SAN FRANCISCO - Microsoft on Wednesday previewed its latest mobile operating system Windows Phone 8, a further step by the software giant to beef up its mobile efforts.

Joe Belfiore, Corporate Vice-President of Microsoft, introduces the Windows Phone 8 mobile operating system in San Francisco, California, June 20, 2012. [Photo/Agencies]

The mobile software, also codenamed Apollo, has a shared core of Windows NT kernel that powers desktop and laptop versions of Windows, said Joe Belifore, Microsoft's head of Windows Phone, at the Windows Phone summit in San Francisco.

The shared core means support for multi-core processors, from dual-core, quad-core to a possible 64-core in the future, enabling consumers to have more hardware options. Manufacturers will also be able to scale up and down in price and performance of the devices, and developers will have an easy transition from the PC system to working with the mobile platform.

Microsoft confirmed that there will be dual-core handsets initially this fall.

Windows Phone 8 also has support for Near Field Communication ( NFC) hardware, enabling users to make their smartphone a digital wallet.

Microsoft said the platform will provide users with a complete wallet experience, from credit and debit cards, loyalty and membership cards, to saved deals and "tap to pay."

The platform has support for Micro-SD card expansion of storage, allowing users to transfer music, photos and video, and even install applications. It also features support for three screen resolutions.

It also has a new start screen, which is similar to the start screen in Windows Phone 7 but allows users to scale the size of the live tiles to make their phone more personal.

Meanwhile, Microsoft announced voIP (voice over telephony) integration for Windows Phone 8, enabling Skype as well as any other third party voIP applications to integrate into the mobile system.

For consumers, this will provide a near seamless user experience as Skype and other voIP applications fully integrate into the Windows Phone dialer and contacts. For example, incoming Skype calls, which are treated like cellular communications, will appear as regular calls with standard phone features.

The software giant also demonstrated Internet Explorer 10 browser on Windows Phone 8. The mobile version of IE 10 will have a phishing filter and Microsoft's SmartScreen URL reputation system, warning users against malicious sites and phishing schemes based on data used across Windows systems.

The company also announced it would replace Bing Maps with Nokia's mapping technology. Nokia maps will bring support for offline maps and better global coverage of mapping data, it said.

According to Belifore, the new mobile operating system will be officially released this fall.

The preview of Windows Phone 8 is a further demonstration of Microsoft's mobile efforts after it introduced its Surface tablet earlier this week at an event in Los Angeles.