DOCSLIB.ORG

FY 1990 Technical Progress Report

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
FY 1990 Technical Progress Report INSTITUTE FOR TELECOMMUNICATION SCIENCES OF THE NATIONAL TELECOMMUNICATIONS AND INFORMATION ADMINISTRATION ANNUAL TECHNICAL PROGRESS REPORT 1990 For the Period October 1, 1989 through September 30, 1990 NATIONAL TELECOMMUNICATIONS AND INFORMATION ADMINISTRATION ADMINISTRATOR Deputy Administrator Office of Policy Coordination and Management Office of the Office of Office of Chief Counsel Intern at Iona I AffaIrs Congressional Affairs Office of Office of Institute fo r Office of Telecommun !cations Spectrum Telecom m u n Ica tion Pol icy Anal ysis Applications Management Sciences and Development Cover Photograph by Kenneth Spies ITS ANNUAL TECHNICAL PROGRESS REPORT 1990 For the Period October 1, 1989 through September 30, 1990 U.S. DEPARTMENT OF COMMERCE Robert A. Mosbacher, Secretary Janice Obuchowski, Assistant Secretary for Communications and Information THE ITS MISSION IT� cas f\�ltnechiefresearch �ha engineering arm • �!so serves a principal Federal · . of me f\jatiqn�l Telecommunications·· · and ·resource . · foe ... as?iSt�nc� • in·. solving ln�qrrn uory t\9ministration,thelnstitutej()r . tei�C?fl1n1UI1iBatiqn. probt�ms . of other � \ · Tele�om.rnunication· ... $ iences · .· (IT.�) Ff3(ieral... ��enci�s. ·. stgte and· · ••loca.l � • .· . · ·· ·· . · . · . ··••··�upport�l'\d£l)inistr<3ti?nteleyornmuni�<3tion.• goyernments, private•·· qorporgtions .•.anci ••··.··Q· �jectives �uch·�s enh<3n9ed···domestic a?S.()Ciatipns, and·· international irnpr ve(j · . .tna�e \ () · : �()mPetiti�f'l•• . .• f?re!gn .. Qrganiz�tion�; .. oppqrtul'tities f()r Y:S.t�lecortln1UI"lic tion. � : •. use firms. �nd. rnoreefficlentaf1d effe.ctive· . · . ·. · · · · qtthe.radiofreg!Jency sp�qtrum. · CONTENTS Page Overview vi Organization Chart ix Spectrum Use Analysis 1 Telecommunication Standards Development 15 Telecommunication Systems Performance 29 Telecommunication Systems Planning 45 Applied Research 53 ITS Tools and Facilities 61 ITS Projects List 65 ITS Publications for Fiscal Year 1990 71 ITS Publications Cited in This Report 75 v OVERVIEW The Institute for Telecommunication Sciences (ITS), located in Boulder, Colorado, is the chief research and BENEFITS engineering arm of the National Telecommunications and Information Administration (NTIA), U.S. The Institute's work significantly benefits both the Department of Commerce. ITS employs approximately public and private sectors in several areas including: 100 permanent program staff. Many of these employees Spectrum utilization bring substantial engineering and scientific backgrounds • and skills to our technically oriented programs. Indeed, Optimizing Federal spectrum allocation 50% of our employees are electronics engineers, 8% methods, identifying available frequencies and are mathematicians, 4% are physicists, 5% are computer potential interference through fi eld scientists, and 4% are computer programers. During measurements, and promoting technology FY 1990, ITS support consisted of $3.0 M of direct advances aid in more efficient and effective use fu nding from Commerce and $8.1 Min work sponsored of the scarce spectrum resource by other Federal agencies. Telecommunication negotiations • Developing negotiation support tools such as ACTIVITIES interference prediction programs and providing expert technical leadership improve the In achieving its mission, the Institute performs state­ preparation for, and conduct of, of-the-art telecommunication research, planning, and telecommunication negotiations at various engineering in each of the following functional areas: international conferences Spectrum Use Analysis • International trade Performing technical analyses of radio usage in • Promulgating broadly-based, nonrestrictive selected frequency bands and preparing U.S. international telecommunication standards helps technical positions for use at international to remove technical barriers to U.S. export of spectrum allocation conferences telecommunication equipment and services Telecommunication Standards Development • Domestic competition • Contributing to and developing Federal national Developing user-oriented, technology­ and international telecommunication standards independent methods of specifying and measuring telecommunication performance gives Telecommunication Systems Performance • users a practical way of comparing competing Forecasting how individual communication equipment and services elements will perform together and then testing them in a laboratory or operational environment National defense • Improving defense network operation and Telecommunication Systems Planning • management, enhancing survivability, expanding Relating needs of end users to the capabilities of network interconnection and interoperation, and a planned network improving planning fo r emergency communications restoral contribute to the Applied Research • strength and cost effectiveness of U.S. national Modeling the way radio waves travel from point