This blog is really about wireless spectrum, not wireless gear itself, but alliteration is so much catchier in headlines and titles, isn’t it? It’s been a while since I’ve written about wireless spectrum, and in the time since I last wrote about what was happening with the spectrum, the world of wireless has evolved quite a bit. A few years ago, when we talked about wireless in production, we were generally speaking about wireless microphone systems and the FCC’s over-reaching, frustrating and continual selling off of the space in the UHF bandwidth.
To bring you up to speed if you aren’t a location sound mixer or very audio-centric, in June 2010, the FCC instituted regulations that made it illegal to operate wireless microphones within the 700 MHz frequency range in the United States.
With the transition to digital television, TV broadcasters vacated a large section of the UHF spectrum (from 698 to 806 MHz) so the FCC auctioned the 700 MHz band to the highest bidders (including AT&T and Qualcomm) to facilitate the development of wireless broadband internet service throughout the United States. There were a LOT of expensive UHF wireless microphone systems that were basically made worthless in the United States by this FCC move.
So a decade ago, we lost the entire 700 Mhz band for wireless microphones. What’s been happening with our wireless spectrum since then? This quote from the FCC website helpfully explains, “Wireless microphones that operate in the 600 MHz service band (the 617-652 MHz and 663-698 MHz frequencies) will be required to cease operation no later than July 13, 2020, and may be required to cease operation sooner if they could cause interference to new wireless licensees that commence operations on their licensed spectrum in the 600 MHz service band.” Basically, we’ve lost another sizeable chunk of the UHF spectrum, this time to T-Mobile.
It seems sort of unfair that the government can just arbitrarily pull the rug out from underneath our feet a second time, only a decade later, but that’s what has happened. Many of us always thought of wireless spectrum as something owned by the populace our country/society, you know, “By the people, for the people,” and regulated through governmental oversight and enforcement of FCC rules. What many of us now realize is that the FCC essentially has decided, on their own and through a series of weakly publicized hearings and memos, that they can basically auction off any spectrum they’d like to the highest bidder. While many people use wireless spectrum, the amount of Americans who actually need to must be numerically low because, throughout both of these incidents, there has been very little public protest or outcry from citizens or politicians.
What Does This Mean?
Besides wireless microphone users—most typically location sound mixers, live venue sound mixers and video users who utilize wireless microphones in their work—what other factors have come into relevance since 2010? Think about it, the answer’s right on the tip of your tongue, the camera department. Which accessories used to be fairly rare and not used by most low- to mid-range users? How about wireless focus, iris and zoom control systems? What about wireless video monitoring? If you’ve been paying attention or buying camera accessories over the past few years, wireless follow focus, iris and zoom controls (often referred to as FIZ) have become de rigueur in the camera department. As cameras have become smaller, lighter and easier to move thanks to the incredible popularity of gimbals, Steadicam-like devices and sliders, wireless monitoring has also made leaps and bounds from once an extremely expensive, not that high performance tool for high-end production to a relatively low cost, much higher performance tool that’s accessible to almost everyone.
Wireless Video Monitoring
Teradek Systems recently introduced the Bolt 4K, a wireless video monitoring system capable of transporting a 4K video and audio signal from camera to monitor wirelessly at distances up to 5,000 feet with less than 1ms delay. The Bolt 4K is at the high end of the cost/performance spectrum and retails for around $10,000 for the top-of-the-line system. Contrast that with devices like the Accsoon Cineeye, a small 5G wireless video transmitter. The Cineeye can only send up to 1080 60p signal about 300 feet. No audio and the signal is 5G, so viewable on smartphones and tablets, not video monitors but the real kicker is the Cineeye retails for a mere $249.00. When you have a market with products that are effective with a price range of $249.00 to $10,000.00, I think it’s fair to say that wireless video (and audio) monitoring is fully in the mainstream.
Which Spectrum Are These Wireless Non-Microphone Systems Utilizing?
In order to understand which spectrum these new reasonable cost wireless devices are using and what it means to wireless microphone users, some context may help. Most wireless FIZ units seem to be operating in the 2.4Ghz spectrum. Does 2.4Ghz sound familiar to you? It should because 2.4Ghz is where wireless Internet lives. The wireless Internet router you have in your home is beaming its Internet goodness out all over your home at 2.4Ghz. How does a wireless FIZ unit using the same spectrum as wireless Internet work? Turns out surprisingly well. Most people on set tend to have a smartphone sitting in their pockets so you’d think that wireless FIZ units would suffer all kinds of interference and clashing with all of the wireless Internet routers and devices that often surround them.
