Modern smartphone usage dictates its own rules, and we often find ourselves in situations where standard cellular service is unstable. This can occur in basements, country houses with thick walls, or in densely populated areas where base stations are overloaded. It's in these situations that technology Voice over Wi-Fi becomes a real salvation, allowing you to make calls over an Internet connection without loss of quality.
Operator MTS actively implements and supports this function, making it available to a wide range of subscribers with devices based on AndroidEnabling the service doesn't require complex router manipulation or manual IP address entry, as the process is fully automated. However, there are some nuances depending on your device model and current operating system settings that must be taken into account for proper operation.
In this article, we'll cover every step of VoWiFi activation, from checking plan compatibility to fine-tuning security settings. You'll learn how to distinguish an active Wi-Fi call from a regular one, which models support this feature out of the box, and what to do if standard methods don't work.
VoWiFi Technology: Operating Principles and Benefits
The technology known as VoWiFi Voice over Wi-Fi (Voice over Wi-Fi) transmits voice traffic over wireless networks, bypassing standard cell towers. For the user, this process is completely transparent: you dial a number and speak, but the signal is transmitted through your home or office router. This is especially relevant in "dead zone" areas where GSM/LTE signal strength is critically low or absent altogether.
The main advantage of using this technology is not only coverage but also battery savings. When a smartphone is in an area with a weak cellular signal, it begins constantly searching for a base station, increasing its transmitter power, which quickly drains the battery. Switching to Wi-Fi This reduces the load on the radio module and saves energy. Furthermore, the sound quality when using HD Voice codecs over a stable internet connection often surpasses that of a standard cellular connection.
⚠️ Note: For this technology to work, your router must support packet forwarding of a certain type, but 99% of modern models have this enabled by default. If you have a corporate network with strict traffic filters, access to VoWiFi may be restricted by your administrator.
It's important to understand that VoWiFi isn't an alternative to messaging apps or IP telephony. It's a fully-fledged replacement for cellular data at the operator level. The pricing for such calls is fully consistent with your main MTS tariff plan., meaning minutes are used from packages included in the tariff, and calls to MTS numbers within Russia remain free, just like with regular calls.
Checking device and tariff compatibility
Before you begin setup, you need to make sure your equipment and SIM card support the required functionality. Not all smartphones, even those released in recent years, are certified to work with these networks. MTS via Wi-Fi. This primarily applies to devices imported through parallel imports or intended for markets in other countries.
The list of supported brands is constantly expanding, but most models have basic support. Samsung, Xiaomi, Honor, iPhone (starting with certain versions of iOS) and Google Pixel. For AndroidIt's crucial for devices to have carrier profiles in their firmware that include MTS settings. If your phone was officially purchased in Russia within the last three to four years, the likelihood of support is over 90%.
When it comes to tariff plans, the operator is extremely flexible. VoWiFi is available on almost all current and archived plans. However, if you're using very old plans or corporate solutions with special terms, you may need to check the service status.
How do I know if my phone supports VoWiFi at the hardware level?
Technically, a Wi-Fi module supporting WPA2/WPA3 Enterprise security standards and voice traffic prioritization is required for operation. Modern Qualcomm and MediaTek chipsets implement this in hardware. The problem often lies not in the hardware, but in the software installed by the manufacturer or localizer.
Activation of the service on the operator's side
Unlike many other additional options, connecting Voice over Wi-Fi in most cases does not require sending USSD requests or calling the operator's support service. MTS implements this feature as a standard, so it's often enabled by default at the network level for all compatible subscribers. However, there are several ways to ensure this is the case and to force the option to be enabled if it's disabled.
The fastest and most reliable way to check is using a mobile app. My MTSIn the app interface, go to the service management section. There, in the additional features category or in the service search, look for an option called "Wi-Fi Calling" or "VoWiFi." If the switch is in the "Off" position, you need to enable it.
☑️ Checking service status
An alternative method is to use your personal account on the operator's official website. After logging in with your phone number and password (or code sent via SMS), go to your plan settings. The personal account interface may change, but the logic remains the same: find the section with additional communication services.
⚠️ Please note: Changes to your plan or activation of new services may take several minutes to take effect immediately. If your call still doesn't work over Wi-Fi after activating it in the app, try restarting your smartphone or turning Airplane Mode on and off.
Setting up an Android smartphone
After confirming service activation with your operator, the main setup process takes place directly in your smartphone's menu. The path to the required settings may vary slightly depending on your operating system version. Android and the manufacturer's proprietary shell (MIUI, One UI, Magic UI, etc.).
