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H0 STET LER LQPCKET File Copy ORIGINAL
BAKER & H 0 S T E T LER LQPCKET FilE copy ORIGINAL COUNSELLORS AT LAW WASHINGTON SQUARE, SUITE 1100 • 1050 CONNECTICUT AVENUE, N.W. • WASHINGTON, D.C. 20036-5304 • (202) 861-1500 FAX (202) 861-1783 WRITER'S DIRECT DIAL NUMBER (202) 861-1624 December 17, 1997 VIA HAND DELIVERY Ms. Magalie Roman Salas Secretary Federal Communications Commission 1919 M Street, N.W. Room 222 Washington, D.C. 20554 Re: Advanced Television Systems and Their Impact upon the Existing Television Broadcast Service MM Docket No. 87-268 Comments Dear Ms .. Salas: We are transmitting herewith the original and five copies of the comments of Scripps Howard Broadcasting Company in the above captioned proceeding. The comments are filed pursuant to the Commission's Public Notice of December 2, 1997. Please contact the undersigned if you have any questions. Donald Enclosures (JJ-~ No. of Copies rec'd_. _ List ABCDE ORLANDO, FLORIDA CLEVELAND. OHIO COLUMBUS, OHIO DENVER. COLORADO HOUSTON. TEXAS LONG BEACH, CALIFORNIA Los ANGELES. CALIFORNIA (216) 621-0200 (614) 228-1541 (303) 861-0600 (713) 751-1600 (562) 432-2827 (213) 624-2400 (407) 649-4000 Before the DOCKET ALE CQPY ORlGlNAL FEDERAL COMMUNICATIONS COMMISSION Washington, D.C. 20554 In the matter of ) ) FCC SEEKS COMMENTS ON FILINGS ) ADDRESSING DIGITAL ) TV ALLOTMENTS, PUBLIC NOTICE ) dated December 2, 1997 ) TO: The Commission COMMENTS SUBMITTED BY SCRIPPS HOWARD BROADCASTING COMPANY These comments by Scripps Howard Broadcasting Company (SHBC) are in response to the PUBLIC NOTICE from the Federal Communications Commission (FCC) dated December 2, 1997 and signed by Richard M. Smith, Chief, Office ofEngineering and Technology. -
Numerical Modelling of VLF Radio Wave Propagation Through Earth-Ionosphere Waveguide and Its Application to Sudden Ionospheric Disturbances
Numerical Modelling of VLF Radio Wave Propagation through Earth-Ionosphere Waveguide and its application to Sudden Ionospheric istur!ances Thesis submitted for the degree of octor of Philosoph# (Science% in Ph#sics (Theoretical) of the &niversity of 'alcutta Su(a# Pal Ma#8, )*+, CERTIFICATE FROM THE SUPERVISOR This is to certify that the thesis entitled "Numerical Modelling of VLF Radio Wave Propagation through Earth-Ionosphere waveguide and its application to !udden Ionospheric Distur#ances", submitted by Mr. Sujay Pal who got his name registered on $%&$'&%$(( for the award of Ph.D. )!cience* degree of the Universit, of Calcutta. absolutely based upon his own work under the supervision of Professor !andip K. Cha0ra#arti and that neither this thesis nor any part of it has been submitted for any degree/diploma or any other academic award anywhere before. Prof. !andip K. -ha0ra#arti Senior Professor & Head Department of #strophysics & Cosmology S. N. Bose National Centre for Basic Sciences JD Block, Sector())), Salt *ake, +olkata 7---./, India TO My PARENTS i ABSTRACT Very Low Frequency (VLF) radio waves with frequency in the range 3 30 kHz ∼ propagate within the Earth-ionosphere waveguide (EIWG) for#ed $y the Earth as the %ower $oundary and the %ower ionosphere (50 100 k#) as the upper $oundary ∼ of the waveguide. These waves are generated from #an-#ade transmitters as wel% as fro# lightnings or other natura% sources( *tudy of these waves is very i#portant since they are the only tool to diagnose the %ower ionosphere( Lower part of the Earth+s ionosphere ranging &0 90 km is known as the -- ∼ region of the ionosphere( *olar Lyman-α radiation at '.'./ n# and EUV radiation in 80 '''.& n# are #ain%y responsib%e for for#ing the --region through the ∼ ionization of 123N 23O 2 during day time( The VLF propagation takes p%ace $etween the Earth+s surface and the --region at the day time. -
Experimental Results of Network-Assisted Interference Suppression Scheme Using Adaptive Beam-Tilt Switching
