Samsung Galaxy S4 rumoured release date on March 15 is further strengthened by a wireless charging accessory submitted to the Federal Communications Commission that is rumoured to be designed for Samsung's upcoming flagship smartphone.

The wireless charging pad is deemed to be 90 millimeters wide and will take advantage of the Qi wireless charging standard which means its compatible with existing smartphones such as the Windows Phone 8-toting Nokia Lumia 920, the HTC Droid DNA as well as the highly-popular Nexus 4 smartphone of Google and LG.

There are different Samsung Galaxy S4 rumours around. We are expecting Samsung to officially announce the Galaxy S4 on the 15th of March at a Samsung Unpacked event which is rumoured to be held in Moscow.

Earlier reports claimed that the upcoming Samsung Galaxy S4 will be released on March 15 weeks after the Mobile World Congress.

CNET sited a source close to the launch plans for Samsung allegedly stated that the Galaxy S4 will be unveiled at a later date. It is reported that Samsung does not want to share the spotlight with other smartphones that will be released at the tech event.

Samsung seemed to be planning an extravagant launch event for the successor of 2012's best-selling smartphone - Samsung Galaxy S3. Geeky-Gadgets claimed to have received a tip from a source working in a major retailer in the UK that Samsung's smartphone will launch sometime between April 15 and April 22. It will hit the Australian shores around May or June 2013.

Some of the rumoured specifications for the Galaxy S4 include a 5-inch FHD Super AMOLED 1980 x 1080 Flexible Display, 4G LTE connectivity, a 13-megapixel camera, 2-megapixel front camera, 2GB of RAM and Samsung's latest eight core processor, the Exynos 5 Octa that the company introduced at CES.

Some rumours claimed that the device will come with Androidv4.2.1 Jelly Bean out of the box. However, other rumours say that the device will run with Androidv5.0, Key Lime Pie.

Amidst the rumours, Samsung released no official comment yet on the rumours surrounding Samsung Galaxy S4.