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- Herausgeber: John Wiley & Sons
- Kategorie: Wissenschaft und neue Technologien
- Sprache: Englisch
The first edition of Satellite Communications Systems Engineering (Wiley 2008) was written for those concerned with the design and performance of satellite communications systems employed in fixed point to point, broadcasting, mobile, radio navigation, data relay, computer communications, and related satellite based applications. This welcome Second Edition continues the basic premise and enhances the publication with the latest updated information and new technologies developed since the publication of the first edition. The book is based on graduate level satellite communications course material and has served as the primary text for electrical engineering Masters and Doctoral level courses in satellite communications and related areas. Introductory to advanced engineering level students in electrical, communications and wireless network courses, and electrical engineers, communications engineers, systems engineers, and wireless network engineers looking for a refresher will find this essential text invaluable.
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Table of Contents
Cover
Title Page
Copyright
List of Acronyms
Preface to Second Edition
Chapter 1: Introduction to Satellite Communications
1.1 Early History of Satellite Communications
1.2 Some Basic Communications Satellite System Definitions
1.3 Overview of Book Structure and Topics
References
Chapter 2: Satellite Orbits
2.1 Kepler's Laws
2.2 Orbital Parameters
2.3 Orbits in Common Use
2.4 Geometry of GSO Links
References
Problems
Chapter 3: Satellite Subsystems
3.1 Satellite Bus
3.2 Satellite Payload
References
Chapter 4: The RF Link
4.1 Transmission Fundamentals
4.2 System Noise
4.3 Link Performance Parameters
References
Problems
Chapter 5: Link System Performance
5.1 Link Considerations
5.2 Uplink
5.3 Downlink
5.4 Percent of Time Performance Specifications
References
Problems
Chapter 6: Transmission Impairments
6.1 Radiowave Frequency and Space Communications
6.2 Radiowave Propagation Mechanisms
6.3 Propagation Below About 3 GHz
6.4 Propagation Above About 3 GHz
6.5 Radio Noise
References
Problems
Chapter 7: Propagation Effects Modeling and Prediction
7.1 Atmospheric Gases
7.2 Clouds and Fog
7.3 Rain Attenuation
7.4 Depolarization
7.5 Tropospheric Scintillation
References
Problems
Chapter 8: Rain Fade Mitigation
8.1 Power Restoral Techniques
8.2 Signal Modification Restoral Techniques
8.3 Summary
References
Problems
Chapter 9: The Composite Link
9.1 Frequency Translation (FT) Satellite
9.2 On-Board Processing (OBP) Satellite
9.3 Comparison of FT and OBP Performance
9.4 Intermodulation Noise
9.5 Link Design Summary
References
Problems
Chapter 10: Satellite Communications Signal Processing
10.1 Analog Systems
10.2 Digital Baseband Formatting
10.3 Digital Source Combining
10.4 Digital Carrier Modulation
10.5 Summary
Reference
Problems
Chapter 11: Satellite Multiple Access
11.1 Frequency Division Multiple Access
11.2 Time Division Multiple Access
11.3 Code Division Multiple Access
References
Problems
Chapter 12: The Mobile Satellite Channel
12.1 Mobile Channel Propagation
12.2 Narrowband Channel
12.3 Wideband Channel
12.4 Multi-Satellite Mobile Links
References
Chapter 13: Spectrum Management in Satellite Communications
13.1 Spectrum Management Functions and Activities
13.2 Methods of Radio Spectrum Sharing
13.3 Spectrum Efficiency Metrics
References
Problems
Chapter 14: Interference Mitigation in Satellite Communications
14.1 Interference Designations
14.2 Modes of Interference for Satellite Services Networks
14.3 Interference Propagation Mechanisms
14.4 Interference and the RF Link
14.5 Coordination for Interference Mitigation
References
Problems
Chapter 15: High Throughput Satellites
15.1 Evolution of Satellite Broadband
15.2 Multiple Beam Antennas and Frequency Reuse
15.3 HTS Ground Systems Infrastructure
15.4 Satellite HTS and 5G
References
Appendix: Error Functions and Bit Error Rate
A.1 Error Functions
A.2 Approximation for BER
Index
End User License Agreement
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Guide
Cover
Table of Contents
Preface to Second Edition
Begin Reading
List of Illustrations
Chapter 1: Introduction to Satellite Communications
Figure 1.1 Communications via satellite in the telecommunications infrastructure.
Figure 1.2 The space segment for a communications satellite network.
Figure 1.3 Basic link parameters in the communications satellite link.
Figure 1.4 Satellite orbits.
Figure 1.5 Letter band frequency designations.
Figure 1.6 Frequency band designations by wavelength.
Chapter 2: Satellite Orbits
Figure 2.1 Forces acting on a satellite.
Figure 2.2 Kepler's First Law.
Figure 2.3 Kepler's Second Law.
Figure 2.4 Earth-orbiting satellite parameters.
Figure 2.5 Prograde and retrograde orbits.
Figure 2.6 Sidereal time.
Figure 2.7 GSO - geosynchronous earth orbit.
Figure 2.8 LEO - low earth orbit.
Figure 2.9 MEO – medium earth orbit.
Figure 2.10 HEO – highly elliptical earth orbit.
Figure 2.11 GSO look angles to satellite.
Figure 2.12 Earth station altitude.
Figure 2.13 Sign convention for longitude and lattitude.
Figure 2.14 Determination of azimuth angle condition.
Chapter 3: Satellite Subsystems
Figure 3.1 Communications via satellite.
Figure 3.2 Communications satellite subsystems.
Figure 3.3 Physical structure.
Figure 3.4 Despun platform on spin stabilized satellite.
Figure 3.5 GSO satellite stable points. (
Source: Pratt
[2]; reproduced by permission of John Wiley & Sons, Inc.)
Figure 3.6 Orbital control parameters for GSO satellites.
Figure 3.7 Tracking, telemetry, command, and monitoring (TTC&M).
Figure 3.8 Frequency translation transponder.
Figure 3.9 On-board processing transponder.
Chapter 4: The RF Link
Figure 4.1 Basic communications link.
Figure 4.2 Definition of wavelength.
Figure 4.3 Inverse square law of radiation.
Figure 4.4 Power flux density.
Figure 4.5 Antenna beamwidth.
Figure 4.6 Basic communications link.
Figure 4.7 Ku-band link parameters.
Figure 4.8 Receiver front end.
Figure 4.9 Noise Figure of device.
Figure 4.10 Equivalent noise circuit for an active device.
Figure 4.11 Equivalent noise circuit for a passive device.
Figure 4.12 Sources of receiver antenna noise.
Figure 4.13 Increase in antenna temperature due to atmospheric constituents (a) no rain, (b) rain.
Figure 4.14 Satellite receiver system and system noise temperature.
Figure 4.15 Sample calculation parameters for system noise temperature.
Figure 4.16 Satellite link parameters.
Chapter 5: Link System Performance
Figure 5.1 Satellite link parameters.
Figure 5.2 Fixed antenna size satellite link.
Figure 5.3 Fixed antenna gain links.
Figure 5.4 Fixed antenna gain, fixed antenna size link.
