"The rules adopted today," the FCC said, "will allow for the use of these new and innovative types of unlicensed devices in the unused spectrum to provide broadband data and other services for consumers and businesses. The rules represent a careful first step to permit the operation of unlicensed devices in the TV white spaces and include numerous safeguards to protect incumbent services against harmful interference."

How quickly the benefits of what proponents call "Wi-Fi on steroids" will be available to the public is uncertain.

"It is difficult to predict when products will move into the marketplace," said Ginny Terzano, a spokesperson for Microsoft. "Companies need to review the rules closer and there are a multitude of factors that will determine when a product will be developed. But generally we might start seeing the benefits of yesterday's FCC ruling with products in the marketplace within 18 to 24 months or so."

Positive Reactions

The FCC's decision was praised by both Microsoft and Google, which have been lobbying hard to open up white space. Although the two companies are increasingly competitive on a variety of fronts, they teamed up to lead a broad coalition of tech companies and public-interest groups advocating for the change under the banner of Free the Airwaves.

"This is a clear victory for Internet users and anyone who wants good wireless communications," said Google cofounder and president of products Larry Page in a company blog.

Craig Mundie, Microsoft's chief research and strategy officer, agreed. "Today's vote makes possible new ways to connect people and devices to each other and to Internet-based services, helping boost American productivity," he said. "And it will create opportunities for American companies to remain at the forefront of technological innovation worldwide, helping to create jobs and economic growth."

Careful Implementation

The FCC said its ruling is designed to protect existing transmissions. Any devices designed to access white space Wi-Fi, the commission said, "must include geolocation capability and provisions to access over the Internet a database of the incumbent services, such as full-power and low-power TV stations and cable-system headends, in addition to spectrum-sensing technology." In addition, each white-space device must be able to detect wireless microphone transmissions, a requirement to address the concerns raised by high-profile entertainers such as Dolly Parton.

All devices will be required to obtain certification from the FCC Laboratory that they meet the commission's requirements before they can be marketed to the public, and the FCC made it clear that it will police television white space carefully.

"The commission will closely oversee and monitor the introduction of TV white-space devices," it said. "The commission will act promptly to remove from the market any equipment found to be causing harmful interference and will require the responsible parties to take appropriate actions to remedy any interference that may occur."