Spectrum is a limited resource upon which the world makes continually increasing demands. It is therefore natural and compelling to study the efficiency with which radio systems use spectrum. Spectrum efficiency studies reveal how future systems can ...

Frame erasures and background noise are two factors that can interact with speech coding to reduce speech intelligibility and thus impair public safety mission-critical voice communications. We conducted two tests of intelligibility in the face of th...

Version three of Advanced Wireless Services (AWS 3) radio systems will soon use spectrum that is adjacent to bands currently used by airborne telemetry links at U.S. government test and training ranges (TTRs). Spectrum sharing analyses need to be per...

Future spectrum sharing between high-power radars and Citizens Broadband Radio Service Device CBSD in the 3550–3650 MHz (3.5 GHz) band could expose radio frequency (RF) receiver front-end low noise amplifiers (LNAs) to high peak power radar pulse sig...

We describe the design, implementation, and analysis of a speech intelligibility test. The test included five codec modes, four frame-erasure rates, and two background noise environments, for a total of 40 conditions. The test protocol required twent...

A spectrum sharing scheme is considered in which ship-based radar stations are operating in the same spectrum band as on-shore communication transmitters, and in which the communication transmitters will cause interference to the radar receivers when...

We describe a major effort to quantify the speech intelligibility associated with a range of narrowband, wideband, and fullband digital audio coding algorithms in various acoustic noise environments. The work emphasizes the relationship between these...

Great emphasis is seen on the networking and data management aspects of spectrum monitoring, but far less attention is given to the radio frequency (RF) sensor systems used to collect the spectrum data. This report focuses on these sensor systems and...

This report describes a comprehensive series of tests that were conducted by engineers and researchers from the U.S. Department of Commerce’s Public Safety Communications Research (PSCR) program and the University of Colorado during the period of Jul...

This report describes the 3.5 GHz Study. It explains the assumptions, methods, analyses, and system characteristics used to generate the revised exclusion zones for small-cell commercial broadband systems to protect federal radar operations (ship and...

This report details a method that was developed to identify all potential forms of interference that could occur with a proposed collocation of three Federal systems in the 1675–1695 MHz frequency band. The incumbents are the National Oceanographic a...

Spectrum reallocations may place broadband radio services (BRS) near spectrum used by 2900–3100 MHz band marine radars. Interference effects from these reallocations include unwanted emissions in the radar detection bandwidth and front-end overload. ...

Spectrum reallocations may place broadband radio services (BRS) near spectrum used by 2900–3100 MHz band marine radars. Signals from the BRS base stations can potentially introduce unwanted emissions in the radar detection bandwidth and cause interfe...

Spectrum reallocations may place broadband radio services (BRS) near spectrum used by 2900–3100 MHz band marine radars. Signals from the BRS base stations can potentially cause the radar front-end to overload and cause interference. This report provi...

In response to proposals to introduce new Long Term Evolution (LTE) radio systems into the 3550–3650 MHz (called 3.5 GHz) portion of radio spectrum in the United States, a joint team of National Telecommunications and Information Administration (NTIA...

This report examines the problem of how to allocate limited network resources in a public safety LTE network for the purpose of disseminating video streams to end users. We develop a mathematical model of the network environment, including the defini...

In response to proposals to introduce new Long Term Evolution (LTE) radio systems into the 3550–3650 MHz (called 3.5 GHz) portion of radio spectrum in the United States, a joint team of National Telecommunications and Information Administration (NTIA...

In response to proposals to introduce new radio systems into 3.5 GHz radio spectrum in the United States, the authors have performed measurements and analysis on effects of interference, from a variety of radar waveforms, to the performance of a prot...

In response to proposals to introduce new Long Term Evolution (LTE) microcell Citizens Broadband Service (CBS) radio systems into 3550–3650 MHz (3.5 GHz) radio spectrum in the United States, the authors have performed measurements and analysis on eff...

NTIA is responsible for managing the Federal Government’s use of the radio spectrum. In discharging this responsibility, NTIA uses the Radio Spectrum Measurement System to collect spectrum occupancy data for radio frequency assessments. This report s...

This report presents spectrum occupancy data of the 3550–3650 megahertz (MHz) maritime radar band measured in June 2012 near San Diego. In this band, the military operates SPN-43 air marshaling radar systems with well-defined signal characteristics. ...

In response to proposals to introduce new radio systems into 3550–3650 MHz radio spectrum in the United States, the authors have performed measurements and analysis on effects of interference from a variety of radar waveforms to the performance of a ...

NTIA is responsible for managing the Federal Government’s use of the radio spectrum. In discharging this responsibility, NTIA uses the Radio Spectrum Measurement Sciences system to collect spectrum occupancy data for radio frequency assessments. This...

NTIA is responsible for managing the Federal Government’s use of the radio spectrum. In discharging this responsibility, NTIA uses the Radio Spectrum Measurement Sciences system to collect spectrum occupancy data for radio frequency assessments. This...

This report describes a modified rhyme test (MRT) conducted to characterize the behavior of digital and analog communication in the presence of background noise and moderate RF channel degradation. This is done through the use of reference systems to...

This report describes a free-field radio frequency (RF) measurement system that is currently being developed by engineers at the Institute for Telecommunication Sciences (NTIA/ITS). The objective is to provide estimates of the electrical properties o...

This report describes speech intelligibility testing conducted on the Adaptive Multi-Rate (AMR) speech coder in several different environments simulating emergency response conditions and especially fireground conditions. The intelligibility testing ...

We provide detailed descriptions of recent measurements conducted by the National Telecommunications and Information Administration Institute for Telecommunication Sciences in Boulder, Colorado. ITS engineers performed a comprehensive series of bot...

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 ...

Measured power levels for radio frequency (RF) pulses that are frequency modulated (chirped) vary as a function of the bandwidth in which the measurement is performed; if chirped pulses cause RF interference, the power levels of the pulses in victim ...

When radiofrequency pulse envelopes are observed away from their fundamental frequency their shapes differ from those at their fundamental frequency. Off-fundamental pulse envelopes tend to exhibit spikes at their rising and falling edges with lower-...

In early 2009, the Federal Aviation Administration (FAA) became aware of interference to Terminal Doppler Weather Radars (TDWRs) that operate in the 5600–5650 MHz band and provide measurements of gust fronts, windshear, microbursts, and other weather...

This report describes one of three free-field radio frequency (RF) measurement systems that are currently being developed by engineers at the Institute for Telecommunication Sciences (NTIA/ITS). The objective is to provide estimates of the electrical...

The total radio frequency (RF) field strength is the sum of all signals incident at a given location. These signals can originate from many directions and have various polarizations. This complicates the measurement of the total RF field since common...

NTIA/ITS has developed an improved electromagnetic compatibility (EMC) analysis method that can be applied to more accurately model real scenarios for evaluating interference. The methodology described in this report can be used to conduct EMC analys...

Reliable public safety communications between system repeaters outside a building and portable radios inside a building is often not possible due to building attenuation. To circumvent this problem, increasing numbers of municipalities are requiring ...

Man-made radio noise measurements were conducted in a 1.16-MHz bandwidth at 112.5, 221.5, and 401 MHz at two residential and two business locations in the Boulder/Denver, Colorado, area. The measurement frequencies and bandwidth were selected using t...

In early 2009, the Federal Aviation Administration (FAA) became aware of interference to Terminal Doppler Weather Radars (TDWRs) that operate in the 5600–5650 MHz band and provide quantitative measurements of gust fronts, windshear, microbursts, and ...

This paper describes radio channel sounding measurements and analysis using pseudo-noise (PN) codes. It presents a channel sounding model and shows how channel measurements can be made. A measurement system is described that can be implemented using ...

In early 2009, the Federal Aviation Administration (FAA) became aware of interference to Terminal Doppler Weather Radars (TDWRs) that operate in the 5600– 5650 MHz band and provide quantitative measurements of gust fronts, windshear, microbursts, and...

Digital signal processing algorithms are commonly used to obtain radio spectrum estimates based on measurements. Such algorithms allow the user to apply a variety of time–domain windows and the discrete Fourier transform to RF signals and noise. The ...

This report describes a recent measurement effort conducted by the Institute for Telecommunication Sciences at a chamber located at the NASA Space Power Facility (SPF) in Sandusky, Ohio. The report describes the chamber and the measurement system, an...

Even under ideal circumstances, insufficient spectrum is available for assigning a unique band of frequencies to each communication system. In less ideal circumstances, when a communication system experiences outages due to equipment failure or natur...

This report describes emission–spectrum measurements of a denial–of–service (jammer) transmitter that was operated temporarily in 800 MHz and 1900 MHz cellular and PCS bands at a prison location. The jammer targeted signals indoors within a minimum–s...

When bit errors are introduced between a speech encoder and a speech decoder, the quality of the received speech is reduced. The specific relationship between speech quality and bit error rate (BER) can be different for each speech coding and channel...

This report describes emission measurements on a denial–of–service (jammer) transmitter operating in the 800 MHz and 1900 MHz cellular and PCS bands. The jammer operates at a power level of up to 100 watts in each band, repetitively sweeping a carrie...

This report presents techniques for evaluating objective video quality models using overlapping subjective data sets. The techniques are demonstrated using data from the Video Quality Experts Group (VQEG) Multi-Media (MM) Phase I experiments. These r...

The study of noise and interference in the radio environment is essential to the development of efficacious communications systems. Many of the characteristics of radio noise and interference of interest to radio system designers can be expressed in ...

The systems used for public safety speech communications must be intelligible. It is also desirable that they transmit secondary information, such as the attributes of a speaker's voice. This secondary information can allow a user to identify the spe...

This report describes field measurements to characterize Land Mobile Radio (LMR) channel occupancy of Federal bands 162–174 megahertz (MHz) and 406–420 MHz at a single location overlooking the Denver, Colorado metropolitan area. This is part of the N...

This technical report describes the results of a study exploring the effects of power-producing wind turbines on Federal Aviation Administration (FAA) air traffic control (ATC) radars. The study was performed to identify the extent to which these eff...

This report describes an experiment conducted to measure the intelligibility of selected radio communication systems when those systems are employed in high-background-noise environments experienced by firefighters. The test plan for a Modified Rhyme...

