To say that the now-murky future of wireless audio for pro applications is somewhat clouded is somewhat of an understatement. With constantly changing Federal Communications Commission rulings, proceedings and a constant barrage of legalese of every type, what seemed clear yesterday is a completely different picture today. And at risk are not just frequency bands for RF microphones, but also those used on wireless rigs for musical instruments, in-ear monitors, production intercoms and now even systems such as Alto Professional’s Stealth series and AirNetix AiRocks Pro, designed to wirelessly transmit console feeds to mains or delay towers.
Many pro users still have bitter memories of the FCC’s reallocation of TV channels 52 to 69 (the so-called “700 MHz band” from 698 to 806 MHz) in 2008, which was made illegal for pro wireless applications after June 12, 2010. After that 2008 auction, rights to use those frequencies were turned over to big buck players in the telecom marked, and ironically, even today most of those sit idle. Yet, unlike analog television stations that were reimbursed for expenses relating to the move to digital TV and even consumers receiving vouchers for converting their analog TVs, once the 700 MHz band was made non-grata for wireless mic applications, the pro audio community was left with zero, nada, zilch and a pile of gear whose use could potentially lead to a lot of legal trouble.
Afterwards, we grieved, moved on and bought new gear, thinking things were finally settled and the future would be rosy. Unfortunately, Congress and the FCC had tasted the easy pickings revenue source from deep-pocket players in the telecom industry and wanted more. Meanwhile, companies such as AT&T, Verizon, Sprint and others were anxious and ready to bid billions of dollars to own their slice of the spectrum pie.
Then, two years ago, the FCC dropped another bombshell on the audio and broadcast industry, this time announcing plans to auction off nearly the entire 600 MHz band — the 608 to 698 MHz spectrum, which includes UHF TV channels 36 through 51. Understandably, pro audio users — particularly those who bought new wireless systems in the “safe” 600 MHz range after being summarily tossed from the 700 (MHz) club — have been justifiably worried, and with good reason.
So, now the 600 MHz landscape will be up for grabs to the highest bidder at an auction that’s less than a year away. But what’s really going on?
Leading manufacturers of pro wireless systems have been very active in working with the FCC to make the commission aware of the needs of our industry — definitely a good thing. And there has been some talk (but just talk) about a possible slice of UHF bandwidth dedicated to wireless mic users, but we’re far from being home free on this one. And with the FCC under extreme pressure from megabuck lawyers, lobbyists and trade groups serving the well-financed telecom industry, anything is possible.
To get a pulse of what’s happening, we spoke to representatives from two wireless audio manufacturers, Mark Brunner, Shure’s senior director of global brand management and Joe Ciaudelli, director of spectrum affairs at Sennheiser. Although employed by competing companies, both have tirelessly worked on the common goal of supporting the wireless interests of all pro audio users, and were kind enough to share their expertise and insights on the near- and long-term future of pro audio wireless.
First Up, The Auction
One question on the minds of a lot of audio pros relates to the auction itself. “The auction is planned for Q1 2016,” says Ciaudelli. “In his address at this year’s NAB show, FCC chairman Tom Wheeler said this will be the last NAB before the auction. The timing of the incentive auction has been pushed back twice. I believe Chairman Wheeler and the FCC will stick to this latest target period.”
The 2016 auction is quite different from the 2008 version and is presented as an incentive auction where full-power and Class-A terrestrial TV broadcasters will be given the opportunity to relinquish or share their spectrum license, on a voluntary basis, in exchange for a portion of the money generated by the auction. It is unknown how many broadcasters will participate.
“This is going to be a more difficult transition than 700 MHz, largely because we won’t know exactly how much spectrum is going to be repurposed until after the auction,” Ciaudelli explains. “The 600 MHz band will be repurposed, but TV stations that currently live in that band will also be consolidated down within the 500 MHz range, which will congest that band. We’re not just losing 600 MHz, but 500 MHz will be more congested.”
After the auction and channel reassignment announcement, a 39-month transitional repacking process will begin on the 600 MHz band and certain portions in the 500 MHz, but here again, the picture is not so cut and dried.
“At Shure, we’ve recently been focusing on a couple things relating to UHF,” adds Brunner. “One is the post-auction transition timing. According to the auction design, the telecoms who bid on the spectrum will able to access it essentially as soon as the funds have been transferred. Then within 90 days or so, they will have the ability to access it and start services in the spectrum they’ve purchased in the auction. But we know that’s not going to happen uniformly across the country, by any means. It’s about building cellular networks and obviously certain markets will have a priority over others.”
But other than the auction date itself, other portions of the transition timetable are not so easily determined, according to Brunner. “So the auction will occur and the spectrum blocks will be ‘purchased,’ but we will have a patchwork quilt of transitions across the country as the telecoms fire up their networks. It’s not going to be like the 700 MHz case where there was one solid date when everybody had to shut off nationwide.”
Ironically, another major (and still unsettled) issue stems from a question of semantics, “What we’re looking for now is a notice of ‘commencement of operations’ by the telecoms,” Brunner says. “But what exactly does that mean, and how much infrastructure needs to be in place for them to say they’re actually utilizing the spectrum and what are the transition timings and notice rules that relate to that timing?”
