Institute for Telecommunication Sciences FY 2011 Technical Progress Report

ITS Organization Chart

Office of the Director Al Vincent, Director Lisé C. Matthews, Administrative Specialist Jill V. Copeland, Secretary

Administrative Office Brian D. Lane, Executive Officer Carol B. Van Story, Budget Analyst Lilli Segre, Publications Officer Lawrence Turner, IT Specialist

Spectrum and Propagation Telecommunications Measurements Division Engineering, Analysis, and Eric D. Nelson, Chief Modeling Division Ruth Chillemi, Secretary Patricia J. Raush, Chief

Telecommunications and Telecommunications Theory Information Technology Division Planning Division Frank H. Sanders, Chief Jeffrey R. Bratcher, Chief Amy Weich, Secretary Kathy Mayeda, Secretary

Institute for Telecommunication Sciences National Telecommunications and Information Administration U.S. Department of Commerce 325 Broadway Boulder, CO 80305-3328 303-497-5216 http://www.its.bldrdoc.gov Institute for Telecommunication Sciences FY 2011 Technical Progress Report

U.S. Department of Commerce Lawrence E. Strickling, Assistant Secretary for Communications and Information May 2012 Certain commercial equipment, components, and software are identified in this report to adequately describe the design and conduct of the research and experiments at ITS. In no case does such identification imply recommendation or endorsement by the National Telecommunications and Information Administration, nor does it imply that the equipment, components, or software identified are necessarily the best available for the particular application or use. All company names, product names, patents, trademarks, copyrights, or other intellectual property mentioned in this document remain the property of their respective owners.

Cover art by A.D. Romero. ii Contents

The Institute for Telecommunication Sciences ...... 1 ITS Overview ...... 2 Awards and Honors ...... 5 Spectrum and Propagation Measurements ...... 7 Radio Noise and Spectrum Occupancy Measurement Research ...... 8 RSMS Development ...... 10 RSMS Operations ...... 12 Spectrum Sharing Innovation Test Bed Pilot Program ...... 14 Table Mountain Research Program ...... 16 Telecommunications and Information Technology Planning . 19 Multimedia Research ...... 20 Project 25 Compliance Assessment Program ...... 22 Project 25 Standards Development ...... 24 Public Safety Audio Quality ...... 26 Public Safety Broadband Demonstration Network ...... 28 Public Safety Broadband Research ...... 30 Telecommunications Engineering, Analysis, and Modeling . .33 Interference Issues Affecting Land Mobile Systems ...... 34 Public Safety Video Quality (PSVQ) ...... 36 Fading Characteristics Verification ...... 38 Telecommunications Analysis Services ...... 40 Propagation Modeling Website ...... 42 Broadband Wireless Standards ...... 44 Integration of the Empirical and the Undisturbed-Field Models ...... 46 Earth-to-Space Propagation Models ...... 48 Telecommunications Theory ...... 51 Audio Quality Research ...... 52 Broadband Wireless Research ...... 54 Coast Guard Spectrum Reallocation Study ...... 56 Effects of the Channel on Radio System Performance ...... 58 Interference Effect Tests, Measurements, and Mitigation for Weather Radars . . . .60 Lockheed Martin Radar Measurement CRADA ...... 62 U.S. Navy Shore Line Intrusion Monitoring System (SLiMS) Emissions Measurements . 64 Video Quality Research ...... 66 Technology Transfer ...... 68 FY 2011 Private Sector CRADAs ...... 70 ITU-R Standards Activities ...... 72 ITU-T and Related U.S. Standards Development ...... 74 ITS Publications and Presentations in FY 2011 ...... 76 ITS Standards Leadership and Contributions ...... 82 ITS Tools and Facilities ...... 84 ITS Projects in FY 2011 ...... 96 Abbreviations/Acronyms ...... 102

iii iv Mission The Institute for Statements Telecommunication Sciences The Department of Commerce creates he Institute for Telecommunication Sciences (ITS) is the research and engineering laboratory the conditions for Tof The National Telecommunications and Information Administration (NTIA), an agency of economic growth the Department of Commerce (DOC). ITS performs basic research in radio science that provides the and opportunity by technical foundation for NTIA’s policy development and spectrum management activities. promoting ITS research enhances scientific knowledge and understanding in cutting-edge areas of tele- innovation, communications technology. The Institute’s research capacity and expertise is used to analyze new entrepreneurship, and emerging technologies, and to contribute to standards creation. Research results are broadly competitiveness, disseminated through peer-reviewed publications as well as through technical contributions and and stewardship recommendations to standards bodies. ITS staff represent U.S. interests in many national and inter- informed by national telecommunication conferences and standards organizations. Through leadership roles in world-class various working groups, ITS helps to influence development of international standards and policies scientific research to support the full and fair competitiveness of the U.S. communications and information technology and information. sectors. ITS research helps to drive innovation and contribute to the development of communications and broadband policies that enable a robust telecommunication infrastructure, ensure system The National integrity, support e-commerce, and protect an open global Internet. Telecommunica- tions and Information Administration (NTIA) serves as the President’s principal adviser on telecommunications and information policy matters, and develops forward looking spectrum policies that ensure efficient and effective spectrum access and use.

The Institute for Telecommunica- Commerce Secretary John Bryson (second from left) visits the Public Safety Communications tion Sciences (ITS) Research (PSCR) laboratory at ITS. Captain Paul Roberts of the Boise, Idaho, Fire Department (far performs telecom- right) and Lieutenant Ken Link of the Monroe Township, New Jersey, Fire Department (second munications from right) were in the lab to participate in ongoing subjective testing experiments conducted research, conducts by the Public Safety Video Quality (PSVQ) project. PSCR is a multi-agency project that directly cooperative supports DOC Strategic Objective 13: “Enhance scientific knowledge and provide information to research and stakeholders to support economic growth and improve innovation, technology, and public safety.” development with ITS Division Chief Jeff Bratcher (center left) co-directs the PSCR project with Dereck Orr (far left) of U.S. industry and the National Institute of Standards and Technology Law Enforcement Standards Office (NIST/OLES). academia, and The work is sponsored by the Department of Homeland Security Office for Interoperability and provides technical Compatibility (DHS OIC) and the Department of Justice (DOJ) Community Oriented Policing Ser- engineering vices (COPS) Office, Federal agencies to whom ITS provides technical engineering support as part support to NTIA of NTIA’s mission objective to collaborate with them to begin developing a nationwide interoper- and other Federal able Public Safety Broadband Network. Photo by Will von Dauster, NOAA. agencies.

1 ITS serves as a ITS Overview principal Federal resource for the Outputs conduct of basic research on the • Explore, understand, and improve the use of telecommunication technologies and nature of radio principles waves. Technology • Solve telecommunications challenges for other Federal agencies, state and local transfer helps Governments, private corporations and associations, and international organizations private entities • Develop and influence national and international standards and policies adapt and commercialize • Investigate and invent new information and telecommunication technologies ITS research to • Address emerging telecommunications, information technology, and security enhance existing challenges telecommunica • Promptly disseminate research results via the most effective media, while maintaining tions products and the highest standards of quality, accuracy, and technical soundness services and develop new ones. A National Research Resource Organization About half of our research programs are The Institute’s technical activities are orga- undertaken for and with other Federal agen- nized into four divisions, which characterize cies; state, local and tribal governments; private ITS’s centers of excellence: corporations and associations; or international • Spectrum and Propagation Measure- organizations. Sponsored research contributes ments: designs, develops and operates state- to NTIA’s overall program and supports the of-the-art spectrum measurement systems; goals of the DOC. measures spectrum occupancy trends and Government agency sponsors that provide emission characteristics of Federal transmit- significant support include the National Insti- ter systems; identifies and resolves radio fre- tute of Standards and Technology’s Office of quency interference involving Federal systems. Law Enforcement Standards, the Department • Telecommunications and Information of Homeland Security, the Department of Technology Planning: plans and analyzes Transportation, the Department of Defense, the telecommunications and information techno National Archives and Records Administration, logy systems and services, improving their and the National Weather Service. efficiency and enhancing their performance Industry-Sponsored Research and reliability; e.g., Project 25 radios and their interoperability in public safety environments. ITS supports private sector telecommunica- • Telecommunications Engineering, tions research through cooperative research and development agreements (CRADA). CRADAs Analysis and Modeling: performs technical were authorized by the Federal Technology assessments of existing, new, and proposed in- Transfer Act of 1986 to encourage sharing of dividual telecommunication systems; analyzes Government facilities and expertise as an aid in ways to improve the efficiency and enhance the commercialization of new products and ser- the technical performance of telecommunica- vices. ITS is a member of the Federal Laboratory tions systems; and develops propagation pre- Consortium for Technology Transfer, the nation- diction models for use in multiple applications. wide network chartered by the Act to promote • Telecommunications Theory: develops in- and strengthen technology transfer. novative telecommunication technologies and ITS has entered into CRADAs with other engineering tools through the application of research organizations as well as with telecom- electromagnetic theory, digital signal process- munications service providers and equipment ing, broadband wireless systems performance, manufacturers—companies ranging from multi- audio and video quality assessment, spectrum nationals to small start-ups. These partnerships sharing concepts, and noise analysis. enhance synergies between entrepreneurial The Director’s Office supports these areas in ventures and broad national objectives. budget and administrative functions.

2 ITS Overview

Capabilities and Expertise Benefits ITS world-class ITS is one of the world’s leading laboratories The Institute’s research significantly benefits facilities and capabilities for telecommunications research. Its staff of both the public and private sectors. include: electronics engineers, mathematicians, physi- • Spectrum Utilization: ITS research supports • Audio-Visual cists, computer scientists, and administrators optimization of Federal spectrum allocation Laboratories have strong engineering and scientific skills and methods by identifying unused frequencies • Public Safety RF experience. ITS’s areas of expertise include: and potential interference through field mea- Laboratory • Radio Research and Spectrum Measure- surements, and by promoting technology ad- • Public Safety ment: ITS designs, develops and operates vances to aid in efficient use of the spectrum. Audio & Video state-of-the-art spectrum measurement sys- • Telecommunications Negotiations: ITS Laboratories tems to measure spectrum occupancy trends provides expert technical leadership at interna- • Radio Spectrum and emission characteristics of Federal trans- tional conferences and develops engineering Measurement mitter systems, and to identify and resolve ra- tools such as interference prediction programs Science (RSMS) dio frequency interference in Federal systems. to support negotiations. Program • Communication Systems and Networks: • Public Safety: ITS provides systems engineer- • Table Mountain ITS plans, implements, and evaluates telecom- ing, planning, and testing of interoperable Field Site/Radio munication systems and networks. radio systems (e.g., voice, video, and data) for Quiet Zone • Public Safety Interoperability: ITS facilitates the use of “first responders” at Federal, State, • Telecommunica inter-connectivity and interoperability between local, and tribal levels. tions Analysis services and technologies used by public safety. Services • Standards Development: ITS contributes to Read more about voluntary consensus standards development these and other by providing leadership and technical contri- resources at ITS in butions in national and international telecom- the ITS Tools and munication standards committees. Facilities section, • Wireless Voice/Data Systems and Emerg- page 84. ing Technologies: ITS assesses telecommunications system components, evaluates network • National Defense: ITS research contributes survivability, and assesses system effectiveness to the strength and cost-effectiveness of the in national security, emergency preparedness, U.S. Armed Forces through improvement of military, and commercial environments. The network operation and management, en- Institute tests emerging technologies such as hancement of survivability, expansion of net- Voice over IP (VoIP), ultrawideband, and Dy- work interconnections and interoperation, and namic Spectrum Access (DSA). improvement of emergency communications. • Audio and Video Quality Research: ITS • Domestic Competition: ITS develops user- conducts research on digital audio and video oriented, technology-independent methods of quality, grounded in signal processing theory measuring telecommunications performance and models of perception. to give users a practical way of comparing • Electromagnetic Modeling and Analysis: competing equipment and services. ITS maintains ongoing investigations in broad- • International Trade: ITS participation facili- band wireless systems performance, propa- tates promulgation of international telecom- gation model development incorporating munications standards, removing technical field measurement data, advanced antenna barriers to U.S. export of telecommunications designs, and noise as a limiting factor for ad- equipment and services. vanced communication systems. • Technology Transfer: Direct transfer of • IT Prototyping and Security Analysis: ITS research results and measurements from ITS applies its security expertise to current and to U.S. industry and Government supports emerging Internet technologies through the national and international competitiveness, design and implementation of prototype brings new technology to users, and expands information systems, including large scale the capabilities of national and global tele- records management infrastructure. communications infrastructures.

3 In FY 2011, research performed by ITS helped ensure that planes land safely, first responders can communicate with each other, and the U.S. Department of Defense can optimize deployment of communications systems—among many other things. ITS released 11 NTIA technical memoranda, reports, or handbooks and Figure 1. Commerce Secretary John Bryson (far left) presented a Silver Medal Award to (left to four articles by ITS right) Jeff Bratcher, Dereck Orr (NIST/OLES), Eric Nelson, John Vanderau, Robert Stafford, and Ron researchers were Carey. Acting Deputy Secretary of Commerce Rebecca Blank (third from right), Assistant Secretary accepted by for Communications and Information and NTIA Administrator Larry Strickling (second from right), refereed scientific and Under Secretary of Commerce for Standards and Technology and NIST Director Patrick Gal- publications. lagher (far right) assisted in the presentation. Photo courtesy Department of Commerce.

Figure 2 (left). Jeff Bratcher and Andrew Thiessen receive a Bronze Medal award during a video-conference ceremony; the simultaneous presentation to their team members in Washington D.C. is being videocast behind them. Figure 3 (below). PMW team members (from left to right) Teresa L. Rusyn, Julie E. Kub, George Engelbrecht, and Kristen E. Davis, receiving the Bronze Medal award. Photos by Lilli Segre.

4 Awards and Honors

Since 1949, the Awards and Honors Department of Commerce has en ITS employees received Gold or Silver Medals and nine employees on two ITS teams and granted honor one NTIA inter-office team received Bronze Medals for work completed in FY 2011. T awards in the form Gold Medal Award of Gold, Silver, and The U. S. Department of Commerce Gold Medal award is the highest Bronze Medals. honorary award given by the Department. The award is granted by the Gold and Silver Secretary for distinguished performance characterized by extraordinary, Medals are granted notable, or prestigious contributions that impact the mission of the by the Commerce Department and/or one operating unit and that reflect favorably on the Secretary; the Department. Bronze Medal is An interdepartmental, inter-agency team from NTIA and the National granted by the Institute of Standards and Technology (NIST), which included ITS Infor- head of an mation Technology Specialist Michael Ossman, received Gold Medals in the category of Personal and operating unit or Professional Excellence for their work as part of an international effort to deploy the Domain Name Secretarial Officer. System Security Extensions (DNSSEC) at the Internet’s authoritative root zone. The group performed exceptional service to the Department and the U.S. by enhancing the accuracy and integrity of information supplied by the DNS that is essential to the operation of systems and services using the Internet. The accomplishment assures continued stability and security of the Internet and continued private sector investment and innovation. Silver Medal Award Bronze Medal Awards The Silver Medal The Bronze is the second high- Medal is granted est honorary award by the head of an given by the Depart- operating unit or ment, and is granted Secretarial Officer by the Secretary for for superior per- exceptional perfor- formance. This year’s recipients were: mance character- • Jeff Bratcher, Andrew Thiessen and eight other ized by noteworthy or superlative contributions team members from five different offices of that have a direct and lasting impact within the NTIA received Bronze Medals for furthering Department. President Obama’s Wireless Innovation and An inter-divisional and inter-agency team Infrastructure Initiative goal of establishing led by Public Safety Communications Research a single, nationwide public safety wireless (PSCR) program Co-Managers ITS Division Chief broadband network (Figure 2). Jeff Bratcher and NIST Office of Law Enforce- • The four members of a multidisciplinary team ment Standards (NIST/OLES) Management and from the Telecommunications Engineering, Program Analyst Dereck Orr (Figure 1) received Analysis, and Modeling Division (Figure 2) re- Silver Medals in the Leadership category for ceived Bronze Medals for development of the leading the inter-agency effort to develop and Propagation Modeling Website (PMW) through implement the Project 25 (P25) Compliance As- other agency work for the Department of De- sessment Program (CAP) to meet public safety’s fense. The work is described on page 42. need for objective evidence that specific land • John Carroll, Steve Engelking, and Geoffrey mobile radio (LMR) systems meet standards of Sanders received Bronze Medals for designing performance and interoperability. The P25 CAP and deploying an advanced new Radio Spec- program, described on page 24, is one of five trum Measurement Science (RSMS) system in principal technical and research programs at ITS support of critical radio spectrum measure- that are focused on fostering nationwide in- ment in less than two years. RSMS develop- teroperability of public safety communications. ment efforts are described on page 10.

5 The White House, Presidential Memorandum: Unleashing the Left: ITS measurement van Wireless undergoing emissions testing Broadband in an anechoic chamber. Revolution, Photo courtesy of EMC June 28, 2010:1 Integrity.

Few technological developments hold as much potential to enhance America’s economic competitiveness, create jobs, and improve the quality of our lives as Right: EQ-36 Counterfire Target wireless high-speed Acquisition Radar undergoing access to the emissions measurement. Photo by Internet. Frank Sanders.

We can also unlock the value of otherwise underutilized spectrum and open new avenues for spectrum users to derive value through the Left: Engineers Bob Johnk development of and Paul McKenna and Intern advanced, Linh Vu (left to right) make situation-aware adjustments to an antenna spectrum-sharing used to measure soil electrical technologies. properties. Photo by Wayde Allen.

Right: A dynamic frequency selection access point being field tested with radars at the FAA Aeronautical Center in Oklahoma City, OK. Photo by Frank 1. http://www.whitehouse. Sanders. gov/the-press-office/ presidential-memorandum- unleashing-wireless- broadband-revolution

6 Spectrum and Propagation Measurements

The Secretary of Spectrum and Propagation Commerce, Measurements working through NTIA … shall n June 2010, President Obama released a Memorandum entitled “Unleashing the Wireless Broad- create and Iband Revolution.” The memo highlighted the need for innovative spectrum-sharing techniques implement a plan to increase spectrum efficiency to sustain critical Government radio operations while permitting dra- to facilitate matic increases in commercial spectrum use. The Spectrum and Propagation Measurements Division research, directly supports this mandate through research and experimentation that provides insights into development, spectrum use and radio system compatibility, which informs the spectrum policy making process. experimentation, The division’s engineers conduct measurements of spectrum usage and occupancy, assess the and testing by compatibility of disparate radio systems, develop and conduct conformity assessment tests, char- researchers to acterize system noise, and measure receiver performance criteria. The following areas of emphasis explore innovative are indicative of the work done recently in the division to support NTIA, other Federal agencies, spectrum-sharing academia, and private industry. technologies, including those Radio Spectrum Measurement at this site includes development and evalua- that are secure and Science (RSMS) Program tion of measurement methods for spectrum resilient.  The RSMS program develops and operates occupancy, radio noise, antenna design, laser an automated testing capability that is adapt- testing, and radar emissions. Work is supported able to a wide variety of measurement sce- by ITS funding as well as cooperative research narios. Composed of commercial and custom and development agreements with non-Federal test equipment, the RSMS system supports ad entities. hoc measurements to assess and resolve com- Spectrum Sharing Innovation plaints of interference involving Government Test Bed Pilot Program radio systems, conducts both comprehensive Dynamic Spectrum Access (DSA) technol- and band-specific spectrum surveys, measures existing and proposed radio system emissions ogy promises greater frequency agility and for electromagnetic compatibility studies, and improved radio adaptation to the environment performs ongoing conformance tests on radio for increased spectrum efficiency. The division is systems. RSMS projects funded by ITS cover presently spearheading Test Bed measurements incremental enhancements and maintenance of to assess the capabilities of state-of-the-art DSA the system, the development of new capabili- devices. The project is funded by NTIA/OSM. ties, and operational deployments. Radio Noise and Spectrum Table Mountain Research Occupancy Measurement Program Research The Table Mountain Field Site is the principal ITS engineers are developing a noise measure- experimental field site for the Department of ment system based on Vector Signal Analyzer Commerce Boulder Laboratories. Designated (VSA) technology. VSA technology captures by Congress as a protected radio quiet zone magnitude and phase information and allows where the magnitude of external signals is for wider bandwidth noise measurements than restricted, the site facilitates various advanced those historically conducted at ITS. The project research and measurement programs. Research is funded by ITS. For more information contact: Eric D. Nelson Division Chief (303) 497-7410 enelson @its.bldrdoc.gov

7 Radio noise can degrade the Radio Noise and Spectrum Occupancy performance of Measurement Research wireless communication Outputs devices. To ensure • Comparison of measured man-made radio noise levels with current models and results reliable from other measurement studies communications, radio systems must • Publication of NTIA report describing the Boulder/Denver area noise measurements, be designed to subsequent data processing and analysis, and comparison of the results with current compensate for models and other measurement studies noise as well as to • Development of techniques for obtaining the time-domain characteristics and protect against observing the maximum levels of impulsive noise events that cause noise interference. measurement system overloads Accurate and reliable Overview Noise Measurement Data measurements of Comparison radio noise provide roper radio communication system design important Prequires, among other considerations, The first major goal of man-made radio noise information for knowledge of the noise and interference research at ITS in FY 2011 was to compare the effective design of environment at the receiving location. While radio noise levels observed during the measure- wireless distinguishing between noise and interference ments taken by ITS in the summer of 2009 to communication is subject to different interpretations, one levels predicted by the current International systems. The interpretation is that interference arises from Telecommunication Union (ITU) man-made radio noise model. The noise measurements were results of ITS noise intentionally radiated signals, whereas noise taken at center frequencies of 112.5, 221.5, measurements arises either from natural sources or from unin- influence design and 401 MHz at two business locations and tentionally radiated signals generated by man- decisions by two residential locations in the Boulder/Denver made sources. Noise can also be either internal private companies area. For each frequency and location, the data or external to the receiving system. and public entities. were collected every 10 minutes as a wideband External, man-made noise was studied ex- complex baseband data record consisting of six tensively in the 1960s and 1970s, culminating million in-phase (I) and quadrature phase (Q) in the development of a man-made noise model data samples in a 1.16 MHz bandwidth. that is still in use today (see Recommendation The measurements used to develop the ITU-R P.372-10). However, there are many ITU model, taken from the mid-1960s to the reasons to suspect that the man-made radio early 1970s, were taken with a measurement noise environment may have changed since the system having a 4 kHz equivalent noise band- 1970s. The introduction of new technologies width. Therefore, to accomplish an accurate such as computers, cellular telephones, and comparison between the results of the current other electronic devices; increases in spectrum measurement study and the ITU model, the crowding; the use of RF overlay technologies; current measured data were filtered in software the aging power distribution infrastructure; and to a 4 kHz equivalent noise bandwidth before processing. improvements in auto ignition systems repre- One of the key advantages of the ITS noise sent some of the changes that are likely to have measurement system is its ability to record had an impact. Furthermore, there is concern wideband I and Q data and thereby permit post that the growing popularity of hybrid electric processing filtering of the data to narrower and plug-in electric vehicles, with their potential bandwidths. After filtering, the data were for generating greater levels of electromagnetic then processed to obtain values of the median interference, may increase levels of man-made antenna noise figure Fam, a standard measure radio noise in the future. Because of all these used to statistically describe noise power lev-

factors, there has been a renewed, worldwide els. Hence, values of Fam provide an excellent interest in measuring, quantifying, and model- means of comparing results from different ing man-made radio noise. man-made radio noise studies. Figure 1 shows

8 Spectrum and Propagation Measurements

35 ITS Measurements 2009 Figure 1 (left). Comparison of Related All 112.5 MHz data ITU Model measured and predicted values Publication: 30 } Hagn Model ITS Measurements 1996−1997

b) of Fam and standard deviation of

0 MASS Measurements 2006 J.A. Wepman and 25 F for business locations. am G.A. Sanders, All 221.5 MHz data 20 } Figure 2 (below). Maximum “Wideband man- 15 power levels of impulsive noise made radio noise measurements in 10 measured at a center frequency (dB above kT

a the VHF and low

F 5 of 112 MHz on the U.S. Depart- ment of Commerce Boulder UHF bands,” NTIA 0 Technical Report 112.5 137.5 209.5 221.5 401 425 Laboratories Campus. Frequency (MHz) TR-11-478, Jul. 2011. a comparison of values of −25 Maximum Power Level of Impulsive Noise VSA Overload Threshold Level Fam and standard deviation −30 of Fam between those com- −35 puted from the measure- −40 ments in this study, previous −45 measurements taken by ITS −50 and MASS Consultants Lim- −55 ited in the United Kingdom, Power (dBm) and those predicted by the −60 ITU and Hagn (another −65 well-known model) models −70 0 25 50 75 100 125 150 175 200 225 for business locations. Note Time (minutes) that values of Fam computed from the measurements in this study, while greater than those predicted of the basic ITS noise measurement system is by the ITU model, were still roughly within one used with low-sensitivity and a VSA span wide standard deviation of those predicted by the ITU enough to encompass the 60 dB bandwidth of model. the fixed RF bandpass filter (9.28 MHz). To best Other Work capture the maximum levels of impulsive noise, A pivotal accomplishment in FY 2011 was the an automated, zero-span, swept measurement completion and publication of a comprehensive system using peak detection was developed. NTIA report describing the ITS noise measure- Use of this type of system allows determination ment system, the recent noise measurements of the maximum levels of impulsive noise that taken by ITS, and the results of the subsequent occur by being able to observe levels continu- data processing and analysis. ously over a much longer time period than with Additional work in FY 2011 included the development of measurement techniques to the VSA-based noise measurement system. characterize the nature of, and to determine Measurements using both systems were com- the maximum levels of high-level impulsive pleted on the U.S. Department of Commerce noise events that cause overloads to the vector Boulder Laboratories Campus during FY 2011. signal analyzer (VSA) used in the noise measure- Figure 2 shows an example of the maximum ment system. A better understanding of the power levels of impulsive noise measured at a For more nature and levels of high-level impulsive noise information center frequency of 112 MHz at this location is needed to help achieve the goal of improving contact: along with the threshold level that would cause the dynamic range of the noise measurement Jeffery A. Wepman system and preventing measurement system a VSA overload to occur. Further measurements (303) 497-3165 overloads. To provide a time-domain character- in the downtown Denver area (a higher noise jwepman ization of the impulsive noise, a modified version level environment) are planned for next year. @its.bldrdoc.gov

9 Accurate information about RSMS Development current spectrum Outputs occupancy is a prerequisite for • Completed a scheduler for the RSMS-4G software, completing the suite spectrum • Completed a four-week-long spectrum survey in Arvada, CO management and • Completed a series of seminars demonstrating how to use the RSMS-4G software optimization, but accurately • Completed measurements to determine the best measurement practices for inclusion characterizing in a spectrum measurement techniques report to be released early next fiscal year spectrum • Completed the “RSMS-5G Programming Guide” outlining coding conventions and occupancy is both architecture for the next generation of RSMS software time-consuming and complex. he Radio Spectrum Measurement Science statistics such as peak use times, channel oc- th The RSMS T(RSMS) 4 generation measurement sys- cupancy and channel usage can be determined measurement tem consists of state-of-the-art tools (vehicle, through post-processing. Using the scheduler, system was software and hardware) for making measure- it is possible to schedule routine calibrations to developed to ments to characterize spectrum occupancy, ensure the system is running properly and that enable accurate, ensure equipment compliance, determine the data being collected can be processed cor- repeatable, electromagnetic compatibility, and analyze rectly once the measurement completes. Several actionable surveys interference problems. The RSMS Develop- seminars were presented to train ITS engineers of radio wave ment Program ensures that the Institute for in the use of the new scheduler and the mea- activity of all types, Telecommunication Sciences (ITS) has the most surement capabilities of the RSMS-4G software. in all bands. advanced software and hardware to perform Spectrum Measurement Best accurate and complete measurements. ITS Practices Development and spectrum measurements provide NTIA with Spectrum Survey critical scientific data to support the development and determination of telecommunication Throughout FY 2011, measurements and policies affecting both the public and private research were conducted to determine the best sectors. To sustain this function, several new measurement techniques to use when mea- capabilities and improvements were added to suring different types of radio signals. These RSMS in FY 2011. Looking to the future, the 5th techniques were later used while performing generation of RSMS measurement software was a spectrum survey. Accurate identification of defined in FY 2011 and development will begin spectrum usage depends significantly on using in FY 2012. the appropriate measurement techniques for the band being surveyed. An NTIA report detail- Scheduler Development and ing these techniques has been prepared and is Completion of the RSMS-4G now proceeding through peer review for release Software in FY 2012. Over the past decade, many different mea- A comprehensive spectrum survey was surement techniques have been developed conducted to explore the nature of spectrum within the RSMS-4G software suite. In FY 2011, usage in the frequency range between 108 the RSMS-4G scheduler was created, completing MHz and 10 GHz in Arvada, CO during the the RSMS-4G software package. The scheduler summer of 2011. Figure 1 shows the RSMS-4G allows researchers to schedule many different vehicle, which serves as a mobile lab, set up to types of measurements to run autonomously conduct these measurements. Two separate over a period of time. This makes it possible to systems were run simultaneously in the RSMS apply the appropriate measurement techniques vehicle, with one system dedicated entirely to for each type of radio signal being measured measuring land-mobile radio (LMR) bands to during a spectrum survey. It also makes it pos- monitor spectrum usage. Some of these bands sible to measure dynamic frequency bands and are currently being investigated as potential others that are of interest to policy makers with candidates for spectrum sharing by government greater fidelity. Dynamic frequency bands need and public sector communication devices. The to be measured multiple times a day, so that use of advanced spectrum sharing technologies

10 Spectrum and Propagation Measurements

Figure 1. RSMS-4 measurement vehicle in Arvada, CO, while performing a spectrum survey.

Figure 2. ITS engineers Chriss Hammerschmidt (left) and Heather Ottke monitoring the spectrum survey while in progress.

Photos by R.J. Hoffman.

to share LMR bands has been proposed as one The next generation of RSMS software, way to more efficiently use the spectrum. The RSMS-5G, has been designed as a collection of second system monitored the rest of the radio tools and measurements that make use of these spectrum from 108 MHz to 10 GHz using many tools rather than a large complex single soft- different measurement techniques. Figure 2 ware package. This will make it possible to rap- shows ITS engineers monitoring the spectrum idly develop measurements as they are needed survey measurement in Arvada, CO. once the core software package is complete. The Next Generation of RSMS RSMS-5G will also be compatible with more Software modern computer systems and multiple operating systems. The need for third party software With the completion of the RSMS-4G soft- has been greatly reduced, so as to extend the ware, it is time to start looking to the future. For more life of the software and reduce cost. During FY In the past, the typical RSMS software has had information 2011, the “RSMS-5G Programming Guide” was approximately a 10 year life cycle; however, the contact: RSMS team has worked to extend the life of the completed. This guide outlines the software ar- Geoff Sanders 4th generation software to 15 years, so as to chitecture, coding conventions, and functional (303) 497-6736 allow overlap between its use in the field and requirements of the RSMS-5G software. Devel- gsanders the development of the next generation. opment of this software will begin in FY 2012. @its.bldrdoc.gov

11 ITS is the principal Federal resource RSMS Operations for technical Outputs assistance in understanding and • Emission measurements of four Navy radar systems to support the U.S. resolving Administration’s position in the International Telecommunication Union’s Working telecommunication Party 1A meeting challenges. Other • Emission measurements of a sub-sampling of existing airborne radio altimeters to Federal agencies jointly develop a measurement approach with the FAA that can be used for future request the emission measurements of radio altimeters assistance of • Follow-up field testing of Unlicensed National Information Infrastructure devices in the RSMS presence of a 5 GHz weather radar measurement expertise and • Technical assistance to the U.S. Department of Defense regarding electromagnetic capabilities to compatibility between L-band radar systems and other services in the same frequency resolve existing band interference • Technical assistance to the Federal Aviation Administration and Federal problems, to plan Communications Commission regarding electromagnetic compatibility between appropriately to Terminal Doppler Weather Radar systems and unlicensed wireless devices operating in prevent the same frequency band interference, and to optimize signal Overview RSMS Operation program (Figure 1), were submitted as U.S. contributions to the ITU Working coverage and he Radio Spectrum Measurement Sci- Party 1A meeting in 2011 to support the U.S. quality. Tence (RSMS) program performs critically needed and time-sensitive radio signal measurements that facilitate Federal Government spectrum allocation decisions and policy making. NTIA Departmental Organization Order 25-7 assigns ITS responsibility for measurements that will guide the effective and efficient use of the spectrum. RSMS program managers coordinate with the NTIA Office of Spectrum Management (OSM) to ensure that identified spectrum research needs are addressed. Through the RSMS Operations program, ITS provides NTIA, other Federal agencies, and the executive branch with radio spectrum data, data analysis, reports, and summaries. RSMS encompasses the following types of measurements: • Spectrum surveys and channel usage • Equipment characteristics and compliance • Interference resolution and electromagnetic compatibility • Signal coverage and quality Navy Radar Emission Measurements International Telecommunications Union (ITU) Recommendation SM.1541 Annex 8 speci- fies the out-of-band emission limits for radar systems internationally and is akin to the United States’ Radar Spectrum Engineering Criteria Figure 1. The RSMS truck collecting emission (RSEC). Emission measurement data of four measurement data from Navy radar systems. Navy radar systems, taken in FY 2011 under the Photo by John E. Carroll.

