Modern life dictates its own rules, and stable voice communication is becoming critical not only in the city center but also in remote areas. It often happens that the indoor cellular network is extremely unstable, creating "dead zones," while the home internet runs at maximum speed. It's precisely for these situations that MTS has implemented technology. Voice over Wi-Fi, which allows you to make voice calls over a wireless connection.
Activating this feature turns your smartphone into a fully-functional communication tool, even in areas where a regular GSM or LTE signal is completely absent. You'll no longer have to run to the balcony or go to the window to hear your conversation partner. VoWiFi Provides high-quality sound comparable to HD voice and allows you to seamlessly switch between networks during a call.
In this article, we'll detail all the nuances of connecting to the service, review device and plan requirements, and address common setup issues. You'll learn how to properly activate the feature on iPhone And Android, and what to do if the desired option does not appear in the menu.
What is VoWiFi and how does it work?
Technology VoWiFi (Voice over Wi-Fi) is an extension of the standard's functionality. VoLTE, but with voice traffic transmitted via Wi-Fi internet channels instead of cell towers. This means the voice data packet is routed through the nearest internet access point and then into the MTS network. This process is completely transparent for the subscriber.
The main advantage is that the call is made using your regular phone number. You don't need to install third-party apps like Skype or Viber, search for contacts in your messenger's address book, or explain to the other person which app you're currently using. Everything happens through your smartphone's standard dialer interface.
It is important to understand that VoWiFi — This isn't just an analogue of IP telephony, but a fully-fledged replacement for the voice channel. The operator identifies your device and plan, verifies your call rights, and connects subscribers. Connection quality in this case directly depends on the bandwidth and stability of your Wi-Fi router.
Technically, the process works like this: your phone encrypts the voice signal, transmits it to the router, and then the data travels through the internet provider to MTS servers, where it is decoded and connected to the other party. The entire process takes milliseconds, so there's virtually no delay in the conversation.
MTS device and tariff requirements
Before you begin setting up, you need to make sure your hardware and data plan support this technology. Not all older smartphone models and not all archived data plans are compatible. Voice over Wi-FiFirst of all, the device must support the standard. VoLTE, since VoWiFi is its logical continuation.
The list of supported devices is constantly expanding, but basically these are all models iPhone, starting with version 5c (iOS 12 and above), and most modern smartphones based on Android (Samsung, Xiaomi, Huawei, Honor and others) released after 2016. The operating system must be updated to the current version.
List of rare models
Some push-button phones and very old smartphones running Android versions below 6.0 may not have a built-in module for working with the operator's IMS profile, which makes it impossible to use VoWiFi even if Wi-Fi is available.
Regarding tariff plans, MTS offers Wi-Fi calling for most current archived and line plans. However, if you use corporate communications or specific options, there may be some caveats. The service is also not available to subscribers with blocked voice access.
A mandatory requirement is that the function must be enabled. VoLTE in the subscriber profile. These two services are often linked through the operator's network settings. You can check the status through your personal account or with a USSD command, but the easiest way is to try activating the switch in your phone settings.
Compatibility check and preparation
The first step before setting up should be a thorough diagnosis of the current network and device status. Don't dive into deep menus if the basic requirements aren't met. Make sure the SIM card isn't too old (preferably no more than 5-7 years old) and has no physical damage to the contacts.
The second important factor is region. MTS's VoWiFi service works throughout Russia, but restrictions may apply in some remote locations or when roaming abroad. When roaming internationally, Wi-Fi calls are often charged as incoming and outgoing calls in your home region, which is a huge advantage for travelers.
To prepare, follow these steps:
- 📱 Update your smartphone's operating system to the latest available version.
- 🔄 Make sure that the cellular network mode is enabled in the settings 4G/LTE.
- 📡 Check the stability of your Wi-Fi: the speed should be at least 1 Mbps for incoming calls and 2 Mbps for outgoing calls.
- 💳 Make sure you have sufficient funds in your account balance or that you have activated a plan with a monthly fee.
It's also worth checking that your phone isn't in Airplane mode with Wi-Fi disabled, as this completely disables the communication modules. If you have a dual-SIM phone, you'll need to apply the settings separately for each SIM card if both are from MTS and you plan to use VoWiFi on both.
If the feature still doesn't appear after all the checks, your phone may simply not be certified by the operator to work with this feature on the MTS network, even if it technically supports the standard. In this case, the only solution is to replace the device or contact support to clarify the list of compatible models.
Instructions: Activation on iPhone (iOS)
For smartphone owners Apple You're the luckiest of all, as the feature's integration into iOS is extremely simple and intuitive. If your carrier and plan support the technology, the necessary profiles are often downloaded automatically when you have internet access.
To activate, follow these steps:
- Open Settings and go to Cellular.
- Select the desired SIM card (if you have two) and click on “Wi-Fi calling”.
- Turn on the "Wi-Fi Calling on iPhone" switch.
- Accept the data transfer terms if a corresponding window appears.
Once enabled, the "Wi-Fi" icon should appear in the status bar next to the operator name "MTS RUS" or "MTS." This means the phone is ready to make calls over the wireless network. If the icon doesn't appear, try restarting the device or replacing the SIM card.
☑️ iPhone Setup Checklist
It's important to note that on some iOS versions, the menu may be named slightly differently, for example, simply "Wi-Fi Calling." It's also worth checking whether cellular data is disabled, as the phone still uses mobile data for initial registration with the IMS network, even if the call itself is made over Wi-Fi.
