Heated competition from Samsung and Android devices has made Apple's next iPhone reveal much bigger than usual. Whether the company decides to call its next handset the iPhone 6 or iPhone 5S, many analysts think Apple needs to show off some killer new features with iOS 7 in order to keep pace with its rivals.

In the past, some have speculated that Apple will unveil a new mobile wallet with near-field communication technology, and now we're hearing about a rumor that indicates the iPhone 6 / 5S, alongside the redesigned iOS 7, will include full HD FaceTime video calls over a 4G network.

The rumor comes courtesy of iOS Doc, which claims an "Apple insider" as their source. The site said the same source predicted the new phone will include a 2-megapixel full HD front-facing camera, and now the source is hinting it'll be used for FaceTime.

"We heard again from our Apple insider and he revealed to us that Apple has even more goodies for us," iOS Doc reads. "According to him, the iPhone 5S will be capable of FaceTime full HD video calls over 4G LTE networks, and that the new feature will be an integral part of iOS 7. Of course, the iPhone 5S will be the only Apple device that will support full HD FaceTime calls over, as it will be the only one in the line-up to have a camera with 1080p capabilities."

This more than likely won't be the only new feature that Apple reveals with iOS 7 and the iPhone 6 / 5S, especially considering that the new OS is undergoing a completely revamped redesign. At this stage in the smartphone wars, though, it's become increasingly difficult to differentiate devices through simple specs alone, so it's fair to say that full HD FaceTime, while cool, won't be enough to convince many people to swing for a new phone or make a switch from Android. Perhaps as part of a suite of upgrades it can get the job done, so we'll just have to wait and see what Apple decides to showcase when it takes the lid off its new creation.