Opening the White Space would enable the use of mobile devices on the empty spectrum between TV channels.
Introduction
In between TV channels, there is a significant amount of valuable, unused spectrum. This empty spectrum is known as White Space. The FCC is currently considering the most efficient use of the White Space. The spectrum has the same propagation characteristics as the frequencies used for DTV transmission, meaning signals will be able to travel over long distances and through walls. As a result, this spectrum has the potential to help solve many of our countries broadband woes, such as:
The lack of rural broadband penetration. Wi-fi technology can be used to bring broadband to densely populated areas but is useless over long distances. Opening the White Space could allow wi-fi hotspots to be large enough to service rural areas.
The difficulties of bringing broadband from the curb into the home. It is enormously expensive to lay wire into every home. Opening the white space could allow Internet service providers to bring broadband into the home without laying costly wires.
However, TV licensing is done on a regional basis, causing the location of empty channels to vary from region to region. Only mobile devices that are “intelligent” enough to know when and at what spectrum frequency they can transmit so as not to interfere with other broadcasters, will provide the economies of scale necessary to prompt device manufacturers to innovate. In order to ensure the spectrum is used most efficiently, the FCC must adopt rules that prevent TV interference without halting the potential benefits of unlicensed mobile devices.
Timeline
October 2006: FCC issues a First Report and Order to examine the issue of opening the White Space. The public interest community filed comments at the FCC asking them open the White Space for unlicensed mobile devices in order to ensure an efficient use of the spectrum.
March 2007: FCC’s Office of Engineering Technology (OET) issues a report measuring the interference rejection capabilities of DTV receivers.
July 2007: OET reports results of test evaluating potential interference from unlicensed devices to TV and other radio services. Microsoft and Phillips Electronics both submitted smart radio prototypes with spectrum sensing technology. OET found that the Microsoft device was unable to detect DTV signals, but the Phillips device was moderately successful.