defense forces to point in various frequency bands and evaluating the way information is carried by radio Technology transfer • signals, including modulation and coding Making available Institute technology evaluations and application studies hastens and expands the beneficial use of research results for industry in meeting specific user telecommunication needs vi The Executive Office handles the Institute's budget OUTPUTS and program planning functions as well as interacts with various administrative offices within other parts Major outputs of the Institute's research and of Commerce to achieve its payroll, procurement, engineering activities include personnel, facilities management, civil affairs, and publications requirements. Engineering tools and analysis • Predictions of transmission media conditions and equipment performance; test design and data analysis computer programs; complete laboratory and field tests of experimental and operational IDSTORY equipment, systems, or networks ITS had its organizational beginning during the 1940's Standards, guidelines, and procedures as, first, the Interservice Radio Propagation • Contributions to and development of national Laboratory and then later as the Central Radio and international standards in such areas as Propagation Laboratory (CRPL), each located within network interconnection and interoperation, the Commerce Department's National Bureau of performance evaluation, and information Standards. In 1965, CRPL was transferred to the protection Environmental Science Services Administration and given a new name---Institute for Telecommunication Research results Sciences and Aeronomy (ITSA). In 1967, ITS and the • Models for electromagnetic wave propagation, "A" organization were split. ITS was transferred into noise, and interference characterization the newly formed Office of Telecommunications (OT). Finally, under the President's Reorganization Act #1 Expert services of 1977, OT and the Office of Telecommunications • Training courses and workshops to communicate Policy merged to form NTIA. Since that time, ITS technology advances and applications to industry has been responsible for performing and Government users telecommunication research programs within NTIA and for providing technical engineering support to other elements of NTIA as well as to other agencies on a reimbursable basis. ORGANIZATION To carry out its activities, ITS is divided organizationally into two main program divisions-­ Spectrum Research and Analysis, and Systems and Networks Research and Analysis--and an Executive Office to handle administrative matters. Each of the program divisions is further divided into functionally oriented groups. Work performed by the Spectrum Division involves analyses directed toward understanding radio wave behavior at various frequencies and determining methods to enhance spectrum utilization. The Systems and Networks Division focuses on assessing and improving the performance of Government and private sector telecommunication networks, developing domestic and international telecommunication standards for telecommunication networks, and evaluating new technologies for application to future needs. Activities carried out within the two divisions are complementary and often synergistic. Janice Obuchowski Assistant Secretary for Communications and Information vii SPONSORS The activities of the Institute are undertaken through a combination of Commerce-sponsored and other-agency­ sponsored programs. NTINITS policy provides that other-agency-sponsored work results in contributions to and reinforcement of NTIA's overall program and is directed toward supporting Commerce goals. Various Army, Air Force, Navy, and other Department of Defense (DoD) components provide the majority of ITS' other-agency funding. Non-DoD sponsors typically include the Department of Transportation, the U.S. Information Agency, and the Department of Agriculture. Because of its centralized Federal position, ITS is able to provide a cost-effective, expert resource that does not require duplication throughout many Federal agencies. ITS Funding Sources FY 90 Other Federal Agencies 70% NT IA 30% Scientific research and engineering are critical to continued U.S. leadership in the provision of telecommunications and information equipment and services. In the pages that follow, this annual technical progress report summarizes specific FY 1990 technical DISCLAIMER contributions made by ITS that have significance for the public and private sectors. Certain commercial equipment and software products are identified in this report to adequately describe
Load more

Recommended publications
  • Development of Epstein-Peterson Method- Based Approach for Computing Multiple Knife Edgediffraction Loss As a Function of Refractivity Gradient
