Mobile network operators have been focusing on leveraging the existing WiFi networks, which are becoming denser and faster every year, to make phone calls possible even from areas with very poor cellular signal, such as the outskirts of a cellular signal in the countryside or inside buildings or basements.
Activating WiFi calling takes just a few seconds, and the benefits are instantly noticeable. What many people who activate it don’t realize, however, is that WiFi calling shifts the responsibility for network optimization from the carrier to the end user.
WiFi analysis and troubleshooting applications such as NetSpot are indispensable for achieving the best possible call quality and preventing WiFi calls from suddenly being interrupted due to poor WiFi coverage.
Traditionally, when you make a phone call on your cell phone, you are connected to the person you’re calling through a cell phone tower. Cellular networks are comprised of many such towers, each emitting omnidirectional cell tower signals up to 100 watts of power.
Mobile network operators who own, maintain, and design these networks would like to cover every square inch with a strong, reliable cellular signal, but that’s unfortunately not always viable. Some areas are simply too out of reach or too scarcely populated to make it worthwhile for mobile network operators to construct expensive cell phone towers in such places.
Of course, a cellular signal isn’t always perfect even in major cities. Sometimes the signal doesn’t penetrate the thick walls of concrete buildings, sometimes it doesn’t reach far enough underground to cover subway stations and basements, and sometimes there’s so much interference that phone calls drop without any warning.
All of this is happening while nearly every household, every office, and every public place is covered with a strong WiFi signal. So, why not use it to make phone calls? From the carrier’s point-of-view, it’s just a simple matter of sending the same data over a different network. From the end user’s point-of-view, it takes just a few taps on the screen to activate the service, assuming WiFi calling is included in the end user’s plan.
Besides offering superior signal reception, WiFi calling also increases the audio quality of phone calls. Some mobile network operators support a feature called HD voice, which is high definition voice quality for telephony audio. Instead of being limited to the range of 300 Hz to 3.4 kHz, like traditional cell phone calls are, it uses a much wider range of 50 Hz to 7 kHz or higher. Of course, higher audio quality means higher bandwidth requirements.
In a way, smartphone users have been making WiFi calls for years. Apps like Skype, Viber, and WhatsApp make it possible to place calls over WiFi for free, and they even let users send text messages, share files, and make video calls. Collectively, these apps belong under the umbrella term VoIP (Voice over Internet Protocol). VoIP is defined as a methodology and group of technologies for the delivery of voice communications and multimedia sessions over Internet Protocol (IP) networks.
In other words, these apps use existing data networks such as the Internet for voice communications. Skype, Viber, and WhatsApp all operate on separate networks and don’t use the phone’s built-in dialer. Calling someone using these apps is possible only if the other party also has the app installed on his or her smartphone.
WiFi calling is built into the phone natively. It uses the phone’s native dialer and contact list. There’s no need to install any additional app, and only the person who wants to make a phone call over WiFi must activate the feature — the other party can be connected to a cellular network.
For example, with iPhone, WiFi calling can be activated on any iPhone 5c or later. WiFi calling iPhone works similarly to WiFi calling Android.
As such, WiFi calling requires little to no setup, yet it comes with many of the benefits of VoIP apps like Skype, Viber, and WhatsApp. Some carriers offer free WiFi calling, while others don’t.
1 mb per minute for calls
6-8 mb for video calls
Though the higher throughput you have the better your connection will be, a minimum of 1Mbps should be enough to patch a solid call through. Republic Wireless reports that it can hold a call with 80kbps, but the quality may decrease and you'll experience more dropped calls as well.
WiFi Calling is a service for smartphones that allows making calls over a Wi-Fi network. Your WiFi call is just like placing a regular call, but without using the cell tower. WiFi calling has a number of benefits, like the one when you are abroad and roaming data is very expensive. Your carrier usually determines whether you can make a WiFi call or not.
You don't have to install an additional app to make WiFi calls. However, you'll need the WiFi calling feature activated on your phone if you want to initiate the calls; the person you'll be calling doesn't need this feature to be activated on their phone, they will receive calls over cellular network, just as they always do.
WiFi Calling is a native feature of the majority of modern smartphones. If your phone is HD voice-enabled, then you can make WiFi calls after activating this feature in settings.
The Wi-Fi Calling feature is usually available at no additional cost, and is included in the existing monthly voice plan, however every operator is different and you have to check the pricing details with yours. Also, if you make international calls they most probably will be charged accordingly.