The iPhone X is barely a month old and already people want to know about future iPhones and what they might feature.

Well, the rumour mill is already discussing the 2019 iPhone: according to a Bloomberg, Apple is developing a “3D sensor” for the back of that iPhone. It's mulling a different technology from the TrueDepth sensor system found on the front of iPhone X. That system projects a pattern of 30,000 laser dots onto your face to generate an accurate 3D image for authentication. The rear-facing sensor would work differently.

It would use a "time of flight" approach, which calculates the time it takes for a laser to bounce off surrounding objects, in order to create a 3D image of your environment. What's the point of that? To enhance Apple’s augmented reality apps and services, of course. The new iPhone would be able to provide 3D awareness of not only your face but also your surroundings while also establishing a depth map.

Apple’s ARKit can already serve up impressive AR experiences on iOS devices, so it'll be interesting to see how this 3D sensor fits in with that platform. Bloomberg said that Apple is talking with suppliers, though that doesn't mean it will make it into the 2019 iPhone.