What is Wi-Fi calling, how does it work, and how to activate it on any mobile phone?

Android Guides » Android Tutorials » What are WiFi Calling, how do they work, and how to activate them on any mobile phone?

For some time now, Wi-Fi calling has revolutionized the way we communicate from our mobile phones , offering the possibility of making voice calls to any phone number using a wireless connection, without needing to rely on traditional mobile coverage. These types of calls are especially useful in environments where the carrier signal is weak, but a Wi-Fi connection is available, such as basements, building interiors, or even rural areas. In addition to not consuming mobile data, Wi-Fi calls typically offer excellent stability and quality, with the added advantage of being able to be made from anywhere with access to a wireless network.

In Spain, most major mobile operators already include this feature in their services, and a wide variety of smartphones are compatible with it . However, many users are still unaware of how it works and all the possibilities it offers. Imagine being able to make calls from your home, the office, or even a shopping mall without worrying about coverage, simply by connecting to the available Wi-Fi network.

What is WiFi calling and how does it work?

WiFi calling is a technology service that allows you to make and receive voice calls over a wireless internet network, instead of relying on your mobile network . It uses the Voice over WiFi (VoWiFi) protocol, which is essentially an advanced form of Voice over IP (VoIP), but implemented at the system level by the operator. This means that, from the user's perspective, making a WiFi call is exactly the same as a conventional call: the call comes out using your own number, is made through the standard phone app, and you can connect to any mobile or landline phone, regardless of whether the recipient is connected to WiFi or a mobile network.

Wi-Fi calling doesn't use traditional cell towers, but instead is routed through the broadband connection, whether fiber optic, ADSL, or another technology available in the location. This is especially useful in places with little or no mobile coverage but internet access, and allows for overcoming the physical limitations of cellular networks.

Main technical advantages:

• You can make and receive calls with your usual number, without installing additional applications.
• You don't depend on mobile coverage, just your WiFi connection.
• The person receiving the call doesn't need to be connected to WiFi or have the feature supported, just you as the sender.
• The call is billed (with most carriers) the same as a standard call, depending on your plan: if you have unlimited calls, they will also be billed over Wi-Fi.
• For international calls and calls to special numbers, the conditions are identical to those for a normal call.

All the advantages of WiFi calling

• Stable and high-quality communicationSince it's carried out over a broadband network and free from the interference inherent in mobile networks, the sound quality is typically superior and the call is less interrupted or echo-free. This is ideal for indoor use, in basements, and in areas with architecture that blocks coverage.
• Battery savingThe device doesn't need to constantly search for a mobile network, which helps reduce power consumption during Wi-Fi calls and extends the device's battery life.
• No mobile coverage requiredYou can call where your carrier's network doesn't reach, as long as you have access to Wi-Fi, eliminating the need to rely on cell phone towers.
• No external apps requiredIf your phone and carrier allow it, Wi-Fi calling is done from the standard phone app, without any additional steps or messaging services.
• No extra costsFor most carriers, charges are the same as regular mobile calls, with deductions for minutes or unlimited calls depending on the rate. Always check with your carrier for details on specific cases such as roaming or international calls.
• Emergency callsWi-Fi calling typically supports emergency number dialing, but the system may use the last known location of the cellular network, which is important to keep in mind when traveling.
• Full reception compatibilityYour caller doesn't need to have Wi-Fi calling enabled or be connected to a wireless network: they'll receive the call normally.
• Available on numerous terminalsFrom high-end to entry-level models, more and more phones support this technology, both on Android and iPhone, and from brands like Samsung, Xiaomi, Huawei, OPPO, Realme, and others.

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Wi-Fi Calling: How It Works, Pros, Cons, and Everything You Need to Know

Furthermore, Wi-Fi calling offers a seamless user experience, as there's no need to change how you make calls or notify the other person . Calls and SMS messages are handled through your usual number and appear as such on your bill, eliminating confusion with bundles or third-party apps.

Are WiFi calls the same as VoIP calls?