12 Spectrum and Propagation Measurements

Related Publications J.E. Carroll, F.H. Sanders, R.L. Sole, and G.A. Sanders, “Case Study: investigation of interference into 5 GHz weather radars from unlicensed national information infrastructure devices, Part I,” NTIA Report Figure 2. ITS engineers Frank Sanders (left) and Geoffrey Sanders (no relation) perform field tests TR-11-473, to verify that 5 GHz U-NII devices with newly-developed firmware correctly detect TDWR signals. Nov. 2010. Photo by John E. Carroll. J.E. Carroll, G.A. Administration’s position on changes to Rec- microbursts, and other weather hazards for Sanders, F.H. ommendation SM.1541, which were ultimately improved safety of operations in and around Sanders, and R.L. Sole, “Case Study: adopted. The changes are intended to promote major airports. In 2009–2010, ITS conducted Investigation of more efficient use of the radar spectrum by field measurements to identify the cause of interference into certain classes of radar systems, to which these interference and laboratory tests to understand 5 GHz weather Navy radar systems belong. the interference mechanism and how to im- radars from prove the FCC device certification process to Radio Altimeter Emission unlicensed national prevent interference. Measurements information In FY 2011, the RSMS Operations program The RSMS Operations program measured infrastructure continued to support the FAA and the FCC to emissions from 25 airborne radio altimeters and devices, Part II,” identify solutions to prevent interference to post-analyzed the measurement data to arrive NTIA Report these critical radar systems. As technical subject at a preliminary determination of spectrum us- TR-11-479, matter experts ITS engineers participated in age in the 4200 to 4400 MHz band. Using these Jul. 2011. meetings with the FAA, FCC, OSM, and private preliminary results, ITS engineers created a draft industry representatives. ITS engineers worked measurement approach that can be used for with private industry representatives to field test future radio altimeter emission measurements. (Figure 2) U-NII devices with newly-developed RSMS engineers will be working with the FAA firmware upgrades that better detect TDWR in 2012 to perform a comprehensive study of signals. These tests were performed in the pres- radio altimeter emissions that will be used to ence of an actual TDWR system in Oklahoma determine the spectrum usage of a broad array City, OK, to verify proper operation of the new of radio altimeters, as well as to further refine detection algorithms. ITS engineers also devel- the measurement approach. oped a new set of simulated TDWR waveforms Terminal Doppler Weather for use in the FCC 5 GHz U-NII device certifica- Radar Interference tion process. Both of these efforts will ultimately In early 2009, the Federal Aviation Adminis- reduce occurrences of interference to TDWR For more tration (FAA) became aware of interference to systems from 5 GHz U-NII devices. information their 5 GHz Terminal Doppler Weather Radars Finally, ITS publicly released the first two contact: (TDWR) systems from Unlicensed National In- NTIA reports (of a three part series) detailing John Carroll formation Infrastructure (U-NII) wireless devices the 2009 to 2010 NTIA study of electromag- (303) 497-3367 operating in the same frequency band. TDWRs netic compatibility between TDWR systems and jcarroll@ provide warnings of gust fronts, windshear, 5 GHz U-NII devices. its.bldrdoc.gov

13 The Spectrum Sharing Innovation Spectrum Sharing Innovation Test Bed Test Bed Pilot Pilot Program Program provides an opportunity for Outputs Federal agencies to • Completed and documented Phase I lab measurements on a second and third set of work cooperatively DSA devices with industry, researchers, and • Drafted a Phase II/III field test plan which was reviewed by Federal agencies academia to • Assembled test equipment for field tests and validated proposed measurement objectively examine methods new technologies that can improve management of the Overview spectrum sharing without harmful interference nation’s airwaves. TIA, in coordination with the FCC and to incumbent systems. Dynamic spectrum Nother Federal agencies, established a The program is divided into two phases of access holds out Spectrum Sharing Innovation Test Bed pilot testing. Phase I takes place under controlled the promise to program to examine the feasibility of dynamic conditions at ITS’s lab in Boulder. Testing in- allow users of land spectrum sharing between Federal and non- cludes measurements of typical radio charac- mobile radio to Federal users as a means of improving spectrum teristics such as transmitter emissions, sensor share spectrum efficiency. The program is evaluating the abil- performance, and policy-based radio etiquettes. with each other ity of dynamic spectrum access (DSA) devices Figure 1 shows an ITU standard Head and Torso and with other that use spectrum sensing and/or geolocation Simulator (HATS) being used in the laboratory users in the same techniques to share spectrum with land mobile to create reference recordings for use in tests. or adjacent bands. radio (LMR) systems operating in the 410–420 Figure 2 shows the results of field measure- But is this MHz Federal band. DSA technology allows a ments in a live LMR environment. NTIA’s Office technology ready radio device to evaluate its radio frequency of Spectrum Management will use the lab mea- to ensure the environment using spectrum sensing and/or surement data to construct predictive models of availability and geolocation, to determine which frequencies the interference potential of DSA devices both lack of interference are available for use on a non-interference ba- individually and in the aggregate. In Phases II that is mission sis, and to reconfigure itself to operate on the and III, a set of field tests will be used to validate critical to public identified frequencies. DSA sensor and geolocation performance in live safety users? In FY 2011, program participants were de- LMR environments. layed in delivering their devices for lab testing, Phase I Testing so the program’s emphasis shifted to prepara- At the end of FY 2010, ITS had completed tions for field-testing of the two devices that Phase I lab testing on one device, was in the had completed the Phase I battery of tests. ITS midst of testing a second device, and had just engineers drafted a field test plan to satisfy the received a third device for evaluation. This year, requirements laid out for Phases II and III of the engineers completed testing on the second program charter. The Interdepartment Radio Advisory Committee’s Technical Subcommit- device. An equipment failure hindered this tee (IRAC/TSC) as well as the DSA equipment effort and required that a replacement device providers participating in the test bed vetted be obtained, which in turn necessitated a the test plan. The plan will be announced in a series of regression tests. Testing on the third Federal Register Notice early in FY 2012, which device covered a number of essential tests but will pave the way for field testing. could not be completed. This device required a number of software configuration changes to Program Design permit its operation in the controlled conditions The test bed program assesses the character- stipulated in the test plan. During configuration istics of several DSA devices under both lab and of this device, engineers discovered deficiencies field conditions to determine the maturity of in its communications protocol that brought DSA technology and to inform the rulemaking into question its suitability for further testing. process. The objective is to define the essential The device was subsequently returned to the DSA qualities that must be regulated to permit participant for further analysis.

14 Spectrum and Propagation Measurements

mobile radios (LMR). The tests quantified the effect of DSA emissions on the operation of LMRs at marginal power levels. Analysis of the results indicated that assumptions drawn from TSB-88.1-C, a handbook on LMR systems engineering, could be applied to predict the nature of DSA to LMR interference. Only a simple adjustment that accounts for the differences between DSA and LMR emissions is required. Another test showed how a DSA device loitering in the proximity of an LMR receiver could cause chronic interference with inbound transmissions. Preparation for Phases II and III In FY 2011 ITS engineers, drawing upon a number of exploratory measurements, completed a draft field test plan which covers Phase Figure 1. Recordings of phonetically balanced II and III of the program. The test plan was pre- English speech are captured using a reference sented to Federal agencies for review and com- LMR for later playback in field tests. Photo by ment through the IRAC/TSC review process. This Eric Nelson. was followed by a test bed participant review. Phase II of the test plan provides for the In July, ITS received a fourth DSA device examination of DSA devices’ spectrum sensing for testing. After completing a preliminary capabilities in a live LMR environment with the evaluation of its functionality several software transmitters attenuated to mitigate the poten- maintenance utilities were requested of the tial for interference. After successful comple- participant to permit engineers to configure tion of Phase II, the devices will be permitted the radios for testing. The test bed participant to transmit freely in the test bed environment. is developing a user interface which will support Phase III will expose the DSA devices to a va- this requirement. riety of controlled and uncontrolled conditions In addition, ITS completed a set of tests to and examine their behavior, and document any determine the interference protection criteria instances of harmful interference to incumbent for DSA sharing with typical incumbent land LMR systems.

Figure 2. A spectrogram obtained in a field test shows a collision between a For more DSA device information and incum- contact: bent LMR Eric D. Nelson transmissions. (303) 497-7410 enelson @its.bldrdoc.gov

15 FCC regulations restrict wireless Table Mountain Research Program radio transmissions Outputs in two “radio quiet zones” in the U.S. • Ground constant measurements and modeling Restrictions are • NOAA Weather Radio Receiver performance testing and validation designed to • Antenna characterization and radio propagation studies minimize harmful interference at the • Radar and LADAR research National Radio Astronomy Overview Synthetic aperture LADAR is one of the emerging technologies tested by CRADA partners at Observatory and he Table Mountain Field Site and Radio Table Mountain. Applications include bio-aero- the neighboring Quiet Zone supports fundamental research T sol detection and long-range three dimensional Naval Radio into the nature, interaction, and evaluation holographic imaging. Research of telecommunication devices, systems, and Observatory, both services. In addition to ITS Science and Engi- NOAA Weather Radio (NWR) in West Virginia, neering projects designed to enhance scientific Testing and at Table knowledge, other telecommunications research NWR provides continuous information on the Mountain. ITS is performed at Table Mountain through coop- latest weather conditions directly to the public administers the erative research and development agreements from the National Weather Service (NWS) of- Table Mountain (CRADA) with private industry. CRADAs allow fices. A 1975 White House Policy statement des- site for the DOC private companies to benefit from the unique ignated NWR as the sole Government-operated Boulder resources available at ITS to test and optimize radio system to provide warnings regarding Laboratories. In new and improved products prior to bringing natural disasters and nuclear attack directly into addition to them to market. private homes. As an extension to this policy, coordinating use of in cooperation with the Federal Emergency the site by Federal Free Field Measurements of the Management Agency (FEMA) and the Federal laboratories, ITS Electrical Properties of Soil Communications Commission (FCC), NWS has makes it available ITS engineers have been experimenting with expanded the role of NWR to include “all haz- for commercial and a number of different methods for measuring ards”—natural disasters such as earthquakes or academic research the dielectric properties of soil at the Table avalanches, environmental catastrophes such as and development Mountain site. Numerical simulations for several chemical releases or oil spills, and public safety through different measurement approaches have been emergencies such as AMBER Alerts™ or 911 cooperative created, and prototypes of systems based on telephone outages. agreements. these simulations have been built and tested at the Table Mountain facility (Figure 1). The goal of this program is to identify the technical challenges for making these measurements, and to develop a measurement technique that may be used to map the electrical properties of surface soils at the Table Mountain site. These data can then be used to calibrate other measurement systems, and will help improve propagation modeling and prediction tools for near-Earth radio-wave propagation. Radar and LADAR Research The Table Mountain field site provides a large, open, unobstructed area that is ideal for the study of traditional radar as well as laser based LADAR systems. Researchers use the Table Mountain facility to validate new measure- Figure 1. ITS engineers set up equipment for ment methods, and to test the operation and measuring the dielectric properties of soil. performance of new radar and LADAR systems. Photo by Wayde Allen.

16 Spectrum and Propagation Measurements

Figure 2 (left). View of the Table Mountain site showing the NOAA weather radio antenna tower.

Figure 3 (below) The RF shielded enclosure used for NWR testing at Table Mountain.

Photos by Raian Kaiser

ITS has developed simulated broadcasts and a series of repeatable measurement methods to test the performance of NWR receivers (Figures 2 and 3). NOAA allows receivers that demonstrate they meet the required performance standards to bear the NWR logo, certifying to the public that they are capable of receiving weather and/ or warning information from NWS Forecast Of- fices, Department of Homeland Security offices, and Emergency Operation Centers. Individual NWR receiver manufacturers enter into CRADAs with ITS in order to have units tested, problems uncovered and improvements made to receiver models before applying to NOAA to use the NWR logo. The compiled results of numerous tests also help NOAA determine the possible cause of receiver malfunctions reported by the public when units do not respond during a weather event or other broadcast emergency. FAA Certificate of Authorization applications FY 2011 CRADA Partners for small unmanned aircraft,” Infotech@Aero- • Areté Associates space 2011, St. Louis, MO, Mar. 2011 • Lockheed Martin/Coherent Technologies • J. Elston, B. Argrow, A. Houston, and E. Frew, • First RF Corporation “Design and validation of a system for targeted • University of Colorado, AUGNet observations of pre-tornadic supercells using unmanned aircraft,” IEEE/RSJ International CRADA Partner Publications Conference on Intelligent Robots and Systems, • B. Argrow, E. Frew, J. Elston, M. Stachura, J. Taipei, Taiwan, pp. 101-106, Oct. 2010 For more Roadman, A. Houston, and J. Lahowetz, “The • B. Pearre and T.X. Brown, “Model-free trajec- information Tempest UAS: The VORTEX2 supercell thun- tory optimization for wireless data ferries contact: derstorm penetrator,” Infotech@Aerospace among multiple sources,” IEEE GLOBECOM J. Wayde Allen 2011, St. Louis, MO, Mar. 2011 2010 Workshop on Wireless Networking for (303) 497-5871 • J. Elston, M. Stachura, B. Argrow, E. Frew, and Unmanned Aerial Vehicles, Miami, FL, Dec. wallen C. Dixon, “Guidelines and best practices for 2010. @its.bldrdoc.gov

17 In a joint research Below: U.S. Commerce Secretary John Bryson (left) visited ITS’ public safety labs. Jeff Bratcher effort between ITS (second left) demonstrated to Secretary Bryson how ITS studies the effects of background noise on and NIST/OLES, voice intelligibility. Bryson met the PSCR program firefighters Ken Link (third left) is building and and Paul Roberts (right) who testing a 700 MHz were participating in video acu- Public Safety ity experiments for public safety. Broadband Roberts and Link described how Demonstration ITS research relates to their Network to provide own real-world fire fighting manufacturers and experiences. Photo by Will von first responders a Dauster. location for early deployment of their systems in a multi-vendor, Left: ITS staff maintain Long-Term neutral, host Evolution (LTE) antenna panel environment. The connections at the Table Moun- network comprises tain Field Site, which houses a three stationary stationary eNodeB near the tower. eNodeB base Photo by Ken Tilley. stations, and one mobile eNodeB station housed in a truck. This configuration allows stakeholders to perform comprehensive system and node- level tests, including in-depth and advanced performance testing and multi- user, loaded network stress testing.

Above right: The Green Mountain Mesa Field Site houses the network’s second stationary eNodeB in the structure below the LTE tower. Right: Dr. Rob Stafford of ITS (center, facing) shows the Broadband Demonstration Network to participants during one of two stakeholder meetings hosted by PSCR in FY 2011. The third stationary eNodeB station (left of center, beige with three black bolts) is housed in this ITS lab. Photo by Ken Tilley.

18 Telecommunications and Information Technology Planning

Telecommunications and Information Technology Planning

he Telecommunications and Information Technology Planning Division is focused on research, Tdevelopment, and testing efforts from the perspective of the system or network level. Projects include development, testing, and evaluation of existing, new, and proposed telecommunications and information technology systems with a focus on improving efficiency, interoperability, performance, and reliability. This work, commonly referred to as systems engineering, is performed for both wireline and wireless applications. The division conducts all phases of strategic and tactical planning, as well as problem solving and actual engineering implementation. ITS engineers identify users’ functional requirements and translate them into technical specifications. In the process, telecommunication system designs, network services, access technologies, and information technologies are all analyzed. The work within the Public Safety Communications Research (PSCR) program, a joint effort between ITS and the NIST Office of Law Enforcement Standards (NIST/OLES), continues to focus on public safety interoperable communications. The program performs research, development, testing, and evaluation to foster nationwide public safety communications interoperability. Below is a summary of the significant project areas that researchers in the Telecommunications and IT Planning Division worked on during FY 2011. Details pertaining to each project are described in separate sections on the following pages.

Multimedia Quality Research efforts aimed at facilitating communications interoperability and information sharing within The Institute characterizes and analyzes the the public safety community. The sponsors of fundamental aspects of multimedia quality as- the program’s research include the Department sessment. A primary goal of this research is to of Homeland Security and the Department of develop an algorithmic system to objectively Justice. PSCR projects are planned and per- assess multimedia quality by combining audio formed with coordination among local, State, quality, video quality, and audiovisual synchro- tribal, and Federal practitioners. Technical nization information. thrusts within the program include: • Project 25 Compliance Assessment Program Public Safety Communications • Project 25 Standards Development Research • Public Safety Audio Quality The PSCR program (www.pscr.gov) is one of • Public Safety Broadband Demonstration the largest sponsored programs at the Institute. Network The program conducts broad-based technical • Public Safety Broadband Research

For more information contact: Jeffrey Bratcher Division Chief (303) 497-4610 jbratcher @its.bldrdoc.gov

19 The Multimedia Research Project Multimedia Research explores audio Outputs quality and video quality • Technical papers interactions. • Subjective test best practices Technical papers • Technical content for standards describe the techniques, experiments and Overview A study documenting the development of underlying he Audio Quality and Video Quality Proj- an audiovisual model (an equation used to algorithms, Tects at ITS study audio quality and video calculate audiovisual quality) appeared in the transferring the quality individually. This dichotomy is often IEEE Signal Processing Magazine in November technology and the advantageous for researching compression and 2011. The equation uses individually measured tools to other delivery methods but does not represent how audio and video quality to predict audiovisual researchers in most people consume movies, television or In- quality and is surprisingly simple—a simple mul- government, ternet video. The Multimedia Project builds on tiplication of audio quality times video quality academia and the subjective and objective quality assessment provides a fair estimate of audiovisual quality. private industry. methods developed by the Audio Quality and This equation can help: The objective Video Quality projects. • Telecommunications service providers to quality apportion audio and video bandwidth measurements Audio Quality × Video Quality intelligently. produced by ITS = Audiovisual Quality • Equipment manufacturers build tools to research help Multimedia subjective tests methodically ask predict audiovisual quality from separate mea- multimedia many people their opinion of many multimedia sures of audio quality and video quality. businesses make clips. Between 2006 and 2010, the Multimedia It can also inform the design of forthcoming informed design Project conducted a series of subjective tests audiovisual subjective tests and objective quality decisions about that looked at the impact of audio and video on measurement tools. trade-offs among people’s opinion of audiovisual quality. Each test An International Study: quality, asked people their opinion of audio samples, of Improving Audiovisual video samples, and of audiovisual samples. Labs compression and Subjective Tests bandwidth. around the world conducted similar tests. Normally, subjective tests are conducted in a highly controlled lab environment (see Audio Visual Laboratories, page 84) according to International Stan- dards (e.g., ITU-T P.910, ITU-R BT.500). The controlled environment resembles the places where most television and movies used to be watched—a living room or home theater.

Figure 1 (above). ITS test chamber set up to look like a living room. The curtains were opened to allow sunshine into the room. Figure 2 (right). This side of the room gave people the option of putting a mobile device on the table. People had the choice of stand- ing, sitting or pacing, as they would in the real world. Photos by Andrew Catellier.

20 Telecommunications and Information Technology Planning

greatest effect on the experimental results. Other factors, such as the native language of the country in which the experiment took place, lighting in the experiment environment, and background noise, had minimal impacts. Further analysis and a publication describing this experiment will occur next year. The results of this experiment will influence new ITU Recommendations for subjective testing and will be submitted to a journal for publication.

Figure 3. Taking a subjective test in the cafeteria. Back- Subjective Tests with ground noise included conversations among patrons, Mobile Devices music, and food preparation. Photo by William Ingram. Because the number and availability of Internet-connected mobile Now, thanks to ubiquitous Internet access, devices is swelling, it is becoming increasingly smartphones, tablets, and laptops, video is likely that any given person will view multimedia available nearly anywhere. These devices and content on a mobile device. Additionally, in de- services raise unique questions about delivered veloping countries, Internet-connected mobile multimedia quality and Quality of Experience, devices are the only way people can view multi- questions that cannot be answered in tradi- media. The existence of these devices makes the tional laboratory environments. New subjective task of ensuring high-quality content delivery testing methods that allow for flexible testing much more complicated. environments must be developed. For example, someone could use a set top Six laboratories from four countries con- box to watch a previously broadcast football ducted a study of subjective test environments. game on a large TV in a living room. Another Most experiment variables were constant at person could stream a live broadcast of the each lab, except for the experiment’s environ- football game to a laptop while working in a ment. Some labs conducted the experiment in coffee shop. A commuter using a video-on- controlled, traditional lab environments; others demand service could use a tablet to watch the conducted the experiment in a cafeteria (Fig- latest popular sitcom. Students abroad could ure 3), in a hallway, or on a patio. download a weather forecast using a smart- The results delivered by each lab were sta- phone. How is delivered quality measured in tistically equal. As it turns out, the number of these situations? subjects that participated at each lab had the To answer this question, ITS conducted subjective tests using HDTV videos. The subjects were shown the same audio and video on six devices: two smartphones, a tablet (Figure 4), two laptops, and a broadcast-quality television and speakers. Like the aforementioned international study, this experiment was conducted in two different environments. One was a traditional lab envi- For more ronment and the other was a simulated living information room (Figures 1 and 2). The quality ratings contact: obtained in the lab and in the living room were Arthur A. Webster Figure 4. Taking a subjective test in the living statistically identical. (303) 497-3567 room, while relaxing in a comfortable chair. Further analysis and a publication about this awebster Photo by Andrew Catellier. experiment will occur next year. @ its.bldrdoc.gov

21 The P25 Compliance Project 25 Compliance Assessment Assessment Program Program impacts billions of dollars in Outputs purchases of public • Development of technical materials for DHS P25 CAP Governing Board safety equipment by providing a • Grant guidance language for Federal P25 equipment grant programs mechanism to • Laboratory assessment program management and subject matter expertise ensure that • Compliance assessment related P25 standards purchased equipment conforms to Overview P25 Compliance Assessment Program (CAP) to test equipment for standards compliance. interoperability istorically, public safety agencies have standards. By Hpurchased and used equipment made Program Structure supporting the by different manufacturers with inconsistent The P25 CAP is a voluntary program that migration from manufacturing practices and using different allows P25 equipment suppliers to formally proprietary and spectra. As a result of these inconsistencies, the demonstrate their products’ compliance with stove-piped equipment could not interoperate, preventing a select group of requirements within the P25 communications many public safety agencies from communicat- suite of standards. The purpose of the program systems to open, ing when lives were in danger. Public safety standards-based is to provide emergency response agencies with organizations and the communications industry infrastructure, the evidence that their communications equipment partnered through Project 25 (P25) to eliminate P25 CAP ensures meets P25 standards for performance, confor- these issues by developing standards for easy that emergency mance, and interoperability. Rather than relying interoperability of radios and other components response on a large centralized test facility, the program regardless of manufacturer. The goal of P25 is to technologies recognizes independent laboratories authorized specify formal standards for interfaces between effectively meet to conduct testing. It is an outstanding example the various components of a land mobile radio the needs of of Government making a minimal investment (LMR) system, commonly used by emergency practitioners in that catalyzes industry and the community it the field. responders. serves to develop a solution that will affect bil- After years of effort, industry was successfully lions of dollars in purchases. incorporating standards into much of the radio ITS supports NIST/OLES and DHS OIC in car- and communications equipment used by public rying out the rigorous and objective assessment safety. However, preliminary test data indicated process through which test laboratories dem- that some radios sold under the P25 label did onstrate their competence, promoting the user not meet all of the standards’ requirements. community’s confidence in, and acceptance of, The problem was the lack of a reliable method test results from these recognized laboratories. to verify equipment compliance with P25 stan- Eight laboratories were recognized under this dards. “Testing was something that, for a long program as of May 2009, and all equipment time, public safety assumed occurred, but then suppliers that participate in the P25 CAP must they realized that their toasters were tested to use these recognized laboratories to conduct a higher degree than their radio systems,” says performance, conformance, and interoperability Dereck Orr, National Institute of Standards and tests. The P25 equipment suppliers then release Technology/Office of Law Enforcement Stan- summary test reports from these recognized dards (NIST/OLES) Communications Program labs along with declarations of compliance. Manager. This documentation increases the public’s con- In 2008, ITS, NIST/OLES and the Department fidence in the performance, conformance, and of Homeland Security’s Office of Interoperability interoperability of P25 equipment. Further, the and Compatibility (DHS OIC) worked together declaration of compliance related documents to build an independent coalition of public developed by program participants provide use- safety users and communications equipment ful technical information about the equipment. manufacturers to address this issue. This led to The P25 CAP is a partnership among ITS, DHS the creation of the congressionally-mandated OIC, NIST/OLES, industry, and the public safety

22 Telecommunications and Information Technology Planning

community. It provides a forum where perfor- Responder Knowledge Base (www.rkb.us) Web mance, conformance, and interoperability is- site in January 2010, continue to increase in sues that emerge as the technology and the user number. Currently, P25 equipment from thir- needs evolve can be recognized and resolved teen manufacturers is represented. before product launch and deployment. ITS ITS continues to work within the standards supports this process by leading the develop- development process of the Telecommunica- ment of Compliance Assessment Bulletins and tions Industry Association (TIA) to ensure timely updating them as program needs continuously release of standards that directly impact the P25 adapt to changing user requirements. CAP, particularly test standards for the Common Results Air Interface and the Inter-RF Sub-System Inter- face. Additionally, ITS is working independently The P25 CAP is providing more than 60,000 of TIA to develop conformance tests appropri- emergency response agencies nationwide ate for compliance assessment for inclusion in with a consistent and reliable indicator of P25 the P25 CAP. product compliance. It also provides a means of verifying that billions of Federal grant dollars ITS assisted in developing Federal grant guid- and Federal procurements of LMR systems are ance language for DHS that affects how Federal being invested in standardized solutions and grant money is used by state and local public equipment that promotes interoperability. safety in the purchase of communications The P25 CAP achieved a number of important equipment. milestones in FY 2011, including the release of a The P25 CAP was selected for a US Depart- number of critical requirements documents, all ment of Commerce Silver Medal, the second drafted by ITS. highest achievement in the department, for its Supplier’s Declarations of Compliance and leadership in ensuring public safety communi- Summary Test Reports, first posted to the cations interoperability.

For more information contact: Andrew P. Thiessen (303) 497-4427 Public safety and industry have partnered through P25 on developing standards that allow radio athiessen systems to interoperate regardless of manufacturer. @its.bldrdoc.gov

23 ITS involvement in P25 standards Project 25 Standards Development development Outputs directly supports NTIA’s objectives • Leadership roles and formal participation to promote public safety interests in for developing and achieving P25 goals influencing • Technical proposals to accelerate the development of P25 standards satisfying public national and safety requirements international • User outreach to increase public safety practitioner involvement in the P25 process standards and and the adoption of P25 standards policies to support the full and fair Overview near-term completion, including two of par- competitiveness of ticular importance: the P25 Inter-RF Subsystem the U.S. he overall goal of Project 25 (P25) is to Interface (ISSI) and the P25 Common Air Inter- information and Tenable and promote the development and face (CAI). The ISSI and the CAI are the most technology sectors use of interoperable land mobile radio (LMR) important P25 interfaces because they enable and for enhancing equipment and systems that cost-effectively multi-agency interoperability using multi-man- scientific meet the complex and evolving mission-critical ufacturer P25 radios and P25 infrastructures, knowledge and radio communication needs of the public safety even across large geographic areas including providing community. Project 25 was established in 1989 different public safety jurisdictions. information to by governmental entities and the Association stakeholders to of Public-Safety Communications Officials – ITS Involvement support economic International (APCO) for the primary purpose ITS began to advance the development of P25 growth and of realizing the benefits of digital narrowband requirements and standards shortly after P25 improve LMR technologies for public safety practitioners was established. Under the sponsorship of NIST/ innovation, and other users. To accomplish this vital goal, OLES, support continues for the accelerated technology, and public safety, government, and manufacturer development of P25 standards to meet increas- public safety. representatives participating in the P25 process ing needs for functionally enhanced, compliant develop, as a public-private partnership, vol- equipment and systems, and to satisfy Congres- untary consensus standards with the support sional mandates. ITS’s P25 standards develop- of the American National Standards Institute ment support efforts are also an integral part (ANSI)-accredited Telecommunications Industry of the Public Safety Communications Research Association (TIA). (PSCR) program, a joint effort of ITS and NIST/ APCO Project 25 is unique in that it is an OLES. During FY 2011, ITS provided technical open, user-driven standardization process, with and organizational representation for the spon- technical and operational requirements estab- sor, directly assisting the approval of new and lished through stakeholder participation. TIA revised P25 requirements and standards in sev- published standards set the basis by which: eral critical areas, including the ISSI and CAI. ITS • Manufacturers develop, implement, and offer also supported related areas of emphasis, such P25 equipment and systems. as public safety audio quality research and the • Recognized laboratories conduct P25 compli- P25 Compliance Assessment Program. ance testing. • Users specify, procure, and operate P25 radios Next Generation P25 Wireline and communications infrastructure. Interface Standards The deployment of P25 equipment and ITS technical efforts during this and prior systems continues to grow, with broad adop- fiscal years strongly supported the acceler- tion within the more than 60,000 public safety ated development and approval of new and organizations in the U.S. and by public safety revised P25 standards for the next generation organizations in over 54 countries. (“Phase 2”) P25 wireline interface standards. Recent Congressional legislative and related In FY 2011, ITS focused on advancing the ISSI, actions recognized P25 standardization as the Data Network Host Interface, and the Tele- the preferred solution for narrowband LMR phone Interconnect Interface. As a result, TIA public safety users. Congress identified several expects to publish significantly revised versions key P25-defined open interfaces as critical for of documents describing and defining these

24 Telecommunications and Information Technology Planning

P25/TIA-102 LMR System Configuration P25/TIA-102 Involving the ISSI LMR Service Conventional Complexity Level Trunking 1 2 3 Voice TIA-102.BACA-A TIA-102.BACE TIA-102.BACE (to be specified) Mobility Management TIA-102.BACA-A (not applicable) TIA-102.BACE (to be specified) RFSS Capability Polling TIA-102.BACA-A-2 (not applicable) TIA-102.BACA-A-2 (to be specified) Supplementary Services TIA-102.BACD TIA-102.BACE TIA-102.BACD (to be specified) TIA-102.BACF Packet Data (to be specified) (to be specified) (to be specified) TIA-102.BACA-A-1 Support for Half-Rate Vocoder (to be specified) (to be specified) (to be specified) (to be specified) Project 25/TIA-102 Inter-RF Subsystem Interface (ISSI) protocol communications standards. three P25 interfaces in the near future. ITS remains extremely challenging because of di- also originated numerous technical and edito- verse and evolving user communication needs, rial proposals to advance the development of funding and budgetary constraints, extended a draft telecommunications systems bulletin equipment lifecycles, regulatory changes, and (TSB). When completed TSB-102-B, will provide rapid technological innovation. a critically needed overview of the LMR systems, Leadership and Participation services, and interfaces currently supported by the TIA‑102 series of documents. The TIA-102 ITS leadership in the P25 UNS drove the documentation suite is being developed taking development and approval of an updated P25 into account user needs specified in the P25 SoR in April 2011 to satisfy current user re- Statement of Requirements (P25 SoR). quirements on a timely basis. Continuing into FY 2011, an ITS staff member acted as Editor P25 User Requirements of the P25 SoR, a role ITS staff has performed ITS technical efforts strongly contributed to since 2005 at the request of the P25 Steering accelerated development and approval of new Committee. and revised P25 user requirements by the P25 Formal participation in the P25 process con- User Needs Subcommittee (P25 UNS). Since the tinued throughout FY 2011, with the submission publication of the previous P25 SoR in March of numerous letter ballot comments enabling 2010, technical contributions originated by ITS standards to be approved consistent with ITS enabled the following new and revised P25 user and sponsor objectives. Accelerated comple- requirements to be approved: tion of key P25 standards continued in 2011, • Addition of new requirements for the P25 including the publication of over 20 standards Console Subsystem Interface (CSSI) associated with the CAI, ISSI, and other P25 • Clarification of requirements for the P25 Fixed interfaces. ITS staff continues to conduct impor- Station Subsystem Interface (FSSI) tant outreach activities; for example, enhancing • Clarification of requirements for P25 conven- the P25 Document & Standards Reference (P25 tional and trunked systems DSR) as part of the PSCR program (http://www. • Clarification and extension of voice encryption pscr.gov/outreach/p25dsr/p25dsr.php). requirements In FY 2012, ITS will continue to support For more In FY 2011, ITS continued to increase its accelerated development of key Project 25 information technical support of P25 UNS activities to en- requirements and standards to further realize contact: able the timely realization of P25 user require- interoperable narrowband LMR equipment and Randall S. ments that best serve the overall interests of the systems that satisfy the mission-critical commu- Bloomfield public safety LMR community—an effort that nication needs of the public safety community. (303) 497-5489 rbloomfield @its.bldrdoc.gov

25 Improving spectral efficiency within Public Safety Audio Quality public safety Outputs spectrum depends largely on • Technical reports describing experimental conduct and results increased reliance • Contributions to standards bodies regarding measurement methods for public safety on digital rather audio quality than analog radio technology. Digital Overview information on radio usage, operational environment, and common practices of public radio systems offer ublic safety practitioners work in some safety personnel. Typically, these field studies a number of other of the harshest environments around. P will involve two types of recordings. The first advantages in When they are in those environments, their life is recordings of overall operation that help addition to depends on their ability to communicate with increase understanding and comprehension improved spectral their coworkers and their commanders. It is es- of public safety operational requirements. The efficiency. But for sential that public safety practitioners be able to second type of recording is a high-quality digital public safety call for help, to warn others, to communicate recording of a specific environmental noise that practitioners, when their lives are in danger. However, some can be shared with the community and also intelligibility—the background noises encountered in the public used in laboratory experiments. degree to which safety environment, such as sirens, chainsaws speech can be and personal alert safety systems (PASS), can Laboratory Research understood—is the interfere with those essential communications. The high-quality digital recordings are used highest priority in Sometimes this interference is so severe that it to reproduce real-life sound levels inside a communications. can prevent a practitioner and the person talk- sound attenuated chamber which contains an Public Safety ing with him or her from understanding each ITU-Standard Head and Torso Simulator (HATS) Audio Quality other at the most critical moments. (Figure 1). The HATS has a calibrated speaker research To understand how background noise af- representing the mouth and a calibrated characterizes the fects voice communications and to determine microphone representing each ear. It can be factors that what technology improvements are needed used to simulate a conversation in any noise influence to overcome any background noise issues, ITS intelligibility of and its program sponsors (NIST/OLES and DHS digital radio OIC) have worked with practitioners to develop communications. and implement tests that measure how digital This research radios operate in the presence of loud back- provides digital ground noise. equipment The Public Safety Audio Quality project takes manufacturers and an innovative approach to addressing the needs standards bodies of the public safety community. Working directly important with practitioner agencies, the project conducts information about both field and laboratory studies to increase the how to design awareness of public safety requirements, con- increased duct experiments that reflect the real environ- intelligibility into ment in which public safety must operate, and digital radio quantify potential communications technology systems. issues and identify solutions for those issues. Field Studies The field studies conducted by the project are essential to understand the environments in which public safety practitioners must operate. To date, field measurements and recordings have been made in a variety of public safety Figure 1. An ITU standard Head and Torso vehicles and at several fire scenes to provide Simulator (HATS) outfitted with a firefighter’s information specific to noises encountered mask and set up to talk into a radio. Photo by by the fire service. These field studies provide Ken Tilley.

