J. Randy Hoffman

Abstract: This report describes field measurements to characterize Land Mobile Radio (LMR) channel occupancy of Federal bands 162–174 MHz and 406–420 MHz at a single central location in the Washington, D.C., area. This is part of the National Telecommunications and Information Administration effort to evaluate the spectrum efficiency in the Federal frequency bands. Measurements of the received signal levels in LMR frequency bands 162–174 MHz and 406–420 MHz were performed over an eight day period for the purpose of determining channel usage within the measurement system's coverage area of approximately 100–km radius for base stations, 50–km radius for mobile units, and 25–km radius for portable units. The measurements were made using new equipment and techniques that digitize as much as a 5–MHz segment of spectrum and process it to obtain simultaneous signal levels of up to 400 individual LMR channels. These techniques provided faster measurements, but also allowed enhanced postprocessing of the data to remove effects of impulsive noise

Keywords: spectrum efficiency; measurements; land mobile radio (LMR); channel usage; channel occupancy; Federal radio usage

Disclaimer: Certain commercial equipment, components, and software may be identified in this report to specify adequately the technical aspects of the reported results. In no case does such identification imply recommendation or endorsement by the National Telecommunications and Information Administration, nor does it imply that the equipment or software identified is necessarily the best available for the particular application or uses.

For questions or information on this or any other NTIA scientific publication, contact the ITS Publications Office at ITSinfo@ntia.gov or 303-497-3572.

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