Modern mobile communications are no longer just voice calls through cellular base stations. In dense urban areas or, conversely, in remote country homes, the 3G or 4G signal is often unstable or completely absent. It's in these situations that technology comes to the rescue. VoWiFi, which allows calls to be made over an internet connection rather than through cell phone towers. MTS is actively implementing this feature, allowing subscribers to stay connected even in areas where regular networks don't reach them.
Activating this feature can significantly improve communication quality, but it requires proper configuration both by your carrier and in your smartphone's menu. Many users encounter difficulties with initial activation or don't understand why the handset icon with the Wi-Fi symbol doesn't appear after enabling the feature. In this article, we'll cover all the connection steps, possible errors, and the nuances of how the technology works on various devices.
It's worth noting that switching to internet calls isn't charged separately if you're in your home region. This means minutes are deducted from your basic plan just like a regular call. However, if you're roaming, the rules may differ significantly, so keep this in mind to avoid unexpected international call charges.
What is VoWiFi technology and how does it work?
Technology Voice over Wi-Fi VoWiFi is a method for transmitting voice calls over Wi-Fi networks using the IP protocol. Unlike popular messaging apps, which require a separate app and the other party to have the same software, VoWiFi is integrated directly into your phone's standard dialing interface. For the recipient, the call process is completely familiar: you dial the number and press the call button.
A key advantage is that the connection is established through the nearest Wi-Fi access point, bypassing cellular coverage issues inside buildings. This is especially relevant for buildings with thick walls, basements, or office buildings, where the signal from base stations MTS can be shielded. The operator provides traffic encryption, so conversation security remains high.
It is important to distinguish between this technology and VoLTE. If VoLTE Since voice is transmitted over fourth-generation networks (4G/LTE), VoWiFi uses any available internet channel. Voice quality is often higher than in standard 2G/3G networks thanks to support for high-definition codecs. However, connection stability directly depends on the speed and ping of your Wi-Fi network.
Technical details of VoWiFi operation
The IMS (IP Multimedia Subsystem) protocol is used to route voice traffic. The phone creates a secure tunnel to the operator's server, allowing voice packets to be transmitted with priority over regular internet traffic, minimizing delays and interruptions.
Checking device and tariff compatibility
Before you begin setup, you need to make sure your equipment and SIM card support the required standards. Not all smartphones, even modern ones, have hardware or software support for working with networks. MTS in Wi-Fi Calling mode. This primarily applies to devices not purchased from official dealers in the Russian Federation, but imported from other countries that may have used different firmware settings.
The condition of your SIM card is also critically important. Older SIM cards Mini-SIM or Micro-SIMSIM cards used more than 5-7 years ago may not support the required encryption and authentication algorithms in the IMS network. In this case, the only solution is to replace the SIM card with a new one at a mobile phone store or through the operator's app, which is usually free or for a nominal fee.
Additionally, your tariff plan must allow this option. While MTS offers this feature on most current archived and current tariffs, it may be blocked by default on some corporate or special offers. You can check your connection status through your personal account or contact center.
Activating the service on the MTS operator's side
The first step in the setup process is enabling the service on the operator's network. Even if your phone is fully operational, the connection will not be established without permission from the provider. MTS offers several ways to activate the service, so each user can choose the most convenient service management option.
The fastest way is to use a USSD command. This is a universal method that works on any phone, even without internet access or the settings menu. Simply dial a short code, and the system will process your request instantly. However, codes may vary slightly depending on the region and license plate type, so always check official information.
An alternative and more informative method is to use the "My MTS" mobile app or your personal account on the website. Here, you can not only activate the service but also track its connection status. In the app interface, the option may be called "Wi-Fi Calling" or have a corresponding logo in the connected options section.
☑️ Pre-activation check
Setting up Wi-Fi calling on Android
Operating system interface Android The settings menu can vary significantly depending on the smartphone manufacturer and the operating system version. Samsung, Xiaomi, Honor, and other brands implement the settings menu differently, but the general principle remains the same. You'll need to find the section responsible for mobile network or connections.
On most devices, the setup process looks like this: go to "Settings," then select "Connections" or "SIM cards & mobile networks." Within this menu, look for "Wi-Fi Calling." Once in the menu, toggle the slider to the on position. In some cases, the system may ask you to confirm your address for emergency services.
For smartphone owners Samsung Often an additional step is required: in the dialing menu, you need to tap the three dots (menu) and select "Settings", where the switch you are looking for is located. On devices Xiaomi And Redmi This feature may be hidden in the "Phone app" -> "Carrier settings" section. If the switch is grayed out, it usually means the SIM card isn't recognized as supported, or the service isn't activated on the MTS side.
