Timeline: Apple iPhone to iPhone 5

New Delhi: The expected iPhone 5 would actually be the sixth iPhone model.

Although Apple hasn't announced a name for its next iPhone — or even confirmed that one is coming — a "5'' in the shadow of an invite for a company event Wednesday suggests that it will be the iPhone 5.

Here are Apple's iPhone releases since its debut in 2007:

Here are Apple\'s iPhone releases since its debut in 2007:

— iPhone, June 29, 2007, starting in the US (announced January 9)

— iPhone 3G, July 11, 2008, starting in the US, Australia, Austria, Belgium, Canada, Denmark, Finland, France, Germany, Hong Kong, Ireland, Italy, Japan, Mexico, Netherlands, New Zealand, Norway, Portugal, Spain, Sweden, Switzerland, and the UK (announced June 9)

— iPhone 3GS, June 19, 2009, starting in the US (announced June 8)

— iPhone 4, June 24, 2010, starting in the US, France, Germany and Japan and the UK (announced June 7).

— iPhone 4S, October 14, 2011, starting in the US, Australia, Canada, France, Germany, Japan and the UK (announced October 4).

— iPhone 5, likely to be announced today.

The new iPhone 5 has to be more than just another smartphone as it carries the weight of Apple's future on its slim frame.

Five years after the first iPhone upended the mobile industry, analysts say Apple is looking increasingly defensive as Samsung Electronics and other rivals have been first to market with phones that sport bigger screens or run on faster wireless networks.

Apple will try to close that gap on Wednesday with the unveiling of the newest iPhone, which is widely expected to offer 4G wireless technology for the first time, and a 4-inch display, up from the current 3.5 inches.

But it remains to be seen if Chief Executive Tim Cook has any surprises up his sleeve, and if he will show off any technological breakthroughs that can put the iPhone 5 head and shoulders above the competition.