Google's next Nexus smartphone will soon hit the markets as the tech giant's stock of Nexus 4 has now officially gone down.

FCC filings of Nexus 5 had leaked online recently, while it has also been speculated that the smartphone would carry a new OS, Android 4.4 KitKat, reported The Verge.

As per reports, the device is expected to launch on 15 October. Hence, here is a roundup of all the rumors surrounding the gadget and its OS.

Nexus 5

Rumour has it that to build the device, the search engine giant has chosen LG; the same manufacturer for 2012's Nexus 4. Nexus 4 received good feedback from both consumers and media and that could be a reason why Google chose LG again.

Nexus 5 will carry a bigger display of 5-inch with a screen resolution of 1080p. The upcoming smartphone is speculated to support hosts of LTE bands and customers on AT&T, T-Mobile and even Sprint can also expect 4G connectivity. However, the Verizon customers might have to do without 4G.

Nexus 5 is expected to feature a non-descript design with a black, soft touch rear finish and the same landscape-oriented Nexus logo which appeared on Nexus 4. The service manual of Nexus 5 was leaked online which gave a list of specifications, including an 8 megapixel rear camera, a Snapdragon 800 CPU, 2GB of RAM and a 2,300 mAh battery.

The gadget is also rumored to support wireless charging and NFC but there is no possibility to expand the storage capacity on board. But the device will be available in 16GB and 32GB variants.  

Android 4.4 KitKat

Android 4.4 KitKat was initially in the rumours carrying the name Key Lime Pie but the company surprised everyone by giving the OS the name KitKat.  The unexpected change was made in the end, after Google realised that "very few people actually know the taste of a key lime pie." Google finally managed to secure rights to use the popular candy's name.

The search engine giant has been very secretive about Android 4.4 KitKat and has not revealed much about the update. But it did comment saying that its goal with KitKat is to "make an amazing Android experience available for everybody." Through which it has been predicted that Google's next mobile operating system update maybe designed for maximum compatibility across devices, which includes gaming consoles, smartwatches, laptops.

Some of the photos leaked shows the Nexus 5 running Android 4.4 KitKat, which showcased the transparent notifications and navigation bar, Google applications along with other preloaded apps. These photos were leaked by TuttoAndroid.

The photos also revealed that the all-black background has been removed and the new smartphone will sport a transparent look at the home screen. A shortcut icon for the camera has now been placed on the lock screen. It has also been revealed that Google has brought over some "always listening" function from the newly launched Moto X which will give access to Google Now and Google Search.  

There were another set of photo leaks by 9to5Google which revealed that the dialer and the status bar has been redesigned and it change colours, according to what's on the screen.