Setting up MTS calls via Wi-Fi: A complete guide

The problem of unstable mobile service is familiar to many smartphone owners, especially those living in densely populated areas or remote locations. Cellular signals can drop out in basements, thick-walled offices, or country houses, turning ordinary conversations into intermittent and inaudible ones. In such situations, technology comes to the rescue. VoWiFi, which allows you to make voice calls over an Internet connection.

MTS is actively implementing and supporting this feature, making communications available wherever Wi-Fi is available, even if there is no cellular network at all. Voice over Wi-Fi — This isn't just an app like Viber or WhatsApp, but a fully-fledged replacement for traditional voice communication, integrated into your device's standard dialer interface. The sound quality often surpasses that of standard GSM calls, thanks to the use of a wideband audio codec.

Activating this feature doesn't require any complicated technical steps or additional software installation. Simply ensure your smartphone and SIM card meet certain requirements, and select the correct operating mode in your device settings. In this article, we'll cover how to check compatibility, activate the feature, and troubleshoot potential connection issues.

What is VoWiFi and how does it work with MTS?

Technology Voice over Wi-Fi This method transmits voice traffic over IP protocols, bypassing the cellular operator's base stations. For the user, this process is completely transparent: you dial a number in the standard "Phone" app, and the call is routed through a Wi-Fi access point. This is especially important for MTS subscribers living in "radio shadows" or buildings with shielding structures.

The main advantage over messaging apps is that calls are charged according to your main plan. If you have unlimited minutes enabled, calls over Wi-Fi are also free as part of your plan. Furthermore, you can switch between Wi-Fi and mobile data during a call without losing the connection, as long as your device and carrier network support this feature. Seamless Handover.

⚠️ Attention: For the service to function correctly, the router must not block specific ports and protocols used by the operator for voice transmission. On corporate networks or public Wi-Fi (such as cafes and airports), this feature may be unavailable due to local network security settings.

It's important to understand the difference between regular calls made through internet apps and the native smartphone feature. With MTS VoWiFi, your number is identified as your mobile phone, not a random digital ID. This is critical for business communications and caller ID functionality.

Device and SIM card requirements

Before setting up, you need to ensure your equipment is technically ready to work with modern voice protocols. Not all smartphones, even those released several years ago, support this feature at the software level, especially if they are intended for markets outside of Russia.

First, check the list of compatible devices. MTS supports a wide range of models from leading manufacturers, including Apple iPhone (starting with the 5s model and newer), smartphones based on Android (Samsung, Xiaomi, Huawei, Honor, and others). It's also important that your device has the latest operating system installed, as protocol support is often added through software updates.

The second critical component is your SIM card. It must be of the standard USIM (These are typically Nano-SIM or Micro-SIM cards issued in the last 5-7 years.) Older cards, which were used back in the 2G/3G era, may not contain the necessary security profiles to encrypt voice traffic on LTE and Wi-Fi networks.

To check the SIM card status and service support, you can use the following correspondence table:

What should I do if I have an old-style SIM card?

If your SIM card was cut from a larger card or has been in use for a long time, contact an MTS store for a free replacement. The procedure takes a few minutes, and your contacts can be saved to the cloud.

Activation of the service on the operator's side

Unlike many other service options, MTS's Wi-Fi calling feature is often activated automatically when a compatible device registers on the network. However, in some cases, manual confirmation or checking the connection status in the subscriber's personal account is required.

Make sure your phone number doesn't have any restrictive services, such as "Outgoing Call Barring," enabled. It's also worth checking whether you have a basic minute plan, as VoWiFi technology uses your plan's minutes. If your minutes run out, Wi-Fi calls will be charged at the basic plan rate.

You can activate it using USSD commands or the mobile app. The most reliable method is to use the "My MTS" app. The "Wi-Fi Calling" option status is often displayed in the services section. If it's not active, the system may prompt you to activate it with one click. Alternatively, you can contact support via chat or call the short number 0890.

• 📱 Open the "My MTS" app and log in to your account
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• 🔍 Go to the "Services" section or search for "Wi-Fi".
• ✅ Find the "Wi-Fi Calling" option and make sure the switch is active.
• 📞 If the option is not listed, it may already be enabled by default for your plan.

⚠️ Attention: Service terms may vary depending on your region of residence and specific tariff plan. In some rare cases, corporate plans require separate approval from a manager.

Setting up Wi-Fi calling on Android

The process of enabling the function on smartphones running Android The procedure may vary slightly depending on the manufacturer and shell version. However, the logic remains the same: find the corresponding switch in the mobile network settings.

On most devices, the path is as follows: go to Settings, then select Connections or Mobile networkIn this menu, look for the item Wi-Fi calling or Wi-Fi CallingOnce the slider is enabled, the system may request confirmation of the emergency services address (E911), which is a standard safety procedure.