Ciaudelli is definitely in agreement on this point. “Wireless mics will be able to remain operating during those 39 months — or — until the broadband carriers commence service within a channel. The definition of ‘commencement of service’ and what that means is being debated right now. If a telecom company starts a service and begins billing customers, that is clearly a commencement of service. On the other hand, if they just stick an antenna into the ground and run a couple tests, does that equate to commencement of service? There’s a real question about how ambiguous this definition is, because a radical shortening of that 39-month transition period could really be difficult for wireless microphone users.”
“We’re advocating for the idea that spectrum shouldn’t lie fallow after being won at auction,” adds Brunner, reflecting on Shure’s position on the issue. “If it’s not going to be utilized, then people who have equipment operating within those bands should be able to continue to use it until the point where the networks actually fire up. And this is one place where we and the white space community have found a common ground — they are advocating for the same cause.”
Staying Within 600 MHz?
So far there’s been a lot of discussion about the disappearing 600 MHz frequencies, but some portions may remain. “There are small pockets within the 600 MHz where the FCC plans to allow white space devices and wireless mics to share (see Fig. 1). Guard bands will separate broadband from broadcast and other adjacent services and a duplex gap are will exist between the uplink and downlink of the broadband services,” says Ciaudelli, while adding this caveat. “At first glance these may seem like good blocks to operate wireless microphones, but as these are essentially buffers for the out-of-band emissions from the broadband devices, operating in there may be susceptible to interference.”
“This will sit right in the middle of the 600 MHz band and is being heavily utilized today.” Brunner notes. “There’s some technical dispute regarding the level of interference that mics operating in that duplex gap and lower guard band will cause to mobile handsets.”
This has been a source of serious contention between the wireless audio and mobile devices communities, notably from CITA, The Wireless Association (originally known as the Cellular Telephone Industries Association), a trade group that lobbies for the “other” wireless industry.
“CITA commissioned a technical study from a company called V-COMM, that indicated there was a high likelihood that white space devices and wireless mics would cause interference to handsets,” Brunner relates. “We put considerable energy into examining the technical parameters they used to reach that conclusion. We responded with an ex parte meeting with the FCC and made a presentation that some of the assumptions used in that analysis were flawed and other assumptions were not made on real-world conditions.”
The test results and comments regarding it can be found in FCC Proceeding 14-165 on the FCC’s web site, http://fcc.gov.
“There’s a lot of 600 MHz gear in the field and people don’t know whether they will be able to operate after the auction. And the duplex gap and the guard bands are examples of some of that equipment,” Brunner explains. “We believe the commission got it right when they said the duplex gap and the guard band are useful chunks of spectrum. The duplex gap will be least 11 MHz wide — almost two TV channels — and the lower guard band will be from 7 MHz to 11 MHz wide, which is significant. We clearly want to use that spectrum and that’s a place where people who are operating 600 MHz gear today could potentially continue to use it indefinitely into the future.”
New Horizons, New Spectra
There is cause for optimism in terms of new bands, but the timing remains a challenge, says Ciaudelli.
“The FCC has stated their commitment to accommodate wireless microphone operators by opening access to alternate frequency bands, but manufacturers can’t start a production line until we know all the rules and regulations for operating in these specific bands — and those are not set yet. We have been working with the FCC to finalize these rules on a fast track so there will be clearer visbility prior to the auction taking place. It can take two to five years between product development and delivering finished goods to customers’ hands.”
According to Brunner, “the Commissioner has realized that this next reduction in UHF will have a significant impact and we need to find other chunks of spectrum to offset that. FCC Proceedings 14-166 is the discussion of new bands of spectrum for wireless mics. The FCC has identified some bands being used today for broadcast-only, aviation flight testing and others that are slated for shared general use. The broadcast-only and aviation flight testing are of particular interest to us because they are close in frequency to UHF and have similar propagation characteristics and performance attributes.”
But like other manufacturers, Shure is keeping all its cards on the table. “We also looking into what high-band VHF might offer and have advocated for some revision to the VHF rules to make them more in line with UHF rules. The long and short of it is any and all options for the pro community will be explored, as it will require a mix of spectrum bands to do the level of productions we’re doing today.”
As with the CITA study, countering misinformation is essential. “The mic industry has been criticized as being slow to embrace digital technology, which could afford greater spectral efficiency for packing more mics into a smaller sliver of spectrum,” Ciaudelli explains. “This is nonsense. The audio industry has long been on the forefront of pushing digital technology and every system we’ve introduced in the past year has been digital. There is a myth that digital is inherently more spectrally efficient that analog technology. Digital does allow for data compression or reduction, but at the cost of audio quality, latency or both. Some technologies have been suggested that would allow packing more mic channels into a given space, but if that resulted in 100 ms of delay — like a cell phone, that would be unacceptable for mics.”
Ciaudelli also added that “Sennheiser has made equipment from 30 MHz up to infrared, which is over 300 GHz. We have the ability to create product in any range. But not all ranges are equal due to differences in wave propagation and signal penetration. And wireless mics are not merely a convenience. They are essential tools used in creating some of America’s greatest products. Our news and entertainment content are among the few things we consistently export far more than we import.”
Interestingly, the phenomenon of spectrum grabbing is not limited to stateside dealings with the FCC. “The drive to re-purpose UHF spectra on a global basis is indisputable,” Brunner says. “The telecoms have raised a keen interest in UHF because it works well and as this transition on a global basis continues, it will lead to a more harmonized solution from pro audio in terms of where we can operate. But the Commission realizes that as you fill one hole, you have to open another. You can’t simply leave this community high and dry, because we support a lot of important productions.”
