The FCC Wants to Eliminate More of Your Wireless Frequencies in 2015
The use of wireless audio systems, including wireless microphones for artistic performers and onstage announcements, and intercom systems needed to keep complex live-event productions running smoothly, has been steadily increasing as business picks up in the wake of a lengthy recession. As per Strategic Meetings Management, a sector analysis by market researcher Aberdeen Group, analysts are estimating that total U.S. spending on corporate meetings and events is expected to rise by 20 percent over the next two years, Unfortunately, it’s doing so just as wireless spectrum -- the radio frequencies used for wireless communication -- is about to undergo yet another contraction that will further restrict the wireless playing field for professional users.
In 2010, the Federal Communications Commission put the RF range between 698 MHz and 806 MHz -- aka the White Spaces, the buffer frequencies between television stations that became available after the U.S. transitioned to digital television in 2008 -- up for auction. Bidders included consumer electronics giants like Verizon and Google who sought more operating spectrum for their consumer wireless mobile devices. Summarily evicted from these frequencies were many non-emergency professional users such as broadcasters, theatrical productions such as Broadway musicals, and large-event productions such as corporate product introductions. Large houses of worship were also affected by the sweeping sell-off of this particular batch of RF, which was part of the spectral sweet spot for both effective operating range and sonic performance.
Sometime in mid 2015, the FCC plans to put another sizeable chunk of RF spectrum out for auction, this time in the 600-MHz range -- the same range that most professional wireless users were pushed into after the last spectrum auction. This means that users will have twice been compelled to invest in new wireless systems that comply with newly rearranged spectrum availability in the space of a few years. For a single mid-sized theater with 16 channels of wireless microphones, that could cost as much as $48,000. Larger venues with more wireless channels would pay substantially more. Perhaps worst hit would be equipment rental companies, who investments in thousands of channels of wireless microphones and intercoms could be valued in the millions of dollars. Wireless systems manufacturers are already working on developing systems that are optimized for the 500-MHz range, but with each dispossession into a lower frequency band, the technical challenges become more difficult.
“Six hundred to 800 MHz was where we had optimal [sonic] performance and tunability” -- the ability to precisely shape RF filters for maximum range and best sound quality, says Karl Winkler, director of business development at microphone manufacturer Lectrosonics. “As we move into lower frequencies, we have to develop better frequency filters. But it’s still a part of the spectrum that’s not as easy to work with as what we had before.”
For instance, lower frequencies require longer antennas. Older wireless transmitter models made for the 600-750 MHz range needed antennas that were about 3.5 inches long; a bodypack transmitter intended to work in the 500-MHz range needs one that’s closer to 5.5 inches in length. Taking that down to about 450 MHz -- a destination that some manufacturers fear is the next step in the seemingly relentless sell-off of spectrum -- would require a 6.25-inch antenna. Addressing the changes that conforming to the needs of another area of RF spectrum compels manufacturers to allocate more of their revenues to R&D and testing,
But if migrating to new spectrum is costly for manufacturers, it’s perhaps even more so for their customers: after having had to purchase new wireless systems that are designed to work in the 600-MHz range in the wake of the first big spectrum reallocation three years ago, wireless customers are now girding to do the same thing all over again, and purchase systems that will work the 500-MHz and other ranges.
Wireless manufacturer Sennheiser has publicly petitioned the FCC to create a compensation formula that will mitigate the cost of purchasing new wireless audio systems for professional users once another round of spectral reallocation occurs. Other manufacturers have voiced support for that. For instance, in a statement filed with the FCC on Nov. 7, wireless microphone maker Audio-Technica stated, “A-T agrees with Sennheiser that the Commission has the authority to require spectrum auction winning bidders to reimburse wireless microphone users who will be displaced from the band as result of the auction and that basic fairness requires such reimbursement.”
A compensation formula could help make a frequency migration somewhat less financially burdensome for the largest buyers of wireless microphones, such as rental houses. But the frequency destinations are also more numerous and diverse, so no one knows what the scenario surrounding the next spectrum auction will look like. As noted, lower ranges require bulkier hardware, but higher frequencies bring their own baggage. The 2.4-GHz range, where some kinds of wireless microphone systems already reside, tends to be noisy and crowded with everything from cordless telephones to Wi-Fi and Bluetooth devices. And higher frequencies require additional power to move signals the same distance. Joe Ciaudelli, director of advanced projects at Sennheiser, says that while it takes 10 milliwatts to transmit a signal one kilometer in the 500-MHz band, to do the same thing in the 2.4-MHz range would require a 1-watt power level -- 10 times more.
Ciaudelli suggests that wireless audio could move into the 1.8-MHz range, where many European wireless operations take place, but that would require regulatory changes by the FCC. “And it still would mean financial hardship for customers who would have to buy new systems anyway,” Ciaudelli points out.
Manufacturers’ concerns about the costs of another round of spectrum depletion to their biggest customers are not misplaced. PRG, one of the largest event-production AV suppliers globally, has approximately 2,000 channels of wireless microphone systems, nearly 400 channels of IEM (in-ear monitor) systems, and roughly 450 channels of wireless intercom operating in the UHF range in its multi-million-dollar North American wireless audio inventory. David A. Strang, PRG’s general manager of audio, says the costs to address another round of equipment acquisitions prompted by spectrum allocation changes will be substantial. Specific concerns aside from the replacement costs include uncertainty about existing equipment acquisitions remaining usable before they are fully depreciated, which should be at least 10 years for a wireless microphone system (according to several manufacturers), making ROI projections difficult.
“I’m very much concerned that equipment that we’ve recently purchased as a result of the transition to DTV and for other reasons is going to need to be replaced before it’s fulfilled its useful life,” says Strang.
However, Strang finds some optimism in the fact that the FCC, under newly appointed chairman Tom Wheeler, who took over the agency in November, is moving cautiously, looking into niche fixes. What also may be slowing the FCC’s auctions is concern over the perceived ability of the Federal government to construct and run a website for the management of reallocated spectrum in the wake of the healthcare.gov fiasco.
All this has left the wireless audio industry sector -- both manufacturers and users -- with uncertainty about the shape of their near-term future. And not knowing exactly when and how spectrum change will take place is for some even more unsettling than the fact that it will take place at all.
“No one wants to make investments into wireless technology until this is resolved, and that impacts everyone, from manufacturers to rental houses like us to our clients,” says PRG’s Strang. “The uncertainty is the worst part.”