- 1. SATELLITE COMMUNICATIONSSYSTEMSFifth Edition
2. SATELLITE COMMUNICATIONSSYSTEMS Systems, Techniques and
Technology Fifth EditionGrard Maral e Ecole Nationale Suprieure des
Tlcommunications,eeeSite de Toulouse, FranceMichel Bousquet Ecole
Nationale Suprieure de lAronautique et de lEspace (SUPAERO),e e
Toulouse, France Revisions to fth edition by Zhili SunUniversity of
Surrey, UK with contributions from Isabelle Buret,Thales Alenia
Space 3. Copyright 1986, 1993, 1998, 2002This edition rst published
2009 2009 John Wiley & Sons Ltd.Registered ofceJohn Wiley &
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Cataloging-in-Publication DataMaral, Grard.e [Systmes de
tlcommunications par satellites. English] e ee Satellite
communications systems / Grard Maral, Michel Bousquet. 5th ed.ep.
cm.Includes bibliographical references and index.ISBN
978-0-470-71458-4 (cloth) 1. Articial satellites in
telecommunication. I. Bousquet, Michel. II. Title.TK5104.M3513
2009621.3825dc222009023579A catalogue record for this book is
available from the British Library.ISBN 978-0-470-71458-4
(H/B)Typeset in 9/11 pt Palatino by Thomson Digital, Noida,
India.Printed in Singapore by Markono Print Media Pte Ltd.This book
is printed on acid-free paper responsibly manufactured from
sustainable forestry,in which at least two trees are planted for
each one used for paper production.Original translation into
English by J.C.C. Nelson. 4.
CONTENTSACKNOWLEDGEMENTxvACRONYMSxviiNOTATIONxxv1 INTRODUCTION1 1.1
Birth of satellite communications1 1.2 Development of satellite
communications1 1.3 Conguration of a satellite communications
system3 1.3.1 Communications links 4 1.3.2 The space segment5 1.3.3
The ground segment 8 1.4 Types of orbit 9 1.5 Radio regulations 12
1.5.1 The ITU organisation12 1.5.2 Space radiocommunications
services13 1.5.3 Frequency allocation131.6 Technology trends141.7
Services 151.8 The way forward17References 182 ORBITS AND RELATED
ISSUES19 2.1 Keplerian orbits19 2.1.1 Keplers laws 19 2.1.2 Newtons
law19 2.1.3 Relative movement of two point bodies 20 2.1.4 Orbital
parameters23 2.1.5 The earths orbit 28 2.1.6 Earthsatellite
geometry35 2.1.7 Eclipses of the sun 41 2.1.8 Sunsatellite
conjunction 42 2.2 Useful orbits for satellite communication 43
2.2.1 Elliptical orbits with non-zero inclination 43 2.2.2
Geosynchronous elliptic orbits with zero inclination54 2.2.3
Geosynchronous circular orbits with non-zero inclination56 2.2.4
Sub-synchronous circular orbits with zero inclination 59 2.2.5
Geostationary satellite orbits59 5. viContents2.3 Perturbations of
orbits68 2.3.1 The nature of the perturbations 69 2.3.2 The effect
of perturbations; orbit perturbation 71 2.3.3 Perturbations of the
orbit of geostationary satellites73 2.3.4 Orbit corrections:
station keeping of geostationary satellites81 2.4 Conclusion97
References973 BASEBAND SIGNALS AND QUALITY OF SERVICE 993.1
Baseband signals 99 3.1.1 Digital telephone signal 100 3.1.2 Sound
signals103 3.1.3 Television signals 104 3.1.4 Data and multimedia
signals1073.2 Performance objectives108 3.2.1 Telephone108 3.2.2
Sound108 3.2.3 Television 108 3.2.4 Data 1083.3 Availability
objectives 1093.4 Delay 111 3.4.1 Delay in terrestrial network 111
3.4.2 Propagation delay over satellite links 111 3.4.3
Baseband-signal processing time112 3.4.4 Protocol-induced delay 112
3.5 Conclusion 112 References 1134 DIGITAL COMMUNICATIONS
TECHNIQUES 1154.1 Baseband formatting 115 4.1.1 Encryption 115
4.1.2 Scrambling 1174.2 Digital modulation118 4.2.1 Two-state
modulationBPSK and DE-BPSK119 4.2.2 Four-state modulationQPSK 120
4.2.3 Variants of QPSK 121 4.2.4 Higher-order PSK and APSK124 4.2.5
Spectrum of unltered modulated carriers 125 4.2.6 Demodulation 125
4.2.7 Modulation spectral efciency1304.3 Channel coding131 4.3.1
Block encoding and convolutional encoding132 4.3.2 Channel decoding
132 4.3.3 Concatenated encoding133 4.3.4 Interleaving 1344.4
Channel coding and the powerbandwidth trade-off135 4.4.1 Coding
with variable bandwidth 135 4.4.2 Coding with constant bandwidth
137 4.4.3 Example: Downlink coding with on-board regeneration139
4.4.4 Conclusion 139 6. Contents vii 4.5 Coded modulation 1404.5.1
Trellis coded modulation1414.5.2 Block coded modulation1444.5.3
Decoding coded modulation 1454.5.4 Multilevel trellis coded
modulation 1454.5.5 TCM using a multidimensional signal set
1464.5.6 Performance of coded modulations146 4.6 End-to-end error
control 146 4.7 Digital video broadcasting via satellite (DVB-S)
1484.7.1 Transmission system 1484.7.2 Error performance
requirements152 4.8 Second generation DVB-S1524.8.1 New technology
in DVB-S21534.8.2 Transmission system architecture1544.8.3 Error
performance 156 4.9 Conclusion 1574.9.1 Digital transmission of
telephony 1574.9.2 Digital broadcasting of
television159References1605 UPLINK, DOWNLINK AND OVERALL LINK
PERFORMANCE;INTERSATELLITE LINKS163 5.1 Conguration of a link 163
5.2 Antenna parameters 1645.2.1 Gain1645.2.2 Radiation pattern and
angular beamwidth 1655.2.3 Polarisation168 5.3 Radiated power
1705.3.1 Effective isotropic radiated power (EIRP) 1705.3.2 Power
ux density 170 5.4 Received signal power1715.4.1 Power captured by
the receiving antenna and free space loss 1715.4.2 Example 1:
Uplink received power1725.4.3 Example 2: Downlink received
power1735.4.4 Additional losses 1745.4.5 Conclusion176 5.5 Noise
power spectral density at the receiver input 1765.5.1 The origins
of noise1765.5.2 Noise characterisation1775.5.3 Noise temperature
of an antenna 1805.5.4 System noise temperature1855.5.5 System
noise temperature: Example 1865.5.6 Conclusion186 5.6 Individual
link performance1865.6.1 Carrier power to noise power spectral
density ratio at receiver input 1875.6.2 Clear sky uplink
performance1875.6.3 Clear sky downlink performance189 5.7 Inuence
of the atmosphere 1935.7.1 Impairments caused by rain1935.7.2 Other
impairments 2075.7.3 Link impairmentsrelative importance209 7.
viiiContents 5.7.4Link performance under rain conditions209
5.7.5Conclusion2105.8 Mitigation of atmospheric impairments 210
5.8.1Depolarisation mitigation 210 5.8.2Attenuation mitigation211
5.8.3Site diversity211 5.8.4Adaptivity212 5.8.5Cost-availability
trade-off 2125.9 Overall link performance with transparent
satellite 213 5.9.1Characteristics of the satellite channel214
5.9.2Expression for (C/N0)T218 5.9.3Overall link performance for a
transparent satellite without interferenceor intermodulation221
5.10 Overall link performance with regenerative satellite225
5.10.1Linear satellite channel without interference226
5.10.2Non-linear satellite channel without interference227
5.10.3Non-linear satellite channel with interference 228 5.11 Link
performance with multibeam antenna coverage vs monobeamcoverage230
5.11.1Advantages of multibeam coverage 231 5.11.2Disadvantages of
multibeam coverage234 5.11.3Conclusion 237 5.12 Intersatellite link
performance 237 5.12.1Frequency bands238 5.12.2Radio-frequency
links238 5.12.3Optical links239 5.12.4Conclusion 245 References
2466 MULTIPLE ACCESS 2476.1 Layered data transmission 2476.2 Trafc
parameters 248 6.2.1Trafc intensity248 6.2.2Call blocking
probability 248 6.2.3Burstiness2486.3 Trafc routing249 6.3.1One
carrier per station-to-station link 250 6.3.2One carrier per
transmitting station251 6.3.3Comparison2516.4 Access techniques 251
6.4.1Access to a particular satellite channel (or transponder) 251
6.4.2Multiple access to the satellite channel252 6.4.3Performance
evaluationefciency2536.5 Frequency division multiple access (FDMA)
253 6.5.1TDM/PSK/FDMA254 6.5.2SCPC/FDMA 254 6.5.3Adjacent channel
interference 254 6.5.4Intermodulation 254 6.5.5FDMA efciency258
6.5.6Conclusion260 8. Contentsix 6.6 Time division multiple access
(TDMA) 2606.6.1 Burst generation2606.6.2 Frame structure 2626.6.3
Burst reception 2646.6.4 Synchronisation 2656.6.5 TDMA
efciency2706.6.6 Conclusion271 6.7 Code division multiple access
(CDMA) 2726.7.1 Direct sequence (DS-CDMA) 2736.7.2 Frequency
hopping CDMA (FH-CDMA)2766.7.3 Code generation 2776.7.4
Synchronisation 2786.7.5 CDMA efciency2806.7.6 Conclusion281 6.8
Fixed and on-demand assignment 2836.8.1 The principle 2836.8.2
Comparison between xed and on-demand assignment2836.8.3 Centralised
or distributed management of on-demand assignment 2846.8.4
Conclusion284 6.9 Random access2856.9.1 Asynchronous
protocols2866.9.2 Protocols with synchronisation2896.9.3 Protocols
with assignment on demand 290 6.10 Conclusion290References2917