Figure 5.5 Basic satellite transponder parameters.
Figure 5.6 Power amplifier input/output transfer characteristic.
Figure 5.7 Percent of time performance.
Chapter 6: Transmission Impairments
Figure 6.1 Components of the atmosphere impacting space communications.
Figure 6.2 Radiowave propagation modes. (Source: Ippolito [1]; reproduced by permission of Van Nostrand Reinhold.)
Figure 6.3 Radiowave propagation mechanisms and their impact on the parameters of a communications signal. (Source: Ippolito [1]; reproduced by permission of Van Nostrand Reinhold.)
Figure 6.4 Examples of electron density distributions (from Hanson WB., “Structures of the Ionosphere” in Johnson, F.S. (ed.), Satellite Environment Handbook, Stanford University Press, 1965). (Source: Flock [4]. Reproduced by permission of NASA.)
Figure 6.5 Diurnal variations in TEC, mean monthly curves for 1967 to 1973 as obtained at Sagamore Hill, MA, USA (after Hawkins & Klobuchar, 1974). (Source: Flock [4]; reproduced by permission of NASA.)
Figure 6.6 Regions of ionospheric scintillation. (Source: ITU-R [3]; reproduced by permission of International Telecommunications Union.)
Figure 6.7 Faraday rotation angle as a function of operating frequency and TEC.
Figure 6.8 Ionospheric group delay as a function of operating frequency and TEC.
Figure 6.9 Dispersion for a pulse of width , transmitted through the ionosphere with a TEC level of . (Source: ITU-R [3]; reproduced by permission of International Telecommunications Union.)
Figure 6.10 Plane wave incident on a volume of spherical uniformly distributed water drops. (Source: Ippolito [1]; reproduced by permission of Van Nostrand Reinhold.)
Figure 6.11 Total path rain attenuation as a function of frequency and elevation angle location: Washington, DC, link availability: 99%.
Figure 6.12 Total path gaseous attenuation versus frequency for elevation angles from 5 to 30 degrees, location: Washington DC.
Figure 6.13 Specific attenuation for clouds as a function of frequency and temperature. (Source: ITU-R [11]; reproduced by permission of International Telecommunications Union.)
Figure 6.14 Total cloud attenuation as a function of frequency, for elevation angles from 5 to 30 degrees. (Source: ITU-R [11].)
Figure 6.15 Depolarization components for linearly polarized waves.
Figure 6.16 Canting angle for oblate spheroid rain drop.
Figure 6.17 Rain depolarization XPD as a function of frequency and elevation angle location: Washington, DC, link availability: 99%.
Figure 6.18 Rain and ice depolarization at 11.7 GHz. (Source: Ippolito [1]; reproduced by permission of Van Nostrand Reinhold.)
Figure 6.19 Rain and ice depolarization at 19 GHz. (Source: Ippolito [1]; reproduced by permission of Van Nostrand Reinhold.)
Figure 6.20 Scintillation on a satellite link for low elevation angles. (Source: Ippolito [1]; reproduced by permission of Van Nostrand Reinhold.)
Figure 6.21 Mean amplitude variance for clear weather conditions, at 2 and 30 GHz, as a function of elevation angle. (Source: Ippolito [1]; reproduced by permission of Van Nostrand Reinhold.)
Figure 6.22 Noise factor and brightness temperature from external sources. (Source: ITU-R [5]; reproduced by permission of International Telecommunications Union.)
Figure 6.23 Brightness temperature of the atmosphere for moderate clear sky conditions. (Source: ITU-R [5]; reproduced by permission of International Telecommunications Union.)
Figure 6.24 Brightness temperature of the atmosphere for moderate clear sky conditions – expanded scale; 1 to 60 GHz. (Source: ITU-R [5]; reproduced by permission of International Telecommunications Union.)
Figure 6.25 Noise temperature as a function of total path attenuation, for mean path temperatures of 270, 275, and 280 K.
Figure 6.26 Slobin cloud regions. (Source: Slobin [10]; reproduced by permission of American Geophysical Union.)
Figure 6.27 Cumulative distributions of zenith sky temperature for four locations from the Slobin cloud model. (Source: Ippolito [1]; reproduced by permission of Van Nostrand Reinhold.)
Figure 6.28 Extraterrestrial noise sources. (Source: ITU-R [5]; reproduced by permission of International Telecommunications Union.)
Figure 6.29 Radio sky temperature at 408 MHz. (Source: ITU-R [5]; reproduced by permission of International Telecommunications Union.)
Figure 6.30 Radio sky temperature at 408 MHz. (Source: ITU-R [5]; reproduced by permission of International Telecommunications Union.)
Figure 6.31 The radio sky at 250 MHz in the region around the geostationary orbital arc. (Source: Ippolito [1]; reproduced by permission of Van Nostrand Reinhold.)
Figure 6.32 Power flux density for quiet and active sun. (Source: Ippolito [28]; reproduced by permission of NASA.)
Chapter 7: Propagation Effects Modeling and Prediction
Figure 7.1 Variation of water vapor with zenith height. (Source: Ippolito [3]; reproduced by permission of NASA.)
Figure 7.2 Gaseous attenuation layer geometry. (Source: ITU-R P.676 [2]; reproduced by permission of International Telecommunications Union.)
Figure 7.3 Specific attenuation due to atmospheric gases. (Source: ITU-R P.676 [2]; reproduced by permission of International Telecommunications Union.)
Figure 7.4 Zenith attenuation due to atmospheric gases. (Source: ITU-R P.676 [2]; reproduced by permission of International Telecommunications Union.)
Figure 7.5 Normalized total columnar content of cloud liquid water exceeded for 20% of the year, in kg/m
2
. (Source: ITU-R P.840-3 [10]; reproduced by permission of International Telecommunications Union.)
Figure 7.8 Normalized total columnar content of cloud liquid water exceeded for 1% of the year, in kg/m
2
. (Source: ITU-R P.840-3 [10]; reproduced by permission of International Telecommunications Union.)
Figure 7.9 Slobin cloud regions. (Source: Slobin [9]; reproduced by permission of American Geophysical Union.)
Figure 7.10 Zenith cloud attenuation at 30 GHz from the Slobin cloud model. (Source: Slobin [9]; reproduced by permission of American Geophysical Union.)
Figure 7.11 Cumulative distributions of zenith cloud attenuation at four locations, from the Slobin cloud model. (Source: Slobin [9]; reproduced by permission of American Geophysical Union.)
Figure 7.12 Yearly average 0°C isotherm height, h
o
, above mean sea level, in km. (Source: ITU-R P.839-3 [18]; reproduced by permission of International Telecommunications Union.)
Figure 7.13 Slant path through rain. (Source: ITU-R 618-8 [15]; reproduced by permission of International Telecommunications Union.)
Figure 7.14 Rain intensity exceeded for 0.01% of an average year – area 1. (Source: ITU-R P.837-4 [16]; reproduced by permission of International Telecommunications Union.)
Figure 7.19 Rain intensity exceeded for 0.01% of an average year – area 6. (Source: ITU-R P.837-4 [16]; reproduced by permission of International Telecommunications Union.)