26 Telecommunications and Information Technology Planning

environment for which a recording exists. Us- • The use of different PASS alarms had no ob- ing a pair of these chambers containing HATS servable impact on intelligibility. enables both halves of a conversation to be • Using a mask with an internal microphone simulated and recorded for later analysis or improved intelligibility over using a mask with playback to a subjective listener panel. a voice port. In a previous subjective experiment, a variety Overall, in the past three years, excellent of fire-specific noises were mixed with audio progress has been made to improve intelligibility to perform an intelligibility test. The noises in- in high-background noise environments. With cluded such sounds as a chainsaw, a fire-hose continued effort on the part of industry and fog nozzle, a low air alarm from breathing public safety, there are promises of even more apparatus, and a PASS alarm. The experiment improvements. This will result in better commu- compared the intelligibility of digital and analog nication for public safety practitioners, improv- radio communication systems in the presence ing their safety and making them more effective. of such noises. Results were published in an 1.0 NTIA Report1 and companion recommenda- 0.9 2008 tions published by the International Association 0.8 2011 of Fire Chiefs.2 0.7

Audio Performance Working 0.6 Group 0.5 Based on that test, the Project 25 standards 0.4 committee created the Audio Performance 0.3 Intelligibility Score Working Group (APWG) to further quantify 0.2 these issues. Working with APWG, industry 0.1 and state and local public safety agencies, ITS 0.0 completed another round of testing in FY 2011. 25kHz Analog P25 Full Rate Some of the observations made based on the System test results are listed below: Figure 2. This chart shows a comparison of • Changes to best practices and technical similar systems’ intelligibility scores in the 2008 changes to the vocoder both improved the and 2011 tests for the PASS alarm background intelligibility of speech. This was especially noise. The analog FM system showed slightly notable in the improvement to intelligibility in improved results and the Project 25 (Digital) the presence of PASS alarm noise for the P25 system showed a marked improvement in system (Figure 2). intelligibility. • There are some conditions where analog radios Future Work still have higher intelligibility than P25 systems. • For all conditions the P25 Full Rate and P25 In FY 2012 the project will finish publish- Half Rate showed no significant differences in ing results of recent testing through the TIA performance. standards committees and begin to study the • The test revealed that for some radio channel impact that emerging broadband wireless net- degradations, P25 systems have a higher intel- work technologies will have on public safety ligibility level than analog systems. voice communication.

1. D. Atkinson and A. Catellier, “Intelligibility For more of selected radio systems in the presence of information fireground noise: Test plan and results,” NTIA contact: Technical Report TR-08-453, June 2008. Jeff Bratcher 2. IAFC Digital Problem working Group, Interim (303) 497-4610 Report and Recommendations: Fireground noise and Digital Radio Transmissions, International jbratcher Association of Fire Chiefs, May, 2008. @its.bldrdoc.gov

27 The public safety community, along Public Safety Broadband with the U.S. Demonstration Network Administration,* has come together Outputs to support the • Standards development contributions to 3rd Generation Partnership Project (3GPP) creation of a single nationwide • Technical contributions to public safety community regarding lessons learned broadband • Technical contributions to the FCC Emergency Response Interoperability Center (ERIC) network for public and policy makers within the Executive Branch safety, eschewing the fractured Overview made the choice for 3GPP’s Long Term Evolu- tion (LTE) as the favored technology standard. approach found in tove-piped proprietary systems and non- The FCC in its Waiver Order1 today’s land mobile contiguous spectrum assignments have also mandated LTE S as the technology to be used in the public safety radio systems. long impeded effective cross agency/jurisdiction broadband spectrum assignment. Traditionally, LMR public safety land mobile radio (LMR) com- Since that time, public safety has worked to networks have munications. To avoid similar issues with new develop requirements to help inform its efforts been built by broadband technology, Congress made spec- to build a nationwide network. PSCR staff chair individual localities trum in the newly cleared 700 MHz frequency the National Public Safety Telecommunication or on a statewide band available to public safety for a unified na- Council’s (NPSTC) Broadband Working Group basis. Deploying tionwide public safety broadband system. The that developed the NPSTC Public Safety Broad- new cellular Federal Communications Commission (FCC) and band Statement of Requirements in 2007. Task technologies public safety leadership are working to develop Groups under the Broadband Working Group nationwide will be baseline requirements for interoperability on that are currently working to update the 2007 more complex and this system. The Public Safety Communications requirements in a piece-meal fashion include: require an Research (PSCR) program, a joint effort of the • Local Control Task Group—working to define unprecedented National Institute of Standards and Technology what local and state agencies will need to level of Office of Law Enforcement Standards (NIST/ control in a nationwide broadband network in coordination. The OLES) and ITS, leads this effort, tailoring it to Public Safety order to meet their needs the unique operational and technical require- Broadband • Priority/Quality of Service Task Group—work- ments specific to broadband communications Demonstration ing to define public safety’s default and for public safety. Network is an dynamic priority and quality of service require- The PSCR Broadband Demonstration Net- independent, ments for LTE to ensure a consistent user work, established in FY 2010, facilitates acceler- vendor-neutral expectation nationwide ated development of standards for emerging venue where public • Multimedia Emergency Services (MMES)— fourth-generation (4G) equipment. The Demon- safety agencies can capitalizing on work in the E-911 arena to stration Network activities will support technical test equipment and develop requirements to extend E-911 capa- contributions to the 3rd Generation Partnership identify bilities to support public safety’s needs Project (3GPP, a collaboration among six tele- interoperability • Voice Task Group—working to define public communications standards bodies to produce issues prior to safety’s mission-critical voice requirements, globally applicable cellular system specifica- building or altering both within the nationwide broadband net- tions), the FCC Emergency Response Interoper- their networks. work as well as between the broadband net- ability Center (ERIC, formed to specifically to work and existing land mobile radio systems address the needs of the 700 MHz public safety • Security Task Group—working to define public broadband wireless network), and other appli- safety’s security requirements in the context of cable standards organizations. a broadband network Public Safety Broadband PSCR staff leverage the public safety commu- Standards and Requirements nity’s requirements work to advance 3GPP LTE standards to meet public safety’s needs. Cur- Public safety and the FCC realized the need rent efforts include working to extend the 3GPP to identify a 4G wireless network standard to * http://ntia.doc.gov/files/ Multimedia Emergency Services efforts based ntia/publications/ntia_pub- facilitate roaming and nationwide interoper- lic_safety_network_com- ability. In 2009, public safety, through nearly all 1. http://fjallfoss.fcc.gov/ecfs/document/ ments_06102011.pdf of its representative organizations, collectively view.action?id=7020505752

28 Telecommunications and Information Technology Planning

on the NPSTC MMES Task Group deliverables as well as working to create a direct mode capability based on NPSTC Voice Task Group deliverables. In addition to participating in 3GPP and other standards development bodies as public safety requirements dictate, PSCR staff are members of the Alliance for Telecommunications Industry Solutions (ATIS) International Mobile Subscriber Identity (IMSI) Oversight Council (IOC), which is responsible for allocation of the U.S. Public Land Mobile Network Identifiers (PLMN ID) to quali- fied applicants. PSCR staff successfully modified the ATIS IOC Guidelines to allow a Public Safety broadband licensee to apply for a single PLMN ID for use in the nationwide network. Goals of the Demonstration Network National telecommunications companies Public Safety Broadband Demonstration Net- maintain sophisticated test networks and work base station at the Green Mountain Mesa dedicated laboratories to ensure that selected site. Photo by Ken Tilley. equipment meets their specifications and to identify interoperability issues prior to building • Assess the defined open interfaces associated their networks or adding new features, hard- with LTE that will ensure interoperability for ware, or software. The Public Safety Broadband the public safety broadband system. Demonstration Network was established at the • Demonstrate broadband air-interface and U.S. Department of Commerce Boulder Labo- core network capabilities to provide proof of ratories to provide an equivalent Government concepts, improve quality of future systems, lab facility in the U.S. where the fragmented, and create new technology and requirement resource-constrained community of public benchmarks. safety agencies could test and demonstrate • Evaluate broadcast capabilities for wide-area public safety 700 MHz broadband networks simultaneous data delivery. and applications. This over-the-air broadband demonstration network and laboratory, operat- • Assess interoperability concepts with existing ing in the public safety broadband spectrum, LMR, cellular, and broadband technology, le- leverages the expertise of the PSCR staff and the veraging several past PSCR projects. unique assets of the Boulder Laboratories—spe- • Explore roaming functionality with LTE and cifically, the Table Mountain Radio Test Site and non-LTE systems, including how quality of the Green Mountain Mesa site. service, billing, priority, preemption, and ap- The Demonstration Network is made avail- plications work when roaming. able through cooperative research and develop- • Validate key public safety functionalities and requirements, and gather public-safety ment agreements (CRADA) for manufacturers For more specific information to influence the LTE stan- and carriers to test the deployment of 700 MHz information systems in a multi-vendor environment. It serves dards process. contact: as an educational site for public safety by allow- In FY 2012, the Public Safety Broadband Jeffrey Bratcher ing interested agencies to observe these systems Demonstration Network project will continue to Division Chief and execute public-safety specific test cases that conduct studies of LTE technology to drive the (303) 497-4610 are unique to their operational environment. development of the nationwide, interoperable jbratcher The Demonstration Network’s goals are to: Public Safety Broadband Network. @its.bldrdoc.gov

29 Public safety broadband users Public Safety Broadband Research have unique needs Outputs compared to users of civilian cellular • Investigations into MIMO mechanisms networks. Signal • Software-defined radio test instrument technologies degradation that is a nuisance to a civilian user may be Overview that are transmitted at the same frequency life-threatening in lthough spectral efficiency (i.e., the but from different antennas. Under good SNR a public safety Anumber of bits per second per hertz) is conditions, the receiver can take advantage of emergency. The important to any high-speed wireless data sys- knowledge of the two slightly different radio most promising tem, public safety broadband users face some paths to separate the two signal components technology to unique problems compared to those encoun- from the aggregate signal received. assure public safety tered in similar civilian cellular networks. Since Investigations of MIMO broadband the business world optimizes its networks to Mechanisms transmissions are cover the maximum number of paying custom- Almost all LTE systems in the U.S. operate both robust and ers, capacity constraints tend to naturally assure in the 700 MHz band and use cross polarized efficient is Long a fairly strong signal for the majority of users. antennas to achieve the radio path differences Term Evolution The public safety network, by contrast, must (LTE) using often emphasize coverage instead of capacity, required for MIMO. Propagation effects on multiple input, since there are no billable customers but inci- these signals due to ground based objects has multiple output dents may happen in areas where population not been extensively studied and consequently (MIMO) density is low (e.g., forest fires). This means that network designers must use very conserva- techniques. The the public safety broadband user may frequently tive assumptions in current LTE networks. The Public Safety encounter conditions of low signal to noise Public Safety Broadband Research project is Broadband ratio (SNR), but his need for maximum data working to fill this knowledge gap using current Research program throughput on the network has not diminished propagation models combined with a measure- at ITS explores even though signal conditions are suboptimal. ment campaign conducted in the laboratory as ways to optimize The Public Safety Broadband Research project well as in the field. For the laboratory work, a these technologies. seeks ways to assure highly efficient data trans- MIMO-capable signal generator is available, but In the process, the fer to public safety broadband users in subopti- field studies require a test signal of significant program is mal radio conditions. Currently, the broadband strength. All current LTE networks provide a test developing new technology of greatest interest to public safety is signal embedded in their LTE transmissions, and tools for active Long Term Evolution (LTE) and, arguably, one of this is being used for the current measurement. network testing. the strongest determinants of spectral efficiency The LTE signal is very complicated, as the While the needs of in LTE is the use of multiple input, multiple schematic in Figure 1 shows. For public safety the public safety output (MIMO) techniques to carry more than use, the signal encompasses 300 subcarriers of community are one information stream over the same spectral 15 KHz bandwidth that change 14,000 times most urgent, the allocation. In the current LTE implementation of per second to carry traffic and control signals. results of this MIMO, the receiver receives two different signals Every sixth subcarrier (i.e., every 90 KHz) carries research will be applicable to Antenna port 0 Antenna port 1 inform design Resource element decisions for any (available for data or R0 R0 R1 R1 high-speed wireless control symbols) data system. R0 R0 R1 R1 Not allocated for this antenna port Subcarriers R0 R0 R1 R1 Reference symbol for this antenna port R0 R0 R1 R1

Symbols

Figure 1. LTE reference signals in time and frequency.

30 Telecommunications and Information Technology Planning

a reference signal that the user equipment logging devices that could be used in the field uses to determine channel conditions and to study MIMO signal characteristics. whether there is sufficient SNR to allow MIMO Another capability of the SDR devices under transmission. However, as shown in Figure 1, investigation is their use as radio transceivers, these reference signals only occur in specific rather than just passive listening instruments. 70 microsecond time slots and their locations As the LTE signal characteristics become better in frequency are a function of the identification understood, ITS believes that SDR test instru- number of the base station that is transmitting ments could be used to produce specialized test them. The Public Safety Broadband Research waveforms as well as act as “lite” user equip- project has been able to recover this signal us- ment nodes for existing LTE base stations, with ing high-speed sampling spectrum analysis and the closed loop communication and control decode these reference signals. that would be required for an experiment of Application of these techniques requires this type. This capability would be nearly unique knowledge of the antenna properties as well among existing LTE test instrumentation, and as the radio channel characteristics within the would allow much greater flexibility in active operational area. The Public Safety Broadband network testing. Research project has measured prototypical Conclusions MIMO antennas inside an anechoic chamber Both of these efforts are by no means re- using standard vector network analyzer tech- stricted to use in the public safety spectrum, but niques and is also investigating the use of high could easily be expanded to include civilian LTE. speed time domain methods to resolve the Although the immediate goal is to provide the impulse response of the antenna systems under public safety community with guidelines and test. Research is also ongoing to use the fine measurements about network tuning to opti- structure properties of the reference signals to mize the MIMO capabilities and maximize spec- determine propagation conditions and establish tral efficiency, the information being gathered is the specific requirements under which real- useful across a wide range of scenarios. Indeed, world channels can support MIMO propaga- MIMO promises to be one of the most useful tion. This requires the use of specialized MIMO tools needed to achieve the spectral efficiency drive test tools capable of resolving the indi- targets in current Federal policy. This work can vidual signals received by at least two antennas help ensure informed decisions about its use in at the same instant (Figure 2). Signal processing Federal high-speed wireless data systems. algorithms are being tested to develop methods of determining the channel transfer matrix from measured radiated signals. SDR Test Instrument Technologies The effort described above requires the use of laboratory grade test instruments, but another aspect of the Public Safety Broadband Research project involves the use of inexpensive software- defined radio (SDR) platforms to accomplish many of the field measurements needed. MIMO measurements require the use of multiple phase For more locked receivers to assure time synchroniza- information tion in the channels being measured. Meeting contact: this requirement is expensive with current test Dr. Robert B. instruments, but the function has recently be- Stafford come available in the universal software radio (303) 497-7835 peripheral (USRP) class of devices. This raises Figure 2. Public Safety Broadband Research Stafford@its. the possibility of relatively inexpensive signal laboratory test instruments. Photo by Ken Tilley. bldrdoc.gov

31 Over the past 12 years, ITS has employed approximately 75 students from across the country through the Student Temporary Employment Program (STEP). These STEP participants are vital to ITS Linh Vu projects and are MS Electrical Engineering critical for the University of Colorado at Denver Sarah McKenna future of ITS and BS Biology telecommunica University of Pennsylvania tions research. Some students transition to the Student Career Experience Program (SCEP). After graduation, SCEPs have the option to remain at ITS. ITS retains approximately 10% of its student employees. Currently, three SCEPs have graduated and Kristen Davis George Engelbrecht stayed in the E BS Computer Information Systems BS Electrical Engineering Division. Metropolitan State College of Denver University of Colorado at Boulder

Dr. Joel Dumke PhD Electrical Engineering Purdue University

32 Telecommunications Engineering, Analysis, and Modeling

Telecommunications Engineering, Analysis, and Modeling

he Telecommunications Engineering, Analysis, and Modeling Division conducts studies in these Tthree areas for wireless and wireless-wireline hybrid applications. Engineering encompasses technical assessment of telecommunications systems, their components, and their performance, including the impact of access; interoperability; timing and synchronization; and susceptibility to noise, jamming, and interfering signals on system effectiveness in national security/emergency preparedness (NS/EP), military, and commercial operational environments. Analysis is often performed in association with the TA Services project, which offers custom analytical tools via an online cooperative research and development agreement (CRADA). Propagation prediction models are being incorporated into GIS formats and Web-based access. Modeling is one of ITS’s core strengths enabling contributions to international and national standards bodies. Propagation models are used in conjunction with terrain databases and other data, like population. Adaptations of historic models, and application-specific models, have been developed, enhanced, and compared. Unique propagation models are developed for specific applications to meet sponsor requirements.

Engineering Propagation Modeling Website: The Interference Issues Affecting Land-Mo- Institute continues to develop a suite of GIS- bile Systems: ITS participates in ATIS subcom- based applications for propagation modeling mittee WTSC-RAN (Wireless Technologies and and performance prediction. This powerful GIS Systems Committee—Radio Access Networks) format complements ITS’s propagation predic- and in ITU-R Working Party (WP) 5D. ITS devel- tion capabilities. The work is funded by the U.S. oped PCS interference models for CDMA and Department of Defense. W-CDMA. The project is funded by NTIA. Modeling Public Safety Video Quality (PSVQ): The Broadband Wireless Standards: ITS devel- PSVQ project conducts subjective tests on video ops radio propagation algorithms and methods compression and artifacts that are shown to to improve wireless system spectrum usage. ITS expert viewers. From these data, NTIA/ITS has prepares technical contributions supporting made recommendations for video standard Rec. U.S. interests in 3G broadband wireless systems ITU-T P.912. Also, ITS leads yearly VQiPS work- for ITU-R Study Group 3, WPs 3J, 3K, 3L, 3M. shops. This project is funded by NIST/OLES. ITS is active in path-specific model development Fading Characteristics Verification: ITS for WP 3K and its development of ITU-R Recom- participates in many aspects of public safety mendation P.1812. Work is funded by NTIA. communications. This project is investigating Integration of the Empirical and the whether the fading experienced with public Undisturbed-Field Models: ITS is developing safety communications can be modeled using a model for short-range (1 m to 2 km) propaga- Rayleigh fading. This project is funded by NIST/ tion between mobile radios. The propagation OLES. work consists of propagation model develop- Analysis ment and field measurements. This project is Telecommunications Analysis Services: funded by NTIA/OSM. ITS provides network-based access to research Earth-to-Space Propagation Models: ITS results, models, and databases supporting propagation engineers build on existing models For more wireless system design and evaluation. These previously developed for other agencies to ac- information services are available to Government and non- complish technology transfer on a global level contact: Government customers and are funded through to standards groups such as the International Patricia Raush, an online CRADA. Telecommunications Union (ITU). Division Chief (303) 497-3568 praush @its.bldrdoc.gov

33 Inter-system interference is a Interference Issues Affecting Land significant Mobile Systems challenge to the increasing numbers Outputs of wireless • Contributions to industry-supported efforts for predicting, identifying, and mitigating communications interference-related problems systems and users crowding into the • Technical support for international and national standards development organizations available spectrum. • Self-interference model for evaluating CMRS technologies and deployment of The ability to adjacent-channel systems as described in a NTIA Report design effective technologies to Overview non-interoperable systems servicing the same mitigate and avoid n 2010, the President signed a Memoran- geographical area will further reduce wireless such interference Idum1 proposing to release 500 MHz of Fed- network channel capacity. One way of cop- depends on eral and commercial spectrum over a 10 year ing with degraded infrastructure is to deploy accurate models period to support the development and deploy- temporary equipment to supplement surviving derived from a ment of next-generation commercial commu- systems. National security/emergency prepared- clear nication systems. As a result, existing (legacy) ness (NS/EP) planners and network operators understanding of systems will be forced to share the remaining need to have knowledge of interference issues, interference issues. spectrum without operational degradation. system dynamics, and load patterns to efficiently However, such Even with this additional spectrum, throughput and effectively deploy supplemental equipment tools are not demands from commercial and Government in an overloaded environment. effective without users will always outpace availability as newer Spread-spectrum technologies, which make agreement on their technologies are developed. In addition, the efficient use of allocated spectrum and are use and a increasing telecommunication needs of civil and relatively unaffected by noise, are used in current standardized Federal users (such as emergency responders) and next-generation cellular systems, but suffer approach to impose their own unique spectrum require- from limitations due to issues such as co-channel dealing with ments. Globally, attempts to implement true interference. Work in detecting, identifying, and interference universal coverage (worldwide roaming) place mitigating co-channel interference in congested affecting mobile different demands on spectrum allocations de- environments requires tools that can characterize communication pending on the locations of users and providers. the interference experienced by these systems. systems. Interference Issues Industry Efforts Concerning Until advanced dedicated communication Interference Issues systems for emergency services are deployed, ITS provides propagation and interference ex- Commercial Mobile Radio Services (CMRS) pertise to the commercial sector through its par- will continue to be used for backup emer- ticipation in national and international standards gency communications. As a result, wired and development organizations. ITS contributed to wireless communication services experience the understanding of inter-system interference elevated usage rates during emergency situ- in personal communications services (PCS) by ations. This sudden influx of traffic by private, participating in the development of the Telecom- commercial, civil, and Federal users will result munication Industry Association’s (TIA) Technical in system overloads, a decrease in signal qual- Service Bulletin Licensed Band PCS Interference ity, and further disruption of service in affected (TSB-84A). This handbook was a first step in ad- areas. Beyond the physical damage caused by dressing the interfering environment caused by destructive events, additional factors such as large numbers of active systems and competing co-channel and adjacent-channel interference technologies by proposing methods to identify, and the operation of multiple, independent, avoid, and mitigate (see figure) various forms of interference. Since the completion of this work, 1. The White House, Presidential Memorandum: coverage of interference issues concerning all mo- “Unleashing the Wireless Broadband Revolution,” bile communication systems has been adopted June 28, 2010, http://www.whitehouse.gov/ the-press-office/presidential-memorandum- by the Alliance for Telecommunications Industry unleashing-wireless-broadband-revolution Solutions (ATIS) sub-committee WTSC-RAN

34 Telecommunications Engineering, Analysis, and Modeling

Internal External Other External (Self) Interference Noise Interference

System Geometry

Transmitter TX Antenna Path Loss RX Antenna Receiver C Characteristics Characteristics Characteristics Σ Characteristics Characteristics Ν + Σ Ι

Performance Dynamic Metrics Responses DOWNLINK Module

Performance Dynamic Metrics Responses Module UPLINK

C Receiver Rx Antenna Path Loss Tx Antenna Transmitter Ν + Σ Ι Characteristics Characteristics Σ Characteristics Characteristics Characteristics

System Geometry

Internal External Other External (Self) Noise Interference Interference

Detailed diagram of proposed process to estimate interference between competing land mobile systems. (Wireless Technologies and Systems Committee – An Interference Model for Radio Access Networks). Work on the successor Spread Spectrum Technologies to TSB-84A is currently underway through a joint ATIS/TIA effort, Proposed Joint ATIS/TIA Standard on Coexistence and Interference Issues in Land Mobile Systems. ITS continues its involvement in ITS developed an interference model for two this activity as issue champion and editor. code division multiple access (CDMA) based systems: the TIA/EIA95B standard and W-CDMA Support for International (wideband CDMA). This interference model is Standards Development described in NTIA Report 10-467, “A Co–Chan- The International Telecommunication Union nel Interference Model for Spread Spectrum – Radiocommunication Sector (ITU-R) is the lead Technologies.” The model produces representa- organization in the effort to coordinate world- tions of instantaneous air-interface signals for wide development of future telecommunication scenarios involving multiple base stations with systems and spectrum allocations. ITU-R Work- variable numbers of mobile handsets for each ing Party 5D (WP 5D) has been coordinating base station, and includes both forward- and the efforts of government and industry in the reverse-link processes. The sampled signal con- development of a global broadband multimedia tribution of each base station and handset is international mobile telecommunication sys- calculated separately, including power control tem, known as IMT. Coordinating world-wide as a gain factor of the baseband filter. Then frequency allocations is a near-impossible task, all signals identified in a specified scenario are given the disparity in the historical evolution of summed together to form a composite output frequency use and the requirements and regu- signal. Software- and hardware-based simula- For more lations of individual countries. Interference and tions can use the sampled signal produced by information coexistence issues are a primary concern as more the model to evaluate system designs. These contact: systems try to use the same limited quantity of simulations can characterize one-on-one, one- Timothy J. Riley spectrum on a worldwide basis. To advance this on-many, and many-on-one interference modes (303) 497-5735 work, ITS supplies technical support as a mem- and can help solve existing congestion problems triley ber of the U.S. delegation to WP 5D. and anticipate potential problems. @its.bldrdoc.gov

35 Public safety practitioners rely Public Safety Video Quality (PSVQ) heavily on video Outputs: technology as a tool by which to • Guide to Defining Video Quality Requirements, to help public safety agencies specify keep the Nation video equipment safe. Poor quality • Technical contributions to standard bodies to establish video quality measurements video footage can and standards for the public safety community have serious • Technical contributions on video quality standards to the sponsor implications and may mean the Overview Working Group (WG) under DHS in 2009. The difference between olice and fire agencies often purchase ra- purpose of the VQiPS WG is to provide the life and death. As dios, cameras and other communications public safety community with the knowledge video technology P equipment based on just their local needs. Un- to purchase and employ the most appropriate has evolved, the fortunately, this equipment may not always be video systems for their requirements, and to equipment options of sufficiently high quality for use in certain ap- collectively communicate public safety practitio- have become plications, nor standardized enough to enable ners’ needs to industry and standards-making increasingly agencies to communicate with other agencies. bodies. complex. Unbiased This is because, until recently, there were no The WG’s main initiatives are: guidance is technical standards for emergency communica- • Development of a set of application-inde- essential for tions equipment. To improve communications pendent usage scenarios, or generalized use practitioners to for public safety agencies, ITS is conducting classes (GUCs) clearly articulate audio and video quality research to determine • Development of Defining Video Quality Re- their video quality standard parameters for levels of quality of quirements: A Guide for Public Safety (Fig- needs and make communication systems based on the specific ure 1) to help public safety agencies perform informed video needs of public safety practitioners and their the following: system purchasing applications. The PSVQ project is working on -- Assess video needs decisions. behalf of the Department of Homeland Secu- -- Match needs to technical performance rity (DHS) and the Department of Commerce’s specifications and standards to support Public Safety Communications Research (PSCR) procurement program to ensure that first-responder video -- Develop a glossary of common terms systems communicate clearly and accurately -- Compile an inventory of existing standards with each other. and specifications that address various components of the video system for specific VQiPS Working Group GUCs To address this need, the PSVQ project -- Develop a common library of test clips that formed the Video Quality in Public Safety (VQiPS) represent GUCs

Figure 1. Defining Video Quality Requirements: A Guide for Public Safety is available as both a printable PDF (from the DHS SAFECOM site) and as an interactive online primer (from PSCR.gov).

36 Telecommunications Engineering, Analysis, and Modeling

The Guide is the central framework for organizations and academic institutions; and Web Sites for containing and disseminating the work of the industry leaders. Ultimately, the VQiPS series Additional other three initiatives, and for any performance of workshops will help to coordinate efforts in Information specifications developed by PSVQ in the future. establishing quality requirements for video used Its purpose is to assemble in a single repository in public safety applications. PSVQ Web site: all technical guidelines for use in video system Phase 1 of the Guide was published in July http://www.pscr. design and specification that achieve the de- 2010, and VQiPS will continue as an annual gov/projects/ sired system usage across multiple disciplines. workshop to address the WG initiatives on an video_quality/ The Guide will inform policy makers and pro- ongoing basis. video_about.php curement officials who are engaged in the selection of video systems. The desired usage Network Performance PSCR VQiPS Web across disciplines will drive applicable technical Specification Testing site: http://www. pscr.gov/projects/ requirements. These requirements will facilitate In support of the Guide, PSVQ performed a video_quality/vqips/ the preparation of video system specifications study to determine network performance speci- vqips.php for the public safety end user. fications that apply to a subset of the VQiPS VQiPS Workshop GUCs. The study investigated how the interac- SAFECOM VQiPS tion of several aspects of a video scene (object Web site, with In February 2011, PSVQ hosted the fourth publications: VQiPS workshop (Figure 2). The workshop’s size, scene motion, and scene lighting) and http://www. goal was to bring all users of video in the network conditions (resolution and bitrate) af- safecomprogram. public safety community together to continue fects the ability of a practitioner to recognize an gov/ progress on the VQiPS WG initiatives. A wide object within a scene. The test report contains a currentprojects/ range of participants attended, including lo- set of recommendations for H.264 compression videoquality cal, state, and Federal representatives from a and video resolution specifications for several variety of disciplines such as law enforcement, VQiPS GUCs. These recommendations will be fire services, and Emergency Medical Services incorporated into subsequent versions of the (EMS); representatives from non-profit research Guide.

For more information contact: Dr. Joel Dumke (303) 497-4418 Figure 2. VQiPS Working Group meeting during the February 2011 VQiPS Workshop in Boulder, jdumke Colorado. Photo by Ken Tilley. @its.bldrdoc.gov

37 Fading channel models are used to Fading Characteristics Verification predict signal loss Outputs in telecommunica tions and ensure • 40 GB of measurements taken in residential and low-rise urban environments at 162 reliable wireless and 793 MHz communications. • NTIA Technical Memorandum describing the measurement effort and analysis results The most commonly used Overview Most models were developed long before the model incorporates ireless communications experience tem- advent of complex modulation techniques the Rayleigh Wporal variations in received signal level (and, in some cases, before the advent of radio continuous characteristic of the propagation channel; these communications itself). ITS undertook a re- probability variations are referred to as fading. Fading at examination of the fading channel to determine distribution, first VHF and above is predominantly caused by if assumptions implicit in the understanding derived over a the complex scattering environment through of fading channels are appropriate in light of century ago. As which the radio waves travel. Large and small the persistent desire to increase bit density in telecommunica scale scattering from either stationary or mobile limited spectral bandwidths. This effort involved tions equipment objects creates a multitude of propagation the measurement, analysis, and assessment of becomes paths between the transmitter and the receiver. propagation fading to understand the limita- increasingly Each scatterer reflects the transmitted signal at tions of classical fading theories when applied complex in an attenuated level and with a unique phase. to increasingly sophisticated modulation tech- response to The received signal is an aggregate of all these niques. The ultimate purpose of this effort was increased spectrum scattered paths and results in multipath fading. to investigate the statistical fading behavior of crowding, it is As a result of this characteristic of the propa- the radio channel within time frames significant important to verify gation environment, receivers need to be highly to the reception of digitally-modulated signals. that these models sophisticated to maintain reliable communica- Fading is typically modeled as a statistical are accurately tions. More complex modulation techniques are distribution, either Rayleigh or Rician, depend- informing design needed to minimize the effects of fading due ing on whether a line-of-sight (LOS) component decisions by to the constraints of limited spectral resources. is present. The Rayleigh fading model has been comparing In an effort to increase spectral efficiency, the the most widely-used distribution model and is theoretical typical digital modulation constellation relies considered to represent the worst case condition predictions to on high levels of symbol discrimination in am- because it does not contain an LOS component. actual plitude, phase, and frequency. The ability of a This worst case assumption is suspect since measurements. receiver to detect slight variations in the modu- there are known conditions where Rayleigh pre- lated signal requires that error-inducing channel dictions are too ideal. Three assumptions must effects be well understood and accommodated. be met for true Rayleigh behavior: Project Challenges 1. The interfering waves must be randomly Since scattering can be described statisti- varying in phase and of nearly equal power cally, most theoretical models are the result of 2. The phases of the component waves must matching statistical models to measured data. be randomly distributed between 0 and 2π

38 Telecommunications Engineering, Analysis, and Modeling

Nakagami-m Value data. Measurements were also Related 1 conducted on a Rayleigh channel Publication: 0.95 simulator and the significance of C. Redding, C. 0.9 channel fading on the Project 25 Behm, T. Riley and 0.85 protocol was analyzed. R. Stafford, 0.8 Measurements “Examining the validity of Rayleigh 0.75 To provide different fading distribution 0.7 conditions that are relevant to assumptions in Nakagami-m Value Value Nakagami-m public safety, measurements were 0.65 characterizing the conducted in residential and low- 0.6 fading channel at rise urban environments at both 0.55 162 and 793 MHz,” 162 and 793 MHz frequencies. NTIA Technical 0.5 The residential environment was 0 500 1000 1500 Memorandum located in south Boulder and Acquisition Number TM-11-477, Figure 2. Plot of Nakagami-m values <1.0 for all data files in the low-rise urban in downtown Jun. 2011. a single run. Boulder (Figure 1). The measurement system simu- 3. There must be a minimum of five interfering lated an LMR base station and mobile subscriber waves scenario and consisted of a transmitter placed While assumptions 2 and 3 are borne out at a static location and a mobile receiver. The in most urban/suburban environments in the transmitter was configured to transmit a 400 800/900 MHz band, it is more difficult to satisfy ms long continuous-wave (CW) signal once per assumption 1. It is improbable that the condi- second. The receiver and transmitter were syn- tion of nearly equal power interfering waves chronized via a Global Positioning System (GPS) would be met in an actual environment and the unit, which also supplied the location of the randomness criteria can be easily violated by receiver at the instance of each measurement. the presence of a direct (or predominant) wave Data was collected at speeds between 8 and component. This supports the contention that 100 km/h (i.e., walking and vehicular speeds). measurement results rarely compare well with Analysis the Rayleigh distribution across the entire fad- The recorded data was analyzed to determine ing signal range. how closely it aligned with the Rayleigh fad- The phase variation of the channel has not ing distribution model. Approximately 26,000 been well studied, probably because empirical measurements were collected at the two propa- data about channel phase is hard to obtain. gation environments and two frequencies. A Although some analytical results about channel number of analyses were performed on the phase correlation based on Rayleigh assump- data and the results suggested that the Rayleigh tions are available, questions as simple as the model did not accurately reflect the measured typical rate of channel phase variation in real fading environment. In one telling analysis, the environments are not addressed in the research data was fitted with a Nakagami-m distribution literature. This is troubling, since most digital curve at the 95% confidence level (Figure 2). modulations in use today depend heavily in In over half of the cases (51.2%) the m param- whole or in part on phase modulation. If the eter was less than one, indicating worse than channel is causing rapid phase variations in time Rayleigh conditions. The high incidence of this For more regimes on the order of a symbol period, bit er- channel behavior argues for more study using information rors will result in the decoded signal. the fast sampling short time regime conditions contact: This project attempted to verify whether suggested by this experiment. It is clear that, in Christopher the Rayleigh fading model is an appropriate the time regimes characteristic of high-speed Redding model for land mobile radio (LMR) channels data radio operation, the incidence of worse (303) 497-3104 at public safety frequencies by analyzing the than Rayleigh conditions is much higher than credding statistical characteristics of measured fading previously suspected. @its.bldrdoc.gov

39 Telecommunica tions Analysis Telecommunications Analysis Services Services enables Outputs the transfer of ITS propagation • Internet access on a cost-reimbursable basis linking U.S. industry and Government models developed agencies to the latest ITS engineering models and databases over seven decades • Contributions to the design and evaluation of broadcast, mobile, and radar systems, of research to personal communications services (PCS), and local multipoint distribution systems (LMDS) private industry • Standardized models and methods of system analysis for comparing competing and other designs for proposed telecommunication services Government agencies. The TA • Online cooperative research and development agreements (CRADAs) that allow users Services Web site to task ITS to develop special models or perform special analysis tasks provides access to user-friendly tools Overview (30 m) and 3 arc-second (90 m) terrain data for that assist in the he Telecommunications Analysis (TA) the U.S. and world-wide GLOBE (Global Land design of effective TServices program provides U.S. industry One-km Base Elevation) terrain data, the U.S. wireless systems. and Government agencies with access to the Census data for 2000 and 1990, Federal Com- Organizations latest ITS research and engineering outputs on munications Commission (FCC) databases, and ranging from large a cost-reimbursable basis. Services are provided geographic information systems (GIS) databases Federal agencies through a series of computer programs designed from the Environmental Systems Research Insti- and Fortune 500 for non-technical users with minimal computer tute (ESRI). Over the past 20 years, TA Services U.S. companies to expertise or in-depth knowledge of radio propa- has developed both general-use propagation single person gation. The services are updated as new data and models for broad application across various fre- consulting methodologies are developed by the Institute’s quency bands and application-specific models businesses can use engineering and research programs. used for a particular type of analysis such as these models and TA Services also allows users to work closely high definition television (HDTV). Customers tools on a cost with ITS engineering staff to customize research with active accounts can use these models via reimbursable basis. and development models and their respective the TA Services Web site. Users can select mod- programs via the online cooperative research and els, enter information about their broadcast development agreement (CRADA). Users can cre- equipment, and produce transmitter coverage ate tasks for a cost of up to $25,000 per CRADA. diagrams for an application. Through the TA Services Web site, new CRADAs These coverage maps follow FCC guidelines can be quickly created as needed. and requirements for Grade A and Grade B coverage showing both the signal coverage and the Available Models and population that resides within the various analy- Databases sis contours as specified by the user. Specifically, Currently, TA Services provides access to many TA Services offers raster-based population databases and services including 1 arc-second maps that support more accurate population

Figure 1 (left). Sample output of the CSPM model of a broadcast transmitter in New Jersey. Figure 2 (right). Composite coverage of several Coast Guard stations located along the East Coast.