SATELLITE NETWORKS293 7.1 Network reference models and protocols
2937.1.1 Layering principle2937.1.2 Open Systems Interconnection
(OSI) reference model2947.1.3 IP reference model295 7.2 Reference
architecture for satellite networks296 7.3 Basic characteristics of
satellite networks2987.3.1 Satellite network topology2987.3.2 Types
of link 3007.3.3 Connectivity300 7.4 Satellite on-board
connectivity3027.4.1 On-board connectivity with transponder
hopping3027.4.2 On-board connectivity with transparent processing
3037.4.3 On-board connectivity with regenerative processing3087.4.4
On-board connectivity with beam scanning313 7.5 Connectivity
through intersatellite links (ISL)3147.5.1 Links between
geostationary and low earth orbit satellites (GEOLEO)3147.5.2 Links
between geostationary satellites (GEOGEO)3147.5.3 Links between low
earth orbit satellites (LEOLEO)3187.5.4 Conclusion319 7.6 Satellite
broadcast networks 3197.6.1 Single uplink (one programme) per
satellite channel 3207.6.2 Several programmes per satellite
channel3217.6.3 Single uplink with time division multiplex (TDM) of
programmes3217.6.4 Multiple uplinks with time division multiplex
(TDM) of programmes on downlink 322 9. xContents 7.7 Broadband
satellite networks 3227.7.1 Overview of DVB-RCS and DVB-S/S2
network3247.7.2 Protocol stack architecture for broadband satellite
networks3257.7.3 Physical layer3267.7.4 Satellite MAC layer
3337.7.5 Satellite link control layer3387.7.6 Quality of
service3407.7.7 Network layer 3437.7.8 Regenerative satellite mesh
network architecture346 7.8 Transmission control protocol3517.8.1
TCP segment header format 3517.8.2 Connection set up and data
transmission 3527.8.3 Congestion control and ow control3537.8.4
Impact of satellite channel characteristics on TCP3547.8.5 TCP
performance enhancement 355 7.9 IPv6 over satellite networks
3567.9.1 IPv6 basics 3577.9.2 IPv6 transitions3587.9.3 IPv6
tunnelling through satellite networks3587.9.4 6to4 translation via
satellite networks 359 7.10 Conclusion359References3608 EARTH
STATIONS363 8.1 Station organisation 363 8.2 Radio-frequency
characteristics3648.2.1 Effective isotropic radiated power (EIRP)
3648.2.2 Figure of merit of the station3668.2.3 Standards dened by
international organisations and satellite operators 366 8.3 The
antenna subsystem3768.3.1 Radiation characteristics (main lobe)
3798.3.2 Side-lobe radiation 3798.3.3 Antenna noise temperature
3808.3.4 Types of antenna3858.3.5 Pointing angles of an earth
station antenna 3908.3.6 Mountings to permit antenna
pointing3938.3.7 Tracking399 8.4 The radio-frequency
subsystem4088.4.1 Receiving equipment 4088.4.2 Transmission
equipment4118.4.3 Redundancy417 8.5 Communication subsystems
4178.5.1 Frequency translation 4188.5.2 Amplication, ltering and
equalisation 4208.5.3 Modems421 8.6 The network interface
subsystem4258.6.1 Multiplexing and demultiplexing 4258.6.2 Digital
speech interpolation (DSI)4268.6.3 Digital circuit multiplication
equipment (DCME) 4278.6.4 Echo suppression and cancellation
4308.6.5 Equipment specic to SCPC transmission432 10. Contentsxi
8.7 Monitoring and control; auxiliary equipment 4328.7.1
Monitoring, alarms and control (MAC) equipment 4328.7.2 Electrical
power 4328.8 Conclusion 433References 4349 THE COMMUNICATION
PAYLOAD435 9.1 Mission and characteristics of the payload4359.1.1
Functions of the payload 4359.1.2 Characterisation of the
payload4369.1.3 The relationship between the radio-frequency
characteristics 437 9.2 Transparent repeater4379.2.1
Characterisation of non-linearities4389.2.2 Repeater
organisation4479.2.3 Equipment characteristics453 9.3 Regenerative
repeater 4659.3.1 Coherent demodulation4659.3.2 Differential
demodulation4669.3.3 Multicarrier demodulation466 9.4 Multibeam
antenna payload 4679.4.1 Fixed interconnection4679.4.2 Recongurable
(semi-xed) interconnection4689.4.3 Transparent on-board time domain
switching 4689.4.4 On-board frequency domain transparent
switching4719.4.5 Baseband regenerative switching4729.4.6 Optical
switching475 9.5 Introduction to exible payloads475 9.6 Solid state
equipment technology4779.6.1 The environment4779.6.2 Analogue
microwave component technology4779.6.3 Digital component technology
478 9.7 Antenna coverage4799.7.1 Service zone contour 4799.7.2
Geometrical contour4829.7.3 Global coverage4829.7.4 Reduced or spot
coverage 4849.7.5 Evaluation of antenna pointing error 4869.7.6
Conclusion 498 9.8 Antenna characteristics 4989.8.1 Antenna
functions4989.8.2 The radio-frequency coverage 5009.8.3 Circular
beams 5019.8.4 Elliptical beams 5049.8.5 The inuence of depointing
5059.8.6 Shaped beams 5079.8.7 Multiple beams 5109.8.8 Types of
antenna 5119.8.9 Antenna technologies 5159.9 Conclusion
524References 524 11. xiiContents10 THE PLATFORM 527 10.1
Subsystems528 10.2 Attitude control529 10.2.1 Attitude control
functions530 10.2.2 Attitude sensors531 10.2.3 Attitude
determination532 10.2.4 Actuators 534 10.2.5 The principle of
gyroscopic stabilisation 536 10.2.6 Spin stabilisation540 10.2.7
Three-axis stabilisation541 10.3 The propulsion subsystem547 10.3.1
Characteristics of thrusters547 10.3.2 Chemical propulsion 549
10.3.3 Electric propulsion 553 10.3.4 Organisation of the
propulsion subsystem558 10.3.5 Electric propulsion for station
keeping and orbit transfer561 10.4 The electric power supply 562
10.4.1 Primary energy sources562 10.4.2 Secondary energy sources567
10.4.3 Conditioning and protection circuits574 10.4.4 Example
calculations578 10.5 Telemetry, tracking and command (TTC) and
on-board data handling (OBDH) 580 10.5.1 Frequencies used581 10.5.2
The telecommand links 581 10.5.3 Telemetry links 582 10.5.4
Telecommand (TC) and telemetry (TM) message format standards583
10.5.5 On-board data handling (OBDH) 588 10.5.6 Tracking593 10.6
Thermal control and structure 596 10.6.1 Thermal control
specications 597 10.6.2 Passive control 598 10.6.3 Active
control601 10.6.4 Structure 601 10.6.5 Conclusion603 10.7
Developments and trends 604References60611 SATELLITE INSTALLATION
AND LAUNCH VEHICLES 607 11.1 Installation in orbit 607 11.1.1 Basic
principles607 11.1.2 Calculation of the required velocity
increments 609 11.1.3 Inclination correction and circularisation610
11.1.4 The apogee (or perigee) motor 617 11.1.5 Injection into
orbit with a conventional launcher 622 11.1.6 Injection into orbit
from a quasi-circular low altitude orbit 626 11.1.7 Operations
during installation (station acquisition)627 11.1.8 Injection into
orbits other than geostationary630 11.1.9 The launch window 631
11.2 Launch vehicles 631 11.2.1 Brazil632 11.2.2 China 635 12.
Contents xiii11.2.3 Commonwealth of Independent States (CIS)
63611.2.4 Europe 64111.2.5 India64811.2.6 Israel 64811.2.7
Japan64911.2.8 South Korea65211.2.9 United States of America 652
11.2.10 Reusable launch vehicles 660 11.2.11 Cost of installation
in orbit661 References 66112 THE SPACE ENVIRONMENT663 12.1
Vacuum663 12.1.1Characterisation 663 12.1.2Effects663 12.2 The
mechanical environment664 12.2.1The gravitational eld 664 12.2.2The
earths magnetic eld665 12.2.3Solar radiation pressure 666
12.2.4Meteorites and material particles667 12.2.5Torques of
internal origin 667 12.2.6The effect of communication
transmissions668 12.2.7Conclusions668 12.3 Radiation 668
12.3.1Solar radiation669 12.3.2Earth radiation671 12.3.3Thermal
effects671 12.3.4Effects on materials 672 12.4 Flux of high energy
particles 672 12.4.1Cosmic particles 672 12.4.2Effects on materials
674 12.5 The environment during installation 675 12.5.1The
environment during launching 676 12.5.2Environment in the transfer
orbit677References67713 RELIABILITY OF SATELLITE COMMUNICATIONS
SYSTEMS679 13.1 Introduction of reliability 679 13.1.1Failure rate
679 13.1.2The probability of survival or reliability 680
13.1.3Failure probability or unreliability 680 13.1.4Mean time to
failure (MTTF)682 13.1.5Mean satellite lifetime682
13.1.6Reliability during the wear-out period 682 13.2 Satellite
system availability 683 13.2.1No back-up satellite in orbit683
13.2.2Back-up satellite in orbit 684 13.2.3Conclusion 684 13.3
Subsystem reliability 685 13.3.1Elements in series 685 13. xiv
Contents 13.3.2 Elements in parallel (static redundancy) 685 13.3.3
Dynamic redundancy (with switching)687 13.3.4 Equipment having
several failure modes 69013.4 Component reliability 691 13.4.1
Component reliability691 13.4.2 Component selection692 13.4.3
Manufacture693 13.4.4 Quality assurance693INDEX697 14.
