The much-rumored Windows Phone 8 GDR2 update is reportedly slated to roll out in July, with the Nokia Lumia 920 as the first on the list.

Microsoft launched its Windows Phone 8 mobile operating system back in 2012 and no major software update rolled out so far. The OS got an update to Portico, or GDR1 (8.0.10211.204), but that was just a minor tweak. The GDR2 would come as the first major update.

According to Australia's largest mobile carrier, Telstra, the GDR2 update is expected to hit the Nokia Lumia 920 on July 8 and reach the Lumia 520, HTC 8X and HTC 8S a week later, on July 15.

The Nokia Amber update and the GDR2 will mean the same thing for Nokia users, although the Amber originates from Nokia itself. Microsoft, meanwhile, will add new features to all Windows Phone 8 devices as part of its GDR2 update. Such features will include widespread support for the previously Verizon-exclusive DataSense application, as well as support for FM radios.

Telstra's list does not offer a precise date for when all Windows Phone users worldwide will get the update. It does, however, offer some hints as to when carriers worldwide expect to get the update from Windows Phone device makers and Microsoft.

The update process may be more hectic and slower for the Android platform, but even Windows Phone updates still require testing and approval from individual carriers, as well as development from each Windows Phone device manufacturer.

Nokia's Amber update, for instance, will add many notable new features created by the Finnish company, including a persistent clock. It remains unclear at this point whether other Windows Phone 8 devices will get the same amount of new features besides those Microsoft will throw in with its GDR2 update.

HTC, the second-largest OEM for Windows Phone, did not detail its plans just yet, but it will make the update available to its users. Windows Phone is still trailing behind rival iOS and Android platforms, but it did manage to boost its share a bit. The update could convince more users to switch to Windows Phone 8, but Microsoft won't take the lead anytime soon, if ever.