Figure 7.20 Regression coefficients k
H
and α
H
for the calculation of k and α. (Source: ITU-R P.838-3 [17]; reproduced by permission of International Telecommunications Union.)
Figure 7.23 Global model rain climate zones for Europe and Africa. (Source: Crane [22]; reproduced by permission of John Wiley & Sons, Inc.)
Figure 7.22 Global model rain climate zones for North and South America. (Source: Crane [22]; reproduced by permission of John Wiley & Sons, Inc.)
Figure 7.26 Global model rain climate zones for Asia. (Source: Crane [22]; reproduced by permission of John Wiley & Sons, Inc.)
Figure 7.24 Global model rain climate zones for North America. (Source: Crane [22]; reproduced by permission of John Wiley & Sons, Inc.)
Figure 7.25 Global model rain climate zones for Western Europe. (Source: Crane [22]; reproduced by permission of John Wiley & Sons, Inc.)
Figure 7.27 Rain height for the global rain attenuation model. (Source: Crane [22]; reproduced by permission of John Wiley & Sons, Inc.)
Figure 7.21 Regression coefficients k
V
and α
V
for the calculation of k and α. (Source: ITU-R P.838-3 [17]; reproduced by permission of International Telecommunications Union.)
Figure 7.28 T-Matrix Representation for a Dual-polarized System.
Chapter 8: Rain Fade Mitigation
Figure 8.1 Antenna beam diversity options. (Source: Ippolito [1]; reproduced by permission of © 1986 Van Nostrand Reinhold.)
Figure 8.2 Gain improvement between antenna beam options. (Source: Ippolito [1]; reproduced by permission of © 1986 Van Nostrand Reinhold.)
Figure 8.3 Closed loop uplink power control. (Source: Ippolito [1]; reproduced by permission of © 1986 Van Nostrand Reinhold.)
Figure 8.4 Open loop uplink power control: downlink control signal. (Source: Ippolito [1]; reproduced by permission of © 1986 Van Nostrand Reinhold.)
Figure 8.6 Open loop uplink power control: radiometer control signal. (Source: Ippolito [1]; reproduced by permission of © 1986 Van Nostrand Reinhold.)
Figure 8.5 Open loop uplink power control: beacon control signal. (Source: Ippolito [1]; reproduced by permission of © 1986 Van Nostrand Reinhold.)
Figure 8.7 Site diversity concept. (Source: Ippolito [1]; reproduced by permission of © 1986 Van Nostrand Reinhold.)
Figure 8.8 Definition of diversity gain. (Source: Ippolito [1]; reproduced by permission of © 1986 Van Nostrand Reinhold.)
Figure 8.9 Dependence of diversity gain on site separation (idealized). (Source: Ippolito [1]; reproduced by permission of © 1986 Van Nostrand Reinhold.)
Figure 8.10 Diversity gain and single terminal attenuation (idealized). (Source: Ippolito [1]; reproduced by permission of © 1986 Van Nostrand Reinhold.)
Figure 8.11 Definition of diversity improvement. (Source: Ippolito [1]; reproduced by permission of © 1986 Van Nostrand Reinhold.)
Figure 8.12 Site diversity measurements at 11.6 GHz in West Virginia. (Source: Ippolito [1]; reproduced by permission of © 1986 Van Nostrand Reinhold.)
Figure 8.13 Site diversity measurements in Virginia using the 11.6 GHz SIRIO beacon. (Source: Ippolito [1]; reproduced by permission of © 1986 Van Nostrand Reinhold.)
Figure 8.14 Three site Tampa Triad diversity measurements. (Source: Ippolito [1]; reproduced by permission of © 1986 Van Nostrand Reinhold.)
Figure 8.15 Baseline orientation in diversity systems. (Source: Ippolito [1]; reproduced by permission of © 1986 Van Nostrand Reinhold.)
Figure 8.16 Site diversity gain versus site separation and baseline orientation for sample system.
Figure 8.17 Relationship between percentages of time with two-site diversity,
p
2
, and without diversity,
p
1
, for the same path attenuation. (Source: ITU-R P.618-8 [10]; reproduced by permission of International Telecommunications Union.)
Figure 8.18 Burst time plan for TDMA site diversity experiment. (Source: Ippolito [1]; reproduced by permission of © 1986 Van Nostrand Reinhold.)
Figure 8.19 Diversity switching response for TDMA experiment. (Source: Ippolito [1]; reproduced by permission of © 1986 Van Nostrand Reinhold.)
Figure 8.20 Cumulative distribution of BER for looped back and diversity operation (Source: Ippolito [1]; reproduced by permission of © 1986 Van Nostrand Reinhold.)
Figure 8.21 Predicted orbit diversity performance for Spino d'Adda, Italy. (Source: Ippolito [15]; reproduced by permission of NASA.)
Figure 8.22 Orbit diversity measurements at Palmetto, GA. (Source: Ippolito [15]; reproduced by permission of NASA.)
Chapter 9: The Composite Link
Figure 9.1 Inclusion of RF path loss and path noise in evaluation of satellite communications performance.
Figure 9.2 Parameters for link performance calculations.
Figure 9.3 Frequency translation (FT) transponder.
Figure 9.4 Effects of path attenuation on system performance mode 1, uplink limited case.
Figure 9.7 Effects of path attenuation on system performance mode 4, equal high power case.
Figure 9.5 Effects of path attenuation on system performance mode 2, equal link case.
Figure 9.6 Effects of path attenuation on system performance mode 3, downlink limited case.
Figure 9.8 On-board processing (OBP) satellite transponder.
Figure 9.9 Comparison of OBP and FT transponder performance for BFSK.
Figure 9.10 Satellite link representation for intermodulation noise analysis.
Figure 9.11 Performance analysis process for a satellite communications link.
Chapter 10: Satellite Communications Signal Processing
Figure 10.1 Signal processing elements in satellite communications.
Figure 10.2 Analog voice baseband formats.
Figure 10.3 Analog video NTSC composite baseband signal spectrum. (Source: Pratt et al. [1]; reproduced by permission of © 2003 John Wiley & Sons, Inc.)
Figure 10.4 Signal processing format and spectrum for analog video satellite transmission.
Figure 10.5 Analog voice frequency division multiplexing.
Figure 10.6 Amplitude modulation.
Figure 10.7 Frequency modulation performance enhancement.
Figure 10.8 Binary waveforms used for encoding baseband data.
Figure 10.9 Multi-level encoding.
Figure 10.10 Pulse code modulation (PCM) coding/decoding process.
Figure 10.11 Time Division Multiplexing (TDM) source combining process for analog PCM encoded voice.
Figure 10.12 TDM BYTE multiplexing.
Figure 10.13 Signal format for DS1 and CEPT 1 levels.
Figure 10.14 Digital carrier modulation.
Figure 10.15 Basic digital modulation formats.
Figure 10.16 BPSK modulation implementation and frequency spectrum.
Figure 10.17 BPSK demodulator.
Figure 10.18 Gaussian noise channel bit error region.
Figure 10.19 Generation of the QPSK waveform.
Figure 10.20 QPSK modulator implementation.