ACKNOWLEDGEMENTReproduction of gures extracted from the 1990
Edition of CCIR Volumes (XVIIthPlenary Assembly, D sseldorf, 1990),
the Handbook on Satellite Communications (ITUuGeneva, 1988) and the
ITU-R Recommendations is made with the authorisation of
theInternational Telecommunication Union (ITU) as copyright
holder.The choice of the excerpts reproduced remains the sole
responsibility of the authorsand does not involve in any way the
ITU.The complete ITU documentation can be obtained
from:International Telecommunication UnionGeneral Secretariat,
Sales SectionPlace des Nations, 1211 GENEVA 20, SwitzerlandTel: +41
22 730 51 11Tg: Burinterna GenevaTelefax: + 41 22 730 51 94 Tlx:
421 000 uit ch 15. ACRONYMSAAL ATM Adaptation LayerARTES Advanced
Research inA/D Analog-to-Digital conversionTElecommunications
SystemsABCSAdvanced Business Communications(ESA programme)via
Satellite ASCII American Standard Code forABM Apogee Boost
MotorInformation InterchangeACD Average Call Distance
ASICApplication Specic IntegratedACI Adjacent Channel Interference
CircuitACK ACKnowledgement ASN Acknowledgement SequenceACTSAdvanced
Communications NumberTechnology SatelliteASN Abstract Syntax
NotationADC Analog to Digital Converter ASTEAdvanced Systems andADM
Adaptive Delta Modulation Telecommunications EquipmentADPCM
Adaptive Pulse Code Modulation(ESA programme)ADSLAsymmetric Digital
Subscriber LineASTPAdvanced Systems and TechnologyAES Audio
Engineering Society Programme (ESA programme)AGCHAccess Granted
CHannelASYNC ASYNChronous data transferAKM Apogee Kick Motor ATA
Auto-Tracking AntennaALC Automatic Level Control ATC Adaptive
Transform CodingALG Application Level Gateway ATM Asynchronous
Transfer ModeAMAmplitude ModulationAMAPAdaptive Mobile Access
Protocol BAPTA Bearing and Power TransferAMP
AMPlierAssemblyAMPSAdvanced Mobile Phone Service BCH Broadcast
ChannelAMSCAmerican Mobile Satellite Corp. BCR Battery Charge
RegulatorAMSSAeronautical Mobile Satellite Service BDR Battery
Discharge RegulatorANSIAmerican National Standards BECNBackward
explicit congestionInstitute noticationAOCSAttitude and Orbit
Control System BEP Bit Error ProbabilityAOM Administration,
Operation and BER Bit Error RateMaintenance BFN Beam Forming
NetworkAOR Atlantic Ocean Region BFSKBinary Frequency Shift
KeyingAPC Adaptive Predictive CodingBGMPBorder Gateway MulticastAPD
Avalanche Photodetector ProtocolAPI Application Programming BGP
Border Gateway ProtocolInterface BHCABusy Hour Call AttemptsARAxial
Ratio BHCRBusy Hour Call RateARQ Automatic Repeat RequestBISDN
Broadband ISDNARQ-GB(N) Automatic repeat ReQuest-Go Back NBIS
Broadband Interactive SystemARQ-SRAutomatic repeat
ReQuest-SelectiveBITEBuilt-In Test EquipmentRepeatBOL Beginning of
LifeARCSAstra Return Channel System BPF Band Pass
FilterARQ-SWAutomatic repeat ReQuest-Stop and BPSKBinary Phase
Shift KeyingWaitBSBase Station 16. xviiiAcronymsBSC Binary
SynchronousCNESCentre National dEtudes SpatialesCommunications
(bisync) (French Space Agency)BSN Block Sequence Number CODLS
Connection Oriented Data LinkBSS Broadcasting Satellite
ServiceServiceBTBase TransceiverCOMETSCommunications and
BroadcastingBTS Base Transceiver StationEngineering Test
SatelliteBWBandWidth CONUS CONtinental USCoS Class of ServiceCAD
Computer Aided Design COSTEuropean COoperation in the eld ofCAM
Computer Aided ManufacturingScientic and Technical
researchCAMPChannel AMPlierCOTSCommercial Off The
ShelfCATVCAbleTeleVision CPS Chemical Propulsion
SystemCBDSConnectionless broadband data CRC Communications Research
Centreservice (Canada)CBO Continuous Bit Oriented CSCell
SelectionCBR Constant Bit Rate CSMACarrier Sense Multiple AccessCCI
CoChannel InterferenceCTCordless TelephoneCCIRComit Consultatif
International eCTR Common Technical Regulationdes
Radiocommunications CTU Central Terminal Unit(International Radio
ConsultativeCommittee)D-AMPSDigital Advanced Mobile PhoneCCITT
Comit Consultatif International du eSystemTlgraphe et du Tlphone
(TheeeeeD-M-PSK Differential M-ary Phase Shift KeyingInternational
Telegraph and D/C Down-ConverterTelephone Consultative Committee)
DADemand AssignmentCCSDS Consultative Committee for SpaceDAB
Digital Audio BroadcastingData SystemsDAC Digital to Analog
ConverterCCU Cluster Control UnitDAMADemand Assignment Multiple
AccessCDMACode Division Multiple Access DARPA Defense Advanced
Research ProjectCEC Commission of the EuropeanDASSDemand Assignment
Signalling andCommunities SwitchingCELPCode Excited Linear
PredictiondBdeciBelCENELEC Comit Europen pour la e edBm Unit for
expression of power level inNormalisation en ELECtrotechnique dB
with reference to 1 mW(European Committee for Electro-dBm Unit for
expression of power level intechnical Standardisation)dB with
reference to 1 mWCEPTConfrence Europenne des Postes et ee dBmOUnit
for expression of power level inTlcommunications (EuropeaneedBm at
a point of zero relative levelConference of Post and(a point of a
telephone channel whereTelecommunications) the 800 Hz test signal
has a power ofCFDMA Combined Free/Demand1 mW)Assignment Multiple
AccessDBF Digital Beam FormingCFM Companded Frequency
ModulationDBFNDigital Beam Forming NetworkCFRACombined
Fixed/ReservationDBS Direct Broadcasting
SatelliteAssignmentDCDirect CurrentCIR Committed Information
RateDCCHDedicated Control ChannelCIRFCo-channel Interference
Reduction DCE Data Circuit Terminating EquipmentFactorDCFLDirect
Coupled Fet LogicCIS Commonwealth of Independent DCMEDigital
Circuit MultiplicationStatesEquipmentCLDLS ConnectionLess Data Link
ServiceDCS Digital Cellular System (GSM At 1800CLECCompetitive
Local ExchangeMHz)Carrier DCT Discrete Cosine
TransformCLNPConnectionLess Network Protocol DCU Distribution
Control UnitCLTUCommand Link Transmission UnitDDCMP Digital Data
CommunicationsCMOSComplementary Metal Oxide Message Protocol (a DEC
Protocol)Semiconductor DEDifferentially Encoded 17.
AcronymsxixDE-M-PSK Differentially Encoded M-aryEUTELSAT European
Telecommunications Phase Shift Keying Satellite OrganisationDECT
Digital European Cordless Telephone FACFinal Assembly
CodeDEMODDEMODulator FCCFederal
CommunicationsDEMUXDEMUltipleXerCommissionDESData Encryption
StandardFCSFrame Check SequenceDM Delta ModulationFDDI Fibre
Distributed Data InterfaceDNSDomain Name Service (host
nameFDMFrequency Division Multiplex resolution protocol)FDMA
Frequency Division Multiple AccessDODDepth of DischargeFECForward
Error CorrectionDOFDegree of Freedom FESFixed Earth StationDQDB
Distributed Queue Dual BusFETField Effect TransistorDSCP
Differentiated Service Code Point FETA Field Effect Transistor
AmplierDSIDigital Speech InterpolationFFTFast Fourier
TransformDSLDigital Subscriber Loop FGMFixed Gain ModeDSPDigital
Signal Processing FIFO First In First OutDTEData Terminating
EquipmentFM Frequency ModulationDTHDirect To HomeFMAFixed-Mount
AntennaDTTL Data Transition Tracking Loop FMSFleet Management
ServiceDUTDevice Under Test FMTFade Mitigation TechniqueDVBDigital
Video BroadcastingFODA FIFO Ordered Demand AssignmentDWDM Dense
Wave Division MultiplexingFPGA Field Programmable Gate Array FPLMTS
Future Public Land MobileEA Early Assignment Telecommunications
SystemEBUEuropean Broadcasting Union FS Fixed ServiceEC European
CommunityFR Frame RelayECLEmitter Coupled Logic FSKFrequency Shift
KeyingEFSError Free SecondsFSSFixed Satellite ServiceEIAElectronic
Industries Association FTPFile Transfer ProtocolEIREquipment
Identity RegisterEIRP Effective Isotropic RadiatedGA ETSI General
Assembly Power (W) GaAs Gallium ArsenideELSR Edge Label Switch
RouterGBNGo Back NEMCElectroMagnetic CompatiblityGC Global
CoverageEMFElectroMagnetic Field GCEGround
CommunicationEMIElectroMagnetic Interference EquipmentEMSEuropean
Mobile Satellite GCSGround Control StationENRExcess Noise
RatioGDEGroup Delay EqualizerEOLEnd of Life GEOGeostationary Earth
OrbitEPCElectric Power ConditionerGMDSSGlobal Maritime Distress and
SafetyEPIRBEmergency Position Indicating RadioSystem BeamGOSGrade
Of ServiceERCEuropean RadiocommunicationsGPRS General Packet Radio
Service Committee GPSGlobal Positioning SystemERLEcho Return
LossGREGeneric Routing EncapsulationEROEuropean
RadiocommunicationsGSMGlobal System for Mobile Ofce (of the ERC)
communicationsES Earth Station GSOGeostationary Satellite
OrbitESAEuropean Space Agency GTOGeostationary Transfer
OrbitESTECEuropean Space Research and Technology Centre HDB3 High
Density Binary 3 codeETRETSI Technical Report HDLC High Level Data
Link ControlETSEuropean Telecommunications HDTV High Denition
TeleVision Standard, created within ETSI HEMT High Electron
Mobility TransistorETSI European Telecommunications HEOHighly
Elliptical Orbit Standards Institute HIOHighly Inclined Orbit 18.
