How to make phone calls via Wi-Fi: step-by-step setup

Many people are familiar with the situation when the mobile network in a building is lost, but the internet is still available. At this point, regular calls become impossible, which can be a serious inconvenience, especially if you're waiting for an important call. However, modern smartphones allow you to bypass this limitation using technology. Voice over Wi-Fi (VoWiFi). This feature reroutes voice traffic over a wireless network, ensuring stable communication in areas where cellular base stations are unavailable.

Activating this option doesn't require installing third-party apps like messengers. Your number remains the same, and calls are charged according to your main plan. iPhone and devices based on Android This feature is supported natively, but it requires several conditions to be met by the carrier and proper configuration of the device itself. In this article, we'll cover all the details that will help you stay connected anywhere.

What is VoWiFi technology and how does it work?

Technology Voice over Wi-Fi VoWiFi is a standard for transmitting voice calls over IP. Unlike VoLTE, which uses 4G/LTE channels, VoWiFi utilizes any available Wi-Fi network to establish a connection. This solution is ideal for basements, office buildings with thick walls, or remote homes where cellular signal is weak or nonexistent.

The principle is that the smartphone creates a secure tunnel to the carrier's servers. The voice signal is digitized and transmitted as data packets. The process is virtually invisible to the user: the call comes in as a regular call, but a special indicator may appear on the screen. The sound quality often surpasses that of standard voice calls thanks to support for high-definition codecs.

⚠️ Attention: VoWiFi technology depends on support from your mobile carrier. Even if your phone supports the feature, it won't work without proper configuration from your service provider.

It's important to understand the difference between Wi-Fi calling and app calling (WhatsApp, Telegram, Viber). With VoWiFi, you call a regular phone number, and the other person doesn't need to be online or have a smartphone. It's a fully functional alternative to traditional cellular service, operating over the internet.

What is the difference between VoWiFi and Wi-Fi Calling?

Some manufacturers and operators use the term Wi-Fi Calling as a synonym for VoWiFi. Technically, these are the same solution, but the labeling may differ depending on the device brand (for example, Samsung often calls it Wi-Fi Calling, and displays a handset icon with a Wi-Fi symbol in the status bar).

Checking device and operator compatibility

Before setting up, make sure your equipment and data plan support this feature. Not all smartphone models released several years ago have a built-in voice-over-IP module. It's also important that your carrier offers this service in your region.

Basic device requirements include a specific operating system version and the appropriate software. Carriers are gradually introducing VoWiFi support, so the list of compatible models is constantly expanding. If you're using a custom firmware or an unlocked phone purchased abroad, the feature may not be available in the software, even if the hardware supports it.

Below is a table showing approximate compatibility between popular devices and operators (data may vary by region):

To check operator support, simply visit the provider's official website or call customer support. The service is often activated automatically the first time you try to make a call, but in some cases, activation is required in your personal account or via a USSD command.

Setting up Wi-Fi calling on iPhone

For smartphone owners Apple You're the luckiest of all: the activation process is extremely simplified and standardized. If your data plan supports the technology, the system will automatically prompt you to enable it after connecting to a wireless network. However, sometimes manual intervention is required.

To activate, go to the menu Settings, then select the section Cellular communications. Find the item Wi-Fi calling and toggle the switch to the on position. The system will ask you to confirm your emergency address—this is a mandatory requirement by regulators, as when calling over the internet, geolocation is determined by the router's IP address, not the cell tower.

If you don't see this option in the menu, try the following:

• 📱 Make sure your iOS is updated to the latest available version.
• 🔄 Restart your device after removing and re-inserting the SIM card.
• 📡 Check for operator settings updates in the section Basics → About this device.

⚠️ Attention: When calling emergency services (112, 102, etc.) via Wi-Fi, the operator may not receive your exact coordinates. Always provide the dispatcher with your verbal address if you are away from home.

