Modern mobile operators, including MTS, are actively implementing technologies that allow subscribers to stay connected even in areas with poor cellular signal. One such option is VoWiFi, or Wi-Fi calling. For smartphone owners Samsung This feature is often a revelation as it allows you to make and receive calls over your home or office wireless network using the same phone number.
Many users encounter confusing notifications in their call log or device status bar that mention a Wi-Fi connection. This isn't a bug or a third-party app, but rather the built-in Voice over IP (VoIP) technology. Unlike traditional messaging apps, it doesn't require installing additional software or registering a new account.
MTS supports this technology on most modern devices, making it accessible to a wide range of subscribers. Understanding how it works Wi-Fi Calling It will help you save battery power in areas with poor reception and improve connection quality in rooms with thick walls where base station signals simply cannot penetrate.
What is VoWiFi and how does it work on Samsung smartphones?
Technology Voice over Wi-Fi (VoWiFi) is a way to transmit voice calls over an internet connection rather than traditional GSM or LTE cellular networks. When you're at home and your smartphone Samsung Connected to a router, voice traffic is converted into digital data packets and transmitted through the MTS operator's gateways to the general telephone network.
The main advantage is the transparency of the process for the user. You don't need to dial a number through WhatsApp or Telegram. You simply open the standard dialer, select a contact from your phone book, and press the call button. The system automatically detects whether the cellular signal is weak but there is an active Wi-Fi connection, and automatically routes the call over the internet.
Connection quality in this case directly depends on the speed and stability of your home internet connection. If your provider provides a stable ping and sufficient bandwidth, your caller's voice will sound crystal clear, often better than with a standard GSM connection. However, it's important to keep in mind that this technology requires support from both the device itself and the carrier's firmware.
⚠️ Please note: For this feature to work, your MTS tariff plan must support VoWiFi. On some archived tariffs, the service may be unavailable or require activation.
From a technical point of view, a smartphone Samsung Creates a secure tunnel to MTS servers. This ensures that your conversation won't be intercepted by third parties, even if you're using a public Wi-Fi network in a cafe or shopping mall. The encryption protocols used here are similar to those used in banking apps.
Differences between VoWiFi technology, VoLTE, and instant messaging
Users often confuse Wi-Fi calling with technology VoLTE (Voice over LTE). Although both technologies use packet data (IP), there is a significant difference. VoLTE operates exclusively over the operator's 4G/LTE network, while VoWiFi uses any available wireless connection, regardless of the internet provider.
Unlike messaging apps, where both parties must have the app installed and an account, VoWiFi lets you call any number, including landlines and other carriers. For you, it's a regular call, billed according to your minute plan, rather than using up your shared data pool.
Let's look at the main differences in a table for clarity:
| Parameter | VoWiFi (Wi-Fi Calling) | VoLTE (4G Calling) | Messengers (WhatsApp, Viber) |
|---|---|---|---|
| Communication channel | Wi-Fi router | 4G/LTE network | Internet (Wi-Fi or mobile) |
| Tariffs | According to the operator's minutes package | According to the operator's minutes package | Traffic consumption (or free) |
| Requirements for the interlocutor | Any phone | Any phone | You need an app and internet access. |
| Sound quality | HD (depending on the router) | HD (depending on tower) | Depends on network speed |
Another important aspect is roaming. When abroad, connecting to a local Wi-Fi network and making a VoWiFi call to a Russian number is often treated by the operator as incoming/outgoing calls within the home region, allowing you to avoid international roaming charges. However, MTS terms and conditions are subject to change, so it's best to check the current rules in your personal account before traveling.
How to check if a feature is supported on a Samsung device
Not all smartphone models Samsung VoWiFi is supported out of the box, even if your carrier offers the service. First, make sure your device is certified to work with MTS networks with this feature. Typically, these are Galaxy S, A, and Note series models released in the last three to four years.
Checking starts with the software version. Make sure your smartphone is updated to the latest available version. Carriers often add support for new features through firmware or configuration file updates. Go to Settings → Software Update → Download and Installto exclude this factor.
It's also important to have a new SIM card. If your SIM card has been in use for many years and is a non-standard size (likely cut with scissors), it may not work correctly with modern protocols. In this case, we recommend replacing your SIM card free of charge at an MTS store with a USIM-compatible one.
- 📱 Open the default Phone app on your Samsung.
- ⚙️ Go to the three-dot menu and select "Settings."
- 🔍 Look for the “Wi-Fi Calling” option.
- 📶 Check the status bar: when activated, a corresponding icon should appear there.
If Wi-Fi calling isn't available in your phone's settings menu, it doesn't always mean it's unsupported. Sometimes the feature is hidden in the engineering menu or requires activation via a special USSD code sent by your carrier upon your first connection attempt within a coverage area.
Hidden codes for diagnostics
In some cases, you can use codes in the dialer app to check the status of services. For example, dialing ##4636## Opens the testing menu, where you'll find a VoWiFi toggle switch under "Phone Information." Be careful: changing settings in this menu without understanding the process can result in loss of connection.