Figure 10.21 QPSK modulator phase states.
Figure 10.22 QPSK demodulator.
Figure 10.23 phase state diagram.
Figure 10.24 Summary of signal processing elements in satellite communications.
Chapter 11: Satellite Multiple Access
Figure 11.1 Access options in a satellite communications network.
Figure 11.2 Frequency Division Multiple Access, FDMA.
Figure 11.3 Time Division Multiple Access, TDMA.
Figure 11.4 TDMA frame structure.
Figure 11.5 SS/TDMA network configuration.
Figure 11.6 Switch matrix settings for SS/TDMA network.
Figure 11.7 Code Division Multiple Access, CDMA.
Figure 11.8 n-Stage feedback shift register PN sequence generator.
Figure 11.9 Generation of PN data stream.
Figure 11.10 DS-SS satellite system elements.
Figure 11.11 Functional representation of DS-SS BPSK waveform generation.
Figure 11.12 DS-SS BPSK modulator implementation.
Figure 11.13 DS-SS BPSK demodulator implementation.
Figure 11.14 FH-SS satellite system elements.
Chapter 12: The Mobile Satellite Channel
Figure 12.1 Reflection.
Figure 12.2 Diffraction.
Figure 12.3 Narrowband and wideband fading on mobile channels.
Figure 12.4 Received signal power for a moving mobile receiver in a narrowband fading mobile channel.
Figure 12.5 Components of narrowband fading channel. (Source: Saunders [2]; reproduced by permission of © 2004 John Wiley & Sons, Ltd.)
Figure 12.6 Measured signal level variations for a satellite link with a moving mobile in a suburban environment. (Source: Saunders [2]; reproduced by permission of © 2004 John Wiley & Sons, Ltd.)
Figure 12.7 Two slope model for g(r).
Figure 12.8 Two-ray path propagation link model.
Figure 12.9 Shadow fading component.
Figure 12.10 Roadside tree-shadow fading exceedance versus path elevation angle for a 1.5 GHz mobile satellite link, from the ITU-R roadside tree-shadowing model. (Source: ITU-R Rec. P.681-9 [12]; reproduced by permission of International Telecommunications Union.)
Figure 12.11 Geometry for ITU-R roadside building shadowing model. (Source: ITU-R Rec. P.681-9 [12]; reproduced by permission of International Telecommunications Union.)
Figure 12.12 Sample calculation for roadside building shadowing.
Figure 12.13 Rayleigh distribution for the multipath fading factor .
Figure 12.14 Probability distribution for the total Received rower .
Figure 12.15 Probability distribution of the amplitude of the received signal with a direct ray.
Figure 12.16 Cumulative distributions of fade depth for multipath fading in mountainous terrain. (Source: ITU-R Rec. P.681-9 [12]; reproduced by permission of International Telecommunications Union.)
Figure 12.17 Cumulative distributions of fade depth for multipath fading on tree lined roads. (Source: ITU-R Rec. P.681-9 [12]; reproduced by permission of International Telecommunications Union.)
Figure 12.18 Building configurations for the street masking function (MKF) model. (Source: ITU-R Rec. P.681-9 [12]; reproduced by permission of International Telecommunications Union.)
Figure 12.19 MKFs for the four configurations of Figure 12.18. (Source: ITU-R Rec. P.681-9 [12]; reproduced by permission of International Telecommunications Union.)
Figure 12.20 Determination of link availability for a GSO satellite – T-junction MKF scenario. (Source: ITU-R Rec. P.681-9 [12]; reproduced by permission of International Telecommunications Union.)
Figure 12.21 Three propagation states for modeling mixed propagation conditions on mobile satellite links. (Source: ITU-R Rec. P.681-9 [12]; reproduced by permission of International Telecommunications Union.)
Figure 12.22 Cumulative distribution function of signal level in urban and suburban areas for mixed propagation conditions on a mobile satellite link. (Source: ITU-R Rec. P.681-9 [12]; reproduced by permission of International Telecommunications Union.)
Figure 12.23 Wideband channel Intersymbol Interference (ISI). (Source: Saunders [2]; reproduced by permission of © 2004 John Wiley & Sons, Ltd.)
Figure 12.24 Impact of wideband delay on BER. (Source: Saunders [2]; reproduced by permission of © 2004 John Wiley & Sons, Ltd.)
Figure 12.25 Parameters for street canyon shadowing cross-correlation coefficient. (Source: ITU-R Rec. P.681-9 [12]; reproduced by permission of International Telecommunications Union.)
Figure 12.26 Multi-satellite shadowing cross correlation coefficient for a street canyon. (Source: ITU-R Rec. P.681-9 [12]; reproduced by permission of International Telecommunications Union.)
Chapter 13: Spectrum Management in Satellite Communications
Figure 13.1 Organization of the International Telecommunications Union (ITU).
Figure 13.2 Dates and locations of recent World Radio Conferences (WRCs) convened by the ITU-R.
Figure 13.3 International Telecommunications Union (ITU) service designations for common communications services.
Figure 13.4 International Telecommunications Union (ITU) service regions. (Source: ITU-R Radio Regulations, Edition of 2012, [13.1]. Reproduced with permission of International Telecommunication Union.)
Figure 13.5 Sample page from ITU-R radio regulations frequency allocation table 24.75 to 29.9 GHz. (Source: ITU-R Radio Regulations, Edition of 2012, [13.1]. Reproduced with permission of International Telecommunication Union.)
Figure 13.6 Federal Communications Commission (FCC) organization. (Source: Federal Communications Commission (FCC), [13.3].)
Figure 13.7 Frequency allocation process in the United States.
Figure 13.8 Sample page from the NTIA Manual of Regulations and Procedures for federal radio frequency management 10.0 to 12.2 GHz [4]. (Source: NTIA Manual of Regulations and Procedures, [13.4].)
Figure 13.9 FCC band segmentation plan for the 27.5-30 GHz band. (Source: FCC NPRM Docket No. 95–287, [13.6].)
Chapter 14: Interference Mitigation in Satellite Communications
Figure 14.1 Possible modes of interference for space networks.
Figure 14.2 Clear air long-term interference propagation mechanisms. (Source: ITU-R Recommendation P.452-16, Figure 1, modified, [1]. Reproduced with permission of International Telecommunication Union.)
Figure 14.3 Short-term interference propagation mechanisms. (Source: ITU-R Recommendation P.452-16, Figure 1, modified, [1]. Reproduced with permission of International Telecommunication Union.)
Figure 14.4 Power flux density for a single RF link.
Figure 14.5 Coordination contour for hydrometeor (rain) scatter propagation.
Chapter 15: High Throughput Satellites
Figure 15.1 CONUS spot beams for Spaceway 3. (Source: [3]. Reproduced with permission of SatStar.)
Figure 15.2 Projected growth in satellite broadband subscribers. (Source: ITU-R News [4]. Reproduced by permission of Northern Sky Research, LLC.)
Figure 15.3 Multi-beam antenna array clusters.
Figure 15.4 Multi-beam array configurations for N = 4 and N = 7.
Figure 15.6 Dimensions of a single hexagonal beam.
Figure 15.5 Determination of nearest co-channel beams.
