How to Make Wi-Fi Calls on MTS: A Complete Guide

Modern mobile communications don't always guarantee stable coverage, especially in deep spaces, offices with thick walls, or country houses. It's in these situations that technology comes to the rescue. Voice over Wi-Fi, allowing you to make and receive voice calls over an internet connection. For MTS subscribers, this feature has become a quality standard, providing crystal-clear sound in areas where regular cellular service can be spotty or completely absent.

Activating this service doesn't require any complicated technical steps or third-party apps, as the technology is built directly into your smartphone's software. However, for proper operation, your device must support the standard and have the appropriate settings. In this article, we'll cover in detail how to make Wi-Fi calls on MTS, which phone models support this feature, and what to do if it doesn't activate automatically.

Using the internet for voice communications opens up new opportunities for users in areas with poor cell phone coverage. It's not just an alternative, but a complete replacement for traditional communication channels, operating transparently for the user. You dial the number as usual, and the connection is established over the wireless network, bypassing congested base stations.

What is VoWiFi technology and how does it work at MTS?

Technology Voice over Wi-Fi (often abbreviated to VoWiFi) is the transmission of voice traffic as packet data over IP. Unlike popular messaging apps, where audio is transmitted through the app's servers, VoWiFi utilizes the telecom operator's own infrastructure. For MTS, this means that calls are routed through the operator's gateways, ensuring high call quality and the ability to identify callers even when calling through a home router.

The main advantage is that VoWiFi It even works in airplane mode if Wi-Fi is enabled. This is especially useful for traveling: while abroad, you can connect to your hotel's local network and call Russian numbers at your home region's rates, avoiding roaming charges. The operator's network treats such calls as local, since you're technically within the virtual cell's coverage area.

⚠️ Attention: Voice call quality directly depends on the stability and bandwidth of your internet connection. If the network is overloaded with other devices, delays or interruptions are possible.

It's important to understand the difference between VoWiFi and calls made through apps like WhatsApp or Telegram. With MTS, you use your primary number, and your balance is debited according to your plan, rather than using your general data plan (although a minimal amount of service data is still exchanged). This makes the technology ideal for business calls where reliability and caller identification are crucial.

Checking smartphone and tariff compatibility

Before setting up, you need to make sure your device is technically capable of supporting this protocol. Not all phone models, even modern ones, have built-in VoWiFi support for specific carriers. This feature is typically available on smartphones released after 2016-2017, running current operating system versions.

The list of supported devices is constantly updated. MTS regularly adds new models to its list. Most often, owners of flagship models from leading manufacturers experience no issues. However, if you have a budget model or a device imported from abroad (a Chinese version without global firmware), this feature may be missing.

Below is a table of popular brands and series that are guaranteed to support Wi-Fi calling with a given operator:

When it comes to tariff plans, MTS is loyal. The service VoWiFi Available on almost all archived and current plans, including the "Tarifische," "Nash Smart," "Ultra" and corporate plans. There is no separate subscription fee for Wi-Fi calling. Minutes are charged from your main plan, and if your plan is exhausted, they are charged per minute.

How to enable Wi-Fi calling on iPhone

Apple smartphone owners are the luckiest of all: the activation process is extremely simplified and often happens automatically. If your MTS SIM card is inserted into your iPhone and the device is connected to the internet, the carrier may automatically send the configuration profile. However, if that doesn't happen, you'll have to manually activate it through the settings.

First, make sure your phone is running the latest available version of iOS. Then, check if your carrier profile is up to date. You can do this in the section Basics → About this device, scrolling down. If an update is available, a notification will appear. After updating your profile, follow these steps:

• 📱 Open the "Settings" menu and go to the "Cellular" section.
• 📞 Select "Wi-Fi Calling" and turn on the switch.
• 📍 Confirm your address for emergency services (this is a mandatory requirement by regulators).
• 🔄 Reboot your device to apply the changes.

After turning it on, a phone icon or inscription will appear in the status bar (top right) next to the operator’s name. MTS Wi-FiThis indicates that the phone is ready to route voice calls over the wireless network. If the icon doesn't appear, try turning Airplane Mode off and on again.

Setting up VoWiFi on Android (Samsung, Xiaomi, and others)

In the Android world, the situation is a bit more varied due to the multitude of skins from different manufacturers. The operating principle is the same, but the menu names may differ. On most modern smartphones, this function is hidden in the main communication settings. It's important that the device is running the original firmware or the global version, as the menu may be truncated on Chinese builds (CN Version).

