Theatrical Sound Designers and Composers Association

by Howard Kaufman

As you may be aware, the FCC is in the process of concluding yet another spectrum auction that will have a profound effect on the operation of wireless microphones across the USA.  After the imminent completion of the auction there will be a gradual changeover of a good portion of the 600MHz frequency band.  This spectrum will be given over to the wireless service industry (cell phones/data).  The transition will proceed for 39 months from the completion of the auction, so the use of the 600 Mhz band is still viable for approximately the next 4 years.

BACKGROUND: The original goal of this auction was the sale of 126MHz of spectrum.  The FCC designed it to allow for multiple rounds, each one offering progressively less spectrum until market demand matched the spectrum offered.

UPDATE: The 600MHz UHF band auction, which began last spring, is finally coming to a long awaited conclusion. The result is that  84MHz of spectrum will be transferred to the wireless carriers and other parties and will result in the loss of TV channels 38-51, (614-698MHz). Since 37 was, and will continue to be, off limits for wireless mics, the remaining usable band will be UHF TV channels 14-36.

The FCC is now faced with the task of reassigning the existing TV stations in the upper 600MHz spectrum to new channels below 608MHz in a process called “repacking”. For the time being we know exactly how much spectrum is going to be lost, but we cannot yet predict what the exact channel lineup in any particular city or town is going to look like.

In a way, this news is heartening.  Much less spectrum is being lost than we had originally feared. The original goal of the auction, had it been successful, would have taken away 126MHz of the UHF spectrum. We are grateful that the final loss of only 84MHz will be much less harmful to the operation of wireless microphones and other wireless gear.

The final Channel Reassignment Public Notice (CRPN) that the FCC will publish in the coming weeks will trigger a 39 month “clock” after which time all wireless microphone operation above 614 MHz must cease, except for a couple of small reserved bands, (totaling only 12MHz).  What remains in the UHF TV spectrum will be 470-608MHz.  Users still have a little over 3 years from today to continue using existing gear that can tune above 608MHz.

Most of the manufacturers of wireless microphones will be offering some sort of re-blocking service for some existing gear, or in some cases trade-in allowances toward the purchase of replacements.  Expect announcements in the coming weeks.

Note: some of the rules governing the use of wireless microphones have changed and there will be a greater distinction between licensed and unlicensed users.  We will offer more details in the next newsletter.

The diagram below shows the resulting TV band spectrum.

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