Figure 15.7 Ground terminal location with interfering adjacent beams.
Figure 15.8 Path and angle geometry for SIR determination.
Figure 15.9 STAR satellite network.
Figure 15.10 STAR network gateway implementation.
Figure 15.11 MESH satellite network.
Figure 15.12 Satellite antenna beam coverage areas from GSO.
Figure 15.13 Detailed timeline and process for ITU-R IMT-2020. (Source: ITU towards OMT for 2020 and beyond, [5]. Reproduced with permission of International Telecommunication Union.)
Figure 15.14 Total global mobile traffic estimates from 2020 to 2030. (Source: ITU-R Report M.2370, Figure 7 and 8, [9]. Reproduced with permission of International Telecommunication Union.)
Figure 15.15 Satellite as an integral part of the 5G ecosystem. (Source: [11]. Reproduced with permission of EMEA Satellite Operators Association (ESOA).)
Appendix: Error Functions and Bit Error Rate
Figure A.1 The normal probability function.
Figure A.2 Estimation for the BER.
List of Tables
Chapter 2: Satellite Orbits
Table 2.1 Orbit altitudes for specified orbital periods
Table 2.2 Determination of azimuth angle from intermediate angle
Chapter 4: The RF Link
Table 4.1 Wavelength and frequency
Table 4.2 Antenna gain, diameter, frequency dependence
Table 4.3 Antenna beamwidth for the circular parabolic reflector antenna
Table 4.4 Representative free space path losses for satellite links
Table 4.5 Transition frequency, thermal versus quantum noise
Table 4.6 Noise figure and effective noise temperature
Chapter 5: Link System Performance
Table 5.1 Annual and monthly outage time for specified percent outage availability
Chapter 6: Transmission Impairments
Table 6.1 Observed characteristics of typical cloud types
Table 6.2 Sky temperature from clouds at zenith (90
°
elevation angle)
Chapter 7: Propagation Effects Modeling and Prediction
Table 7.2 Spectroscopic data for water vapor attenuation
Table 7.1 Spectroscopic data for oxygen attenuation
Table 7.3 Characteristics of Slobin model cloud types
Table 7.4 Cloud attenuation at zenith (90
o
elevation angle) from the Slobin model
Table 7.5 Regression coefficients for determination of specific attenuation
Table 7.6 Rain rate distributions for global model rain climate regions
Table 7.7 Global model rain heights for 0.001% and 1.0%
Table 7.8 Two-component model rain distribution parameters
Chapter 9: The Composite Link
Table 9.1 Link parameters for the Communications Technology Satellite (CTS)
Table 9.2 Carrier-to-noise ratios for the CTS (Clear sky conditions: A
U
= A
D
= 0 dB)
Chapter 10: Satellite Communications Signal Processing
Table 10.1 Standardized TDM structures
Chapter 11: Satellite Multiple Access
Table 11.1 INTELSAT TDMA preamble and reference burst structure
Table 11.2 3 × 3 matrix switch modes
Chapter 12: The Mobile Satellite Channel
Table 12.1 Fade levels (in dB) exceeded at θ = 80
°
elevation angle
Table 12.2 Best fit parameters for mountain environment multipath model
Chapter 13: Spectrum Management in Satellite Communications
Table 13.1 Methods to facilitate spectrum sharing
Chapter 14: Interference Mitigation in Satellite Communications
Table 14.1 ITI-R interference coordination documents matrix
Chapter 15: High Throughput Satellites
Table 15.1 Multi-beam antenna tessellate integer values for N
Satellite Communications Systems Engineering
Atmospheric Effects, Satellite Link Design and System Performance
Louis J. Ippolito, Jr.
Engineering Consultant and Adjunct Professor,The George Washington University,Washington DC, USA
Second Edition
This edition first published 2017
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List of Acronyms
5G
Fifth generation mobile systems
8φPSK
8-phase phase shift keying
A
ACI
adjacent channel interference
ACM
adaptive coded modulation
ACTS
Advanced Communications Technology Satellite
A/D
analog to digital converter
ADM
adaptive delta modulation
ADPCM
adaptive differential pulse code modulation
AGARD
Advisory Group for Aeronautical Research and Development (NATO)
AIAA
American Institute of Aeronautics and Astronautics
AM
amplitude modulation
AMI
alternate mark inversion
AMSS
aeronautical mobile satellite service
AMSS
aeronautical mobile satellite service
AOCS
Attitude and Orbit Control System
ATS-
Applications Technology Satellite-
AWGN
additive white Gaussian noise
Az
azimuth (angle)
B
BB
baseband
BER
bit error rate
BFSK
binary frequency shift keying
BO
backoff
BOL
beginning of life
BPF
band pass filter
BPSK
binary phase shift keying
BSS
broadcast satellite service
C
CBR
carrier and bit-timing recovery
CCI
co-channel interference
CDC
coordination and delay channel
CDF
cumulative distribution function
CDMA
code division multiple access
CEPT
European Conference of Postal and Telecommunications Administrations
C/I
carrier to interference ratio
CLW
cloud liquid water
cm
centimeters
C/N
carrier-to-noise ratio
C/No
carrier-to-noise density
COMSAT
Communications Satellite Corporation
CONUS
continental United States
CPA
copolar attenuation
CPM
Conference Preparatory Meeting
CRC
cyclic redundancy check
CSC
common signaling channel
CTS
Communications Technology Satellite
CVSD
continuously variable slope delta modulation
D
D.C.
