If you're a production sound mixer or sound recordist you might have heard that the Federal Communications Commission (FCC) has auctioned off part of the UHF TV spectrum to mobile and cable companies. Since April we've seen plenty of headlines from T-Mobile investing the ridiculous sum of 8 billion dollars to purchase the coveted 600 MHz space in order to expand its network. But what does it all mean and how will it change future filmmaking? No Film School has the answers for you. 

What is this auction stuff? 

The FCC recently held what they called the Broadcast Incentive Auction. It was a two-phase auction that ended in March 2017 which impacted the 600 MHz band of the UHF TV spectrum. Soon, filmmakers and companies making wireless equipment will no longer be able to use the 600 MHz spectrum, with a few exceptions. The frequencies affected are 614-698 MHz or 84 MHz of spectrum space. 

What happened during the auction? 

The initial phase or “reverse auction” gave television stations the opportunity to give up their spectrum usage rights. This was followed by a “forward auction” where mobile and cable companies placed bids on the available spectrum. Afterwards, the TV stations that will remain on air will be “repackaged” and assigned to new channels in the UHF TV band below 608 MHz. The FCC has dubbed the re-purposing initiative the “600 MHz Band Plan.” 

600 MHz Band Plan600 MHz Band PlanCredit: FCC


What is the UHF TV band? 

U.S. television airwaves are divided into two bands: UHF (Ultra High Frequency) and VHF (Very High Frequency). The VHF TV band consists of Channels 2-13, occupying frequencies 54-216 MHz while the UHF TV band consists of Channels 14-83 in frequencies 470-890 MHz. 

Why is the 600 MHz UHF TV band important? 

Wireless equipment, especially wireless microphone transmitters and receivers communicate to each other in the white space of the UHF or VHF spectrum. If you're familiar with products from Sennheiser, Zaxcom, Lectrosonics, Azden, Audio-Technica, Wisycom or Audio Ltd, the frequencies that connect wireless devices are part of either spectrum depending on the configuration.  Now that the FCC has sold part of the 600 MHz spectrum, the amount of clean frequencies that are available has been dramatically reduced.  

Starting in October 2018, the manufacturing, sale, lease or shipment of wireless mics that operate in the 600 MHz service band frequencies will be prohibited in the U.S. 

Why did the FCC choose to auction off the 600 MHz band over something else? 

Well, in 2008, the FCC auctioned off the entire 700 MHz UHF TV band to mobile companies and made a ton of money doing it. Some people today might say because of how successful it was the FCC is looking to make more bank. Others will tell you they're attempting to reorganize a cluttered closet. Either way, what makes the 600 MHz UHF TV band highly coveted is simple: the wireless transmission can propagate through walls more efficiently and effectively than frequencies about 900 MHz. So companies like T-Mobile badly want this part of the spectrum so when you're walking through a building your call won't drop. Additionally, UHF devices can be more compact than VHF. 

What are the exceptions? 

The 600 MHz band is made up of the following four parts:

  • Guard Band (614-617 MHz)
  • Downlink Band (617-652 MHz)
  • Duplex Gap (652-663 MHz) 
  • Uplink Band (663-698 MHz)

Right now, a 10 phase transition is taking place that ends July 13, 2020. When it is complete, wireless devices will be limited to the Guard Band (614-617 MHz) and Duplex Gap (652-663 MHz).

Are there any restrictions operating in the Guard Band and Duplex Gap?

Yes, the FCC has placed the following buffer, power limitations and license restrictions that you will need to know about. 

Guard Band
614-616 MHz: 2 MHz (unlicensed operators)
616-617 MHz: 1 MHz buffer (unavailable for use)

Duplex Gap
652-653 MHz: 1 MHz buffer (unavailable for use)
653-657 MHz: 4 MHz (exclusive to licensed operators)
657-663 MHz: 6 MHz (unlicensed and White Space Devices (WSD)

Power will be limited to 20mW for wireless devices and 40mW for White Space Devices (WSD).

The Sound of InterstellarSound recording from Interstellar

What is a licensed and unlicensed operator?

A licensed operator is classified as Part 74 licensee and includes broadcasters, motion picture producers, cable stations and content creators. The FCC has expanded Part 74 licenses to include professional sound companies and owner/operators of large venues that routinely use 50 or more wireless microphones or similar devices. Meaning, those who "routinely" (not every time) use 50 or more wireless microphones can be eligible for a Part 74 license.

While it does cost money (~$165), becoming a Part 74 licensee has the added benefit of interference protection. Meaning, if you're in the field and an unlicensed user is using the space you registered you have priority. This applies to the entire spectrum, not just the 600 MHz band. 

Most of us fall under the unlicensed user category. 

When does this take effect?

The transition period officially ends July 13, 2020. However, you can run into radio frequency (RF) interference prior to the deadline. The new owners of the 600 MHz band have already started changing the airwaves. 

How can you check the usable space in your production area?

There are several FCC approved administrators you can search. Two we suggest are Key Bridge Global and Spectrum Bridge.  

Can you still buy equipment in the 600 MHz band?

Starting October 13, 2018, the manufacturing, sale, lease or shipment of wireless microphones or similar devices that operate in the 600 MHz service band frequencies (617-652 MHz and 663-698 MHz) will be prohibited in the U.S. 

What will happen to my current audio equipment?

You will first need to check and see if it operates in the 600 MHz spectrum. If it doesn't—high-fives—you're good to go. If it does, companies like Sennheiser are currently offering a trade-in promotion until December 31, 2017. Same with Audio-Technica and theirs goes until March 31, 2019. Others, like Lectrosonics, have a similar program and Zaxcom offers a re-tuning service that changes 600 MHz devices to a friendlier spectrum band. 

What about wireless video equipment? 

While you will be safe with majority of wireless video gear out there, you should double-check to see what type of wireless network it works on. For example, ARRI's WVS system operates in the 5.8 GHz so you're in the clear. You're also safe with gear from Teredek. It's just something to keep in mind when checking specs. 

What equipment can you buy with confidence to work in the U.S.? 

Currently, any UHF TV band system that doesn’t tune above UHF TV Channel 36 (608 MHz) is your best option. VHF options are also available from companies like Azden, but again, with VHF, your range is limited. This is not to say VHF isn't worth considering, it just depends on your needs. 

Wrap Up

Though the FCC has provided some usable portions of the 600 MHz band, we'd advise against buying any 600 MHz gear. Unlicensed users will be limited to 8 MHz of space and 20mW of power starting July 13, 2020. 

Also keep in mind when renting gear after October 13, 2018 that you won't be in violation of the new FCC rules. It's up to rental houses and users to update their own equipment, and if they don't, you can run into radio frequency (RF) issues and possibly fines. 

Key dates: 

  • October 13, 2018 - you can no longer buy, rent or sell equipment that function in 600 MHz service bands
  • July 13, 2020 - transition period is over and new operating rules apply