Publications
Use the filters below to narrow publications by offices, programs or categories
Seventeenth Quarterly Status Report to Congress Regarding BTOP
Pursuant to Section 6001(d)(4) of the American Recovery and Reinvestment Act of 2009 (ARRA or Recovery Act) (Public Law No. 111-5), NTIA provides this Quarterly Report on the status of the Broadband Technology Opportunities Program. This Report focuses on the Program’s activities from January 1 to March 31, 2013.
Exploring the Digital Nation: America’s Emerging Online Experience
This report, based on data from the Census Bureau’s July 2011 Current Population Survey (“CPS”) Computer and Internet Use Supplement, updates and substantially expands on the previous study in this series, Exploring the Digital Nation: Computer and Internet Use at Home, issued in 2011. For the first time in eight years, this study goes beyond new findings on computer and Internet adoption in the United States to also present data on Americans’ online activities – what Americans do once they connect to the Internet.
Broadband Availability Beyond the Rural/Urban Divide
While it is commonly understood that broadband is less available in rural communities and more available in urban communities, a simple two-way, rural-urban comparison masks the fact that there is considerable variation in availability within these two types of communities. By assigning communities to one of five categories, it becomes clear that there is not a simple rural/urban divide. Rather, one group of rural Americans has even less broadband access than previously understood and two groups of urban Americans have more broadband than is typically identified.
Tabulations of Propagation Data over Irregular Terrrain in the 230-TO 9200-MHz Frequency Range Part IV: Receiver Site in Grove of Trees
This is the fourth part of a four-part report containing tabulations and graphs of transmission loss data resulting from propagation experiments in the 230 - to 9200-
MHz frequency range conducted over irregular terrain in Colorado. This part presents data obtained at a Common receiver site, located in a small grove of cottonwood
(Populus deltoides) trees, over propagation paths varying in length fro 0.5 to 50 km.
Key Words: UHF propagation data, irregular terrain, UHF
propagation through trees
A Wave Hop Propagation Program for an Anisotropic Ionosphere
This report documents a digital computer program for computing the propagation of LF and VLF radio waves using the wave hop theory. It supersedes NBS Report 8889. The documentation includes a description of the physical model, detailed mathematical formulas, a main function flow chart, a listing of the FORTRAN source deck, and the input and output of a sample case.
Measured and Predicted Long-Term Distributions of Tropospheric Transmission Loss
This report summarizes measurements of tropospheric transmission loss and its long-term variability for nearly 800 paths in various parts of the world. The measurements were made at frequencies from 40 MHz to 10 GHz over distances which range from 10 to 1000 km. Terrain profiles and cumulative distributions of both observed and predicted losses are plotted for more than 500 of these paths. A preliminary analysis of differences between observed and predicted values is included.
Key Words: Cumulative distributions, location variability, long-term variability, measurements, predictions, tropospheric propagation.
A Survey of Microwave Fading Mechanisms Remedies and Applications
After a brief description of the significance of the radio refractive index and its variation in the lower troposphere, a catalog of fading mechanisms is presented. Attention is directed to the supporting refractive index structure, the characteristics of the fading signal, and the available remedies. The phenomena of multipath fading are described, and the theoretical amplitude distributions are presented. Diversity reception (frequency or space) is outlined for reducing the fading due to multipath. Specific expressions are given for determining the frequency or space separations. Successful remedies for microwave fading that are keyed to specific fading mechanisms also constitute a means of measuring the characteristics of the prevailing meteorological conditions. Specific expressions are given to accomplish this for the multipath and diffraction fading mechanisms.
Tabulations of Propagation Data Over Irregular Terrain in the 230-to 9200-MHz Frequency Range Part II: Fritz Peak Receiver Site
This is the second part of a four-part report containing tabulations and graphs of transmission loss data resulting from propagation experiments in the 230 to 9200 MHz frequency range conducted over irregular terrain in Colorado. This part describes data obtained at a single common receiver site at Fritz Peak, Colorado, over propagation paths varying in length from 3.0 to 120 km.
Tabulations of Propagation Data Over Irregular Terrain in the 230 to 9200 MHz Frequency Range Part III: North Table Mountain-Golden
This is the third part of a four-part report containing tabulations and graphs of transmission loss data resulting from propagation experiments in the 230- to 9200- MHz frequency range conducted over irregular terrain in Colorado. This part describes data obtained at a common receiver site, which is located on a high mesa near Golden, Colorado, over propagation paths varying in length from 0.5 to 80 km.
UHF Radio Propagation Data for Low Antenna Heights: Volume I
This report is a presentation in two volumes of measurement techniques, data, comparisons, and conclusions obtained from a UHF propagation measurement program at 230 and 415.9 MHz. Antenna heights were 3 m or less above ground. Vertical polarization was used, and the antennas were omnidirectional in the horizontal plane. The terrain was generally rocky, hilly, and relatively free of trees. Path lengths varied from 2 to 45 km. Volume 1 describes the equipment, techniques, and results and presents data from the Wyoming area, including some buried antenna tests. Volume II presents data obtained in Idaho and Washington.