Modern mobile communication standards require stable coverage at all locations, but the physics of radio waves often dictates its own conditions: thick walls of office buildings, basements, or distance from a base station can completely deprive you of a signal. It's in these situations that technology comes to the rescue. VoWiFi, which allows you to make calls and send messages over Wi-Fi, bypassing traditional cell towers. MTS is actively implementing this feature, allowing subscribers to stay connected even in areas where traditional cellular coverage is unavailable.
Activating the service doesn't require complex equipment or special data plans. Your smartphone must support the standard and have the appropriate option enabled in your settings. The activation process may vary depending on your device's operating system and firmware version, so it's important to know the exact steps for your specific model. In this article, we'll cover in detail how to activate the feature on different platforms, which models support the technology, and how to troubleshoot possible connection errors.
Before we dive into technical details, it's worth noting that voice quality directly depends on the stability of your internet connection. If the router is far away or the channel is congested, voice quality may be interrupted, despite the technology being in place. Wi-Fi Calling — This is a great way to improve communication in areas with poor reception, but it requires proper configuration both on the operator's side and in the menu of your gadget.
What is VoWiFi technology and how does it work?
Technology Voice over Wi-Fi (or simply Wi-Fi Calling) is a method of transmitting voice traffic over internet protocols, similar to how popular instant messaging apps work, but integrated into a standard phone book. When you dial a number, your smartphone analyzes available networks and, if the cellular signal is weak but Wi-Fi is available, automatically switches the connection to a wireless network. To the other person, the call appears like a regular incoming call, without the need to install additional apps.
The key advantage is the use of your existing data plan: minutes are deducted from your package, and the connection quality often surpasses standard 2G/3G, especially in buildings with thick walls. MTS uses secure encrypted channels, so conversations remain private. It's important to understand that this feature differs from WhatsApp or Telegram calls in that it operates within the phone's system settings and doesn't require the recipient to have the app installed.
The technology's operation depends on support from several components: the SIM card, the tariff plan, the operator's equipment, and, of course, the smartphone itself. MTS provides network-side support, but the end result depends on how well your device can interact with the operator's IMS profile.
⚠️ Please note: Wi-Fi Calling connection quality directly depends on your home internet speed. If your provider is experiencing bandwidth issues, calls may be dropped or delayed, even if everything is working perfectly.
Roaming is also worth mentioning. While abroad, you can connect to a hotel's local Wi-Fi network and call Russian numbers at your home region's rates, avoiding international roaming charges, provided the service is activated in advance.
Checking device and tariff compatibility
The first step before setting up should be checking the compatibility of your hardware. Not all smartphones, even modern ones, have built-in support for the protocol. IMS For a specific operator. MTS maintains a list of supported devices, which is regularly updated as new firmware is released and models are certified.
Most often, issues do not occur with flagship Samsung, iPhone, Xiaomi, and Huawei models from recent years. However, if you have a budget smartphone or a device imported into Russia without an official warranty, the function may be blocked by the manufacturer. In such cases, the default menu settings may not display the required toggle.
In addition to the hardware, you need to check the status of your SIM card. VoWiFi is free, but it must be enabled on the network. It's usually activated automatically for modern plans, but older plans may require updating the service terms or replacing the SIM card with a new one that supports 4G/5G.
- 📱 Make sure your smartphone model is on the list of supported MTS devices.
- 📶 Check if the latest version of the operating system is installed and the basic network settings are updated.
- 💳 Make sure your SIM card is registered in your name and your tariff plan is active.
- 🌐 For this feature to work, you need a stable Wi-Fi connection.
List of popular supported models
The list of guaranteed supported devices includes the iPhone 5s and later (iOS 13+), Samsung Galaxy S7 and later, and most Xiaomi models (Mi 9 and later, Redmi Note 8 and later) with the latest firmware. It's best to check the full list on your carrier's official website, as it's constantly expanding.
How to enable Wi-Fi Calling on Android
In the Android operating system, the path to activating this feature may vary depending on the manufacturer's operating system (MIUI, One UI, ColorOS, etc.). However, the general principle remains the same: you need to find the section responsible for mobile network or SIM cards. Most often, the switch is located in the menu. Settings → Connections → Wi-Fi Calling.
On Samsung devices the algorithm is a little different: go to Settings → Connections → Wi-Fi Calling and activate the slider. If you don't see this option, try searching for "Wi-Fi Calling" in the settings search. On some Xiaomi and Redmi models, the feature may be hidden in the menu. Settings → SIM cards and mobile networks → Wi-Fi use, where you need to select the preferred network type.
☑️ Activation checklist for Android
Once enabled, a corresponding icon should appear in your phone's status bar. This is often a phone icon labeled "Wi-Fi" or "VoWiFi." If the icon doesn't appear immediately, try restarting your device or toggling airplane mode on and off. This will force your phone to re-register with your carrier's network and pick up the service profile.
⚠️ Note: The settings interface may change after updating the operating system. If you don't find the described options, search your phone's settings by entering the keywords "Wi-Fi" or "Calls."
It's important to set network priority correctly. The function menu usually offers three options: "Prefer Wi-Fi," "Prefer Mobile Network," or "Don't Set." For maximum performance in areas with poor reception, it's best to choose the first option, so the phone always tries to use the wireless network for calls if available.