Hindawi International Journal of Antennas and Propagation Volume 2017, Article ID 2164038, 10 pages https://doi.org/10.1155/2017/2164038 Research Article Experimental Results of Network-Assisted Interference Suppression Scheme Using Adaptive Beam-Tilt Switching Tomoki Murakami,1 Riichi Kudo,1 Koichi Ishihara,1 Masato Mizoguchi,1 and Naoki Honma2 1 NTT Access Network Service Systems Laboratories, Nippon Telegraph and Telephone Corporation, Yokosuka, Japan 2Faculty of Engineering, Iwate University, Morioka, Japan Correspondence should be addressed to Tomoki Murakami; [email protected] Received 4 October 2016; Accepted 18 April 2017; Published 14 May 2017 Academic Editor: Ahmed Toaha Mobashsher Copyright © 2017 Tomoki Murakami et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. This paper introduces a network-assisted interference suppression scheme using beam-tilt switching per frame for wireless local area network systems and its effectiveness in an actual indoor environment. In the proposed scheme, two access points simultaneously transmit to their own desired station by adjusting angle of beam-tilt including transmit power assisted from network server for the improvement of system throughput. In the conventional researches, it is widely known that beam-tilt is effective for ICI suppression in the outdoor scenario. However, the indoor effectiveness of beam-tilt for ICI suppression has not yet been indicated from the experimental evaluation. Thus, this paper indicates the effectiveness of the proposed scheme by analyzing multiple-input multiple- output channel matrices from experimental measurements in an office environment. -
Uhf Slot Antenna
UHF SLOT ANTENNA PROSTAR SERIES Proven performance, quality and reliability Rugged construction Directional patterns standard & custom High power rating to achieve 5 megawatts Custom electrical & mechanical beam tilt Horizontal, circular & elliptical polarization ELECTRICAL SPECIFICATIONS Polarization Horizontal, Elliptical, Circular Power Rating 1 kW to 90 kW Beam Tilt As specified by customer Null Fill As specified by customer Input Impedance 50 or 75 ohm VSWR 1.1:1 or better across band 6340 Sky Creek Dr, Sacramento, CA 95828 | T: 916.383.1177 | F: 916.383.1182 JAMPRO.com UHF SLOT ANTENNA SELECTING YOUR SLOT ANTENNA Compatible with DTV, NTSC and PAL Broadcasts JA-LS: 1 kW JAMPRO’s LOW POWER slot antenna is designed with the needs of low power UHF broadcasters in mind. Aluminum construction ensures excellent weather resistance while residing windload and weight on the tower. The unique design of the low power UHF slot antenna can be configured to provide varying levels of vertically polarized signal. The versatility of the slots allows them to be top, leg or face mounted. JA-MS: 1 to 30 kW JAMPRO’s JA/MS is the harsh environment version of the JA/LS antenna. The JA/MS is also enclosed by white UV resistant radomes for added protection from the environment. The JA/MS is an excellent choice for low power UHF broadcasters located in areas with heavy air pollution or high salt content in the air. JSL-SERIES: 5 to 40 kW JAMPRO’s Premium LOW POWER slot antenna, using marine brass, copper and virgin Teflon in construc- tion, is the finest antenna of its type. -
Propagation Analysis of a 900 Mhz Spread Spectrum Centralized Traffic Signal Control System
PROPAGATION ANALYSIS OF A 900 MH Z SPREAD SPECTRUM CENTRALIZED TRAFFIC SIGNAL CONTROL SYSTEM Brian L. Urban, AS, BS, EIT Thesis Prepared for the Degree of MASTER OF SCIENCE UNIVERSITY OF NORTH TEXAS May 2006 APPROVED: Perry McNeill, Major Professor Michael Kozak, Committee Member Shuping Wang, Committee Member Bernard Vokoun, Committee Member Vijay Vaidyanathan, Departmental Program Coordinator Albert B. Grubbs, Chair of the Department of Engineering Technology Oscar Garcia, Dean of the College of Engineering Sandra L. Terrell, Dean of the Robert B. Toulouse School of Graduate Studies Urban, Brian L., Propagation analysis of a 900 MHz spread spectrum centralized traffic signal control system. Master of Science (Engineering Technology), May 2006, 88 pp., 20 tables, 27 illustrations, references, 25 titles. The objective of this research is to investigate different propagation models to determine if specified models accurately predict received signal levels for short path 900 MHz spread spectrum radio systems. The City of Denton, Texas provided data and physical facilities used in the course of this study. The literature review indicates that propagation models have not been studied specifically for short path spread spectrum radio systems. This work should provide guidelines and be a useful example for planning and implementing such radio systems. The propagation model involves the following considerations: analysis of intervening terrain, path length, and fixed system gains and losses. Copyright 2006 by Brian L. Urban ii ACKNOWLEDGEMENTS I acknowledge the following people for their efforts and contributions to my thesis. It would not have been completed without them. Special thanks to the author’s thesis advisor, Dr. -