While both technologies allow voice transmission over a data network, Wi-Fi calling (VoWiFi) differs from traditional VoIP in key ways . Applications like WhatsApp, Telegram, Skype, and Messenger also allow calls using the internet, but:

• They require that both the sender and receiver have the same app installed, and in many cases, both must be connected to the Internet.
• VoIP calls are made between accounts, not between conventional phone numbers.
• Wi-Fi calling, on the other hand, uses your actual mobile number and doesn't change the experience: you can make and receive calls from any landline or mobile number, even if the recipient doesn't use the service or doesn't have internet access.
• For VoIP calls, minutes are not deducted from your call plan, but rather from your data allowance if you use a mobile network. For Wi-Fi calls, minutes are deducted based on your plan, and they do not consume mobile data if you make calls over Wi-Fi.

Disadvantages and aspects to consider

Despite their many advantages, WiFi calls also have certain limitations or disadvantages to consider :

• Dependence on the quality and stability of the Wi-Fi network: If the router is overloaded, the call may experience dropouts or poor quality.
• Not all business or public routers allow Wi-Fi calling, especially if they restrict certain ports or protocols.
• In international roaming, each operator determines whether it allows Wi-Fi calls from abroad and under what conditions they are billed.
• Service may not be available with prepaid rates from some carriers.
• The location identifier in emergency calls may not be as accurate as over the cellular network.

Which operators offer Wi-Fi calling in Spain?

In Spain, the rollout of Wi-Fi calling has been increasing. Among the main operators offering the service are:

• Movistar: It offers Wi-Fi calling on most of its contract plans, with a list of compatible devices primarily including Samsung and Huawei. Requires a specific SV-VoLTE software version.
• Q2: The service is included in all contract plans. Compatible with a range of Samsung and Huawei mobile phones, as well as some models from other brands.
• Orange: A pioneer in Wi-Fi calling, it offers compatibility with a wide range of devices from different manufacturers (Samsung, Apple, Huawei, Xiaomi, Sony, LG, OPPO, Wiko, Alcatel, among others). Applies to residential contract rates and some business plans.
• Jazztel: allows WiFi calls on compatible Android devices (with updated list on its website) and all iPhones since the 5S.
• Vodafone: It offers "Voice over Wi-Fi" on many of its plans, especially on its main contract lines, although the list of mobiles is more limited and requires confirmation from customer service.
• Other MVNOs and brands: Operators such as Amena (part of Orange), Yoigo, Pepephone, and MásMóvil are making progress in integrating the service, but it may not yet be available on all models or plans. They recommend checking their help pages or contacting support before changing plans or mobile phones.

Details and lists of compatible phones change frequently, so it's a good idea to check your carrier's website or app to see if your device and SIM support Wi-Fi calling.

How to activate and configure WiFi calling on your mobile phone

The process for activating and using WiFi calling varies slightly depending on the smartphone manufacturer and operating system, but it follows a series of common steps that we detail below for the main systems :

General steps on Android

1. Open the "Settings" application on your mobile phone.
2. Go to "Connections" or "Mobile Networks" (the name may vary depending on the brand and customization layer).
3. Select “WiFi Calling” and turn on the switch. Sometimes it may be under "Call Settings" or "More Networks."
4. Confirm that you have a SIM card inserted from a carrier that offers Wi-Fi calling and that your model is included among those supported.

• En Samsung: Settings > Connections > WiFi Calling.
• En Xiaomi: Settings > SIM cards & mobile networks > Selected SIM > Wi-Fi Calling.
• En OPPO and Realme: Settings > Wi-Fi & Internet > SIM & network > SIM 1 or 2 > Wi-Fi Calling.
• En OnePlus: Settings > Wi-Fi & Internet > SIM > Wi-Fi Calling.
• En Huawei: Settings > Mobile Network > Wi-Fi Calling.

General steps on iPhone

1. Go to Settings > Phone > Wi-Fi Calling and activate the function.
2. In some cases, you may also need to enable the "Wi-Fi Calling" option for the corresponding line in Settings > Mobile Data.
3. Once activated, you'll see the text "Wi-Fi" or the corresponding icon next to the operator's name in the status bar.

If the option doesn't appear, check that your system is updated to the latest version. On iPhones, this usually requires iOS 9.3 or later. On Android, the option is typically available from Android 6.0 onwards.

Checking that your call is really over WiFi

When you successfully make a Wi-Fi call, your phone will display a phone icon next to Wi-Fi waves in the top notification bar , or the text "Wi-Fi" near the carrier name in the status bar. This icon confirms that the call is being made over the wireless network and not the traditional mobile network.