This report describes four Reduced Reference (RR) video calibration algorithms of low computational complexity. RR methods are useful for performing end-to-end in-service video quality measurements since these methods utilize a low bandwidth network ...

This report evaluates the efficiency of federal spectrum use, performing a study that compares the spectrum resources used by several alternative land mobile radio (LMR) system architectures employing trunked radio technology to the spectrum resource...

On October 14, 2004, the Federal Communications Commission (Commission or FCC) adopted a Report and Order that defined new Part 15 rules for Access Broadband over Power Line (BPL) systems. The National Telecommunications and Information Administratio...

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 Telecommunication...

An investigation of different propagation modeling methods to meet the special requirements of a short-range propagation model with low antenna heights was performed, and has resulted in the development of approaches to be taken to accurately model r...

This report describes how the current frequency assignment process influences spectrum efficiency in the federal land mobile radio frequency bands. In light of the increasing demands for land mobile radio communications, federal spectrum managers mus...

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This report describes four Reduced Reference (RR) video calibration algorithms of low computational complexity. RR methods are useful for performing end-to-end in-service video quality measurements since these methods utilize a low bandwidth network ...

This report provides results from tests that measured digital television (DTV) susceptibility to ultrawideband (UWB) interference. A test system was developed to inject interference with known characteristics into a victim receiver and quantitatively...

This report describes the results of interference tests and measurements that have been performed on radar receivers that have various missions in several spectrum bands. Radar target losses have been measured under controlled conditions in the prese...

Measured antenna patterns of an end-fed slotted waveguide antenna and a phased-array patch antenna used in maritime radionavigation radars across the frequency range 8500-10800 MHz are presented along with a measurement technique that characterizes t...

This report presents the results of the first phase of a two-phase study of interference protection criteria (IPC) to compile, explain and validate, modify or supplement the levels of protection from interference that are generally expected and provi...

This report describes four Reduced Reference (RR) video calibration algorithms of low computational complexity. RR methods are useful for performing end-to-end in-service video quality measurements since these methods utilize a low bandwidth network ...

This report demonstrates that digital television (DTV) susceptibility to gated-noise interference cannot be predicted by interference power characteristics alone. It was found that DTV susceptibility is also dependent on temporal characteristics of t...

The wide application of radar for various functions makes large demands on the electromagnetic spectrum, and requires the application of effective frequency management for the equipment and systems involved. Requirements for certain equipment charact...

In this study, we hypothesize that ultrawideband (UWB) interference potential can be quantified in terms of UWB signal characteristics. To test this hypothesis, a test system was designed and built to inject UWB signals with known characteristics int...

The objectives of this technical study are to define interference risks from operation of BPL systems under field strength limits and associated compliance measurement procedures specified in Part 15 of the Commissions rules, identify interference ri...

In radio frequency (RF) measurements the gain (or loss) of the signal path connecting the measurement equipment to the measurement reference plane must be accounted for. This tutorial paper discusses the various definitions of gain, and how to determ...

Radiowave propagation measurements made in an urban area of Denver, Colorado, are described. Wideband, impulse response measurements were made at 4 carrier frequencies from 420 MHz to 5750 MHz. Basic transmission loss slope and delay spread statistic...

As part of the overall spectrum management process, the National Telecommunications and Information Administration (NTIA) and the Federal Communications Commission (FCC) have developed radio regulations to help ensure that the various radio services ...

This report describes laboratory measurements to determine the extent and nature of interference to Public Safety radio receivers by ultrawideband (UWB) signals. Two Public Safety radio receivers from different manufacturers were tested in the 138-MH...

Wideband channel transfer function measurements were made for a 16-element transmit and 16-element receive, multiple input, multiple output (MIMO) antenna array. The measurements were conducted using the National Institute of Standards and Technology...

The identification of linear systems from input and output observations is an important and well-studied topic. When both the input and output observations are noisy, the resulting problem is sometimes called the "errors in variables" problem. Existi...

Objective metrics for measuring digital video performance are required by Government and industry for specification of system performance requirements, comparison of competing service offerings, service level agreements, network maintenance, and opti...

A bit error model that enables simulations of the digital error performance of wireless communication links has been developed. The model development has been based on error sequences derived from waveform simulations of wireless link performance wit...

Pulsed signals in Earth station receiver spectrum bands have traditionally occurred due to unwanted emissions from adjacent-band transmitters such as radars and altimeters. Analog Earth station receivers sometimes experience interference from such em...

The objective of this report is to assess the vulnerability of telecommunications switching stations and cellular base stations to high power electromagnetic radiation generated by an RF device. Analyses, measurements, and simulations of indoor propa...

Man-made noise generated by automotive ignition, power distribution and transmission, industrial equipment, consumer products, and lighting systems degrades the performance of radio systems. Man-made noise models, derived from measurements made in th...

This addendum to NTIA Report 01-384 describes laboratory measurements on two additional Global Positioning System receivers to quantify the effects of ultrawideband interference on those receivers. The laboratory measurements were performed by insert...

Software defined radios (SDR’s) represent a departure from traditional radio design. There is some mystique about what SDR’s are, how they are designed, how they operate, and how performance is determined or verified. This report provides insight int...

This report describes the objective testing of various vocoders, both singly and in different combinations of tandem configurations, to evaluate overall voice quality in an objective manner. The objective test evaluation was performed using a standar...

A study was performed to determine the increase in ambient electromagnetic field strengths that would result from a proposal to locate a cluster of terrestrial digital television (DTV) transmission towers in proximity to the Department of Commerce (D...

This report describes the electronic, computer-based processes of creating an on-line, Web-based glossary of telecommunication terms—American National Standard, T1.523-2001, Telecom Glossary 2000. These e-mail processes or Web-based processes constit...

This report describes laboratory measurements of Global Positioning System (GPS) receiver vulnerability to ultrawideband (UWB) interference. The laboratory measurements were performed by inserting increased levels of UWB interference until an operati...

Ultrawideband (UWB) technology, useful for both communication and sensing applications, uses the radio spectrum differently than the vast majority of radiocommunication technologies. UWB systems make use of narrow pulses and time-domain signal proces...

High level electromagnetic fields can upset and damage electronics, as well as disrupt or disable computer software. Thus, high power radio frequency (RF) fields pose a threat to critical infrastructures such as telecommunications. This report examin...

Radiowave propagation measurements at Edwards Air Force Base, CA are described. These measurements were made as part of the Flexible Interoperable Transceiver (FIT) Program. The objective of the measurements is to define communication link requiremen...

Radiowave propagation measurements at Ft. Hood, Texas are described. These measurements were made as part of the Flexible Interoperable Transceiver (FIT) Program. The objective of the measurements is to define communication link requirements at 440, ...

In this study we investigated the geometric optics (GO) approximation to the fields of an incremental electric dipole above a half plane for geometries typical of wireless indoor communications. This inspection was motivated by efforts to establish a...

The Coast Guard funded the National Telecommunications and Information Administration (NTIA) to perform electromagnetic compatibility (EMC) tests between an ITU-R M. 825-3 (Characteristics Of a Transponder System Using Digital Selective Calling Techn...

This study is an update to a 1993 ITS staff study entitled "A preliminary look at spectrum requirements for the Fixed Services." That study included a description of the services provided in 30 of the Government and non-Government frequency bands bet...

This report describes measurement, modeling, and simulation methods that are used to analyze the relationship between nonlinear operation of a typical PCS portable transceiver power amplifier and battery current, out-of-band power, and link margin. F...

Dedicated short-range communication (DSRC) systems have been proposed for operation at locations across the United States in the 5850- to 5925-MHz band. To establish electromagnetic compatibility between DSRC and other 5-GHz systems, it is necessary ...

This report investigates how antenna polarization and directivity affect indoor radio channel bandwidth and signal coverage. Indoor impulse response measurements were taken at 5.8 GHz for four canonical propagation conditions: within a room, down a c...

The Coast Guard plans to operate an Automatic Identification System (AIS) Digital Selective Calling (DSC) based transponder system as part of the Ports and Waterways Safety System (PAWSS) in the lower Mississippi River. The AIS uses two duplex channe...

The subjective quality of speech and image information, transmitted over a high frequency radio link impaired with varying levels of interference, has been evaluated using software simulation. The high frequency radio link was also degraded by freque...

As a result of the Federal Communications Commission’s radio spectrum realignment initiative, land mobile radio manufacturers are being encouraged to incorporate narrowband and trunking technologies into their designs in order to efficiently utilize ...

This paper discusses the basic aspects of radio-wave propagation and antenna modeling in the medium frequency (MF) band. This band covers the frequencies of 300 to 3000 kHz. More specifically, we are concerned with the ground wave and the sky wave in...

An advanced antenna test bed for evaluating adaptive antennas and next-generation mobile communication systems is described. The key elements of the data acquisition system are 8 simultaneous channels, broadband impulse channel sounding, high speed a...

The National Telecommunications and Information Administration (NTIA) is responsible for managing the Federal Government's use of the radio spectrum. In discharging this responsibility, NTIA funds the Institute for Telecommunication Sciences (ITS) ra...

New lighting devices that emit radio frequencies are being developed for commercial use. Since such devices may interfere with communication systems that utilize the radio spectrum, it is essential that the emission characteristics be carefully analy...

The maritime mobile frequency band supports maritime communications worldwide. Appendix 18 of the ITU Radio Regulations (RR) defines the channels of the maritime mobile service. These channels support a variety of communication functions including:...

The maritime mobile frequency band supports maritime communications worldwide. Appendix 18 of the ITU Radio Regulations (RR) defines the channels of the maritime mobile service. These channels support a variety ofcommunication functions including: pu...

Federal Standard 1037C, Glossary of Telecommunication Terms, contains more than 5800 entries defining the components of several disciplines in telecommunications technology. Use of this large glossary is enhanced with the search engine designed speci...

The transmission of E-mail over high-frequency (HF) radio channels is experiencing widespread use in the Government and military communities. This ability is made possible through the convergence of Internet and radio communication protocols, primari...

Minimum acceptable speech intelligibility of land mobile radios is influenced by a number of factors. These factors include the method of modulation, transmission bandwidth, channel spacing, received signal strength, and the ability of a radio receiv...

