Modern mobile device usage often puts users in a difficult situation: while their home internet speed is excellent, their mobile connection keeps dropping out. This is especially true for owners of smartphones with metal cases or in homes with thick walls, where the signal from carrier base stations is blocked. MTS simply can't get through. In such situations, technology comes to the rescue. Voice over Wi-Fi, or, more simply, Wi-Fi calling.
Many subscribers mistakenly believe that a cell tower signal is required for conversations, but this is not true. The operator MTS Implemented support for the VoWiFi protocol, allowing you to initiate and receive calls using only a wireless network. This solution is ideal for basements, remote summer cottages, or office buildings with shielded floors.
In this article, we'll cover in detail how to activate this feature, which phone models support Wi-Fi Calling, and how to avoid unnecessary charges. You'll learn that calls to Russian numbers remain free within your plan, even if you're abroad but connected to a local network.
⚠️ Note: The settings menu interface may differ slightly depending on the operating system version. iOS or Android, as well as your smartphone model. If you don't see the item described, check the device manufacturer's official instructions to ensure the information is up-to-date.
What is VoWiFi technology and how does it work?
Technology VoWiFi Voice over Wi-Fi (Voice over Wi-Fi) is the transmission of voice traffic over the internet, bypassing traditional cellular radio channels. For operators, this is a way to improve coverage in areas where installing new towers is economically impractical or technically impossible. For subscribers, it guarantees constant connection and access to a hotspot.
The operating principle is similar to popular instant messengers, but there is a key difference. Unlike WhatsApp or TelegramWhere the other party must be online in the app, MTS Wi-Fi calls are made directly to a regular phone number. The other party won't even notice the difference; they'll receive a standard incoming call.
Connection quality in this case directly depends on the stability and bandwidth of your home network. If the router is overloaded or the channel is weak, voice quality may be intermittent. However, under normal conditions, the sound will be crystal clear, often better than a standard GSM network.
Technical details of the protocol
When using VoWiFi, the voice packet is encapsulated in IP packets and transmitted through a secure tunnel (IPsec) directly to MTS gateways. This ensures a high level of conversation encryption, comparable to banking security standards.
Free use terms and pricing
One of the most pressing questions is the cost of such calls. Operator MTS This service is positioned as a free option. Activation itself is free, and there is no monthly subscription fee. Pricing is fully consistent with the terms of your basic plan.
If your plan includes free minutes to Russian numbers, they will be used first when making calls over Wi-Fi. This applies to both incoming and outgoing calls. It's important to understand that this doesn't consume your internet traffic, as voice calls are transmitted over a dedicated channel, but connection stability is critical.
Using this service while roaming is especially useful. While abroad, you can connect to local Wi-Fi at a hotel or café and call Russian numbers at rates in your home region, as if you were in Moscow or St. Petersburg. This allows you to save significantly by avoiding international roaming charges.
Checking smartphone and SIM card compatibility
Before attempting to set up calls, you need to ensure that your equipment supports this technology. Not all phone models, even modern ones, have hardware or software support for VoWiFi on the network. MTSThis primarily applies to devices purchased from unauthorized dealers in the Russian Federation (gray imports), which may lack the necessary operator profiles.
The condition of your SIM card is also important. If you're using a SIM card that was issued more than 5-7 years ago, it may not support modern encryption and authentication standards required for VoWiFi. In this case, you'll need to replace your SIM card with a new one, which can be done free of charge at a mobile store or through your operator's app.
Below is a table of popular models that are guaranteed to support the feature when configured correctly:
| Brand | Model series | Support Features |
|---|---|---|
| Apple | iPhone 6 and newer | Requires current iOS version and carrier profile |
| Samsung | Galaxy S7 and later, A series | Support depends on the firmware region. |
| Xiaomi | Mi 9 and newer, Redmi Note 8+ | Manual activation via the engineering menu is often required. |
| Huawei | P30 and newer | Models without Google services may require an update |
If your model isn't on the list, that doesn't mean it won't work. The list of compatible devices is constantly expanding. You can check the status by contacting technical support or checking for the corresponding toggle in your phone's settings.