For Samsung devices, the algorithm may look like this: Settings → Connections → Mobile network → Wi-Fi callingXiaomi and Huawei often have a more hidden path: Settings → SIM cards and mobile networks → SIM card use (select MTS) → Wi-Fi callingIt's important to select the SIM card you plan to use for calls if your phone has two.

Pay special attention to the priority settings. The function menu often offers the option to select "Wi-Fi Only," "Prefer Wi-Fi," or "Prefer Mobile Network." For best results in poor coverage areas, it's recommended to select this mode. Prefer Wi-FiThis will force the phone to try to use the internet channel for voice, even if there is a weak cellular signal.

Instructions for iPhone (iOS) users

For smartphone owners Apple We're lucky to have the most unified settings interface. iOS logic dictates that if a feature is supported by the carrier and device, the toggle will appear automatically after installing the latest version of iOS and updating carrier settings.

To activate, go to Settings → CellularIf you have one SIM card, you will immediately see the item Wi-Fi callingIf you're using two SIM cards (or an eSIM), select the specific MTS number from the list and find this switch in its settings. Move the slider to the active position.

The iOS system also allows you to set up call forwarding to other devices (iPad, Mac, Apple Watch). In the same menu, you can enable the "On Other Devices" option, which will allow you to receive calls from your MTS number on your tablet or computer, as long as they are connected to the same Wi-Fi network and iCloud.

• 🍎 Make sure your iOS is updated to the latest version.
• 📡 Check for carrier settings updates (Settings → General → About).
• 🔘 Turn on the "Wi-Fi Calling" toggle switch in your cellular settings.
• 📍 Confirm or update your emergency address when prompted by the system.

Sometimes, after enabling this feature, the "Wi-Fi" prefix may appear in the status bar next to the carrier name. This means the phone is ready to make internet calls. If the prefix doesn't appear, try restarting the device or temporarily turning Airplane Mode on and off.

Troubleshooting and common errors

Even with proper setup, there may be situations where the feature doesn't work or works intermittently. Most often, problems are related to the quality of the internet connection or conflicting network settings. If you see the VoWiFi icon but calls aren't connecting, check your internet speed—a stable connection of at least 100-200 kbps is required for high-quality voice calls.

One common error is blocked ports on the router. If you're using a complex corporate firewall or specific settings on your home router (such as strict parental controls), your carrier's traffic may be filtered. Try connecting to a different Wi-Fi network (for example, sharing internet from another phone) to diagnose the issue.

It's also worth considering that when switching between networks (for example, going outside), a brief connection interruption or delay may occur. This is normal for technology, but if the interruptions are persistent, it might be worth changing the network priority in your phone's settings.

⚠️ Attention: When using VPN services, VoWiFi often stops working. The provider detects that your IP address is in another country or region and blocks voice traffic for security reasons. Disable the VPN before making important calls.

If all else fails, reset your network settings. This will delete saved Wi-Fi passwords and Bluetooth settings, but will return your phone's network settings to factory defaults, which often resolves software conflicts. Here's how to reset: Settings → System → Reset → Reset network settings (on Android) or Settings → General → Transfer or reset iPhone → Reset → Reset Network Settings (on iOS).

Frequently Asked Questions (FAQ)

Does making calls over Wi-Fi use up mobile data?

No, voice traffic using VoWiFi technology does not consume your mobile data plan. Data is transmitted over the Wi-Fi channel. However, if you use the internet (browser, messaging apps) during a call, your data usage for these apps will be used.

Will VoWiFi work when roaming abroad?

Yes, this feature works in international roaming. Moreover, it's a great way to save money: if you're in a Wi-Fi coverage area abroad, incoming and outgoing calls to Russia are often charged as domestic calls (in your home region), rather than roaming rates. Check with your carrier for details.

Why does the Wi-Fi Call icon appear, but calls are made via the cellular network?

This can happen if the cellular signal is strong enough and "Mobile Network" is selected as the priority in the phone settings. The phone may also automatically switch to GSM/LTE if the Wi-Fi signal quality drops or if the internet connection is unstable.

Is it possible to call emergency services (112) via Wi-Fi?

Technically, this capability exists, but it depends on the subscriber's location support on the specific network and phone model. For emergency calls (112, 101, 102, etc.), it is always recommended to use a direct cellular connection, as it provides more accurate geolocation for rescue services.

Does VoWiFi affect battery drain?

The impact is minimal and comparable to normal standby mode on a 4G network. However, if the Wi-Fi signal is very weak, the phone will constantly increase its transmit power to maintain the connection, which can increase battery consumption. In such cases, it's best to switch to the mobile network.