Let's look at an example for Samsung devices. Go to Settings → Connections → Mobile networkThere you'll find the "Wi-Fi Calling" option. On Xiaomi smartphones (MIUI/HyperOS), the path often looks like this: Settings → SIM cards and mobile networks → Select MTS SIM card → Use Wi-Fi for callsIf the item is not in the menu, try searching for "Wi-Fi" in the settings.

⚠️ Attention: On some Xiaomi and Huawei models, this feature may be hidden. Try entering the code. ##869434## into the dialer. If the message "Wi-Fi Calling allowed" appears, the hidden flag is enabled. If "not allowed," it can't be enabled programmatically.

For devices where the standard method doesn't work, you can try activating via the engineering menu, although this requires caution. Enter the code ##4636##, select "About Phone," and find the "Turn off Wi-Fi Calling" switch (if it's on, turn it off, and vice versa). However, this method doesn't work on all Android versions.

What to do if the item is not in the menu?

If you don't see the VoWiFi option in the standard Android menu, try resetting your network settings. Go to Settings → System → Reset → Reset Wi-Fi, mobile data, and Bluetooth. This won't delete your data, but it will reset your network settings to factory defaults, which may unlock hidden carrier features.

Solution: Why the function doesn't work

Even if all conditions are met, the function may not work the first time. The most common cause is a profile conflict or cached network data. If the indicator VoWiFi If the indicator light doesn't light up, first check if you have "4G/LTE only" mode enabled, which doesn't support voice calls on this network (VoLTE). Sometimes the phone locks onto a tower with a weak signal and ignores Wi-Fi.

Another common issue is corporate networks or public Wi-Fi with browser-based authentication (Captive Portal). Until you log in on the provider's page, your phone won't have full internet access, and the call won't go through. Some routers also have settings that block certain ports required for SIP protocols, although this is rare.

List of actions to take when errors occur:

• 🔄 Restart your router and smartphone.
• ✈️ Toggle Airplane Mode on and off.
• 🗑️ Delete the saved Wi-Fi network and reconnect.
• 📲 Make sure the SIM card is not damaged and is installed correctly.

If all else fails, there may be a problem with your carrier or your account. Make sure your number isn't blocked from making outgoing calls or hasn't reached its minute limit (though incoming calls should work). It's also worth checking whether your antivirus or firewall is blocking system services on your phone.

Pricing and traffic consumption for calls over Wi-Fi

Many users are concerned that Wi-Fi calls will eat up gigabytes of their data plan. We hasten to reassure you: voice traffic in technology Voice over Wi-Fi MTS doesn't charge for internet traffic. Call minutes are deducted from your basic package, just like when calling through a cell tower.

If you have unlimited minutes, you'll also have unlimited minutes over Wi-Fi. If your minutes are used up, you'll be charged at your plan's base rate. The only caveat is that calls to emergency numbers (112, 102, 103) are always free, regardless of the connection method. However, if you're roaming internationally, the rules may differ: incoming calls are often free, but outgoing calls are charged as if they were coming from your home network (if the "Unlimited Roaming" or similar option is enabled).

It is important to note that Switching between Wi-Fi and cellular networks during a call is currently not supported.If you start a call over Wi-Fi and move out of the router's coverage area, the call will be disconnected. You'll have to redial, and then your phone will attempt to use the cellular network (if VoLTE is supported, the call may continue without being disconnected, but this depends on the specific phone model and region).

Does internet speed affect sound quality?

Yes, it does. A stable connection with a minimum of 100 kbps in both directions is required for a comfortable HD conversation. However, low ping (latency) and the absence of packet loss (jitter) are more important than maximum speed. If someone on the network starts downloading torrents or watching 4K video, connection quality may degrade.

Is it possible to make calls via Wi-Fi if the SIM card is blocked?

No. To log in to the operator's network and establish a VoWiFi connection, the SIM card must be active. Emergency calls (112) may be possible without a SIM card or with a blocked account, but this depends on the country's laws and the network's technical capabilities.

Does VoWiFi work abroad without roaming?

Yes, this is one of the best ways to save money. If you're connected to Wi-Fi at a hotel abroad, you can call Russian numbers as if you were in Russia. Just remember to turn on airplane mode first, then Wi-Fi, to ensure your phone doesn't try to connect to a foreign tower, which could lead to accidentally connecting to a roaming partner.

Why does the HD icon appear on the screen during a call?

The HD or VoLTE icon means the call is transmitted in high quality over a 4G cellular network. If Wi-Fi is active, the icon may change to a handset with a Wi-Fi symbol. This confirms that the technology is working correctly and audio is transmitted over a wide frequency range.