    Journal of Multidisciplinary Engineering Science and Technology (JMEST) ISSN: 2458-9403 Vol. 6 Issue 9, September - 2019 Development Of Epstein-Peterson Method- Based Approach For Computing Multiple Knife Edgediffraction Loss As A Function Of Refractivity Gradient Akaninyene B. Obot1 Ukpong,Victor Joseph2 Department of Electrical/Electronic and Computer Department of Electrical/Electronic and Computer Engineering, University of Uyo, AkwaIbom, Nigeria Engineering, University of Uyo, AkwaIbom, Nigeria Kalu Constance3 Department of Electrical/Electronic and Computer Engineering, University of Uyo, AkwaIbom, Nigeria [email protected] Abstract— In this paper, the development of I. INTRODUCTION Epstein-Peterson method-based approach for Radio wave propagation over irregular computing multiple knife edge diffraction loss as a function of refractivity gradient. Specifically, the terrain consisting of mountain, buildings, hills study utilized Epstein Peterson diffraction loss and even trees and other high rising methodology alongside the International obstructions is of great concern to Telecommunication Union (ITU) knife edge communication network designers [1,2,3,4]. approximation model to compute multiple knife When a wireless signal is propagated over a edge diffraction loss as a function of refractivity gradient. Analytical expression for the long distance, the signal may get distorted and determination of obstacles height, the earth bulge attenuated due to obstacles along its path. This and the effective obstruction height were modeled causes the signal to be reflected, absorbed in terms of the refractivity gradient (∆). A case scattered or diffracted. Diffraction occurs when study of 10 knife edge obstructions located in a a wireless signal encounter obstacles in its path communication link with a path length of 36km was used as a numerical example to demonstrate [6,7,8,9,10].
    [Show full text]
  • Hitless Space Diversity STL Enables IP+Audio in Narrow STL Bands
    Hitless Space Diversity STL Enables IP+Audio in Narrow STL Bands Presented at the 2005 National Association of Broadcasters Annual Convention Broadcast Engineering Conference Session "HD Radio™ Technology" April 17, 2005 Howard Friedenberg, Senior RF Engineer Sunil Naik, Director of Engineering Moseley Associates, Inc. Santa Barbara, CA, USA Contacts: [email protected] [email protected] www.moseleysb.com (805) 968-9621 Hitless Space Diversity STL Enables IP+Audio in Narrow STL Bands Howard Friedenberg Moseley Associates, Inc. Santa Barbara, CA, USA ABSTRACT In this paper we will be looking at issues that affect HD Radio™ poses a new challenge to STLs, requiring STL transmission reliability as they pertain to newer the ability to transport an Ethernet channel at 300 kbps high rate applications. Path reliability and keeping your along side a 44.1 kHz sampled AES digital stereo pair station on-air is the name of the game. Fading and ultimately fit them into a single 300 kHz STL mitigation techniques must be implemented to handle channel. This requirement is only possible with latest these higher level data packing modulations effectively generation digital STLs operating with very high against channel impairments and to maintain consistent efficiency, e.g. 128 QAM. As QAM rates are increased, path integrity. Receive site frequency and space also is the sensitivity to multipath. “Hitless” switching diversity techniques are a major tool in battling these enables real time space diversity antenna systems to effects. We’ll describe how to properly implement STL combat instantaneous multipath fading on microwave diversity techniques with a “hitless” transfer switch. paths that commonly occurs in Spring and Fall seasons.
    [Show full text]
  • Digital Radio-Relay Systems
    - iii - TABLE OF CONTENTS Page CHAPTER 1 - INTRODUCTION........................................................................................ 1 1.1 INTENT OF HANDBOOK ..................................................................................... 1 1.2 EVOLUTION OF DIGITAL RADIO-RELAY SYSTEMS .................................... 2 1.3 DIGITAL RADIO-RELAY SYSTEMS AS PART OF DIGITAL TRANSMISSION NETWORKS............................................................................. 3 1.4 GENERAL OVERVIEW OF THE HANDBOOK .................................................. 5 1.5 OUTLINE OF THE HANDBOOK.......................................................................... 5 CHAPTER 2 - BASIC PRINCIPLES .................................................................................. 7 2.1 DIGITAL SIGNALS, SOURCE CODING, DIGITAL HIERARCHIES AND MULTIPLEXING .......................................................................................... 7 2.1.1 Digitization (A/D conversion) of analogue voice signals ........................... 7 2.1.2 Digitization of video signals........................................................................ 8 2.1.3 Non voice services, ISDN and data signals ................................................. 8 2.1.4 Multiplexing of 64 kbit/s channels .............................................................. 8 2.1.5 Higher order multiplexing, Plesiochronous Digital Hierarchy (PDH) ........ 8 2.1.6 Other multiplexers ......................................................................................