down converter
DA
demand assignment
DAH
Dissanayake, Allnutt, and Haidara (rain attenuation model)
DAMA
demand assigned multiple access
dB
decibel
dBHz
decibel-Hz
dbi
decibels above isotropic
dBK
decibel-Kelvin
dBm
decibel-milliwatts
dBW
decibel-watt
DEM
demodulator
DOS
United States Department of State
DS
digital signaling (also known as T-carrier TEM signaling)
DSB/SC
double sideband suppressed carrier
DSI
digital speech interpolation
DS-SS
direct sequence spread spectrum
E
Eb/No
energy per bit to noise density
EHF
extremely high frequency
EIRP
effective isotropic radiated power
El
elevation angle
EOL
end of life
epfd
equivalent power flux density
erf
error function
erfc
complimentary error function
ERS
empirical roadside shadowing
ES
earth station
ESA
European Space Agency
E-W
east-west station keeping
F
FA
fixed access
FCC
Federal Communications Commission
FDM
frequency division multiplex
FDMA
frequency division multiple access
FEC
forward error correction
FET
field effect transistor
FH-SS
frequency hopping spread spectrum
FM
frequency modulation
FSK
frequency shift keying
FSS
fixed satellite service
FT
frequency translation transponder
G
GEO
geostationary satellite orbit
GHz
gigahertz
GSM
Global System for Mobile
GSO
geosynchronous satellite orbit
G/T,
receiver figure of merit
H
HAPS
high altitude stratospheric platform stations
HEO
high elliptical earth orbit, high earth orbit
HEW
Health Education Experiment
HF
high frequency
HP
horizontal polarization
hPa
hectopascal (unit for air pressure, equal to 1 cm H
2
O)
HPA
high power amplifier
HSPA
High-Speed Packet Access
HTS
High Throughput Satelite
Hz
hertz
I
IEE
Institute of Electrical Engineers
IEEE
Institute of Electrical and Electronics Engineers
IF
intermediate frequency
IMT-2000
ITU International Mobile Telecommunications Program - 2000
IMT-2020
ITU International Mobile Telecommunications Program - 2020
INTELSAT
International Satellite Organization
IoT
Internet of Things
IRAC
Interdepartmental Radio Advisory Committee
ISI
intersymbol interference
ITU
International Telecommunications Union
ITU-D
International Telecommunications Union, Development Sector
ITU-R
International Telecommunications Union, Radiocommunications Sector
ITU-T
International Telecommunications Union, Telecommunications Standards Sector
JK
K
degrees Kelvin
Kbps
kilobits per second
kg
kilogram
KHz
kilohertz
km
kilometers
L
LEO
low earth orbit
LF
low-frequency
LHCP
left hand circular polarization
LMSS
land mobile satellite service
LMSS
land mobile satellite service
LNA
low noise amplifier
LNB
low noise block
LO
local oscillator
LOS
line-of-site
LPF
low pass filter
LTE
Long Term Evolution
M
M2M
machine-to-machine
m
meters
MA
multiple access
MAC
medium access control
Mbps
megabits per second
MCPC
multiple channel per carrier
MEO
medium earth orbit
MF
medium frequency
MF-TDMA
multi-frequency time division multiple access
MHz
megahertz
MI
Mutual Interference
MKF
street masking function
MMSS
maritime mobile satellite service
MOD
modulator
MODEM
modulator/demodulator
MSK
minimum shift keying
MSS
mobile satellite, service
MUX
multiplexer
N
NASA
National Aeronautics and Space Administration
NF
noise figure (or noise factor)
NGSO
non geosynchronous (or geostationary) satellite orbit
NIC
nearly instantaneous companding
NRZ
non return to zero
N-S
north-south station keeping
NTIA
National Telecommunications and Information Agency
NTSC
National Television System Committee
O
OBP
on-board processing transponder
OFDM
orthogonal frequency division multiplexing
OFDMA
orthogonal frequency division multiple access
OOK
on/off keying
P
PA
pre-assigned access
PACS
Personal Access Communications System
PAL
phase alternation line
PAM
pulse amplitude modulation
PCM
pulse code modulation
PFD
power flux density
PLACE
Position Location and Aircraft Communication Experiment
PN
pseudorandom sequence
PSK
phase shift keying
PSTN
public switched telephone network
Q
QAM
quadrature amplitude modulation
QPSK
quadrature phase shift keying
R
REC
receiver
RF
radio frequency
RFI
radio frequency interference
RHCP
right hand circular polarization
RZ
return to zero
S
SC
service channel
SCADA
Supervisory Control and Data Acquisition
SCORE
Signal Communications Orbiting Relay Experiment
SCPC
single channel per carrier
SDMA
space division multiple access
SECAM
SEquential Couleur Avec Memoire
SGN
satellite news gathering
SHF
super high frequency
SIR
signal-to-interference ratio
SITE
satellite instructional television experiment
S/N
signal-to-noise ratio
SS
subsatellite point
SS/TDMA
time division multiple access, satellite switched
SSB/SC
single sideband suppressed carrier
SSPA
solid state amplifier
SUE
Spectrum Utilization Efficiency
SYNC
synchronization
T
TDM
time division multiplex(ing)
TDMA
time division multiple access
TDRS
Tracking and Data Relay Satellite
TEC
total electron content
TIA
Telecommunications Industry Association
T-R
transmitter-receiver
TRANS
transmitter
TRUST
Television Relay Using Small Terminals
TT&C
tracking, telemetry and command
TTC&M
tracking, telemetry, command and monitoring
TTY
teletype
TWT
traveling wave tube
TWTA
traveling wave tube amplifier
U
UHF
ultra-high frequency
UMTS
Universal Mobile Telecommunications System
USSR
Union of Soviet Socialist Republics
UW
unique word
V
VA
voice activation (factor)
VF
voice frequency (channel)
VHF
very high frequency
VLF
very low frequency
VOW
voice order wire
VP
vertical polarization
VPI&SU
Virginia Polytechnic Institute and State University
VSAT
very small antenna (aperture) terminal
W
WARC
World Administrative Radio Conference
WCDMA
Wideband CDMA
WRC
World Radio Conference
WVD
water vapor density
X
XPD
cross-polarization discrimination
Y
Z
Preface to Second Edition
This second edition of Satellite Communications Systems Engineering – Atmospheric Effects, Satellite Link Design, and System Performance is written for those concerned with the design and performance of satellite communications systems employed in fixed point to point, broadcasting, mobile, radio navigation, data relay, computer communications, and related satellite-based applications. The rapid growth in satellite communications has created a continued need for accurate information on both satellite communications systems engineering and the impact of atmospheric effects on satellite link design and system performance. This second edition addresses that need for the first time in a single comprehensive source. One of the major advancements since the publication of the first book has been the move to higher frequencies of operation and higher capacity satellite networks, and this second edition includes all of the important elements of this evolution.
New topic areas covered in this second edition include broadband and high throughput satellites (HTS), interference mitigation in satellite communications, electronic propulsion satellites, frequency management for satellite communications, added emphasis on the new higher frequency bands – Ka-band, Q/V/W-bands, and the role of satellite networks in the 5G environment.
The book highlights the significant progress that has been made in the understanding and modeling of propagation effects on radiowave propagation in the bands utilized for satellite communications. This second edition continues and updates, in a single source, the comprehensive description and analysis of all of the atmospheric effects of concern for today's satellite systems and the tools necessary to design the links and evaluate system performance. Many of the tools and calculations are provided in a “handbook” form, with step-by-step procedures and all necessary algorithms in one place to allow direct calculations without the need to consult other material. All of the procedures and prediction models, particularly those provided by the International Telecommunications Union Radio Communications Sector (ITU-R), have been fully upgraded to their latest published versions, and several new models and predictions have been added.
The book provides the latest information on communications satellite link design and performance from the practicing engineer perspective – concise descriptions, specific procedures, and comprehensive solutions. We focus on the satellite free-space link as the primary element in the design and performance for satellite communications. This focus recognizes and includes the importance of free-space considerations such as atmospheric effects, frequency of operation and adaptive mitigation techniques.
The reader can enter the book from at least three perspectives;
for basic information on satellite systems and related technologies, with minimum theoretical developments and practical, useable, up-to-date information,
as a satellite link design handbook, with extensive examples, step-by-step procedures, and the latest applications oriented solutions, and
as a textbook for a graduate level course on satellite communications systems – the book includes problems at the end of many chapters.
Unlike many other books on satellite communications, this book does not bog down the reader in specialized, regional technologies and hardware dependent developments that have limited general interest and a short lifetime. The intent of this author is to keep the book relevant for the entire global wireless community by focusing on the important basic principles that are unique and timeless to satellite-based communications delivery systems.