Instructions: setting up on Android
On devices running Android The process may vary depending on the manufacturer and version of the shell. The settings menu Samsung, Xiaomi or Huawei has its own characteristics, but the general principle remains the same.
The universal algorithm of actions looks like this:
- 📲 Go to “Settings” → “Connections” or “Network & Internet”.
- 📶 Find the "Mobile network" or "SIM cards and mobile networks" option.
- 📞 Find the "Wi-Fi Calling" option and enable it.
- 🏠 In the Preferences settings, select "Prefer Wi-Fi" or "Always use Wi-Fi".
On smartphones Samsung the path often looks like: Settings → Connections → Wi-Fi CallingOn . Xiaomi (MIUI): Settings → SIM cards and mobile networks → Use Wi-Fi for callsIf you can't find this option, use the settings search by entering the phrase "Wi-Fi."
Once activated, a corresponding icon (a handset with a Wi-Fi symbol) should appear in the notification shade or status bar. If the icon is lit but calls aren't connecting, check whether your router or antivirus software is blocking the ports required for the SIP/IMS protocol.
Table: Comparison of conditions and features
To better understand the differences between regular cellular and Wi-Fi calling, and how they are implemented across platforms, please refer to the table below.
| Parameter | Regular cellular communication | VoWiFi (MTS) | Messengers (WhatsApp) |
|---|---|---|---|
| Sound quality | Depends on the tower | High Definition (HD) | Depends on the Internet |
| Consumption of minutes | According to the tariff | According to the tariff (package) | Free (traffic) |
| Phone number | Your room number is | Your room number is | Account/Nickname |
| SIM-free operation | No | No (registration required) | Yes |
From the table it is clear that VoWiFi Combines the convenience of traditional telephony (your number and pre-paid minutes) with the benefits of internet calls (quality, coverage in areas without cellular coverage). This makes the technology ideal for offices, underground parking garages, and country houses with thick walls.
It's also worth keeping in mind that geolocation may be determined differently when calling via Wi-Fi than over a cellular network. Emergency services (112) may obtain the coordinates of the last known cell or IP address, so always state your exact address verbally when calling emergency services.
Troubleshooting and error recovery
Despite the simplicity of setup, users may encounter a number of difficulties. The most common issue is that the feature is enabled in the phone settings, but the icon doesn't appear, and calls fail. In 90% of cases, this is resolved by restarting the smartphone after enabling the feature.
If rebooting doesn't help, try the following steps:
- 🔌 Remove the SIM card, wipe the contacts and insert it back.
- ⚙️ Reset network settings (
Settings → System → Reset settings → Reset Wi-Fi & mobile networks). - 📱 Check for carrier profile updates in the App Store or Google Play.
- 🚫 Disable VPNs and proxy servers, as they may block IMS traffic.
Roaming problem
If you're abroad, make sure "Allow data roaming" is checked in your data roaming settings, even if you're calling over Wi-Fi. Otherwise, your phone won't be able to register with your MTS home network.
Another common error is "Failed to activate." This could mean your tariff plan doesn't support the service or your balance isn't sufficient for the test request. It could also be a problem with your carrier during maintenance.
⚠️ Attention: Menu interfaces and item names may change after iOS and Android updates. If you can't find the item you're looking for, search your phone's settings.
Call security and pricing
Many users are concerned that Wi-Fi calls will cost more or eat up all their data. We hasten to reassure you: minutes spent on calls over VoWiFi, are used from your basic MTS plan's minutes package just like regular calls. If you have unlimited minutes, they will also be unlimited over Wi-Fi.
In terms of data usage, voice calls are very economical. One minute of high-quality conversation uses only about 0.5–1 MB of data. Even if you have limited home internet, this is practically unnoticeable. Furthermore, data usage is not charged separately if you're within your home region.
An important security aspect: the connection between your phone and the operator's network is encrypted. Even if you're connected to an open Wi-Fi network at a cafe, interception of your conversation will be extremely difficult for attackers thanks to IMS encryption protocols.
⚠️ Attention: When roaming internationally, Wi-Fi calls may be charged as incoming and outgoing calls in your home region, but roaming data may be charged unless a special plan is activated. Check roaming pricing terms.
Frequently Asked Questions (FAQ)
Will minutes be deducted if I call via Wi-Fi?
Yes, minutes are deducted from your MTS tariff plan just like a regular call. If you have a minute package, they will be deducted from it. If the package is used up, the call will be charged at the per-minute rate.
What happens if the Wi-Fi connection runs out during a call?
If you move out of Wi-Fi range, modern smartphones (with Handover enabled) can automatically switch the call to a 4G/LTE cellular network without losing the connection, but this varies by phone model.
Does VoWiFi work if the mobile network is turned off?
Yes, if the phone is already registered with the IMS network. However, for initial activation and periodic SIM card status checks, the mobile network module must be enabled.
Why is there no Wi-Fi label on the operator icon?
It's possible your plan doesn't support the service, or your phone is in a strong cellular coverage area and prioritizing it. Also, check if the option is enabled in your smartphone's settings.
Is it possible to make calls via Wi-Fi if your phone is blocked?
No, your phone must be unlocked or have emergency calling capabilities to make a call. However, the VoWiFi connection status can be displayed on the lock screen.
⚠️ Attention: Network specifications and tariff terms are subject to change. For the most up-to-date information on your specific number, always check the official "My MTS" app.