xxAcronymsHIPERLAN HIgh PErformance Radio Local
AreaISOInternational Organisation for Network
StandardisationHLRHome Location Register ISSInter-Satellite
ServiceHPAHigh Power AmplierISUIridium Subscriber UnitHPBHalf Power
Beamwidth ITUInternational TelecommunicationHPTHand Held Personal
TelephoneUnionHTML Hyper Text Markup Language IUSInertial Upper
StageHTTP Hyper Text Transfer Protocol IVOD Interactive Video On
DemandIWUInternetWorking UnitIATInterarrival TimeIAUInternational
Astronomical UnitJDBC Java Database ConnectivityIBAIndependent
Broadcasting Authority JPEG Joint Photographic Expert GroupIBOInput
Back-offIBSInternational Business Service LA Location AreaICMP
Internet Control Message ProtocolLANLocal Area NetworkICIInterface
Control InformationLAPB Link Access Protocol
BalancedICOIntermediate Circular OrbitLDPLabel Distribution
ProtocolIGMP Internet Group Management Protocol LEOLow Earth
OrbitIDCIntermediate rate Digital CarrierLFSR Linear Feedback Shift
RegisterIDRIntermediate Data Rate LHCP Left Hand Circular
PolarizationIDUInterface Data Unit, also. InDoor Unit LLCLogical
Link ControlIEEE Institute of Electrical and Electronic LLMLband
Land Mobile EngineersLMDS Local Multipoint Distribution SystemIETF
Internet Engineering Task ForceLMSS Land Mobile Satellite
ServiceI-ETSInterim ETSLNALow Noise AmplierIF Intermediate
Frequency LNBLow Noise BlockIFRB International Frequency
Registration LO Local Oscillator BoardLOSLine of SightIGMP Internet
Group Management Protocol LPCLinear Predictive
CodingILSInternational Launch ServicesLPFLow Pass FilterIM
InterModulationLR Location RegisterIMPInterface Message
ProcessorLRELow Rate EncodingIMPInterModulation ProductLSPLabel
Switched PathIMSI International Mobile SubscriberLSRLabel Switching
Router Identity LU Location UpdatingIMUX Input MultiplexerIN
Intelligent NetworkM-PSKM-ary Phase Shift KeyingINIRIC
International Non-Ionising RadIation MACMedium Access Control
CommitteeMACMultiplexed Analog ComponentsINMARSAT International
Maritime Satellite(also Monitoring, Alarm and Control) Organisation
MACSAT Multiple Access SatelliteINTELSAT International
Telecommunications MAMA Multiple ALOHA Multiple Access Satellite
Consortium MANMetropolitan Area NetworkIORIndian Ocean RegionMCPC
Multiple Channels Per CarrierIOTIn Orbit TestMEBMegabit Erlang Bit
rateIP Internet Protocol (a network layer MEOMedium altitude Earth
Orbit datagram protocol) MESMobile Earth StationIPAIntermediate
Power AmplierMESFET Metal Semiconductor Field EffectIPEInitial
Pointing ErrorTransistorIPsecIP security policy MF
MultifrequencyIRCD Internet Relay Chat Program Server MHTMean
Holding Time (a teleconferencing application) MICMicrowave
Integrated CircuitIRDInternet Resources DatabaseMIDI Musical
Instrument Digital InterfaceIRDIntegrated Receiver DecoderMIFR
Master International FrequencyISDN Integrated Services Digital
Network RegisterISCInternational Switching Center MMDS Multipoint
Multichannel DistributionISLIntersatellite Link System 19. Acronyms
xxiMMIC Monolithic Microwave IntegratedPB Primary Body (orbits)
CircuitPBXPrivate (automatic) Branch eXchangeMODMODulatorPC
Personal ComputerMODEMModulator/DemodulatorPCCH Physical Control
CHannelMOSMean Opinion Score PCHPaging CHannelMOSMetal-Oxide
SemiconductorPCMPulse Code ModulationMoUMemorandum of
UnderstandingPCNPersonal Communications NetworkMPEG Motion Picture
Expert Group (often refers to DCS 1800)MPLS Multi-Protocol Label
Switching PCSPersonal Communications SystemMPSK M-ary Phase Shift
Keying PDCH Physical Data CHannelMS Mobile Station PDFProbability
Density FunctionMSCMobile Switching CenterPDHPlesiochronous Digital
HierarchyMSKMinimum Shift Keying PDUProtocol Data UnitMSSMobile
Satellite Service PFDPower Flux DensityMTBF Mean Time Between
FailurePHEMTPseudomorphic High ElectronMTPMessage Transfer Part
Mobility TransistorMTUMaximum Transferable UnitPHBPer Hop
BehaviourMUXMUltipleXerPHPPersonal Handy PhoneMX MiXerPHSPersonal
Handyphone SystemPICH PIlot ChannelNACK No ACKnowledgmentPILC
Performance Implication of LinkNASA National Aeronautics And
SpaceCharacteristics Administration (USA) PIMP Passive
InterModulation ProductNASDANational Aeronautics And Space
PKMPerigee Kick Motor Development Agency (Japan) PLLPhase Locked
LoopNATNetwork Address TranslationPLMN Public Land Mobile
NetworkNGSO Non-Geostationary Satellite OrbitPM Phase ModulationNH
Northern HemispherePMRPrivate Mobile RadioNISNetwork Information
System PN Personal NumberNMTNordic Mobile TelephonePODA Priority
Oriented DemandNNTP Network News Transfer ProtocolAssignmentNOAA
National Oceanic and Atmospheric POLPOLarisation Administration
PORPacic Ocean RegionNORM Nack-Oriented Reliable Multicast PP
Portable PartNSONational Standardisation PPPPoint to Point Protocol
Organisation PRMA Packet Reservation Multiple AccessNRZNon-Return
to Zero PSDPower Spectral DensityNTPNetwork Time ProtocolPSKPhase
Shift KeyingNVOD Near Video On Demand PSPDNPacket Switched Public
Data NetworkPSTN Public Switched Telephone NetworkOACSUOff-Air Call
Set-UpPTAProgramme Tracking AntennaOBCOn-Board ComputerPTNPublic
Telecommunications NetworkOBOOutput Back-OffPTOPublic
Telecommunications OperatorOBPOn-Board ProcessingPVAPerigee
Velocity AugmentationODUOutdoor Unit PVCPermanent Virtual
CircuitOICETS Optical Inter-orbit Communications Engineering Test
Satellite QoSQuality of ServiceOMUX Output MUltipleXer QPSK
Quaternary Phase Shift KeyingONPOpen Network ProvisionOSIOpen
System InterconnectionRAAN Right Ascension of the AscendingOSPF
Open Shortest Path FirstNodeRACE Research and development inPABX
Private Automatic Branch eXchange Advanced CommunicationsPACS
Personal Access Communications RACH Random Access Channel System
RADIUS Remote Authentication Dial In UserPADPacket
Assembler/Disassembler ServicePAMPayload Assist ModuleRAMRandom
Access Memory 20. xxiiAcronymsRAN Radio Area NetworkSFH Slow
Frequency HoppingRARCRegional Administrative Radio SHSouthern
HemisphereConferenceSHF Super High Frequency (3 GHz toRAS Radio
Astronomy Service 30 GHz)RCVOReceive OnlySIM Subscriber Identity
ModuleRCVRReCeiVeRS-ISUPSatellite ISDN User PartRDS Radio Data
System SIT Satellite Interactive TerminalRDSSRadio Determination
Satellite Service SKW Satellite-Keeping WindowRERadio
ExchangeSLSatelLiteRec RecommendationSLA Service Level AgreementRep
ReportSLICSubscriber Line Interface CardRES Radio Equipment
Systems,SMATV Satellite based Master Antenna for TVETSI Technical
CommitteedistributionRFRadio Frequency SME Small and Medium
EnterpriseRFHMA Random Frequency HoppingSMS Satellite
Multi-ServicesMultiple Access SMTPSimple Mail Transfer ProtocolRFI
Radio Frequency InterferenceSNA Systems Network Architecture
(IBM)RGS Route Guidance ServiceSNDCP SubNet Dependent
ConvergenceRHCPRight-Hand Circular PolarizationProtocolRIP Routing
Information ProtocolSNEKSatellite NEtworK node computerRLReturn
Loss SNG Satellite News GatheringRLANRadio Local Area
NetworkSNMPSimple Network ManagementRLL Radio in the Local Loop
ProtocolRLOGINRemote login applicationSNR Signal-to-Noise RatioRMA
Random Multiple AccessSOC State of ChargeRMTPRealisable Multicast
TransportSOHOSmall Ofce Home OfceProtocolSORASatellite Oriented
ResourceRNCCRegional Network Control Center AllocationRNR Receiver
Not ReadySORFStart of Receive FrameRORARegion Oriented Resource
Allocation SOTFStart of Transmit FrameRRRadio RegulationSPADE
Single-channel-per-carrier PCMRSReed Solomon (coding) multiple
Access Demand assignmentRSVPResource reSerVation Protocol
EquipmentRTCPReal Time transport Control ProtocolS-PCN Satellite
Personal CommunicationsRTP Real Time transport ProtocolNetworkRTU
Remote Terminal UnitS/PDIFSony/Philips Digital
InterfaceRXReceiverFormatSPDTSingle-Pole Double-Throw
(switch)S-ALOHA Slotted ALOHA protocolSPMTSingle-Pole
Multiple-Throw (switch)SAMASpread ALOHA Multiple AccessSPT
Stationary Plasma ThrusterSAP Service Access PointSPU Satellite
Position UncertaintySAW Surface Acoustic Wave SRSelective
RepeatSBSecondary Body (orbits) SSSatellite SwitchSBC Sub-Band
Coding SSB Single Side-BandSCSuppressed CarrierSSMASpread Spectrum
Multiple AccessS/C SpaceCraftSSO Sun-Synchronous OrbitSCADA
Supervisory Control and DataSSOGSatellite Systems Operations
GuideAcquisition (INTELSAT)SCCPSignalling Connection Control
PartSSP Signalling Switching PointSCH Synchronization CHannel
SSPASolid State Power AmplierSCP Service Control Point SS-TDMA
Satellite Switched TDMASCPCSingle Channel Per CarrierSTC ETSI
Sub-Technical CommitteeSDH Synchronous Digital Hierarchy STM
Synchronous Transport ModuleSDLCSynchronous Data Link Control STS
Space Transportation SystemSDU Service Data Unit SUSubscriber
UnitSEP Symbol Error ProbabilitySVC Switched Virtual CircuitSEU
Single Event UpsetSWSwitch 21. Acronyms xxiiiSW Stop and Wait
UMTSUniversal MobileSWRStanding Wave Ratio Telecommunications
SystemSYNC SYNChronisation UPS Uninterruptible Power Supply UPT
Universal PersonalTA ETSI Technical Assembly TelecommunicationsTACS
Total Access Communication System USATUltra Small Aperture
TerminalTBCTo Be ConrmedUSB Universal Serial BusTBDTo Be
DenedUWUnique WordTBRTechnical Basis
RegulationT/RTransmit/ReceiveVBR Variable Bit RateTC Telecommand
VCVirtual Channel (or Container)TCHTrafc CHannelVCI Virtual Channel
IdentierTCPTransmission Control Protocol VDSLVery high-speed
DigitalTDMTime Division Multiplex Subscriber LineTDMA Time Division
Multiple Access VHDLVHSIC Hardware DescriptionTDRS Tracking and
Data Relay Satellite LanguageTELNET remote terminal application
VHSIC Very High Speed IntegratedTEMTransverse
ElectroMagneticCircuitTETRATrans European Trunk RadioVHF Very High
Frequency (30 MHz toTFTS Terrestrial Flight Telephone System 300
MHz)TIATelecommunications Industry VLR Visitor Location Register
Association VLSIVery Large Scale IntegrationTIETerrestrial
Interface Equipment VOW Voice Order WireTM Telemetry VPA Variable
Power AttenuatorTM/TCTelemetry/Telecommand VPC Virtual Path
ConnectionTP4Transport Protocol Class 4VPD Variable Phase
DividerTPRTransponder VPS Variable Phase ShifterTRAC Technical
Recommendations VPI Virtual Path Identier Application Committee VPN
Virtual Private NetworkTTCTelemetry, Tracking and Command VSATVery
Small ApertureTTCM Telemetry, Tracking, Command andTerminal