If the icon disappears during a call, it could be because the Wi-Fi signal has weakened and your phone has automatically switched to the mobile network. If your Wi-Fi coverage isn't optimal, move closer to your router or access point to maintain call quality. The switch from Wi-Fi to the mobile network is usually seamless, although you might notice a slight interruption if the Wi-Fi connection is very weak.

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Compatible Devices: Which phones support WiFi calling?

Compatibility depends on the phone, carrier, and software version installed. Below, we list the most common models by carrier (remember to check your carrier's website for the most up-to-date list):

Compatible mobile phones on O2

• Huawei: Models from P30, P30 Pro, Mate 20 and Mate 20 Pro, as long as they have the compatible SV-VoLTE version.
• Samsung: From the Galaxy S9, S9+, S10, S10e, S10+, Note 9, to the Galaxy A50, A51, A71, Note 10, S20, and Lite and Ultra variants. See carrier-specified SV-VoLTE version.

Compatible mobile phones in Orange

• Samsung: Very wide range: from Galaxy S6, S7, S8, S9, S10, S20, A3, A5, A6, A7, A8, A50, A51, A71, Note 8 to Note 10, Note 10 Lite, Note 9, Note 10+, etc.
• Huawei and Honor: Recent models from the Mate, Nova and P Smart families, P20, P30, their Lite and Pro variants, and Honor 10 Lite.
• LG: Models G5, G6, G7 ThinQ, K30, K40, K40S, Q6, Q7, Q60, etc.
• Sony, Xiaomi, Oppo, Alcatel, Wiko, Apple: Mid-range and high-end models of each brand, especially the iPhone 5S and later and the Apple Watch from S3 onwards.

Compatible mobile phones in Amena

Amena announces full compatibility with all iPhone and Android devices, whether purchased through Amena or unlocked from another carrier. Prepaid and contract plans enjoy the service, although some contract plans may change billing according to Orange's policy.

Compatible mobile phones in Jazztel

• iPhone: From the 5S model onwards.
• Android: Check the Jazztel website to verify each model, prioritizing Samsung, Huawei, and models updated with the latest software version.

Compatible mobile phones on Vodafone

• iPhone: From 6S onwards, if the rate and software allow it.
• Samsung: From the S8 and later models. It's recommended to review each case with Vodafone support.

Remember: Although the list of compatible phones is constantly growing, not all models are supported by all carriers. If your phone doesn't show the option, it could be due to the software version, the SIM card, or the carrier's policy. Always consult technical support or the official website if you have any questions.

Frequently Asked Questions About WiFi Calling

• Do WiFi calls use mobile data? No, as long as you're connected to a Wi-Fi network, the call uses your broadband connection, not your mobile data plan. If the Wi-Fi signal is lost and your phone switches to the mobile network, the call will continue, but it will no longer be a "Wi-Fi call."
• Can you call emergency numbers? Yes, although the location may be based on the last location recorded by the mobile network and not the current exact location on the Wi-Fi network.
• Is a special rate required? No, Wi-Fi calling is typically available at no additional cost on most modern contract plans. For prepaid plans, please check your carrier's specific terms and conditions.
• Do I need to install additional applications? No, the mobile operating system and carrier settings manage the feature natively in the standard phone app.
• What happens if I'm abroad? The use of Wi-Fi calling while roaming depends on each carrier's policy. In many cases, it's only available on national Wi-Fi networks. Check conditions before traveling.

Tips and tricks to get the most out of Wi-Fi calling

• Keep your mobile operating system and apps updated to ensure maximum compatibility and security.
• Avoid using public or saturated WiFi networks for important calls, as they may cause interruptions or delays.
• If the service fails when activatedThis could be because your carrier has just enabled the service for your line, or because a pending update is pending. Wait a few hours or restart your device.
• Remember that you can easily disable the feature from the settings if you don't want to use it temporarily..

The arrival of Wi-Fi calling has represented a significant advance in mobile telephony, especially in areas where traditional coverage is lacking. It allows you to maintain accessibility and quality of communication without worrying about the geographical limitations of the mobile network, also improving the user experience indoors and reducing battery consumption in many cases. Its implementation is increasingly universal, compatible with most current devices, and based on secure and transparent protocols for the user. Taking advantage of this option can make a difference in your daily life, facilitating communication without interruptions or surprises on your bill.