R&D Report 1965-08
-- --------~ ---~------------'"-~~~~-----~ -----..:.-....-~---------"'--'---~--:~~---~-- RESEARCH DEPARTMENT SPECIFICATION OF THE IMPEDANCE OF TRANSMITTING AERIALS FOR MONOCHROME AND COLOUR TELEVISION SIGNALS Technological Report No. E-ll5 (1965/8) D.J. Why the , B.Sc.(Eng.), A.M.LE.E. for Head of Research Department --~-~ ------~:..~-~-~- ---- --------------- -- --------~-------- This Report Is the property ot the British Broadcasting Corporation and may not be reproduced in any form .ithout the written permission o~ the Corporation. - --". - - ~ ---------~------------- ~---~--.----------~~ -.:-'-. Technological Report No. E-115 SPECIFICATION OF mE IMPEDANCE OF TRANSMITTING AERIALS FOR MONOCHROME AND COLOUR TELEVISION SIGNALS Section Title Page SUMMARY ... 1 1. INTRODUCTION 1 2. 405-LINE MONOaIROME SYSTEM 2 2.1. Short-delay Reflexions. 2 2.2. Long-delay Reflexions . 2 3. 625-LINE MONOaIROME SYSTEM 3 3.1. Application of 405-line Results 3 3.2. Short-delay Reflexions 3 3.3. Long-delay Reflexions 4 4. 625-LINE COLOUR SYSTEM 4 4.1. General . 4 4.2. Short-delay Reflexions 5 4.3. Long-delay Reflexions 5 4.3.1. General 5 4.3.2. Subj ecti ve Tests 5 4.3.3. Results of Subjective Tests. 8 4.3.4. Resulting Specification 10 5. REFLEXIONS DUE TO FEEDER IRREGULARITIES 11 6. APPLICATION TO PRACTICAL INSTALLATIONS 12 6.1. The Aerial Impedance Specification . 12 6.1.1. The Effect of Loss in the Feeder and Combining Filters. 12 6.1.2. The Effect of Loss in Re-reflexion at the Transmitter. 12 C~~~~_~~_~ ________: ______ ~ ________ ~~~ ___ ~~ _______ ~ __ ~~ _______ ~ __ ~ _______ ~~ __ _ Section Title Page 6.2. Specification of Reflexions due to Feeder Irregulari ties,. 14 6.2.1. -
VLF Radio Observations and Modeling
INDIAN CENTRE FOR SPACE PHYSICS ANNUAL REPORT (2013-2014) TABLE OF CONTENTS Report of the Governing Body 3 Governing Body of the Centre 4 Members of the Research Advisory Council 4 Academic Council Members 4 In-Charge, Academic Affairs 4 Dean (Academic) and Finance Officer 4 Administrative Officer 4 Public Information Officer 5 In Charge of the Departments 5 Faculty Members 5 Honorary Faculty Members 5 Project Scientists 5 Post-Doctoral Fellows 5 Senior Research Fellows 5 Junior Research Fellows 6 ICTP Senior Research Fellow 6 Visiting Research Scholars 6 Engineers / Laboratory Staff 6 Office Staff 6 Security Staff 6 Research Facilities at the Head Quarter 7 Facilities at other branches of the Centre 7 Brief Profiles of the Scientists of the Centre 7 Research Work Published or Accepted for Publication 10 Books and In Books 14 Members of Scientific Societies/Committees 15 Ph.D. degree Received 15 Ph.D. Thesis Submitted 15 Course of lectures offered by ICSP members 15 Participation in National/International Conferences & Symposia 16 Workshops / Seminars / Conferences etc. organized 17 Visits abroad from the Centre 17 Major Visitors to the Centre 17 Collaborative Research and Project Work 17 M.Sc. projects guided by ICSP members 18 Summary of the Research Activities of the Scientists at the Centre 19 The ionospheric and earthquake research centre (IERC) 38 Activities of the Indian Centre for Space Physics, Malda Branch 40 Auditors Report to the Members 42 Published by: Indian Centre for Space Physics, Chalantika 43, Garia Station Road, Garia, Kolkata 700084 EPABX +91-33-2436-6003 and +91-33-2462-2153 Extension Numbers: Department of Ionospheric Science: 21 Department of Astrochemistry/Astrobiology: 22 Accounts: 23 Seminar Room: 24 Computer room: 25 Department of High Energy Radiation: 26 X-ray Laboratory: 27 Fax: +91-33-2462-2153 E-mail: [email protected] Website: http://csp.res.in Front Cover: Superposed photos of the earth taken from a camera on board a balloon borne mission and the sky at Ionospheric and Earthquake Research Center of ICSP taken by Mr. -