MonitoringVSELP Vector Sum Excitation LinearTTLTransistor
Transistor Logic PredictionTTLTime To LiveVSWRVoltage Standing Wave
RatioTTYTelegraphYTV TeleVisionWAN Wide Area NetworkTWTTravelling
WaveTube WAP Wireless Application ProtocolTWTA Travelling WaveTube
AmplierWARCWorld Administrative RadioTx Transmitter Conference Web
Worldwide WebU/CUp-ConverterUDLR UniDirectional Link Routing XPD
Cross PolarizationUDPUser Datagram ProtocolDiscriminationUHFUltra
High Frequency (300 MHz toXPI Cross Polarisation Isolation 3
GHz)Xponder Transponder 22. NOTATIONaorbit semi-major axis
Eelevation angle (also energy and electricAazimuth angle (also
attenuation, area, eld strength) availability, trafc density and
carrierEb energy per information bit amplitude)Ec energy per
channel bitAeff effective aperture area of an antennaAAGattenuation
by atmospheric gasesffrequency (Hz)ARAINattenuation due to
precipitation andFc nominal carrier frequency cloudsfd antenna
focal lengthAP attenuation of radiowave by rain forfm frequency of
a modulating sine wave percentage p of an average year fmax maximum
frequency of the modulatingbaseband signal spectrumBbandwidth fD
downlink frequencybvoice channel bandwidth (3100 Hz from fU uplink
frequency 300 to 3400 Hz) Fnoise gureBn noise measurement bandwidth
atDFmaxpeak frequency deviation of a frequency baseband (receiver
output) modulated carrierBN equivalent noise bandwidth of fS
sampling frequency receiverBu burstinessgpeak factor Gpower gain
(also gravitational constant)cvelocity of light 3 108 m=s Gsat gain
at saturationCcarrier power GR receiving antenna gain in direction
ofC=N0 carrier power-to-noise power spectraltransmitter density
ratio (W/Hz)GT transmitting antenna gain in direction ofC=N0 U
uplink carrier power-to-noise powerreceiver spectral density
ratioGRmaxmaximum receiving antenna gainC=N0 D downlink carrier
power-to-noise power GTmaxmaximum transmitting antenna gain
spectral density ratioGSRsatellite repeater gainC=N0 IMcarrier
power-to-intermodulation noiseGSRsat saturation gain of satellite
repeater power spectral density ratioG/Tgain to system noise
temperature ratio ofC=N0 I carrier power-to-interference noisea
receiving equipment power spectral density ratioGCAchannel
amplierC=N0 I;U uplink carrier power-to-interferenceGFEfront end
gain from satellite receiver noise power spectral density ratio
input to satellite channel amplier inputC=N0 I;D downlink carrier
power-to-interferenceGsssmall signal power gain noise power
spectral density ratioC=N0 T carrier power-to-noise power spectral
iinclination of the orbital plane density ratio for total link
kBoltzmanns constant Ddiameter of a reector antenna (also used1:379
1023 W=KHz as a subscript for downlink)kFMFM modulation frequency
deviationconstant (MHz/V)eorbit eccentricitykPMPM phase deviation
constant (rad/V) 23. xxvi NotationKPAM/PM conversion coefcient Pi
ninput power in a multiple carrierKTAM/PM transfer coefcient
operation mode (n carriers)Po noutput power in a multiple carrierl
earth station latitudeoperation mode (n carriers)L earth
station-to-satellite relative PIMX npower of intermodulation
product oflongitude also loss in link budgetorder X at output of a
non-linear devicecalculations, and loading factor of FDM/in a
multicarrier operation modeFM multiplex also message length (bits)
(n carriers)Leeffective path length of radiowavethrough rain (km) Q
quality factorLFRXreceiver feeder lossLFTXtransmitter feeder loss r
distance between centre of mass (orbits)LFS free space loss R slant
range from earth station to satelliteLPOINTdepointing loss (km)
(also symbol or bit rate)LPOLantenna polarisation mismatch
lossRbinformation bit rate (s1 )LRreceiving antenna depointing loss
Rcchannel bit rate (s1 )LTtransmitting antenna depointing lossRcall
mean number of calls per unit timeREearth radius 6378 kmm satellite
massRogeostationary satellitemcpower reduction associated with
altitude 35 786 kmmulticarrier operationRprainfall rate (mm/h)
exceeded for timeM mass of the earth (kg) (also number ofpercentage
p of a yearpossible states of a digital signal)Rssymbol (or
signalling) rate (s1 )N0noise power spectral density (W/Hz) S user
signal power (W)N0 Uuplink noise power spectral density S/N
signal-to-noise power ratio at users end(W/Hz)N0 Ddownlink noise
power spectral density T period of revolution (orbits)
(s)(W/Hz)(also noise temperature (K))N0 Ttotal link noise power
spectral density TAantenna noise temperature (K)(W/Hz)TAMBambient
temperature (K)N0 Iinterference power spectral density
Tbinformation bit duration (s)(W/Hz)TBburst duration (s)N noise
power (W) (also number of stationsTcchannel bit duration (s)in a
network) Teeffective input noise temperature of afour port element
system (K)p pre-emphasis/companding TEmean sidereal day
86164:15improvement factor (also rainfall TeATT effective input
noise temperature of anannual percentage)attenuator (K)pwrainfall
worst month time percentageTeRxeffective input noise temperature of
aP power (also number of bursts in a TDMAreceiverframe)TFframe
duration (s) (also feederPbinformation bit error
ratetemperature)Pcchannel bit error rateTmeffective medium
temperature (K)PHPArated power of high power amplier (W)T0reference
temperature (290 K)PTpower fed to the antenna (W)TeRXeffective
input noise temperature of aPTx transmitter power (W) receiver
(K)PRreceived power (W)TSsymbol duration (s)PRx power at receiver
input (W) TSKYclear key contribution to antenna noisePis input
power in a single carrier operation temperature (K)modeTGROUND
ground contribution to antenna noisePo 1output power in a single
carriertemperature (K)operation mode(Pi 1)sat input power in a
single carrier operation U subscript for uplinkmode at saturationv
true anomaly (orbits)(Po 1)sat saturation output power in a
singlecarrier operation modeVssatellite velocity (m/s) 24. Notation
xxviiVLp/p peak-to-peak luminance voltage (V)G 6:67 1011 m3 kg1 s2
,VTp/p peak-to-peak total video signal voltage M 5:974 1024
kg;(including synchronisation pulses)m GM 3:986 1014 m3
s2VNmsroot-mean-square noise voltage (V) rcode rate
sStefanBoltzmann constant w psophometric weighting factor 5:67 108
Wm2 K4 fsatelliteearth station angle from theX intermodulation
product order (IMX) earths centre Fpower ux density (w/m2)a angle
from boresight of antennaFmax max maximum power ux density atg
vernal pointtransmit antenna boresightG spectral efciency (bit/s
Hz)Fnom nom nominal power ux densityd declination angle (also
delay)at receive end required to build uph antenna aperture
efciencya given power assuming maximuml wavelength ( c=f ) also
longitude, alsoreceive gain (no depointing)message generation rate
(s1 ) Fsat power ux density required to operatew latitudereceive
amplier at saturationt propagation time cpolarisation angleu3dBhalf
power beamwidth of an antenna vargument of perigeewavelength c=f
Wright ascension of the ascendinguRreceiving antenna pointing
errornodeuTtransmit antenna pointing errorWE angular velocity of
rotation of the earthm GM G gravitational constant, earth 15:0469
deg=hr M mass of earth;4:17103 deg=s7:292105 rad=s 25. 1
INTRODUCTIONThis chapter describes the characteristics of satellite
communication systems. It aims to satisfythe curiosity of an
impatient reader and facilitate a deeper understanding by directing
him or herto appropriate chapters without imposing the need to read
the whole work from beginning to end.1.1BIRTH OF SATELLITE
COMMUNICATIONSSatellite communications are the outcome of research
in the area of communications and spacetechnologies whose objective
is to achieve ever increasing ranges and capacities with the
lowestpossible costs.The Second World War stimulated the expansion
of two very distinct technologiesmissilesand microwaves. The
expertise eventually gained in the combined use of these two
techniquesopened up the era of satellite communications. The
service provided in this way usefullycomplements that previously
provided exclusively by terrestrial networks using radio and
cables.The space era started in 1957 with the launching of the rst
articial satellite (Sputnik).Subsequent years have been marked by
various experiments including the following: Christmasgreetings
from President Eisenhower broadcast by SCORE (1958), the reecting
satellite ECHO(1960), store-and-forward transmission by the COURIER
satellite (1960), powered relay satellites(TELSTAR and RELAY in
1962) and the rst geostationary satellite SYNCOM (1963).In 1965,
the rst commercial geostationary satellite INTELSAT I (or Early
Bird) inauguratedthe long series of INTELSATs; in the same year,
the rst Soviet communications satellite of theMOLNYA series was
launched. 1.2DEVELOPMENT OF SATELLITE COMMUNICATIONSThe rst
satellites provided a low capacity at a relatively high cost; for
example, INTELSAT Iweighed 68 kg at launch for a capacity of 480
telephone channels and an annual cost of $32 500 perchannel at the
time. This cost resulted from a combination of the cost of the
launcher, that of thesatellite, the short lifetime of the satellite
(1.5 years) and its low capacity. The reduction in cost isthe
result of much effort which has led to the production of reliable
launchers which can putheavier and heavier satellites into orbit
(typically 5900 kg at launch in 1975, reaching 10 500 kg byAriane 5
ECA and 13 000 kg by Delta IV in 2008). In addition, increasing
expertise in microwavetechniques has enabled realisation of
contoured multibeam antennas whose beams adapt to theshape of
continents, frequency re-use from one beam to the other and
incorporation of higherSatellite Communications Systems, Fifth
Edition Grard Maral, Michel Bousquet and Zhili Sun e 2009 John
Wiley & Sons, Ltd. 26. 2Introductionpower transmission
ampliers. Increased satellite capacity has led to a reduced cost
per telephonechannel. In addition to the reduction in the cost of
communication, the most outstanding feature is thevariety of
services offered by satellite communications systems. Originally
these were designedto carry communications from one point to
another, as with cables, and the extended coverage ofthe satellite
was used to set up long distance links; hence Early Bird enabled
stations on oppositesides of the Atlantic Ocean to be connected.
