Google's Android mobile operating system may be the face of the show at the world's biggest wireless fair next week as the firm expects many companies to demonstrate their prototype devices using its Android OS.

However, Google said the prototypes shown at the Mobile World Congress in Barcelona will not be indications of the devices consumers will ultimately see.

Some will be an early prototype device that we used in the past to test the platform, others may simply have circuit boards, said Barry Schnitt, Google spokesman.

Google may start selling the Android mobile operating system commercially in phones and services starting the second half of 2008.

UK's ARM, a chip designer is expected to show one of the Android prototypes while Deutsche Telecom's T-Mobile and Taiwan's High Tech Computer plan to sell phones this year based on Android.

Several other companies showed much support for Google's new operating system, including Motorola Inc and Texas Instruments Inc, a wireless chip company.