Radio Frequency Coordination For Events AES PNW Section, Seattle WA April 2016
James Stoffo
UHF Spectrum
6 | UHF TV band MHz Distant / low field strength TV signal: co-channel operation possible Full power TV Exclusive mic channels Ch 14Ch 37Ch 51 Shared white space channel Downl ink Uplin k Guard band: unlicensed operation of unlicensed TVWS & mics Duplex Gap for licensed mic use. High noise floor possible Duplex Gap for unlicensed TVWS Naturally occurring White Space channel. Higher activity as more TVWS devices enter the market Possible strategies in the UHF band as we know it… Now Future?
We won’t know until the auction is over and FCC issues complete results. ► ■ 3 year transition period. Keep searching for news stories: “FCC auction wireless microphones white space” etc.
Part 74 Licensing The Part 74 License will allow Licensed operation of wireless mics, wireless in ear monitors, and wireless communications in the following bands. Frequenices Transmission Power 54MHz - 72MHz50 mW 76MHz - 88MHz50 mW 174MHz - 216MHz50 mW 470MHZ - 698MHz250mW Users who routinely work with 50 or more frequencies are eligible to apply for and be protected under the FCC’s Low Power Broadcast Auxiliary (LPBA) Part 74 License providing immediate access to the white space database and offering the right to reserve necessary frequencies for a production or event.
Geo-location Database Database shows which TV channels are reserved for wireless mics and comms Registering event protects you from interference on non-reserved channels Licensed users get immediate access Unlicensed users need FCC approval first 30-day advance notice required Expect them to be very selective
Geo-location Databases Currently active databases: Professional Wireless Systems License Assistance
Spectrumbridge results for reserved mic channels in 98109
Intermodulation Analysis System
RF Explorer
Clear Waves Software
Frequency Coordination
Intermodulation Distortion (IMD)
Metal Trays Reduce IMD
RF Level Comparison, InTrays and Out
IAS Demo
IAS Frequency Coordination Report
Get Creative Test Your Assumptions Keep Records, Track Changes Watch This Space