However, as a consequence of the limited performanceof the
satellite, it was necessary to use earth stations equipped with
large antennas and therefore ofhigh cost (around $10 million for a
station equipped with a 30m diameter antenna). The increasing size
and power of satellites has permitted a consequent reduction in the
size ofearth stations, and hence their cost, leading to an increase
in number. In this way it has beenpossible to exploit another
feature of the satellite which is its ability to collect or
broadcast signalsfrom or to several locations. Instead of
transmitting signals from one point to another, transmissioncan be
from a single transmitter to a large number of receivers
distributed over a wide area or,conversely, transmission can be
from a large number of stations to a single central station,
oftencalled a hub. In this way, multipoint data transmission
networks and data collection networkshave been developed under the
name of VSAT (very small aperture terminals) networks [MAR-95].Over
1 000 000 VSATs have been installed up to 2008. For TV services,
satellites are of paramountimportance for satellite news gathering
(SNG), for the exchange of programmes between broad-casters, for
distributing programmes to terrestrial broadcasting stations and
cable heads,or directly to the individual consumer. The latter are
commonly called direct broadcasting bysatellite (DBS) systems, or
direct-to-home (DTH) systems. A rapidly growing service is
digitalvideo broadcasting by satellite (DVB-S), developed in early
1991; the standard for the secondgeneration (DVB-S2) has been
standardised by the European Telecommunication StandardInstitute
(ETSI). These DBS systems operate with small earth stations having
antennas with adiameter from 0.5 to 1 m. In the past, the customer
stations were Receive Only (RCVO) stations. With the introduction
oftwo-way communications stations, satellites are a key component
in providing interactive TVand broadband Internet services thanks
to the implementation of the DVB satellite return channel(DVB-RCS)
standard to the service providers facilities. This uses TCP/IP to
support Internet,multicast and web-page caching services over
satellite with forward channel operating at severalMbit/s and
enables satellites to provide broadband service applications for
the end user, such asdirect access and distribution services.
IP-based triple-play services (telephony, Internet and TV)are more
and more popular. Satellites cannot compete with terrestrial
Asymmetric DigitalSubscriber Line (ADSL) or cable to deliver these
services in high-density population areas.However, they complement
nicely the terrestrial networks around cities and in rural areas
whenthe distance to the telephone router is too large to allow
delivery of the several Mbit/s required torun the service. A
further reduction in the size of the earth station antenna is
exemplied in digital audiobroadcasting (DAB) systems, with antennas
in the order of 10 cm. The satellite transmits multi-plexed digital
audio programmes and supplements traditional Internet services by
offering one-way broadcast of web-style content to the receivers.
Finally, satellites are effective in mobile communications. Since
the end of the 1970s, INMARSATsatellites have been providing
distress signal services along with telephone and data
commu-nications services to ships and planes and, more recently,
communications to portable earthstations (Mini M or Satphone).
Personal mobile communication using small handsets is availablefrom
constellations of non-geostationary satellites (such as Iridium and
Globalstar) and geosta-tionary satellites equipped with very large
deployable antennas (typically 10 to 15 m) as with theTHURAYA,
ACES, and INMARSAT 4 satellites. The next step in bridging the gaps
between xed,mobile and broadcasting radiocommunications services
concerns satellite multimedia broadcastto xed and mobile users.
Satellite digital mobile broadcasting (SDMB) is based on
hybridintegrated satelliteterrestrial systems to serve small
hand-held terminals with interactivity. 27. Conguration of a
Satellite Communications System 3 1.3 CONFIGURATION OF A
SATELLITECOMMUNICATIONS SYSTEMFigure 1.1 gives an overview of a
satellite communication system and illustrates its interfacingwith
terrestrial entities. The satellite system is composed of a space
segment, a control segment anda ground segment: The space segment
contains one or several active and spare satellites organised into
a constellation. The control segment consists of all ground
facilities for the control and monitoring of the satellites,also
named TTC (tracking, telemetry and command) stations, and for the
management of thetrafc and the associated resources on-board the
satellite.Figure 1.1 Satellite communications system, interfacing
with terrestrial entities. 28. 4Introduction The ground segment
consists of all the trafc earth stations. Depending on the type of
serviceconsidered, these stations can be of different size, from a
few centimetres to tens of metres.Table 1.1 gives examples of trafc
earth stations in connection with the types of service discussedin
Section 1.7. Earth stations come in three classes as illustrated in
Figure 1.1: user stations, such ashandsets, portables, mobile
stations and very small aperture terminals (VSATs), which allow
thecustomer direct access to the space segment; interface stations,
known as gateways, which inter-connect the space segment to a
terrestrial network; and service stations, such as hub or
feederstations, which collect or distribute information from and to
user stations via the space segment. Communications between users
are set up through user terminals which consist of equipmentsuch as
telephone sets, fax machines and computers that are connected to
the terrestrial networkor to the user stations (e.g. a VSAT), or
are part of the user station (e.g. if the terminal is mobile). The
path from a source user terminal to a destination user terminal is
named a simplexconnection. There are two basic schemes: single
connection per carrier (SCPC), where the modulatedcarrier supports
one connection only, and multiple connections per carrier (MCPC),
where themodulated carrier supports several time or frequency
multiplexed connections. Interactivitybetween two users requires a
duplex connection between their respective terminals, i.e.
twosimplex connections, each along one direction. Each user
terminal should then be capable ofsending and receiving
information. A connection between a service provider and a user
goes through a hub (for collecting services)or a feeder station
(e.g. for broadcasting services). A connection from a gateway, hub
or feederstation to a user terminal is called a forward connection.
The reverse connection is the returnconnection. Both forward and
return connections entail an uplink and a downlink, and possiblyone
or more intersatellite links. Table 1.1 Services from different
types of trafc earth stationType of service Type of earth
stationTypical size (m)Point-to-pointGateway,
hub210VSAT12Broadcast/multicast Feeder station15VSAT0.51.0Collect
VSAT0.11.0Hub 210MobileHandset, portable, mobile 0.10.5Gateway 210
1.3.1 Communications linksA link between transmitting equipment and
receiving equipment consists of a radio or opticalmodulated
carrier. The performance of the transmitting equipment is measured
by its effectiveisotropic radiated power (EIRP), which is the power
fed to the antenna multiplied by the gain of theantenna in the
considered direction. The performance of the receiving equipment is
measuredby G/T, the ratio of the antenna receive gain, G, in the
considered direction and the system noisetemperature, T; G/T is
called the receivers gure of merit. These concepts are detailed in
Chapter 5. The types of link shown in Figure 1.1 are: the uplinks
from the earth stations to the satellites; the downlinks from the
satellites to the earth stations; the intersatellite links, between
the satellites. 29. Conguration of a Satellite Communications
System 5Uplinks and downlinks consist of radio frequency modulated
carriers, while intersatellite links canbe either radio frequency
or optical. Carriers are modulated by baseband signals
conveyinginformation for communications purposes. The link
performance can be measured by the ratio of the received carrier
power, C, to the noisepower spectral density, N0, and is denoted as
the C/N0 ratio, expressed in hertz (Hz). The valuesof C/N0, for the
links which participate in the connection between the end
terminals, determinethe quality of service, specied in terms of bit
error rate (BER) for digital communications. Another parameter of
importance for the design of a link is the bandwidth, B, occupied
bythe carrier. This bandwidth depends on the information data rate,
the channel coding rate(forward error correction) and the type of
modulation used to modulate the carrier. For satellitelinks, the
trade-off between required carrier power and occupied bandwidth is
paramount tothe cost-effective design of the link. This is an
important aspect of satellite communications aspower impacts both
satellite mass and earth station size, and bandwidth is constrained
byregulations. Moreover, a service provider who rents satellite
transponder capacity from thesatellite operator is charged
according to the highest share of either power or bandwidthresource
available from the satellite transponder. The service providers
revenue is based onthe number of established connections, so the
objective is to maximise the throughput of theconsidered link while
keeping a balanced share of power and bandwidth usage. This is
discussedin Chapter 4. In a satellite system, several stations
transmit their carriers to a given satellite, therefore
thesatellite acts as a network node. The techniques used to
organise the access to the satellite by thecarriers are called
multiple access techniques (Chapter 6).1.3.2 The space segmentThe
satellite consists of the payload and the platform. The payload
consists of the receiving andtransmitting antennas and all the
electronic equipment which supports the transmission of
thecarriers. The two types of payload organisation are illustrated
in Figure 1.2. Figure 1.2a shows a transparent payload (sometimes
called a bent pipe type) where carrierpower is amplied and
frequency is downconverted. Power gain is of the order of 100130
dB,required to raise the power level of the received carrier from a
few tens of picowatts to the powerlevel of the carrier fed to the
transmit antenna of a few watts to a few tens of watts.
Frequencyconversion is required to increase isolation between the
receiving input and the transmittingoutput. Due to technology power
limitations, the overall satellite payload bandwidth is split
intoseveral sub-bands, the carriers in each sub-band being amplied
by a dedicated power amplier.The amplifying chain associated with
each sub-band is called a satellite channel, or transponder.
