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New Reports Explore LTE-Radar Interference in 3.5 GHz Band
New Reports Explore LTE-Radar Interference in 3.5 GHz Band
July 2014
To support the Administration's commitment to making available
an additional 500 MHz of spectrum for commercial use by 2020, ITS
continues to perform and publish technical studies in bands
proposed for sharing. In collaboration with a wireless technology
provider, earlier this year engineers from ITS and NTIA's Office of Spectrum
Management (OSM) jointly performed ground-breaking
interference-effects testing between radar signals and broadband
digital communication receivers in the 3550-3650 MHz (3.5 GHz)
band. In July, ITS released two reports that describe these
measurements and analyses.
NTIA Technical Report
TR-14-506, co-authored by Geoffrey A. Sanders, John E. Carroll,
and Frank H. Sanders of ITS with Robert L. Sole of OSM, presents
the results of measurements and analyses of the effects of radar
interference on prototype LTE equipment that might in future
operate in that band. NTIA
Technical Report TR-14-507, co-authored by Frank H. Sanders,
John E. Carroll, Geoffrey A. Sanders, and Robert J. Achatz of ITS;
Robert L. Sole of OSM; and Lawrence S. Cohen of the U.S. Naval
Research Laboratory, presents the results of measurements and
analyses of the effects of LTE interference on a type of radar
receiver that might eventually share spectrum with such
systems.
Using these data, spectrum managers can refine and update the
electromagnetic compatibility (EMC) analyses originally presented
in
NTIA's "Fast Track Report" for possible future spectrum sharing
between LTE and radars in the 3.5 GHz band. The reports do not
identify interference protection criteria (IPC) for either the
tested radar type or the tested LTE networks. But the measurement
results may be used to guide the development of band-sharing EMC
criteria. These data will be critically important to
government and private-sector engineers and spectrum regulators as
spectrum sharing opportunities in the band are explored. They will
need to determine the conditions under which future LTE-type
broadband systems may be able to share 3.5 GHz spectrum with
high-power, incumbent government radar systems.
NTIA welcomes technical readers to review these data and share
questions or comments with the authors.