Can I use WiFi to make calls when there is no signal?

Mobile phone signals aren't always as reliable as we'd like them to be, but the recent emergence of WiFi calling services may go a long way toward solving the problem of poor indoor mobile signal.

British mobile operator EE has launched a wireless network calling technology for smartphones, which allows people to make calls and send text messages via WiFi even if there is no signal. WiFi calling and texting do not take up much bandwidth, and about 500KB of broadband bandwidth per second is enough to support this service.

In fact, at Apple's press conference last September, Phil Schiller, Apple's senior vice president of global marketing, briefly introduced WiFi calling. Users can use the WiFi connection at work or home to improve call quality, enhance the signal, and automatically transfer the call to the mobile network after walking out of the building to a place with mobile signal coverage.

The principle and usage of WiFi calling

When using WiFi calling, your smartphone connects to your carrier's network via the internet, rather than your mobile signal. It sounds simple enough, but it actually uses several sophisticated signaling techniques.

For example, British mobile operator EE currently uses a system called "IP Multimedia Subsystem" to protect content that is not connected through its own mobile signal for secure transmission.

The most attractive thing about WiFi calling service is its simplicity and convenience, because this service does not require any applications, additional phone numbers, operator contract terms or additional fees. All we need to do is turn on the WiFi calling function in our smartphones and connect to WiFi.

When making a WiFi call, if the user walks out of the WiFi coverage area and has no mobile signal, the call will be cut off. But if the user walks out of the WiFi coverage area and has a mobile network signal, the call will be seamlessly transferred to the operator network.

WiFi calling is different from Internet calling

WiFi calling allows text messages and calls that were originally made through mobile operator networks to be transmitted via the WiFi network.

There are currently many applications and services on the market that allow users to make calls via the Internet. Although the principles of the two seem to be the same, there are actually essential differences between them.

For example, Skype users use a completely separate Internet number that cannot make emergency calls; Apple's Facetime service is only compatible with Apple devices and cannot call any landline or other brands of smartphones.

However, WiFi calling can support almost any type of phone, voice, and video calling. When using this service, users do not need to change their numbers, rely on the mobile operator's network, or launch any applications to complete it.

Not all phones support

However, not all smartphones support WiFi calling. EE says its WiFi calling service will be compatible with the Samsung Galaxy S6, S6 Edge and Microsoft's Lumia 640. It will also be available on the iPhone 6 and iPhone 6 Plus, Galaxy S5 and some other devices after receiving carrier updates.

As a winner of Toutiao's Qingyun Plan and Baijiahao's Bai+ Plan, the 2019 Baidu Digital Author of the Year, the Baijiahao's Most Popular Author in the Technology Field, the 2019 Sogou Technology and Culture Author, and the 2021 Baijiahao Quarterly Influential Creator, he has won many awards, including the 2013 Sohu Best Industry Media Person, the 2015 China New Media Entrepreneurship Competition Beijing Third Place, the 2015 Guangmang Experience Award, the 2015 China New Media Entrepreneurship Competition Finals Third Place, and the 2018 Baidu Dynamic Annual Powerful Celebrity.