Step-by-step instructions: enabling VoWiFi on Samsung
The process of activating the function on smartphones Samsung The interface is standardized, but may vary slightly depending on the version of the One UI shell. Before you begin, make sure your smartphone is connected to Wi-Fi and has an MTS SIM card installed.
The first step is to open the device's main settings. Swipe down from the top to open the notification panel and tap the gear icon. In the menu that opens, find the "Connections" section. This is where you'll find the main network settings.
Under the "Connections" section, find "Wi-Fi Calling." If you don't see it right away, try searching for "Wi-Fi" in the settings at the top of the screen. Toggle the slider to the on position. You may be asked to confirm sending your location data for emergency calls—this is a regulatory requirement.
☑️ Activation algorithm
Once turned on, a handset icon with the word "Wi-Fi" or a wireless network symbol should appear at the top of the screen next to the signal strength indicator. This indicates that the device has successfully registered with the MTS VoWiFi network.
In some cases, you may need to configure your preferred network type. Go to Settings → Connections → Mobile network → Network mode and select 5G/3G/2G (auto)Sometimes, forced switching to "4G Only" mode helps to quickly activate the IMS protocols required for voice services.
Solution: Why Wi-Fi Calling Isn't Working
Even with proper configuration, users may encounter situations where the feature doesn't activate or calls are dropped. One common cause is blocking required ports at the router level. Some home internet providers or router security settings may prevent SIP traffic.
The problem may also be due to a software version conflict. If your smartphone Samsung If the device was purchased abroad (version for another region), its firmware may be missing config files for Russian operators. In this case, flashing the device to the regional version (CSC) using the Odin program can help, but this requires caution.
⚠️ Warning: Reflashing your smartphone yourself may void your warranty and brick your device. If you are unsure, contact an authorized service center.
Another important point is roaming. To use VoWiFi abroad, the "Data Roaming" option must be enabled in your phone's settings, even if you're making calls over Wi-Fi. Without this permission, your phone may not register with the MTS partner network.
- 🚫 Check if Do Not Disturb or Airplane mode is enabled (in the latter case, Wi-Fi must be turned on manually).
- 🔄 Restart your smartphone after enabling the feature in settings.
- 📡 Make sure your Wi-Fi signal is stable (at least 2-3 bars).
- 💳 Check your account balance and ensure there are no service blocks.
If all else fails, try deleting the Wi-Fi network profile and reconnecting, entering the password. Sometimes resetting the network settings helps: Settings → General Settings → Reset → Reset Network SettingsThis action will delete saved Wi-Fi passwords and Bluetooth settings, but will reset network settings to factory defaults.
Impact on connection quality and traffic consumption
Many subscribers fear that Wi-Fi calls will quickly eat up all their internet data. We hasten to reassure you: VoWiFi voice traffic uses a minimal amount of data. One minute of conversation takes approximately 0.5 to 1.5 MB of data, depending on the codec. By comparison, a minute of high-quality video call can require up to 10-15 MB.
MTS typically doesn't charge this traffic separately if it's included in your bundled minutes. However, if your bundled minutes are completely exhausted, the call may be charged at the base rate, and the traffic may be drawn from the shared pool or charged separately if you haven't activated an unlimited plan.
The sound quality when using VoWiFi often surpasses standard voice quality. This technology enables the use of wideband codecs (HD Voice), which transmit a wider frequency range of voices. This makes speech more natural and intelligible, especially in noisy environments.
It's important to understand that when switching between Wi-Fi and a cellular network (for example, if you leave the house during a call), the call may be dropped or revert to a regular GSM connection. Handover technology (call transfer between networks) doesn't work on all devices and depends on the support of MTS base stations in your area.
Do I need to pay separately to connect to the VoWiFi service?
MTS generally doesn't charge a subscription fee for using the technology. However, in some regions or on certain plans, you may need to activate the free option through your personal account or a USSD command. For more information, please visit the "My MTS" app.
Can I use VoWiFi if I have an ad blocker on my phone?
Aggressive ad blockers or device-wide VPN services can block connections to the operator's servers required for VoWiFi authorization. Try disabling them during the call or adding MTS servers to the exceptions list.
Does Wi-Fi Calling work if the router distributes Internet from a 3G/4G modem?
Technically, this is possible, but connection quality will depend on the stability of the modem's connection. Furthermore, some home internet providers may block ports required for VoWiFi, so results are not guaranteed.
Why does the VoWiFi icon appear and disappear?
This may indicate an unstable Wi-Fi signal or intermittent loss of connection with the operator's IMS servers. This behavior is also typical when the battery is low, when the system attempts to conserve power by disabling background network activity.
Will VoWiFi work on a Samsung push-button phone?
In most cases, no. The technology requires support from the operating system and modem, which is primarily implemented in Android smartphones. Older push-button models, even from Samsung, usually lack the necessary software.