The situation when the mobile network disappears indoors, but the wireless Internet works stably, is familiar to every smartphone owner. In such conditions, missed important calls become commonplace, and outgoing calls are interrupted before they even begin. Fortunately, modern technologies make it possible to solve this problem without purchasing additional equipment or complex manipulations with the operator.
Technology VoWiFi (Voice over Wi-Fi) from the MTS operator allows you to use any available wireless Internet to make voice calls and send SMS. This means that you will be able to receive calls even in a deep basement, in a country house with poor coverage, or in a building with thick walls, where a regular GSM/4G signal simply does not penetrate. For Android smartphone users, this process is as automated as possible and often requires only a couple of clicks in the settings.
In this article we will look in detail at how to activate the Wi-Fi calling function on devices running the Android operating system. We will look at the hardware requirements, a step-by-step algorithm for enabling the service, as well as configuration nuances for various phone models. Understanding these processes will help you stay connected in any conditions, taking advantage of modern communication infrastructure.
⚠️ Attention: The settings menu interface may differ depending on the version of the manufacturer's shell (MIUI, One UI, ColorOS, etc.) and the version of Android. If you do not find the item described, try using the search in your phone settings.
What is VoWiFi and how it works
The technology VoWiFi is the transmission of voice traffic via IP, similar to how instant messengers work, but with integration into a standard phone book and dialer. Unlike calls through applications like WhatsApp or Telegram, calls through Wi-Fi Calling do not require the installation of separate software or the presence of a contact with the interlocutor. For the caller and the recipient, the process looks like a normal conversation, the signal simply goes not through a cellular base station, but through an Internet access point.
The main advantage is the quality of communication and saving battery power. When a smartphone is in an area with a weak cellular signal, it constantly tries to find a tower, wasting energy and heating up. Switching to Wi-Fi Calling solves this problem, since the wireless network is usually more stable indoors. In addition, MTS does not charge additional fees for using this technology - minutes are spent according to your tariff plan, as during a normal conversation.
It is important to understand the difference between VoWiFi and VoLTE. If VoLTE transmits voice over fourth generation networks (4G), then VoWiFi uses any Internet connection. However, both standards require support from the operator and the device itself. MTS is actively developing this infrastructure, providing coverage where the radio signal is powerless.
VoWiFi allows you to make regular voice calls via an Internet channel, saving the number and tariff, but requiring support from the smartphone and operator.
Checking the compatibility of the device and SIM card
Before Before you start setting up, you need to make sure that your equipment is technically ready to work with the new function. Not all smartphone models released several years ago support the standard IMS (IP Multimedia Subsystem), which is necessary for implementing voice calls over IP networks. Software also plays an important role: the firmware must be up-to-date and certified to work with Russian operators.
The second critical point is the status of your SIM card and tariff. The service must be available in your region and connected on the operator's side. Old SIM cards from many years ago may require replacement as they may not support the required encryption and authorization protocols. You can check compatibility through your personal account or a special USSD command.
Below is a table with the basic requirements for successful activation:
| Parameter | Prerequisite | Where to check |
|---|---|---|
| Operator | MTS (active SIM) | Network settings |
| Tariff | VoWiFi support | Personal account / *111# |
| Smartphone | IMS / VoWiFi support | Model specifications |
| Firmware | Current Android version | Settings → About phone |
If your smartphone was officially purchased in Russia, the likelihood of supporting the MTS function is very high. For devices imported from abroad (Chinese versions of global brands or models without NFC for the Russian Federation), support may not be available at the software level, even if the hardware allows it.
Activation of the service on the side of the MTS operator
The first step before setting up the phone is to connect the service itself to the operator's network. MTS provides several activation methods so that each user can choose the most convenient one. Most often, the service is free to sign up, but before you start using it, you should make sure that there are no restrictions on your tariff plan.
The fastest way is to use the USSD command. You need to open the Phone application and dial the short code. After dialing and pressing the call button, you will receive an SMS notification of successful connection or refusal indicating the reason.
*111*878#Alternative methods include using the My MTS mobile application or your personal account on the website. In the services section there is often a "Communication" or "Internet" category where you can find a toggle for "Wi-Fi Calling." Activation can also be done through the chatbot in the application by simply writing the phrase “Connect VoWiFi.”
☑️ Check before connecting
⚠️ Attention: After connecting the service on the operator’s side, changes may not take effect immediately. It is recommended to reboot your smartphone 1-2 minutes after receiving a confirmation SMS.
Setting up calls via Wi-Fi on Android
After the service is activated on the MTS side, you must enable the corresponding mode in the smartphone itself. The algorithm of actions may differ slightly depending on the manufacturer, but the general logic remains the same for the entire ecosystem Android. Usually the setting is located in the mobile networks section.
