Microsoft is preparing the first major update for Windows Phone 8 since its release that will introduce a range of new features, along with fixes to certain issues.

The Verge is reporting sources as saying that the update, dubbed Apollo Plus, won't be the next major version of the software, but more of an incremental improvement.

It is likely to bring features such as Virtual Private Network (VPN) support and a Wi-Fi fix which will allow connections to always remain on, according to The Verge.

VPN is a widely supported feature on Windows' desktop operating systems, such as Windows XP, Vista, 7 and 8. However, it has been absent from latest Windows Phone 8 for smartphones and tablets computers.

VPN allows corporate users to connect their devices securely to work communications systems across the Internet.

In June ZDnet reported Microsoft officials as saying that Microsoft had decided against including VPN functionality in the Windows Phone operating system, despite having included it in the Windows Phone OS' predecessor, Windows Mobile.

At the time the company said it had decided instead to rely on things like Secure SSL to address this need as they considered it "a better, light-weight approach" to providing this kind of functionality in the new age of smartphones.

Aside from the VPN feature and Wi-Fi tweaks, some audio improvements will also be introduced in what many are reporting as a minor update.

Windows Phone 8 was only released in October, to coincide with the launch of the new Windows 8 OS, which is itself revamped to blend seamlessly with smartphone, tablet and desktop computers.

The Nokia Lumia 920 and Lumia 820, along with HTC's 8X were the first phones to feature Windows Phone 8.

Users of those devices will be able to download updates over-the-air using wireless internet connections - a change from the previous OS that required users to plug devices into PCs to get similar updates.

Microsoft hasn't commented on the updates and The Verge speculates that it will likely be launched during Mobile World Congress in February 2013.

Meanwhile, there is no word as to how many of the updated Windows Phone 8 features, such as VPN, will make it to the anticipated Windows Phone 7.8 expected to be released later this week. That update is for users running Windows Phone 7.x devices.