The Lumia 920, Lumia 820 and Lumia 620 are all set for an update very soon. No new features will be introduced, but the update is expected to improve overall performance and stability of all three devices.

Al three handsets are Nokia's only Windows Phone devices on the market right now, while a fourth, the Lumia 720 is scheduled for launch very soon.

"This software, version 1232.5957.1308.00xx, includes further performance and stability improvements, enhancements to display stability during a call, and improved automatic display brightness adjustment.In addition, Nokia Lumia 620 has some new software in the pipeline. This software, version 1030.6407.1308.00xx, will include improved touch behavior and enhancements to system stability and camera picture quality, such as corrected camera exposure when the flash is used in bright light conditions," says Nokia blog

Nokia kicked things off last year with its first Windows Phone 8 device, the Lumia 920. With its 4.5-inch OLED screen, dual core processor, 1GB RAM and 8.7-megapixel PureView camera, the device quickly became the top selling Windows Phone 8 handset despite only launching on a single carrier in the United States.

The device that follows the Lumia 920 is the Lumia 820 mid-range handset. It packs the same CPU power and RAM size as its bigger brother, but lacks a plethora of high-end features that set the Lumia 920 apart from other smartphones. It went on to launch on multiple carriers worldwide, although at this moment in time, it is not certain how well the handset is performing.

Finally, Nokia launched the Lumia 620, a low-end Windows Phone 8 device that packs great performance into a small frame. It's the cheapest Windows Phone 8 device yet, one that should be able to top the Lumia 920 in overall sales worldwide.