Apple is set to unveil a new iPhone, presumably called iPhone 5, within hours at its headquarters in Cupertino, Calif.

The tech world is abuzz with various rumored specifications and features of iPhone 5, which Apple is releasing 15 months after it released iPhone 4 in June 2010.

It is more or less sure that iPhone 5 would come pre-loaded with iOS 5. It comes with 200 new features including improved notifications system, newsstand and iMessage. It will also feature new applications, such as the Reminders app and Newsstand, an application resembling Folders, and iBooks.

Apple is also supporting the new iCloud service that would allow wireless storage and access of music files on remote computer servers. iCloud will also store photos, apps, calendars and documents without storing them onto the phone's memory storage.

Following are the top rumored features of iPhone 5:

* Apple may unveil iPhone 5 with a slightly bigger screen size ranging from 3.7 to 4-inch to counter Android rivals.

* Deutsche Bank analyst Chris Whitmore has predicted that iPhone 5 will come in the unibody form that Apple uses in its Macbooks. The unibody construction method allows for a consistency of production and reliability by reducing many moving parts to one part. Also, it makes the product thinner and stronger.

* Generally, Apple products are known for their beautiful design and iPhone 5 would not be an exception. The new iPhone would adopt a teardrop design that is supposed to be slimmer and lighter than past iPhone models. The new smartphone, which may have an edge-to-edge retina display, would come with an aluminum plate casing rather than the current glass backing.

* iPhone 5 will have an 8-megapixel camera with LED flash capable of shooting 1080p high-definition videos and a better-than-VGA front facing camera. Currently, iPhone 4 has 5MP camera on the rear and a VGA camera on the front.

* iPhone is expected to have faster Internet speed as a new report claims that iPhone 5 would support HSPA+ networks that would provide faster Internet speed compared to its predecessors, Japanese blog Macotakara reported, citing a China Unicom executive's presentation at Macworld Asia.

* iPhone 5 is coming as an worldphone as it is rumored to feature a new SIM-less design with two to three internal antennas for CDMA and GSM compatibility. The smartphone is also rumored to sport a SIM card slot for other countries except the U.S., allowing users to insert any SIM card when traveling abroad.

* Apple is expected to fit a dual-core 1.2GHz A5 processor on iPhone 5 to compete with Android smartphones that are coming with 1.2GHz to 1.5GHz chips. A5 is the same chip that powers iPad 2.

* If Apple goes for a dual-core A5 chip, then it may need to boost the size of its RAM to at least 1GB. This would also support the rumored voice-control feature in iPhone 5.

* Speculations are rife that iPhone 5 may have voice-recognition features, inferred by the title of the invitation - Let's Talk iPhone. Piper Jaffray analyst Gene Munster said in a note to clients that the let's talk tag line is a less-than-subtle hint that Apple may be planning to deliver voice-recognition advances the company has been working.

* Another rumor making the rounds is that the next iPhone will be a fire-proof phone. Apple has filed a patent application for an advanced halogen-free flame retardant material which could be used in future Apple products. Patently Apple, an Applecentric blog, has reported that the new material will be integrated into the manufacturing of Apple products such as keyboards, mice, iPods, the iPad, cabling and more.

* Apple may add wireless charging feature in iPhone 5 to gain mass appeal, a move that could boost its battery life.

* Apple has a history of improving battery life with each refresh of iPhone. So, going by the past, we should see a better battery life on the iPhone 5 too.

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