GOVERNMENT engineers in the United States are winding up lab tests that will help determine whether Google's plan to beam Internet searches over vacant airwaves would interfere with digital television signals.

The findings will help regulators decide the future use of intervals between TV channel frequencies. The largest technology companies are urging the US to give mobile phone users free access to those airwaves, known as white spaces, Bloomberg News said.

Google and Microsoft propose using these spaces to expand the US$24.5-billion market for mobile Web services. Google co-founder Larry Page said the unused frequencies could become "Wi-Fi on steroids," blanketing the nation with high-speed Internet access. Broadcasters say this would disrupt TV reception.

"This is a very contentious proceeding," said Federal Communications Commission Chairman Kevin Martin, whose agency will decide the matter.

Wireless

"What we're doing is different. It's not testing a consumer product. Rather, it's testing prototype devices to help us set the rules at the beginning."

Sports organizations, musicians and performers, who use wireless microphones operating on white-space frequencies, are also fighting the proposal.

The FCC is evaluating devices submitted by proponents of the plan that are designed to prevent interference. If the technology works, the FCC could adopt rules this year to allow wider access to the airwaves, Martin said.

The US last year ranked 15th in percentage of population subscribing to a high-speed Internet service, down from 12th in 2006, said the Organization for Economic Cooperation and Development.

Page said the plan would help the US catch up because the airwaves could form a free national wireless broadband network.

But David Donovan, president of trade group Association for Maximum Service Television, said allowing unlicensed devices to use those channels would cause interference for millions of viewers.