White Spaces, 700 MHz Auctions, Other Frequency Bands
Shure has a strong message for our wireless microphone customers. "The sky is not falling," says Michael Pettersen, Director of Applications Engineering, whose department talks to hundreds of wireless microphone users every week. "Most people have heard only half of the story, and that half is often wrong."
While the UHF television band may become more crowded, it is not going away by any means. "Reports of the death of the UHF TV band have been greatly exaggerated," says Mark Brunner, Senior Director, Public and Industry Relations. "The UHF TV band has been, and will continue to be, the largest and best spectrum for wireless microphone users."
The FCC is in the middle of a multi-faceted reorganization of the UHF television band, stimulated by the future transition from analog to digital television broadcasting. The DTV stations will occupy a smaller section of the UHF spectrum (470 - 698 MHz) than is currently allocated for television broadcasting. The remaining spectrum (698 - 806 MHz) has been divided up into blocks. Some blocks have been or will be auctioned to companies that will use them to provide new nationwide wireless services, while others have been reserved for Public Safety communications.
Even with packing the digital TV stations into a smaller piece of spectrum, there will still be unoccupied channels in every market. These "White Spaces" are used by wireless microphones, in-ear monitors, and production intercoms. The FCC is considering the use of the "White Spaces" to deliver wireless broadband Internet service to consumer wireless devices.
The scale and complexity of this project has generated confusion among wireless microphone users, resellers, and even some manufacturers. Shure explains three points of misunderstanding: the difference between the "White Spaces" and the auctioned spectrum blocks, the fate of wireless microphones after the DTV transition, and the viability of other frequency bands for wireless microphone use.
No Auction For White Spaces
"The 'White Spaces' are not being auctioned," Brunner says. The auctions cover the spectrum from 698 MHz to 806 MHz, often referred to as 'the 700 Megahertz band.' "The 'White Spaces' will not be sold to Google, Microsoft, or anyone else," he says.
The Morning After
And what happens on "the morning after" the DTV transition? "Wireless microphones will not stop working on February 18, 2009," says Edgar Reihl, Shure's Technology Director, Advanced Development. "Any consumer device that the FCC allows to operate in the "White Spaces" must include circuitry and software that allows it to detect and avoid both TV broadcasts and wireless microphone signals." The FCC is currently testing this avoidance technology, and it is unlikely to authorize new devices unless they can adhere to these rigid rules and their performance is verified under real world conditions.
Some have engaged in wishful thinking that moving wireless microphones to other frequency bands can eliminate the risk of interference. "The 902 - 928 Megahertz and 2.4 Gigahertz ranges have been represented as some sort of 'spectrum lifeboats', but those 'boats' have holes in them," states Reihl. "The core UHF TV bands have much more usable spectrum available than the 902 MHz and 2.4 GHz bands, even after taking into account any new unlicensed devices that may exist in the years after 2009. More usable spectrum translates into more wireless microphone channels available to the user. Additionally, providing interference-free, high quality audio is even more challenging in these bands, where wireless microphones compete with other signals such as Wi-Fi and Bluetooth."
Adjusting Product Offerings
"When the timetable for the auctions became clear, we responded by transitioning our wireless products to new frequency ranges that are below the auctioned and Public Safety blocks," says Brunner. "Our premium UHF-R product was designed with the post-DTV RF landscape in mind. Its 60 megahertz tuning bandwidth is among the widest in the industry, offering maximum flexibility to large-scale wireless users."
Working Closely With FCC
Shure has been actively engaged with the FCC's Office of Engineering and Technology and with legislators in Congress since 2003. The Company has provided samples of its wireless products for use in FCC testing, submitted plans for field testing of interference effects, and has arranged meetings between FCC officials and representatives from broadcast networks, sports leagues, and other major wireless microphone user groups. "No one can definitively say how this will turn out," Brunner says. "The FCC has to iron out a lot of details before it makes any decisions related to new use of the 'White Spaces'."