    [Show full text]
  • Microwave Radio Transmission Design Guide
    Microwave Radio Transmission Design Guide Second Edition page i Finals 06-17-09 10:39:14 For a listing of recent titles in the Artech House Microwave Library, turn to the back of this book. page ii Finals 06-17-09 10:39:14 Microwave Radio Transmission Design Guide Second Edition Trevor Manning page iii Finals 06-17-09 10:39:14 Library of Congress Cataloging-in-Publication Data A catalog record for this book is available from the U.S. Library of Congress. British Library Cataloguing in Publication Data A catalogue record for this book is available from the British Library. ISBN-13: 978-1-59693-456-6 Cover design by Igor Valdman 2009 ARTECH HOUSE 685 Canton Street Norwood, MA 02062 All rights reserved. Printed and bound in the United States of America. No part of this book may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, or by any information storage and retrieval system, without permission in writing from the publisher. All terms mentioned in this book that are known to be trademarks or service marks have been appropriately capitalized. Artech House cannot attest to the accuracy of this information. Use of a term in this book should not be regarded as affecting the validity of any trademark or service mark. 10 987654321 page iv Finals 06-17-09 10:39:14 Contents Foreword xiii Preface xv 1 Introduction 1 1.1 History of Wireless Telecommunications 2 1.2 What Is Microwave Radio? 3 1.2.1 Microwave Fundamentals 3 1.2.2 RF Spectrum 4 1.2.3 Safety of Microwaves 5 1.2.4 Allocation
    [Show full text]
  • Aeronautical Radio Communication Systems and Networks
    JWBK149-FM JWBK149-Stacey February 9, 2008 21:57 Aeronautical Radio Communication Systems and Networks Dale Stacey John Wiley & Sons, Ltd iii JWBK149-FM JWBK149-Stacey February 9, 2008 21:57 ii JWBK149-FM JWBK149-Stacey February 9, 2008 21:57 Aeronautical Radio Communication Systems and Networks i JWBK149-FM JWBK149-Stacey February 9, 2008 21:57 ii JWBK149-FM JWBK149-Stacey February 9, 2008 21:57 Aeronautical Radio Communication Systems and Networks Dale Stacey John Wiley & Sons, Ltd iii JWBK149-FM JWBK149-Stacey February 9, 2008 21:57 Copyright C 2008 John Wiley & Sons Ltd, The Atrium, Southern Gate, Chichester, West Sussex PO19 8SQ, England Telephone (+44) 1243 779777 Email (for orders and customer service enquiries): [email protected] Visit our Home Page on www.wiley.com All Rights Reserved. No part of this publication may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, scanning or otherwise, except under the terms of the Copyright, Designs and Patents Act 1988 or under the terms of a licence issued by the Copyright Licensing Agency Ltd, 90 Tottenham Court Road, London W1T 4LP, UK, without the permission in writing of the Publisher. Requests to the Publisher should be addressed to the Permissions Department, John Wiley & Sons Ltd, The Atrium, Southern Gate, Chichester, West Sussex PO19 8SQ, England, or emailed to [email protected], or faxed to (+44) 1243 770620. Designations used by companies to distinguish their products are often claimed as trademarks. All brand names and product names used in this book are trade names, service marks, trademarks or registered trademarks of their respective owners.