HF Radio Propagation
Introduction to HF Radio Propagation 1. The Ionosphere 1.1 The Regions of the Ionosphere In a region extending from a height of about 50 km to over 500 km, most of the molecules of the atmosphere are ionised by radiation from the Sun. This region is called the ionosphere (see Figure 1.1). Ionisation is the process in which electrons, which are negatively charged, are removed from neutral atoms or molecules to leave positively charged ions and free electrons. It is the ions that give their name to the ionosphere, but it is the much lighter and more freely moving electrons which are important in terms of HF (high frequency) radio propagation. The free electrons in the ionosphere cause HF radio waves to be refracted (bent) and eventually reflected back to earth. The greater the density of electrons, the higher the frequencies that can be reflected. During the day there may be four regions present called the D, E, F1 and F2 regions. Their approximate height ranges are: • D region 50 to 90 km; • E region 90 to 140 km; • F1 region 140 to 210 km; • F2 region over 210 km. At certain times during the solar cycle the F1 region may not be distinct from the F2 region with the two merging to form an F region. At night the D, E and F1 regions become very much depleted of free electrons, leaving only the F2 region available for communications. Only the E, F1 and F2 regions refract HF waves. The D region is very important though, because while it does not refract HF radio waves, it does absorb or attenuate them (see Section 1.5). -
Time and Frequency Users' Manual
,>'.)*• r>rJfl HKra mitt* >\ « i If I * I IT I . Ip I * .aference nbs Publi- cations / % ^m \ NBS TECHNICAL NOTE 695 U.S. DEPARTMENT OF COMMERCE/National Bureau of Standards Time and Frequency Users' Manual 100 .U5753 No. 695 1977 NATIONAL BUREAU OF STANDARDS 1 The National Bureau of Standards was established by an act of Congress March 3, 1901. The Bureau's overall goal is to strengthen and advance the Nation's science and technology and facilitate their effective application for public benefit To this end, the Bureau conducts research and provides: (1) a basis for the Nation's physical measurement system, (2) scientific and technological services for industry and government, a technical (3) basis for equity in trade, and (4) technical services to pro- mote public safety. The Bureau consists of the Institute for Basic Standards, the Institute for Materials Research the Institute for Applied Technology, the Institute for Computer Sciences and Technology, the Office for Information Programs, and the Office of Experimental Technology Incentives Program. THE INSTITUTE FOR BASIC STANDARDS provides the central basis within the United States of a complete and consist- ent system of physical measurement; coordinates that system with measurement systems of other nations; and furnishes essen- tial services leading to accurate and uniform physical measurements throughout the Nation's scientific community, industry, and commerce. The Institute consists of the Office of Measurement Services, and the following center and divisions: Applied Mathematics -
IJEST Template
Research & Reviews: Journal of Space Science & Technology ISSN: 2321-2837 (Online), ISSN: 2321-6506 V(Print) Volume 6, Issue 2 www.stmjournals.com Diurnal Variation of VLF Radio Wave Signal Strength at 19.8 and 24 kHz Received at Khatav India (16o46ʹN, 75o53ʹE) A.K. Sharma1, C.T. More2,* 1Department of Physics, Shivaji University, Kolhapur, Maharashtra, India 2Department of Physics, Miraj Mahavidyalaya, Miraj, Maharashtra, India Abstract The period from August 2009 to July 2010 was considered as a solar minimum period. In this period, solar activity like solar X-ray flares, solar wind, coronal mass ejections were at minimum level. In this research, it is focused on detailed study of diurnal behavior of VLF field strength of the waves transmitted by VLF station NWC Australia (19.8 kHz) and VLF station NAA, America (24 kHz). This research was carried out by using VLF Field strength Monitoring System located at Khatav India (16o46ʹN, 75o53ʹE) during the period August 2009 to July 2010. This study explores how the ionosphere