Modern operating conditions for mobile devices often dictate their own rules, especially in areas with unstable cellular network coverage. MTS Wi-Fi Call — is a technological solution that allows the operator's subscribers to make and receive voice calls via a wireless internet connection. This feature is indispensable in basements, country houses with thick walls, or offices where base station signals are virtually nonexistent.
The technology known as VoWiFi (Voice over Wi-Fi) is integrated directly into your smartphone's standard dialing function. You don't need to install additional apps or use messaging apps to communicate. This means you dial a regular phone number, and the MTS network automatically reroutes your voice traffic through an available Wi-Fi hotspot, providing high-quality communication where previously you only heard a dial tone or a dropped call.
The main goal of introducing this service is to improve the quality of customer service in hard-to-reach places. Switching between mobile network and Wi-Fi during a call occurs automatically and seamlessly for the user., if the device supports the appropriate standard. In this article, we'll cover in detail how the technology works, how to activate it on various devices, and answer frequently asked questions about the pricing of these connections.
How VoWiFi technology works
The technology is based on the IMS (IP Multimedia Subsystem) protocol, which allows the transmission of multimedia content, including voice, over IP networks. When you make Wi-Fi callYour voice is digitized, broken into data packets, and transmitted through the router to MTS's servers. There, the data is converted back into a voice signal and sent to the person you're talking to, whether they're on the same network or on the other side of the world.
Unlike popular messaging apps, which use their own servers and compression algorithms, VoWiFi operates at the carrier level. This ensures that your phone number remains your primary identifier. The person on the other end of the line will see your regular number, not a name from your contact book or a random ID. Furthermore, the sound quality often surpasses standard GSM calls thanks to the use of high-definition codecs.
It's important to understand that this feature requires authorization on the operator's network. Even if you're abroad, your smartphone first establishes a secure connection to MTS's infrastructure and only after access rights are confirmed does it allow the call. This ensures a high level of security. security and protection from data interception, which is critical when using open public networks in cafes or airports.
⚠️ Please note: For this technology to work properly, your router must support low ping data transfer. If your Wi-Fi is overloaded with downloads or 4K video streaming, voice quality may deteriorate.
The connection establishment process takes a fraction of a second. The smartphone constantly monitors the cellular network signal strength. As soon as it detects that the LTE/3G signal has become too weak, but reliable Wi-Fi with VoWiFi support is available, the system switches the radio mode. The user may only notice a brief change in the network icon in the status bar.
Advantages and features of use
Using Wi-Fi calling technology offers MTS subscribers a number of significant advantages that are difficult to overstate in today's urban environment. First and foremost, it allows them to stay connected in "dead zones." Concrete shopping mall structures, metal building frames, and deep basements no longer pose a barrier to communication.
The second important aspect is battery conservation. Searching for a cellular signal in poor coverage areas forces the smartphone module to operate at maximum power, which quickly drains the battery. Switching to Wi-Fi calling Reduces antenna load since the router is usually located close to the user. This extends the device's battery life in standby and call modes.
It's also worth noting its versatility. You can use your home phone as a mobile phone, even if the SIM card is installed in a smartphone in another room, as long as it's connected to the same network or has an active hotspot. This is convenient for those who work from home and don't want to carry their phone with them all the time.
Another advantage is that you don't have to change your number or habits. All features, such as call forwarding, call waiting, caller ID, and conference calling, are fully preserved. You use the same rate plans, minutes, and options as with a regular call. There are no hidden subscriptions or additional charges for the technology itself.
Device and tariff requirements
To use the service, simply having an MTS SIM card isn't enough. Your device must meet certain technical requirements. First, your smartphone must support the VoWiFi standard. Most modern models released after 2017, including flagship models, have this feature. Samsung Galaxy, iPhone (starting with the 6s model and newer), as well as devices from Xiaomi, Huawei and other manufacturers.
Secondly, your device's software must be updated to the latest version. Carriers and phone manufacturers regularly release firmware updates that add support for new networks and optimize performance with specific carriers. If you have an older phone but it supports Wi-Fi Calling, you may need to update the software to the latest available version.
Third, the SIM card must be registered with the MTS network, supporting modern standards. In some rare cases, if the SIM card is very old (issued more than 7-8 years ago), it may need to be replaced with a new one at a mobile phone store, although in most cases, simply re-registering with the network is sufficient. Your tariff plan also matters: the service is available on almost all of the operator's past and current plans, but it's best to ensure there are no blocks on your account.
☑️ Checking connection readiness
Particular attention should be paid to the router settings themselves. While in most cases these settings don't require intervention, some home internet providers may block certain ports or protocols needed to prioritize voice traffic. If you're using a corporate network or a complex firewall, you may need to configure exceptions for MTS servers.
How to enable Wi-Fi calling on iPhone
Apple device owners are lucky with the ease of setup. The iOS interface is intuitive, and activating the feature takes just a couple of minutes. Before you begin, make sure your iPhone is connected to Wi-Fi and has an MTS SIM card inserted.
The first step is to go to the main settings of the device. Find the section Cellular communications (Cellular). If you have a dual-SIM phone, select the SIM card that belongs to MTS. Then click on Wi-Fi calls (Wi-Fi Calling). Move the slider to the "On" position.
The system may request that you confirm your address for emergency services (E911). This is a standard procedure required by regulators: when calling emergency services via Wi-Fi, the operator must know your location, as GPS over Wi-Fi can be inaccurate. Please enter your current residential or registered address.
What should I do if the Wi-Fi calling option is missing?
If you don't see "Wi-Fi Calling" in your cellular settings, it means your carrier doesn't support this feature for your SIM card, or your carrier hasn't updated the settings profile. Try removing and reinserting your SIM card, then check for iOS updates in General → Software Update. Also, make sure your iPhone isn't locked to a different carrier.