I would like to acknowledge the contributions of the many individuals and organizations whose work and efforts are reflected and referenced in this book. I have had the privilege of knowing and working with many of these researchers, some pioneers in the field of satellite communications, through my long affiliations with NASA, the ITU-R, and other organizations. The ideas and concepts that led to the development of this book were honed and enhanced through extensive discussions and interchange of ideas with many of the original developers of the technologies and processes covered in the book.
Finally, I gratefully acknowledge the support and encouragement of my wife, Sandi, who kept me focused on the second edition project and whose patience I could always count on. This book is dedicated to Sandi, and to our children, Karen, Rusty, Ted, and Cathie.
June 2016Louis J. Ippolito, Jr.
Chapter 1Introduction to Satellite Communications
A communications satellite is an orbiting artificial earth satellite that receives a communications signal from a transmitting ground station, amplifies and possibly processes it, then transmits it back to the earth for reception by one or more receiving ground stations. Communications information neither originates nor terminates at the satellite itself. The satellite is an active transmission relay, similar in function to relay towers used in terrestrial microwave communications.
The commercial satellite communications industry had its beginnings in the mid 1960s, and in less than 50 years has progressed from an alternative exotic technology to a mainstream transmission technology, which is pervasive in all elements of the global telecommunications infrastructure. Today's communications satellites offer extensive capabilities in applications involving data, voice, and video, with services provided to fixed, broadcast, mobile, personal communications, and private networks users.
Satellite communications are now an accepted fact of everyday life, as evidenced by the antennas or “dishes,” which dot city and country horizons, or the nearly instantaneous global news coverage that is taken for granted, particularly in times of international crises.
The communications satellite is a critical element in the overall telecommunications infrastructure, as represented by Figure 1.1, which highlights, by the shaded area, the communications satellite component as related to the transmission of information. Electronic information in the form of voice, data, video, imaging, and so on, is generated in a user environment on or near the earth's surface. The information's first node is often a terrestrial interface, which then directs the information to a satellite uplink, which generates a RF (radio frequency) radiowave, which propagates thought the air link to an orbiting satellite (or satellites). The information-bearing radiowave is amplified and possibly processed at the satellite, then reformatted and transmitted back to a receiving ground station through a second RF radiowave propagating through the air link. Mobile users, indicated by the vehicle and handheld phone on the figure, generally bypass the terrestrial interface only for direct mobile to mobile communications.
Figure 1.1 Communications via satellite in the telecommunications infrastructure.
Communications by satellite offers a number of features that are not readily available with alternative modes of transmission, such as terrestrial microwave, cable or fiber networks. Some of the advantages of satellite communications are:
Distance Independent Costs
The cost of satellite transmission is basically the same, regardless of the distance between the transmitting and receiving earth stations. Satellite-based transmission costs tend to be more stable, particularly for international or intercontinental communications over vast distances.
Fixed Broadcast Costs
The cost of satellite broadcast transmission, that is, transmission from one transmit ground terminal to a number of receiving ground terminals, is independent of the
number
of ground terminals receiving the transmission.
High Capacity
Satellite communications links involve high carrier frequencies, with large information bandwidths. Capacities of typical communications satellites range from 10s to 100s of Mbps (megabits per second), and can provide services for several hundred video channels or several tens of thousands of voice or data links.
Low Error Rates
Bit errors on a digital satellite link tend to be
random
, allowing for statistical detection and error correction techniques to be utilized. Error rates of one bit error in 10
6
bits or higher can be routinely achieved efficiently and reliably with standard equipment.
Diverse User Networks
Large areas of the earth are visible from the typical communications satellite, allowing the satellite to link together many users simultaneously. Satellites are particularly useful for accessing remote areas or communities not otherwise accessible by terrestrial means. Satellite terminals can be on the surface, at sea, or in the air, and can be fixed or mobile.
The successful implementation of satellite wireless communications requires robust air links providing the uplink and downlink paths for the communications signal. Transmission through the atmosphere will degrade signal characteristics, however, and under some conditions can be the major impediment to successful system performance. A detailed knowledge of the types of atmospheric effects that impact satellite communications and the means to predict and model them for application to communications link design and performance is essential for wireless satellite link engineering. The effects of the atmosphere are even more significant as current and planned satellites move up to higher operating frequencies, including the Ku-band (14 GHz uplink/12 GHz downlink), Ka-band (30 GHz/20 GHz), and V-band (50 GHz/40 GHz), where the effects of rain, gaseous attenuation, and other effects will increase.
1.1 Early History of Satellite Communications
The idea of a synchronous orbiting satellite capable of relaying communications to and from the earth is generally attributed to Arthur C. Clarke. Clark observed in his classic 1945 paper [1] that a satellite in a circular equatorial orbit with a radius of about 23,000 miles (42,000 km) would have an angular velocity matching that of the earth, thus it would remain above the same spot on the earth's surface. This orbiting artificial satellite could therefore receive and transmit signals from anywhere on earth in view of the satellite to any other place on the surface in view of the satellite.
The technology to verify this concept was not available until over a decade later, with the launch in 1957 of SPUTNIK I by the former USSR. This launch ushered in the 'space age' and both the United States and the USSR began robust space programs to develop the technology and to apply it to emerging applications. A brief summary of some of the early communications satellites programs, and their major accomplishments, follows.
1.1.1 SCORE
The first communications by artificial satellite was accomplished by SCORE (Signal Communicating by Orbiting Relay Equipment), launched by the Air Force into a low (100 by 800 nautical mile) orbit in December 1958. SCORE relayed a recorded voice message, on a delayed basis, from one earth station to another. SCORE broadcast a message from President Eisenhower to stations around the world, giving the first hint of the impact that satellites would have on point to point communications. The maximum message length was 4 minutes, and the relay operated on a 150 MHz uplink and 108 MHz downlink. SCORE, powered by battery only, operated for 12 days before its battery failed, and decayed out of orbit 22 days later [2].
1.1.2 ECHO
The first of several efforts to evaluate communications relay by passive techniques was initiated with the ECHO satellites 1 and 2, launched by the National Aeronautics and Space Administration, NASA, in August 1960 and January 1964, respectively. The ECHO satellites were large orbiting spheres of aluminized Mylar, over 100 ft in diameter, which served as passive reflectors for signals transmitted from stations on the earth. They caught the interest of the public since they were visible from the earth with the unaided eye under the right lighting conditions, usually just as the sun was rising or setting. The ECHO relays operated at frequencies from 162 MHz to 2390 MHz, and required large ground terminal antennas, typically 60 ft. or more, with transmit powers of 10 kW. ECHO 1 remained in orbit for nearly eight years, ECHO 2 for over five years [3].
1.1.3 COURIER
Launched in October 1960, COURIER extended SCORE delayed repeater technology and investigated store-and-forward and real-time capabilities from a low orbiting satellite. COURIER operated with an uplink frequency of 1.8 to 1.9 GHz, and a downlink of 1.7 to 1.8 GHz. It was all solid state except for the two-watt output power tubes, and was the first artificial satellite to employ solar cells for power. The satellite performed successfully for 17 days, until a command system failure ended operations [4].