Consider a universal path that is suitable for most devices (Samsung, Xiaomi, Realme, Honor):
- 📱 Open
Settingsyour smartphone. - 📡 Go to the section
ConnectionsorSIM cards and mobile networks. - 🔍 Find the item Wi-Fi calls (or Wi-Fi Calling).
- ✅ Activate the switch to the "On" position.
In some cases, for example, on Samsung smartphones, the path may look different: Settings → Connections → Wi-Fi calling. On Xiaomi and Redmi devices, look in the menu: Settings → SIM cards and mobile networks → Select MTS SIM card → Wi-Fi calling. If you do not see this item, it may be hidden in the additional menu "More" or "Advanced".
What to do if there is no item in the menu?
If you are sure that the phone supports the technology and the service is connected, but there is no item in the menu, try resetting the network settings. Go to Settings → System → Reset → Reset Wi-Fi, mobile data and Bluetooth settings. This will not delete your personal data, but will return the network settings to factory settings.
After turning on, a special icon should appear in the status bar (where the signal level and battery are). Usually this is an image of a handset with Wi-Fi symbols or an inscription Wi-Fi Call. This indicates that the phone is ready to make calls via a wireless network.
Network priority and smartphone behavior
One of the important settings is determining the priority of networks. The smartphone needs to understand when it needs to use the cellular network and when to switch to Wi-Fi for calls. By default, most devices are set to auto-select, which is the optimal scenario for most users.
There are often three behavior options available in the VoWiFi settings menu:
- 📶 Preferred mobile network: The phone will try to use cellular even when the signal is weak, switching to Wi-Fi only when GSM is completely lost.
- 📶 Wi-Fi is preferred: If there is a wireless network, calls will always go through it, which saves battery power in areas of poor reception.
- 📶 Wi-Fi only: Calls are only possible when connected to a wireless network. In this mode, when you leave the Wi-Fi zone, the call will be interrupted.
For everyday use, it is recommended to select the “Wi-Fi Preferred” or “Automatic” mode. This will ensure the best quality of communication indoors and seamless switching (without interrupting beeps) when going outside, if the operator supports the technology Handover (switching between networks during a conversation).
If you often visit places with overloaded Wi-Fi (shopping centers, train stations), temporarily switch the priority to "Mobile network" to avoid interference and robotic voice interlocutor.
Solving common problems and errors
Despite the ease of setup, users may encounter difficulties. The most common problem is that the VoWiFi icon appears, but calls do not go through or the quality of the connection is extremely low. This is often due to the settings of the router or the Internet provider, which blocks certain ports or types of traffic.
If you see the icon, but the call is dropped:
- 🔄 Restart the router and smartphone.
- 🔒 Check if the mode is set on the router "Guest network" for your connection (it often limits functionality).
- 📡 Make sure that the Wi-Fi signal is stable (at least 2 bars).
Another common situation is that the icon disappears when you start a conversation. This may mean that the smartphone is trying to switch to 2G/3G for voice communication because VoWiFi could not install correctly. In this case, check whether the mode 4G/LTE is enabled in the mobile network settings and whether the "Use VoLTE" checkbox is there, since these technologies are often connected.
⚠️ Attention: Calls to emergency services (112, 102, 103) via Wi-Fi may not determine your location. The operator sees the address of the access point, not your coordinates. In critical situations, it is better to use a cellular network.
It is also worth considering that some corporate Wi-Fi networks in offices or public places can block voice traffic to save bandwidth. In such cases, using mobile data (distribution) or searching for an alternative access point will help.
Frequently asked questions (FAQ)
Does MTS charge an additional fee per minute of conversation via Wi-Fi?
No, charging occurs according to your main tariff plan. If you have a package of minutes, they will be used up. If the minutes are over - at the rate per minute. There is also no roaming for using Wi-Fi Calling within Russia.
Is it possible to call via MTS Wi-Fi while abroad?
Yes, technically this is possible. However, it is important to remember: if you call a Russian number while abroad, this may be considered international roaming, even if the call is made over Wi-Fi. Check roaming conditions with your operator before traveling.
Why is the VoWiFi icon lit, but the other party can’t hear me?
This may be due to the microphone settings in a particular application or a noise reduction conflict. Try disabling and enabling the "Wi-Fi calling" mode in the settings, and also check the permissions for the "Phone" application.
Does this function work if Wi-Fi is distributed to a smartphone (modem mode)?
No, in modem mode (Internet distribution) the VoWiFi function on the distributing device itself usually does not work or does not work correctly, since the channel is busy transmitting data to other devices. You can receive calls, but the quality may suffer.
Do you need to keep the screen on for VoWiFi to work?
No, the function works in the background. However, if the phone goes into deep sleep (power saving) mode, the Wi-Fi connection may be dropped to save power, causing incoming messages to be missed. Add a support number or important contacts to energy saving exceptions.