From 10 April, UK phone network EE's new Wi-Fi calling service will let you make calls using a Wi-Fi connection when you don't have any cellular signal.
Although it's not the first Wi-Fi calling service we've seen -- Skype and Google Hangouts, for example, already let you talk using Wi-Fi, rather than your phone connection, and US carrier T-Mobile has a similar offering in the States. It's the first UK network to bake the service directly into the phone, however, meaning you don't need a dedicated app.
To help you make sense of what Wi-Fi calling is, why it's important to you and what you can use it for, I've put together a handy guide to talk you through everything you need to know.
What actually is Wi-Fi calling?
Instead of using your network connection, you will connect to voice calls using the Wi-Fi you have at home, or using whatever Wi-Fi hotspot you happen to be on when you're out and about. In every other way it's like a normal call though -- you still use normal phone numbers.
Why do I want that?
The main benefit is for making calls when you have no phone signal. If you live out in the countryside, for example, and find it difficult to get phone signal, you can make calls and send texts using your home Internet connection instead. The same applies for when you're in those dingy, underground bars where your phone can't get reception, but can connect to the bar's Wi-Fi.
Isn't that what Skype does?
In a way, yes. There are various services that provide what's known as "voice over Internet", but EE's service is different. It's baked directly into the phone's dialler, so you don't need to fire up an app or connect to a service to use it. Once you lose phone signal, it will automatically switch to Wi-Fi calling.
That also means you don't need to add contacts to a service as you do with Skype. As it's built into the phone, you will have access to all your existing contacts and none of them will require an app to receive your call. With no setup and no contacts to add, EE's service requires no extra effort -- the only setting relating to Wi-Fi calling is to simply turn it on or off.
Which phones will it be available on?
EE's service will be launching on the Samsung Galaxy S6, theand the . Not all phones will support Wi-Fi calling and although EE wasn't willing to say yet precisely which phones will be able to make calls over Wi-Fi, it did say that almost all of the current crop of top end phones have the ability built in and will simply require a small software update.
EE reckons it'll have 5 million devices using Wi-Fi calling by the summer, and it's already a feature built into Apple's iOS 8, so expect to see it on the iPhone soon.
Does it cost more?
It doesn't cost any extra as such, but making calls over Wi-Fi will come out of your regular minutes allowance on EE. If you're running out of minutes, then using services like Skype or Google Hangouts will help you to avoid incurring any additional charges.
I'm not on EE, can I still use it?
You can't use EE's service, no, but other networks have similar offerings. Three has an app called InTouch, which you'll need to fire up in order to make calls or send texts, while O2's TU Go app does much the same. EE's is the only service that's built directly into the phone, meaning there are no extra apps to download.
Can I use it on holiday without paying huge amounts?
No, not on EE. It says it's just too complicated right now from a regulatory perspective and wants to avoid customers coming back from their summer trip with whopping charges on their bill.
If you're going abroad this summer and want to keep in touch, stick with Skype and WhatsApp when you're on your hotel Wi-Fi. Remember though, they do use data, which will cost you a lot if you're roaming on cellular networks. If you don't have a roaming plan, make sure you only use these services when on your hotel Wi-Fi and turn off data roaming in your settings when you head out into town.
Do I need a fast Wi-Fi connection?
EE reckons a 1Mbps connection will be sufficient for making calls over Wi-Fi, which is far below the national average. It'll apparently be possible on slower connections, but the quality will drop and it's possible you'll get some dropped calls too.