Details about the future design of Windows Phone-based handsets have been acquired by TechRadar, outlining Microsoft's potential plans for its growing mobile operating system.

Last week a video appeared online showing a range of new form factors which could be employed on next-gen Windows Phone handsets. This could include scaled-down miniature mobiles along with mid-size tablets and even models packing physical keypads.

Windows Phone executive, Albert Shum, went further than simply confirming or denying the veracity of the video and actively showed a slide to journalists attending Nokia World, which showed six different device types planned by Microsoft.

Mr Shum also asserted that Windows Phone would be a single piece of the puzzle in the future, not the only mobile platform or iteration promoted by Microsoft.

The slide shows that Windows Phone mobiles will sit alongside tablets and desktop computers, implying the idea of an interconnected yet distinct ecosystem of devices.

Windows 8, the full desktop operating system currently still in development at Microsoft, is likely to sit on the larger tablets and computing devices. However, Windows Phone Apollo, or Windows Phone 8, could find its way onto five inch pseudo-tablets, to help bridge the gap between smartphones and the lucrative market created by the iPad.

A five inch Windows Phone handset would be pitched directly against something like the Android-based Samsung Galaxy Note and might even encroach on the market of the Amazon Kindle Fire.

Admittedly, there are already large Windows Phone models on the market, with the HTC Titan leading the way with its 4.7 inch display. However, the relatively low maximum screen resolution of 480x800 enforced by Windows Phone 7.5 Mango, would prevent tablet-aping features from really taking hold, so the Apollo update will be necessary before such devices can arrive.

Microsoft has been surprisingly candid with details about the upcoming developments for Windows Phone, given that major rival, Apple, remains tight lipped about the next iPhone handset until the day of launch.

The obvious reason for this is that Apple does not really need to set the hype train in motion at all as millions clamour for its latest products, while Microsoft has to work hard in order to establish Windows Phone as a valuable platform and a viable alternative to the iPhone. By diversifying, it could make up ground, but most had assumed that physical keypads were all but dead.