1.1.4 WESTFORD
WESTFORD was the second technology employed to evaluate communications relay by passive techniques, with a first successful launch by the U.S. Army in May 1963. WESTFORD consisted of tiny resonant copper dipoles dispersed in an orbital belt, with communications accomplished by reflection from the dispersed dipole reflectors. The dipoles were sized to the half wavelength of the relay frequency, 8350 MHz. Voice and frequency shift keyed (FSK) transmissions up to 20 kbps were successfully transmitted from a ground station in California to one in Massachusetts. As the belt dispersed, however, the link capacity dropped to below 100 bps. The rapid development of active satellites reduced interest in passive communications, and ECHO and WESTFORD brought passive technology experiments to an end [5].
1.1.5 TELSTAR
The TELSTAR Satellites 1 and 2, launched into low orbits by NASA for AT&T/Bell Telephone Laboratories in July 1962 and May 1963, respectively, were the first active wideband communications satellites. TELSTAR relayed analog FM signals, with a 50 MHz bandwidth, and operated at frequencies of 6.4 GHz on the uplink and 4.2 GHz on the downlink. These frequencies led the way for 6/4 GHz C-band operation, which currently provides the major portion of fixed satellite service (FSS) throughout the world. TELSTAR 1 provided multichannel telephone, telegraph, facsimile, and television transmissions to stations in the United States, Britain, and France until the command subsystem failed in November 1962 due to Van Allen belt radiation. TELSTAR 2, redesigned with radiation resistant transistors and launched into a higher orbit to decrease exposure in the Van Allen belts, operated successfully for two years [6].
1.1.6 RELAY
RELAY 1, developed by RCA for NASA, was launched in December 1962 and operated for fourteen months. RELAY had two redundant repeaters, each with a 25 MHz channel and two 2 MHz channels. It operated with 1725 MHz uplink and 4160 MHz downlink frequencies, and had a 10-watt TWT (traveling wave tube) output amplifier. Extensive telephony and network television transmissions were accomplished between the United States, Europe, and Japan. RELAY 2 was launched in January 1964 and operated for 14 months. The RELAY and TELSTAR programs demonstrated that reliable, routine communications could be accomplished from orbiting satellites, and further indicated that satellite systems could share frequencies with terrestrial systems without interference degradations [7].
1.1.7 SYNCOM
The SYNCOM satellites, developed by Hughes Aircraft Company for NASA GSFC, provided the first communications from a synchronous satellite. SYNCOM 2 and 3 were placed on orbit in July 1963 and July 1964, respectively (SYNCOM 1 failed at launch). SYNCOM, with 7.4 GHz uplink and 1.8 GHz downlink frequencies, employed two 500 kHz channels for two-way narrowband communications, and one 5 MHz channel for one-way wideband transmission. SYNCOM was the first testbed for the development of station keeping and orbital control principles for synchronous satellites. It was the first satellite to employ range and range-rate tracking. NASA conducted voice, teletype and facsimile tests, including extensive public demonstrations to increase the base of satellite communications interest. The U.S. Department of Defense also conducted tests using SYNCOM 2 and 3, including transmissions with a shipboard terminal. Tests with aircraft terminals were also conducted with the SYNCOM VHF command and telemetry links [8].
1.1.8 EARLYBIRD
The first commercial operational synchronous communications satellite was EARLYBIRD, later called INTELSAT I, developed by COMSAT for INTELSAT, and launched by NASA in April 1965. The communications subsystem, very similar to the SYNCOM 3 design, had two 25 MHz transponders and operated at C-band, with uplinks at 6.3 GHz and downlinks at 4.1 GHz. It had a capacity of 240 two-way voice circuits or one two-way television circuit. TWT output power was 6 watts. Operations between the U.S. and Europe began on June 28, 1965, a date that many recognize as the birth date of commercial satellite communications. EARLYBIRD remained in service until August 1969, when it was replaced by later generation INTELSAT III satellites [9].
1.1.9 APPLICATIONS TECHNOLOGY SATELLITE-1, ATS-1
The ATS-1, first of NASA's highly successful series of Applications Technology Satellites, was launched in December 1966 and demonstrated a long list of “firsts” in satellite communications. ATS-1 included an electronically despun antenna with 18-dB gain and a 17o beamwidth. It operated at C-band (6.3 GHz uplink, 4.1 GHz downlink), with two 25 MHz repeaters. ATS-1 provided the first multiple access communications from synchronous orbit. ATS-1 had VHF links (149 MHz uplink, 136 MHz downlink) for the evaluation of air to ground communications via satellite. ATS-1 also contained a high-resolution camera, providing the first photos of the full earth from orbit. ATS-1 continued successful operation well beyond its three year design life, providing VHF communications to the Pacific basin region until 1985, when station keeping control was lost [7].
1.1.10 ATS-3
The ATS-3, launched in November 1967, continued experimental operations in the C and VHF bands, with multiple access communications and orbit control techniques. ATS-3 allowed, for the first time, “cross-strap” operation at C-band and VHF; the signal received at VHF could be transmitted to the ground at C-band. ATS-3 provided the first color high-resolution pictures of the now familiar “blue marble” earth as seen from synchronous orbit. ATS-3, like ATS-1, far exceeded its design life, and providing VHF communications to the Pacific and continental United States for public service applications for over a decade [7].
1.1.11 ATS-5
ATS-5 had a C-band communications subsystem similar to its predecessors, but did not have the VHF capability. Instead it had an L-band (1650 MHz uplink, 1550 MHz downlink) subsystem to investigate air to ground communications for navigation and air traffic control. ATS-5 also contained a millimeter wave experiment package that operated at 31.65 GHz (uplink) and 15.3 GHz (downlink), designed to provide propagation data on the effects of the atmosphere on earth-space communications at these frequencies. ATS-5 was designed to operate as a gravity gradient stabilized satellite, unlike the earlier spin-stabilized ATS-1 and -3 satellites. It was successfully launched in August 1969 into synchronous orbit, but the gravity stabilization boom could not be deployed because of the satellite's spin condition. ATS-5 was placed into a spin-stabilized condition, resulting in the satellite antennas sweeping the earth once every 860 milliseconds. Most of the communications experiments performed with limited success in this unexpected “pulsed” operation mode. The 15.3 GHz millimeter wave experiment downlink, however, was able to function well, after modifications to the ground terminal receivers, and extensive propagation data were accumulated at over a dozen locations in the United States and Canada [7].
1.1.12 ANIK A
ANIK A (initially called ANIK I), launched in November 1972 by NASA for Telsat Canada, was the first domestic commercial communications satellite. Two later ANIK As were launched in April 1973 and May 1975. The satellites, built by Hughes Aircraft Company, operated at C-band and had 12 transponders, each 36 MHz wide. The primary services provided were television distribution, SCPC (single channel per carrier) voice, and data services. The transmit power was 5 watts, with a single beam covering most of Canada and the northern United States. The antenna pattern for ANIK A was optimized for Canada, however, sufficient coverage of the northern United States was available to allow leased service by U.S. communications operators for domestic operations prior to the availability of U.S. satellites. The ANIK A series continued in service until 1985, when they were replaced by ANIK D satellites [10].
