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White Spaces Primer

Overview
In the United States, the private or commercial use of radio frequency spectrum is managed by the Federal Communications Commission (FCC). Wireless microphones, wireless personal monitors, and similar professional wireless devices are permitted to operate in several different parts of the spectrum; the largest of these is the UHF TV band, whose primary occupants are television broadcast stations.

As a result of the transition from analog to digital television (DTV), television stations in the U.S. can be spaced closer together in the spectrum – even on adjacent channels. This allowed the TV stations to fit into a smaller section of spectrum. Prior to the DTV transition, the spectrum from 470 MHz to 806 MHz was allocated to the UHF TV band. After the transition was officially completed on June 12, 2010, the spectrum allocated to the UHF TV band was revised to be 470 MHz to 698 MHz.

The remaining spectrum (698 MHz to 806 MHz, also known as the “700 MHz Band”) was reallocated for other wireless services. Some sections were reserved for use by public safety agencies, and other sections were licensed to commercial wireless service providers through a series of auctions conducted by the FCC. Wireless microphones and other professional wireless systems were prohibited from operating in the 700 MHz band after June 12, 2010 to prevent interference to the new licensed services.

Even after the DTV transition, some TV channels in each city remain unassigned to TV stations. After extensive study, the FCC decided to allow other wireless devices (including smartphones, computers, and similar products) to use these unassigned TV channels, often referred to as “white spaces.” Most of the operating rules for these “TV Band Devices” have been finalized, and the FCC may certify some of them for sale in 2011.

The prospect of consumer wireless devices sharing the spectrum used by wireless microphones and other professional wireless systems creates the potential for interference. Shure was deeply concerned about this proposal, and worked closely with the FCC and lawmakers in Congress to insure that a workable means for preventing interference to wireless microphones was included. In the form of comments to the FCC and correspondence with Congressional representatives, support for this position came from other wireless microphone manufacturers, the broadcast, theater, and live sound production community, audio equipment retailers and integrators, houses of worship, and end users at various technical levels. The final rules, adopted in September 2010, include measures that protect both small and large users of wireless microphones.

The FCC continues to seek ways to use radio spectrum more efficiently. The National Broadband Plan released in March 2010 outlined several possible approaches to increase the amount of spectrum available for wireless broadband in the U.S. In addition to consulting with the FCC and lawmakers in the U.S. on a regular basis, Shure is working with organizations such as the European Telecommunications Standards Institute (ETSI) and European Conference of Postal and Telecommunications Administrations (CEPT) that are studying the technical, operational, and regulatory issues that need to be considered to prevent interference to wireless microphones as TV band devices are deployed in other parts of the world.

Update!
On January 26, 2011, the FCC announced that they have made some progress in selecting administrators for the TV Bands Device database. This is the database that will dictate which TV channels TV band devices may use in a particular location, and in which wireless microphone users may register to temporarily protect the TV channels that they are using at a large event.

The FCC is "conditionally designating" ALL NINE of the companies that applied to be administrators back in November 2009. Rather than firmly selecting one or more of these applicants, the FCC will require all of them to attend "a series of mandatory workshops" at the FCC Laboratory "to ensure consistency and compliance with the rules." Each database will also be subjected to a 45-day "real-world trial" before final approval.

The nine "conditionally designated" administrators are:

Comsearch
Frequency Finder, Inc.
Google Inc.
KB Enterprises LLC and LS Telecom (who applied as a team)
Key Bridge Global LLC
Neustar Inc.
Spectrum Bridge Inc.
Telcordia Technologies
WSdb LLC

The first workshop was held on March 10, 2011.