi and mobile data over Wi-Fi?

Function VoWiFi It is available on most modern smartphones, but its support depends on three factors:

1. Phone model - there must be compatible chips and firmware (for example, iPhone 6s and newer, Samsung Galaxy S8 and newer, Xiaomi Redmi Note 10 etc.).
2. Telecom operator - Not all provide this service (see table below).
3. Tariff plan — sometimes VoWiFi is only available on expensive plans.

To find out if your phone supports VoWiFi, check your settings or use the official list of devices on your carrier's website. For example, MTS There is page with supported models.

⚠️ Attention: VoWiFi and Wi-Fi data transfer terms are subject to change. Before setting up, please check your operator account or contact customer support for the latest information.

How to enable VoWiFi (Wi-Fi calling) on ​​Android

Setting up VoWiFi on Android depends on the version of the operating system and the manufacturer's shell (for example, MIUI on Xiaomi or One UI on Samsung). We'll look at a universal method that works on most devices.

Connect to a stable Wi-Fi network|Check that your SIM card is active|Update your phone's firmware to the latest version|Make sure your carrier supports VoWiFi-->

Steps to enable:

1. Open Settings → Network and Internet (or Connections on Samsung).
2. Select Mobile network → Additionally (or Calls on some phones).
3. Find the item Wi-Fi calling or VoWiFi and activate the switch.
4. If prompted, select your SIM card (if you have more than one).
5. Confirm the activation - an icon will appear on the screen Wi-Fi Calling or VoWiFi in the status bar.

On some phones (eg. Huawei or Honor) the path may differ: Settings → Wireless & networks → Wi-Fi calling.

If the option is missing, it means:

• 📱 Your phone does not support VoWiFi.
• 📡 Your operator does not provide this service on your plan.
• 🔄 You need to update the firmware (check in Settings → System → Software Update).

How to enable VoWiFi on iPhone (iOS)

On iPhone setting VoWiFi easier than on Android, but requires the operator to support this feature. Models starting from iPhone 6s (inclusive) on iOS 12 and newer.

Instructions:

1. Open Settings → Cellular communications.
2. Select Wi-Fi calling (or Wi-Fi Calling).
3. Activate the switch Wi-Fi calling on this iPhone.
4. In the window that appears, click Turn on.
5. If the operator requires confirmation, enter the code from the SMS.

After turning on, the following message will appear in the status bar: Wi-Fi next to the operator's name. If it's not there, check:

• 🔄 Update iOS to the latest version (Settings → General → Software Update).
• 📋 Make sure your plan supports VoWiFi (a list of plans is usually available on the operator's website).
• 🔄 Restart your phone if the option does not appear immediately.

⚠️ Attention: On iPhone, VoWiFi may automatically turn off when roaming. To prevent this, enable this option. Wi-Fi calls while roaming in the same settings.

How to set up mobile data transfer via Wi-Fi

This feature allows your phone to use Wi-Fi to transmit mobile traffic, but deduct it from your plan. For example, if you have unlimited mobile data but limited Wi-Fi, you can trick your phone into thinking it's connected to a mobile network when it's actually using Wi-Fi.

Important: Not all operators support this feature, and setting it up may violate your plan's terms. Please check the terms in your personal account before using it.

On Android This can be done through Developer mode:

1. Activate Developer mode:

   Settings → About phone → Build number (press 7 times)

2. Return to Settings → System → For developers.
3. Find the option Mobile data is always active and turn it on.
4. Next, select Data transmission network → Wi-Fi.

On iPhone there is no such function - Apple does not allow forced redirection of mobile traffic over Wi-Fi. However, a workaround can be used with a VPN or special applications (for example, Speedify), but this requires additional settings.

What happens if the operator detects mobile traffic being transmitted via Wi-Fi?

Some operators block such connections or transfer them to paid roaming. In the worst case, they can suspend your plan for violating the rules. Check the terms in your contract before using.