After successful activation, the following message will appear in the status bar next to the operator's name: Wi-FiThis means all incoming and outgoing calls will now be routed over the internet. If the Wi-Fi signal weakens during a call, modern iPhones can seamlessly switch to a cellular network (provided they support VoLTE), without interrupting the connection.

Instructions for Android: Samsung, Xiaomi, and others

World Android The options are more varied, and the settings layout may vary depending on the manufacturer's shell. However, the logic remains the same: find the switch that controls voice calls over wireless networks.

On smartphones Samsung the path usually looks like this: open Settings, go to Connections and select Wi-Fi callingIf the item is not in the general list, go to the application Telephone, click on the three dots in the corner and select SettingsLook for an option with a similar name.

For devices Xiaomi (MIUI) and Honor the algorithm may differ:

• 🔍 Open the default app Telephone.
• ⚙️ Click on the settings gear or the three menu bars.
• 📞 Find the section Calling accounts or Calling over Wi-Fi.
• ✅ Activate the slider and select a priority network (for example, "Prefer Wi-Fi").

In some cases, especially on older versions of Android or custom ROMs, the function may be hidden in the engineering menu. Access to it can be done via a code. ##4636## in the dialer app. However, this method should be used with caution, as incorrectly changing the settings can result in loss of connection.

Troubleshooting connection issues and errors

Even with proper setup, users may encounter issues. The phone may not detect the network, drop calls, or simply not display the VoWiFi icon. Most often, the problem stems from a network settings conflict or an outdated carrier profile.

One common error is the device's failure to register with the IMS (IP Multimedia Subsystem) network. Without successful registration in this subnet, voice packets simply won't pass. It's also worth checking whether your router is blocking certain ports or protocols required for SIP telephony, although this is rare in home networks.

What to do if nothing works:

• 🔄 Reset your network settings to factory defaults (this will delete saved Wi-Fi and Bluetooth device passwords).
• 📲 Delete the operator profile and reinstall it through settings.
• 🌐 Try connecting to a different Wi-Fi network (for example, sharing internet from another phone) to rule out a router issue.

⚠️ Attention: Resetting network settings will delete all saved Wi-Fi passwords and paired Bluetooth devices. Make sure you remember the passwords for important networks before performing this operation.

Sometimes the problem can be resolved with a simple phone software update. Manufacturers regularly release patches that improve compatibility with carrier networks. Check for updates in the section System → Software Update.

The impact of internet quality on communications

The quality of voice communication over Wi-Fi directly depends on the stability and speed of your internet connection. Unlike data transmission, where peak speed is crucial, low ping (latency) and the absence of jitter (variance in delays) are crucial for voice.

For a comfortable HD conversation, a one-way speed of approximately 100 kbps is sufficient. However, if the channel is overloaded with other devices (such as someone watching 4K video or downloading files), audio quality may deteriorate, causing artifacts or interruptions. It is recommended to use a range 5 GHz, which is less loaded and provides more stable data transmission.

Factors affecting quality:

• 📉 Channel is overloaded with other devices.
• 📡 Distance to the router and number of walls.
• ⚙️ QoS (Quality of Service) settings on the router.

If you frequently use Wi-Fi calling, it might be a good idea to set up traffic prioritization on your router. In the settings QoS You can specify a priority for your smartphone or VoIP protocols. This ensures that even under high network load, the voice packet is sent first.

What is the minimum internet speed required for making calls?

For standard voice quality, 64-100 kbps is sufficient. HD voice (Wideband) requires a stable channel speed of about 1-2 Mbps. The key isn't speed, but ping stability (preferably less than 100 ms).

Do operators charge extra for VoWiFi?

In most cases, you'll be charged according to your base plan. Minutes are deducted from your bundle, just like a regular call. However, when abroad, Wi-Fi calls to numbers in your home country may be charged as roaming; check with your carrier for details.

Does VoWiFi work if there is no mobile network at all?

Yes, this is the main advantage of this technology. The phone can be in "No Network" or "Emergency Calls Only" mode, but when connected to Wi-Fi and the feature is activated, calls will still be made.