40 Telecommunications Engineering, Analysis, and Modeling

calculations than vector-based maps. TA Ser- vices also maintains a catalog of FCC recorded television stations and advanced television stations from which data for these analyses can be drawn. Users can also combine individual transmitter coverage data into a composite coverage map. This allows the user to determine both single-transmitter performance and integrated system performance with accurate population calculations. Notable Projects Public Broadcasting Service (PBS) TA Services has assisted the U.S. Public Broadcasting Service (PBS) with the transition to digital television (DTV) by providing an application-specific model for use in advanced television analysis. This model allows users to create scenarios of desired and undesired station mixes. For example, a DTV broadcast station can run an interference application with other nearby DTV stations, as shown in Figure 1. The results of these studies show those areas with new interference, and the population and Figure 3. Coverage studies without (top) and number of households within those areas, so with (bottom) an ocean clutter loss addition to that designers can mitigate possible situations CSPM. before they become a problem. The model can also determine how much a selected station’s system, using the most recent Census informa- interference is affecting other stations. This al- tion. Plans include the addition of the Census lows engineers to make modifications and then 2010 information as soon as it becomes avail- determine the effect those modifications have able. TA Services’ work with PBS serves to verify on the interference emissions that affect other that agency is also meeting a similar population surrounding stations. In addition to creating coverage requirement. graphical plots of signal levels, the program cre- National Public Radio (NPR) ates tabular output that shows the distance and The National Public Radio (NPR) Laboratories bearing from the selected station to each poten- used the CRADA capabilities to develop an in- tial interfering station as well as a breakdown of band, on-channel (IBOC) interference model the amount of interference each station in the and plan to do similar development for HDTV. study contributes to the total interference. An example of this type of analysis is shown in For more National Weather Service (NWS) Figure 3. information TA Services has also assisted the National In FY 2009, ITS began the effort to upgrade contact: Weather Service (NWS) in determining their sys- the TA Services System to a new GIS Web-based Paul M. McKenna tem coverage and public outreach. The NWS is a interface that will place the power of advanced (303) 497-3474 major public service provider required to ensure GIS functions and features in the hands of TA pmckenna that more than 95% of all Americans have ac- Services customers. This work continues as @its.bldrdoc.gov cess to potentially life-saving information in the funding is available. For more information on or event of a national emergency. Figure 2 shows an available programs, see the TA Services entry in George A. example of an NWS system coverage map. With the Tools and Facilities section (page 84) or Engelbrecht the use of the TA Services system and databases, call one of the contacts listed here. (303) 497-4417 this national alert system was able to improve gengelbrecht and verify the coverage of their large, diverse @its.bldrdoc.gov

41 Accurate propagation Propagation Modeling Website modeling is an Outputs essential component of • A custom-tailored and installed Propagation Modeling Website (PMW) Geographic wireless Information System (GIS) software suite for multiple DOD customers communications • Ability to simultaneously run a batch of transmitters, as specified in an Excel® planning, and transmitter file accurate • Ability to mosaic DTED1, DTED2, SRTM1, SRTM2 or custom terrain files for use in a geographic propagation analysis information is a critical input for • Use of parallel threading to decrease propagation analysis time proportional to the accurate modeling. number of computer cores ITS has developed • Ability to composite thousands of transmitter analyses to predict regional wireless openly available network coverage for system planning and interference detection for national security propagation and public safety modeling tools that use commercial Overview available. In response to the increasing use of Geographic dvanced Geographic Information System commercial GIS tools, over 10 years ago ITS cre- Information (GIS) models have become an important ated a desktop tool called the Communication Systems (GIS) to A tool in recent years for predicting the perfor- Systems Planning Tool (CSPT) based on ESRI both acquire mance of communication systems. Government ArcGIS® ArcObject software and customized geographic data operations, including those for public safety and VB6.0 software. and display national security, depend critically on our ability geographic From CSPT to PMW to successfully predict propagation in a variety coverage areas. As CSPT currently contains propagation models of environments and conditions. Over the past users migrate to four years, ITS has developed the Propagation for the following frequency ranges: LFMF (low/ Web-based Modeling Website (PMW), a web-based GIS medium frequency) from 150 kHz to 2 MHz, HF systems, the tools propagation modeling tool, customized to (high frequency) from 2 MHz to 30 MHz, and must also migrate meet the propagation prediction needs of the VHF (very high frequency) from 20 MHz to 20 to being Web- Department of Defense (DOD) sponsors. GHz. Applications can range from worldwide accessible. The PMW project builds on 30–40 years outdoor coverage studies to indoor propaga- of ITS expertise in evaluating and analyzing tion studies of one building in an urban envi- propagation models. ITS developed TA (Tele- ronment. The CSPT tools can download FCC FM communications Analysis) Services, a propaga- and TV databases, perform overlap, composite, tion modeling tool based entirely on FORTRAN and interference studies and can report demo- software, more than thirty years ago, before graphic information from the 1990, 2000 and commercial GIS components, database systems, 2007 (estimated) Census Population databases. or sophisticated Web development tools were CSPT leverages the existing stand-alone GIS

Figure 1. An example of the PMW GIS Web map page showing an analysis of four transmitter coverage plots.

42 Telecommunications Engineering, Analysis, and Modeling

Figure 2. A block diagram of the PMW architecture; asterisks indicate planned future functionality. product suite; however, the CSPT and GIS Ar- The PMW also incorporates a parallel threaded cInfo software must be installed on each desk- design that offers speed improvements over the top machine with a license for each machine. CSPT single threaded model. Also, each set of terrain data files, imagery data Over the next several years, as the PMW con- files, antenna pattern files, and transmitter files tinues to mature, the DOD and other sponsors need to be copied onto each CSPT machine or may choose several software enhancements, made available via a shared network system. including but not limited to: interference Four years ago, ITS began migrating the VHF studies, new analysis results export formats portion of the CSPT software from a stand-alone (Google Earth™ (KML/KMZ) or open-source desktop solution into a web-based solution GIS maps), new terrain formats (HRTe, LIDAR, called the PMW, accessed through a browser IFSAR, etc.), and other propagation models (the interface as shown in Figure 1. The PMW pro- ITS undisturbed-field model, HF models and vides intranet users with Web-accessible propa- indoor-outdoor models). gation models, a central imagery/data storage The PMW is currently customized to fit the facility, and a central database location to store needs of our DOD sponsors and operate on all propagation analyses, using just one set of their internal, secure networks, running ITS-de- licensed software, as diagrammed in Figure 2. veloped and third-party propagation coverage Maintaining, operating and upgrading the sys- models for one or more VHF transmitters. How- For more tem are streamlined. ever, other implementations of the PMW can information The software currently includes the capac- be tailored to meet individual customer needs. contact: ity to perform: TIREM 3.15 and Longley-Rice Due to the large selection of GIS databases, Julie Kub propagation analysis, analysis composite cre- customers can choose to include terrain, satel- (303) 497-4607 ation for thousands of transmitters, database lite and aircraft imagery, ground transportation jkub propagation parameter and measurement stor- infrastructure, building data, and population @its.bldrdoc.gov age, transmitter spreadsheet server uploads, distribution. By developing TA Services, CSPT, or bulk transmitter analyses, antenna pattern file and PMW, ITS has aided Government agencies, George server uploads, terrain file server uploads, data private cellular companies, public and private Engelbrecht input validation, 2D GIS transmitter and data radio and television stations, transportation (303) 497-4417 displays, data analysis export to CSPT and third- companies, and consultants to efficiently man- gengelbrecht party GIS applications, and login access control. age their telecommunications infrastructure. @its.bldrdoc.gov

43 Success in worldwide telecommuni- Broadband Wireless Standards cations markets, as Outcomes well as effective and compatible use • Preparation for and Support of the 2011 Block Meetings of ITU-R Working Parties 3J, of telecommunica- 3K, 3L and 3M and Study Group 3 tions technologies • Development of sections of the handbook on the use of ITU-R propagation both domestically recommendations for interference and sharing studies and abroad, is vital • Ongoing measurements of interference from/to radar systems and communications to the long-term systems economic health of the U.S. To achieve Overview hertz of combined radio frequency spectrum for these goals and ver the last decade, the radio frequency evaluation, all presently allocated to other Fed- further its Ospectrum has become increasingly im- eral exclusive and Federal/non-Federal shared 3 objectives with portant for enabling communications and com- services. The Plan also describes a process for regard to all forms munications networks’ support of ubiquitous evaluating each of the candidate bands and of wireless commu- wireless dissemination, collection, manipulation the steps necessary to make them available for nication on a global and analysis of digital information. A seamless wireless broadband services. An essential com- basis, the U.S. and continuous wireline connection to one’s ponent of the Plan is its formal recognition of Administration computing device is no longer needed to access the critical importance of electromagnetic inter- participates in the the Internet with very acceptable latencies. As ference protection for all Government missions/ single most a result, it is projected that the supply of spec- services that rely on spectrum use. important world- trum currently allocated for these uses will soon In addition to its domestic activities in support wide telecommuni- be insufficient to satisfy future users’ demand, of the Plan’s ambitious goals, NTIA has worked dil- cations regulatory requiring that more bands of spectrum be made igently with other Federal agencies and the FCC to and standardiza- available either by reallocation or sharing. promote international broadband wireless access. tion body, the In recognition of this projected increase in There is now a U.S. Administration contribution, International spectrum demand, a recently issued Presidential in the form of a draft Agenda Item to the ITU-R Telecommunica- Memorandum1 directed the Commerce Depart- World Radiocommunication Conference-2015 tion Union – Radio- ment, working cooperatively with the Federal (WRC-2015), containing several key elements that communication Communications Commission (FCC), to identify extend domestic policy goals for expanded wireless Sector (ITU-R). and make available a combined new bandwidth broadband use to the international arena. The ITU- of 5 × 108 hertz of radio frequency spectrum, R WRC is the only venue through which changes over the next 10 years for expanded wireless can be made to the ITU Radio Regulations, the broadband use. The Wireless Innovation and In- international treaty that defines the rights and ob- frastructure Initiative2 (Wi3) also highlights the ligations for use of the radio spectrum worldwide. Administration’s commitment to an expanded Fundamentally, this U.S. Administration con- wireless broadband policy. tribution (which must be adopted by WRC-2012 NTIA released a “Ten-Year Plan and Timetable in order for action to be taken by WRC-2015) to Make Available 500 Megahertz of Spectrum seeks to expand global allocations of spectrum for Wireless Broadband” (the Plan) to meet the for wireless broadband by modifying the Radio President’s broadband spectrum goals. With Regulations to provide for additional primary inputs from the Policy and Plans Steering Group allocations to the mobile service, with no limita- (comprised of Assistant Secretaries from Federal tions being placed on the frequency bands to agencies), the Plan identifies over 2.2 × 109 be considered. The U.S. contribution has four basic objectives: • Flexibility, in terms of frequency bands to be 1. The White House, Presidential Memorandum: “Unleashing the Wireless Broadband Revolution,” considered June 28, 2010, http://www.whitehouse.gov/ the-press-office/presidential-memorandum- 3. National Telecommunications and Information unleashing-wireless-broadband-revolution Administration, “Ten Year Plan and Timetable 2. The White House, “Fact Sheet: President to Make Available 500 Megahertz of Spectrum Obama’s Plan to Win the Future through the for Wireless Broadband,” http://www.ntia. Wireless Innovation and Infrastructure Initiative,” doc.gov/report/2010/ten-year-plan-and- February 10, 2011, http://www.whitehouse.gov/ timetable-make-available-500-megahertz- sites/default/files/microsites/ostp/Wi3-fs.pdf spectrum-wireless-broadband-pre

44 Telecommunications Engineering, Analysis, and Modeling

• Harmonization through common spectrum allocations to the mobile service • Joint studies across the ITU-R, to ensure consideration of all critical existing services • Timely action at WRC-2015 To meet the objectives of spectrum flexibility and harmonization for the joint studies to be conducted by the ITU-R, prudent spectrum management practice dictates that predicted harmful interference must be minimized both to and from the existing, incumbent services and the new (i.e., mobile) services. Median Field Strength Predictions using Rec. ITU-R General purpose radio propagation P.533 as described in the Handbook. prediction models are powerful tools for building international consensus around the sections related to a Recommendation for introduction of these new services. They provide which that engineer has specific expertise and accurate methods for the evaluation of the experience. potential for interference arising from proposed Certain of these sections involved detailed spectrum reallocation and/or sharing scenarios. descriptions of how to use the model(s) in that When these radio propagation prediction Recommendation to provide sample predic- models are also recommended international tions for an example sharing or interference standards (i.e., Recommendations), they are scenario, including Recommendations ITU-R generally perceived as technically neutral and P.533, P.1546 and P.1812. The figure shows an unbiased bases for multilateral coordination, example using Rec. ITU-R P.533 to predict the regulation, and harmonization of spectrum. median field strength at Tangier, Morocco, for a Within the Broadband Wireless Standards 24 hour period (UT) in June, 1994, from a 500 project, four ITS engineers participate in one or kilowatt transmission originating in Belgrade, more Working Parties for the development of Serbia, for frequencies between 2 MHz and 30 ITU Recommendations. Notably, ITS engineers MHz. Other sections with ITS authors involved currently serve as the Chairman of the ITU-R the application of the time and location variabil- Working Party (WP) 3K and the Head of Delega- ities of these models to interference and sharing tion (i.e., the official spokesperson) for the U.S. studies and definitions for technical terms used Administration at the meetings of ITU-R Study in the recommendations and the handbook. At Group (SG) 3 and its Working Parties. its meeting, SG 3 decided to delegate adop- Technical Contributions tion and approval of this handbook to the next Member states provide input to the ITU stan- meeting of ITU-R WP 3M in 2012. dardization process by preparing technical con- A second U.S. contribution, prepared by ITS, tributions that are presented to WPs and SGs proposed revisions to the irregular terrain dif- to inform the discussion and provide a basis for fraction method employed in Recommendations the language of the Recommendations that are ITU-R P.526, P.452 and P.1812, using a variant eventually released. Among recent U.S. contri- of the delta-Bullington multiple knife-edge plus butions that ITS helped prepare, one concerned smooth sphere diffraction method. Major revi- For more a handbook on the use of SG 3 Recommenda- sions of two of these Recommendations (P.526 information tions for interference and sharing studies. In and P.1812) were approved for adoption by SG contact: support of the correspondence group tasked 3. The revision of Recommendation ITU-R P.452 Paul M. McKenna with development of the handbook, four ITS was appended to the WP 3M Chairman’s Report (303) 497-3474 engineers were assigned authorship for one in order to permit Administrations to conduct pmckenna or more sections of this handbook, typically further testing of the proposed revision. @its.bldrdoc.gov

45 Accurate radiowave Integration of the Empirical and the propagation Undisturbed-Field Models models are vital for interference Outputs analysis and • ITS Undisturbed-Field and Empirically Derived (ITS_UFED) radio-wave propagation coverage model based on analytical predictions and measured data developed for use with predictions. ITS ultra-low antenna heights and close-in distances continues to improve model • A new tool to meet the needs of spectrum management and electromagnetic accuracy by compatibility analysis processes developing new Overview propagation model for interference analysis and methods better coverage predictions in an environment where suited to the he tremendous growth in demand for broadband wireless networking services would rapidly changing mobile wireless devices requires that the T be deployed. Low antenna height and low radio environment. problems of interference between existing and power broadband wireless terminals are needed In particular, ITS new radio spectrum users be addressed. An to permit operation of these systems and at the developed a new accurate and flexible radio-wave propagation same time avoid interference with other systems model which is model is essential to meet the needs of spectrum in a crowded electromagnetic spectrum. In this more accurate than management and electromagnetic compatibil- type of environment, the antennas are situated previous models ity analysis processes. ITS was tasked by the Of- at heights so low that they are immersed in the when predicting fice of Spectrum Management to integrate two surrounding environmental clutter. The anten- propagation at low previously developed radio-wave propagation nas may also be very close to each other. antenna heights, models into a self-contained model. The Empirical Model is a slope-intercept close distances, low One model is the Empirical Model based on model based on measured data taken by ITS power, and in the least squares fit to measured data resulting in a cluttered and complex radio environment. cluttered from an ITS measurement campaign performed The data was collected from radio-wave mea- environments. in three vastly different environments: rural, surements performed in and around Denver These urban low-rise/suburban, and dense urban and Boulder, Colorado, using a pseudo-mobile characteristics are high-rise/city. The other is the deterministic and typical of analytically based Undisturbed-Field Model, broadband wireless which is suitable for very short-range propaga- uses, like cellular tion distances and very low antenna heights. The and mobile devices result was the ITS Undisturbed-Field and Empiri- in a downtown cally Derived (ITS_UFED) Model for radio-wave area. Drive tests propagation loss prediction for very low antenna through various heights (1 to 3 meters) and close-in distances (2 cluttered meters to 2 kilometers) between antennas over environments the frequency range of 150 to 6000 MHz. provided the The model is unique in its ability to work necessary data to seamlessly over these difficult combinations support of parameter ranges. The combined model development of can be applied for use in system performance each of these prediction as well as prediction of interference individual models phenomenon. It is based on both analytical cal- and their culations from the physics of electromagnetic integrated result. theory and actual measurements. The model is the result of a combined program at ITS of measurements and model development to more accurately predict radio signal propagation. The ITS receiver van performing propagation The Empirical Model measurements in the downtown Denver dense The Empirical Model was developed in re- urban high-rise city environment. Photo by sponse to a need for an accurate radio-wave Robert Johnk.

46 Telecommunications Engineering, Analysis, and Modeling

test procedure with a fixed transmitter loca- and the surface wave. Since this is a line-of- Related tion while the receiver van was driven over a sight model, the ground is assumed to be flat Publication: specified route. The measurements were ob- over the distance of 2 kilometers or less with N. DeMinco, tained at seven nominal frequencies: 183, 430, no irregular terrain present. For distances of less “Propagation loss 915, 1602.5, 2260, and 5750 MHz, since the than 5 kilometers the curvature of the Earth prediction propagation characteristics are expected to be has a negligible effect and can be assumed to considerations for frequency dependent. The raw signal-strength be flat for frequencies less than 6 GHz over a close-in distances measurements and positions were post-pro- smooth Earth. The Undisturbed-Field Model as a and low-antenna cessed to yield basic transmission loss values separate model can be used for antenna height height versus distance for each nominal frequency and ranges from 0 to 3 meters and frequencies from applications,” transmitter location. 150 MHz to 6000 MHz, but when integrated NTIA Report Based on these measurements, the Empirical into the ITS UFED Model the antenna heights TR-07-449, Model attempts to mirror some of the general are limited to the range of 1 to 3 meters for Jul. 2007. trends in the data. In the case of distance de- smooth transitions with the Empirical Model. pendence, the model fits a power law via linear least-squares estimation. For the frequency ITS Undisturbed-Field and and environmental dependences, where only Empirically Derived Model discrete values are available, the model main- The ITS Undisturbed-Field and Empirically tains separate categories. If a prediction at a Derived Model is a combined model with a frequency other than one of the nominal values hybrid procedure using both the Empirical and is required, interpolation between the mean Undisturbed-Field models. The principal moti- values and standard deviations is performed to vation for its development is the fact that the estimate the basic transmission loss. empirical model adjustments at “short” ranges The Undisturbed-Field Model were less accurate than making adjustments based on the Undisturbed-Field Model. The Undisturbed-Field Model is a deter- The combined model avoids discontinui- ministic method suitable for very short range ties between the two models as users vary the mobile-to-mobile propagation, for distances of model parameters of antenna heights, distance, 2 to 30 meters. The model has been shown to frequency and the combined percentage of be accurate for flat terrain up to 2 kilometers. time and locations. It does this by establishing a The minimum distance is based on staying at set of breakpoint distances. distances greater than the distance where the reactive field of the antenna is present. The breakpoint distances were selected by Extensive testing with exact models at close-in observing where computations made with both distances has verified the computation accuracy models were equal for the same scenario of for distances as close as 2 meters over the 150 frequency, antenna heights, and environment. MHz to 6000 MHz frequency band. For the median quantile of (combined) time and The method involves the calculation of the locations and at distances less than the break- undisturbed electric field and calculation of point distance, the combined model uses the Undisturbed-Field Model to predict the basic the loss based on the amplitude of the electric For more transmission loss. For the median quantile of field as a function of distance, frequency, and information, (combined) time and locations and at distances the ground constants. The undisturbed field is contact: greater than the breakpoint distance, the com- the electric field produced by a transmitting an- Nicholas DeMinco tenna at different distances and heights above bined model uses the empirical model to predict (303) 497-3660 ground without any field-disturbing factors in the basic transmission loss. These breakpoint ndeminco the proximity of the receiver antenna location. distances are functions of the environments, the @its.bldrdoc.gov The undisturbed electric field technique in- antenna heights and the frequency. The break- or cludes near-field effects, the complex two-ray point distances also depend on the desired Paul McKenna model, antenna near-field and far-field response quantile of time and locations. (303) 497-3474 pmckenna @its.bldrdoc.gov

47 Radio propagation models are Earth-to-Space Propagation Models empirical Outputs mathematical equations that • Technical support for international telecommunication standards organizations predict path loss • Producing U.S. technical contributions to the ITU-R. along a • Major revision to Recommendation ITU-R P.528-2. transmission link or the effective • Participation in domestic and international working groups studying Earth-to-space coverage area of a communication links. transmitter. Each telecommunication Overview Supporting International link encounters n describing the President’s broad approach Standards different Ito freeing up spectrum for mobile and fixed ITS uses its technical work and expertise to conditions, so wireless broadband use, the White House support U.S. interests in the Radiocommuni- different models reported: “In recent years, the amount of in- cations sector of the ITU (ITU-R), a technical are needed to formation flowing over some wireless networks agency within the United Nations. The ITU-R predict has grown at over 250 percent per year.”1 The develops international standards called Recom- propagation for ”spectrum crunch” is further exacerbated by the mendations. Entities such as administrations, different types of fact that only a limited portion of the regulated businesses, or academia can use these Recom- links under radio spectrum—the frequencies between ap- mendations to study, plan and develop radio- proximately 600 MHz and 20 GHz—is the most different communication systems. viable to use for practical systems. This means conditions. Many Study Group 3 of the ITU-R is responsible for that in addition to reallocation and repackag- international Recommendations in the P-series, which pertain ing of individual bands, spectrum sharing will standards for to propagation issues. ITS, with its history of be increasingly relied on to accommodate ris- propagation propagation modeling, is well suited to sup- ing demand. On a global level, several wireless modeling are based port Study Group 3 work. Of particular interest on models communication systems are investigating the this past year has been Recommendation ITU-R developed by ITS possibility of sharing frequency spectrum. P.528-2. This Recommendation was developed from our uniquely Propagation Modeling for from an ITS model, IF-77. extensive data Spectrum Sharing collection. ITS Recommendation ITU-R P.528 Successful spectrum sharing requires careful continues to make planning to avoid interference between differ- It is critical that the model used in frequency significant ent users. Any study for sharing the spectrum sharing studies involving aeronautical and satel- contributions to in a frequency range needs to apply an ap- lite systems be appropriate for the situation. In updating those propriate propagation model in order to obtain many cases, Recommendation ITU-R P.528-2 is models—some of reasonably realistic predictions of the results of the appropriate model to use. In the 2010 Study which were first a particular sharing scenario. Satellite systems Group 3 Working Party meetings, the study published over half are especially vulnerable candid ates for spec- group received questions about two separate a century ago—to trum sharing: mistakes are costly to correct and issues. One issue concerned frequency sharing reflect might even be unfixable. Unfortunately, there studies between the Earth stations of mobile sat- contemporary are few appropriate propagation models avail- ellite services (MSS) and satellite remote sensing conditions and able for aeronautical and satellite wireless links. (SRS) services. The other concerned frequency equipment. ITS is committed to supporting the effort to sharing studies between terrestrial mobile sys- use frequency spectrum efficiently. Our work tems and aeronautical radionavigation systems includes ensuring that the methods for accurate (ARNS). The appropriate Recommendation to and realistic planning are available to both Fed- use was P.528. Recommendation ITU-R P.528-2, eral and civilian users. however had not been updated since 1986. The recommendation was technically correct, but 1. The White House, “Fact Sheet: Doubling the almost unusable in its existing form. Amount of Commercial Spectrum to Unleash the ITS headed a correspondence group effort Innovative Potential of Wireless Broadband,” June to revise P.528-2 using the IF-77 model devel- 28, 2010. http://www.whitehouse.gov/the-press- office/fact-sheet-doubling-amount-commercial- oped at ITS for the FAA. The correspondence spectrum-unleash-innovative-potential-wireles group expanded the set of graphs and added

48 Telecommunications Engineering, Analysis, and Modeling

Curve Set for Basic Transmission Loss at 600 MHz for 10% of the Time for h2 = 20,000 m 100

120

140

160 h1 = Free Space

180 h1 = 1.5m h1 = 15m 200 h1 = 30m 220 h1 = 60m 240 h1 = 1000m h1 = 10,000m

Basic Transmission Loss (dB) Loss Transmission Basic 260 h1 = 20,000m 280

300 8016014012011 1001 1201 1401 1601 1801 Distance (km)

Figure 1 (top). Graph showing basic transmission loss curves for 600 MHz, one of the added frequencies in the expanded curve set for the proposed revision of Recommendation ITU-R P.528‑2. Figure 2 (above). ITS staff (fifth row) as part of the U.S. delegation to working party meetings of the ITU-R Study Group 3 in Geneva, Switzerland. Informal photo courtesy ITU-R SG3 archives. frequencies, time percentages and antenna presently developing a computational method heights that were badly needed. The group for the Recommendation in the next ITU-R study also added a method for interpolating across cycle. Again, the basis for this work will be the five parameters, making the document more ITS propagation model IF-77. Users could use usable. The revision to the Recommendation this computational method to calculate interfer- was accepted in October 2011 and is being ence levels with other systems and separation For more circulated for final approval before adoption. distances between Earth-based stations. information Such calculations are essential to studies to contact: System Planning evaluate frequency sharing proposals. The cal- Teresa L. Rusyn ITS is supporting U.S. interests by continu- culations based on the computational method (303) 497-3411 ing the work of the correspondence group in are also important in planning both satellite and trusyn revising Recommendation P.528. The group is aeronautical systems. @its.bldrdoc.gov

49 Investigations are performed in the major areas of broadband wireless systems performance in the presence of interference; the development of new, short-range radio propagation models; the effects of noise and interference as critical limiting factors for advanced communication systems; automated tools for assessing audio and video quality; and the further development of advanced spectrum sharing concepts.

Dr. Robert Johnk of the ITS Theory Division prepares a maritime radar receiver for interference-effects testing for an other-agency sponsor. Such work is critically important in spectrum-sharing studies performed by the Institute. Photo by Frank Sanders.

50 Telecommunications Theory

Telecommunications Theory

s demand for telecommunication spectrum grows, more bandwidth is sought by governments Aand industry. Wireline networks meet many needs, but some needs can only be met by using radio spectrum—a limited resource. In response, spectrum use is migrating toward self-controlled, interference-limited technologies that use spectrum dynamically. Historic spectrum band allocations on a service basis (i.e., separate bands for different systems) are being blurred and supplanted by more sharing between services. But the successful development and implementation of new sharing depends on development of new capabilities in radio systems to avoid interference. New knowledge, focused on improvements in network performance, is needed to understand the levels of interference that radio systems can withstand from other systems. Tools to monitor the quality of audio and video information on communication channels are also needed so that quality levels can be adjusted in real time to achieve maximal quality with minimal bandwidth. To achieve these goals for the U.S. Government and the private sector, the Institute’s Telecom- munications Theory Division performs telecommunications research, improving systems at fundamental levels of physics and engineering. Through technical publications, cooperative research and development agreements (CRADAs), and interagency agreements, ITS continuously transfers the results of its research to both the public and private sector, where the knowledge is transformed into better telecommunications for the U.S., new and better products for consumers and the Govern- ment, and new opportunities for economic development and growth for the economy.

Audio Quality Research Electromagnetic Compatibility ITS conducts research and development Assessments for Radars and leading to standardization and industry imple- Communication Systems mentation of perception-based, technology-in- In response to interference problems to radar dependent quality measures for voice and other receivers from non-radar systems operating in audio communication systems. The project is and adjacent to radar bands, ITS performed ex- funded by NTIA. tensive analyses and measurements jointly with OSM, including on-site measurements at loca- Effects of the Channel on Radio tions across the country. Two different problems System Performance recently caused widespread interference to Gov- ITS researches the effects of interference and ernment weather radars in two radio bands; in noise on the performance of radio receivers and FY 2011 technical solutions were developed and networks. Current work is focused on the effects initial tests were performed that demonstrated of noise and interference as limiting factors in methods and approaches that solve these prob- the performance of radar and communication lems for radars in both bands. systems. The project is funded by NTIA. RSEC Compliance Electromagnetic Analysis and Measurements on New Radars Compatibility Solutions ITS performed measurements on the emissions of new high-power radars for the In response to radio and radar interference Lockheed Martin Company (LMCO) at LMCO problems, ITS performs analyses and measure- facilities at Syracuse, NY, and near Yuma, AZ, ments jointly with NTIA’s Office of Spectrum to determine whether new LMCO radars meet Management (OSM). The work is funded both the requirements of the NTIA Radar Spectrum by NTIA and by other Federal agency or CRADA Engineering Criteria (RSEC). This ongoing work sponsors. In FY 2011, ITS worked with the U.S. is funded under a CRADA with LMCO. For more Coast Guard to analyze electromagnetic compat- information, ibility and proactively determine solutions for Video Quality Research contact: potential problems between maritime radars and The Institute develops perception-based, Frank Sanders other services in the event that 3 GHz spectrum technology-independent video quality measures (303) 497-7600 is shared between radars and other services. This and promotes their adoption in national/interna- fsanders@ work is being continued in FY 2012. tional standards. The project is funded by NTIA. its.bldrdoc.gov

51 As the variety of devices and Audio Quality Research complexity of the Outputs infrastructure for wireless • Technical publications and presentations on new research results transmission of • Measurements and estimates of speech and audio quality and algorithm performance audio signals • Algorithms and data supporting speech and audio coding and quality assessment increases, methods and protocols for digital audio Overview these factors. As such, the program generates and communicates new scientific understand- encoding and igital audio encoding and transmission transmission also Dhave enabled a host of telecommunica- ings of the complex technical system known as “telecommunications.” More specifically, the become more tions and entertainment services and products. program identifies, develops, and characterizes complex and These include voice over Internet Protocol innovations for speech and audio coding and varied. Many (VoIP), cellular telephones, automatic speech transmission that may increase quality, robust- factors influence recognition, Internet digital audio streaming, the perceived ness, or flexibility, or that may decrease bit-rate, and digital audio broadcasting. Digital audio quality of audio delay, or complexity. In addition, the program encoding and transmission has matured but ef- transmissions. The seeks to advance tools and techniques for op- ficient, robust, and flexible signal transmission ITS Audio Quality timizing the trade-offs between these factors. at reduced bitrates with good fidelity remains Research Program Optimization often requires measurement of an elusive goal governed by a complex set of studies the ways in speech and audio quality and measurement trade-offs. The trade-off between signal quality which all these can be very challenging due to the interplay be- and encoded bitrate is the most apparent, but factors interact tween technical parameters, human perception, robustness (to transmission errors and losses) and can be and human judgment. configured to and adaptability (to different signal classes, efficiently and bandwidths, quality levels, coding rates, or Speech Quality Dynamics effectively optimize robustness levels) also come into play, and all Telecommunication systems are increasingly perceived quality. of these can influence coding and transmission heterogeneous and adaptive. The network New tools and delay as well as algorithm complexity. resources available to support a call are likely algorithms The ITS Audio Quality Research Program un- to change during the that call, especially when developed by ITS dertakes research efforts that lead to new under- one or more call participants are mobile. The are transferred to standings of the complex relationships between inevitable result is that speech quality increases industry, Government, and 3.5 academia to promote innovation, entrepreneurship, 3 existing market development, and commercialization 2.5 of competitive new technologies. Quality (MOS)

1.5 0 10 20 30 40 50 60 70 80 90 Time (Seconds)

Figure 1. Example speech quality time history (in blue) along with three versions with reduced variation. Vertical axis shows speech quality in Mean Opinion Score (MOS) units.