Setting up the feature on iPhone (iOS)
Apple smartphone owners are lucky to have a unified interface that remains virtually unchanged from model to model. To activate VoWiFi on iPhone, open Settings → CellularIf you have two SIM cards (or eSIM), select the one for which you want to enable the feature (for example, "MTS").
In the menu that opens, find the item Wi-Fi calling and toggle the switch to the on position. The system may request address verification for emergency services—this is a standard procedure required by regulators, even if you're located in Russia. Once confirmed, the feature will become active.
On the lock screen or in the status bar, "Wi-Fi" will appear next to the carrier name. This means your phone is ready to route voice traffic over the internet. iOS features smart switching: if you move out of range of your router during a call, your iPhone will attempt to seamlessly switch to the cellular network without interrupting the connection, provided coverage allows.
| Parameter | Android | iOS (iPhone) |
|---|---|---|
| Path to the menu | Settings → Connections | Settings → Cellular |
| Function name | Wi-Fi Calling | Wi-Fi calling |
| Indicator | Wi-Fi handset icon | The text "Wi-Fi" next to the operator |
| Emergency services | Address request (depending on model) | Address entry is required |
Troubleshooting connection issues and errors
Even if you follow all the instructions, users may encounter situations where the feature doesn't activate. One common cause is an outdated carrier profile. On Android, this can be resolved through the Google Play Store (under "System Updates" or the separate "Carrier Settings" app), and on iOS, by updating the cellular network configuration.
Another common issue is conflicts with VPN services or ad blockers. Since VoWiFi requires a direct connection to the operator's servers, any tunneling software can block this traffic. Try temporarily disabling the VPN and checking if it works. It's also worth making sure your router doesn't have strict port filtering, although in 99% of cases, home routers don't interfere with the service.
If all else fails, it might be worth resetting your network settings. This will delete saved Wi-Fi passwords and Bluetooth settings, but it will return all network settings to factory defaults, which often resolves software glitches. Here's how to reset: Settings → System → Reset → Reset network settings.
- 🔄 Update your carrier settings through the app store or phone menu.
- 🛡️ Disable your VPN and antivirus firewalls during the scan.
- 📡 Restart your router and smartphone to update the IP addresses.
- 🔧 Reset network settings if other methods don't help.
⚠️ Note: Resetting network settings will delete all saved Wi-Fi network passwords. Make sure you remember your home internet password before performing this operation.
In rare cases, the problem may lie with the router itself. Some older models or firmware with aggressive power-saving settings can interrupt the connection needed to maintain a VoWiFi session. Check if you have a limit on the number of connected devices or if "Guest" mode, which isolates devices from each other, is enabled.
Advantages and Disadvantages of Using VoWiFi
Use of technology Wi-Fi Calling This offers clear advantages for those living in homes with poor signal penetration or in office buildings. You get stable HD voice without the interference and "croaking" typical of 2G. It also saves battery life, as the phone doesn't have to constantly search for a base station signal at maximum power.
However, this technology does have its own peculiarities. The main drawback is its dependence on internet quality. If someone on your network starts downloading large files or watching 4K videos, voice quality may degrade, as traffic priority (QoS) is often not configured on typical home routers. It's also worth considering that when moving from a Wi-Fi zone to a cellular network, there may be a brief connection interruption if the phone doesn't have time to switch.
Another nuance concerns roaming. Although the technology allows you to make calls at domestic rates from abroad via Wi-Fi, some operators may block this feature if you're in certain countries or require you to activate the "Data Roaming" option in advance. Always check with MTS before traveling.
Impact on battery
Using VoWiFi can both save and drain your battery faster. Battery savings occur when the phone doesn't waste resources searching for a cellular network. Battery consumption increases if the Wi-Fi signal is weak and the phone constantly tries to maintain a connection, or if large amounts of data are constantly being transferred while talking.
Frequently Asked Questions (FAQ)
Does MTS charge an additional fee for using Wi-Fi Calling?
No, the technology itself is free. Call minutes are charged according to your basic plan, just like regular minutes. However, voice traffic may be metered by your home internet provider unless you have an unlimited plan, although the data allowance for voice calls is minimal.
Can I use Wi-Fi Calling if my SIM card is very old?
Most likely not. This technology requires a 4G-enabled SIM card (USIM). If your SIM card is old and large (a cut-SIM or micro-SIM without a 4G chip), you'll need to replace it at an MTS store with a new one, keeping your phone number.
Does the feature work if mobile data is turned off?
Yes, it works. VoWiFi uses a Wi-Fi channel, so mobile internet (3G/4G/5G) may be disabled. However, the Mobile Communications service itself must be active, and in some cases, a short cellular signal is required for initial registration with the IMS network.
Why does the VoWiFi icon appear and disappear?
This may indicate an unstable Wi-Fi signal or intermittent loss of connection to the carrier's servers. This behavior is also typical when power saving mode is enabled, which can "kill" the background process of the phone service. Try adding your phone book or phone service to the power saving exceptions.
Does the other person hear a difference in sound quality?
Yes, if both devices support HD voice (VoLTE/VoWiFi), the sound will be significantly clearer, with a wider frequency range. The other person may not notice the technology, but they will appreciate the lack of noise and a more natural-sounding voice.