Thebandwidth splitting is achieved using a set of lters called the
input multiplexer (IMUX). Theamplied carriers are recombined in the
output multiplexer (OMUX). The transparent payload in Figure 1.2a
belongs to a single beam satellite where each transmitand receive
antenna generates one beam only. One could also consider multiple
beam antennas.The payload would then have as many inputs/outputs as
upbeams/downbeams. Routing ofcarriers from one upbeam to a given
downbeam implies either routing through different
satellitechannels, transponder hopping, depending on the selected
uplink frequency or on-board switchingwith transparent on-board
processing. These techniques are presented in Chapter 7. Figure
1.2b shows a multiple beam regenerative payload where the uplink
carriers are demo-dulated. The availability of the baseband signals
allows on-board processing and routing ofinformation from upbeam to
downbeam through on-board switching at baseband. The
frequencyconversion is achieved by modulating on-board-generated
carriers at downlink frequency. Themodulated carriers are then
amplied and delivered to the destination downbeam. Figure 1.3
illustrates a multiple beam satellite antenna and its associated
coverage areas.Each beam denes a beam coverage area, also called
footprint, on the earth surface. The aggregate 30. 6
IntroductionFigure 1.2 Payload organisation: (a) transparent and
(b) regenerative.beam coverage areas dene the multibeam antenna
coverage area. A given satellite may have severalmultiple beam
antennas, and their combined coverage denes the satellite coverage
area.Figure 1.4 illustrates the concept of instantaneous system
coverage and long-term coverage. Theinstantaneous system coverage
consists of the aggregation at a given time of the coverage areas
ofthe individual satellites participating in the constellation. The
long-term coverage is the area on theearth scanned over time by the
antennas of the satellites in the constellation.The coverage area
should encompass the service zone, which corresponds to the
geographicalregion where the stations are installed. For real-time
services, the instantaneous system coverage 31. Conguration of a
Satellite Communications System7Satellite antennamultibeam
antennacoveragebeam coverageFigure 1.3 Multiple beam satellite
antenna and associated coverage area.Figure 1.4 Types of coverage.
32. 8IntroductionTable 1.2 Platform subsystemSubsystem Principal
functions CharacteristicsAttitude and orbit controlAttitude
stabilisation, orbit Accuracy(AOCS)determinationPropulsionProvision
of velocity incrementsSpecic impulse, mass ofpropellantElectric
power supply Provision of electrical energyPower, voltage
stabilityTelemetry, tracking and Exchange of housekeepingNumber of
channels, security ofcommand (TTC) information
communicationsThermal control Temperature maintenance Dissipation
capabilityStructure Equipment support Rigidity, lightnessshould at
any time have a footprint covering the service zone, while for
non-real-time (store-and-forward) services, it should have
long-term coverage of the service zone. The platform consists of
all the subsystems which permit the payload to operate. Table 1.2
liststhese subsystems and indicates their respective main functions
and characteristics. The detailed architecture and technology of
the payload equipment are explained in Chapter 9.The architecture
and technologies of the platform are considered in Chapter 10. The
operationsof orbit injection and the various types of launcher are
the subject of Chapter 11. The spaceenvironment and its effects on
the satellite are presented in Chapter 12. To ensure a service with
a specied availability, a satellite communication system must
makeuse of several satellites in order to ensure redundancy. A
satellite can cease to be available due to afailure or because it
has reached the end of its lifetime. In this respect it is
necessary to distinguishbetween the reliability and the lifetime of
a satellite. Reliability is a measure of the probability ofa
breakdown and depends on the reliability of the equipment and any
schemes to provideredundancy. The lifetime is conditioned by the
ability to maintain the satellite on station in thenominal
attitude, and depends on the quantity of fuel available for the
propulsion system andattitude and orbit control. In a system,
provision is generally made for an operational satellite,a backup
satellite in orbit and a backup satellite on the ground. The
reliability of the systemwill involve not only the reliability of
each of the satellites but also the reliability of launching.An
approach to these problems is treated in Chapter 13.1.3.3 The
ground segmentThe ground segment consists of all the earth
stations; these are most often connected to the end-users terminal
by a terrestrial network or, in the case of small stations (Very
Small ApertureTerminal, VSAT), directly connected to the end-users
terminal. Stations are distinguished by theirsize which varies
according to the volume of trafc to be carried on the satellite
link and the typeof trafc (telephone, television or data). In the
past, the largest were equipped with antennas of30 m diameter
(Standard A of the INTELSAT network). The smallest have 0.6 m
antennas(receiving stations from direct broadcasting satellites) or
even smaller (0.1 m) antennas (mobilestations, portable stations or
handsets). Some stations both transmit and receive. Others are
receive-only (RCVO) stations; this is the case, for example, with
receiving stations for a broadcastingsatellite system or a
distribution system for television or data signals. Figure 1.5
shows the typicalarchitecture of an earth station for both
transmission and reception. Chapter 5 introducesthe characteristic
parameters of the earth station which appear in the link budget
calculations.Chapter 3 presents the characteristics of signals
supplied to earth stations by the user terminaleither directly or
through a terrestrial network, the signal processing at the station
(such as sourcecoding and compression, multiplexing, digital speech
interpolation, channel coding, scrambling 33. Types of Orbit
9Antenna axis Elevation angle E Local horizonPOWERSUPPLYMONITORING
DIPLEXER TRACKING & CONTROLRF Baseband signalsHIGH POWERIF
(from users) AMPLIFIER MODULATOR RFBaseband signals FRONT END IF(to
users) (low noise amp) DEMODULATORFigure 1.5 The organisation of an
earth station. RF radio frequency, IF intermediate frequency.and
encryption), and transmission and reception (including modulation
and demodulation).Chapter 8 treats the organisation and equipment
of earth stations. 1.4TYPES OF ORBITThe orbit is the trajectory
followed by the satellite. The trajectory is within a plane and
shaped asan ellipse with a maximum extension at the apogee and a
minimum at the perigee. The satellitemoves more slowly in its
trajectory as the distance from the earth increases. Chapter 2
providesa denition of the orbital parameters.The most favourable
orbits are as follows: Elliptical orbits inclined at an angle of 64
with respect to the equatorial plane. This type of orbitis
particularly stable with respect to irregularities in terrestrial
gravitational potential and,owing to its inclination, enables the
satellite to cover regions of high latitude for a large fractionof
the orbital period as it passes to the apogee. This type of orbit
has been adopted by the USSRfor the satellites of the MOLNYA system
with period of 12 hours. Figure 1.6 shows the geometryof the orbit.
The satellite remains above the regions located under the apogee
for a time intervalof the order of 8 hours. Continuous coverage can
be ensured with three phased satellites ondifferent orbits. Several
studies relate to elliptical orbits with a period of 24 h (TUNDRA
orbits)or a multiple of 24 h. These orbits are particularly useful
for satellite systems for communicationwith mobiles where the
masking effects caused by surrounding obstacles such as
buildingsand trees and multiple path effects are pronounced at low
elevation angles (say less than 30 ). 34. 10IntroductionFigure 1.6
The orbit of a MOLNYA satellite.In fact, inclined elliptic orbits
can provide the possibility of links at medium latitudes whenthe
satellite is close to the apogee with elevation angles close to 90
; these favourable conditionscannot be provided at the same
latitudes by geostationary satellites. In the late 1980s,
theEuropean Space Agency (ESA) studied the use of elliptical highly
inclined orbits (HEO) fordigital audio broadcasting (DAB) and
mobile communications in the framework of its Archi-medes
programme. The concept became reality at the end of the 1990s with
the Sirius systemdelivering satellite digital audio radio services
to millions of subscribers (mainly automobiles)in the United States
using three satellites on HEO Tundra-like orbits [AKT-08]. Circular
low earth orbits (LEO). The altitude of the satellite is constant
and equal to severalhundreds of kilometres. The period is of the
order of one and a half hours. With near 90inclination, this type
of orbit guarantees worldwide long term coverage as a result of
thecombined motion of the satellite and earth rotation, as shown in
Figure 1.7. This is the reason forchoosing this type of orbit for
observation satellites (for example, the SPOT satellite:
altitude830 km, orbit inclination 98.7 , period 101 minutes). One
can envisage the establishment of store-and-forward communications
if the satellite is equipped with a means of storing information.A
constellation of several tens of satellites in low altitude (e.g.
IRIDIUM with 66 satellites at780 km) circular orbits can provide
worldwide real-time communication. Non-polar orbitswith less than
90 inclination, can also be envisaged. For instance the GLOBALSTAR
constella-tion incorporates 48 satellites at 1414 km with 52 orbit
inclination. 35. Types of Orbit11Figure 1.7 Circular polar low
earth orbit (LEO). Circular medium earth orbits (MEO), also called
intermediate circular orbits (ICO), havean altitude of about 10 000
km and an inclination of about 50 . The period is 6 hours.
Withconstellations of about 10 to 15 satellites, continuous
coverage of the world is guaranteed,allowing worldwide real-time
communications. A planned system of this kind was the ICOsystem
(which emerged from Project 21 of INMARSAT but was not implemented)
with aconstellation of 10 satellites in two planes at 45
inclination. Circular orbits with zero inclination (equatorial
orbits). The most popular is the geostationarysatellite orbit; the
satellite orbits around the earth in the equatorial plane according
to the earthrotation at an altitude of 35 786 km. The period is
equal to that of the rotation of the earth. Thesatellite thus
appears as a point xed in the sky and ensures continuous operation
as a radiorelay in real time for the area of visibility of the
satellite (43% of the earths surface). Hybrid systems. Some systems
may include combinations of orbits with circular and
ellipticalorbits. Such a design was envisaged for the ELLIPSO
system.The choice of orbit depends on the nature of the mission,
the acceptable interference and theperformance of the launchers:
The extent and latitude of the area to be covered; contrary to
widespread opinion, the altitude ofthe satellite is not a
determining factor in the link budget for a given earth coverage.
Chapter 5shows that the propagation attenuation varies as the
inverse square of the distance and thisfavours a satellite
following a low orbit on account of its low altitude; however, this
disregardsthe fact that the area to be covered is then seen through
a larger solid angle. The result isa reduction in the gain of the
satellite antenna which offsets the distance advantage. Now
asatellite following a low orbit provides only limited earth
coverage at a given time and limitedtime at a given location.
Unless low gain antennas (of the order of a few dB) which
providelow directivity and hence almost omnidirectional radiation
are installed, earth stations must be 36. 12Introductionequipped
with satellite tracking devices which increase the cost. The
geostationary satellite thusappears to be particularly useful for
continuous coverage of extensive regions. However, it doesnot
permit coverage of the polar regions which are accessible by
satellites in inclined ellipticalorbits or polar orbits. The
elevation angle; a satellite in an inclined or polar elliptical
orbit can appear overhead atcertain times which enables
communication to be established in urban areas without
encoun-tering the obstacles which large buildings constitute for
elevation angles between 0 andapproximately 70 . With a
geostationary satellite, the angle of elevation decreases as
thedifference in latitude or longitude between the earth station
and the satellite increases. Transmission duration and delay; the
geostationary satellite provides a continuous relay forstations
within visibility but the propagation time of the waves from one
station to the other isof the order of 0.25 s. This requires the
use of echo control devices on telephone channels orspecial
protocols for data transmission. A satellite moving in a low orbit
confers a reducedpropagation time. The transmission time is thus
low between stations which are close andsimultaneously visible to
the satellite, but it can become long (several hours) for distant
stationsif only store-and-forward transmission is considered.
