Nokia Lumia 1520
GDR3 update to feature, screen orientation lock, customised sounds for notifications, quad-core chipset support and others. (Twitter: EvLeaks)Twitter: EvLeaks

Screenshots of Windows Phone 8 GDR 3 update, also known as Bittersweet Shimmer update have been spotted on Nokia Lumia 520 model. The update is yet to be announced officially by Nokia. The new leak trails the images of the same update seen on Nokia Lumia 920 model last week on Craiglist.

The images seen on WinPhone Viet, a Vietnamese Windows news website show the "extra+info" section under settings option in Lumia 520 with a manufacturer name stated as "RM-914_im_india_443." This however confirms the rumors of the update being tested in India.

The update is likely to be rolled out with the launch of Nokia's rumored Phablet - Nokia Lumia 1520, which is said to arrive on Oct. 22.

WP8 GDR3 update is expected to support quad-core based chipsets along with high resolution displays. Other features to arrive with the update include orientation-lock and driving mode, which disables certain handset features while driving. The update is also expected to support close applications from the multi-tasking view along with customized sounds for texts, emails, messages and reminders, according to Geeky Gadgets.

Since Nokia is in the process of rolling out GDR 2 update for Lumia models, which is scheduled to reach all Lumia devices by the end of September, the GDR 3 update seems quite far from being announced this year.

In related news, Nokia's much hyped Phablet, Nokia Lumia 1520, codenamed Nokia Bandit, was spotted online featuring a 20 megapixel Carl Zeiss camera in its back panel. Along with the camera confirmation, it has also been confirmed that the model is set to come with a 4G LTE connectivity, which can be assumed from the 4G logo imprint at the bottom part of the panel.

Other features rumored for Nokia Bandit include a 6in 1080p HD screen display, latest Qualcomm Snapdragon 800 processor with GDR3 update, 32GB in-built storage with a microSD card slot and to back all these features, a powerful 3400mAh battery.