Sprint launched its 4G network some 18 months ago. So far, it's been used primarily for hotspots and USB modems. What it hasn't been used for is actual mobile devices. Apparantly, that's about to change.

Forbes Magazine is reporting that Sprint is telling them they will be selling their first 4G phone by summer, a few months before schedule.

Sprint's 4G network is a joint venture with Clearwire Corp. This is the WiMax network that got lots of press a couple of years ago when it was still in the blue sky phase.

4G is up to 10 times faster than 3G. Apparantly, it's already being used in some industries like healthcare. It's ideal for streaming medical images for telemed purposes and training, for example.

Verizon has its own version of 4G that is expected to debut later this year, as well.

So what kind of phone can we expect this summer? Sprint is still not saying. But, the leaked screen grabs floating around the mobile tech blogs all show what appears to be an Android handset.