    [Show full text]
  • Bibliography on Tropospheric Propagation of Radio Waves
    National Bureau of Standards Library, M.W. Bldg APR 8 1965 ^ecknical ^iote 304 BIBLIOGRAPHY ON TROPOSPHERIC PROPAGATION OF RADIO WAVES WILHELM NUPEN mm U. S. DEPARTMENT OF COMMERCE NATIONAL BUREAU OF STANDARDS THE NATIONAL BUREAU OF STANDARDS The National Bureau of Standards is a principal focal point in the Federal Government for assuring maximum application of the physical and engineering sciences to the advancement of technology in industry and commerce. Its responsibilities include development and maintenance of the national stand- ards of measurement, and the provisions of means for making measurements consistent with those standards; determination of physical constants and properties of materials; development of methods for testing materials, mechanisms, and structures, and making such tests as may be necessary, particu- larly for government agencies; cooperation in the establishment of standard practices for incorpora- tion in codes and specifications; advisory service to government agencies on scientific and technical problems; invention and development of devices to serve special needs of the Government; assistance to industry, business, and consumers in the development and acceptance of commercial standards and simplified trade practice recommendations; administration of programs in cooperation with United States business groups and standards organizations for the development of international standards of practice; and maintenance of a clearinghouse for the collection and dissemination of scientific, tech- nical, and engineering information. The scope of the Bureau's activities is suggested in the following listing of its four Institutes and their organizational units. Institute for Basic Standards. Electricity. Metrology. Heat. Radiation Physics. Mechanics. Ap- plied Mathematics. Atomic Physics. Physical Chemistry. Laboratory Astrophysics.* Radio Stand- ards Laboratory: Radio Standards Physics; Radio Standards Engineering.** Office of Standard Ref- erence Data.
    [Show full text]
  • Microwave Path Engineering April 2005
    Microwave Path Engineering USTTI Course 19-311 September 24, 2019 Course Outline 1. Microwave Components 2. RF Propagation 3. Link Budget 4. Reliability 5. Interference Analysis © 2014 CommScope, Inc. 2 Microwave Diagram Antenna Antenna Waveguide Waveguide Radio Radio © 2014 CommScope, Inc. 3 Radio Equipment © 2014 CommScope, Inc. 4 Radio Equipment Theoretical Error Performance of Digital Modulation Schemes -2 Excludes FEC Improvement • “Waterfall” -3 Curves -4 -5 -6 -7 -8 Log BER Probability (e.g. = -6 BER) 10-6 -9 BPSK -10 -11 4 PSK QPSK 8 PSK 4 QAM 16 QAM 64 QAM 256 QAM -12 5 10 15 20 25 30 35 40 C/N (RF Carrier-to-Noise Ratio) dB © 2014 CommScope, Inc. 5 Radio Equipment • Threshold – Minimum receiver input level below which BER becomes excessive due to thermal noise • The 10-6 BER threshold is called the Static Threshold • The 10-3 BER threshold is called the Dynamic or Outage Threshold • Oversaturation Level – Maximum receiver input level above which BER becomes excessive due to overdriving electronics into saturation (distortion) • Receiver can operate with low error rate between threshold and oversaturation dynamic range © 2014 CommScope, Inc. 6 Radio Equipment - Data Rates of Common Interfaces North American Digital Hierarchy Designation Data Rate DS0's (# of VC) DS1 (T1) 1.544 Mb/s 24 DS2 (T2) 6.312 Mb/s 96 DS3 (T3) 45 Mb/s 672 3xDS3 135 Mb/s 2016 DS5 (T5) 400 Mb/s 5760 European Digital Hierarchy Designation Data Rate DS0's (# of VC) E1 2.048 Mb/s 32 E2 8.448 Mb/s 128 E3 34.4 Mb/s 512 E4 139.3 Mb/s 2048 E5 565 Mb/s 8192 Optical Signal Hierarchy SONET Designation SDH Designation Data Rate STS-3 STM-1 155.52 Mb/s STS-12 STM-4 622.08 Mb/s STS-48 STM-16 2488.32 Mb/s STS-192 STM-64 9953.28 Mb/s © 2014 CommScope, Inc.
