The modern pace of life dictates its own rules, and staying connected is not just a convenience, but a pressing necessity. However, mobile network quality in buildings with thick walls, basements, or remote areas often leaves much to be desired, turning conversations into an intermittent stream of noise. This is where technology comes into play. Wi-Fi Calling, which allows the MTS operator to provide voice communication services via an Internet connection.
This feature isn't a third-party app like Skype or WhatsApp, but rather deeply integrated into the phone book and standard dialing interface. For the subscriber, this means their smartphone, without losing connection to a cell tower, automatically switches to an available Wi-Fi network, providing crystal-clear voice in areas where regular cellular service is ineffective. In densely populated metropolitan areas or in regions with difficult terrain, this is a lifesaver.
MTS is actively implementing and supporting this technology, focusing on connection quality in any conditions. Understanding how this feature works will not only improve your call quality but also save you money while traveling abroad. Below, we'll cover the technical details, the activation process, and any potential complications you might encounter.
⚠️ Attention: The settings interface may vary depending on your smartphone's operating system version and device model. If you don't see the options described, consult the manufacturer's official documentation or contact your carrier's account.
How VoWiFi technology works
The technology known as VoWiFi Voice over Wi-Fi (Voice over Wi-Fi) allows voice traffic to be transmitted over internet protocols, bypassing traditional cellular base stations. When you dial a number, your smartphone analyzes available networks. If the cellular signal is weaker than a certain threshold and the Wi-Fi connection is stable, the device redirects voice packets through the router. For the person on the other end of the line, this process is completely transparent—the call comes in as a regular call from your number.
The key element here is traffic encryption. MTS uses secure communication channels, guaranteeing conversation privacy even when using open Wi-Fi networks in cafes or airports. Security protocol It's in no way inferior to banking standards, as data is transmitted through a secure tunnel directly to the operator's gateways. This distinguishes the technology from messaging apps, where encryption depends on the app's settings.
It's important to understand that switching between networks is intelligent. If you're on a Wi-Fi call and move out of range but into a strong cellular network coverage area, the call may be transferred (if the device and network support it). handover), or the connection will simply remain stable due to buffering. However, most often, priority is given to the connection type established at the beginning of the call.
Technical details of packet transmission
Voice transmission over Wi-Fi uses packet switching technology. The voice signal is digitized, broken into small packets, and sent over the internet. Latency, under ideal conditions, should not exceed 150 ms, otherwise the conversation will become uncomfortable. MTS uses traffic prioritization (QoS) on its gateways to ensure voice packets travel faster than, for example, downloading large files.
Supported devices and requirements
Not all smartphones are compatible with Wi-Fi Calling, even if they support Wi-Fi for internet access. Proper operation requires hardware and firmware support, as well as operator certification. MTS is constantly expanding its list of compatible devices, which includes modern models from Apple, Samsung, Xiaomi and other popular brands.
First of all, your phone must support the standard VoLTE (Voice over LTE), as the Wi-Fi calling infrastructure is often tied to the same IMS profiles. The operating system must also be updated to the latest version, as older builds of Android or iOS may not contain the necessary drivers or carrier profile settings. Typically, iOS requires version 13 or higher, and Android requires version 8.0 or higher, although specific models may have limitations.
Additionally, your SIM card should be replaced with a new one if you're using a very old one, although in most cases, simply updating your network profile is sufficient. Make sure 4G/LTE is enabled in your mobile network settings, as service often depends on 4G registration.
Connection instructions for iPhone and Android
The process of activating the feature on iOS devices is extremely simplified and often occurs automatically. If your MTS SIM card is inserted into your iPhone, the settings may automatically apply after receiving the carrier profile. However, if this doesn't happen, you will need to manually check the settings in the device menu. Go to Settings → Cellular and select the desired SIM card if there are several.
Next, find the item Wi-Fi calling and turn the switch to the active position. The system may ask for confirmation of the address for emergency services (this is standard procedure for all operators). Once enabled, an icon will appear in the status bar next to the operator's name. Wi-Fi or an inscription MTS Wi-Fi, which indicates successful activation.
On Android smartphones, the path may differ slightly depending on the manufacturer's shell (MIUI, OneUI, ColorOS). Typically, the setting is located along the path Settings → Connections → Mobile network → Wi-Fi callingIn some models, the option may be hidden in the menu of the Phone application itself: click on the three dots in the corner, select Settings and activate the desired function.
☑️ Pre-activation check
Roaming pricing and savings
One of the main advantages of using Wi-Fi Calling is the ability to save money while roaming. When you're abroad but connected to local Wi-Fi (at a hotel, cafe, or airport), incoming and outgoing calls to Russian numbers are charged as if you were in your home region. This means you won't be charged international roaming fees, and your minutes will be used from your basic plan.