After switching on, the following message will appear in the status bar (top left or right, depending on the model) next to the operator's name: Wi-FiThis indicates that the phone is ready to make internet calls. If you leave the Wi-Fi range, the phone will automatically switch to the cellular network if one is available.
⚠️ Note: If you move to another country, this feature may work differently due to roaming regulations. Make sure data roaming is enabled in your cellular settings, even if you plan to only make calls over Wi-Fi.
Setting up the feature on Android smartphones
Android devices have a more varied interface, as each manufacturer (Samsung, Xiaomi, Honor, etc.) makes its own changes to the interface. However, the logic for enabling the app remains similar. Most often, the setting is found in the menu. Settings → Connections or Network and Internet.
On smartphones Samsung the path usually looks like this: Settings → Connections → Wi-Fi calling. Here you need to activate the switch. On devices Xiaomi And Redmi look for the section SIM cards and mobile networks, select the desired SIM card and find the item Wi-Fi callingIn some versions of MIUI, this option may be hidden in the menu. Additionally.
If you can't find a setting in the menu, use the phone settings search. Enter "Wi-Fi" or "Calls" in the search bar, and the system will suggest the appropriate option. Make sure the corresponding icon is displayed in the "About phone" section or in the status bar.
Some models may require installing a special carrier companion app, although MTS strives to integrate this feature natively. Check Google Play for updates to your phone's system components. Also, ensure that the date and time settings are set to automatic, as time desynchronization can interfere with IMS network authorization.
Tariffs and roaming: how much does it cost?
One of the most important questions for subscribers is the cost of these calls. MTS positions this service as a free option. This means that a minute of call over Wi-Fi is charged exactly like a regular minute on your plan. If you have an unlimited minutes package, a call over Wi-Fi will not reduce your balance or incur any charges.
The issue of roaming requires special clarification. If you're abroad and connected to Wi-Fi, calls to Russia will be charged as incoming or outgoing international roaming calls, according to your plan. However, using Wi-Fi Calling allows you to avoid incoming call charges in some countries if the call is made to your number and you're in your home region but in a poor signal area.
It's important to remember about internet traffic. Voice traffic uses minimal data. One minute of high-quality conversation uses approximately 1-2 MB of data. If you have unlimited home internet, you don't have to worry about anything. If you share Wi-Fi from your phone or use a limited data plan, there will be some data usage, but it's negligible compared to watching videos or downloading files.
| Call type | Home region | Roaming (abroad) | Traffic consumption (approximately) |
|---|---|---|---|
| To MTS mobile phones | Free (according to tariff) | At the roaming rate | ~1.5 MB/min |
| To other Russian operators | Minutes/tariff package | At the roaming rate | ~1.5 MB/min |
| Incoming calls | For free | Depends on the country | ~1.5 MB/min |
| Emergency services | For free | Not always available | ~1.5 MB/min |
It's also worth mentioning video calls via the phone's native function (not via messaging apps). They can also be made via Wi-Fi Calling if both users support ViLTE/VoWiFi technology, but this will require more data. Always check your plan's terms for video calling.
Troubleshooting and diagnostics
Despite the technology's robustness, users may encounter difficulties. The most common issue is that the Wi-Fi Calling icon doesn't appear, even though all settings are correct. In this case, try restarting your smartphone. Refreshing your IMS network registration often helps.
The second common problem is intermittent connection or echo. This almost always indicates issues with the internet connection, not the carrier's network. Try moving closer to the router or disconnecting other devices actively downloading files. Restarting the router itself may also help.
If the feature worked but then stopped working, check if the My MTS app or your phone's system software has been updated. Sometimes, settings are reset after updates. Go to Settings again and recheck the sliders. Also, make sure your balance is sufficient, although even a negative balance is sufficient for the feature to work if incoming calls are free.
⚠️ Warning: If you use a VPN, the VoWiFi feature may not work. Security protocols often block or redirect voice traffic, resulting in connection errors. Disable your VPN before making important calls.
In rare cases, the problem may be on the operator's end due to maintenance. If all else fails, it's worth contacting MTS technical support via in-app chat or by calling the short number, after calling from a different phone number.
Reset network settings
If all else fails, try resetting your network settings. This will delete saved Wi-Fi passwords and Bluetooth settings, but it often resolves network registration issues. Go to Settings → System → Reset → Reset Network Settings.
Frequently Asked Questions (FAQ)
Will Wi-Fi Calling work if I disable mobile network in settings?
Yes, this feature is designed specifically for internet use. You can completely disable mobile data and even enable Airplane Mode, then turn on Wi-Fi only. Calls will work as long as your phone is registered to the Wi-Fi Calling network.
Can I make calls via MTS Wi-Fi while abroad, as if I were in Russia?
Technically, the call will go through, but the rate will depend on your location. If you're roaming, calls will be charged according to roaming rules, even if they're made over Wi-Fi. However, if you're calling a Russian number while abroad, it may be cheaper than a direct roaming call, but you should check your plan for exact terms.
Why does the Wi-Fi icon disappear during a call?
This could mean that the Wi-Fi signal quality has dropped below the threshold required for voice communication, and the phone has switched to the cellular network (if available). Alternatively, the router has lost its internet connection. Check the stability of your home network.
Do you need a special app for calls?
No, this feature is built into the system on modern smartphones. A separate MTS Connect app or similar apps for voice calls over Wi-Fi are not required; the standard dialer app is used.
Does this feature work on tablets?
Yes, if the tablet supports a SIM card (LTE version) and has the appropriate firmware, and if the carrier supports registering the tablet on the IMS network. On SIM-less tablets, this feature can be enabled by tethering to an iPhone (Continuity), but that's a different ecosystem feature.