    [Show full text]
  • Radiowave Propagation Information for Designing Terrestrial Point-To-Point Links Iii
    International Telecommunication Union Edition 2008 Handbook RADIOWAVE PROPAGATION INFORMATION FOR DESIGNING TERRESTRIAL POINT-TO-POINTS LINKS Edition 2008 RADIOWAVE PROPAGATION INFORMATION FOR DESIGNING TERRESTRIAL POINT-TO-POINTS LINKS FOR DESIGNING TERRESTRIAL POINT-TO-POINTS INFORMATION PROPAGATION RADIOWAVE *33616* Printed in Switzerland International Geneva, 2009 RRadiocommunicationadiocommunication BBureauureau Telecommunication ISBN 92-61-12771-1 Union Photo credits: Shutterstock Handbook THE RADIOCOMMUNICATION SECTOR OF ITU The role of the Radiocommunication Sector is to ensure the rational, equitable, efficient and economical use of the radio-frequency spectrum by all radiocommunication services, including satellite services, and carry out studies without limit of frequency range on the basis of which Recommendations are adopted. The regulatory and policy functions of the Radiocommunication Sector are performed by World and Regional Radiocommunication Conferences and Radiocommunication Assemblies supported by Study Groups. Inquiries about radiocommunication matters Please contact: ITU Radiocommunication Bureau Place des Nations CH -1211 Geneva 20 Switzerland Telephone: +41 22 730 5800 Fax: +41 22 730 5785 E-mail: [email protected] Web: www.itu.int/itu-r Placing orders for ITU publications Please note that orders cannot be taken over the telephone. They should be sent by fax or e-mail. ITU Sales and Marketing Division Place des Nations CH -1211 Geneva 20 Switzerland Fax: +41 22 730 5194 E-mail: [email protected] The Electronic Bookshop
    [Show full text]
  • The Recent Advancement in Unmanned Aerial Vehicle Tracking Antenna: a Review
    sensors Review The Recent Advancement in Unmanned Aerial Vehicle Tracking Antenna: A Review Anabi Hilary Kelechi 1, Mohammed H. Alsharif 2,* , Damilare Abdulbasit Oluwole 1, Philip Achimugu 3, Osichinaka Ubadike 1, Jamel Nebhen 4, Atayero Aaron-Anthony 5 and Peerapong Uthansakul 6,* 1 Department of Aerospace Engineering, Faculty of Air Engineering, AirForce Institute of Technology, Kaduna 800282, Nigeria; hk.anabi@afit.edu.ng (A.H.K.); damilareoluwole@afit.edu.ng (D.A.O.); ocubadike@afit.edu.ng (O.U.) 2 Department of Electrical Engineering, College of Electronics and Information Engineering, Sejong University, 209 Neungdong-ro, Gwangjin-gu, Seoul 05006, Korea 3 Department of Computer Science, Faculty of Computing, AirForce Institute of Technology, Kaduna 800282, Nigeria; p.achimugu@afit.edu.ng 4 College of Computer Engineering and Sciences, Prince Sattam bin Abdulaziz University, P.O. Box 151, Alkharj 11942, Saudi Arabia; [email protected] 5 Department of Electrical and Information Engineering, Covenant University, Ota 112233, Ogun State, Nigeria; [email protected] 6 School of Telecommunication Engineering, Suranaree University of Technology, Nakhon Ratchasima 30000, Thailand * Correspondence: [email protected] (M.H.A.); [email protected] (P.U.) Abstract: Unmanned aerial vehicle (UAV) antenna tracking system is an electromechanical com- ponent designed to track and steer the signal beams from the ground control station (GCS) to the Citation: Kelechi, A.H.; Alsharif, airborne platform for optimum signal alignment. In a tracking system, an antenna continuously M.H.; Oluwole, D.A.; Achimugu, P.; tracks a moving target and records their position. A UAV tracking antenna system is susceptible Ubadike, O.; Nebhen, J.; to signal loss if omnidirectional antenna is deployed as the preferred design.