Dedicated short-range communication (DSRC) systems, designed to enhance the efficiency of highway travel, have been proposed for operation in the 5850– to 5925-MHz band. The successful operation of these communication systems depends upon their compa...

Satellite radio system performance in the 136 to 138-MHz VHF meteorological satellite band is compromised by man-made noise external to the receiver. Methods used for predicting man-made noise power in this band are based on measurements conducted in...

Technology field trials for six personal communications services (PCS) common air-interface technologies (whose standards were developed by the Joint Technical Committee on Wireless Access) were performed at the US West Boulder Industry Test Bed (BIT...

The National Telecommunications and Information Administration (NTIA) is responsible for managing the Federal Government's use of the radio spectrum. In discharging this responsibility, NTIA uses the ITS radio spectrum measurement system and portable...

Federal telecommunications standards have traditionally been distributed in hard copy, i.e., in book form, with mandated 5-year revisions requiring a new book or new change pages for every updated edition. Distributing Federal telecommunications stan...

Multipath channels in indoor wireless communication systems exhibit a characteristic power delay profile, which can be a detriment to system performance. In this paper, we present a simplified model for calculating the decay rate of the power delay p...

Many government telecommunications needs, especially those that support National Security and Emergency Preparedness (NS/EP) missions, are becoming increasingly dependent on commercially available equipment and services. This is consistent with the g...

Complex impulse response measurements of a warehouse building were made at 5.8 GHz with a sliding correlator channel probe. These measurements were made with vertically and horizontally polarized directional antennas so performance improvement due to...

Dedicated short-range communication systems have been proposed for operation at locations across the United States in the 5850- to 5925-MHz band. Various search and tracking high-power radars operate at or near this frequency band and are a source...

Field strength measurements of a 300-kHz Differential Global Positioning System signal transmitted at a Ground Wave Emergency Network site at Appleton, Washington were conducted. Data were acquired continually along five different routes and tagged w...

Perceived speech quality is most directly measured by subjective listening tests. These tests are often slow and expensive, and numerous attempts have been made to supplement them with objective estimators of perceived speech quality. These attempts ...

This report presents an analytic model implemented as the computer program of the transfer function of a wideband HF channel model for use in a hardware simulator. The transfer function is the basic input to the hardware simulator. The mathematical b...

Trends within the wireless and mobile communications industry are examined and extrapolated into the near future. The paper examines the relationships between propagation loss and antenna gain at higher frequencies, shows how dense intelligent infras...

A knowledge of the net inductance of the ground plane can aid in the analysis and investigation of printed circuit board emissions. In this report, we present a method, based on the concept of partial inductance, to determine the net inductance of th...

In support of the Federal Railroad Administration of the United States Department of Transportation, the Institute for Telecommunication Sciences (ITS) has completed a field spectrum utilization survey designed to examine individual channel utilizati...

The National Oceanic and Atmospheric Administration, the European Space Agency, and the European Organization for the Exploitation of Meteorological Satellites are designing a weather satellite system that will broadcast digital weather images at VHF...

The maritime mobile frequency band supports maritime communications worldwide. Appendix 18 of the ITU Radio Regulations (RR) defines the channels of the maritime mobile service. These channels support a variety of communication functions including: p...

An interference model applicable to wireless technologies is presented in this report. Specifically, a generic methodology for cellular system self-interference modeling was developed, then applied to two proposed personal communications services (PC...

The Institute for Telecommunication Sciences has developed a computer simulation model that can be used to predict coverage and quality of service for proposed terrestrial communication systems that broadcast digital television such as local multipoi...

Signal strength measurements in the 285- to 325-kHz band were conducted on eight U.S. Coast Guard differential global positioning system beacons along the Gulf and West Coast, and on a Federal Aviation Administration beacon in Bennett, Colorado. Data...

The National Telecommunications and Information Administration (NTIA) is responsible for managing the Federal Government's use of the radio spectrum. In discharging this responsibility, NTIA funds the Institute for Telecommunication Sciences Radio Sp...

This report documents the assessment of FM subcarrier performance for Intelligent Transportation Systems (ITS) applications in three areas of interest in the United States. These areas are: 1) The Interstate 95 corridor from Richmond, Virginia, to Po...

The National Telecommunications and Information Administration (NTIA) is responsible for managing the Federal Government's use of the radio spectrum. In discharging this responsibility, NTIA uses the Radio Spectrum Measurement System to collect data ...

This report examines the additional HF spectrum requirements for the maritime mobile, aeronautical mobile, mobile, amateur, and broadcasting services previously identified by NTIA. This spectrum availability study for the five radio services was prep...

In support of the Federal Highway Administration of the United States Department of Transportation, the Institute for Telecommunication Sciences has completed a laboratory and field test program designed to independently evaluate the performance of a...

A local multipoint distribution system will essentially broadcast television signals (and perhaps more) to subscribers in small cells. It has been proposed to put such systems in the frequency band from 27.5 to 29.5 GHz where the wave length is only ...

This report presents a summary of the available measurement information on the level and statistical characteristics of the background noise environment in the frequency range of 1-3 GHz. The frequency range covers the proposed frequencies for the ne...

This report describes experiments conducted to explore the user-information transfer performance of the broadband integrated services digital network (B-ISDN), the emerging infrastructure for the global information age. These performance experiments ...

Hardware development of analog-to-digital converters (ADC's) and digital signal processors, including specialized integrated circuits, has advanced rapidly within the last few years. These advances have paved the way for development of radio receiver...

A method of high frequency (HF) radio interoperability testing in accordance with Federal Standards 1045A and 1046/1 is now available on a compact disc (CD) created by engineers at the National Telecommunications and Information Administration, Insti...

Building penetration measurements were taken simultaneously at three potential Personal Communications Services (PCS) frequencies: 912, 1920, and 5990 MHz. The continuous wave (CW) measurement system employed a fixed outdoor transmitter and a mobile ...

For short propagation paths, correctly representing reflections of electromagnetic energy from surfaces is critical for accurate signal level predictions. In this paper, the method of homogenization is used to determine the effective material propert...

The results of a series of data communication tests, which define the digital end-to-end performance of the Advanced Communication Technology Satellite (ACTS), are presented. The experiment consisted of a test set characterization to determine the ef...

NTIA is responsible for managing the Federal Government's use of the radio spectrum. In discharging this responsibility, NTIA uses the Radio Spectrum Measurement System to collect data for spectrum utilization assessments. This report details such a ...

This engineering manual describes a user–friendly and menu–driven computer program called the Jammer Effectiveness Model (JEM). The models used in JEM to analyze the effectiveness of a jammer in jamming a receiver/transmitter pair or network of recei...

This report provides the results of radio spectrum measurements performed to characterize the aggregate signal emissions present in the 2400–2500 MHz industrial, scientific, and medical (ISM) band and adjacent frequency bands. These measurements were...

The impulse responses of radio transmission channels over space–earth paths were measured using the coarse/acquisition code signals from the Global Positioning System of satellites. The data acquisition system and signal processing techniques used to...

The six volumes of this report are: Volume 1. Overview; Volume 2. Experiment Design; Volume 3. Data Extraction; Volume 4. Data Reduction; Volume 5. Data Analysis; Volume 6. Data Display This volume is an overview of the American National Standards...

The six volumes of this report are: Volume 1. Overview; Volume 2. Experiment Design; Volume 3. Data Extraction; Volume 4. Data Reduction; Volume 5. Data Analysis; Volume 6. Data Display This volume shows how to design an experiment to evaluate the...

The six volumes of this report are: Volume 1. Overview; Volume 2. Experiment Design; Volume 3. Data Extraction; Volume 4. Data Reduction; Volume 5. Data Analysis; Volume 6. Data Display This volume explains how to conduct a data communication sess...

The six volumes of this report are: Volume 1. Overview; Volume 2. Experiment Design; Volume 3. Data Extraction; Volume 4. Data Reduction; Volume 5. Data Analysis; Volume 6. Data Display This volume shows how the data reduction phase is implemented...

The six volumes of this report are: Volume 1. Overview; Volume 2. Experiment Design; Volume 3. Data Extraction; Volume 4. Data Reduction; Volume 5. Data Analysis; Volume 6. Data Display This volume shows how to analyze a performance parameter from...

The six volumes of this report are: Volume 1. Overview; Volume 2. Experiment Design; Volume 3. Data Extraction; Volume 4. Data Reduction; Volume 5. Data Analysis; Volume 6. Data Display This volume shows how to use software that draws graphs of th...

The ability to rapidly mobilize the telecommunications industry is of concern in National Security and Emergency Preparedness planning scenarios. This report assesses the extent to which the U.S. telecommunications industry is dependent on foreign so...

The Jammer Effectiveness Model (IEM) is a Windows-based computer program which provides an integrated procedure for modeling propagation effects on telecommunication links and the effect of a jammer on communication links and networks. JEM provides t...

A broadband millimeter wave study was completed to characterize the radio channel for Local Multipoint Distribution Systems in Boulder, Colorado. The study determined characteristics for proposed 20-MHz channels centered at 30.3 GHz using two transmi...

"Orthogonal Frequency Division Multiplexing" is an interesting system architecture for high data-rate digital transmission that has been receiving renewed attention. This report is a discussion of how it works and of how it might be used to carry Hig...

This paper provides definitions of spectrum efficiency for general communication systems, then simplifies the definitions so that the spectrum efficiency of several contemporary mobile radio systems can be easily compared. A variety of systems curren...

The railroad industry has proposed an advanced system for train control. This report presents an evaluation of the system development process, with particular emphasis on the data communication system that interconnects dispatch centers, locomotives,...

The susceptibility of 3700– to 4200–MHz fixed–satellite service earth stations to interference from radar signals, and the mechanisms by which such interference can occur, are examined. It is shown that interference can occur even if all currently ap...

Mobile impulse response measurements were taken in the 1850-1990 MHz band in three different macrocellular (cell radii of 5 km) environments: flat rural, hilly rural, and urban high-rise. Spatial diversity with a 15-wavelength separation was employed...

Simulation has been extensively employed to evaluate concepts included in the current generation of standards for automated high–frequency (HF) radio systems. As development proceeds from link–layer technology to network– and higher–layer technology,...

The feasibility of using radio frequencies in the super high frequency (SHF) band (3-30 GHz) for Personal Communications Services (PCS) in buildings depends on the multipath within the structure and the amount of attenuation experienced by the electr...

