Modern communication standards allow making voice calls not only through cellular operator base stations, but also using an Internet connection. Technology VoWiFi Voice over Wi-Fi is becoming increasingly important, especially in densely populated urban areas or remote areas where mobile network coverage is unstable. For MTS subscribers, activating this feature means they can always stay connected, even if their smartphone screen only displays a single network bar or a "no service" sign.
Enabling wireless calling requires several conditions to ensure stable operation. First and foremost, this means your device must support the technology and your data plan must be configured correctly. In this article, we'll cover in detail how to activate the feature on different types of smartphones, what nuances to consider when moving between coverage areas, and how to troubleshoot common connection issues.
It's worth noting that the transition to IP telephony within the operator's network is seamless for the user, but audio quality can improve significantly thanks to high-definition codecs. If you frequently spend time in buildings with thick walls, basements, or at your dacha where the only available service is Wi-Fi, this guide will be an indispensable tool for improving your connection quality.
Technological features and equipment requirements
Before you begin setting up, you need to make sure that your equipment is technically ready to work with modern voice transmission protocols. Technology VoWiFi It's based on IMS (IP Multimedia Subsystem) standards, which requires a corresponding module in the smartphone and firmware support. Not all devices, even those released in recent years, have this feature unlocked for Russian carriers.
The second critical requirement is having the latest software version. Telecom operators regularly update settings profiles, and on older versions Android or iOS The menu item may simply be missing or malfunctioning. It's also important to have 4G/LTE service activated on your SIM card, as VoWiFi often relies on packet switching technologies.
⚠️ Attention: If the feature doesn't appear after all the settings, your tariff plan may be archived. In this case, please contact MTS support to confirm the service's availability on your phone.
A stable connection also requires a router that supports security standards and doesn't block the ports needed to transmit voice traffic. While such issues are rare in home networks, corporate Wi-Fi networks may have limitations. Ensure your internet speed is at least 1-2 Mbps for a single, high-quality, simultaneous call.
Preparing your smartphone for VoWiFi activation
The initial setup step involves properly preparing your device. First, you need to update your carrier profile. On most modern smartphones, this happens automatically when you have internet access, but sometimes you may need to manually update your network settings. Go to your cellular settings and check that MTS is selected as your primary data provider.
Next, you should check the status of your SIM card. If you're using an old SIM card from many years ago, it may not support new security protocols. In this case, SIM card replacement Buying it at a mobile phone store or through a courier will be a mandatory step. The new MTS SIM card already contains the necessary encryption keys for working with the IMS network.
It's also important to ensure that your phone doesn't have any modes that block background activity or data transfer enabled. Power-saving modes can disable Wi-Fi when the screen goes dark, causing calls to drop. Set up exceptions for your phone's system services to ensure uninterrupted communication.
☑️ Checking device readiness
How to enable Wi-Fi calling on Android
In the operating system Android The location of the settings may vary depending on the smartphone manufacturer and the version of the shell. However, the general algorithm remains the same for most devices, including Samsung, Xiaomi, Realme and others. First, open the main settings menu and find the section responsible for connections.
On devices with clean Android the path usually looks like this: Settings → Network & Internet → Mobile Network → Wi-Fi CallingHere you need to switch the switch to the active state. On smartphones Samsung the menu may be called "Connections" and on Xiaomi — "SIM cards and mobile networks." In some cases, this option is hidden in the "Advanced" menu.
If you can't find the setting using the standard search methods, use the phone settings search. Enter "Wi-Fi" or "VoWiFi" in the search bar, and the system will automatically suggest the appropriate menu item. Once activated, a corresponding icon should appear in the status bar next to your carrier's name.
For Samsung, go to Settings → Connections → Mobile Network → Wi-Fi CallingFor Xiaomi, go to Settings → SIM cards and mobile networks → Wi-Fi calling.
For Huawei/Honor: Settings → Mobile network → Wi-Fi calling
It's important to set network priority correctly. The system allows you to choose which network to use first when receiving an incoming call. We recommend setting "Wi-Fi Preferred" so that the phone automatically switches to a wireless network when the cell signal is weak.
What to do if the menu item is missing on Android?
If you can't find the switch, try resetting your network settings to factory defaults. This won't delete your personal data, but it will return your connection settings to their default state. The option may reappear after a reboot.
Setting up iPhone: Activating the feature on iOS
For smartphone owners Apple I was lucky with a more unified interface, but there are some nuances here too. To enable the function on iPhone you need to go to the section Settings → CellularIf you have two SIM cards (physical and eSIM), select the one from MTS.
In the menu of the selected SIM card, find "Wi-Fi Calling" and enable it. After turning it on, the system may ask you to confirm your address for emergency services. This is a mandatory requirement by communications regulators: when calling emergency services online, the operator must know your location.
