FCC Allows Unlicensed "Level Probing Radar" in Open Air

The Rules Now Require Measuring Emissions in the Main Beam of the LPR Antenna

By Jim Montague

In a long-awaited and helpful regulatory update, the U.S. Federal Communications Commission (FCC) reported Jan. 15 that it's adopted rules allowing "level probing radars" (LPRs) to operate anywhere in the country without a license.

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The Measurement, Control & Automation (MCAA) reports it worked closely with the FCC throughout the regulatory process, and the FCC's technical office drafted a Notice of Proposed Rulemaking in 2012 to revise its former rules to allow unlicensed LPRs in "any type of tank or open-air installation."

The report and order are located at http://hraunfoss.fcc.gov/edocs_public/attachmatch/FCC-14-2A1.pdf. They will be published shortly in the Federal Register, and will become effective 30 days after that.

Specifically, the order modifies Part 15 of the FCC's rules for LPRs to operate on an unlicensed basis in the 5.925 to 7.250 GHz, 24.05 to 29.00 GHz and 75 to 85 GHz bands, and revises the measurement procedures to provide more accurate and repeatable measurement protocols for these devices. The rules now require measuring emissions in the main beam of the LPR antenna, and adjusting emission limits to account for attenuation that occurs upon reflection of those emissions. The new limits will still protect any nearby receivers from encountering interfering signal levels. The FCC's order also granted MCAA's request to continue an option for certifying LPRs under Section 15.209's more flexible emission limits because some LPRs need wider bandwidths than the new rules allow.

In addition, by changing these technical testing requirements, the new FCC rules partially harmonize U.S. rules for LPRs with the similar European Telecommunications Standards Institute's (ETSI) Technical Standard for LPR devices, which also bases its measurements on main-beam emission limits. MCAA also sought this because it will improve the global competitiveness of U.S. level instrumentation manufacturers.