A renewed lobbying push by Google to utilize the spectrum for the Internet has run into strong opposition from powerful broadcasters.

The National Association of Broadcasters (NAB) has come out against a proposal that the tech giant submitted to the Federal Communications Commission (FCC) Monday. Under the plan, the FCC would institute more protections for televisions and wireless microphones if portable devices began using “white spaces” — unused parts of the spectrum that could otherwise relay radio and TV signals — for broadband access.

“Portable, mobile personal device operation in the same band as TV broadcasting continues to be a guaranteed recipe for producing interference and should not be allowed under any circumstances,” said Dennis Wharton, an executive vice president for NAB, in a statement late Monday.

Wireless microphone users share similar worries that the devices’ signals would jump over into their broadcasting bands and cause performers’ audio equipment to malfunction.

Members of the Microphone Interests Coalition, an alliance of audio equipment users, have concerns with the proposed white space devices and weighed in against the proposal as well.

In a statement Tuesday, Pete Fisher, vice president and general manager of the Grand Ole Opry , said: “Google’s recent proposal that would require existing spectrum users to purchase yet-to-be-developed spectrum ‘jammers’ is not only speculative, it is unproven and untested technology.” The Opry is part of the Microphone Interests Coalition.

On the other side of the debate, tech companies such as Microsoft and Dell have sided with Google. They see white spaces as prime real estate to expand Internet access for consumers. That part of the spectrum provides superior quality for broadcasting and could be a boon to rural America, which is underserved by broadband providers.

Richard Whitt, Google’s Washington telecommunications and media counsel, said in a conference call Monday that white spaces are a “once in a lifetime opportunity” and a “tremendous, untapped potential resource.”

In its Monday letter to the FCC, Google proposed some protections to assuage the doubts of NAB and others about the portable devices. Under its proposal, a white space device would not transmit on a certain channel unless it receives an “all clear” from a database of licensed transmitters or from a device located nearby that has access to that database. In addition, beacons in wireless microphones would block transmissions from white space devices if they moved into their signals. Google also offered a “safe harbor” to audio manufacturers, saying that certain channels would be reserved for microphones and off-limits to the portable Internet devices.

Google also said it plans to use its much-heralded open-access software, known as Android, for the white space devices. Still in development, Android would allow consumers to download a variety of applications for a multitude of mobile gadgets, such as cell phones.

Google’s proposal is similar to one submitted by Motorola last fall. But Wharton and NAB do not think it solves the problem.

“We are pleased that Google now seems to realize that spectrum sensing alone won’t protect viewers against interference from unlicensed devices. Unfortunately, simply adding geo-location and beacon sensing does not mean that mobile operation is suddenly feasible,” said Wharton in his statement.

“It’s unfortunate that NAB apparently would rather try to score political points than do what’s best for American consumers. Google offered its proposal as a good-faith, constructive measure, and in the best spirit of industry compromise,” said Whitt in response to the broadcasters.

For his part, Fisher disagreed with Google’s claim that the beacons would provide protection for thousands of live entertainment venues such as his.

The FCC has become a focal point of lobbying for both sides on the debate because it is considering a ruling on white spaces.

But no ruling is expected until the commission is done testing white space devices. The commission started one round of testing in the spring of 2007. A prototype by Philips performed well, while another by Microsoft did not. In February this year, another Microsoft model also had problems during FCC tests.  

In October 2007, the FCC announced it was conducting a second round of testing for the devices, including field tests. That round was to be finished by mid-March, according to the commission’s original estimates, but is still under way.

Meanwhile, Capitol Hill has also taken notice of the battle over white spaces. Seventy lawmakers have written to the FCC to take the side of broadcasters, according to NAB’s count.

But another trade association, the Wireless Innovation Alliance, has initiated a counter-effort. Google and 14 other tech companies founded the group in December 2007. The WIA has called upon more members of Congress to back the white space devices. Nineteen lawmakers have already written to the commission supporting the devices.

Jim Snyder contributed to this report.