How to enable Wi-Fi Calling on iPhone
For device owners Apple You're luckier than everyone else, as this feature is implemented most transparently and works reliably in iOS. You don't need third-party apps or complicated code manipulation to activate it. All settings are located in the standard menu.
First, make sure your device is running the latest available operating system version. Then, open the default Settings app and go to the Cellular section. If you have two SIM cards, select the one associated with MTS.
Find "Wi-Fi Calling" and toggle the switch to "On." The system may ask you to confirm your emergency address—please provide up-to-date information, as this is required by law. Once enabled, the "Wi-Fi" icon will appear in the status bar next to your carrier's name.
☑️ iPhone Activation Checklist
In some cases, if the menu item is missing, you need to update your operator profile. To do this, go to Settings → General → AboutIf an update is available, a notification will appear. You can also try removing and reinserting the SIM card.
Setting up the feature on Android smartphones
With devices based on Android The situation is a bit more complicated due to the variety of shells and interface modifications. The logic remains similar, but the menu names may differ. In most modern smartphones (Samsung, Pixel, Motorola), this function is built-in by default.
Go to your phone's settings and find "Connections," "Network & Internet," or "SIM cards & mobile networks." Look for "Wi-Fi Calling." Enable it. Some Samsung models may require installing a special plugin. Wi-Fi Calling from the app store if it is not built into the firmware.
For phones Xiaomi, Huawei And Honor The situation depends on the regional firmware version. In global versions (Global ROM), this function is often present. In Chinese versions, it may be hidden. In this case, you can try entering the code into the dialer: ##869434##If the message "Wi-Fi Calling allowed" appears after entering this information, the feature is unlocked.
⚠️ Note: On some Android models, when Wi-Fi Calling is enabled, the phone may automatically switch mobile data to 2G/3G or disable data to prioritize voice traffic. This is normal behavior to ensure call stability.
Troubleshooting and troubleshooting
Even with proper configuration, issues can still occur. Most often, users encounter a situation where the Wi-Fi icon appears in the status bar, but calls still drop or fail. First, check to see if your router is blocking the ports required for SIP protocols. This is usually resolved by rebooting the router.
Another common issue is the phone clinging to a weak cellular signal instead of switching to Wi-Fi. In the cellular settings, you can find "Network Mode" and temporarily select "3G Only" or "4G Only" to forcefully disable 2G, which often interferes with the connection, or enable "Airplane Mode" altogether, leaving only Wi-Fi active.
If all else fails, try resetting your network settings. This will delete saved Wi-Fi passwords and Bluetooth settings, but often restores system services. Here's how to reset: Settings → System → Reset → Reset network settings.
- 📶 Make sure your internet speed is at least 1 Mbps for stable voice.
- 🔄 Restart your smartphone after enabling the feature for the first time.
- 🛡️ Check if you have an antivirus or firewall that is blocking connections.
Frequently Asked Questions (FAQ)
Will minutes from the package or tariff be deducted?
Yes, Wi-Fi calls are charged the same as regular cellular calls. If you have unlimited minutes, they aren't used up. If your minutes are limited, the call time is deducted from your plan.
Is it possible to make calls via Wi-Fi if the SIM card is blocked?
No, a SIM card must be active to authenticate with the operator's network and route calls. However, emergency calls (112) can be made over Wi-Fi even without a SIM card if the phone supports this feature at the software level.
Does Wi-Fi Calling affect data usage?
Voice traffic isn't billed like internet traffic; it travels over a dedicated channel. However, a minimal amount of data exchange occurs for network registration and signaling, but it's negligible and typically isn't billed by the operator.
What should I do if the Wi-Fi Calling icon is missing?
Check your account balance, whether your SIM card is active, and whether your internet connection is working. Also, try switching your phone to airplane mode and back to re-register.