Search Results

The search returned 1,237 publication(s) on its.ntia.gov.

Jeffery A. Wepman, Robert J. Matheson, Kenneth C. Allen, and Robert J. Achatz, “Spectrum Usage Measurements in Potential PCS Frequency Bands,” Technical Report NTIA TR-91-279, September 1991

Spectrum usage measurements were made in several potential Personal Communication Services (PCS) frequency bands in the 600 to 2600 MHz range in five U.S. cities. Geographic dependence (within a city) of spectrum usage was determined for all of the c...

Eric E. Johnson, “HF ALE Simulator,” Contractor Report Unnumbered, August 1991

This manual describes the design and use of a software simulator package for HF radios employing FED-STD-1045/MIL-STD-1988-141A Automatic Link Establishment (ALE). This package employs the simulators for narrow-band HF channels and the standard ALE ...

Presents preliminary results on the objective to subjective quality correlation for a set of 5 test scenes passed through three systems (NTSC, VHS, and DS1 MPEG coding). One objective metric that correlates well with subjective quality quantifies the...

Eric E. Johnson, “HF Simulator: Channel and Modem Modules,” Contractor Report Unnumbered, July 1991

This manual describes the design and use of software simulators for narrow-band HF channels, and for the robust modem specified in FED-STD-1045 and MIL-STD-188-141A. This software was developed by Johnson Research under the sponsorship of the Instit...

George A. Hufford, John R. Godwin, and Vincent S. Lawrence, “Characterization of the HDTV Channel in the San Francisco Area,” Technical Report NTIA TR-91-278, July 1991

If over–the–air High Definition Television (HDTV) is to become a reality it would be useful to know the multipath characteristics of the radio channel over which it will be carried. The Institute for Telecommunication Sciences (ITS) has begun a progr...

Using empirical fits to published data, formulas are suggested for the complex permittivity of ice. The radio frequency may range from 0 to 1000 GHz, and the temperature from 0° to -40° C. It then becomes apparent where additional data would be welco...

Hans J. Liebe, George A. Hufford, and Takeshi Manabe, “A Model for the Complex Permittivity of Water at Frequencies Below 1 THz,” Journal Article, July 1991

Experimental permittivity data of liquid water, compiled from the open literature, were selectively applied to support a modeling strategy. Frequencies up to 1 THz and atmospheric temperatures are covered with an expression made up by two relaxation ...

Leslie A. Berry, F. Kenneth Steele, and William B. Grant, “Frequency Assignment Summary for 1.435 GHz–2.5 GHz Band,” Technical Report NTIA TR-91-274, May 1991

Allocations and assignments for frequencies in the United States between 1435 MHz and 2500 MHz are reviewed and summarized. The summarized data come from the FCC data base and the Government Master File.

John J. Lemmon and Christopher J. Behm, “Wideband HF Noise/Interference Modeling. Part I: First–Order Statistics,” Technical Report NTIA TR-91-277, May 1991

This report discusses the development of a wideband HF noise/interference model. The model is based on measured data and is suitable for implementation in a wideband HF channel simulator. The measured data are described and analyses performed on the ...

This report is an assessment of the telecommunications infrastructure in the Kingdom of Thailand. It stresses the importance of telecommunication development to national growth, identifies impediments to growth, and makes recommendation for their re...

F. Kenneth Steele, William B. Grant, and William E. Frazier, “Measured Characteristics of Selected Non-Licensed Radio Devices,” Technical Memorandum NTIA TM-91-149, April 1991

This report includes NTIA measurements of characteristics of nonlicensed devices. These devices are authorized under the FCC Rules in CFR 47, Part 15. The measured values are intended for use by the Government in analysis of potential interference be...

Rapid development of personal, portable, radio communications is expected during this decade. A primary example of this is the emergence of personal communication networks (PCN). These networks are similar to today's cellular telephone technology. Ho...

Susan L. Rothschild and Joseph E. Farrow, “The RAIDER Program: Radio Algorithms for Integration and Design of Engineering Requirements,” Technical Report NTIA TR-91-276, April 1991

The Radio Algorithms for Integration and Design of Engineering Requirements (RAIDER) program consists of a set of modules which provide an easy to use and precise approach to the complete design and documentation of terrestrial radio links operating ...

Hans J. Liebe, George A. Hufford, and Robert O. DeBolt, “The Atmospheric 60-GHz Oxygen Spectrum: Modeling and Laboratory Measurements,” Technical Report NTIA TR-91-272, March 1991

Molecular oxygen dominates the attenuation and delay rates of dry air throughout the V band (5075 GHz). Both rates display as a function of altitude an intricate pattern which, for the most part, has never been confirmed by experiment. The collectiv...

Martin Nesenbergs and Darren L. Smith, “Mean Synchronization Times for ATM Cells: Derivations and Computational Background,” Technical Report NTIA TR-91-273, March 1991

The mean synchronization (sync) duration time and the mean sync acquisition times are derived and computed for the Asynchronous Transfer Mode of the proposed Broadband ISDN. These waiting times are expressed as functions of channel quality, i.e., the...

Hans J. Liebe, George A. Hufford, and Robert O. DeBolt, “Attenuation and Delay Rates of Dry Air at V-band frequencies (50–75 GHz),” Data, March 1991

NTIA Technical Report TR-91-272, March 1991, describes measurements taken during an experiment to confirm modeled attenuation and delay rates of dry air throughout the V-band (50–75 GHz). Over 4,000 attenuation values are reported for measurements b...

Stephen D. Voran and Stephen Wolf, “Motion-Still Segmentation Algorithm For VTC/VT Objective Quality Assessment,” Technical Contribution, January 1991

The ability of the human eye to resolve detail in a video scene is related to how much motion is present at the point of focus and whether or not the eye can track the motion. Thus, stationary portions of the video scene can be resolved in great deta...

Institute for Telecommunication Sciences, “FY 1990 Technical Progress Report,” Technical Progress Report, January 1991

The Institute for Telecommunication Sciences (ITS) is the research and engineering laboratory of the National Telecommunications and Information Administration (NTIA) of the U.S. Department of Commerce (DOC). ITS provides technical support to NTIA in...

Robert F. Linfield, “Telecommunications Networks: Services, Architectures, and Implementations,” Technical Report NTIA TR-90-270, December 1990

Telecommunications networks are shown to exhibit three attributes that distinguish them from each other, namely, the service offered, the functional architecture necessary to provide this service, and the hardware and software that implements this ar...

George A. Hufford et al., “Characterization of the HDTV Channel in the Denver Area,” Technical Report NTIA TR-90-271, December 1990

Development and testing of various implementations of High Definition Television (HDTV) require knowledge of the multipath characteristics of the radio channel over which the proposed signal will be carried. The Institute for Telecommunication Scienc...