Why mobile Wi-Fi may be performing poorly and how to fix it

Sometimes calls through VoWiFi Interruptions occur, and mobile data via Wi-Fi is slower than direct data. There may be various reasons:

• 📶 Weak Wi-Fi signal — if the router is far away or there is interference, the connection will be unstable.
• 🔄 Conflict with other functions - For example, Wi-Fi Assist On iPhone, it automatically switches to mobile data if Wi-Fi is weak.
• 🔒 Blocking by operator — Some operators limit VoWiFi in roaming or on certain tariffs.
• 📱 Problems with firmware - outdated software can cause crashes.

How to improve connection quality:

1. Reboot your router — sometimes a simple reboot helps.
2. Use 5 GHz - If your router supports two frequencies, connect to the network 5 GHz (it is less busy).
3. Turn off battery saving — Power saving modes may limit background data transfer.
4. Update your phone's firmware — Manufacturers regularly fix VoWiFi bugs.

If problems persist, try:

• 🔧 Specify manually DNS (For example, 8.8.8.8 from Google) in the Wi-Fi settings.
• 📵 Disable Wi-Fi Calling and use only the mobile network if connection quality is critical.
• 📞 Call the operator's support - sometimes the problem is on their end (for example, the settings are lost) IMS).

Alternative ways to improve connectivity without VoWiFi

If your carrier or phone does not support VoWiFi, you can use alternative solutions:

• 📲 Wi-Fi calling apps — WhatsApp, Telegram, Skype or Zoom allow you to make calls over the internet, but the other person must also be using the app.
• 📡 Wi-Fi repeater - If the problem is a weak signal, install a repeater to increase coverage.
• 🔄 Airplane mode with Wi-Fi enabled - sometimes this helps to stabilize the connection.
• 📶 Femtocell — a mini-tower for the operator at home (for example, MTS Connect or MegaFon Home).

If you really need to save your phone number, the best option is femtocellIt connects to your router and creates the operator's coverage area at home. The downside is that it's usually a paid service (200 to 500 rubles per month).

For business users, some operators offer corporate solutions - For example, MTS Business Connect or MegaFon OfficeThese include enhanced VoWiFi support and priority call quality.

FAQ: Frequently asked questions about mobile Wi-Fi

Is it possible to use VoWiFi abroad to avoid roaming charges?

Yes, but not all operators allow this. For example, MTS And Megaphone They support VoWiFi while roaming, but may incur additional charges. Check the terms in your account or with support. Also, make sure the option is enabled in your phone settings. Wi-Fi calls while roaming (on iPhone) or Roaming over Wi-Fi (on some Android).

Why does mobile internet disappear after turning on VoWiFi?

This may be due to a settings conflict. Try:

1. Disable Wi-Fi Assist (on iPhone) or Automatic switching to mobile network (on Android).
2. Specify manually APN in the mobile network settings (the parameters can be found on the operator’s website).
3. Restart your phone and router.

If the problem persists, contact your operator's support team—your tariff plan may have restrictions.

Is it possible to make calls via VoWiFi without a SIM card?

No, VoWiFi requires an active SIM card from the same carrier that provides the service. Without a SIM card, Wi-Fi calling is only possible through third-party apps (WhatsApp, Skype etc.).

How do I disable mobile data over Wi-Fi?

On Android:

1. Open Settings → System → Developer Options.
2. Turn it off Mobile data is always active.
3. Restore the setting Data transmission network to the default value.

On iPhone There is no such function, but you can use it Modem mode in the opposite direction (distributing Wi-Fi from the phone, rather than connecting to it).

Do VoWiFi and mobile data over Wi-Fi drain battery life?

VoWiFi uses less battery than regular cellular calls because the phone doesn't waste energy searching for a cell tower. However, if the Wi-Fi signal is weak, battery consumption may increase. Mobile data over Wi-Fi has little impact on battery life because the traffic goes through the router, not the mobile network.