In most cases, the algorithm of actions looks like this:
- 📱 Open
Settingsyour device. - 📶 Go to the section
ConnectionsorNetwork and Internet. - 🔍 Find the item
Wi-Fi calling(may be called "Wi-Fi Calling"). - ✅ Turn on the switch and select a network priority (for example, "Prefer Wi-Fi").
For some models, especially Samsung, the path may be slightly different: Settings → Connections → Wi-Fi Calling. In devices Xiaomi And Redmi It is often necessary to access the SIM card settings: Settings → SIM cards and mobile networks → Select your MTS SIM card → Enable "Wi-Fi Calling"It is important that the wireless module on the device is enabled at this point.
Security settings deserve special attention. For this technology to work, your smartphone must have access to geolocation, as this is a regulatory requirement for emergency calls. Ensure location access is enabled in the privacy settings for your phone's system services.
Solving common connection problems and errors
Even with proper configuration, users may encounter situations where the feature doesn't work or works incorrectly. One of the most common issues is a missing icon. VoWiFi or Wi-Fi Call in the status bar after connecting to the network. This may mean the phone is unable to register with the operator's network via the internet.
The table below lists the main symptoms of problems and how to resolve them:
| Symptom | Possible cause | Solution |
|---|---|---|
| No VoWiFi icon | The service is not activated on the number. | Check the status in the My MTS app |
| Calls are being dropped | Unstable router signal | Move closer to the access point or reboot the router |
| Registration errors | Incorrect date and time | Enable automatic time synchronization |
| The phone doesn't switch | Priority is given to the mobile network | In the settings, select "Prefer Wi-Fi" |
Another common cause of outages is the use of "secure" DNS servers or VPN connections. VoWiFi protocols require a direct connection to the operator's servers, and encrypting traffic through third-party services can block this process. If you're using a VPN, try temporarily disabling it and check if the call icon appears.
Indication and control of expenses
Understanding how your connection is currently working is important for monitoring quality and costs. When the feature is active and working correctly, a special indicator appears at the top of your smartphone's screen, next to the Wi-Fi icon. Depending on your phone model, this may be a text message. VoWiFi, Wi-Fi Call or a telephone handset icon with a wireless network symbol.
It's important to distinguish this mode from calls via messengers. When calling via VoWiFi You use the standard dialing interface, your call history, and contacts. Costs are charged according to your MTS plan. If you have an unlimited minutes package, Wi-Fi calls are free with that package.
What happens if the internet connection runs out or the router turns off while I'm talking on Wi-Fi?
Modern smartphones support a handover feature. If the Wi-Fi connection is interrupted, the call will automatically and seamlessly switch to the 4G/LTE mobile network, provided there is coverage. This requires VoLTE support.
For precise control, you can use the expense breakdown in your personal account. Calls made over Wi-Fi may be marked with special tags or simply counted as regular voice minutes. It's recommended to periodically compare the minute counter in your operator's app with your own statistics, especially during the first few months of using the technology.
⚠️ Please note: When traveling abroad, rules may change. Calls made via Wi-Fi to Russian numbers from abroad may be charged as international calls or as roaming calls, even if you're using Wi-Fi. Always check roaming terms before traveling.
Frequently Asked Questions (FAQ)
Is there an extra charge for using VoWiFi?
No, the technology itself is not billed separately. You only pay for the minutes of calls according to your MTS tariff plan, just like when calling over a regular cellular network. Internet traffic is also not consumed, as the voice stream is transmitted over the operator's dedicated channels.
Can I use VoWiFi if my SIM card is very old?
In most cases, replacing your SIM card isn't necessary, as the service is tied to your number and network profile. However, if your SIM card is more than 10 years old and doesn't support 4G standards, identification issues may occur. In this case, we recommend replacing your SIM card with a USIM card at a mobile phone store for free.
Does this feature work if there is no mobile network at all?
Yes, this is one of the main advantages of this technology. If your phone is in "Flight Only" mode with Wi-Fi enabled, or simply in an area with no network coverage (like a basement or bunker) but there's Wi-Fi, you'll be able to make and receive calls as usual.
Why does the VoWiFi icon appear and disappear?
This could be due to an unstable Wi-Fi signal or temporary issues registering with the carrier's network. The phone may also automatically switch to the mobile network if the internet connection drops below a certain threshold required to ensure HD audio quality.