Even as rumors about Microsoft's premium Lumia series Windows 10 mobile devices continue to flood the Internet, a recent report revealed key details of the Redmond-based tech giant's original brand - the Surface phone.

According to IB Times, Microsoft's upcoming phone has been code named Project Juggernaut Alpha, and it will supposedly be marketed as Surface Mobile. Moreover, several reports suggest that the device will be available sometime at the end of 2015 or early on 2016.

A leaked screenshot obtained by WMPU suggests that currently the Surface Mobile is being tested internally with Windows 10 Mobile preview build 105140. Having been tipped by its anonymous source, WMPU has also shared the device's hardware and software details.

WMPU suggests that Microsoft's Surface Mobile will sport a 5.5-inch screen rendering 1440 x 2560 pixels resolution. It is expected that the screen will be protected by Gorilla Glass 4.

There are rumors that the upcoming Surface Mobile will be powered by Intel's Atom x3 chip (code named SoFIA), which features a quad-core processor with 64-bit computing.

Intel's Atom x3 was announced during the Mobile World Congress in Barcelona in March and officially unveiled in April. It belongs to the economical System-on-chip and will be available in the 4G LTE and 3G version. In fact, the Atom x3 would be paired with 4GB RAM (3GB RAM for low-end, but 4GB for premium devices).

As far as the camera section of the Surface Mobile is concerned, it is expected that the upcoming smartphone will sport a 21-megapixel PureView Zeiss sensor on its rear side alongside an 8-megapixel wide-angle Zeiss camera sensor in the front.

Surface Mobile will run Windows 10 Mobile right out of the box. Apparently, Microsoft will not offer a lower storage variant, as the specifications sheet lists 64GB and 128GB storage options only along with MicroSD card support for additional space up to 256GB.

The Surface Mobile is also expected to feature support for Surface Pen, something similar to the S Pen in the Galaxy Note series uses. Other features of the phone include USB Type-C and wireless charging.

As regard to the build quality, Surface Mobile is likely to have a unibody made from aluminum and magnesium. However, since Microsoft is yet to confirm any detail regarding the Surface Mobile, these specs should be considered as mere speculations.