More than 100 corporations, trade associations and public interest groups are worried that white space spectrum could become a casualty of the showdown between the House and Senate over the payroll tax cut extension bill.

The organizations sent letters yesterday to Democrat and Republican leaders in both houses asking them to steer clear of provisions that would eliminate the unlicensed airwaves.

"It is particularly critical that some of the ‘beachfront' spectrum located in the television bands remain available for unlicensed services, which are driving innovation, promoting rural broadband deployment and creating new services in the wireless ecosystem," the Wireless Innovation Alliance wrote in a note sent Monday.

The Wireless Innovation Alliance led a petition signed by more than 100 parties ranging from Google to the Wireless Internet Service Providers Association.

Public Knowledge organized a separate letter signed by the New America Foundation, Media Access Project and a number of other groups.

The letters also urged lawmakers to abandon plans to restrict the FCC's ability to govern spectrum auctions.

White space spectrum, the vacant airwaves between television channels, was opened by the FCC for unlicensed use in September 2010. The release of the spectrum paved the way for technologies like so-called Super Wi-Fi, souped-up routers using white space bandwidth to increase speeds and coverage.

Legislation circulating in the House and Senate does not currently contain language that would affect white space spectrum, but the groups are concerned that lawmakers will revive a December proposal to repack television stations into a smaller swath of spectrum, reducing the number of empty channels available for white space devices and rendering the technology unviable.

House Republicans riled by the FCC's net neutrality regulations and opposition to AT&T's merger with T-Mobile USA have repeatedly targeted the agency with proposals that would strip it of its ability to impose conditions on mergers and spectrum auctions and place burdensome limits on new regulations.

A recent version of the House payroll tax cut extension bill included language that would strip the agency of its authority to control spectrum auctions.

Specifically, the provisions prevent the FCC from excluding auction bidders for reasons other than "technical, financial and character qualifications," and they stop the agency from imposing net neutrality conditions or requirements that a licensee provide wholesale access to its network.

Negotiations over the payroll tax cut extension bill are still ongoing, and it is unclear what the legislation will contain when it hits the president's desk.