52 Telecommunications Theory

and decreases during a call. An example time- reduction. This approach stands in vivid contrast Related history of speech quality is shown by the blue to conventional speech coding algorithms that Publications line in Figure 1. require extensive numerical processing but also S. Voran and A. Through laboratory and literature research, achieve greater reductions in bit rate. The new Catellier, “Gradient Program staff have determined that quality approach may be beneficial in specialized ap- Ascent Subjective variations are generally detrimental to overall plications where power or processing resources Multimedia Quality quality. It is no surprise that drops in quality are are highly constrained, including some mobile Testing,” EURASIP undesirable. But it is also true that in some cases communication applications and remote sens- Journal on Image increases in quality are also undesirable. Overall ing applications. and Video perceived speech quality for a call is determined Processing, vol. Additional Work jointly by the average quality, the minimum or 2011, Article ID worst-case quality, and the amount of quality Throughout FY 2011, program staff per- 472185, 14 pages, variation during the call. formed speech and audio quality testing using March 15, 2011. doi: Following from these results, staff have been both objective and subjective techniques, sup- 10.1155/2011/472185 experimenting with techniques that reduce porting this and other ITS programs. Laboratory quality variations. Robust coding techniques facilities were upgraded and staff continued S. Voran and A. can mitigate decreases in speech quality in to transfer program results to industry, Gov- Catellier, “Multiple- some cases. But once those techniques are ex- ernment, and academia through technical description speech hausted, the only remaining avenue to reducing publications along with lectures and poster pre- coding using quality variations is to place artificial limitations sentations. Staff also served in numerous peer speech-polarity on quality increases. In Figure 1 the green, red, reviewer and associate editor capacities for the decomposition,” in and cyan lines illustrate examples of mild, mod- technical paper publication process in support Proc. of the IEEE erate, and strong limitations respectively. The of the international speech and audio research Global progression blue, green, red, cyan in Figure 1 Communications community. Program publications, technical is a progression of reduction of speech quality Conference, Miami, information, and other program results are variation, and this is desirable. But at the same FL, Dec. 2010. time it is inevitably a progression of reduction of available at http://www.its.bldrdoc.gov/audio. average speech quality, and this is undesirable. The goal is to balance these two forces (quality variation and average quality). This balance point is linked to several different parameters associated with the original quality. Ultra-Low Complexity Speech Coding Program staff are also developing a new approach to encoding high quality speech at reduced bit rates. This approach uses only look-up tables and thus requires virtually no Figure 2. Audio mixer that controls subjective numerical processing. It achieves a modest rate tests. Photo by Andrew Catellier.

For more information, contact: Stephen D. Voran (303) 497-3839 svoran@its. bldrdoc.gov

53 ITS broadband wireless research Broadband Wireless Research develops more Outputs accurate radio channel • Identification of flaws and development of corrections for a widely-disseminated measurement channel-power model methods and tools, • Measurement system for propagation model development sponsored by the Office of performs real-world Spectrum Management (NTIA/OSM) measurements, and • Measurements to support ITS propagation model development supports development of • Development of new fast-fading measurement tools for mobile propagation better propagation measurements models. The results • First prototype development of a new wideband channel sounder using commercial- of this research— off-the-shelf equipment disseminated through propagation database for the development of publication and Strategic Objective mobile-to-mobile propagation models covering technology he goal of the NTIA/ITS Broadband Wire- ranges of two meters to eight kilometers. These transfer—help to less project is to measure the radio channel T systems were deployed in seven different envi- improve the in real-world environments and to provide data ronments ranging from the deep urban canyon competitiveness of to facilitate the development of improved radio of downtown Denver (Figure 1) to the open the U.S. channel models. The results of this research rural farm country outside of Boulder, Colorado information and are disseminated to the wireless community (Figure 2). Both wideband and narrow band communications through NTIA technical reports, journal publi- systems were deployed over a wide frequency technology sectors, cations, conference presentations, seminars, range of 183–5750 MHz. The data obtained and enhance and national and international standards bod- were used to develop sophisticated path loss scientific ies such as ANSI and the IEC. Results are also models that will help OSM develop interference knowledge through provided to other NTIA and ITS groups for the models of portable and mobile radios. Through a greater development, maintenance, and improvement technology transfer, these systems and the data understanding of of radio channel propagation models. obtained can be made available to commercial the radio channel. Program Overview entities such as AT&T, other Government agen- The Broadband Wireless project is currently cies such as the Department of Defense, and engaged in the development of ultrawideband, academic research institutions such as Ohio wideband, and narrowband propagation mea- University for further research and development. surement systems, channel modeling, statistical Modeling and Research data analysis, signal processing algorithms, and development of specialized RF emissions mea- Measuring the average power of a mobile ra- surement systems. dio signal is important for mobile radio system design because it is used for various controls, Mobile Propagation especially for handoff decisions. It is therefore Measurements important that this power be measured accu- The program is developing propagation rately. A well-known paper by Lee1 presents a measurement systems to study the mobile criterion for determining the uncertainty and propagation channel. Two systems have been associated confidence level of the average mea- developed: sured power. A close examination of this paper • A patented wideband pseudorandom noise revealed a number of mathematical errors that (PN) channel sounder system that performs make this criterion overly optimistic. In view of both time- and frequency-domain channel the fact that this is a well-known rule of thumb, parameter measurements it is important that the engineering community • A narrow-band system that has high dynamic be made aware of its fallacies. ITS researchers range and excellent interference immunity Under the sponsorship of the NTIA’s Office 1. Lee, W.C.Y., “Estimate of local average power of a mobile radio signal,” IEEE Transactions on of Spectrum Management (NTIA/OSM), ITS Vehicular Technology, vol. 34, no. 1 , pp. 22- 27, used these systems to build a comprehensive Feb. 1985. doi: 10.1109/T-VT.1985.24030.

54 Telecommunications Theory

are writing a report that identifies and corrects with antenna separation of a few meters to out- the mathematical errors and presents corrected door environments with antenna separation of conclusions. 250 meters. This system has provided precision path loss information and delay-spread data for Ultrawideband Propagation the development of propagation models. Measurement System Boeing, United Launch Alliance (ULA), Development Hewlett-Packard, the National Aeronautics and The Broadband Wireless Research project is Space Administration (NASA), and the U.S. currently developing a short-range ultrawide- Navy have expressed interest in either having band propagation measurement system that ITS engineers apply this system to a particular covers a frequency range of 10 MHz–18 GHz. problem they are researching or having this It uses a combination of a vector network ana- capability transferred to them. The system lyzer, an optical link, and a pair of transmit/re- has also been used collaboratively to support ceive antennas. This system performs low power other programs within NTIA/ITS, most nota- stepped-frequency measurements that are post bly to measure soil properties at the ITS Table processed to obtain high-dynamic range data Mountain Field Site (see the paragraph on Free in both the time and frequency domains. It Field Measurements of the Electrical Properties has been deployed in a variety of environments of Soil in the article “Table Mountain Research ranging from short-range indoor environments Program,” page 16).

Figure 1. An “urban canyon” contains a large variety of materials, angles and shapes that can reflect or scatter radio waves and present one type of challenge for propagation modeling.

Figure 2. Open rural areas and long distances present different challenges for accurate modeling. In this photo, the ITS Radio Spectrum Measurement Science (RSMS) truck has been deployed to take measurements in a rural location. For more Photos by Robert Johnk. information contact: Dr. Robert Johnk (303) 497-3737 bjohnk@its. bldrdoc.gov

55 Effective spectrum sharing and Coast Guard Spectrum Reallocation spectrum Study reallocation can only be Outputs accomplished if • Radar interference protection criteria both legacy and new services • Interference testing methodologies operating in the Overview In FY 2010, the U.S. Coast Guard contracted same or adjacent with ITS to investigate effects of reallocation on bands can be pectrum reallocation is often necessary protected from Sto accommodate new services which can S-band marine radars. There are two aspects to interference so potentially increase business productivity and this problem. First, the marine radar community they can fulfill their enhance the private lives of citizens. However, needs to define interference protection criteria missions. First, the reallocating services to bands near legacy ser- (IPC) that can be used by regulatory agencies to vices or, in some cases, in the same band used interference determine maximum transmitted power levels by the legacy service can cause interference potential must be for the reallocated service and minimum sepa- understood and which prevents the legacy service from fulfilling ration distances between the reallocated service quantified. Then its mission. transmitters and marine radar receivers. Regula- mitigation methods Reallocation can cause interference in three can be devised, ways. First, reallocating services to nearby bands tory agencies of interest in this regard are the tested and can introduce weak unwanted out-of-band or International Telecommunications Union (ITU), standardized. spurious signals into the legacy radio detec- National Telecommunications and Information tion bandwidth. This interference cannot be Administration (NTIA), and Federal Communi- mitigated by legacy receiver filtering. The real- cations Commission (FCC). located service must mitigate the interference Second, the marine radar community needs by reducing unwanted power and maintaining to know how to test whether a marine radar a minimum separation distance. can perform in the presence of other radio Second, reallocating services to nearby bands can cause legacy radio receivers not properly systems which satisfy the IPC. The testing meth- protected from strong signals outside the de- odology must be approved by test standards tection bandwidth to behave non-linearly. This groups such as the United Nations/International can cause gain compression, higher receiver Electrotechnical Council (UN/IEC). noise levels, and intermodu- lation. This problem can be mitigated by legacy receiver filtering. However when this is not feasible, the reallocated service must also mitigate the interference by reducing power and maintaining a minimum

separation distance. BRS Basestation Third, reallocating services to the legacy radio band can cause co-channel interference. For example, reallocation could combine different radar services into the same band. In another Coast Ocean example, communications links Figure 1. Interference scenario showing a network of BRS using spectrum sharing tech- basestations contributing to the interference power. BRS niques could be reallocated into basestation height allows the BRS signal to travel significant the radar band. This can cause distances. The BRS signal can cause the radar to not see the interference when the sharing boat between the BRS basestation and the ship using the technique fails. radar. This can be hazardous in foggy conditions.

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Current Work probability of detection required for various ra- In FY 2011 we investigated the first potential dar targets. The ITS radar model was then used threat: weak unwanted spurious signals from to determine the allowable interference to noise a communications link. In this case the com- ratio (INR). munications link is from the broadband radio Once the allowable INR was known, a link service (BRS). The BRS is the next generation power budget was developed to determine the of personal communication services which will propagation loss needed to meet the allow- provide wideband Internet communications to able INR. The link power budget included the mobile users. power from all the basestations. This is referred Figure 1 depicts the interference scenario. to as aggregate power by spectrum engineers. The BRS basestations are laid out in a grid on Propagation and antenna pattern losses deter- land. The BRS antenna is attached to a tower mine how much of each basestation’s power is which is high enough to transmit the BRS sig- included in the aggregate power. nal to significant distances over the water. The Finally, the minimum separation distance is larger ship is using an S-band marine radar to determined from the propagation loss using detect the presence of the smaller ship between propagation models. Propagation loss in the it and the shore. maritime temperate environment varies with Analysis began with creating an interference location and time. Statistics of these variations model as shown in Figure 2. The model can be allow one to predict the percentage of time the divided into five sections: the radar transmitter, radar will not meet its performance objective— radar propagation channel, radar receiver, BRS i.e., its percent outage. transmitters, and interfering signal propaga- In preparation for work in FY 2012, ITS also tion channel. The radar propagation channel assembled a test bed for evaluating the effect of is assumed to be free space due to the narrow strong signals on radar IPC and began measure- radar antenna beamwidth. The interfering signal propagation channel includes the effects of ments. The test bed consists of a radar circulator, ducting. limiter, and low-noise front end components. Next, the allowable degradation was de- The first measurements evaluated the frequency termined, based on a degradation of the response of these components. Subsequent measurements evaluated

Radar Channel s, n, i LNFE gain compression pt lst g lp g grx γ(np) γ(1) lsr, 1 s (t) lsr, 2 and noise enhancement. TX ANT ANT + + IFF |X|2 INT DET i (t) n (t) Finally, work began on Radar transmitter RCS σ GN kTofn assembling a test bed for ^ ^ ^ ~ pt lst pbrs gt, 1 lp, 1 g1 measuring radar to radar TX TF ANT ANT interference. This test bed ^ ~ gt, 2 lp, 2 g2 lpol TX TF ANT ANT Σ will allow researchers to in- ject interfering signals into

g^ ~ g t, n lp, n n Radar Receiver the radar antenna terminal TX TF ANT ANT and digitize the received

BRS transmitter Interference radar pulse and interfering Channel signal just before and just after the radar detector. Of Figure 2. Interference model showing radar transmitter, radar For more particular interest is evalu- propagation channel, radar receiver, BRS transmitters, and interfer- information ence propagation channel. TX represents a transmitter, ANT an ating the effect of high contact: antenna, RCS a radar cross section modulation source, GN a Gauss- duty cycle solid state radars Robert J. Achatz ian noise source, MF a matched filter, ED an envelope detector, INT on the performance of (303) 497-3498 an integrator, and DET a detector. The sawtooth shaped symbol low duty cycle magnetron rachatz represents a loss. radars. @its.bldrdoc.gov

57 The radio channel is the “information Effects of the Channel on Radio System super-highway” Performance over which a wireless signal Outputs travels. As • Error statistics for degraded radio channels channels become increasingly • Definition of relationships between channel characteristics and error statistics crowded, the • Radio system design parameters traveling signal • Interference protection criteria encounters more impediments. Overview the rate at which errors occur or as complex as Undesired signals, elecommunications play a vital role in the mean time between errors. attenuation, and Tproviding services deemed essential for One of the more challenging tasks for this multipath can all modern life. Many of these services use radio project is to devise methods of collecting er- cause degradation links composed of a transmitter and receiver, ror statistics while the radio link is being de- of a wireless i.e., the radio system and the channel over graded. Depending on the link, these statistics transmission. which its radio waves are propagated. Common are obtained through mathematical analysis, Characterizing examples are television and radio broadcasts, simulation, or hardware measurements. Ideally, these impediments cellular phones, wireless local area networks, they are obtained by two or more methods to and their impact and radar. improve reliability. on radio The channel, which can vary widely—as, These statistics are used in a variety of ways transmission is a for example, an urban area or an office envi- to improve the design of radio systems and the necessary ronment—is often the primary impediment to regulation of their operation. Designers use prerequisite to reliable radio system performance. Potential them to help determine radio system design designing and degradation due to channel characteristics has parameters such as transmitted power, error regulating wireless wide ramifications for designing radio systems correction gain, and channel equalization gain. systems that can and regulating their operation. The fundamen- Regulators use these statistics in determining deliver their tal purpose of this project is to understand interference protection criteria (IPC), which information intact the effects of the channel on radio system designate the maximum amount of interfering despite the performance and apply this knowledge towards signal power a receiver can tolerate without impediments in the improving the design of radio systems and the compromising its own performance. Reliable channel. regulation of their operation. IPC become more important as pressure in- The channel degrades radio system per- creases for Government services to share radio formance by introducing undesired signals, spectrum with private services in accordance attenuation, and multipath. Undesired signals with the recently introduced National Broad- include natural noise created by phenomena band Plan. such as lightning, man-made noise generated Current Work by electrical devices, and signals from other radio systems. Attenuation is the loss of aver- Work this year consisted of the continued de- age signal power caused by obstructions in velopment of a radar model, investigating radar the radio environment such as hills, buildings, IPC, measuring the effects of strong signals on or walls within a building. Multipath is due to low noise amplifier noise floors, and planning reflections, diffractions, and scattering off these and hosting spectrum sharing forums for the same objects. International Symposium on Advanced Radio Undesired signals and attenuation reduce Technologies (ISART) 2011. signal power margins. Multipath causes signal One area of focus is the development of a fading, inter-symbol interference in digital radar model for radar interference studies. This communications systems, and clutter in radar model is timely, since radars use a large portion systems. All of these lead to an increase in the of the federal radio spectrum and industry is number of errors, and error statistics provide currently advancing a number of proposals for the performance metrics by which the effect sharing it. The focus has shifted from modeling of the channel on radio system performance is magnetron radars using non-coherent integra- quantified. These statistics can be as simple as tion to more modern solid state radars using

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Related Publication: R.J. Achatz, R.A. Dalke, and J.J. Lemmon, “In- building radio enhancement systems for public safety,” NTIA Report TR-11-480, Sep. 2011.

Project team members. From left to right Robert Achatz, Mike Cotton, and Roger Dalke. Photo by Frank Sanders. coherent integration. The coherent integration that strong signals raise the noise floor of the is implemented with a discrete Fourier trans- low noise amplifier. The test bed will be used form. In FY 2012, the radar model will be used to determine if the strong signal changes the to assist the U.S. Coast Guard in analyzing the statistics of the noise. The results of this experi- effect of signals from 4th generation broadband ment will help to determine whether Gaussian personal communication service devices on the noise assumptions can be used for determining performance of marine radar systems in nearby IPC for strong signal situations. radio bands. In FY 2011, ITS contributed to developing In FY 2011, ITS investigated how using meaningful IPC by planning and moderating fluctuating radar targets would affect radar IPC a variety of spectrum sharing forums for ISART values. In the past, radar IPC have been derived 2011, the 12th annual ISART sponsored by the from measurements which assume a static ra- NTIA and hosted by ITS. Through these forums, dar target. However, aviation and marine radar leaders from government, industry, and uni- specifications and acceptance tests typically as- versities are brought together to present and sume fluctuating radar targets. Analysis showed discuss their views on various spectrum sharing that using a fluctuating radar target would issues. increase the amount of interference power that Knowledge gained through research in one the receiver would tolerate. Additional work is project is often applied towards other projects needed to verify this result in the laboratory. at ITS. For example, in FY 2011, the Institute’s Development of a low noise amplifier test knowledge of the radio channel was applied For more bed was also started. The test bed will be used to evaluating the effectiveness of public safety information to analyze the effect of a strong signal on the in-building radio enhancement systems (IBRES). contact: noise floor of a low noise amplifier. For some The results of this evaluation are an important Robert J. Achatz time, radio engineers have known that strong resource for municipal public safety commu- (303) 497-3498 signals drive low noise amplifiers into gain nications professionals tasked with assisting rachatz compression. Radio engineers have also known building owners to install reliable IBRES. @its.bldrdoc.gov

59 As radio spectrum crowding increases, Interference Effect Tests, interference issues Measurements, and Mitigation for arise more frequently. Weather Radars Mitigation depends Outputs on accurately identifying both • Predictions of the effects of interference from non-radar systems to weather radars the source and the • Measurements of interference characteristics at weather radar sites and identification mechanism of of interference sources and mechanisms across the US in two bands (3 GHz and 5 interference. ITS is GHz) skilled at interference root • Development of new dynamic frequency selection (DFS) test-and-certification cause analysis, as protocols to prevent future interference to 5 GHz weather radars from DFS wireless well as developing transmitters mitigation • Determination of interference sources and mechanisms affecting 3 GHz weather techniques. radars across the U.S. • Development of interference-mitigation techniques for 3 GHz weather radars

Overview supposed to share the band with the radars on n FY 2011, ITS and OSM engineers inves- a not-to-interfere basis, has occurred despite Itigated and provide solutions for ongoing a dynamic frequency selection (DFS) technol- radio interference to weather radars in two ogy feature that should preclude the problem. bands (3 GHz and 5 GHz) at sites across the DFS is supposed to provide a detect-and-avoid United States. An NTIA Technical Report, the capability for the frequencies used by the band- second in a three-part series, was issued on sharing 5 GHz U-NII transmitters. the 5 GHz problem. It followed up on original It was determined that most models of DFS- field work (described in Part I of the series) by equipped 5 GHz U-NII devices are operating describing controlled-condition laboratory work properly; a small sub-set of models, however, that provided solutions for the 5 GHz weather have not detected in situ radar signals. Detailed radar interference. tests and measurements on a variety of 5 GHz Interference to Weather Radars DFS U-NII devices at the ITS lab in Boulder in the 5 GHz Band demonstrated that the device models that were The 5 GHz interference, originating from not detecting weather radars were nevertheless unlicensed national information infrastructure detecting DFS test-and-certification radar wave- (U-NII) wireless communication devices that are forms. The problem is being corrected by using

Interference effects in a weather radar receiver.

60 Telecommunications Theory

better test-and-certification DFS waveforms, (FAA), and the private sector, has determined Related provided by ITS to the FCC. the sources of the interference and has pro- Publication vided a range of solutions that are now being Interference to Weather Radars John E. Carroll implemented. This work involved extensive field in the 3 GHz Band Geoffrey A. operations at locations across the US and labo- Sanders Frank H. Interference to weather radars at 3 GHz has ratory work in 2011. The field operations used Sanders Robert L. been caused by an entirely different problem. ITS suitcase measurement systems to determine Sole, “Case Study: Here, the problem has turned out to be due to the sources of interference and to gather the Investigation of adjacent-band emissions. ITS, working jointly data that were needed to identify a solution to interference into 5 with the National Weather Service (NWS), the problem. An NTIA Report describing this GHz weather the FCC, the Federal Aviation Administration work will be issued in 2012. radars from unlicensed national information infrastructure devices, Part II,” NTIA Technical Report TR-11-479, Jul. 2011.

Above: ITS and other Government engineers performing field measurements to identify interference sources. Below: An ITS engineer performs electromagnetic compatibility measurements inside a weather radar bubble 24.4 meters (80 feet) above the ground while observers from the FCC, FAA, and NWS observe. Photos by Frank Sanders

For more information, contact: Frank Sanders (303) 497-7600 fsanders@ its.bldrdoc.gov

61 ITS is a recognized leader in radio Lockheed Martin Radar Measurement channel CRADA measurement and modeling whose Outputs resources and • Emission spectrum measurements of a new air-search radar. expertise are sought after both • Emission measurements of a new battlefield radar. by other • Seminars for LMCO on radar spectrum emissions. Government agencies and by he Institute makes its capabilities available and also delivered a seminar for LMCO on spec- private sector Tfor use with partners in the private sector trum management, spectrum emission criteria, companies. In via Cooperative Research and Development and spectrum measurement techniques. addition to Agreements (CRADAs); these agreements pro- Emission spectrum measurements were performing vide benefits for both the Government and the performed on a new air search radar system measurements, and private-sector partners. at Syracuse, NY, and other measurements were analyses on One CRADA completed in FY 2011 was with performed at a southwestern test and training request, ITS the Lockheed Martin Company (LMCO). Under range. The measurement results were analyzed engineers transfer this CRADA, ITS engineers performed emission- by ITS engineers and provided to the sponsor knowledge to spectrum measurements on new LMCO radars per the terms of the CRADA. others through training in spectrum measurement techniques developed over more than half a century of research.

Above: ITS engineers on the roof of an LMCO building during a radar emission spectrum measurement. Facing page, top: An ITS engineer during outdoor, nighttime measurements of an LMCO radar. Facing page, bottom: An LMCO radar measured under the ITS-LMCO CRADA. Photos by Frank Sanders

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For more information, contact: Frank Sanders (303) 497-7600 fsanders@ its.bldrdoc.gov

63 Maintaining public safety increasingly U.S. Navy Shore Line Intrusion depends on Monitoring System (SLiMS) Emissions sophisticated radio and radar Measurements equipment. New Outputs technologies for surveillance and • A full characterization of the emission characteristics of the SLiMS ultrawideband intrusion detection radar system promise more • A comprehensive study and model of interference potential of the SLiMS system to accurate and incumbent electronic systems (e.g., GPS and radar altimeters) at deployment locations detailed information for Overview set of emissions measurements on a shortened public safety The United States is currently engaged in a pole structure containing a single radar module. agencies, but global war on terror, and the security risks to In coordination with the Naval Surface Warfare before they can be U.S. personnel and assets have increased sig- Center (NSWC), ITS will: fully deployed • Ensure that the Navy system is compliant with testing, nificantly overseas and at home. The DOD is NTIA and FCC UWB emissions limits. measurement, and currently developing a number of surveillance • Ensure that the system does not constitute a analysis is needed radars to detect and identify intruders on the to ensure that they ground. In order for these systems to be de- hazard to either personnel or ordinance are both safe and ployed, they must be proved to be compatible • Perform an incumbent system study at SLiMS compatible with with incumbent electronics systems and not to deployment locations to make sure that inter- existing wireless pose safety hazards. ITS has a unique combi- ference does not occur devices. nation of expertise, equipment, and facilities to measure and evaluate these systems for Progress and Deliverables deployment. ITS engineers have completed a comprehensive series of emissions measurements on a Project Background SLiMS “short pole” in a fully anechoic chamber, The Navy Facilities Engineering Command as shown in the accompanying figure. An an- (NAVFAC) is sponsoring the development of an echoic chamber provides an interference-free ultrawideband (UWB) radar that can track as environment with high measurement precision. well as image intruders. It has been designated ITS measured antenna patterns, random losses, the Shore-Line Intrusion Monitoring System and peak/average radiated power levels. Emis- (SLiMS) system. The radar consists of a distrib- sion levels were measured over a frequency uted system of autonomous transmit/receive range of 1–15 GHz using a high-speed sampling modules mounted on poles, which are deployed around a facility to be protected. The number oscilloscope and precision spectrum analyzer. of poles and modules varies depending on the ITS conducted a series of antenna calibrations coverage needed. There are currently plans to in conjunction with the emissions measure- deploy this system at military bases in the con- ments to provide high precision and excellent tinental United States and in Alaska. The U.S. measurement fidelity. The data obtained will be Department of Energy (DOE) wants to deploy used in a comprehensive electromagnetic com- this system around a nuclear power plant. The patibility study at the SLiMS system deployment Navy has asked ITS to perform a comprehensive locations.

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A “short pole” mounted Shore-Line Intrusion Monitoring System (SLiMS) autonomous transmit module is set up in an anechoic chamber at the Department of Commerce Boulder Laboratories, with a receive antenna to capture and measure its emissions. Photo by Robert Achatz.

For more information contact: Robert J. Achatz (303) 497-3498 rachatz @its.bldrdoc.gov

65 Mobile video traffic surpassed 50% of Video Quality Research all mobile traffic in Outputs 2011,1 more than doubling for the • Improved techniques to measure video quality fourth year. Video • Development of software tools content has much • Distribution of test video higher bitrates than other mobile • Publication of technical papers content types; at • Representation of US interests in international standards bodies current bitrates, it is predicted that Overview the Video Quality Experts Group (VQEG, www. vqeg.org) and standardized by the prestigious monthly global here are three ways to measure video International Telecommunications Union (ITU). mobile data traffic quality: T In FY 2011, ITS completed development of will surpass 10 • Look at a test signal the most accurate model to date: the Video exabytes, or 70% of • Ask a person’s opinion of a video Quality Model with Variable Frame Delay mobile data traffic, • Use a computer algorithm (VQM_VFD). This new model includes a neural by 2016. Content Test signals were an effective way to measure network that was trained on people’s opinions providers video quality in the days of analog television. of the quality of 11,255 test videos in resolu- continuously For example, the camera focused on a picture tions ranging from cell phone size to HDTV. struggle to manage of wide and narrow lines. Video quality was the trade-offs measured by finding the narrowest line on a Consumer Digital Video Library between perceived television monitor. This does not work for mod- Finding—and getting rights to use—relevant video quality and ern digital systems. test video is an obstacle to some interesting bitrate through Asking a person’s opinion of video—also research topics. The Consumer Digital Video improved known as subjective testing—is by far the most Library Web site (CDVL, www.cdvl.org) was compression and accurate way to measure video quality. The cost created to address this problem. ITS developed, encoding and the time required are often a problem. For hosts, and supports the CDVL website. algorithms. To test example, industry needs rapid feedback while The CDVL makes high quality, uncompressed the effectiveness of fine tuning a new product, but subjective test- video clips available for download, free. Content these algorithms, ing is a lengthy and expensive process. owners can also upload and share their content. researchers and An objective video quality model is a com- Clips hosted on CDVL are ideal for use by the developers need puter algorithm that attempts to predict human education, research, and product development software tools that perception of video quality by trying to imitate communities. CDVL content is also useful to: can provide rapid human perception, object recognition and • Develop new products and economical judgment. This is difficult to do well. • Choose video equipment ways to measure • Improve video coding algorithms video quality. Reliable Objective Video • Optimize video system performance Quality Models • Train objective video quality models ITS has been developing objective Video • Conduct subjective video quality tests Quality Models (VQM) for over two decades. ITS’s VQM software offers an inexpensive alternative to subjective tests. The VQM software can be downloaded royalty-free for commercial or non-commercial use from www.its.bldrdoc. gov/vqm. In the last three years, 1245 people have downloaded the VQM software. The VQM software includes a variety of algorithms to suit different needs: the Peak Signal to Noise (PSNR) Model, the NTIA General Model, and the NTIA Fast Low Bandwidth Model HDTV camera used to film content for research 1. Cisco Visual Networking The PSNR Model has wide industry accep- and development. This camera lets ITS create Index: Global Mobile Data Traffic Forecast Update, tance but the two NTIA models offer improved broadcast quality videos, with the legal rights to 2011–2016, Feb. 2012. accuracy. All three models were evaluated by redistribute them. Photo by Andrew Catellier.

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Related Publication: G. Cermak, M. Pinson, S. Wolf, “The Relationship Among Video Quality, Screen Resolution, and Bit Rate,” IEEE Transactions on Broadcasting, vol. 57, no. 2, pp. 258–262, Jun. 2011 doi: 10.1109/ TBC.2011.2121650

Examples from the Consumer Digital Video Library (www.cdvl.org). This website encourages research and development into video topics. ITS hosts this library. Composition by William Ingram.

In FY 2011, 242 people downloaded video • Writing subjective test plans and reports from CDVL. Approximately 75 percent were Once an objective video quality model has from the U.S. and 25 percent from other coun- been tested by VQEG, the next step is an inter- tries around the world. About 75 percent of national standard. This provides reputable proof those who registered are from academia and that the algorithm is reliable. The video quality 25 percent from industry. ITS made 1000 video project supports video standardization efforts in clips available on CDVL in its first year (FY 2010) the Video Services Forum (www.videoservices- and another 1000 video clips in FY 2011. forum.org), ITU-T Study Group 9, ITU-T Study Group 12, and ITU-R Working Party 6C. Leadership ITS provides information to U.S. industry and VQEG determines whether objective video other Government agencies through responding quality models are accurate enough for industry to e-mail and phone inquiries, lab visits, technical to trust. ITS helped establish VQEG in 1997 and presentations, and publications. ITS sometimes For more continues to participate in VQEG by: performs subjective tests to answer questions information, • Co-chairing VQEG meetings raised during this exchange of information, as contact: • Providing independent oversight to promote reported in the related journal publication. Margaret H. Pinson fairness and accuracy More information can be found on the Video (303) 497 3579 • Analyzing data from VQEG sponsored subjec- Quality Research home page at http://www.its. mpinson tive tests bldrdoc.gov/n3/video. @its.bldrdoc.gov

67 Technology transfer is the Technology Transfer process by which Outputs existing knowledge, facilities, or • Collaborative research and development agreements capabilities • Technical papers and royalty-free data and software releases developed under • Collaborative standards contributions Federal research and development • Conferences, workshops and symposia (R&D) funding are TS is a member of the Federal Laboratory More recently, CRADAs in the areas of objective utilized to fulfill Consortium for Technology Transfer, the audio and video quality, advanced antennas public and private I nationwide network of federal laboratories or- for wireless systems, and remote sensing and needs. ganized to promote the fullest application and global position (GPS) technology have allowed Technology Transfer use of Federal research and development. Tech- ITS to contribute to the development of new Desk Reference, nology transfer aims to rapidly integrate Federal products and services. Federal Laboratory research outcomes into the mainstream of the CRADAs for Use of Table Mountain Consortium for U.S. economy to enhance U.S. competitiveness The Table Mountain Field Site is also made Technology Transfer in the global marketplace. Cooperative research available for telecommunications research to (FLC) and development agreements (CRADA), techni- other Government agencies and to private in- cal publications, and leadership and technical dustry through CRADAs. Access to this unique contributions in the development of telecom- resource particularly benefits small businesses, munications standards are the three principal who would otherwise be unable to perform means by which ITS transfers the fruits of our research that may be crucial to bringing a prod- research efforts to the private sector. uct to market. For more information on FY 2011 Cooperative Research and Table Mountain CRADAs, see page 16. Development Agreements Technical Publications In FY 2011, ITS participated—as it has for Historically, ITS has transferred research a number of years—in CRADAs with private- results to other researchers, the commercial sector organizations to design, develop, test, sector, and Government agencies through and evaluate advanced telecommunication con- publication of results either directly as NTIA cepts. CRADAs, authorized under the Federal publications or by submission of articles to Technology Transfer Act of 1986 (FTTA), allow peer-reviewed external scientific journals. Many ITS to enter into cooperative research agree- of these publications have become standard ments with private industry, universities, and references in several telecommunications areas. other interested parties that protect proprietary Technical publication remains a principal information, grant patent rights, and provide means of ITS technology transfer. An internal for user licenses to corporations. These part- peer review process managed by the ITS Edito- nerships aid in the commercialization of new rial Review Board (ERB) ensures quality of pub- products and services, as well as enhancing the lication. In FY 2011, ITS authors released eleven capabilities of ITS laboratories and providing re- NTIA Technical Reports, Memoranda or Hand- searchers with insights into industry’s needs for books through the ERB process and four journal productivity growth and competitiveness. This articles or conference papers, which underwent enables ITS to adjust the focus and direction of additional peer review outside ITS. A list of FY its programs for effectiveness and value, and to 2011 publications begins on page 76. undertake research in commercially important areas that it would not otherwise be able to do. Development of To date, major contributions to personal Telecommunication Standards communication services (PCS), local multipoint This method of technology transfer directly distribution service (LMDS), ultrawideband addresses improvement of U.S. competitiveness (UWB), and broadband over power line (BPL) in telecommunications. For several decades, ITS technologies have been achieved through CRA- has provided leadership and technical contribu- DAs. These have aided U.S. efforts to rapidly tions to national and international organizations introduce new communications technologies. responsible for developing telecommunication

68 Technology Transfer

standards. For example, a plurality of the tech- MHz frequency band (currently used by DOD nical recommendations of the International maritime radar systems). Telecommunication Union (ITU), a treaty or- ISART 2011 was designed to present a com- ganization, are based on research conducted prehensive evaluation of radar spectrum man- at ITS. Also, key national quality-of-service agement and usage. It provided a unique forum standards developed under the American Na- where prominent radar and telecommunica- tional Standards Institute (ANSI) T1 committee tions engineers from all countries and sectors for video, audio, and digital data incorporate could explore the interactions between these research results obtained at ITS. ITS chairs many distinctive technologies, contemplate enhanced committees and working groups in the ITU, spectrum engineering and sharing approaches, the Alliance for Telecommunications Industry and exchange information. Solutions (ATIS), and other telecommunication PSCR Technical Workshop standards organizations, providing technical ITS hosted the Public Safety Communications leadership that is trusted by commercial-sector Research (PSCR) Winter 2011 Technical Work- participants. ITS’s technical inputs are relied on shop on the topic of “Network Identifiers and as technically advanced, scientifically sound, Roaming/Clearing” November 30–December 1, and unbiased by commercial interests. 2011. This invitational workshop gathered In FY 2011, ITS continued its technical lead- representatives from the Public Safety Spectrum ership and contributions to communications Trust Operator Advisory Committee, PSCR’s 700 standards for public safety, particularly for first MHz Public Safety Broadband Demonstration responders. ITS’s primary area of contribution Network participants, and Federal partners to has been interoperability standards and testing share information and discuss issues surround- procedures. ITS’s objective video quality mea- ing Network Identifiers and Roaming/Clearing in the context of building out a nationwide, surement method has been made a national interoperable public safety broadband network. standard by ANSI. This method was also the best-performing metric in ITU comparison test- VQiPS ing with other methods from around the world. ITS hosted the 3rd annual Video Quality in Public Safety (VQiPS) conference and workshop Conferences, Workshops and February 16–18, 2011 in Boulder, CO. The meet- Symposia ing brought together practitioners, industry, ISART 2011 government and academia for the purpose of For over a decade, ITS has hosted the In- creating tools and standards to assist agencies in purchasing video equipment appropriate for ternational Symposium on Advanced Radio their applications. Technologies (ISART). This symposium brings together government, academia, and industry leaders from around the world for the purpose of forecasting the development and application of advanced radio technologies. The 12th Annual ISART was held at the De- partment of Commerce Laboratories in Boulder, Colorado, July 27–29, 2011. Its focus was “De- veloping Forward-Thinking Rules and Processes to Fully Exploit Spectrum Resources—Case Study 1: Radar.” Radar spectrum bands have The opportunity for extensive interaction For more frequently been identified as candidates for among participants is one of the most valuable information sharing, and important precedents have been aspects of ISART. Here, a representative of contact: set, such as FCC rules allowing 5 GHz U-NII private industry questions Commerce Assistant Brian D. Lane wireless networks that use Dynamic Frequency Secretary for Communications and Information (303) 497-3484 Selection (DFS) radar avoidance and NTIA fast- Larry Strickling during the extensive Q&A that blane track recommendations to share the 3550–3650 followed his Keynote Address. @its.bldrdoc.gov

69 FY 2011 Private Sector CRADAs Outputs

• Eight Cooperative Research and Development Agreements that allowed companies or universities to leverage Federal resources to bring product to market or complete research and development efforts faster and more safely

Areté Associates Boombang:

Laser Radar (LADAR) Testing on NWR Measurements Table Mountain Boombang is a venture incubator that as- Areté Associates is developing a variety of La- sists clients in multiple areas, including product ser Radar (LADAR) technologies for the U.S. De- engineering, design, and development. The partment of Defense. This CRADA allowed Areté company asked ITS to test the functionality of to use the Table Mountain Field Site as a field several prototype NOAA Weather Radio receiv- location to safely test and demonstrate these ers using simulated emergency broadcasts in technologies in atmospheric conditions and at order to identify strengths and weaknesses in distances relevant to potential applications. each as part of their product development cycle.