This report documents the development of a telecommunication strategy for 1994-2003 for the Eastern Region of the U.S. Department of Agriculture Forest Service. The Institute for Telecommunication Sciences (ITS) identified telecommunication needs, as...

The National Communications System (NCS) is responsible for defining operational infrastructures and processes that could be detrimental to the provision of telecommunications equipment and services necessary to the National Security and Emergency Pr...

This report provides results of radio spectrum measurements of 13 individual microwave ovens performed at the National Telecommunications and Information Administration (NTIA) Institute for Telecommunication Sciences (ITS). Measurements include emiss...

This report presents the results of two weeks of bi–directional high frequency radio path soundings in a trans–auroral environment between Christchurch, New Zealand, and the U.S. station, McMurdo (Black Island), Antarctica, during mid–January, 1992. ...

This report provides the results of measurements that were conducted on a 404.37 MHz wind profiler located in Platteville, Colorado. These measurements included: radiated spectra (both high and low mode), radiated harmonic and subharmonic power measu...

This report is an introduction to wavelet theory intended for the technical professional working in telecommunications. The basics of wavelet theory are presented with an emphasis on explanation of the principles and ideas involved rather than on the...

The National Telecommunications and Information Administration (NTIA) in the fall of 1992 was required by Congress to develop and commence implementation of a plan for Federal agencies to use wireless mobile technologies that are spectrum efficient a...

Impulse response measurements were taken simultaneously in both the 902-928 and 1850-1990 MHz bands using a wideband measurement system consisting of a fixed transmitter and a mobile receiver. Four different macrocells representing typical semi-rural...

The present analysis extends the concepts and approaches discussed in [1] and [2] for determining the effective erasure or overwrite of signals on magnetic tapes, as part of a general approach to the development of new, statistical standards for this...

This report presents an analysis and explanation of the system performance calculations performed by the reliability and service probability subroutines of the Ionospheric Communication Analysis and Prediction Program "IONCAP" and an IONCAP derivativ...

The purpose here is to define the present and examine the future of telecommunications over the next ten years. Emerging and anticipated products and services are viewed from both a technical and a social impact perspective. Systems including those p...

The objectives of this report are (1) to identify and examine various divergent perspectives that exist about the technology termed network management; (2) to develop a conceptual definition and understanding of network management that is rational an...

Federal Government spectrum usage in the 902-928, 2400-2500, and 5725-5875 MHz bands

A discrete event simulation model for an HF Automatic Link Establishment (ALE) radio network is described. The simulation model is based on Federal Standard 1045 "Telecommunications: HF Radio Automatic Link Establishment." The simulation is used to s...

Wideband impulse response measurements were made to characterize proposed radio data channels in three indoor environments. The measurement system employed a 1.5 GHz carrier which was biphase shift key (BPSK) modulated using a 100 Mb/s pseudo-random ...

This report is the second in a series of reports which describe the development of a wideband HF noise/interference mode. The model is based on measured data and is suitable for implementation in a wideband HF channel simulator. The measured data, an...

A method of utilizing the Data Encryption Standard (DES) algorithm for linking protection in HF radios complying with Federal Standard 1045 is described. The unique DES encryption method, which permits a codebook type of encryption of 24-bit words, i...

A computer program was developed to calculate the power spectral density (PSD) and the fractional power containment bandwidth for various digital modulation techniques. The power containment capability was used to provide guidance for determination o...

Wideband propagation measurements were made in a pecan orchard in Texas during April and August of 1990 to examine the propagation characteristics of millimeter–wave signals through vegetation. Measurements were made on tree obstructed paths with and...

(Washington) Gerald F. Hurt and Philip E. Gawthrop

This is the third in a series of reports which describe a new and unique approach for modeling either narrowband or wideband high frequency (HF) channels. Although narrowband models of the HF channel have existed for many years, they are applicable t...

Federal spectrum usage of the 1710-1850 and 2200-2290 MHz bands, March 1992

The error variability of received PSK (MSK), QAM and QPR modulations on digital microwave common carrier links resulting from transmitted power variations and the dispersive effects of terrain multipath using a two–ray model is analyzed. These result...

This is a supplementary fifth part to a series of reports containing tabulations and graphs of transmission loss data resulting from propagation experiments which have emphasized the UHF frequency band. The first four reports described data taken in ...

Motivated by recognized vulnerabilities of the terrestrial public networks, this report addresses the question whether an appropriate introduction of advanced satellite systems would or would not benefit the telecommunication services for the current...

Erasure "standards" employing a saturating field which clips a test sinusoidal so that its 3Qharmonic is 12 dB down from the first harmonic is seen to be incomplete. The probability of (just) detecting the erased signal, under false alarm control, is...

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...

This report presents an assessment of three candidate bands (216–225, 400.15–406, and 420–450 MHz) for the potential accommodation of Wind Profilers nationally, with consideration worldwide. The approach used to evaluate each band was based on two ma...

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...

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.

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 ...

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...

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 ...

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...

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...

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...

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...

This report describes the steps for designing experiments to quantify the performance of a communication satellite system according to the methods specified by ANS X3.l4l. Performance is described in terms of performance parameters that are user–orie...

The minimum amount of spectrum to satisfy worldwide broadcasting requirements in the high–frequency (HF) bands is estimated. This analysis provides technical bases for the U.S. allocation proposal$ being developed in preparations for the World Admini...

This report discusses a collection of microwave common carrier azimuthal antenna patterns. The patterns were digitized and stored into a uniformly formatted database. The primary application of this database is for interference prediction among commo...

This report describes an automated method of video quality assessment based on extraction and classification of features from sampled input and output video. The first subsystem of the automated video quality measurement system is the feature extract...

Long–Term Performance and Propagation Measurements on Single and Tandem Digital Microwave Transmission Links Volume I: Analysis of Measurement Data

Long–Term Performance and Propagation Measurements on Single and Tandem Digital Microwave Transmission Links Volume II: Appendixes

Long–Term Performance and Propagation Measurements on Single and Tandem Digital Microwave Transmission Links Volume III: Twelve–Month Network and Link–Characterization Results

This manual describes the functions of the TRAMCON (TRAnsmission Monitor and CONtrol) On#8211;Line software and the steps necessary to maintain the software. This document emphasizes the software semantics rather than the syntax. The structure of the...

In order to determine how effective an erasure procedure is it is necessary to examine the detectability of the remaining signal in tape noise. This detectability can be measured by the probability of correct detection of the signal, which should be ...

A summary is presented of a series of monitoring campaigns held between 1984 and 1989 to locate the sources of intentional harmful interference to the HF broadcast spectrum. The monitoring programs were organized under the auspices of the Internation...

Data from 21 ionospheric sounding stations in the northern and southern hemispheres were used to characterize the day to day variation in the critical frequency of the F2 layer of the ionosphere. Variability in the critical frequencies are analyzed m...

The Institute for Telecommunication Sciences (ITS) has performed a number of technical tasks as part of the responsibilities of the National Telecommunications and Information Administration (NTIA) for re–establishing the Pan-Pacific Educational and ...

International Value–Added Network Services – An Introduction, March 1990

This report presents a detailed assessment of the hydrologic and meteorological operations in the 162–174 MHz (VHF) and 406.1–420 MHz (UHF) bands. These operations are currently supported by hydrologic and quasi-hydrologic channel assignments in thes...

This report examines the potential for ground–based weather radar (meteorological radar) interference to digital microwave systems in the common carrier bands of 3700–4200 MHz and 5925–6425 MHz. Reported cases of interference to microwave common carr...

This report is the second report in a series of reports which describe a new and unique approach for modeling either narrowband or wideband high frequency (HF) channels. Although narrowband models of the HF channel have existed for many years, they a...

This paper discusses the design and the measured performance of a 76.8-kIn (47.7-mi) over–water 2.3 GHz microwave radio link. Since one of the terminals was located on an ocean tower, the maximum antenna height at that location was restricted to 49 m...

This report covers the first task of a three–task effort designed to explore the potential of using advanced satellite system technologies to enhance the rapid restoration of telecommunication services that may be disrupted due to traffic congestion ...

The Second Session of the High Frequency Broadcasting Conference held in Geneva, Switzerland, in February 1987, resolved a need for an improved system to plan the radio frequencies allocated exclusively to the HF broadcasting service. The Final Acts ...

The current status of fiber optic and related broadband terrestrial networks is reviewed. That includes summaries of link and switch capabilities as well as present and future standards for broadband systems. In the domain of communication satellites...

This report is a brief outline and a catalog o full power spectral densities for certain M–ary frequency shift keying waveforms. Spectral equations are displayed in graphical form for easy visualization . The spectra pertain to real signals centered ...

Propagation measurements were made in the Olympic National Forest of Washington state during October 1987 to examine millimeter–wave signal propagation through conifer vegetation. Linearly polarized continuous–wave signals at 9.6. 28.8. 57.6. and 96....

This report presents an overview of moving image (video) data compression. Because this report deals with a subtask of a major program, a limited number of the most pertinent topics and issues have been addressed. These topics include a listing of hu...

The SUM Land Mobile Model: Application of the Spectrum Use Measure to the Land Mobile Service, Sep. 1989 (Washington) R.H. Haines and S.E. Litts

At heights between 30 and 100 km above Earth, the oxygen absorption lines near 60 GHz together with the geomagnetic field cause the atmosphere to become an anisotropic medium. This report discusses why this is so and how to compute the consequent eff...

This report provides a description of and operating instructions for Digital Line–of–Sight (DLOS) programs. These programs, which run on a desk–top computer, automate the calculations involved in design of line–of–sight microwave radio relay paths. T...

This report describes the interim results of an 18–month digital microwave transmission network performance and propagation measurement project that was conducted on a portion of the Defense Communications System (DCS) in West Germany. Only the first...

This report describes an adaptive antenna computer model that simulates the behavior of a steerable–nulling antenna processor (SNAP) in a jamming or interference environment. The model predicts the signal–to– (interference–plus–noise) ratio as a func...

This is the fourth in a series of reports describing the results of studies to determine the location of sources of harmful interference to the high frequency (HF) broadcasting service. Using observations recorded during the July 1988 monitoring prog...

