The Wall Street Journal is reporting that Microsoft is working with hardware suppliers in Asia to test its own smartphone design that conceivably would compete with the iPhone and top-notch Android devices. The story cites unnamed component suppliers who claim they’re unsure whether Microsoft plans to actually go into mass production with the device.

Rumors of a “Microsoft phone” have circulated for years, and speculation has ramped up as the company moved into the tablet space with the release of the Surface. But while smartphones and tablets are often lumped together in the “mobile” industry, they are two very different markets: Smartphones are usually sold with lengthy service contracts and are often distributed through carriers themselves or big-box retail chains, while most tablets are Wi-Fi-only. So Microsoft would have to forge some strong carrier partnerships to bring a smartphone to market in a big way, which would surely irritate Windows Phone manufacturers like Nokia and HTC. I won’t be shocked if we see a Microsoft phone, but it would certainly be a risky move for the venerable software developer.