AUGNet is a project of the University of Colorado’s Research and Engineering Center for Un- manned Vehicles (RECUV), a university, government, and industry partnership for the development and application of unmanned vehicle systems. RECUV research encompasses scientific experiments, commercial applications, mitigation of natural and man-made disasters, security, and national defense. Pictured above is a flock of unmanned aircraft under test. Research on unmanned aircraft systems (UAS) includes work on mobile ad-hoc communications, delay-tolerant, ad-hoc protocols that allow UAS to operate in stressed or fractured networks. Cognitive radios being developed to support this research scan the RF spectrum to select frequencies with the best performance, behavior that has myriad applications for other communications systems. At right, a picture of the Tempest UAS. Tempest is an aerial robot system designed to perform in situ sampling of supercell thunderstorms, including those that produce tornadoes, and was a vital component of the VORTEX2 study to gather data on tornadoes that will be used to improve tornado forecasting. Photo above courtesy University of Colorado Boulder. Photo at right by Jack Elston.

70 Technology Transfer

Chaney Instrument Co. systems. This CRADA allowed FIRST RF to use the Table Mountain Field Site as a field location NWR Measurements to fully test the functionality of new antenna Chaney Instrument Co. designs and manu- designs as part of the product development factures NOAA Weather Radios. Cheney entered cycle. into two CRADAs with ITS during FY 2011 under which ITS performed functional testing of All Lockheed Martin/Coherent Hazards receivers using simulated emergency Technologies broadcasts. Cost-effective comprehensive test- Laser Radar (LIDAR) Testing ing is an integral part of the product develop- Lockheed Martin Coherent Technologies en- ment cycle for new or improved receivers. tered into a CRADA with ITS to engage in field- University of Colorado Boulder testing and characterization of components, subsystems, and systems for eyesafe coherent AdHoc UAV Ground Network (AUGNet) Test Bed laser radar at the Table Mountain Field Site. The The University of Colorado is experimenting instruments being tested use Light Detection with communication networks between low- and Ranging Systems (LIDAR), an advanced cost small unmanned aircraft (UA) similar to remote sensing technique that uses pulsed laser model radio-controlled airplanes and ground- light instead of radio waves (radar) to detect based radios. The networking is used to coor- particles and varying conditions in the atmo- dinate UAV activities and the goal is to develop sphere. The technology is used, among other autonomous “flocking” where the UAVs col- things, to improved flight safety by detecting lectively and autonomously complete sensing hazardous winds and aircraft wakes. and communication tasks. This project is part of Lockheed Martin the Ad hoc Ground Network (AUGNet) research activity which is part of the Research and Educa- Radar RSEC Measurements tion Center for Unmanned Vehicles (RECUV) at Lockheed Martin is developing a new deploy- the University of Colorado. This CRADA allowed able radar system designed to rapidly establish the university to use the Table Mountain Field airfield operations anywhere in the world for Site as a field location to safely and accurately both military and disaster relief efforts. Under test these technologies; test data and reports this CRADA, ITS was tasked with measuring were shared with ITS, providing ITS insights into the emission spectrum and related emission wireless network operations using commercial- characteristics of the two types of radar and to off-the-shelf (COTS) wireless LAN equipment. ascertain that both comply with the NTIA Radar Spectrum Engineering Criteria (RSEC) emission FIRST RF Corporation mask limits. This is critically needed data for Installed Performance of Antennas electromagnetic compatibility analyses between Under Test these radars and other radars with which they FIRST RF Corporation is a small business that will need to share spectrum. See more informa- designs and manufactures radio antennas and tion about this CRADA on page 62.

For more information contact: Brian D. Lane (303) 497-3484 blane @its.bldrdoc.gov

71 Technical standards formally ITU-R Standards Activities document common Outputs norms or requirements for • Technical support for U.S. Administration activities in ITU-R Study Group 3 and technical systems. Working Parties 1A, 3J, 3K, 3L, 3M, 5B, 5D, and 6C Establishing • Leadership roles in U.S. Study Group 3, U.S. Working Party 3K, U.S. Working Party 3J uniform • Development of a new version of ITU-R Recommendation SM.1541, Unwanted engineering or Emissions in the Out-of-Band Domain technical criteria, methods, • Development of a new version of ITU-R Recommendation P.528, Propagation Curves processes, and for Aeronautical, Mobile and Radionavigation Services using the VHF, UHF and SHF practices for Bands telecommunica Overview multimedia, and data services principally in- tions helps to The International Telecommunications Union tended for delivery to the general public. overcome technical - Radiocommunication Sector (ITU-R) is the barriers in Participation in Study Group 1 authoritative international organization for the international trade, In FY 2011 the Institute supported the U.S. standardization, coordination, and regulation minimize Administration on radar issues in ITU-R WP 1A. of the radio frequency spectrum. It is the single interference, and (Figure 1) The critical issue that had to be ad- most important worldwide telecommunications maximize dressed this year was out-of-band (OOB) limits interoperability. regulatory and standardization body. Within the on radar transmissions. ITU-R Recommenda- ITU-R ITU-R, Study Groups (SG) are responsible for the tion SM.1541 contains an annex that governs international development and maintenance of Questions, the characteristics of these emissions. The U.S. technical Recommendations, Reports, and Handbooks, as Administration seeks consistency between the standards, called well as undertaking studies assigned to them as SM.1541 OOB limits and the domestic limits of Recommendations, a result of decisions by World Radiocommuni- the Radar Spectrum Engineering Criteria (RSEC). are developed by cation Conferences. Within the Study Groups, This ensures that systems that meet the domes- small Working Working Parties (WP) are set up as needed to tic limits also comply with international limits. Parties, finalized by study specific Questions assigned to them. ITS Such consistency is especially important for the larger Study provides ongoing technical support to the U.S. Department of Defense radar operations within Groups, and Administration in ITU-R Study Groups 1, 3, 5 and close to the edges of other administration’s approved by the and 6 and their Working Parties; in particular, territories (e.g., Air Force and Navy radar opera- 193 member states. Working Parties 1A, 3J, 3K, 3L, 3M, 5B, 5D, and tions around Europe, the Middle East and the Though not 6C. Study Group 1 deals with spectrum man- Far East). In preparation for the WP 1A meeting, mandatory, in agement, sharing, monitoring, and utilization. ITS engineers performed a series of measure- practice ITU-R Study Group 3 deals with radio propagation ments in the field to document actual emissions Recommendations phenomena. Study Group 5 deals with systems from the relevant radars (Figures 2 and 3). In are implemented and networks for fixed, mobile, radiodetermi- a series of negotiations in Geneva, especially worldwide. nation, amateur and amateur-satellite services. with Japan, Germany, and the UK, ITS engineers Study Group 6 deals with radiocommunica- obtained agreement on a revised version of tion broadcasting, including vision, sound, SM.1541 that sets the same limits on OOB radar emissions as the existing US RSEC. This was an important milestone in the continuing effort to allow U.S. radars to support critical national security operations internationally.

Figure 1. ITU-R WP-1A plenary meeting in Ge- neva, Switzerland in May 2011. Photo by Frank Sanders.

72 Technology Transfer

ITS engineers performed measurements on a Navy Sea Sparrow radar (Figure 2, left) and a Relocatable Over the Horizon Radar (ROTHR) (Figure 3, below) to determine actual emission bandwidths of representative Navy frequency-modulated continuous- wave (FMCW) radars. The measurement results shaped the U.S. Contribution to the May 2011 ITU-R Working Party 1A meeting. Photos by Frank Sanders. Participation in Study Group 3 ITS engineers play important roles in SG 3 and in all four of the ITU-R SG 3 Work- ing Parties: WP 3J (Propaga- tion Fundamentals), WP 3K (Point-to-Area Propagation), WP 3L (Ionospheric Propaga- tion) and WP 3M (Earth-Space and Point-to-Point Propaga- tion). ITS engineers currently serve as the International Chair of WP 3K, the third served as Chair of the Drafting Group and U.S. Chair of SG3, the Chair of Correspondence Rapporteur of the Correspondence Group re- Group 3K-3, and the Head of Delegation (of- sponsible for preparing a major revision of Rec- ficial spokesperson) for the U.S. Administration ommendation ITU-R P.528 (Propagation Curves at meetings of ITU-R Study Group 3 and all of for Aeronautical, Mobile and Radionavigation its Working Parties. Services using the VHF, UHF and SHF Bands). The international block meetings of ITU-R Working Parties 3J, 3K, 3L, and 3M took place Participation in Study Group 5 in October 2011 at the ITU Headquarters in Ge- An ITS engineer has provided technical sup- neva, Switzerland. The meeting of ITU-R Study port and participated as a member of the U.S. Group 3 took place immediately following the Delegation in national and international meet- block meetings of the Working Parties, at the ings of Working Party 5D during the current same venue. In accordance with State Depart- Study Period, 2008–2012 (see “Interference ment rules, U.S. Study Group 3 held monthly Issues Affecting Land Mobile Systems” on page preparatory meetings from late May 2011 to 34). As part of this work, this ITS engineer review and comment on proposed U.S. Admin- also participated in other U.S. national stan- istration contributions to these meetings. Four dards bodies (e.g., ATIS). ITS engineers participated in the U.S. preparatory meetings. An ITS engineer chaired the U.S. Participation in Study Group 6 preparatory meetings. An ITS staff member serves as the ITU-R For more Three ITS engineers served as members of WP6C Rapporteur for global video evaluation information the U.S. delegation to the meetings of ITU-R methodology landscape. The purpose of this contact: Study Group 3 and its Working Parties. One of position is to harmonize video quality activi- Paul M. McKenna these engineers served as acting Chair of ITU-R ties among the ITU-T and ITU-R Study Groups (303) 497-3474 Working Party 3K during its meetings, a second working in the area of video/multimedia quality pmckenna served as Head of the U.S. Delegation, while a assessment. @its.bldrdoc.gov

73 The ITU exists to provide a neutral ITU-T and Related U.S. Standards platform for Development shaping global consensus on the Outputs standards that • Leadership of ITU-T and related telecommunications committees enable a seamless robust, and • Technical contributions presenting U.S. standards proposals and ITS research results reliable, global • Proposed ITU-T Recommendations and associated U.S. industry standards communications system. Developing Overview ITU-T Study Group 9 and influencing he Institute has a long history of leadership, ITU-T Study Group 9 carries out studies on international Ttechnical contributions, and advocacy of the use of telecommunication systems for standards and U.S. Government and industry proposals in the broadcasting of television and sound programs policies supports International Telecommunication Union’s Tele- and the use of cable television networks to pro- the full and fair communication Standardization Sector (ITU ‑T) vide interactive video services, telephone, and competitiveness of and related U.S. standards organizations. ITU-T data services, including Internet access. Among the U.S. is a specialized agency of the United Nations, re- the Recommendations standardized by ITU-T information and sponsible for developing the international stan- SG9 are those defining video and multimedia communications dards (Recommendations) that providers use to quality assessment and those supporting Emer- technology sector. plan, interconnect, and operate public telecom- gency Telecommunications over broadband ITS plays a vital munication networks and services worldwide. cable networks. role in representing ITU-T Recommendations strongly impact both While this project provides input to the Alli- the interests of the evolution of U.S. telecommunication infra- ance for Telecommunications Industry Solutions U.S. industry and structures and the competitiveness of U.S. tele- (ATIS), the Society of Cable Telecommunications the U.S. communication products in international trade. Engineers (SCTE), and the ITU-R, the majority of Administration to The Institute’s long-term goal in ITU-T (and work is directed to ITU-T SG9 and VQEG. In FY the ITU-T as it related national standards work) is to motivate 2011, Arthur Webster served as international produces or revises the standardization of user-oriented, technol- Chair of ITU-T SG9 (Figure 1), which is responsi- over 150 ogy-independent measures of telecommunica- ble for broadband cable networks and television information and tion service quality, and to relate those measures and sound transmission. Margaret Pinson co- communications to the technology-specific performance metrics chaired Question 12/9 (Objective and Subjective technology and mechanisms providers use to provision Methods for Evaluating Audiovisual Quality in standards each and operate networks. This work promotes Multimedia Services) and served as Head of the year. fair competition and technology innovation U.S. Delegation to ITU-T SG9 (Figure 2). in the telecommunications industry, facilitates inter-working among independently-operated VQEG networks and dissimilar technologies, and helps An ITS staff member founded the Video users define their telecommunication needs and Quality Experts Group and has co-chaired it select products and services to best meet them. since 1997. VQEG enables video experts from One way ITS promotes telecommunications many countries to collaborate in developing standardization efforts is by accepting leader- and evaluating video quality metrics (VQM). ship roles in key standards development orga- The group’s reports strongly impact the stan- nizations. In FY 2011, Institute staff members dardization of VQMs in both ITU-T and ITU-R. held several prestigious leadership roles includ- VQEG works largely via several e-mail reflectors, ing Chair of ITU-T Study Group (SG) 9 (Televi- publicly accessible at http://www.VQEG.org. sion and sound transmission and integrated During FY 2011, the number of participants broadband cable networks), Co-Chair of the subscribed to the main reflector grew to over ITU Video Quality Experts Group (VQEG), and 650. VQEG produces independent validation Co-Chair of the Joint Rapporteur Group on Mul- data, which the U.S. considers to be a key pre- timedia Quality Assessment (JRG-MMQA). An requisite for standardizing a VQM. Thus, VQEG ITS staff member served as Co-Chair of VQEG’s acts as a cooperative technical advisory com- high-definition television (HDTV) Group and led mittee that facilitates standardization efforts in the group’s technical work to completion. ITU-T SG9, SG12 (Performance and Quality of

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Figure 1 (left). Arthur Webster Chairing the ITU-T SG9 meeting in Geneva. Figure 2 (middle). Margaret Pinson led the U.S. delegation to the ITU-T SG9 meeting in Geneva.

Figure 3 (below). VQEG Meeting in Atlanta, November 2010.

Service (QoS)), and ITU-R Work- ing Party (WP) 6C (Broadcasting Services—Programme Produc- tion and Quality Assessment) to develop objective, computer implementable, perception-based video and multimedia quality metrics that emulate the human visual system. ITS staff members provide key leadership and technical contributions to VQEG. Arthur Webster co-chaired VQEG and chaired the two meetings that occurred in FY 2011 (Figure 3). Margaret Pinson co-chaired the HDTV effort and is now spearheading the next testing effort for HDTV. The completion of the first HDTV test led to the approval in SG9 of two New Recommendations. ITS also assisted in developing the Hybrid Perceptional Bit-Stream video test plan. meets concurrently with VQEG. The JRG-MMQA Through the combined efforts of this and other provides an official mechanism for coordinating ITS projects, the Institute provided key video VQEG activities with ITU-T SG9 and ITU-T SG12. source material that comprises most of the vali- Approved Recommendations dation sequences used in the HDTV effort. ITS is spearheading new ITU-T work on audiovisual FY 2010 saw the completion of VQEG’s quality assessment through its leadership in HDTV Project. The results of this validation VQEG. test were reported to the ITU, and in FY 2011, ITU-T SG9, under the Chairmanship of Arthur JRG-MMQA Webster, approved two new Recommendations In related work, ITS leads the ITU-T’s Joint based on VQEG’s test results: Rapporteur Group on Multimedia Quality As- • Recommendation ITU-T J.341 (01/11), Objec- sessment (JRG-MMQA). This is a cross-cutting tive perceptual multimedia video quality mea- For more ITU-T standards body that unites the video surement of HDTV for digital cable television information quality expertise of SG9 with the audio and in the presence of a full reference. contact: network quality expertise of SG12 in an effort • Recommendation J.342 (04/11), Objective Arthur A. Webster to develop objective, perception-based metrics perceptual multimedia video quality measure- (303) 497-3567 for combined audio and video signals in mobile ment of HDTV for digital cable television in the awebster and PC environments. The JRG-MMQA typically presence of a reduced reference. @ its.bldrdoc.gov

75 At the IEEE- sponsored Third ITS Publications and Presentations in International FY 2011 Workshop on Quality of NTIA Publications quality for synchronized video or investigated Multimedia John E. Carroll, Frank H. Sanders, Robert L. the quality impact of synchronization errors on Experience Sole, and Geoffrey A. Sanders, “Case Study: unimpaired video sequences. This experiment is a first attempt to combine all three factors (QoMEX 2011) in Investigation of Interference into 5 GHz into a single experiment, to judge the complex Mechelen, Belgium Weather Radars from Unlicensed National interactions among individual measurements September 7–9, Information Infrastructure Devices, Part I,” of audio and video quality and synchronization 2011, leading NTIA Technical Report TR-11-473, November errors. experts from 2010 academia and In early 2009, the Federal Aviation Admin- Stephen Wolf, “Variable Frame Delay (VFD) industry presented istration (FAA) became aware of interference Parameters for Video Quality Measure- the latest to Terminal Doppler Weather Radars (TDWRs) ments,” NTIA Technical Memorandum TM- developments on that operate in the 5600–5650 MHz band 11-475, April 2011 evaluation of and provide quantitative measurements of Digital video transmission systems consist- multimedia quality gust fronts, windshear, microbursts, and other ing of a video encoder, a digital transmission based on user weather hazards for improved safety of opera- method (e.g., Internet Protocol—IP), and a video experience. The 36 tions in and around major airports. This report decoder can produce pauses in the video pre- presented papers describes field measurements and results from sentation, after which the video may continue included six an examination of interference to a TDWR in with or without skipping video frames. Some- references to NTIA/ San Juan, Puerto Rico from unlicensed national times sections of the original video stream may ITS authored information infrastructure (U–NII) dynamic be missing entirely (skipping without pausing). papers, nine frequency selection (DFS) devices operating in Time varying delays of the output (or processed) references to Video the same frequency band. Several U–NII devices video frames with respect to the input (i.e., the Quality Experts from different manufacturers were found to be original or reference) video frames present sig- Group (VQEG) causing interference into the TDWR. These de- nificant challenges for Full Reference (FR) video documents, and 17 vices operate in the same bands as these Federal quality measurement systems. Time alignment references to ITU-T radar systems, but employ DFS technology that errors between the output video sequence and Recommendations is supposed to detect the presence of nearby ra- the input video sequence can produce measure- produced by ITS dar systems and change operating frequencies ment errors that greatly exceed the perceptual Rapporteurs to prevent interference with incumbent radar impact of these time varying video delays. This systems. This is the first of a three–part series document proposes several objective video of reports that describe research efforts by the quality parameters that can be extracted from Institute for Telecommunication Sciences (ITS) variable frame delay (VFD) information, demon- engineers, with assistance from FAA engineers, strates their correlation to subjective video qual- to determine the cause of the interference, un- ity, and shows how they can be utilized in an FR derstand why some devices fail to detect TDWR video quality measurement (VQM) system. signals, and engineer solutions. Peter Papazian and John Lemmon, “Radio Margaret H. Pinson, Arthur Webster and Wil- Channel Impulse Response Measurement and liam Ingram, “Preliminary Investigation into Analysis,” NTIA Technical Report TR-11-476, the Impact of Audiovisual Synchronization of May 2011 Impaired Audiovisual Sequences,” NTIA Tech- This paper describes radio channel sounding nical Memo TM-11-474, March 2011 measurements and analysis using pseudo-noise The quality perception of an audiovisual (PN) codes. It presents a channel sounding model sequence is heavily influenced by the quality and shows how channel measurements can of the audio, the quality of the video, and the be made. A measurement system is described audiovisual time synchronization. The questions that can be implemented using a combination then arise: what is the relative importance of of radio frequency (RF) hardware, high-speed each factor, and can a model be devised that is analog to digital converters (ADC), and signal generally applicable? Previous work either exam- processing software. Sampling requirements ined the relative influences of audio and video and models for describing the stochastic nature

76 Technology Transfer

of the radio channel are discussed. Typical signal conventional fading assumptions to provide outputs of a PN channel sounder from the labo- an independent theoretical understanding of ratory and from field measurements are shown. RF fading propagation. Finally, an assessment The field measurements are used to show of the efficacy of classical fading theory in the how channel sounding data can be processed testing of existing public safety VHF transceiv- to develop a power law model of short-range ers is discussed with conjectures about future communications. This model can be used for transceiver testing and design. a statistical estimation of received power and Gregory Cermak, Margaret H. Pinson, and interference analysis. Stephen Wolf, “The Relationship Among Chris Redding, Chris Behm, Tim Riley, and Rob Video Quality, Screen Resolution, and Bit Stafford, “Examining the Validity of Rayleigh Rate,” IEEE Transactions on Broadcasting, Distribution Assumptions in Characterizing vol.57, no.2, pp. 258-262, June 2011 the Fading Channel at 162 and 793 MHz,” How much bandwidth is required for good NTIA Technical Memorandum TM-11-477, quality video for a given screen resolution? June 2011 Data acquired during two Video Quality Experts Wireless communications experience tem- Group (VQEG) projects allow at least a partial poral variations in received signal level that answer to this question. This international sub- are characteristic of the propagation channel. jective testing produced large amounts of mean Propagation channel fading at VHF and above opinion score (MOS) data for the screen reso- is predominantly caused by the complex scat- lutions QIF, CIF, VGA, and HD; for H.264 and tering environment through which the radio similar modern codecs; and for many bit rates. waves travel. The techniques used in receiver Those data are assembled in the present report. For each screen resolution, MOS is plotted as design to mitigate the effects of fading are a function of bit rate. A plot of all four data well established, but the constraints of limited sets together shows the bit rate that would be spectral resources and the insidious character- required to achieve a given level of video quality istics of the propagation environment demand for a given screen resolution. Relations among increasingly complex modulation techniques the four data sets are regular, suggesting that to accomplish this mitigation. To maintain interpolation across screen resolutions might be system reliability and usability, receivers must reasonable. Based on these data, it would be be built to increasingly higher tolerances to reasonable to choose a bit rate, given a screen cope with propagation-induced errors. This resolution; it would not be reasonable to choose report describes a re-examination of the fading a screen resolution given a bit rate. channel. Specifically, it presents a reassessment of the assumptions implicit in the understand- Jeffery A. Wepman and Geoffrey A. Sanders, ing of fading channels. This effort involves the “Wideband Man-Made Radio Noise Measure- measurement, analysis, and assessment of ments in the VHF and Low UHF Bands,” NTIA propagation fading and describes the limita- Technical Report TR-11-478, July 2011 tions of classical fading theories when applied Man-made radio noise measurements were to ever more sophisticated modulation tech- conducted in a 1.16-MHz bandwidth at 112.5, niques. The ultimate purpose of this report is 221.5, and 401 MHz at two residential and to investigate the statistical fading behavior of two business locations in the Boulder/Denver, the radio channel within time frames significant Colorado, area. The measurement frequencies to the reception of digitally-modulated signals. and bandwidth were selected using the re- Measurements of the mobile radio channel sults of a spectrum survey performed over the were conducted to analyze the fast fading char- 104– 1060-MHz frequency range. The noise acteristics of the public safety frequency band. measurement data were collected as a complex The measurement system is described, as are baseband noise data record (consisting of six improvements made to increase its capability million in-phase (I) and quadrature-phase (Q) to measure the channel characteristics. Data samples) every 10 minutes over a 24-hour pe- analysis was conducted without bias toward riod for each frequency and location. The data

77 were processed to provide various statistical de- and around major airports. Institute for Tele- scriptions of the noise such as amplitude prob- communication Sciences (ITS) engineers, with ability distributions (APDs). Median values of the assistance from FAA engineers, determined antenna noise figure Fam were determined for the interference to be from unlicensed national each measurement frequency and environment information infrastructure (U-NII) dynamic type and compared to predicted values from frequency selection (DFS) devices, from several existing man-made radio noise models. The manufacturers, operating in the same frequency measured values of Fam, while larger than the band as TDWR systems. These devices operate in values predicted by the International Telecom- the same bands as these Federal radar systems, munication Union (ITU) man-made radio noise but employ DFS technology that is supposed model, were still within one standard deviation to detect the presence of nearby radar systems of the predicted values. Further noise measure- and change operating frequencies to prevent ments are recommended in a greater number of interference with incumbent radar systems. This locations to provide more statistically significant report describes measurements and results from results. controlled laboratory and field testing of these U-NII devices. This is the second of a three-part John E. Carroll, Geoffrey A. Sanders, Frank series of reports that describe research efforts H. Sanders, and Robert L. Sole, “Case Study: by the ITS engineers, with assistance from FAA Investigation of Interference into 5 GHz engineers, to determine the cause of the inter- Weather Radars from Unlicensed National ference, examine the effects of the interference Information Infrastructure Devices, Part II,” on TDWR systems, and engineer solutions. NTIA Technical Report TR-11-479, July 2011 In early 2009, the Federal Aviation Adminis- Eric D. Nelson and Nicholas DeMinco, “Im- tration (FAA) became aware of interference to proved Estimation of the Third-Order Har- Terminal Doppler Weather Radars (TDWRs) that monic Emissions of Land Mobile Radio Base operate in the 5600–5650 MHz band and pro- Stations,” NTIA Technical Report TR-11-481, vide quantitative measurements of gust fronts, September 2011 windshear, microbursts, and other weather NTIA/ITS has developed an improved electro- hazards for improved safety of operations in magnetic 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 analyses for base stations that use a variety of antennas. The model can be used to determine the received power in the proximity of the base station at both the fundamental and harmonic frequencies. It uses accurate radio-wave propagation models and antenna models. The antenna models can be created for the fundamental and third harmonic frequencies of many antennas. Fields

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adjacent to the base station antenna are heav- technology, problems endemic to it, and solu- ily influenced by interactions with ground, and tions to these problems. Appendices provide the electromagnetic fields are dominated by the detailed data tables, theory, calculations, and side lobe structure of the elevation pattern of measurements that support assertions made in the base station antenna. The described rigor- the main body. ous EMC analysis for a base station considers all of these factors to assess interference more Margaret H. Pinson and Stephen Wolf, “Batch accurately than previous methods. Video Quality Metric (BVQM) User’s Manual,” NTIA Handbook HB-11-441d, September Stephen Wolf and Margaret H. Pinson, “Video 2011 Quality Model for Variable Frame Delay This handbook provides a user’s manual for (VQM_VFD),” NTIA Technical Memorandum the batch video quality metric (BVQM) tool. TM-11-482, September 2011 BVQM runs under the Windows XP® or Win- Time varying delays of the output (or pro- dows 7® operating systems. BVQM performs cessed) video frames with respect to the input objective automated quality assessments of (i.e., the original or reference) video frames pres- processed video clip batches (i.e., as output ent significant challenges for Full Reference (FR) by a video system under test). BVQM reports video quality measurement systems. Time align- video calibration and quality metric results such ment errors between the output video sequence as: temporal registration, spatial registration, and the input video sequence can produce spatial scaling, valid region, gain/level offset, measurement errors that greatly exceed the and objective video quality estimates. BVQM perceptual impact of these time varying video operates on original and processed video files delays. This document proposes a new video only, and has no video capture capability. BVQM quality model (VQM) that properly accounts for compares the original video clip to the pro- the perceptual impact of variable frame delay cessed video clip and reports quality estimates (VFD). This new model, called VQM_VFD, also on a scale from zero to one. On this scale, uses perceptual features extracted from spatial- zero means that no impairment is visible and temporal (ST) blocks of a fixed angular extent. one means that the video clip has reached the This enables VQM_VFD to track subjective qual- maximum impairment level (excursions beyond ity over a wide range of viewing distances and one are possible for extremely impaired video image sizes. VQM_VFD uses a neural network sequences). that achieves 0.9 correlation to subjective quality for subjective datasets at image sizes from Journal Articles and Quarter Common Intermediate Format (QCIF) to Conference Papers High Definition TV (HDTV). Stephen D. Voran and Andrew A. Catellier, Robert J. Achatz, Roger A. Dalke and John J. “Multiple Description Speech Coding Using Lemmon, “In-Building Radio Enhancement Speech Polarity Decomposition,” Proceedings Systems for Public Safety,” NTIA Technical of the IEEE Global Communications Confer- Report TR-11-480, September 2011 ence (GLOBECOM 2010), pp.1-6, Miami, FL, Reliable public safety communications December 6-10, 2010 between system repeaters outside a building We present and evaluate a new multiple–de- and portable radios inside a building is often scription coding extension to the international not possible due to building attenuation. To standard for pulse code modulation speech circumvent this problem, increasing numbers of coding (ITU–T Rec. G.711). This extension is municipalities are requiring building owners to inserted between the G.711 encoder and de- provide in-building radio enhancement systems coder. It uses speech–polarity decomposition to (IBRESs) for public safety communications. This spread the speech signal across two channels report is intended to be used by public safety thus increasing robustness to channel losses. communications professionals who are tasked When both channels deliver their payloads the with assisting building owners to fulfill this extension becomes transparent and bit–exact requirement. The main body describes IBRES G.711 speech samples are produced—there is

79 no quality penalty. Due to low inter–channel visual intelligibility in video—a user’s ability to redundancy, block coding, and entropy coding, recognize an object in a video stream given the average total speech payload bit–rate is no various conditions. The test sought to measure greater than the 64 kbps rate of conventional the effects on visual intelligibility of three scene G.711—there is no rate penalty. When either parameters (target size, scene motion, scene channel fails to deliver, the remaining channel lighting), several compression rates, and two still produces intelligible speech with moder- resolutions (VGA (640x480) and CIF (352x288)). ately reduced quality thanks to a compressed Seven similarly sized objects were used as tar- sine–pulse fill–in algorithm. We are not aware gets in nine sets of near-identical source scenes, of any other viable multiple–description coding where each set was created using a different extension that simultaneously meets the op- combination of the parameters under study. posing goals of no quality penalty and no rate Viewers were asked to identify the objects via penalty. multiple choice questions. Objective measurements were performed on each of the scenes, Joel Dumke, Carolyn G. Ford, and Irena W. and the ability of the measurement to predict Stange, “The effects of scene characteristics, visual intelligibility was studied. resolution, and compression on the ability to recognize objects in video,” Proceedings of Stephen D. Voran and Andrew A. Catel- SPIE 7865, 78650P, San Francisco, CA, Janu- lier, Gradient Ascent Subjective Multimedia ary 24–27, 2011 Quality Testing, EURASIP Journal on Image Public safety practitioners increasingly use and Video Processing, vol. 2011, Article ID video for object recognition tasks. These end 472185, 14 pages, March 15, 2011 users need guidance regarding how to identify Subjective testing is the most direct means the level of video quality necessary for their of assessing multimedia quality as experienced application. The quality of video used in public by users. When multiple dimensions must be safety applications must be evaluated in terms evaluated, these tests can become slow and costly.We present gradient ascent subjective of its usability for specific tasks performed by testing (GAST) as an efficient way to locate the end user. optimizing sets of coding or transmission pa- The Public Safety Communication Research rameter values. GAST combines gradient ascent (PSCR) project performed a subjective test as optimization techniques with subjective test one of the first in a series to explore trials. As a proof-of-concept, we used GAST to search a two-dimensional parameter space for the known region of maximal audio quality, using paired-comparison listening trials. That region was located accurately and much more efficiently than use of an exhaustive search. We also used GAST to search a two- dimensional quantizer design space for a point of maximal image quality, using side-by-side paired-comparison trials. The point of maximal image quality was efficiently located, and the corresponding quantizer shape and deadzone agree closely with the quantizer specifications for JPEG 2000, Part 1.

