Fifth iPhone expected to be launched by Apple

Apple is expected to launch the fifth version of its best-selling iPhone today, the BBC News reported.

Doubts surround how different the iPhone 5 will be to its predecessor though some do expect big changes.

The launch will be hosted by Tim Cook, now Apple's full time boss following Steve Jobs' retirement in August.

As ever with Apple launches, exact details of product features will not be known until the event. Expert opinion is divided with some expecting significant changes.

"We're expecting a flagship, high tier product to cement the iPhone's position as the must-have device," said Ben Wood, director of research at analysts CCS Insight.

Gadget site Gizmodo took a different line and said there was only a 10% chance of seeing a new iPhone. Instead, it said, the iPhone 4S will be the new model and it will be cheaper than its predecessor.

Others say the cheaper model will be aimed at Asia, one of the few places where the smartphone has room for growth.

Rumours are also circulating that Steve Jobs will make a cameo appearance even though Cook is expected to be the launch compere.

The event is the first since Cook became official head of Apple. Before now he was an interim boss who oversaw day-to-day running of the company when Jobs was on sick leave.

The iPhone 4 debuted 15 months ago and the hiatus between that launch and today marks one of the longest periods without a new model in the history of the device. All previous versions, bar the first, have been unveiled in June.

Wood said this might reflect the complexity of the task Apple set itself when getting the iPhone working the iCloud service. This acts as a network-based backup and synchronisation system for Apple's smartphones and tablets.