It's important to note that for outgoing calls to numbers in your home country (where you're physically located), your home region's call rates will apply, not roaming rates. This can be significantly cheaper. However, if you're calling a third country, your MTS plan's international call rates will apply.
It's worth remembering that Wi-Fi Calling traffic isn't billed separately if you're using your home internet connection. However, if you're connected to paid Wi-Fi at a hotel or airport, you'll be charged according to the provider's rates for the amount of data transferred. Voice traffic consumes a small amount of resources, approximately 1-2 MB per minute, but this is something to consider if you're using paid access.
| Call type | While in Russia | While roaming (via Wi-Fi) |
|---|---|---|
| Incoming calls from a Russian mobile phone | Free (according to tariff) | Free (like at home) |
| Outgoing call to Russian mobile phone | Package minutes | Package minutes |
| Outgoing to a local number | Russian mobile phone rates | Call rates from Russia to this country |
| Incoming from abroad | For free | For free |
Possible problems and solutions
Despite the technology's robustness, users may encounter various difficulties when connecting or during use. Often, the problem stems from the device not detecting the carrier's network to register for the service. In this case, rebooting the smartphone or temporarily enabling airplane mode for 10-15 seconds helps, forcing the phone to re-register with the network.
Another common situation is when the Wi-Fi Calling icon appears, but calls fail or are dropped. This may indicate a slow internet connection or high latency (ping). For stable operation, a speed of at least 1-2 Mbps is recommended. Issues can also occur if strict NAT filtering is enabled on the router or if certain ports required for SIP protocols are blocked.
If the feature stopped working after a system update, your access point name (APN) settings may be incorrect. Check that the correct parameters are entered in the MTS mobile network settings: name internet.mts.ru, login and password mtsSometimes deleting the old operator profile and reinstalling it through the settings menu helps.
⚠️ Attention: If you're using corporate Wi-Fi networks with web-based authentication (captive portal), Wi-Fi Calling may not work until you log in through your browser. Some secure corporate networks may block voice traffic entirely.
Comparison with messengers and alternatives
Many users wonder: why use Wi-Fi Calling when you have WhatsApp, Telegram, or Viber? The main difference is integration. You don't need the other person to have the same app installed, nor do you need to add them to your contacts within the app. You simply dial the number as usual. This is especially important for calling government agencies, banks, or elderly relatives who don't know how to use smartphones.
Furthermore, Wi-Fi Calling often offers higher audio quality thanks to the HD Voice codec, which provides a wider frequency range. Messengers, on the other hand, rely heavily on compression algorithms, which can degrade audio quality on unstable internet connections. It's also important to remember to call 112: Wi-Fi Calling ensures emergency calls work correctly with geolocation (if enabled), whereas messengers may not always be able to transmit precise coordinates to rescuers.
In terms of battery consumption, the carrier's native feature is better optimized than a constantly running background messenger that must maintain a connection for push notifications. However, with a very weak Wi-Fi signal, the phone may waste more power on constant reconnection attempts than it would on a regular cellular connection.
Why might calls via instant messaging apps be worse?
Messengers share the same internet connection as other apps. If a file is downloading or updating in the background, the voice stream may be interrupted. Wi-Fi Calling prioritizes packet processing at the operator and smartphone level, ensuring stability.
Frequently Asked Questions (FAQ)
Will minutes from my package be deducted if I make calls via Wi-Fi?
Yes, you'll be charged according to the terms of your main MTS plan. Minutes are used from the bundles included in the plan, just like when making a call over a cellular network. If the bundle is used up, you'll be charged per minute.
Is it possible to use Wi-Fi Calling if there is no cellular network coverage at all?
Yes, this is the primary purpose of the technology. If "Wi-Fi Only" mode is enabled, or if there's no cellular network but the internet is available, calls will be made exclusively over Wi-Fi. A corresponding indicator will appear on the screen.
Does Wi-Fi Calling work with virtual operators (MVNO)?
MTS provides this service to its direct subscribers. Virtual operators using MTS infrastructure may not support this feature, as special configuration is required on the operator's network core. It is recommended to check with your specific provider.
How do I know if a call is being made via Wi-Fi?
This is indicated by a special icon in the status bar (usually a handset with a Wi-Fi symbol or the words "MTS Wi-Fi"). A corresponding indicator may also appear on the screen during a call, depending on the phone model.
Do I need a separate app for Wi-Fi Calling?
No, an app is not required. The function is built into the smartphone's operating system and works through the standard dialer. Downloading third-party MTS apps is not necessary, and may even conflict with the system function.