Mikolaj I. Leszczuk, Irena Stange and Carolyn Ford, “Determining Image Quality Require- ments for Recognition Tasks in Generalized Public Safety Video Applications: Defini- tions, Testing, Standardization, and Current Trends,” Proceedings of the IEEE International

80 Technology Transfer

Symposium on Broadband Multimedia Sys- • C. Redding, “Empirical Studies of Fading tems and Broadcasting, Nuremberg, June Channel Characteristics at VHF and UHF Fre- 8–10, 2011 quencies,” presented at the 2011 USNC-URSI The Quality of Experience (QoE) concept for National Radio Science Meeting, Boulder, CO, video content used for entertainment differs January 5–8, 2011. materially from the QoE of video used for pub- • J. Dumke and C. Ford, “The Effects of Scene lic safety tasks because in the latter case, the Characteristics, Resolution, and Compression subjective satisfaction of the user depends upon on the Ability to Recognize Objects in Video,” achieving the given task. Yet currently there are presented at the SPIE Electronic Imaging Con- hardly any quality standards for task-based ference, San Francisco, CA, January 23–27, video applications. This is an important problem 2011. as the transmission and analysis of video is used • J. Bratcher and E. Olbrich (NIST), “Public Safety for many applications outside the entertain- 700 MHz Broadband Demonstration Net- ment sector, and generally this class of video work,” an invited presentation at the GSMA is used in the performance of a specific task. Mobile World Congress, Barcelona, Spain, To address this lack, in this paper we introduce February 14–18, 2011. new methods of assessing video quality for • DJ Atkinson, “PSCR Audio Testing Update,” task-based video that have been under develop- presented at the International Wireless Com- ment. Once a framework and measurement sys- munications Exposition (IWCE), Las Vegas, NV, tem have been developed for task-based video, March 7–10, 2011. performance specifications and standards can • A. Thiessen and D. Orr (NIST), “P25 Compliance be developed to assist users of task-based video Assessment Program Overview,” presented at to identify the technology that will allow them the International Wireless Communications to successfully perform the required function. Expo (IWCE) College of Technology, Las Vegas, Unpublished Presentations NV, March 7–10, 2011 • A. Webster, “Introduction to International • M.H. Pinson, “The Consumer Digital Video Li- Telecommunication Union (ITU) Telecom- brary,” presented at the Video Services Forum meeting, Austin, TX, October 5–8, 2011. munication Standardization Sector (ITU-T),” • R. Johnk and J. Ewan, “High-resolution presented at the Telecommunications Industry propagation measurements using biconical Association (TIA) Global Standards Collabora- antennas and signal processing,” presented tion (GSC) Machine-to-Machine Standardiza- at the General Meeting of the International tion Task Force (MSTF) Meeting, Dallas, TX, Electrotechnical Commission (IEC) in Seattle, May 18, 2011. WA, October 6–15, 2010 • J. Carroll, F. Sanders, R. Sole, “Case Study: • R. Johnk and P. McKenna, “Fully-anechoic Investigation of Interference into 5-GHz chamber performance metrics,” presented at Weather Radars from Unlicensed Wireless De- the General Meeting of the International Elec- vices,” presented at the 2011 Tri-Service Radar trotechnical Commission (IEC) in Seattle, WA, Symposium Spectrum Workshop, Monterey, October 6–15, 2010 CA, June 27–30, 2011. • T. Riley, “A Co-Channel Interference Model for • J. Bratcher and E. Olbrich (NIST), “Public For information Safety Broadband Demonstration Network,” Spread Spectrum Technologies,” presented at about ITS presented at the APCO International 77th An- the 2011 USNC-URSI National Radio Science publications Meeting, Boulder, CO, Jan 5–8, 2011. nual Conference and Expo, Philadelphia, PA, contact: • J. Carroll, “Case Study: Investigation of In- August 7–10, 2011. Lilli Segre, terference into 5 GHz Weather Radars from • B. Johnk, “Time-domain Anechoic Chamber Publications Unlicensed National Information Infrastruc- Performance Metrics,” presented at the 2011 Officer ture (U-NII) Devices,” presented at the 2011 IEEE International Symposium on Electromag- (303) 497-3572 USNC-URSI National Radio Science Meeting, netic Compatibility (EMC 2011), Long Beach, lsegre Boulder, CO, January 5–8, 2011. CA, August 14–18, 2011. @its.bldrdoc.gov

81 ITS research and technical ITS Standards Leadership and contributions Contributions based on that research support Representative Leadership Roles held by ITS Staff U.S. • International Chairs of one ITU-R Working Party, one ITU-R Subgroup and one ITU-T Administration Study Group positions in standards-setting • U.S. Chairs of one ITU-R Study Group and three Working Parties bodies. Timely • Chairs of two ITU-R Correspondence Groups promulgation of • Head of U.S. Delegation to ITU-T Study Group new standards for emerging • Chair of NPSTC Working Group technologies is • Chair of TIA Working Group important for many reasons. Standards ational and international standards and and Personal Private Radio Standards Engi- for public safety Npolicies for telecommunications support neering Committee. communications the full and fair competitiveness of the U.S. • Christopher J. Behm: U.S. Chair of Interna- equipment impact information and communications technology tional Telecommunication Union Radiocom- both the safety and sectors. Technical standards establish communication Sector (ITU-R) Study Group 3 effectiveness of mon norms for technical systems—uniform (Radiowave Propagation), Head of Delegation public safety engineering or technical criteria, methods, for Working Party 3L and delegate to WP 3L practitioners by processes and practices that promote competi- and WP 3K. promoting tion and interoperability. Office of Management • Randall S. Bloomfield: Technical participant increased and Budget Circular A-119 (February 10, 1998) and voting representative for NIST/OLES in interoperability promotes the use of voluntary consensus stan- TIA Engineering Committee TR-8 (Mobile and and intelligibility of dards in order to “encourage long-term growth Personal Private Radio Standards) and APIC; communications. A for U.S. enterprises and promote efficiency and Editor of the P25 SoR (Project 25 Statement of published body of economic competition through harmonization Requirements) in the P25 UNS (Project 25 User applicable of standards” and encourages the participation Needs Subcommittee). standards gives of authorized Federal agency representatives in • John E. Carroll: Delegate to ITU-R Working industry the standards activities. Party 5B. confidence to • Paul M. McKenna: International Chair of ITU- invest by FY 2011 Standards Activities R Working Party 3K, U.S. Chair of 3J, 3L, and broadening the Standards Leadership 3M; International Chair of Subgroup 3K-2. market and As representatives of the U.S. Administra- decreasing the • Margaret H. Pinson: Associate Rapporteur limitations tion, ITS staff advocate globally standards and for Question 12/9 (Objective and subjective inherent in legacy policies that encourage competition and inno- methods for evaluating perceptual audiovi- systems. vation in communications technology through sual quality in multimedia services within the leadership roles and membership in standards terms of Study Group 9) in ITU-T Study Group development organizations. In cooperation 9 (Integrated broadband cable networks and with other interested U.S. Government agen- television and sound transmission); ITU-T cies and industry groups, ITS staff organize and Study Group 9 contact for Electronic Working coordinate preparations for U.S. participation Methods; Independent Lab Group member and negotiations in national and international and Co-Chair of HDTV effort, Video Quality telecommunications conferences and standards Experts Group (VQEG). Rapporteur in ITU-R development organizations. WP6C for “Global video evaluation methodol- • DJ Atkinson: Chair of the Audio Perfor- ogy landscape.” Head of U.S. Delegation to mance Working Group of the Association of ITU-T Study Group 9. Public-Safety Communications Officials – In- • Patricia J. Raush: U.S. Co-chair of Working ternational and Telecommunications Industry Party 3J; Head of Delegation for WP3J; del- Association (APCO/TIA) Project 25 Interface egate to WP 3J, WP 3K, WP 3L, and WP 3M Committee (APIC) within the TIA TR-8 Mobile within ITU-R Study Group 3.

82 Technology Transfer

• Timothy J. Riley: Member of Alliance for Representative Contributions Telecommunications Industry Solutions (ATIS) ITS develops and presents user-oriented tech- committee WTSC-RAN (Wireless Technolo- nical contributions to national and international gies and Systems Committee — Radio Access standards organizations addressing require- Networks) and issue champion and editor for ments, functionality, performance, testing, qual- development of a document addressing inter- ity of service, communication network resource ference issues affecting wireless communica- management, interoperability, compliance and tion systems. Member of the U.S. delegation other topics critical to the development and to ITU-R Working Party 5D (International Mo- implementation of standardized public safety bile Telecommunications (IMT) Systems), ITU-R communications, advanced IP-based networks, Study Group 5 (Terrestrial Services). optical transport networks, next generation • Teresa Rusyn: Chair of Correspondence networks, and supporting broadband infrastructures. Many of the technical contributions Group 3K-3, Member of Working Parties 3K ITS makes to standards bodies throughout the and 3M within ITU-R Study Group 3. year contribute materially to the content of final • Frank H. Sanders: Chair of ITU-R Radar Cor- published standards. Below is a representative respondence Group (radar technical spectrum list of draft and approved technical standards issues); Delegate to ITU-R Working Party 5B and related documents that ITS staff worked on (radar spectrum allocation and sharing) and during FY 2011. Joint Rapporteurs Group 1A-1C-5B (radar • Project 25 Steering Committee P25 SoR, “APCO spectrum efficiency issues). Project 25 Statement of Requirements,” Apr. • Andrew P. Thiessen: Vice-Chair of the Tech- 2011 (R. Bloomfield) nology Committee and Chair of the Broad- • TIA TIA-102, “Project 25 System and Standards band Working Group, National Public Safety Definition,” draft in progress (R. Bloomfield) Telecommunications Council • TIA TSB-102-B, “TIA-102 Documentation Suite • Bruce R. Ward: Member, Technical Specifica- Overview,” draft in progress (R. Bloomfield) tion Group for Service and System Aspects • TIA TSB-102-BACC-B, “Inter-RF Subsystem Working Group 1 (TSG SA WG1), 3rd Genera- Interface Overview,” draft in progress (R. tion Partnership Project (3GPP) Bloomfield) • Arthur A. Webster: International Chairman • TIA TSB-102.BADA, “Telephone Interconnect Overview (Voice Service),” draft in progress (R. of ITU-T Study Group 9 (Integrated broadband Bloomfield) cable networks and television and sound • TIA TIA-102.BAEA-B, “Data Overview and transmission), and additionally SG9 contact Specification,” draft in progress (R. Bloomfield) for public relations; SG9 representative to • ATIS-P0017 “ATIS Standard on Proposed Joint ITU-T standardization committee for vocabu- ATIS/TIA Standard on Coexistence and Inter- lary (SCV), and representative to ITU-T Joint ference Issues in Land Mobile Systems” draft Coordination Activities such as those on In- in progress (T. Riley) teroperability and Conformance (JCA-CIT) and • ITU-R Recommendation SM.1541-4, “Un- Identity Management (JCA-IDM); Co-chair of wanted Emissions in the Out-of-Band Do- Video Quality Experts Group (VQEG); Co-Chair main,” Sep. 2011 (F. Sanders) of Joint Rapporteur Group on Multimedia • ITU-R Recommendation P.528, “Propagation Quality Assessment (JRG-MMQA); Member of Curves for Aeronautical Mobile and Radionavi- U.S. Delegations to ITU-T Study Group 9, Study gation Services using the VHF, UHF and SHF Group 16, Transportation Safety Advancement bands,” revision in progress (T. Rusyn) Group, ITU Council, and ITU-R WP6C. U.S. Department of Commerce voting member for ATIS Committees Network Performance, Reliability and Quality of Service Committee (PRQC) and Packet Technologies and Systems Committee (PTSC).

83 ITS Tools and Facilities

unique combination of past experience, current knowledge, specialized tools, and experi- A mental facilities enable ITS to perform research and solve complex telecommunications problems. These resources are shared through inter-agency and cooperative research and development agreements to solve telecommunications challenges for Federal and state agencies and to support technology transfer and commercialization of telecommunications products and services. Audio Visual Laboratories • Experiment design and implementation • Production of audio and video recordings that Subjective Testing Facilities match the test purpose Subjective testing is simply asking a person’s • Simulation of audio and video systems opinion. This is the most accurate way to mea- ITS has proven expertise in designing and sure the perceived quality of a phone conversa- conducting subjective experiments. Over the Audio Visual tion or video stream. past two decades, ITS has published the results Laboratory Equip- Designing a subjective test can be tricky. The from dozens of subjective experiments. ment. Above: Inside a way one asks a person’s opinion can influence One surprisingly difficult problem is audio specialized video com- the answer the person will give. Experts create and video playback. Many audio and video play- puter. This computer ITU Recommendations that list “best practices.” ers cannot guarantee that every person will see can play and record These attempt to minimize unwanted influence and hear exactly the same audio or video. ITS uncompressed HDTV on a person’s answer. When subjective tests are uses studio-quality hardware and special pur- in real time, so that the designed with care, they can be highly repeat- pose software tools to ensure reliable playback. playback system does able, that is, results are the same regardless of These playback systems often push cutting-edge not distort the video. where or when the test takes place. A controlled test environment can enhance computer hardware to its limit. Below: An assortment repeatability. A person’s attention is focused on Simulating modern audio and video distribu- of some of the mobile the task at hand since the lighting is controlled, tion is expensive because there are many meth- devices that have been there is little or no background noise, and there ods in use in the telecommunication industry. tested in the ITS Audio are no visual distractions. A controlled room The ITS audiovisual lab has a variety of hardware Video Laboratory. also frees the experimenter from considering and software tools that encode, transmit, or environmental variables when analyzing the test play audio and video, and simulate how people results. ITS has three such rooms: two are iden- use audio and video today. These tools span a tically constructed sound isolation chambers; wide range of audio and video services: one is a secluded, quiet room. • Broadcast quality audio and video The two identical rooms can be connected • Satellite TV and Cable TV to allow two persons to converse using audio, • Video on Demand video, or both. This type of testing can reveal • Streaming Internet video problems that are not apparent when people • Video teleconferencing only listen to audio recordings or view video. An • Cell phone audio and video important example is audio delay—if it is too • VoIP long, conversation becomes difficult. Audio and Video Capabilities Photos by Andrew The third subjective test room is a larger, The ITS audiovisual lab includes support for Catellier quiet room with a window. This room provides the following technologies: flexibility, but a little less control. Currently, the • Standard definition (SD) television third test room looks like a living room. This sets • High definition television (HDTV) a different context for questions about audio • Three dimensional television (3DTV) and video quality. • Monophonic, stereophonic, and 5.1-channel Unique Capabilities audio streams Because subjective testing is so time intensive • Studio quality analog and digital video record- and requires such expensive resources, only a ers with 2 to 8 audio channels few organizations in the United States perform • Digital audio recorders them. Significant expenses are: • Analog audio mixing, filtering, and equalization • Subjective test facility construction and • Studio quality video monitors, monitor loud- operation speakers, and headphones • Accurate audio and video play back • Telephone handsets

84 ITS Tools and Facilities

• Subjective test chambers compliant with ITU-T Automated Wideband Noise Rec. P.800, ITU-R Rec. BT.500, and ITU-T Rec. Measurement System P.900 To address a renewed interest in measuring, • Various hardware and software encoders and quantifying, and modeling man-made radio decoders • Internet protocol network error simulator noise, ITS developed an automated wideband compliant with ITU-T Rec. G.1050 noise measurement system. The measurement Contacts: Margaret Pinson (Video) system consists of an antenna, ITS custom-built (303) 497‑3579, [email protected]. preselector, vector signal analyzer (VSA), and gov or Steven D. Voran (audio), personal computer. The cornerstone of the (303) 497‑3839, [email protected] system is the VSA that permits wideband noise measurements in up to 36 MHz of bandwidth and the recording of digitized in-phase/quadrature (I/Q) samples of the entire noise signal. The ability of this system to record actual I and Q signal data in a wide bandwidth provides many options for processing and further use of the data. The preselector contains a fixed bandpass filter tuned to the measurement frequency, a low pass filter, and a low noise amplifier (LNA). The filters can be easily exchanged (or re- placed by a tunable bandpass filter) to conduct noise measurements at different frequencies. This configuration provides for a very sensitive measurement system with a noise figure (NF) of approximately 3 dB. The system uses a quarter- wave monopole antenna, tuned to the desired measurement frequency and mounted on a ground plane. The personal computer is used to run software developed by ITS to control the noise measurement system. This software allows the user to set the measurement frequency, bandwidth (span), number of data points, and other parameters. Once the measurement is started, the software will automatically collect data at user-defined time intervals for a user-specified duration. The software can also perform and Audio Video Laboratory facilities at ITS. Top: display results of noise diode calibrations, The video workstation includes a broadcast spectrum captures, and single, manual noise quality television, studio quality speakers, and measurement data captures. To provide a high uncompressed capture of HDTV. Acoustical degree of RF shielding between the measure- foam reduces background noise, so that subtle ment equipment and the antenna, as well as audio impairments can be heard. Center: AC power, temperature control, and shelter, the Subjective test room set up as a real world living room. Bottom: Sound isolation booth noise measurement system is currently housed set up for an audiovisual subjective test, with a in the RSMS-4G measurement vehicle. broadcast quality television and studio quality Contact: Jeffery A. Wepman, speakers. Photos by Andrew Catellier. (303) 497‑3165, [email protected]

85 Boulder Labs Frequency for MIMO studies or variable rate codes at mul- Manager tiple RF frequencies. An ITS staff person acts as the Boulder Labs The DCP receiver down-converts and digi- Frequency Manager, chairing the Boulder Labs tizes the pseudo-noise signal at an intermediate Interference Committee. This committee pro- frequency (IF) and then post-processes the data tects the Department of Commerce Boulder to calculate the channel impulse response. The Laboratories campus and the Table Mountain system can collect data on 1–8 channels every Radio Quiet Zone facilities from harmful radio 600–800 µs, allowing characterization of the frequency interference by evaluating new Doppler spectrum and time variability of the transmitters before they begin operating. mobile channel for systems up to 5.8 GHz. Propagation analyses using various propagation Historically, the DCP was employed for chan- prediction models or field measurements may nel characterization of cellular and personal be required in order to resolve potential electro- communications services. ITS has expanded the magnetic interference problems. probe to eight channels for mobile phased array The Committee has jurisdiction over all or MIMO measurements. The mobile probe’s Government and private industry users seeking measurement range has also been extended permission for frequency usage at the Table down to the UHF TV bands, where it has been Mountain Radio Quiet Zone, and over stations used for short-range mobile to mobile channel in the area that meet the following conditions characterization. In this mode of operation, a of effective radiated power (ERP) and radial variable bit rate code generator is used to al- distance: low simultaneous recordings at different band- • All stations within 2.4 km. widths and frequencies. • Stations with 50 W or more ERP within 4.8 km. Also available is a high-frequency probe, • Stations with 1 kW or more ERP within 16 km. particularly suited for high resolution require- • Stations with 25 kW or more ERP within 80 km. ments such as wireless local area network (LAN) Contact: Kristen Davis, (303) 497‑4619, applications at carrier frequencies up to 30 GHz [email protected] and bandwidths up to 500 MHz. Digital Sampling Channel Contact: Peter B. Papazian, (303) 497‑5369, Probe [email protected] The digital sampling channel probe (DCP), Frequency Allocation Forensics designed and patented by ITS, is used to characterize wideband propagation characteristics of In FY 2011, ITS completed development of the radio channel. Consisting of a transmitter, new software to measure the radio frequency receiver, and data acquisition system, the DCP is (RF) spectrum from 108 MHz to 10 GHz. The used to make impulse response measurements. Frequency Allocation Forensics prototype soft- It can be configured to transmit orthogonal ware program interactively compares actual pseudo noise codes at the same RF frequency measurements to frequency allocation records

Frequency Allocation Forensics software screen capture: Statisti- cal representations of real radio traffic in the aeronautical mobile band.

86 ITS Tools and Facilities

found in the Federal Communications Commis- evaluation of LTE (Long Term Evolution), a 4th sion (FCC) and Government Master File (GMF) generation wireless technology. databases. The site is connected to the ITS laboratories With this software, ITS measures real radio via both fiber optic and 802.11 links, and to the traffic in an area of the frequency spectrum, just Table Mountain Field Site via a microwave link. as traffic engineers might measure real vehicle The fiber optic link provides access to the ITS traffic at an intersection. Figure 1 shows a dis- local area network (LAN) while the 802.11 link play of real radio traffic measured by the Radio connects to the ITS Wireless Networks Research Spectrum Measurement Science (RSMS) system. Center. The site can provide six independent The data on the screen was post-processed to duplex fiber channels to the ITS lab. This allows provide additional statistical analysis of the raw research to be conducted over an isolated one- data. This sample screen shows data from an mile outdoor Wi-Fi link. The fiber connectivity aeronautical-mobile band from 130.5 MHz to provides a LAN connection to the outdoor wire- 135 MHz. The two graphical representations less router and the capability to operate remote show different characteristics of the measured data collection equipment. data. The top graph shows the maximum, The outdoor router, located on an 80 foot mean, and minimum signal levels of the activ- tower, provides long-range 802.11 links to ity measured in those bands over a number of other sites. These links provide 802.11b services different measurement sets. The bottom graph and are also used for network performance testing. The site’s unique location, several hundred shows the same measurements but analyzed feet above the main Department of Commerce to show the approximate amount of time that campus, allows for the provisioning of wireless a signal was present in this band. The location test links over a large portion of eastern Boulder shown on the screen is the NTIA labs in Boulder. County. Once the measured data is processed, the Contact: Christopher Behm, tool displays allocations taken from the FCC (303) 497‑3640, [email protected] and GMF databases in a separate window. In the future, the software will be used as a situational awareness tool to locate transmitters that might overload the RSMS system. The knowledge gained by using this software, both at the beginning of our measurements and after the processing steps, will ensure the value of the measurements being taken to NTIA and the community at large. Contacts: Chriss A. Hammerschmidt, (303) 497‑5958, chammerschmidt@ its.bldrdoc.gov or Geoffrey S. Sanders, (303) 497‑6736, [email protected]. Green Mountain Mesa Field Site The Green Mountain Mesa Field Site is located on the main Department of Commerce Boulder Laboratories campus. The site is used year round for outdoor wireless network research and was extensively refurbished in FY 2010. Improvements included installation of a portable building situated on a concrete pad to securely house the fiber and power distribution. Antenna towers and control center at the A new 16.8 meter (55 foot) tower was also Green Mountain Mesa Field Site. Photo by Ken constructed and raised to support research and Tilley.

87 High Performance Computing (PSAL) and Public Safety Video Laboratory (PSVL) Cluster are facilities for investigating the voice and video The HP BLADE computing cluster is an exten- quality of public safety communication systems sible platform with 32 CPU cores and 128 GB of in harsh environments. The PSAL consists of RAM. It is primarily used for running propagation digital systems for mixing, storage, and distribu- prediction models with large amounts of terrain tion of audio; sound attenuated chambers for data in parallel. The cluster allows researchers effective isolation; and International Telecom- to make significant progress towards achiev- munication Union (ITU)-compliant head and ing real-time results that are highly desirable torso simulators (HATS) for acoustic coupling to for many consumers of propagation modeling radio interfaces. The PSVL consists of cameras, data. Customized software developed at ITS al- video capture systems, video coding and decod- lows this capability to be leveraged for ITS and ing systems, network simulators, video editing joint research projects in many ways. The clus- stations, and props. ter runs both GNU/Linux and Windows Server The PSAL is built on a foundation of digital and also has the capability for virtualization of audio mixing and distribution. All audio mix- many client operating systems. The BLADE is ing, distribution, storage, and filtering are housed inside a climate-controlled server room conducted in the digital realm with 48 kHz with high available power and battery power sampled audio. This provides a high-quality, backup. There is sufficient capacity to enable distortion-free distribution system that is not rapid response to new computing challenges impacted by other equipment in the laboratory. with new hardware or techniques. All servers The digital capabilities include: digital mixing, include redundant disk arrays, and backup to a 24 track digital recording, 8 channel digital in- large disk store. The room is physically secured put and output to Windows-based computers, through an access control and security system digital audio tape (DAT), and 1/3 octave digital that logs entry by authorized personnel. filters. Usage of analog audio signals is kept to Contacts: George A. Engelbrecht, a minimum by 1) digitizing analog inputs at (303) 497‑4417, gengelbrecht@ the input and keeping them digital throughout its.bldrdoc.gov or Timothy J. Riley any processing, and 2) only performing digital- (303) 497‑5735, [email protected] to-analog conversion on signals that are to be converted to acoustic signals. Public Safety Audio and Video The more specialized equipment in the PSAL Laboratories includes the two HATS systems. The HATS sys- One of the most challenging aspects of tems are defined by the ITU in Recommendations public safety communication is the harsh noise P.58 (Head and torso simulator for telephonom- environment in which public safety practitioners etry), P.57 (Artificial ears), and P.51 (Artificial must effectively establish and conduct commu- mouth). These recommendations specify the nications. The Public Safety Audio Laboratory physical characteristics and acoustical/electrical

Public Safety Audio Laboratory audio mixing equipment and head and torso simulator (HATS). Photos by Ken Tilley.

88 ITS Tools and Facilities

interface characteristics that enable a consistent compression schemes and simulated wired and simulation of the speaking and hearing fre- wireless networks. quency responses of the “average” human. The To determine if a system is adequate for use HATS enable consistent acoustic input to com- in specified applications, first responders view munications equipment under test and provide the video and attempt to perform certain tasks a “willing subject” that will not be subject to such as identifying an object or reading a license hearing loss when exposed to harsh noise envi- plate. The results of these tests provide data for ronments for extended periods. developing recommendations. Together, the The PSAL system provides a reproducible PSAL and PSVL provide valuable insight into the acoustic path that enables emulation of the requirements for public safety audio and video harsh noise environments encountered by public communications. safety practitioners. The recorded output from Contacts: Jeff Bratcher (PSAL), (303) the system can be used in a number of ways. 497-4610, [email protected] For example, the recordings might be analyzed Joel Dumke (PSVL), (303) 497‑4418, by an objective measurement technique such [email protected] as that defined in ITU Recommendation P.862 (Perceptual evaluation of speech quality (PESQ): Public Safety RF Laboratory an objective method for end-to-end speech ITS’s Public Safety RF Laboratory (PSRF Lab) quality assessment for narrow-band telephone supports several different but related research networks and speech codecs). Alternatively, the efforts. One effort involves land mobile radio recordings might be incorporated into a subjec- (LMR) systems and components testing in active test experiment where listeners rate the cordance with the Telecommunications Industry quality of the audio. Association (TIA) Project 25 (P25) testing stan- The primary role of the PSVL is to support dards (TIA 102) for common air interface (CAI) the PSVQ project. In accomplishing this mis- performance, conformance, and interoperabil- sion, scenes that contain selected vital elements ity. ITS’s PSRF Lab contributes to those three of public safety responder uses are created and facets of the P25 CAI testing standards in order filmed on high-definition cameras. These scenes to further the goals of the Project 25 Compli- include simulations of surveillance cameras ance Assessment Program (P25 CAP). (indoor and outdoor), in-car police cameras, The PSRF Lab is also involved in the develop- and search and rescue robot cameras, among ment of interface testing regimens for the P25 others. The video is then captured and edited inter-subsystem interface (ISSI). To facilitate this on the PSVL workstations. Selected scenes are technical effort, several multi-site, multi-chan- processed through controlled versions of the nel demonstration trunking systems have been communication systems that are typical of what installed, using commercial-off-the-shelf (COTS) a jurisdiction might consider purchasing. The components from different manufacturers. communication systems processing includes The LTE Test Bed is another active effort to support the development of new public safety mobile communications technologies. The PSRF Lab hosts this test bed so that manufacturers may use it to hone public safety mobile communications products incorporating LTE, a new generation of mobile broadband access technology, before they are brought to market. While the PSRF Lab’s test and measurement capability is primarily intended to support development and maturation of public safety mobile ITS staff examine the operational configuration communications technology, the underlying characteristics of a Project 25 trunked LMR infrastructure and analysis facilities can support system in the ITS Public Safety RF lab. Photo by a much broader range of tests and radio equip- Ken Tilley. ment. This excess capability is available to other

89 Federal agencies on a first-come, first-served masts, RF transmitters, associated modulators, basis. and a precision rubidium frequency reference. Contacts: John M. Vanderau, The receiver van contains multiple antennas (303) 497‑3506, [email protected]. mounted on a large aluminum ground plane, gov or John D. Ewan, (303) 497‑3059, equipment racks, a multi-channel digitizer, [email protected]. spectrum analyzers, radio receivers, and a 5 kW on-board generator. The van has a GPS naviga- Pulsed Radar Target Generator tion system with a dead-reckoning backup. The Pulsed Radar Target Generator is an The system has two operational modes: 1) electronic tool used to produce targets on a narrowband channel probe 2) broadband chan- radar screen. The generator produces signals nel probe. In mode 1, a continuous-wave (CW) that simulate the returns that would normally signal is transmitted and received using a spec- be seen by a radar from targets in the environ- trum analyzer, vector signal analyzer, or sound ment. The signals are injected into the radar’s card/communications receiver combination. The receiver at the normal frequency of operation. received data contain path loss, a slow-fading Some radar models transmit modulated pulses. profile, and fast-fading information. The generator can produce modulated pulses The narrowband mode has high dynamic such as chirped and phase coded modulations range, sensitivity, and excellent immunity to in- (including the popular Barker code set). terference making it suitable for measurements Several parameters of the signals can be in RF-congested urban environments. The sys- adjusted over a wide range to be compatible tem can also be operated as a broadband chan- with several different radar models. For the nel probe by applying binary phase shift keying same model radar, the number of targets and (BPSK) modulation to the transmitted signal the range to the targets can be adjusted. Other using a pseudorandom number code with a adjustments include the displayed bearing of user-selectable number of bits. Post-processing the targets and whether the targets are station- yields a channel impulse response from which ary or moving along concentric circular paths. useful parameters (e.g. delay spread, basic path Compensation adjustments can be made for radars that have large tolerances in their operat- loss) can be extracted. It has the capability of ing specifications. measuring both fast- and slow-fading phenom- The targets can be set to occur at a fixed time ena as well as path loss. interval after a timing pulse (for example, at the Over the past several years, a new ultra- beginning of a scan) supplied by the radar. The wideband propagation measurement system generator can be used to verify operation or has come on line. It consists of a commercial- troubleshoot the radar under test. ITS has used off-the-shelf vector network analyzer (VNA), the generator to provide simulated desired sig- transmit and receive antennas, and an analog nals in interference studies where interference optical link. The VNA is configured to perform is injected into the radar and the effect on the 2 port S-parameter transmission measurements targets is recorded. between fixed transmit and receive antennas. Contact: Brent Bedford, (303) 497‑5288, [email protected] Radio Propagation Measurement Capabilities ITS maintains and is developing both mobile and static propagation measurement systems that address a number of wireless propagation scenarios. ITS systems cover a frequency range of 20 MHz to 30 GHz. The mobile propagation system is deployed on two vehicles: a transmitter truck and a receiver van. The transmitter truck Radio propagation measurement equipment has an on-board generator, a pair of telescoping racked in the receiver van.

90 ITS Tools and Facilities

The system covers a frequency range of 20 MHz Radio Spectrum Measurement to 18 GHz and is used to measure time- and Science (RSMS) System Tools frequency-domain propagation phenomena The Radio Spectrum Measurement Science at distances of 2–300 meters. It is configured (RSMS) measurement system is a unique, state- in a stepped-frequency mode, and S21 data of-the-art system designed for gathering infor- (amplitude and phase) are acquired and stored. mation about spectrum occupancy, equipment The resulting frequency-domain data are post- compliance, electromagnetic compatibility, and processed, inverse Fourier transformed, and interference resolution. The system provides time gated to yield propagation parameters NTIA critical measurement support for deter- such as delay spread and basic path loss. mining policies that affect Government radio This system has high accuracy and is ideal systems and spectrum utilization. for precision propagation measurements and The RSMS system is a dynamic and flexible model development/validation. The frequency- system that incorporates automated, semi- and time-domain signal processing yield high- automated, and manual techniques for the dynamic range and excellent immunity to RF measurement and analysis of radio emissions. While not defined by any single hardware con- interference. The system transmits very low figuration, the system employs state-of-the-art power levels (typically +5 dBm) and has low spectrum analyzers, digital oscilloscopes, vector interference potential to existing wireless ser- signal analyzers, and signal intercept and collec- vices. It has been used extensively for near-Earth tion systems. It is designed to be flexible enough propagation measurements at Table Mountain to accommodate implementation of mobile or with excellent path loss and channel impulse stationary measurements, in a laboratory or in response data obtained. This system also has the field. excellent range resolution capabilities that An integral part of the system is the mea- permit the isolation and evaluation of selected surement vehicle itself, now in its 4th genera- propagation events. Plans are currently being tion. The vehicle has a highly shielded enclosure made to perform indoor and building penetra- (60 dB isolation) with three full-size equipment tion measurements using this system. racks, three 10 meter telescoping masts, and a Contact: Dr. Robert Johnk, (303) 497‑3737, 20 kW diesel generator, as well as Internet con- [email protected] nections, fiber optic control lines, and a climate

The RSMS 4G truck shown during field measurements. Two of the three antenna masts have been fitted with antennas selected for the type of measurement being performed. Inside the truck, the equipment racks have been loaded with the appropriate instruments. Antennas and instruments can easily be changed to achieve the correct configuration for each measurement target.

