The problem of unstable cellular signal in buildings with thick walls or in remote areas is familiar to many subscribers. Mobile internet may work fine, but voice calls are dropped or not connected at all. VoWiFi (Voice over Wi-Fi) from MTS allows you to use a wireless network to transmit high-quality voice, bypassing the limitations of cell towers.
The introduction of this feature has become a real lifesaver for those who work in shielded offices or live in new buildings where the LTE signal hasn't yet reached the upper floors. Using the service doesn't require complex routers or specialized software—it's enough smartphone With standard support and an active option in your personal account. Below, we'll cover all the details of the connection.
The main advantage of this technology is that calls are billed according to your basic minute plan, rather than being treated as internet traffic. This means you can talk for hours within range of your home router without worrying about running out of data. The sound quality often surpasses standard voice calls thanks to high-resolution codecs.
What is VoWiFi and how does it work with MTS?
Technology VoWiFi Voice over IP (VOIP) is the transmission of voice traffic over IP protocols in a Wi-Fi network. Unlike messaging apps, where calls are routed through the app server, it uses a native phone book and a standard dialing interface. MTS integrated this feature directly into its IMS (IP Multimedia Subsystem) network.
When you dial a number, smartphone Automatically detects the availability of a cellular network. If the 4G/3G signal is weak or absent, but Wi-Fi is available, the device switches voice traffic to the wireless network. For the person on the other end of the line, this process is completely transparent—they simply hear your voice.
It's important to understand that this feature requires support from three components: the operator, the tariff plan, and the device itself. MTS is actively expanding its VoWiFi coverage, but in some regions or on older tariffs, the feature may not be available by default. It's also critical that router provided a stable connection with low latency (ping).
⚠️ Attention: When moving from a Wi-Fi coverage area to a strong cellular network, a call can be transferred back to the base station (handover). However, the reverse process (from a network to Wi-Fi during a call) is not supported by all phone models.
Internet speed for calls is minimal—only about 100 kbps—but connection stability is key. If your home internet connection frequently drops or has a high ping, call quality may deteriorate, with artifacts or interruptions.
Device and tariff requirements
Before you begin setup, you must ensure that your equipment meets the operator's technical requirements. Not all models smartphonesEven modern devices have software support for VoWiFi for specific operators. The list of supported devices is constantly updated.
First, check your plan. The "Wi-Fi Calling" service may not be available on archived plans or corporate plans with special terms. You also need to have 4G (LTE) service activated on your SIM card, as VoWiFi often works in conjunction with voice calls over LTE (VoLTE).
An MTS ID account is required. This is a single account used for authorization in various company services. Without MTS ID registration, activation of the feature on the operator's end will be impossible, even if all the switches on the phone are enabled.
List of popular supported models
Apple iPhone 6s and newer (iOS 12+), Samsung Galaxy S7 and newer, Xiaomi (most models with MIUI 10+), Huawei and Honor (pre-sanctions models and new ones with GMS).
Pay special attention to the software. Make sure your device is running the latest available operating system version. Manufacturers often add support for new VoWiFi operators through firmware updates.
Activation of the service in your personal account and via USSD
The first step to setting up the service is enabling it with your carrier. This can be done in several ways, without requiring any complicated phone manipulation. The fastest method is using a USSD command, which works even without internet access.
Type the command on your phone keypad *111*1478# and press the call button. You'll receive a reply SMS message confirming Wi-Fi Calling activation. If the code doesn't work, your plan may not support this feature.
A more visual method is to use the "My MTS" mobile app. Go to the "Services" section or search for "Wi-Fi Calling" in the app. The switch should be green. You can do the same in your personal account on the official website.
☑️ Check before setup
After activation by the operator, changes may take several minutes to take effect. During this time, it is recommended to reboot the device so that it re-registers with the network and receives the updated profile settings.
Setting up VoWiFi on Android smartphones
The process of enabling the feature on devices with the operating system Android The process may vary depending on the manufacturer and shell version. The logic is the same, but the menu names may vary. In most cases, the path is through the main network settings.
Open the menu Settings and find the section Connections or Network and Internet. Select an item Mobile networkThe switch should be displayed here. Wi-Fi calling (or VoWiFi). Activate it.
On some models, for example Samsung or Xiaomi, after turning on the switch, you may need to select a mode. The options are "Wi-Fi only" (which ignores the cellular network for calls) or "Wi-Fi preferred." Choose the option that works best for you.
If you can't find the switch in the standard menu, try searching for "Wi-Fi" in the settings search. The system will often prompt you to find the option you need. Also, make sure 4G/LTE is enabled in your mobile network settings.
