White Spaces Relief
We may not have heard the last word in the ongoing debate over wireless microphones and so-called next-generation white spaces devices. But the FCC's latest word is a good one.
Shure UHF-R Wireless Microphone Systems were used for the musical "Thriller Live." Shure has been active in lobbying the FCC for consideration of wireless microphone systems during deliberations about white spaces.
Credit: Photo Courtesy of Shure
There are a couple of possible reactions to the decision by the Federal Communications Commission last month regarding wireless devices that operate in the white spaces spectrum, which had been freed up by moving TV channels from their traditional frequency band. There's the way Reuters put it, which was that "U.S. regulators paved the way ... for new, faster wireless devices by opening unused television for mobile broadband use." Or there's the point of view of AV companies that have monitored the white spaces issue for years, such as Shure, which said that it "applauded a decision by the [FCC] to protect wireless microphone users from interference from 'white space devices."
It sounds like the FCC made everyone happy with its latest order, issued Sept. 23.
"It's clear that the FCC carefully considered the needs of wireless microphone users while crafting this order," said Sandy LaMantia, president and CEO of Shure. "The reserved channels will provide a safe harbor in which musicians, small theaters, houses of worship, and businesses can operate their wireless microphone systems without interference from new TV band devices."
Nearly two years ago, the FCC issued an order governing the use of white spaces by nextgeneration smartphones, computers, and other products. Many in the AV industry recognized some unresolved legal and technical issues with this directive. The new order appears to have addressed most of these concerns.
A nagging question from the previous order focused on how new wireless devices would avoid interfering with existing or incumbent users of the TV bands—which included TV stations, wireless microphones, wireless in-ear monitors, and wireless production intercom systems. The new order establishes a set of operating protocols that will enable small and large users of wireless microphones to operate without interference from new devices through reserved channels, a geolocation database, and other means.
According to an analysis by Shure, which followed on the heels of the FCC's ruling, the majority of wireless microphone users can operate in reserved TV channels that are off-limits to white spaces devices. The 2010 order reserves at least two TV channels in each market for wireless microphones. Of course, because occupied TV channels vary by market, the reserved channels will vary, too. There will be other TV channels that won't be explicitly reserved, but they will be off-limits to new wireless devices and therefore available to wireless mics.
The new order also strengthens the provisions laid out by the geolocation database program. In 2008, the FCC introduced a system whereby wireless microphone operators for large events could register in a database. Then, anyone wanting to operate in white spaces devices would need to get a list of available channels in that location before transmitting. Wireless mic operators have to register at least 30 days in advance of an event and certify that it will be operating six or more mics.
Under the new order, portable white spaces devices can't transmit inside an exclusion zone, which is 400 meters around a registered event. But stay tuned—even after the latest order, the FCC hasn't decided on a database administrator and hasn't fi nalized the procedure for registering.
Also notable in the new order: Spectrum sensing for new portable wireless devices is now optional, whereas in 2008 it was required. Built-in spectrumsensing technology was supposed to help detect and avoid TV stations and wireless microphones not in the geolocation database. Device makers bristled at the cost of adding this technology to their products. They can still use spectrum-sensing instead of the geolocation database (which must be polled every 24 hours), but they're not required to.
Shure officials have advised users to start checking out TV channel assignments in their markets and figure out which will be reserved. Analysts say it could be two years before widespread commercialization of white spaces devices. But better to prepare now.