White space, in a communications context, refers to underutilized portions of the radio frequency (RF) spectrum. Large portions of the spectrum are currently unused, in particular the frequencies allocated for analog television and those used as buffers to prevent interference between channels.
In the United States, frequency allocations in the RF spectrum are made by the Federal Communications Commission (FCC). In November 2008, the FCC voted unanimously to make unlicensed portions of the spectrum available for use. At that time, at least three-quarters of the spectrum allocated for analog television was unused. These frequencies will become available once the changeover to digital television is complete in February 2009.
White space allocation is expected to stimulate development of wireless technologies and services. According to Google co-founder Larry Page, white space operation will be like "Wi-Fi on steroids," because the signals in that portion of the spectrum have much longer ranges than those currently used for Wi-Fi. The increase in range means that fewer base stations will be required to give better coverage; that increased efficiency, in turn, should yield better service at lower costs. Signals in the white space range can also penetrate through solid objects better, which should yield more reliable service.
Opponents of white space allocation have argued that it could lead to unexpected instances of disruptive and potentially dangerous interference between different services using the same frequencies at the same time. The FCC is testing white space devices designed to operate in the newly available frequencies to ensure that they will not cause interference.
According to the FCC, wireless microphones and other low-power auxiliary stations will be able to continue to operate in bands below 700MHz.
Learn More About IT:
> For the New York Times, Matt Richtel reports on the FCC's decision to make white space spectrum available.
> Hugh Carter Donahue provides the background on white space policy.
> Larry Page hails 'A vote for broadband in white spaces.'
> Stephen J. Vaughn-Nickols says the FCC's decision opens a new era for broadband.
> The Association for Maximum Service Television offers arguments against white space allocation.