⚠️ Attention: Xiaomi and Redmi smartphones may require geolocation to be enabled for proper operation. Without it, the system will not be able to determine your location to transmit coordinates to emergency services (E911), and the feature may not activate.
After successful setup, a special icon should appear at the top of the screen, next to the Wi-Fi signal strength. Typically, this is an image of a phone handset with a Wi-Fi symbol or the words "MTS Wi-Fi."
Instructions for iPhone (iOS) owners
To the owners iPhone You're luckier: the setup interface is the same for all models, starting with the iPhone 6s. Apple strictly controls the implementation of carrier features, so the process is as simplified and unified as possible.
Go to Settings -> Cellular communications. Find the item Wi-Fi callingToggle the switch to the on position. The system may ask you to confirm your address for emergency services—this is a standard registration procedure.
Next, select "Prefer Wi-Fi." This will force your phone to use the wireless network for calls even when the cellular signal is weak. If you often find yourself in dead zones, this mode will be most effective.
It's important to note that this feature works most reliably on iPhones, as it doesn't require extensive firmware customization, as is common on Android. Simply having support from MTS is sufficient.
Indicator compatibility and status table
Understanding the various indicators on the screen helps quickly diagnose the connection status. Below is a table explaining the main VoWiFi statuses on MTS subscriber devices.
| On-screen indicator | Meaning | Actions |
|---|---|---|
| MTS Wi-Fi / Wi-Fi Calling | The service is active, the call will go through Wi-Fi | You don't need to do anything, everything works. |
| 4G/LTE (no Wi-Fi icon) | Cellular network is in use, VoWiFi is not active | Check your phone settings and service activation |
| The icon is crossed out | Error registering with IMS network | Restart your phone and check your MTS ID. |
| Wi-Fi icon only | Only the internet works, voice is not available | Make sure the "Calls" option is enabled. |
If the lights are behaving strangely (for example, constantly blinking or disappearing during a call), this may indicate a problem with the router. Try rebooting the router or moving closer to the access point.
Common problems and solutions
Despite the simplicity of the technology, users can encounter difficulties. One of the most common issues is the absence of the VoWiFi icon after following all the instructions. Often, the cause lies in the operator profile.
Go to your mobile network settings and find "Carriers." Try selecting your carrier manually by finding MTS in the list, then change the selection back to "Auto." This will update your network settings.
Another common issue is the inability to make calls when Wi-Fi is enabled. In this case, the phone may be trying to use a weak cellular signal instead of a stable Wi-Fi connection. Try temporarily disabling mobile data or switching to "Wi-Fi only" mode in the call settings.
⚠️ Attention: Settings interfaces and terms of service are subject to change. If standard methods don't help, check the current requirements for your phone model on the official support website or contact a carrier via live chat.
It's also worth checking whether your router or antivirus software is blocking ports required for SIP protocols, although this is rarely necessary for standard VoWiFi. Usually, simply rebooting your smartphone after making any changes to the settings is sufficient.
Call security and pricing
Many users fear that Wi-Fi calls will cost more or be counted as data traffic. We're here to reassure you: MTS charges these calls the same as regular voice calls under your plan. Minutes are used from your basic package.
In terms of security, the connection between your phone and the carrier's gateways is encrypted. However, the level of protection also depends on the security of your home Wi-Fi network. It is recommended to use an encryption protocol. WPA2 or WPA3 on the router and set a complex password.
When calling from abroad (while roaming), the rules may differ. Incoming calls via Wi-Fi to an MTS number are generally free (if incoming calls are free on your plan), while outgoing calls are charged according to roaming conditions, as if you were calling from within Russia.
FAQ: Frequently Asked Questions
Do you charge for calls over Wi-Fi?
No, there is no separate charge for the technology. Minutes are used from your main MTS plan just like regular calls. Once the minutes run out, you'll be billed according to your plan.
Do you need mobile internet to make calls?
No, VoWiFi only requires a Wi-Fi connection. Mobile data (3G/4G) can be disabled, but the call will still work as long as the service is active and there's a Wi-Fi signal.
Why did the VoWiFi icon disappear during a call?
This may mean the phone has lost its connection to the Wi-Fi router or the signal has become too weak for voice communication, and the device has switched to the cellular network. Check the Wi-Fi signal strength.
Does the service work if I am abroad?
Yes, technically, you can make calls anywhere there's Wi-Fi. However, the rate will depend on your roaming plan. Incoming calls are often free, while outgoing calls are subject to roaming rates.
Is it possible to call 112 via Wi-Fi?
Yes, emergency calls (112, 102, 103) are supported via VoWiFi. However, for the dispatcher to determine your location, it is critical that geolocation be enabled on your phone.