Since the spectrum is a limited natural resource, the spectrum management community has a major interest in identifying spectrum conservation techniques that will provide more efficient spectrum utilization. Advances in new technology for fixed micro...

The technical and operating characteristics of meteor burst systems of importance for spectrum management applications are identified. A technical assessment is included which identifies the most appropriate frequency subbands within the VHF spectrum...

Measurements were performed in an urban–suburban environment with narrowband and wideband rf probes, which include millimeter–wave frequencies, in order to study propagation characteristics for street level paths. The primary objective of this report...

This report describes a new and unique approach for modeling either narrowband or wideband high frequency (HF) channels. Although narrowband models of the HF channel have existed for many years, they are applicable to only a limited set of actual pro...

This report details a study on the application of American National Standards X3.l02 and X3.l4l to various classes of communication satellite systems from the simple analog "bent–pipe" to NASA's Advanced Communications Technology Satellite (ACTS). Th...

The NITA Information Services Report is a study of the information services available via telecommunications networks in the United States and a number of foreign countries. It presents a review of the information services available in the United Sta...

This report describes a new technique for calculating the spectrum space used by existing frequency assignments. The Spectrum Use Measure (SUM) model determines the amount of spectrum used at a given location or the probability that a given location ...

An interactive program has been developed to evaluate the performance of medium frequency (MF) broadcasting systems. The model calculates both ground–wave and sky–wave signals. The user can select from three ground–wave methods: (1) smooth Earth, hom...

This report presents results of a multiyear data communication performance measurement program conducted at the Institute for Telecommunication Sciences, the research and engineering arm of the National Telecommunications and Information Administrati...

Important changes in the video market, particularly with respect to cable television over the last ten years, have raised several policy issues. The expanded technological capabilities of optical fibers and computers create new ways to transport a...

The Mu1itier Specification was developed to provide guidelines and recommendations for improving the durability of the communication installations necessary for National Security/Emergency Preparedness (NSEP). The application of the Multitier Specifi...

This report discusses propagation and performance measurements that were opbtained over a digital troposcatter communication link between Bocksber, West Germany and West Berlin. The measurements were unusual because three gerneral types of data were ...

Minimum (or "best–fit") elliptical beams of satellite antennas have been used for the planning of space services utilizing the geostationary–satellite orbit. In such a planning, beam parameters of minimum elliptical beams are necessary for all possib...

Fiber optic telecommunication systems are susceptible to both natural and man-made stress. national Security/Emergency Preparedness (NSEP) is a function of how durable these systems are in light of projected levels of stress. Emergency Preparedness i...

Fiber optic telecommunication systems are susceptible to both natural and man-made stress. national Security/Emergency Preparedness (NSEP) is a function of how durable these systems are in light of projected levels of stress. Emergency Preparedness i...

In the first section of this report, rainfall observational data are processed by least-squares curve-fitting to call attention to some of the desireable aspects of such fittin. The curve fitting techniques are illustrated for annual rainfall and wor...

The National Communications System (NCS) is responsible for defining reasonable enhancements that could be applied to commercial common carrier (or carriers' –carrier) fiber optic systems that will be leased or owned by government agencies and which ...

Laboratory measurements have been performed at 138 GHz of water vapor attenuation ax for pure vapor (H20) and its mixtures with air, nitrogen (N2), oxygen (O2), and Argon (Ar). Temperatures ranged from 8 to 43°C, relatlve humidities from 0 to 95% and...

Molecular absorption lines in the millimeter-wave band make the atmosphere dispersive, thus causing the distortion of transmitted signal shapes. To better understand how severe this distortion is and what form it takes, it seems useful to examine the...

The U.S. Army Electronic Proving Ground (USAEPG) is planning the development of a new test facility to be known as the Stress Loading Facility (SLF). This facility is envisioned as an integrated and automated test capability that will generate a dens...

In order to determine the feasibility of multiple system decoders for AM stereo receivers, the Institute for Telecommunication Sciences made a series of laboratory and field tests on certain commercially available AM stereo receivers. We also made te...

U.S. Telecommunications Team Report on Nov. 1986 Visit to China: First Implementation Phase of U.S.-China Protocol on Cooperation in the Field of Telecommunications

When wave propagation through a stratified atmosphere is formulated in operator theoretic terms, it becomes evident that the problem does not follow the guide of the usual examples of mathematical physics. Nevertheless, such a formulation is useful t...

A series of programs have been developed by the Institute for Telecommunication Sciences (ITS) that assist the Voice of America (VOA) to plan and operate high frequency (HF) broadcast stations. The VOA has specific broadcast bands available for use a...

Laboratory testing of proposed and new wideband (e. g., spread spectrum) high frequency (HF) systems is currently not possible because wideband HF channel simulators do not exist. Moreover, there are no validated HF channel models for bandwidth on th...

NTIA Regulatory Review Staff

This report describes a fiber optics system model and its computer implementation. This implementation can calculate the bit error ratio (BER) versus time for optical fibers that have been exposed to gamma radiation. The program is designed so that t...

The First Session of the World Administrative Radio Conference for the planning of the high frequency (HF) bands allocated exclusively to the broadcasting service held in Geneva, Switzerland, in January and February of 1984, established the technical...

An expression for the gain of a curtain array antenna over a perfectly conducting, flat Earth with no mutual impedance between elements is derived in this report. A FORTRAN computer subroutine created to calculate the expression is described here. Th...

This is the third in a series of reports describing the results of studies to determine the location of sources of harmful interference to the HF broadcasting service. Using observations recorded during the June 1986 monitoring program conducted unde...

The objective of this study is to look at fiber optics networks in a predominately functional domain and to assess their potential survivability advantages from that point of view. As a consequence, service survivability is emphasized far more than p...

Competition in the Local Exchange Market

American National Standard (ANS) X3.100 will be adopted as Federal Information Processing Standards Publication (FIPS PUB) 100 and Federal Standard (FED STD) 1041. These standards are based on CCITT Recommendation X.25 and ISO Standards 7776 and 8208...

This report presents an updated and improved noise model designed for use in the HF propagation prediction program, IONCAP. The model has, however, much more general applicability, since the frequency range 10 kHz to 30 MHz is covered. The report giv...

An automated analysis model is presented for the prediction of system performance of communication circuits that use the ground wave as the primary mode of propagation. The computer program Ground Wave Automated Performance Analysis (GWAPA) is a user...

A method of interpolation that accurately interpolates data values that satisfy a function is said to have the accuracy of that function. The desired or required properties for a univariate interpolation method are reviewed, and the accuracy of a thi...

Prediction of propagation effects (i.e., path attenuation, phase delay, ray bending and medium noise) over the 1 to 300 GHz frequency range through the clear, nonturbulent atmosphere is accomplished by combining a spectroscopic data base with a compu...

This is the second in a series of reports describing the results of studies to determine the location of sources of harmful interference to the HF broadcasting services. Using observations recorded during the January 1986 monitoring program conducted...

This report describes the mathematical models used in the ARROWS programs. These programs, which run on a desktop computer, automate the calculations involved in the design of line–of–sight microwave radio relay links. The programs calculate, tabulat...

(Washington) Karl B. Nebbia, K. Long, and M. Sussman

An automated analysis model is presented for the prediction of system performance of communications circuits that use the ground wave as the primary mode of propagation. The computer program Ground Wave for Voice of America (GWVOA) is a user–friendly...

This report describes a set of algorithms developed at NTIA for the analytic assessment of interference effects in satellite communication services. These algorithms convert the interference levels at the receiver input into an observable performance...

The analysis technique developed and discussed in two earlier NTIA reports [Farrar, 1984; Farrar, 1983 was used in conjunction with the data obtained from a number of different countries to calculate the power–flux–density (pfd) levels in the 2 GHz b...

The distribution of raindrop sizes in a given volume of air remains an unknown aspect of critical importance to the prediction of rain attenuation at millimeter–wave frequencies. Thus, in this report, the search continues for a methodology of predict...

Fritchman's single–error–state (SES) model for describing the error statistics of digital communication channels is modified to allow the prediction of error statistics as a function of the bit error rate (BER). From the data samples of a measurement...

Measured analog data showing gain as a function of angle away from the mainbeam (maximum gain) axis have been obtained for 14 models of reflector antennas designed for operation at 11/12 GHz for reception and at 14 GHz for transmission. The antennas ...

For efficient use of the geostationary satellite orbit, mutual interference among satellite systems must be analyzed in the planning stage of the systems. To conserve the transmitter power, many satellite antennas in the FSS (fixed–satellite service)...

This report is tutorial in presentation, with emphasis on the application of engineering formulations of the effects of terrain upon terrestrial microwave systems. Many of these formulas have been available for a decade and longer, but they have not ...

Comparisons of the Two–State Markov and Fritchman Models as Applied to Bit Error Statistics in Communication Channels, May 1986

New models of electromagnetic interference (EMI) have been developed by Middleton [1-11 ,48,49] over the last decade (1974-1983), which have provided canonical, analytically tractable, and experimentally well established quantitative descriptions of ...

EHF Telecommunication System Engineering Model, April 1986

An experimental millimeter–wave propagation link was installed on a 1–km path in the northern California area (Gasquet) to compare rain rate and attenuation at 28.8, 57.6, and 96.1 GHz. During the monitoring period (January 26 through April 14), rain...

There has been a significant internationa1 effort to develop standards for Integrated Services Digital Networks (ISDNs) at the same time that events leading to the divestiture of the American Telephone and Telegraph (AT&T) Company were occurring in t...

The millimeter-wave behavior of rain attenuation based on recent experimental data, Jan. 1986

The results of a detailed investigation to isolate the location of sources of intentional interference to the HF broadcasting service are presented. The investigation was conducted using observations of intentional harmful interference observed at nu...

This report discusses quality–of–service (QOS) issues for telephone networks. Deregulation and divestiture have fostered increased competition in the United States in the telephone equipment and service industries. There are many economic, policy, an...

The factors that affect the design of a numbering plan for the Integrated Services Digital Network (ISDN) involved a complex interplay between existing plans, national priorities, and technical system limitations. These factors are the subject of thi...

Measurements reported are part of a study of propagation characteristics for millimeter–wave communication links operating in an urban#8211;suburban environment. Absorption data were collected for signals propagated through some common building mater...