Then Along Came 2.4Ghz Wireless Microphone Systems
Some audio companies saw the writing on the wall a few years and were able to come up with a new type of wireless microphone system utilizing the 2.4Ghz spectrum. It seems counterintuitive to think that a wireless microphone system that utilizes some of the most crowded, commonly used spectrum available could work, but the 2.4Ghz microphone systems seem to work pretty well in the real world. Part of the key is these systems utilize a 2.4GHz digital transmission with 128-bit encryption, the system is able to constantly monitor and hop between frequencies to maintain the strongest possible signal level at a range of up to around 100 yards. I purchased the Røde Video Wireless system a couple of years ago and it has worked surprisingly well, even on a crowded trade show floor in San Francisco for a computing convention. The 2.4Ghz systems lack the range and signal strength of professional UHF wireless systems (up to 250Mw for a UHF transmitter is allowed in the United States), but for a lower cost prosumer type product, they can be surprisingly effective, often at locations where UHF systems that cost much more aren’t usable because there is too much interference in a particular area.
If you think about it, in the United States, for UHF wireless microphone systems, up to 2010, we used to have the 700MHz spectrum, but the FCC sold that off, and today we have the 600MHz spectrum, but will be losing that in July 2020 thanks to the FCC. In the UHF spectrum, that means there is very little spectrum left. Most of not all of the former 700MHz spectrum and soon, the 600Mhz spectrum users have now all been crowded into the remaining A1 (470 – 537MHz) and B1 (537 – 607MHz) spectrum. The result is, in many areas of the country, it can be nearly impossible to find a clean, unused portion of the wireless spectrum for wireless audio microphone systems. Hundreds of thousands of users have now been crammed into a space that is less than half the size of the spectrum was in 2009. UHF, when there’s usable spectrum, is still your best bet to record a clean, strong, noise-free audio signal wirelessly. But if you have a single or multiple UHF systems, you bring them to a given shoot location and do the frequency scan and there is nothing open that is available to you, what do you do?
My Multi-Tiered Strategy
Thankfully the wireless audio manufacturers like Lectrosonics, Wisycom, Audio LTD., Sennheiser and others haven’t been asleep at the wheel since 2010. They’ve known these huge changes have been coming to the industry to for our use for location sound recording, there have been some interesting and intriguing innovations that provide some alternative to the shrinking UHF spectrum. I’ve been using a three-tiered approach that looks like this:
I prefer to try to use UHF wireless as a primary technology on set.
For when UHF wireless spectrum simply isn’t available or reliable, I carry three of the 2.4GHz systems as alternatives that will sometimes function perfectly when UHF won’t.
As a third tier, my sound kit contains three small, wireless lavaliere sized Tascam DL-10R recorders.
2.4GHz/1.9GHz Wireless Microphone Systems
- Røde, Deity and Sennheiser, as well as others coming to market, are all making wireless audio systems that operate in this spectrum.
- Shorter effective range compared to UHF.
- Wireless microphone systems in this range tend to be lower cost, and possibly not be as ruggedly constructed as the top of the line UHF offerings from Lectrosonics, Wisycom, Audio LTD. and others.
- Fewer channels – 2.4GHz doesn’t have the spread or amount of channel solutions that UHF systems have.
- 2.4GHz needs no license, registration needed worldwide in almost all territories.
Zaxcom holds the U.S. Patent on a wireless microphone system that can record to a separate internal SD card while it’s transmitting to the receiver.
Other manufacturers (Lectrosonics, Tascam, Deity, just to name a few) are introducing various models wireless microphone systems that can record internally but because of the patent in the U.S. that Zaxcom has, none of these units can record and transmit simultaneously, in the U.S.
It’s reassuring to see that even though the FCC is kind of acting irresponsibly in selling off UHF spectrum without involving the majority of population that needs to use wireless spectrum, there are alternatives to keep on recording location sound effectively. Stay tuned for more new audio innovation throughout 2020.