Voice over Wi-Fi is nothing new, certainly when you consider how long services such as Skype and other over-the-top (OTT) apps have been around.
Early operator concerns about the impact of OTT services were well founded. Voice and text revenues were cannibalised by trendy new ways of making calls and sending messages via smartphone apps. In the wake of this, many operators decided that if they could not beat OTT players, they could at least join them.
Now, the next generation of Wi-Fi calling -- where the service is embedded in the smartphone and accessed via the normal phone dialler -- is offering operators a way to take back control by enabling them to provide voice services in areas where they have little or no coverage due to poor signal strength.
"It's cleaner and more simple, without the off-putting step of downloading an app," said Current Analysis analyst Peter Briggs. "Integrating it into the phone is the trend we see a lot. It has been available as a feature of Android for a long time. Now, it's also supported by iOS."
Others such as Three UK are taking an app-based approach, at least for now. The company noted that the advantages of this include that fact that the Three InTouch app is available on any iOS handset running version 6.0 and above or any Android handset running 4.0 and above.
In our latest special report we look at the approaches being taken by mobile operators in Europe to integrate Wi-Fi calling into their overall service offer. You can read the full report here.