    [Show full text]
  • Radiowave Propagation August 17, 2018 1 / 52 I
    Terrain Reflection and Diffraction, Part One 1 UHF and VHF paths near the ground 2 Propagation over a plane Earth 3 Fresnel zones Levis, Johnson, Teixeira (ESL/OSU) Radiowave Propagation August 17, 2018 1 / 52 I. UHF and VHF paths near the ground In many applications communications are influenced by reflections from the Earth surface Particular problem when antenna gains are small and receivers are near the ground In Chapter 7 we will study the direct + Earth reflections mechanism and also terrain diffraction The Earth surface also plays a role in groundwave propagation (Chapter 9) but this applies mainly at lower than VHF frequencies Since ionospheric propagation is also negligible for VHF and higher freqencies, direct + Earth reflections and terrain diffraction are the main mechanism for these frequencies over medium distances Tropospheric scatter applies at very long distances Consideration of \multipath environments" in Chapter 8 Levis, Johnson, Teixeira (ESL/OSU) Radiowave Propagation August 17, 2018 2 / 52 We will learn basic methods for predicting propagation over a specified terrain path Primarily applied to assess antenna heights needed to maintain communications for various values of κ Used in designing line-of-sight UHF and SHF point-to-point links Numerical methods are also now being applied here; we will learn a little about these as well Levis, Johnson, Teixeira (ESL/OSU) Radiowave Propagation August 17, 2018 3 / 52 II. Propagation over a plane Earth Begin by assuming the Earth surface to be planar (valid approximation for short distances
    [Show full text]
  • Propagation: Fundamentals and Models
    Tropospheric scatter Diffraction Line of sight Propagation: fundamentals and models Carol Wilson, CSIRO Chairman ITU-R Study Group 3 (Radiowave Propagation) 5th Summer School in Spectrum Management for Radio Astronomy 2 – 6 March 2020, Stellenbosch Australia’s National Science Agency Outline of presentation • Introduction – Who creates RFI? • Why propagation is important • Mechanisms of radiowave propagation and prediction methods • Types of models • Software • Conclusion Who creates the interference that ruins my observations? RFI from meteorological systems Home weather station 433 MHz Met Bureau radar 5.6 GHz Weather sensing from space: 10.6, 19, 24, 31 and 36 GHz RFI from transportation Keyless entry 315 MHz Garage door opener 27 MHz Carpark entry sensor 920 MHz Programmable road signs 18 GHz Traffic helicopter 410 MHz E-tags 5.8 GHz Police speed radar 10.5 GHz Collision avoidance radar 76 GHz RFI from aircraft systems Navigation aids 126.6 MHz Radionavigation 1.2 and 2.9 GHz Air traffic control 118.7 and 129.9 MHz Instrument Landing System 109.5 MHz RFI from giving a talk at a conference Wireless microphone 550 MHz Lunchtime!! Microwave oven 2.4 GHz RFI from consumer communications 3G phone 2.1 GHz* 4G phone 700 MHz* 5G phone 3.5 GHz* Bluetooth 2.4 GHz WiFi 2.4 and 5.8 GHz * And others!! RFI from broadcasting FM radio 88 – 108 MHz VHF TV 174 – 230 MHz UHF TV 526 – 694 MHz Electronic News Gathering 2.3 GHz Satellite broadcasting 12 GHz We are the “other users of spectrum” Urban, suburban and small towns have an increasing amount of radio system usage and electrical appliances.
    [Show full text]
  • Performance Analysis of Fixed Wimax in Metropolitan Area
    International Journal of Electronics and Communication Engineering. ISSN 0974-2166 Volume 5, Number 3 (2012), pp. 331-341 © International Research Publication House http://www.irphouse.com Performance Analysis of Fixed WiMAX in Metropolitan Area Md. Shah Alam and Kazi Tanvir Ahmmed Department of Applied Physics, Electronics and Communication Engineering, University of Chittagong, Chittagong-4331, Bangladesh E-mail: [email protected], [email protected] Abstract Fixed WiMAX is being deployed worldwide, and the networks are increasing in size. Measurements have been performed, but the amount of measurements are few and do therefore not demonstrate performance in a real life deployment. We have performed analyses of the physical performance in a fixed WiMAX deployment. The analysis presented in this paper focus on received signal strength and signals to noise ratio. Keywords: Fixed WiMAX, Physical Analysis, RSSI, SNR, NMS. Introduction Broadband wireless is a technology that promises high-speed (minimally, several hundred kilo bits per second) data transmissions occurring within an infrastructure of more or less fixed points, including both stationary subscriber terminals and service provider base stations, which themselves constitute the hubs of the network [1]. Worldwide Interoperability for Microwave Access (WiMAX) is a broadband wireless access system which offers high throughput, great coverage, flexible Quality of Service (QoS) support and extensive security. WiMAX is certified by the WiMAX forum [2], which is a certification mark based on the IEEE 802.16 standard [3, 4] that pass conformity and interoperability tests. Two major way of accessibility is offered by WiMAX standard namely Fixed WiMAX (802.16d) and Mobile WiMAX (802.16e).
    [Show full text]