This report addresses the concepts, the justification, and the eventual configuration of military access areas. Many factors enter into this access area characterization effort. The key factors emphasized here are: the current telecommunications envi...

The OSI Network Layer Addressing Scheme, Its Implications, and Considerations for Implementation, Nov. 1985

This report is a study of Travelers' Information Stations (TIS) operating in the 525-535 and 1605-1615 kHz bands. It was prompted by the expansion of the AM broadcasting band from 1605 to 1705 kHz. Included is information on rules and regulations, al...

A Phase I spectrum resource assessment based upon use of the bands containing fixed and mobile services in the 947-17,700 MHz portion of the radio frequency spectrum was completed in 1984. From the total number of fixed and mobile bands, four bands (...

Standards in Process: Foundations and Profiles of ISDN and OSI Studies, Sep. 1985

Several methods for estimating the potential interference from systems in the Fixed Service to Power–Line-Carrier (PLC) circuits were developed. The Numerical Electromagnetic Code (NEC) computer program, originally developed by the Navy, was used to ...

The combined communications probabilities (Cm) have been calculated for 56 Simulated Ship Positions (SSP's) in the North Atlantic to a network of 26 digital selective calling shore stations The Cm are based on individual circuit reliability data obta...

In a cooperative program, the Federal Communications Commission and the Institute for Telecommunication Sciences have begun a study of the interference fields that may arise in a ducting environment. This report gives some preliminary thoughts on how...

The determination of radio communication system performance is a matter of proper statistical treatment of both the desired signal and the real-world noise (or interference) processes. System performance is highly dependent on the detailed statisti...

Local networks, related standards activities of the Institute of Electrical and Electronics Engineers (IEEE) Project 802, the American National Standards Institute (ANSI), and other elements are presented. These elements include 1) technology choices...

This report is a spectrum resource assessment of the 1605–2000 kHz band. It includes information on rules, regulations, allocations, technical standards, frequency assignments, system characteristics, and applicable compatibility analyses pertinent t...

A practical atmospheric millimeter-wave propagation model (MPM) is updated and tested with experimental data from horizontal, line–of–sight links when there is no precipitation. The MPM computer program predicts attenuation and delay properties of mo...

Measured analog data showing gain as a function of angle away from the mainbeam (maximum gain) axis have been obtained for 22 types of reflector antennas designed for operation at 4 GHz for reception and 6 GHz for transmission. The antennas ranged in...

This report shows that for digital modulation systems, the necessary bandwidth, signal power, and bit error rate are all interrelated and tradeoffs among these factors are possible.

In the presence of rain, millimeter–wave propagation is acutely sensitive to the distribution of raindrop sizes along a given propagation link. This report analyzes the variability of rain attenuation prediction at microwave/millimeter wave frequenci...

Telecommunication and computer technologies are merging, stimulating such global communication projects as the Integrated Services Digital Network (ISDN) and the Open Systems Interconnection (OSI) Reference Model. The systems of standards needed to e...

This. report is a spectrum resource assessment of the 7125-8500 MHz band. Included is information on frequency allocations, technical standards, spectrum usage, and identification of spectrum-management issues pertaining to this band. The spectrum-ma...

This report documents a spectrum resource assessment of the 1530-1660.5 MHz band. The impact of allocation changes resulting from the WARC-79 are addressed. Information is included on allocations, frequency assignments, system characteristics, and sp...

The National Telecommunications and Information Administration (NTIA), in keeping with its responsibility for managing the Government's use of the radio frequency spectrum, researches particular bands when changes in national and/or international all...

Calculating the polarization angles of antennas and radio waves is necessary for analyzing the mutual interference when a linearly polarized emission is used in satellite communications. A method for calculating the polarization angle has been develo...

The Institute for Telecommunication Sciences has undertaken an assessment of the link margin required for the satisfactory performance of a direct broadcasting satellite service operating in the high frequency (HF) and in the very high frequency (VHF...

This report is a spectrum resource assessment of the Aeronautical Mobile Service between 400 MHz and 17.7 GHz, which addresses the long-range planning of this service. It presents an assessment of 15 Federal Government frequency bands that are alloca...

This report describes an interactive computer program that facilitates efficient measurement of communication system performance parameters. The program performs three primary functions: (1) determines the minimum sample size required to achieve a de...

An engineering approach to the design of optical fiber communication links to meet mandated specifications for performance and interoperability is described. The report follows and expands upon technical guidance originally developed for MIL-STD-188-...

This report constitutes a Spectrum Resource Assessment (SRA) of the band 17.7-40.5 GHz. Included is information on rules and regulations, allocations, technical standards, current and proposed usage, and planning and coordination procedures. Major is...

This report examines the use of Amplitude Compandored Single Sideband (ACSB) and/or 12.5 kHz FM (NBFM) as possible solutions to the spectrum congestion in the Government Land Mobile Service in the VHF bands. These narrowband modulation techniques are...

NTIA and member agencies of the Interdepartment Radio Advisory Committee (IRAC) have long recognized the need for a set of measurement procedures to augment the Radar Spectrum Engineering Criteria (RSEC). In light of this, a Working Party was formed ...

Measurements of radio propagation path loss were made over four paths in the 3 to 30 MHz band. The paths were of lengths up to 45 km in the Boulder, CO, area. They ranged from smooth to mountainous terrain, from open areas with few or no man-made str...

Assessment of Satellite Power Flux-Density Limits in the 2025-2300 MHz Frequency Range, Part 2

The attenuation of a received signal on a millimeter wave (above 30 GHz) link probably will be considerably more sensitive to transmitted polarization of the signal than is the case on a microwave (below 30 GHz) link. The introduction of this report ...

NETWORK is an interactive computer program designed to help the National Weather Service expand the NOAA Weather Radio Network to obtain the desired coverage at minimum spectrum usage. For each active station, areas of predicted service and co-channe...

This paper describes a minicomputer-based communication system monitor used by the U.S. Department of Defense to improve the performance and reduce the operating costs of the new multi-channel digital transmission systems. A brief history of the deve...

Because rain attenuation continues to be a problem for the operation of microwave links worldwide, this report examines the behavior and the prediction of rain rate and rain attenuation·distributions on a worldwide basis. Particular emphasis is pl...

A diagnostic probe designed to investigate propagation at millimeter wavelengths was operated on 11.8 and 27.2-km line-of-sight paths near Boulder, CO. A 30.3-GHz carrier is biphase-shift-keying modulated at a 500 Mb/s with bit error rates less than ...

This report is a spectrum resource assessment of the 162–174 MHz band. Included is information on allocation, frequency assignments and agency equipment usage, along with the results of agency interviews. Present spectrum management techniques and as...

Today, three–quarters of the U.S. employment and one–half of the Gross National Product (GNP) are associated with services. In 1981, services employment predominated, for the first time, over both agriculture and manufacturing, even in the Third Worl...

Observations of the F2-region critical frequency, foF2, and values determined from,the time-dependent continuity equation for ions and electrons in the ionosphere have been used to develop a new set of numerical coefficients to represent the global v...

This report is an update of a previous report of the same title published by the former Office of Telecommunications Policy. It provides guidance to Federal system planners in securing spectrum support for proposed new or modified telecommunications ...

Since the normally assumed with Gaussian interference is the most destructive in terms of minimizing channel capacity, substantial improvement can usually be obtained if the real-word interference environment (non-Gaussian) is properly taken into acc...

The evaluation of prediction models for microwave attenuation by rainfall Jan. 1984

The neutral atmosphere is characterized for the frequency range from 1 to 300 GHz as a nonturbulent propagation medium. Attenuation and propagation delay effects are predicted from meteorological data sets: pressure, temperature, humidity, suspended ...

Analytical and empirical results concerning the relative spectrum efficiency of twogenerjc (wideband and narrowband) land mobile radio systems are presented. Graph theoretic frequency assignment techniques are used to relate spectrum usage to transmi...

American National Standard X3.102 defines a set of 21 standard parameters that provide a uniform means of specifying the performance of data communication systems and services as seen by users. This report is basically an explanation and elaboration ...

This report is concerned with the spectral representation of analog frequency modulated (FM) signals, with particular attention to frequency division multiplexing (FDM)/FM satellite communication systems. The FM spectral modeling and gaussian approxi...

Assessment of satellite power flux-density limits in the 2025-2300 MHz frequency range, Part 1, Oct. 1983

This report contains a consolidation of practical engineering equations for linear communication antennas suitable for use in the prediction and analysis of the system performance of high frequency communication equipment. The theoretical background ...

The problem of counting the occurrences of bit errors, block errors, bit additions or deletions and block additions or deletions is considered. A general method is developed for counting such occurrences for cases when the occurrences are not excessi...

The report is a primer on Integrated Services Digital Networks (ISDN's). The ISDN concept is believed by many to be the communication means for the future information age. A number of national ISDN's interconnected together can provide a high-perform...

A diagnostic probe used to fully describe the propagation characteristics of a millimeter wave channel by nearly simultaneous recording of an impulse response, frequency spectra, amplitude response, and bit error rate is discussed. A 30.3 GHz carrier...

It is demonstrated that most of the classical raindrop-size distribution formulations give inconsistent results when used to calculate specific attenuations at millimeter-wave frequencies. For this reason, it was decided it might be desirable to subc...

Although the use of transmissions that are composed of bursts of information is not new, its application in a terrestrial environment at VHF and UHF is. The usual way of expressing the variabilities in received signal level due to propagation effects...

A radio propagation prediction computer code has been developed to permit rapid simulation of HF air–to–ground telecommunication circuits. This prediction program provides estimates of both skywave and groundwave HF propagation parameters. The skywav...

A simple model of the attenuation of millimeter waves by precipitating liquid water clouds is presented. As frequency increases from the microwave band into the millimeter wave band, the model indicates a significant increase in the relative importan...

This report describes the operation and use of the Ionospheric Communications Analysis and Prediction Program (IONCAP). The computer program is an integrated system of subroutines designed to predict high-frequency (HF) skywave system performance and...

This report describes an experiment designed to measure the performance of digital microwave radio systems in a line-of-sight (LOS) link that is subject to strong atmospheric multipath. It outlines the measurements made to characterize the propagatio...