and VLF radio waves react to the solar radiation. In case of NWC (19.8 kHz), the signal strength recording shows diurnal variation which depends on illumination of the propagation path by the sunlight. This also shows that the signal strength varies according to the solar zenith angle during daytime. In case of VLF signal transmitted by NAA at 24 kHz, the number of sunrises and sunsets are observed in VLF signal strength due to the variations of illumination of the D-region during daytime. In both the cases, the signal strength is more stable during daytime and fluctuating during nighttime due to the presence and absence of D-region during daytime and nighttime respectively. -
Antenna Design for Future Broadcast Technology
BROADCAST ANTENNA DESIGN TO SUPPORT FUTURE TRANSMISSION TECHNOLOGIES John L. Schadler Director of Antenna Development Dielectric L.L.C. Raymond, ME. Summary done by increasing the beam tilt at one site in order to reduce the amount of coverage area and thus the amount It doesn’t matter what future television transmission of traffic within that cell and avoid inter-cell interference technology is being discussed for the new ATSC3.0, they with neighboring cells. New groups of sites are then all have one thing in common, the need for higher data installed to fill in the gaps. The smaller cells allow for a rates and more channel capacity. Broadcasters will greater level of frequency re-use providing more channels become “Bit Managers” knowing that more power per unit coverage area. equates to higher quality of service (QoS). With broad industry consensus, assumptions can be made about next Although the method will be different, the idea of future generation systems. In general they will be based on proofing a high power broadcast antenna in anticipation orthogonal frequency division multiplexing (OFDM) of next generation broadcast requirements should be synchronous single frequency networks (SFN) limited considered. In any of the proposed next generation within the current coverage footprint as defined by the systems, the digital bandwidth is not limited by the FCC and will have the flexibility to support capacity number of users, but by the data rate supported within a growth. As a result of post-auction repack there is likely given carrier to noise ratio (C/N). Increasing the capacity to be more co-located channel sharing requiring is not done by reducing the traffic, but by increasing the broadband antenna systems with the central high power amount of throughput that can be delivered. -
Theory on the Propagation of UHF Radio Waves in Coal Mine Tunnels
Theory of the Propagation of UHF Radio Waves in Coal Mine Tunnels ALFRED G. EXSLIE, ROBERT L. LAGACE, MEMBER, IEEE, AND PETER F. STRONG Abstract-The theoretical study of WFradio communication in coal mines, with particular reference to the rate of loss of signal strength along a tunnel, and from one tunnel to another around a comer is the concern of this -paper. - Of prime interest are the nature ....... .......-.. of the propagation mechanism and the prediction of the radio ....... ...... frequency that propagates with the smallest loss. The theoretical results are compared with published measurements. This work was Fig. 1. Wave guide geometry. part of an investigation of new ways to reach and extend two-way communications to the key individuals who are highly mobile within the sections and haulageways of coal mines. ~orkby AIarcatili and Schmeltzer r2] and by Glaser [3], which applies to waveguides of circular and parallel-plate INTRODUCTION geometry in a medium of uniform dielectric constant. We present in the body of the paper the main features of the T FREQUENCIES in the range of 200-4000 MHz propagation of UHF waves in tunnels. Details of the A the rock and coal bounding a coal mine tunnel act as derivations are contained in the accompanying appendices. relatively low-loss dielectrics with dielectric constants in the range 5-10. Under these conditions a reasonable THE FUXDARIEXTAL (1,l) WAVEGUIDE MODES hypothesis is that transmission takes the form of wave- guide propagation in a tunnel, since the wavelengths of The propagation modes with the lowest attenuation the UHF waves are smaller than the tunnel dimensions.