⚠️ Attention: On some Android models, enabling this feature may require you to enter your address for the 112 service. Please ensure you enter your actual address, as the operator may share these coordinates with emergency services when calling.
Once enabled, a corresponding icon should appear in your smartphone's status bar. It may look like a phone handset with the word "Wi-Fi" or a VoWiFi symbol. If the icon appears but calls aren't going through, try restarting your device or switching to airplane mode.
Instructions for iPhone (iOS) owners
For smartphone users Apple We're fortunate to have a more unified interface. VoWiFi setup on iPhone typically occurs automatically after updating carrier settings, but you can check and enable it manually if needed. The menu logic is consistent across all models, starting with the iPhone 6 and later, running the latest versions of iOS.
To activate, open "Settings" and go to "Cellular." Select "Wi-Fi Calling" and toggle "Wi-Fi Calling on This iPhone." The system may prompt you to share your location data with your carrier—this is standard procedure for emergency services, and you must confirm it.
If you have two SIM cards installed in your phone (Dual SIM mode), the settings are applied individually to each number. You can enable the feature only for the primary MTS SIM card, leaving the second one in normal mode, or activate it for both. This menu also includes the "Add Internet Phone" option, which allows you to make calls from your iPad or Mac via your iPhone.
| Parameter | Android | iOS (iPhone) |
|---|---|---|
| Path to the menu | Settings -> Connections / Network | Settings -> Cellular |
| Automation | Often requires manual activation | Often turns on automatically |
| Status icon | Tube + Wi-Fi / VoWiFi | MTS Wi-Fi (top left) |
| Emergency services | Request address on first launch | Request for data confirmation |
Troubleshooting connection issues and errors
Despite the simplicity of setup, users often encounter situations where the feature is advertised but doesn't work. One of the most common causes is network conflicts. If the phone "sees" a weak cellular network, it may prioritize it, ignoring Wi-Fi. In the mobile network settings, you can try setting "4G/LTE Only" or temporarily enabling airplane mode to force the phone to re-register with the network.
Another common issue is roaming. If you're in another region or country, the feature may not work, even if you're connected to your home Wi-Fi. Carriers often block VoWiFi in international roaming due to billing issues. In such cases, a message may appear on your screen stating that calls cannot be made.
It's also worth paying attention to your router settings. Some corporate or public Wi-Fi networks block ports required for voice traffic or use complex authorization systems (captive portals) that prevent the phone from fully accessing the IMS network. In this case, switching to mobile data (if available) or changing the access point will resolve the issue.
⚠️ Attention: When calling emergency services (112, 102, 103) via Wi-Fi, the operator may not be able to determine your exact location if the phone's settings contain an incorrect address or if you are not at your registered address. Always confirm your location with the dispatcher by voice.
Comparison of VoWiFi, VoLTE, and regular calls
Understanding the differences between these technologies helps you choose the optimal use case. Regular calls (2G/3G) use circuit-switched (CS) channels, which guarantee voice priority but result in poor audio quality and long connection times. VoLTE Transmits voice as data over 4G networks, providing fast connections and HD sound, but requires LTE coverage.
VoWiFi It uses any available internet connection. This makes the technology indispensable in cellular dead zones. However, unlike a cellular network, where voice priority is controlled by the operator, on Wi-Fi networks, your call may compete for bandwidth with file downloads or video streaming, sometimes resulting in audio artifacts.
In terms of battery life, VoWiFi can consume more power if the Wi-Fi signal is weak, as the phone's module operates at increased power to maintain the connection. However, with a stable home router, the difference in battery life compared to normal standby mode is minimal.
Impact on battery
Using Wi-Fi Calling in an area with poor cellular signal (1-2 bars) often saves battery life, since the phone does not need to constantly strengthen the signal to search for a cell tower.
Will I be charged for minutes spent talking on Wi-Fi?
No, if you're in your home region. Minutes are deducted from your plan just like regular calls. The exception is international roaming, where special rates may apply.
Can I use VoWiFi if my router has a MAC address filter?
Yes, it is possible. This technology doesn't require opening special ports or forwarding traffic. The phone automatically establishes a secure connection to the operator's servers, so router settings usually don't affect operation as long as there's internet access.
What should I do if the VoWiFi icon disappears after updating iOS or Android?
Try resetting your network settings (not resetting everything, but just resetting your network settings). This will delete saved Wi-Fi passwords and Bluetooth settings, but it often restores your carrier profile and restores the icon.
Does this feature work if the router's internet connection is limited by time or traffic?
The feature will work as long as you have internet access. However, voice traffic is quite economical (about 1-2 MB per minute in HD), so even limited plans allow you to stay connected for a long time.