Attenuation by the atmosphere can severely limit the use of the radio spectrum above 10 GHz for telecommunication purposes. In this report brief discussions of three mechanisms that attenuate millimeter waves in the atmosphere are presented: rain att...

In this second part of an ongoing study, the general problem of optimum and suboptimum detection of threshold (i.e. weak) signals in highly nongaussian interference environments is further, developed from earlier work ([la],[lb];[34]). Both signal pr...

A review of EIA and CCITT data interface standards identifies three generations namely: first (1960's), second (1970's), and third (1980's and beyond). The User/Network physical interference for the pending Integrated Services Digital Network is an e...

This report discusses the different types of interoperability requirements, summarizes several related research and development projects, and presents alternatives for aachieving interoperability between the Defense Communications System and the TRI-...

The multiple knife-edge (MKE) attenuation function is derived from Fresnel-Kirchhoff theory and compared with the original derivation from Furutsu’s generalized residue series. It is shown that the two methods give complex attenuations with the same ...

In early 1980, NTIA, through the Interdepartment Radio Advisory Committee (IRAC) Spectrum Planning Subcommittee (SPS), became cognizant of several new major radar systems being developed by Government agencies in the 2700-2900 MHz band. In light of t...

Price of international satellite service: COMSAT vs INTELSAT, April 1983

This report presents an overview of the 1982 telephone network technology. Many physical facilities constitute the public switched telephone network. Their respective roles in support of voice services and related traffic are reviewed. Essential inte...

The meteor burst communications model is a user-interactive computer model that predicts the reliability of a communications system that uses meteor bursts as the communications channel. The model predicts the waiting times required to complete the t...

This report is a Spectrum resource Assessment of the 5650-5925 MHz band. Included in information on rules and regulations, allocations, technical standards, frequency assignments, system characteristics, and applicable compatibility analysis.

An integral equation method is presented for computing the vertically polarized field strength over irregular terrain which is covered with forest, buildings, or snow. The terrain cover is modeled as an equivalent slab, and a general computer code, W...

Comparisons of theoretical attenuation based on multiple knifeedge diffraction with measured values of median propagation loss are presented for a number of different propagation paths. In general the knife-edge predictions tend to overestimate recei...

This report describes use of the revised computer program FOOTPRINTS. The program automatically computes and plots earth footprints and service area polygons on a map projection of the earth's surface. The program can be used as a design tool to maxi...

The burning of an Atlas-Centaur rocket in the ionospheric F–region was used to determine the extent of HF propagation anomalies associated with the resultant drop in ionospheric electron content. This "ionospheric hole" grew to encompass the control ...

General Docket 81-414, Notice of Inquiry and Proposed Rulemaking, proposes allowing the Amateur Radio Service to use spread spectrum techniques in three bands. This report reviews the Docket's proposals and the public's reaction, reviews direct seque...

This report presents the results of a trial implementation of a newly developed data communication performance measurement methodology which has been proposed as Federal Standard 1043. In this experiment, a prototype data communication performance me...

The Forest Service is in the process of updating its telecommunication and information systems. Included in this update are proposed changes to the telephone systems of selected National Forests with an eye toward telephone cost reductions over curre...

PRODSIR is a procedure for computing the probability distribution of the signal-to-interference ratio in a congested radio environment. Most of the independent variables in the usual signal-to-interference equation are assumed to be random variables,...

This report presents an extensive bibliography, categorized by effect, of radio propagation through the atmosphere, for the frequency region of 10 to 300 GHz. Preceding the bibliographic presentation is an article-by-article synopsis of that literatu...

The Regional Administrative Radio Conference will be convened in 1983 for planning broadcasting-satellite service in the International Telecommunication Union Region 2 to resolve the issue of allocating orbital positions and radio frequencies in the ...

Pollard (1975) describes a "Monte Carlo" factoring algorithm based on iterating some specific quadratic polynomials. In this paper different polynomials are tested in the algorithm to see if a more efficient factoring can be obtained. The results are...

In the MF band, interfering signals from one or more broadcast stations can be received. During nighttime periods, this interference is caused by fading signals, propagated from distances of more than about 200 miles. It is the purpose of this report...

National and international work toward an Integrated Services Digital Network (ISDN) and the progress toward its implementation is described. Standards activity and technology relating to the ISDN, in the United States and abroad, are presented.

Privacy protection law in the U.S., May 1982

The ITS model of radio propagation for frequencies between 20 MHz and 20 GHz (the Longley–Rice model) is a general purpose model that can be applied to a large variety of engineering problems. The model, which is based on electromagnetic theory and o...

The possibility of an Integrated Services Digital Network (ISDN) encircling the globe by the year 2000 is of increasing interest to the worldwide telecommunication community—developers, carriers, manufacturers, and users. Accelerating telecommunicati...

This report summarizes techniques that use the measured instantaneous envelope statistics of arbitrary noise or interference processes to calculate the degradation these processes cause to digital communication systems. Computer implementation of the...

This report describes a laboratory experiment which was conducted to find out if the absolute attenuation of a 35 GHz signal by the molecular species H2O2 (hydrogen peroxide), HN03 (nitric acid), N02 (nitrogen dioxide), N2O (nitrous oxide) exceeds a ...

The geographic coverage of all telephone companies in the United States is presented in a series of maps depicting the operating areas served by Bell and each of the various independent telephone companies. Tables are also presented of state-by-state...

Satellite communications are likely to be used to provide thin–route telephone service in developing countries only if the cost of earth stations can be substantially reduced. A parametric analysis of earth–station design and service capabilities is ...

The Institute for Telecommunication Sciences has embarked upon a program to improve the techniques that are used to determine medium frequency broadcasting parameters. This work is motivated by the fact that increased transmitter power which is plann...

During the past several years, the Radio Spectrum Measurement System (RSMS) of the National Telecommunications and Information Administration (NTIA) has measured the emission spectra and other characteristics of many radars operating in the governmen...

In this report, the results of a study to improve the global maps of monthly median values of the F2 region critical frequency, foF2, using values determined from a theoretical model, are presented. The object of the study was to obtain values of the...

A model of the parameters that specify the structure of the electron density in the polar ionosphere has been developed. The model is based upon the modification of monthly median ionospheric parameters given by the CCIR by use of formulations that c...

Elevated Duct Data-Base Improvement, Dec. 1981

Starting from work by Furutsu, a multiple knife-edge attenuation function is derived. A series representation of the function is developed which is amenable to computer implementation. Comparisons of computer-generated numerical values with known res...

The purposes of this study (and subsequent efforts) are several: (1), to extend earlier models of the FM reception process, to include as much II "realism" – i.e., non-ideality of both the linear and nonlinear elements of the typical FM receiver – as...

The 1977 World Administrative Radio Conference for the Planning of the Broadcasting-Satellite Service decided that elliptical antenna beams should be used for satellite antennas for planning purposes. Since it is desirable to minimize the antenna bea...

Spectrum resource assessment in the 2300-2450 MHz band, Sep. 1981

Spectrum resource assessment in the 1660-1710 MHz band, Sep. 1981

The report is a study and primer of the discrete logarithm public key cryptographic system. Implementation and strengths and weaknesses are discussed.

Spectrum resource assessment in the 4400-4990 MHz band, Sep. 1981

Spectrum resource assessment in the 1215-1400 MHz band, Sep. 1981

This report presents the description, analysis and results of a set of measurements made on a 90 km line-of-sight path in Italy. The measurements were made during the late spring of 1980 by the National Telecommunications and Information Administrati...

Spectrum Resource Assessment in the 216-225 MHz Band, Sep. 1981

Several of the public-key cryptosystems that received considerable publicity are examined. The uses, implementation, and potential cryptoanalytic attacks are discussed. Since most of the suggested systems depend on the manipulation of large numbers, ...

This is a companion document to another NTIA Report, "Proposed Techniques for Adding FM Broadcast Stations in a Major Market". Increasing the number of assignments is possible if: 1) co–siting of second– and third–adjacent–channel transmitters is all...

The large amount of power contained in the main beam and principal sidelobes of the proposed Solar Power System (SPS), now under study by DOE and NASA, potentially presents an EMC problem for other satellite systems. This report examines selected geo...

The Department of Energy (DOE), along with the National Aeronautics and Space Administration (NASA), has been evaluating the Satellite Power System (SPS) as a source of baseline electrical power. The objective of the SPS program is to develop an init...

This report is the sum of a three–part effort by the Institute for Telecommunication Sciences (ITS) to provide technical recommendations for the DCS Long–Haul Tactical Common system, subsystem, and equipment technical standards for digital radio. The...

Final Report The NTIA rural communities field studies, April 1981

Trade Issues in Telecommunications and Information: Volume I. United States Trade in the Merchandise of Information Industries

Trade Issues in Telecommunications and Information: Volume II. The Employment Effects of Trade in High-Technology Telecommunications and Information Products

Trade Issues in Telecommunications and Information: Volume III. Promoting U.S. Trade in Telecommunications and Information Products with Developing Countries

Trade Issues in Telecommunications and Information: Volume IV. The Role of the United States Government in the Financing of Exports of Major Telecommunications and Information Products

Guidelines for interconnection to the United States Postal Service (USPS) Electronic Computer Originated Mail (E-COM) System via telecommunications carriers are developed. Adescription of the E-COM System is given and the need for telecommunications ...

Radio wave interaction measurements using the high power transmitter at Platteville have resulted in cross modulation of up to 30% as compared to the earlier cross modulation measurements of 7% or less at low power. A theory is derived which shows th...

The International Record Carriers have, for a number of years, provided a switched, overseas, voiceband data service called Datel. This report examines changes required in the Bell/Independent domestic MTS network to provide a more advanced form of i...

Throughout an area between Chicago and Peoria, Illinois, approximately 50 measurement locations were selected. At each location measurements were made, typically, for two VHF television broadcasts from Chicago and three UHF television broadcasts from...

This report categorizes the manner in which atmospheric stratification can complicate the problems of frequency allocation and radio regulation by inhibiting service fields and enhancing interference fields. For the United States and its border regio...

TOPOG is a computerized worldwide terrain elevation data base generation and retrieval system. It consists of software to generate TOPOG tapes from Defense Mapping Agency (DMA) standard terrain elevation data tapes, to create auxiliary random–access ...