91 control system. The control and acquisition soft- the thresholds at which various types of inter- ware is fully developed by ITS so that measure- ference from communication transmitters are ment techniques can be easily altered in new manifested as observable interference effects and innovative ways to meet immediate needs. in radar receivers. Another example would be With the completion of the 4th generation to determine the source(s) of interference from measurement software, development of the terrestrial services to space-based communica- 5th generation has begun. The objective of the tion links. 5th generation software is to provide a tool To meet these needs, ITS engineers have that can easily accommodate new equipment developed capabilities to generate interference and different hardware configurations, and signals. These signals can be coupled directly expand on existing measurement capabilities. into a system under test or they can be trans- The 5th generation of software makes use of mitted through space into a target system’s modern software tools, simplifying the design receiver to more accurately gauge its response and implementation of new measurement to a real interference situation. algorithms, as well as supporting multiple op- ITS engineers generate interference by erating systems with fewer third party software first using high-speed digitizers, called vector requirements. With less dependency on third signal analyzers (VSA), to record interference party software and compatibility with multiple waveforms in bandwidths up to 36 MHz. They operating systems, the 5th generation of soft- subsequently radiate or hardline-couple those ware has an extended application life-cycle and signals into victim receivers using vector signal reduced overall costs. generators (VSG). Alternatively, VSGs may be Contacts: John E. Carroll, (303) 497‑3367, preprogrammed with the requisite mathemati- [email protected] or Geoffrey cal information to create particular waveform A. Sanders, (303) 497‑6736, modulations, such as quadrature phase shift [email protected] keyed (QPSK) signals. The ITS interference signals can be transmit- Spectrum Compatibility Test ted with high-power amplifiers to generate and Measurement Sets high-power interference at frequencies up The introduction of new radio technologies to 26 GHz. The advantages of using VSGs to in close physical and frequency proximity to generate interference include simplicity of op- older ones can result in electromagnetic com- eration and use, plus the ability to replicate very patibility (EMC) problems. Although theoretical complex interference waveforms with complete models and simulations provide useful informa- confidence in the fidelity of the simulated signal tion in guiding design decisions, the complexity to the characteristics of the original signal from of modern systems and the existing spectral which it was derived. environment often require real-world measure- Contact: Frank H. Sanders, (303) 497‑7600, ments of a proposed system’s effects within its [email protected] operating environment to determine its impact on other spectrum users. Table Mountain Field Site and Another problem is to adequately produce Radio Quiet Zone controlled interfering signals with known char- Established in 1954, the Table Mountain Field acteristics in environments where suspected Site and Radio Quiet Zone is a unique radio interferers may be unavailable for tests and research facility. Located north of Boulder, the measurements. This includes situations such site extends about 4 kilometers (2.5 miles) north- as laboratory investigations of possible inter- south by 2.4 kilometers (1.5 miles) east-west, and ference from ship- or aircraft-mounted radars has an area of approximately 1,800 acres. The or terrestrial or space-based communications site is designated as a Radio Quiet Zone where systems. In these sorts of situations, a system the magnitude of external signals is restricted is needed that simulates the spectral emissions by State law and Federal regulation to minimize of other devices with high fidelity. An example radio-frequency interference to sensitive research of these needs is the requirement to determine projects. Facilities at the site include:

92 ITS Tools and Facilities

• Spectrum Research Laboratory—A state-of- • Two 18.3 Meter (60 Foot) Parabolic Dish An- the-art facility for research into radio spectrum tennas—These two antennas are steerable in usage and occupancy. Radio Quiet restrictions both azimuth and elevation and have been ensure that no signal incident on the mesa used at frequencies from 400 MHz to 6 GHz. overpowers any other. • Radar Test Range—A large space just south of • Open Field Radio Test Site—Table Mountain, the Spectrum Research Laboratory is available a flat-topped butte with uniform 2% slope, is for testing radar systems. uniquely suited for radio experiments. It has The Table Mountain Research program no perimeter obstructions and the ground is supports a number of research activities, e.g., relatively homogeneous. This facilitates study- studying the effects of radio propagation on ing outdoor radiation patterns from bare digital signal transmission, environmental and antennas or antennas mounted on structures. man-made noise, verification of antenna propa- • Mobile Test Vehicles—There are several mobile gation models, and the development of mea- test equipment platforms available at the site, surement methods needed to assess efficient ranging from four-wheel drive trucks to full- spectrum occupancy and usage. Partnerships featured mobile laboratories. • Large Turntable—A 10.4 meter (34 foot) and cooperative research activities with other diameter rotatable steel table mounted flush agencies are encouraged at the site. Learn more with the ground. Laboratory space underneath online at: http://www.its.bldrdoc.gov/resources/ houses test instrumentation and control equip- table_mountain. ment, and motors to rotate the turntable. The Contact: J. Wayde Allen, (303 497‑5871, facility can be operated remotely by computer. [email protected]

Table Mountain facilities. Above: rotatable steel turntable. Below: laboratory and control space under the turntable. Right: one of the two 18.3 meter (60 foot) parabolic dish antennas.

93 Telecommunications Analysis For microwave links, Fresnel zone clearance Services can be determined so that poor paths can be eliminated from a planned circuit or network. The Telecommunications Analysis (TA) Ser- • SHADOW—Plots the radio line of sight (LOS) vices program provides the latest ITS-developed regions around a specified location in the U.S. engineering models and research data to indus- using digitized topographic data. The pro- try and other Government agencies via the web. gram shows areas that are LOS to the base of User-friendly and efficient, it offers a broad the antenna, areas that are LOS to the top of range of programs that allow the user to design the antenna, and areas that are beyond LOS. or analyze the performance of telecommunica- • TERRAIN—Plots terrain elevation contours tions systems. Currently available are: online from any of the terrain databases available terrain data with 1 arc-second (30 m) resolution for CONUS and 3 arc-second (90 m) resolution (1 arc-second Spatial Data Transfer Standard for much of the world, and GLOBE (Global Land for CONUS, 3 arc-second U.S. Geological Sur- One-km Base Elevation) data for the entire vey, and GLOBE for the whole world). world; U.S. Census data for 2000, 1997 update, • COVERAGE—Calculates the received signal and 1990; FCC databases; and GIS databases levels along radials that are spaced at user- (ArcInfo). TA Services has developed models defined intervals of bearing around the trans- that predict communication system coverage mitter. The program lists the contours of signal and interference for many broadcast applica- coverage of the transmitter along each radial tions. New models in the GIS environment have and lists distances to user-specified contours been developed. Programs available through TA for each radial. Either the FCC broadcast rules Services include: or the ITS Irregular Terrain Model (ITM) can be • HAAT—Calculates Height Above Average Ter- chosen for calculations. rain for an antenna at a specified location. • CSPM—Determines the system performance • PCS/LMDS—Allows the user to create or of mobile and broadcast systems in detailed import surfaces which may include terrain, output plots of signal intensity. Plotted out- buildings, vegetation, and other obstructions puts can be faxed to the user, plotted on clear in order to perform line of sight (LOS) and dif- plastic for overlaying on geopolitical maps, or fraction studies. downloaded to the user site (in HPGL, GIF, or • FCCFIND, FMFIND, TVFIND, AMFIND, and TARGA format). This program uses the ITS ITM TOWERFIND—Allows the user to search the in a point-to-point mode, or other user-chosen FCC database for particular stations or by algorithms for path loss calculation. search radius around a point of interest. • HDTV—Allows users to analyze interference • PROFILE—Extracts path profiles according scenarios for proposed digital television (DTV) to user-specified input parameters. After the stations. The model contains current FCC and data is extracted, either the individual eleva- MSTV allotment tables and maintains the tions or an average elevation along the profile catalogs created by all program users. The can be obtained. A user can also receive plots user can create new stations by hand, or by of the profiles adjusted for various K factors. importing station information directly from

Sample outputs from TA Services programs PBS (above) and CSPM (right).

94 ITS Tools and Facilities

the FCC database. Analyses may be performed information, and RF signal quality parameters. using existing FCC database and allotment as- Another has the ability to perform provider- signments, or the user can replace a station independent PN offset scans and CDMA2000 with one created and maintained in his/her level 3 message logging. catalog. The WNRC contains an experimental IEEE • NWS—A specialized application that helps the 802.11b wireless local area network (WLAN). National Weather Service maintain its catalog ITS has conducted a series of wireless Voice of weather radio stations (currently about over IP (VoIP) tests utilizing this infrastructure. 920). The WLAN resources include IP packet log- • PBS—An analysis model similar to the HDTV ging equipment that can be used in network model, but specialized for Public Broadcasting measurements. A code domain analyzer (CDA) Services (PBS) stations. Typical outputs may measurement capability, used to collect both consist of composite plots showing Grade A short and long term Walsh channel data for any and B coverage of several stations or “overlap” target IS-95 base station, has been added to plots which show areas covered by more than the WNRC. The CDA operates in both the cel- one station. lular and PCS frequency bands and can be used • ICEPAC/VOACAP/REC533—High frequency in fixed or mobile environments. The WNRC is prediction models that can be downloaded used to conduct ITS research in the area of inter- free and executed on Windows based PCS interference, in support of the Alliance for Telecommunications Industry Solutions (ATIS) platforms. subcommittee WTSC-RAN. ITS also has the • ITM—Source code available for the ITS Irregu- capability to simulate PCS interference using a lar Terrain Model (Longley/Rice). series of ITS-implemented interference models. • IF-77—Source code available for the IF-77 Air/ Contacts: Christopher J. Behm, Ground, Air/Air, Ground/Satellite prediction (303) 497‑3640, cbehm@its. software (.1 to 20 GHz). bldrdoc.gov or Timothy J. Riley, (303) Learn more about Telecommunications 497‑5735, [email protected] Analysis Services at http://www.its.bldrdoc.gov/ resources/ta-services. Contacts: Paul M. McKenna, (303) 497‑3474, [email protected] or George Engelbrecht, (303) 497‑4417, [email protected] Wireless Networks Research Center The Wireless Networks Research Center (WNRC) provides a common laboratory area for research in wireless networks and wireless net- The ITS Wireless Networks Research Center. work access technologies. The WNRC allows ITS to consolidate efforts in several areas, such as the RF/network interface. This work uses RF link characterization correlated with low-level network management protocols to develop PCS- to-PCS interference models, wireless network propagation models, noncooperative wireless measurement, and wireless network discovery. RF/network interface measurement devices are used to make detailed measurements of PCS and cellular networks. One device uses a series of PCS/cellular phones to extract low- level protocol messages, network management

95 ITS Projects in FY 2011

NTIA Science and Engineering Project Leader: Arthur A. Webster Projects (303) 497‑3567, [email protected] Audio Quality Research Public Safety Broadband Research Develop and evaluate new techniques for en- Research, develop, and demonstrate state- coding, decoding, and analyzing speech signals. of-the-art methods and tools related to the Provide algorithms, software, and technical ex- measurement of wireless data networks, such pertise to other ITS programs. Provide technical as wireless local area networks (WLANs) and the presentations and laboratory demonstrations as use of software-defined radios (SDR) as dynami- requested. cally reconfigurable wireless network testing tools. Project Leader: Stephen D. Voran Project Leader: Dr. Robert Stafford (303) 497-3839, [email protected] (303) 497-7835, [email protected] Broadband Wireless Research Deploy state-of-the-art measurement sys- Noise and Spectrum Occupancy tems for collecting broadband radio-wave Measurement Research propagation data, to promote spectrum exten- Characterize and track over time the levels of sion, aid in the development of 3G and 4G radio channel noise in various frequency bands cellular systems, and evaluate proposed short and environments. Identify areas of greatest range unlicensed device interference. need, design and implement systems to per- Project Leader: Dr. Robert Johnk form measurements in those areas, and report on the results. Conduct spectrum usage surveys. (303) 497‑3737, [email protected] Project Leader: Jeffery A. Wepman Broadband Wireless Standards (303) 497-3165, [email protected] Provide leadership and technical support to committees (e.g., ITU-R SG 3/WP 3K, 3J, 3M, Equipment used for Noise and Spectrum Oc- and 3L, TIA TR-8) developing broadband wireless communications standards that affect Fed- cupancy Measurement Research. eral agencies’ use of the services. Building on previous ITS work, develop model comparisons for each propagation model. Project Leader: Paul M. McKenna (303) 497‑3474, [email protected] Effects of the Channel on Radio Systems Identify, model, and characterize a small number of radio systems and use these to predict the effects of the channel on others. Use the results to predict how interference introduced by new spectrum engineering methods impacts legacy systems. Project Leader: Robert J. Achatz RSMS Enhancements (303) 497‑3498, [email protected] Support RSMS operations through the Multimedia Quality Research development and maintenance of software, Develop a subjective methodology to mea- hardware, systems, and equipment. sure audiovisual quality. Create a single, cohe- Project Leader: John E. Carroll sive audiovisual model, that objectively predicts (303) 497 3367, [email protected] multimedia quality through a combination of audio quality, video quality, and audiovisual RSMS Development synchronization information. Provide new and innovative measurement Project Leader: Arthur A. Webster hardware and software tools for current and future RSMS capabilities. Project future needs (303) 497‑3567, [email protected] and develop long-term strategies for building International Standards Support the necessary tools. Provide objective, expert leadership and key Project Leader: Geoffrey A. Sanders technical contributions in ITU-T and related U.S. (303) 497‑6736, [email protected] industry committees responsible for developing broadband network performance, Quality RSMS Operations of Service (QoS), and resource management Provide NTIA with critical measurement sup- standards. port to determine radio spectrum usage across

96 ITS Projects in FY 2011

the U.S.; resolve interference problems involving Video Quality Research Government radio systems; and determine the Develop technology for assessing the per- emission characteristics of radio transmitter sys- formance of digital video transmission systems. tems that may affect Government operations. Improve measurement technology for multi- Project Leader: John E. Carroll media definition (MD) and high definition (HD) (303) 497‑3367, [email protected] video systems. Facilitate the development of international video quality measurement stan- Table Mountain Modernization dards by participating in both the Independent Maintain and upgrade the Table Mountain Lab Group (ILG) of the Video Quality Experts’ Field Site infrastructure, ensure a safe working Group (VQEG) and as a proponent for new re- environment there, and provide logistical sup- duced reference (RR) measurement technology port for research activities at the field site. for standard definition (SD) and HD TV systems. Project Leader: J. Wayde Allen Project Leader: Margaret H. Pinson (303) 497‑5871, [email protected] (303) 497‑3579, [email protected] Table Mountain Research Utilize the Table Mountain Field Site and NTIA/OSM Projects Radio Quiet Zone to support fundamental 2.7 GHz Out of Band Interference research into the nature, interaction, and evalu- Perform measurements and analysis of elec- ation of telecommunication devices, systems, tromagnetic compatibility (EMC) issues between and services in order to expand ITS’s knowledge incumbent radar systems in the 2.7–2.9 GHz base, identify emerging technologies, and de- spectrum band and other, non-radar transmit- velop new measurement methods. ter systems operating in adjacent spectrum. Project Leader: J. Wayde Allen Project Leader: Frank H. Sanders (303) 497‑5871, [email protected] (303) 497-7600, [email protected]

Research set-up at the Table Mountain Field To analyze 2.7 GHz Out of Band Interference Site and Radio Quiet Zone. to radar systems such as this air traffic control radar, engineers tested the radars with a set of known targets. Yellow circles on the inset image of a portion of the radar display show where targets are missing because they were blanked by interference. Photos by F. Sanders.

Wireless Interference Modeling and Characterization Present technical contributions on PCS interference effects to ATIS Technical Subcommittee WTSC-RAN. Contribute to related fora (e.g., Bin 1 Waveform ITU-R Working Parties 5D, 3K, and 3M) as ap- Develop new bin 1 waveforms for use by propriate. Develop a technology-independent, the FCC in conducting compliance tests on multi-channel PCS interference model for use in Unlicensed National Information Infrastructure the evaluation of CMRS and other potentially af- (U-NII) devices that use dynamic frequency se- fected (e.g., public safety) systems. lection (DFS). Project Leader: Timothy J. Riley Project Leader: Geoffrey A. Sanders (303) 497-5735, [email protected] (303) 497-6736, [email protected]

97 Integrate the Undisturbed Field Model wireless telecommunications and information Incorporate the Undisturbed Field Model technology (IT) needs. Perform technical assess- into the Short Range Mobile-to-Mobile Model ments and evaluations of existing and emerging for use by OSM in promoting efficient and ef- commercial products and services that may fective use of spectrum resources. provide interim solutions for various interoper- Project Leader: Paul M. McKenna ability scenarios. (303) 497-3474 [email protected] Project Leader: Jeff Bratcher Propagation Engineering Support (303) 497-4610 [email protected] Provide technical support to NTIA/OSM in Public Safety Communications Research (PSCR) advancing telecommunications and networking infrastructure development, improving Program Manager Dereck Orr (NIST, right) U.S. telecommunications trade opportunities, and Technical Manager Jeff Bratcher (center) advancing information technology, and pro- describing the technology being tested in this moting more efficient and effective use of the PSCR laboratory to Secretary of Commerce radio spectrum. Bryson during a recent visit. A broad range of Project Leader: Paul M. McKenna commercial communications and IT products (303) 497-3474 [email protected] are analyzed in this laboratory. Photo by Will Radar Support Tasking von Dauster. Support USWP5B, USJRG, and the U.S. Ad- ministration’s positions in ITU-R WP5B and Joint Rapporteur Group (JRG) 1A-1C-5B by providing position papers, technical reports, and atten- dance in these forums. Also support the Radar Correspondence Group (RCG) and the JRG 1A- 1C5B and RCG websites. Project Leader: Frank H. Sanders (303) 497-7600, [email protected] Spectrum Sharing Test Bed Support Evaluate equipment that uses Dynamic Spectrum Access (DSA) technology within the 410-420 MHz and 470-512 MHz bands to assess and address potential interference to incumbent spectrum users. Project Leader: Eric D. Nelson Assessment of Integration Strategies (303) 497‑7410, [email protected] Conduct engineering analyses, cost/benefit assessments, evaluations of grant proposals and Upgrade the Slope-Intercept Empirical research and development proposals, and tech- Model nical feasibility studies of emerging technologies Upgrade the current single slope Slope-Inter- to facilitate the development and/or application cept Empirical Model to a two-slope propaga- of more effective interim integration solutions tion model and provide the new models, with for public safety (that will be consistent with, supporting documentation, in a format that can or migrate logically to, the long-term standard- be used to predict radio signal attenuation. ization strategy), and to help identify ways to Project Leader: Paul M. McKenna bridge the shortcomings identified through gap (303) 497-3474 [email protected] analyses performed as part of the long-term standardization process. Other Agency Projects Project Leader: Kameron A. Behnam Department of Commerce / NIST / (303) 497-3830, [email protected] Office of Law Enforcement Standards Development of Requirements, RF Analysis, Demonstration, T&E Interoperability Standards Provide engineering support, scientific Provide applied science and engineering ex- analysis, technical liaison, and test design and pertise to OLES, and on behalf of OLES to the implementation to allow the identification, Department of Homeland Security (DHS) and development, and validation of interoperability Project SAFECOM. Solve telecommunications standards for the Justice, Public Safety, Home- interoperability and information sharing prob- land Security community, and other communi- lems among local, state, Federal, tribal, and cation system products and services supporting international Justice, Public Safety, Homeland

98 ITS Projects in FY 2011

Security agencies by addressing voice, data, image, video, and multimedia information transfers. Project Leader: Andrew P. Thiessen (303) 497-4427, [email protected] In-Building Public Safety Communications Best Practices Development Assess and report on the state of the art of in-building radio system for public safety applications. Project Leader: Frank H. Sanders (303) 497-7600, [email protected]

A diagram showing predicted coverage for an in-building radio system calculated using a site- specific radio-wave propagation model. Differ- ent colors represent different received signal power levels. Modeling in-building propagation in this manner as part of the design process is a recommended best practice.

Video sequences filmed during a simulated accident training exercise are used in Public Safety Communications Research. Top: View of the scene through a pan-tilt-zoom security camera. Remote personnel could use such a video link to monitor developing incidents. The bottom two images show the view from a P25 CAP and Public Safety Lab paramedic’s helmet camera. Middle: An arm Equipment and Support laceration is treated. The footage includes a Investigate if and how cutting edge technologies (such as 3G & 4G systems based on variety of skin tones, so that new telemedicine OFDM, CDMA, etc.) can be integrated with systems can be used to accurately diagnose existing P25 systems and/or deployed indepen- injuries on a variety of skin tones. Bottom: An dently of traditional P25 systems in order to emergency medical technician uses a wireless meet future public safety needs. Creation of a device to monitor “patient” vitals. The device 700 MHz LTE Demonstration network using the PSCR RF Lab, Green Mountain Mesa, and Table transmits video, voice, and data feeds to a re- Mountain field site. Standards development for mote hospital. Stills courtesy of www.cdvl.org. Public Safety LTE support. analyses, laboratory and field measurements, Project Leader: Jeffrey R. Bratcher and test and evaluation activities to accommo- (303) 497-4610, [email protected] date technical elements of the PSCR program Public Safety Communications and other related Federal programs supported Research and Testing by OLES. Maintain state-of-the-art laboratory Facilitate standards development efforts facilities, conduct field pilots, develop formal/in- aimed at nationwide public safety communica- formal training courses, test tools, and conduct tions interoperability and information sharing technical feasibility studies of emerging public through direct participation and technical safety interoperability technologies. contribution to the appropriate Standards Project Leader: Jeffrey R. Bratcher Development Organizations. Conduct scientific (303) 497-4610, [email protected]

99 Public Safety Telecommunications Project Leader: Julie Kub Interoperability (303) 497-4607, [email protected] Provide engineering support, scientific DOD / U.S. Air Force analysis, technical liaison, and test design and implementation to allow the identification, FPS-124 and RNSS EMC/Spectrum development, and validation of interoperability Study standards for the justice/public safety/homeland Assist the Air Force to examine mitigation security community. Support the joint NTIA/ITS techniques between RNSS signals and radar sys- and NIST/OLES Public Safety Communications tems operating in the 1215–1390 MHz frequency Research (PSCR) program. Provide technical band. Perform radar emission measurements on assessments and evaluations of commercial the AN/FPS-124. Spectral emission data will be products and services that may provide interim used to quantify the amount of energy, if any, solutions for various interoperability scenarios. that is radiated in the EESS and WMTS bands, Project Leader: Jeffrey R. Bratcher from 1390–1400 MHz and to provide a complete FPS-124 emission spectrum, a determination of (303) 497-4610, [email protected] transmitter bandwidths, calculated spurious and Public Safety Video Quality Assessment harmonic emission levels, and, if possible, a plot Determine one-way transmission minimum of the azimuthal antenna pattern. performance specifications for a wide range of Project Leader: John E. Carroll task-based public safety video application areas (303) 497-3367 [email protected] that involve the ability to recognize the target of interest for a particular scenario (visual intel- Department of Homeland Security ligibility or visual acuity). (DHS) / Office of Emergency Communications Project Leader: Dr. Joel Dumke (303) 497-4418, [email protected] Investigative Device Measurement Methods Video Clip Preparation Develop standardized measurement methods Film, edit, organize, and document high for body wire systems and other investigative de- quality video sequences suitable for objective vices. Support the Federal Partnership for Interop- and subjective analysis of the suitability of video erable Communications standards committee. equipment for public safety purposes, with Support public safety practitioner involvement appropriate usage permissions and content. in the PSCR Broadband Demonstration Network Design and film new video sequences, edit new Project Leader: Jeffrey R. Bratcher and existing footage, organize footage into sce- (303) 497-4610, [email protected] NOAA Weather Radio nario groups, document the video sequences, (NWR) broadcasts and convert footage into multiple formats. DHS / Office of the CIO warning and post- Project Leader: Margaret H. Pinson Investigative Device Testing event information for (303) 497-3579, [email protected] Provide engineering and technical support to DHS Office of the CIO for development of stan- all types of natural and Department of Commerce / NOAA / dardized measurement methods of investigative man-made hazards 24 NOAA Weather Radio Program Office devices. Conduct measurements on new and/or hours a day on one of NOAA Weather Radio Receiver Tests proposed investigative devices defined by DHS. seven VHF frequencies Test the responses of selected commercial Project Leader: Jeff Bratcher from 162.400 MHz NOAA Weather Radio (NWR) receivers to vari- (303) 497-4610 [email protected] to 162.550 MHz ous simulated NWR transmissions using a series and cannot be heard of repeatable measurement methods. Compile DHS / U.S. Coast Guard on a simple AM/FM and report on the characteristics and responses Radar EMC Study of the tested receivers As applicable, determine radio receiver. ITS Develop computer models of typical solid whether the receivers comply with the stan- state and magnetron-based S-Band Marine assists in developing dards set down in CEA 2009. Radar receivers and perform EMI analyses and performance standards Project Leader: Raian F. Kaiser parametric studies of potential interference from that weather radios (303) 497‑5491, [email protected] Broadband Wireless devices operating within must meet and tests the band, and from devices and radars operat- Department of Defense (DOD) for reception they must ing in adjacent bands. Where necessary, supple- pass before manufac- Propagation Modeling Web site (PMW) ment these computer models by measurements Develop and enhance a web-based multipur- performed on selected radar receivers. Develop turers are permitted pose GIS propagation modeling tool to predict recommended Marine Radar receiver selectivity to display the NWR All coverage, interference and overlap coverage of standards to minimize interference from and Hazards logo pictured outdoor broadcast systems for frequencies up define reasonable adjacent band/out-of-band above on their radios. to 20 GHz. emissions (OOBE) limits for broadband wireless

100 ITS Projects in FY 2011

devices. Monitor related Broadband Wireless 200 localities where some automotive control spectrum reallocation efforts and FCC regula- systems may have experienced compromising tory actions and rulemaking efforts. failures. Project Leader: Frank H. Sanders Project Leader: Dr. Robert Johnk (303) 497-7600, [email protected] (303) 497‑3737, [email protected] Department of Interior / National Park L-Band Interference Thresholds Service Obtain, for the receivers of FAA long-range Acadia National Park Communications radars ARSR-3, ARSR-4, and CARSR, the inter- Alternatives Study ference duty cycle threshold below which emis- Provide coverage plots of the present com- sions from the planned NASA JPL Soil Moisture munications capabilities at Acadia National Active/Passive (SMAP) orbital radar will not Park. Perform single, double, and triple alterna- cause loss of desired targets by terrestrial radars. tive base station location evaluations. Provide Project Leader: Frank H. Sanders analysis tools to assess the viability of each (303) 497-7600, [email protected] alternative. Project Leader: Christopher Behm A rendering of SMAP in orbit with a visualiza- (303) 497-3640, [email protected] tion of the swath of data streaming to Earth on L-band transmissions. Image courtesy of NASA/ SERC Communications Specification Conduct propagation prediction studies of JPL-Caltech. the Schoodic Education and Research Center (SERC) facility to establish optimum locations for transmitters to augment current cellular coverage within SERC. Determine the technical operating parameters (such as bandwidth, throughput, and capacity) required to supply researchers and students visiting the SERC with maximum service possible. Develop a technical plan that details hardware requirements to implement cellular coverage within the SERC. Project Leader: Christopher Behm (303) 497-3640, [email protected] Department of Transportation / Federal Railroad Administration National Archives and Records Railroad Telecommunications Study Administration Provide engineering services and products to the Federal Railroad Administration Office of Re- NARA e-Government Study search and Development, including testing VNB Provide the technical backbone for the pro- digital radios’ audio quality in a railroad environ- posed electronic Federal Record Center (eFRC). ment, evaluating the efficacy of the VHF channel Working closely with NARA archivists, design plan, evaluating propagation models as applied and implement a potentially large scale records to railroad environments, and verifying RF perfor- management infrastructure to administer, store, mance metrics of very narrowband digital radios. and manage temporary e-records in compliance Prepare technical contribution pertaining to rail- with well-established NARA RM requirements, road telecommunications for the Association of including support for automation of NARA busi- American Railroads’ (AAR) Wireless Communica- ness processes through electronic workflow. tions Committee (WCC). Project Leader: Michael G. Cotton Project Leader: John M. Vanderau (303) 497‑7346, [email protected] (303) 497-3506, [email protected] Various Federal & Non-Federal Agencies National Aeronautics and Space Telecommunications Analysis Services Administration Develop and maintain TA Services analysis Intentional Emitter Study tools (propagation models) and their cor- Perform a review of the current versions of responding interfaces to users and databases, the FCC licensing database and the Government including maintenance and development of Master File (GMF) to identify, charatecterize GUIs and various databases. and catalog licensed or assigned radio trans- Project Leader: Julie Kub mitters within approximately 8 km of about (303) 497‑4607, [email protected]

101 Abbreviations/Acronyms

3DTV three-dimensional television DNSSEC Domain Name System Security 3G third generation cellular wireless Extensions 3GPP 3rd Generation Partnership Project DOC Department of Commerce 4G fourth generation cellular wireless DOD Department of Defense AAR Association of American Railroads DOE Department of Energy AC alternating current DOJ Department of Justice ADC analog to digital converter DSA dynamic spectrum access ANSI American National Standards DSR Document & Standards Reference Institute DTV digital television APCO Association of Public-Safety eFRC electronic Federal Record Center Communications Officials EMC electromagnetic compatibility – International EMS emergency medical services APIC APCO Project 25 Interface ERB Editorial Review Board Committee ERIC Emergency Response APD amplitude probability distribution Interoperability Center APWG Audio Performance Working Group ERP effective radiated power ARNS aeronautical radionavigation ESRI Environmental Systems Research system Institute ARSR Air Route Surveillance Radar FAA Federal Aviation Administration ATIS Alliance for Telecommunications FCC Federal Communications Industry Solutions Commission AUGNet Ad Hoc UAV Ground Network FEMA Federal Emergency Management BPL broadband over power line Agency BPSK binary phase shift keying FLC Federal Laboratory Consortium BRS broadband radio service FM frequency modulation BVQM Batch VQM FMCW frequency-modulated CAI Common Air Interface continuous-wave CAP Compliance Assessment Program FR full reference CDA Code Domain Analyzer FSSI Fixed Station Subsystem Interface CDMA Code Division Multiple Acces FTTA Federal Technology Transfer Act CDVL Consumer Digital Video Library FY fiscal year CEA Consumer Electronics Association GAST gradient ascent subjective testing CIF common intermediate format GHz gigahertz CMRS Commercial Mobile Radio Services GIF graphical interchange format CONUS continental United States GIS geographic information system COPS Community Oriented Policing GLOBE Global Land One-km Base Services Elevation COTS commercial-off-the-shelf GMF Government Master File CRADA cooperative research and GPS Global Positioning System development agreement GUC generalized use class CARSR Common Air Route Surveillance HATS head and torso simulator Radar HD high definition CSPT Communication System Planning HDTV high definition television Tool HF high frequency CSSI Console Subsystem Interface HPGL Hewlett-Packard Graphics CW continuous wave Language DAT digital audio tape HRTe high-resolution terrain elevation dB decibel IBOC in-band on-channel DCP digital sampling channel probe IBRES in-building radio enhancement DFS dynamic frequency selection system DHS Department of Homeland Security IEC International Electrotechnical DNS domain name system Commission

102 Abbreviations/Acronyms

IEEE Institute of Electrical and LTE long term evolution Electronics Engineers MD multimedia definition IF intermediate frequency MHz megahertz IF-77 ITS-FAA 1977 propagation model MIMO multiple input multiple output IFSAR interferometric synthetic aperture MMES multimedia emergency services radar MOS Mean Opinion Score ILG Independent Lab Group MSS mobile satellite services IMSI International Mobile Subscriber MSTV Association for Maximum Service Identity Television IMT International Mobile NARA National Archives and Records Telecommunications Administration INR interference to noise ratio NASA National Aeronautics and Space IOC IMSI Oversight Council Administration IP Internet protocol NAVFAC Navy Facilities Engineering IPC interference protection criteria Command I/Q in-phase/quadrature NF noise figure IRAC Interdepartment Radio Advisory NIST National Institute of Standards and Committee Technology ISART International Symposium on NOAA National Oceanic and Atmospheric Advanced Radio Technologies Administration ISSI Inter-RF Subsystem Interface NPR National Public Radio IT Information Technology NPSTC National Public Safety Telecommunications Council ITM Irregular Terrain Model NS/EP national security/emergency ITS Institute for Telecommunication preparedness Sciences NSWC Naval Surface Warfare Center ITS_UFED ITS Undisturbed-Field and NTIA National Telecommunications and Empirically Derived Information Administration ITU International Telecommunication NWR NOAA Weather Radio Union NWS National Weather Service ITU-R ITU Radiocommunication Sector OFDM orthogonal frequency-division ITU-T ITU Telecommunication multiplexing Standardization Sector OIC Office of Interoperability and IWCE International Workshop on Compatibility Computational Electronics OLES Office of Law Enforcement JCA-CIT Joint Coordination Activity on Standards Interoperability and Conformance OOB out-of-band JCA-IDM Joint Coordination Activity on Identity Management OOBE out-of-band emission OSM Office of Spectrum Management JRG Joint Rapporteur Group P25 Project 25 JRG-MMQA Joint Rapporteur Group on Multimedia Quality Assessment PASS personal alert safety system kHz kilohertz PBS Public Broadcasting Service km kilometer PCAP P25 Compliance Assessment Program kW kilowatt PCS Personal Communications Service LADAR laser detection and ranging PESQ perceptual evaluation of speech LAN local area network quality LFMF low frequency/medium frequency PLMN ID Public Land Mobile Network LIDAR Light Detection and Ranging Identifier LMCO Lockheed Martin Company PMW Propagation Modeling Website LMDS local multipoint distribution system PN pseudorandom number LMR land mobile radio PRQC Network Performance, Reliability LNA low noise amplifier and Quality of Service Committee LOS line of sight PSAL Public Safety Audio Laboratory

103 PSCR Public Safety Communications TIREM Terrain Integrated Rough Earth Research Model PSNR peak signal-to-noise ratio TR technical report PSRF Public Safety RF Laboratory TSB Telecommunications Systems PSVL Public Safety Video Laboratory Bulletin PSVQ Public Safety Video Quality TSC Technical Subcommittee PTSC Packet Technologies and Systems TSG Technical Specification Group Committee TV television QCIF Quarter Common Intermediate U.S. United States Format UA unmanned aircraft QoE quality of experience UAS unmanned aircraft system QoMEX International Workshop on Quality UAV unmanned aerial vehicle of Multimedia Experience UHF ultra high frequency QoS quality of service ULA United Launch Alliance R&D research and development U-NII Unlicensed National Information RECUV Research and Education Center for Infrastructure Unmanned Vehicles UNS User Needs Subcommittee RF radio frequency URSI International Union of Radio RFSS Radio Frequency Sub-System Science ROTHR Relocatable Over the Horizon USNC United States National Committee Radar USRP universal software radio peripheral RR reduced reference UT universal time RSEC Radar Spectrum Engineering UWB ultrawideband Criteria VFD variable frame delay RSMS Radio Spectrum Measurement VHF very high frequency Science VNA vector network analyzer SCEP Student Career Experience Program VoIP voice over Internet protocol SCTE Society of Cable VQEG Video Quality Experts Group Telecommunications Engineers VQiPS Video Quality in Public Safety SD standard definition VQM Video Quality Model SDR software-defined radio VQM_VFD Video Quality Model with Variable SERC Schoodic Education and Research Frame Delay Center VSA vector signal analyzer SG Study Group VSG vector signal generator SHF super high frequency W watt SLiMS Shore Line Intrusion Monitoring WCC Wireless Communications System Committee SMAP Soil Moisture Active/Passive orbital W-CDMA wideband CDMA radar WG Working Group SNR signal-to-noise ratio Wi3 Wireless Innovation and SoR Statement of Requirements Infrastructure Initiative SPIE Society of Photo-Optical WLAN wireless local area network Instrumentation Engineers WNRC Wireless Networks Research Center SRS satellite remote sensing WP Working Party ST spatialtemporal WRC World Radiocommunication STEP Student Temporary Employment Conference Program WTSC-RAN Wireless Technologies and Systems TA Telecommunications Analysis Committee – Radio Access Networks TARGA Truevision Advanced Raster Graphics Adapter TDWR Terminal Doppler Weather Radar TIA Telecommunications Industry Association

104 DOC/NTIA Organization Chart

U.S. Department of Commerce

National National International Bureau of Economics U. S. Patent Oceanic and Institute of Trade Industry and and Statistics and Trademark Atmospheric Standards and Administration Security Administration Office Administration Technology

National Minority Economic Telecommunications Business Development and Information Development Administration Administration Agency

Office of Office of Policy Office of Spectrum Office of Telecommunications Analysis and Management International Affairs and Information Development Applications

Office of Policy Office of Office of Public Office of the Coordination and Congressional Affairs Chief Counsel Management Affairs

Institute for Telecommunication Sciences