For this feature to work properly on iOS, you also need to enable cellular data, even if you plan to only make calls over Wi-Fi. This is necessary to register your device with the IMS network. Make sure "Allow switching" is enabled in the "Cellular Data" section.
⚠️ Attention: When moving to another country, this feature may be automatically disabled to avoid roaming charges, even if you're connected to Wi-Fi. Before your trip, check your settings in the "Cellular Data" section.
If "MTS Wi-Fi" doesn't appear in the status bar after enabling this feature, try restarting your device. iOS often requires restarting network services to apply new carrier profiles. Also, check if background refresh is restricted in the Phone app's privacy settings.
Comparison of technologies: VoLTE and VoWiFi
Many users confuse the two advanced voice transmission technologies, believing them to be the same thing. In fact, VoLTE (Voice over LTE) and VoWiFi They solve similar problems but use different data transmission channels. Understanding the differences will help you more effectively manage connection quality in different situations.
VoLTE transmits voice traffic over fourth-generation (4G) networks, providing high-quality audio and fast dialing. VoWiFi, on the other hand, uses any available internet connection via the Wi-Fi protocol. Both technologies require operator and device support but operate in different frequency bands.
| Characteristic | VoLTE (4G) | VoWiFi (Wi-Fi Calling) |
|---|---|---|
| Transmission channel | 4G/LTE cellular network | Internet (Wi-Fi router) |
| Dependence on coverage | Need an MTS tower nearby? | All you need is a router |
| Sound quality | HD Voice (high) | Depends on the internet speed |
| Traffic consumption | Not charged (usually) | Router traffic is being consumed |
The main advantage of VoWiFi is the ability to make calls in places where there's no physical cellular network, such as a deep basement or a building with shielded walls. VoLTE, on the other hand, provides better mobility when moving around the city, as it doesn't require tying to a specific access point.
Troubleshooting and diagnostics
Despite the technology's robustness, users may encounter connection difficulties. One of the most common issues is the absence of the "Wi-Fi Calling" icon after completing all the settings. In this case, first check whether the device is registered with the IMS network. This can be done through the engineering menu or special diagnostic apps.
Another common issue is call drops when switching between networks. When you leave the Wi-Fi range, your phone should automatically hand over to the cellular network (handover). If this doesn't happen, your router may have strict firewall or NAT settings that block long SIP sessions.
- 📶 Problem: Calls are coming through, but the other person can't hear you. Solution: Check the Phone app's microphone permissions in your privacy settings.
- 🔄 Problem: The phone constantly switches between 3G and Wi-Fi. Solution: In your mobile network settings, temporarily disable 3G, leaving only 4G/LTE to stabilize priorities.
- 🔋 Problem: The battery drains quickly when the function is enabled. Solution: This is normal if your Wi-Fi signal is weak, as the module is operating at increased power. Try moving closer to the router.
If you use a dual-SIM phone, make sure the settings are configured individually for each SIM card. Sometimes, activating the feature on one SIM card resets the settings on the other. It's also worth checking whether your antivirus software is blocking network connections for system processes.
⚠️ Attention: When calling emergency services (112, 102, 103) via Wi-Fi, the dispatcher may not see your exact address, as geolocation based on the router's IP address has a significant margin of error. Always state your address verbally.
Frequently Asked Questions (FAQ)
Is there an extra charge for Wi-Fi calling?
No, MTS doesn't charge separately for VoWiFi. Minutes are charged from your main package according to your tariff plan, just like regular calls. However, if you're abroad, roaming rules may apply, even when connected to Wi-Fi, so check your tariff plan before traveling.
Does this feature work if I turn off my mobile internet?
Yes, calls will be made exclusively over Wi-Fi. However, for the initial device registration in the IMS network and checking the SIM card status, a short period of cellular network access is required. After successful registration, calls can be made even with mobile data turned off.
Why does the screen say "MTS Wi-Fi" instead of MTS?
This is standard system behavior, indicating that voice transmission over the wireless network is currently active. Once you leave the router's range or the signal quality degrades, the message will change to the standard operator name or "MTS LTE."
Can you use VoWiFi on tablets?
Technically, this is possible on tablets with SIM card support and telephony functionality, but the interface of most tablet operating systems isn't optimized for voice calls via the standard dialer. Messenger apps or ecosystem-based dialers (for example, calling from iPhone to iPad) are most often used for this purpose.
Does a router affect sound quality?
Absolutely. Older 802.11b/g routers or congested airwaves in apartment buildings can cause delays and audio artifacts. For the best quality, it's recommended to use dual-band routers (2.4 and 5 GHz) and connect to the 5 GHz network if the phone is close to the signal source.