The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.
The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.
NOTE: These reports are available either on-line in PDF (portable document) format or only as hard-copy. If you would like a copy of a report that is not available electronically, please make note of the document number and submit your request to:
NTIA Office of Spectrum Management
System Engineering and Analysis Division
Tel. (202) 482-2608
Fax (202) 482-4595
e-mail edrocella@ntia.gov
As directed by Congress in Section 6401(a)(3) of the Middle Class Tax Relief and Job Creation Act of 2012 (Tax Relief Act), NTIA submitted a report to the President identifying 15 megahertz of spectrum between 1675 MHz and 1710 MHz for reallocation from federal use to non-federal use.
Through this report, the National Telecommunications and Information Administration (NTIA) presents the results of its initial study on the potential use of up to 195 megahertz of spectrum in the 5 gigahertz (GHz) band by Unlicensed-National Information Infrastructure (U-NII) devices. Pursuant to Section 6406(b)(1) of the Middle Class Tax Relief and Job Creation Act of 2012 (Tax Relief Act), NTIA, in consultation with the Department of Defense and other impacted agencies, assessed known and proposed spectrum-sharing technologies. This study also evaluated the risk to federal users if the Federal Communications Commission (FCC) allows U-NII devices to operate in the 5350-5470 MHz and 5850-5925 MHz bands.
The Office of Telecommunications (OT) undertook a detailed program to measure and analyze spectrum utilization in the 2.7. to 2.9 GHz band in the Los Angeles and San Francisco areas in support of an Office of Telecommunications Policy (OTP) Spectrum Resource Assessment task. The measurement program consisted of on-site visits to compare predicted and actual PPI interference patterns, and utilization of the Radio Spectrum Measurement System (RSMS) van to validate the component models used in predicting radar-to-radar interference.
From the measured data and a supporting literature search, it was concluded that ducting and man-made clutter (building attenuation) should be included in the propagation loss predictions in order to improve the prediction accuracy of radar-to-radar interference and radar frequency assignments. Even though potential multipath wave interference conditions can be identified, to account for this analytically would require and extremely complex antenna and terrain model. Due to modeling inaccuracies, the difference between the predicted and actual radar-to-radar Interference-to-noise Ratio (INR) levels may be as large as 22 dB (2σ standard deviation region). However, INR errors of approximately 25 dB can still result in relatively accurate predictions of interference patterns on the victim PPI display for conditions where mainbeam-to-backlobe antenna coupling predominates. In summary, it was concluded that the analytical radar-to-radar interference techniques used in this investigation can be used to predict interference patterns on the victim radar PPI display with sufficient accuracy to allow assessment of radar band congestion, frequency assignment flexibility, and potential of the band to absorb new users.
The FAA is currently developing the Discrete Address Beacon System (DABS) as an evolutionary upgrading of the Air Traffic Control Radar Beacon System (ATCRBS). Questions have been raised regarding the Electromagnetic Compatibility (EMC) of ATCRBS and DABS because of their common channel usage. The committee on Science and Technology, U.S. House of Representatives, requested that the National Telecommunications and Information Administration (NTIA) review DABS as a radio telecommunication system giving particular attention to potential interference problems.
NTIA submits this Progress Report pursuant to the Presidential Memorandum issued on June 28, 2010, which directed the Department of Commerce, working through NTIA and in collaboration with the Federal Communications Commission (FCC), to identify and make available 500 megahertz of spectrum over the next ten years for expanded wireless broadband use.
Abstract: This report describes the methodology and results of an investigation into the source, mechanism, and solutions for radiofrequency (RF) interference to WSR-88D Next-Generation Weather Radars (NEXRADs). It shows that the interference source is nearby base stations transmitters in the Broadband Radio Service (BRS) and the Educational Broadband Service (EBS) and that their out-of-band (OOB) emissions can cause interference on NEXRAD receiver frequencies.
This technical memorandum contains recommendations for antenna models that can be used in performing electromagnetic compatibility (EMC) analysis related to spectrum management. The technical memorandum contains two compilations of antenna parameters. The first one is the collection of rules, regulations, and recommendations regarding antennas that are published by regulators, as well as improving, EMC. NTIA conducted an extensive review and analysis of the existing rules, regulations, and recommendations and compiled the findings in this technical memorandum. The second compilation is the recommendations of antenna parameters for spectrum managers to use in conducting EMC analysis associated with: system review for equipment approval, frequency assignment, and spectrum sharing studies. NTIA evaluated the characteristics of the radio services, the federal usage of the radio spectrum, and the technical merit and practicality of the antenna parameters in the rules, regulations, and recommendations, and then developed recommendations of antenna parameters for conducting these EMC analysis tasks of all of the radio services.
This progress report describes the activities related to the Spectrum Sharing Innovation Test-Bed Pilot Program undertaken during Fiscal Year 2011.