This report describes the effort which will be undertaken to determine telecommunication standards necessary for interconnection to the United States Postal Service (USPS) planned long-range Electronic Mail Service System (EMSS). This work is in comp...

Interference to radio receivers, such as those used in radio astronomy, can present problems. Adding conventional filters to a radio astronomy receiver's input generally results in an appreciable increase in noise temperature if the filters have any ...

The solar power satellite (SPS) is a concept for generating electrical power from solar energy via a geosynchronous orbiting satellite. A facility, such as this, would be able to send approximately 5 to 10 gigawatts of power to earth on a highly focu...

The concept of collecting solar energy in an orbiting, geostationary, solar power satellite (SPS) and then beaming this power to earth via a focused microwave beam at 2.45 GHz has received considerable attention in recent years. This report examines ...

As with many technologies, the evolution of telecommunication systems is shaped by two driving forces – performance and cost. There is a real need to bridge the gap between 'performance' as perceived by the user in accomplishing a mission and 'perfor...

An automated, computer–controlled receiver system developed by ITS for the U.S. Army Communications Command provides a unique solution to such problems as spectrum management, EM hazards measurements, and site surveying. This receiving system is desi...

Thia report ia based on published cost figures of the TAT-6 submarine coaxial cable system which went into service on July 27, 1976. Assuming readiness of long wavelength (1300 nm) devices by the late 1980s, we project the expected cost of a fiber ca...

This report presents the results of mobile measurements of VHF signals in the Denver, Colorado, urban environment. The signals monitored were those received from the TV transmissions of KBTV (Channel 9), KMGH (Channel 7), KOA (Channel 4), and KWGN (C...

There is a growing need within the Federal government for a user-oriented, system-independent, functional means of specifying data communication performance. A recently published Federal Standard, Interim Federal Standard 1033, defines a set of stand...

Interference caused by local oscillator radiation from AM radios is a known problem. It is particularly troublesome when the local oscillator frequency of one radio coincides with the tuned frequency of another, nearby AM radio. This condition produc...

Evaluation of Discrete Address Beacon Systems (DABS) EMC, Nov. 1980

Measurements of the amplitude probability distributions and the average crossing rates of the electromagnetic noise radiated by automotive ignition systems were made at 30 MHz, 47 MHz, 147 MHz, 224 MHz, and 445 MHz. The ignition noise from a single c...

A new, consumer–oriented family of innovative information distribution services, generically termed VIDEOTEX, is being offered to the European and Japanese public. Several field trials are underway in the U.S. Normally using a modified home TV receiv...

This report discusses microwave engineering data relevant to assess the potential of the Satellite Power System (SPS) to cause microwave field enhancements (so called "hotspots") inside habitable structures (house, trailer, car, etc.) located in the ...

This report describes methods for calculating, under certain simplifying assumptions, footprints (contours of constant power density) for idealized models of several common types of transmitting antennas (circular aperture, elliptical aperture, recta...

The radio coverage for two maritime distress communication systems are calculated for those U.S. Coast Guard stations in the contiguous United States. The two systems are: the international MF distress channel and the international VHF distress chann...

This report describes the spectrum resource assessment of the 1710–1850 MHz band. The Phase I Report [Hurt and Crandall, 1980] provided information on frequency allocations, technical standards, spectrum usage, and identification of key spectrum mana...

Spectrum resource assessment in the 2200-2300 MHz band, Sep. 1980

A study was conducted to investigate the technical capacity of the FM broadcast spectrum and to determine if the FM spectrum's utilization could be increased. More assignments are possible if some or all of the following recommendations are adopted: ...

The radio wave propagation path between an earth station and a synchronous satellite 1s described by engineering-type formulas which consolidate all of the known external elements significant for system performance. This UHF/SHF consolidated model, a...

An experimental study of atmospheric multipath on a 23 km link at 9.6 and 28.8 GHz near Boulder, Colorado, is described. The preliminary observations were made for three days in July 1979 when a strong inversion layer was present, creating an elevate...

Middleton's analytical formula for the probability of communications in a land mobile environment and Berry's computer program for probabilistic calculations of interference are shown to produce identical answers for identical inputs. The assumptions...

The chronological development of the available methods for predicting medium frequency sky–wave strengths is presented with a brief discussion of each method. Measured field strengths for 36 medium frequency sky–wave paths are compared with the predi...

Measurements of the voice intelligibility over landmobile systems in the presence of vehicle noise are presented. These are compared with several statistical noise parameters obtained from measured amplitude probability distributions.

The pressure to provide additional full-time facilities in the AM (standard broadcasting) band in the United States resulted in a rulemaking petition filed with the Federal Communications Commission (FCC) by the National Telecommunications and Inform...

The communications network structures currently used to interconnect terminal clusters and switching nodes within an Army tactical command post and area signal center are reviewed. With this background, five alternative structures are defined in term...

This report summarizes the results of experiments undertaken to assess the potential impact of the operation of the Satellite Power System on the D and E regions of the ionosphere, and on telecommunication systems that are dependent upon the structur...

The National Telecommunications and Information Administration (NTIA) in the Department of Commerce undertook a detailed program to investigate the feasibility of deploying the Limited Surveillance Radars (LSR) in the 2.7-2.9 GHz band in the Los Ange...

Radio noise of ground-based origin can be observed by a satelliteborne receiver orbiting above the 2 region. The noise that is observed is a function of receiver frequency, satellite position, and local time at the sub-satellite point. A recently lau...

In military base access areas, akin to many commercial installations, the telecommunications traffic passes through several concentration and switching stages. Loads to server facilities are formed through mergers and branch outs of offered traffic s...

A study was conducted to determine the limiting propagation effects on the performance of a microwave system that could be used to detect the optical visibility between two vehicles, separated by up to 10 km, in irregular, obstructed terrain. The stu...

The United States Administration has proposed for the 1979 WARC (World Administrative Radio Conference) to move the BSS (broadcasting–satellite service) in ITU (International Telecommunication Union) Region 2 from the band 11.7-12.2 GHz to the band 1...

This paper discusses measurement of signals received over a 160-km (100-mile) line-of-sight microwave radio link operating at 8.4 GHz. Signals were recorded at both ends of the path at various times over a period of about 18 months. The effects of ma...

This report investigates the performance of an FM, landmobile, receiver in FM interference. Measurements are described showing the effects of multiple interfering FM signals as a function of modulation index, signal-to-interference ratio, signal-to-n...

The ability of a television receiving antenna to deliver adequate signal power to the terminals of its receiver is determined by its gain relative to a lossless half-wave dipole antenna. This report presents measured gain data for indoor television r...

The bit–error–probability performances of HF digital radio systems with respect to channel and equipment additive, multiplicative, and nonlinear distortions are evaluated with respect to the nine system design features that affect the performances. T...

This report describes instrumentation for fading studies and measurement results over an 88-km multiple-diversity line-of-sight microwave link across the English Channel operating in the 4 to 5 GHz frequency range. Signal level and fade, duration sta...

The capacity of a digital circuit switching system is defined in terms of its four major elements: the traffic offered by the interface element, the maximum traffic carried by the switch matrix, the maximum number of call attempts handled by the cont...

The possibility of overlaying a spread-spectrum system into frequency bands containing conventional FM land-mobile systems is examined. Overlaying here is interpreted as meaning the unrestricted operation of spread-spectrum and FM mobiles throughout ...

This report describes an experiment conducted over a LOS microwave link off the coast of southern California. The objective was to determine the effect of known anomalous propagating conditions, caused by persistent temperature inversions in the atmo...

The National Telecommunications and Information Administration (NTIA) in the Department of Commerce undertook a detailed program to investigate the signal processing properties of the primary radars in the 2.7 to 2.9 GHz band, and the Automated Radar...

Statistical methods are provided for estimating time and rate parameters of digital communication systems according to the specifications of the Proposed Federal Standard 1033. The methods may be applied to delay, disengagement, transfer and service ...

Relative gain of fifteen television receiving antennas was measured as a function of frequency and azimuth angle. Input voltage standing-wave ratio was measured as a function of frequency to determine the scalar impedance properties of the antennas. ...

An algorithm (PROGRAM WAGNER) that evaluates HF ground–wave attenuation over irregular, inhomogeneous terrain is used to compare calculated field strengths with observed measurements for 9 actual paths and frequencies ranging from 120 kHz to 50 MHz. ...

This report describes a desk-top computer system and mathematical models which were used in seven of its programs. These programs make key calculations in the design of line-of-sight microwave systems. The models have the following ranges; bit rates ...

This report summarizes activities associated with the Federal Government's program to assess the biological effects of nonionizing electromagnetic radiation being coordinated by the National Telecommunications and Information Administration (NTIA). I...

Strong electromagnetic (EM) energy sources up into the microwave range are examined and estimates are made of maximum EM field conditions to which automobiles could be exposed. The results are meant to alert automotive engineers to potentially hazard...

A software package of programs has been developed which automatically measures and analyzes the received signal level of four microwave communication receivers. The package will run on the Test and Acceptance Calculator Instrumentation which the USAF...

A number of factors, including network topology, traffic characteristics, switching technology, and transmission media, affect the choice of control signaling techniques to be used in networks of the future. In this report these factors are considere...

Conversion to digital transmission has renewed the concerns about what effects aircraft obstruction of microwave links have on user quality. This is of particular concern where it is necessary to install a telecommunication system that crosses runway...

The sole purpose of this publication is to provide the public with a list of existing computer aids for the evaluation of radio systems which operate in any part of the radio spectrum. Consequently, neither the Department of Commerce (DoC), nor t...

The use of spread-spectrum modulation in a common type of land-mobile radio service is studied. The radio service contains many networks operated independently, similar to the business land-mobile radio service. Network independence implies (among ot...

Measurements of radio propagation path loss and local ground conductivity were made over four paths in the 100 to 2000 kHz band. The paths were of lengths up to 50 km and were chosen to represent both extreme and typical topography and conductivity c...

The previously developed Rice-Holmberg (RR) rainrate model and the Dutton-Dougherty (DD) attenuation model for earth-space links, and their subsequent modifications, are reviewed. Predictions are compared with data observed both from the Communicatio...

Methods of determining the first-order parameters of both the approximate and exact Class A and B models are derived, for both the ideal case of infinite sample data the practical cases of finite data samples. It is shown that all (first order) param...