Interference; geostationary satellites occupy xed positions in the
sky with respect to the stationswith which they communicate.
Protection against interference between systems is ensured
byplanning the frequency bands and orbital positions. The small
orbital spacing between adjacentsatellites operating at the same
frequencies leads to an increase in the level of interferenceand
this impedes the installation of new satellites. Different systems
could use differentfrequencies but this is restricted by the
limited number of frequency bands assigned for
spaceradiocommunications by the Radiocommunication Regulations. In
this context, one can refer toan orbit-spectrum resource which is
limited. With orbiting satellites, the geometry of eachsystem
changes with time and the relative geometries of one system with
respect to anotherare variable and difcult to synchronise. The
probability of interference is thus high. The performance of
launchers; the mass which can be launched decreases as the
altitudeincreases.The geostationary satellite is certainly the most
popular. At the present time there are around600 geostationary
satellites in operation within the 360 of the whole orbital arc.
Some parts of thisorbital arc, however, tend to be highly congested
(for example above the American continent andEurope).1.5RADIO
REGULATIONSRadio regulations are necessary to ensure an efcient and
economical use of the radio-frequencyspectrum by all communications
systems, both terrestrial and satellite. While so doing,
thesovereign right of each state to regulate its telecommunication
must be preserved. It is the roleof the International
Telecommunication Union (ITU) to promote, coordinate and
harmonisethe efforts of its members to full these possibly
conicting objectives.1.5.1 The ITU organisationThe International
Telecommunication Union (ITU), a United Nations organ, operates
under aconvention adopted by its member administrations. The ITU
publishes the RadiocommunicationRegulations (RR), which are
reviewed by the delegates from ITU member administrations
atperiodic World/Regional Radio Conferences (WRC/RRC).From 1947 to
1993 the technical and operational matters were administrated by
two committees:the CCIR (Comit Consultatif International des
Radiocommunications) and the CCITT (Comitee 37. Radio Regulations
13Consultatif International Tlgraphique et Tlphonique). The
International Frequency Registra- eeeetion Board (IFRB) was
responsible for the examination of frequency-use documentation
submittedto the ITU by its member administrations, in compliance
with the Radiocommunication Regula-tions, and for maintaining the
Master International Frequency Register (MIFR). Since 1994 the ITU
has been reorganised into three sectors: The Radiocommunications
Sector (ITU-R) deals with all regulatory and technical matters
thatwere previously handled respectively by the IFRB and the CCIR.
The Telecommunication Standardisation Sector (ITU-T) continues the
work of the CCITT, andthose studies by the CCIR dealing with the
interconnection of radiocommunications systemswith public networks.
The Development Sector (ITU-D) acts as a forum and an advisory
structure for the harmoniousdevelopment of communications in the
world.The abundant and useful technical literature previously
published in the form of reports andrecommendations by the CCIR and
the CCITT have now been reorganised in the form of ITU-R andITU-T
series recommendations. 1.5.2 Space radiocommunications servicesThe
Radiocommunication Regulations refer to the following space
radiocommunicationsservices, dened as transmission or reception of
radio waves for specic telecommunicationsapplications: Fixed
Satellite Service (FSS); Mobile Satellite Service (MSS);
Broadcasting Satellite Service (BSS); Earth Exploration Satellite
Service (EES); Space Research Service (SRS); Space Operation
Service (SOS); Radiodetermination Satellite Service (RSS);
Inter-Satellite Service (ISS); Amateur Satellite Service (ASS).
1.5.3 Frequency allocationFrequency bands are allocated to the
above radiocommunications services to allow compatibleuse. The
allocated bands can be either exclusive for a given service, or
shared among severalservices. Allocations refer to the following
division of the world into three regions: region 1: Europe, Africa,
the Middle East, the former USSR; region 2: the Americas; region 3:
Asia Pacic, except the Middle East and the former USSR.For example,
the xed satellite service makes use of the following bands: Around
6 GHz for the uplink and around 4 GHz for the downlink (systems
described as6/4 GHz or C band). These bands are occupied by the
oldest systems (such as INTELSAT,American domestic systems etc.)
and tend to be saturated. 38. 14 Introduction Around 8 GHz for the
uplink and around 7 GHz for the downlink (systems described as8/7
GHz or X band). These bands are reserved, by agreement between
administrations, forgovernment use. Around 14 GHz for the uplink
and around 12 GHz for the downlink (systems described as14/12 GHz
or Ku band). This corresponds to current operational developments
(such asEUTELSAT, etc.). Around 30 GHz for the uplink and around 20
GHz for the downlink (systems described as30/20 GHz or Ka band).
These bands are raising interest due to large available bandwidth
andlittle interference due to present rather limited use.The bands
above 30 GHz will be used eventually in accordance with developing
requirementsand technology. Table 1.3 summarises the above
discussion.The mobile satellite service makes use of the following
bands: VHF (very high frequency, 137138 MHz downlink and 148150 MHz
uplink) and UHF (ultrahigh frequency, 400401 MHz downlink and
454460 MHz uplink). These bands are for non-geostationary systems
only. About 1.6 GHz for uplinks and 1.5 GHz for downlinks, mostly
used by geostationary systemssuch as INMARSAT; and 16101626.5 MHz
for the uplink of non-geostationary systems such asGLOBALSTAR.
About 2.2 GHz for downlinks and 2 GHz for uplinks for the satellite
component of IMT2000(International Mobile Telecommunications).
About 2.6 GHz for uplinks and 2.5 GHz for downlinks. Frequency
bands have also been allocated at higher frequencies such as Ka
band.The broadcasting satellite service makes use of downlinks at
about 12 GHz. The uplink is operatedin the FSS bands and is called
a feeder link. Table 1.3 summarises the main frequency allocation
andindicates the correspondence with some usual terminology. Table
1.3Frequency allocations Typical frequency bandsRadiocommunications
servicefor uplink/downlinkUsual terminologyFixed satellite service
(FSS)6/4 GHzC band 8/7 GHzX band 14/1211 GHz Ku band 30/20 GHzKa
band 50/40 GHzV bandMobile satellite service (MSS) 1.6/1.5 GHzL
band 30/20 GHzKa bandBroadcasting satellite service (BSS) 2/2.2
GHzS band 12 GHz Ku band 2.6/2.5 GHzS band 1.6 TECHNOLOGY TRENDSThe
start of commercial satellite telecommunications can be traced back
to the commissioningof INTELSAT I (Early Bird) in 1965. Until the
beginning of the 1970s, the services provided weretelephone and
television (TV) signal transmission between continents. The
satellite was designedto complement the submarine cable and played
essentially the role of a telephone trunk connection. 39.
Services15The goal of increased capacity has led rapidly to the
institution of multibeam satellites and there-use of frequencies
rst by orthogonal polarisation and subseqently by angular
separation(see Chapter 5). Communication techniques (see Chapter 4)
have changed from analogue to digital.The second-generation DVB-S2,
although backward compatible with DVB-S, has made use of themany
novel technologies developed in recent years, including modulation
techniques of 8PSK,16 and 32 APSK in addition to QPSK; efcient
forward error correction (FEC) with new low-densityparity check
(LDPC) codes; adaptive coding and modulations (ACM); and
performance close to theShannon limit. This makes DVB-S2 30% more
efcient than DVB-S. DVB-RCS can provide up to20 Mbit/s forward link
to user terminal and 5 Mbit/s return link from user terminal, which
iscomparable to ADSL technology. Multiple access to the satellite
(see Chapter 6) was resolved byfrequency division multiple access
(FDMA). The increasing demand for a large number of lowcapacity
links, for example for national requirements or for communication
with ships, led in 1980to the introduction of demand assignment
(see Chapter 6) rst using FDMA with single channelper
carrier/frequency modulation (SCPC/FM) or phase shift keying (PSK)
and subsequentlyusing time division multiple access/phase shift
keying (TDMA/PSK) in order to prot from theexibility of digital
techniques (see Chapter 4). Simultaneously, the progress of antenna
technology(see Chapter 9) enabled the beams to conform to the
coverage of the service area; in this way theperformance of the
link was improved while reducing the interference between systems.
Multibeam satellites emerged, with interconnection between beams
achieved by transponderhopping or on-board switching using SSTDMA
(satellite-switched time division multiple access).Scanning or
hopping beams have been implemented in connection with on-board
processing onsome experimental satellites, such as Advanced
Communications Technology Satellite (ACTS). Multiple beam antennas
of today may produce hundreds of beams. Indeed, this brings a
twofoldadvantage: the link budget is improved to small user
terminals thanks to the high satellite antennagain obtained with
very narrow beams; and the capacity is increased by reusing the
frequency bandallocated to the system many times. Flexible
interconnectivity between beams is required more than ever and may
be achieved atdifferent network layers by transparent or
regenerative on-board processing. Regenerativepayloads take
advantage of the availability of baseband signals thanks to carrier
demodulation.This is discussed in Chapters 7 and 9. Intersatellite
links were developed for civilian applicationsin the framework of
multisatellite constellations, such as IRIDIUM for mobile
applications, andeventually will develop for geostationary
satellites (Chapters 5 and 7). The use of higherfrequencies (Ka
band at 30/20 GHz) enables the emergence of broadband services,
thanks to thelarge amount of bandwidth currently available, in
spite of the propagation problems caused by raineffects (Chapter
5). 1.7SERVICESInitially designed as trunks which duplicate
long-distance terrestrial links, satellite links haverapidly
conquered specic markets. A satellite telecommunication system has
three propertieswhich are not, or only to a lesser extent, found in
terrestrial networks; these are: the possibility of broadcasting; a
wide bandwidth; rapid set-up and ease of reconguration.The
preceding section describes the state of technical development and
shows the development ofthe ground segment in respect of a
reduction in the size of stations and a decreasing station
cost.Initially a satellite system contained a small number of earth
stations (several stations per countryequipped with antennas of 15
to 30 m diameter collecting the trafc from an extensive areaby
means of a ground network). Subsequently, the number of earth
stations has increased with 40. 16 Introductiona reduction in size
(antennas of 1 to 4 m) and a greater geographical dispersion. The
stations havebecome closer to the user, possibly being
transportable or mobile. The potential of the servicesoffered by
satellite telecommunications has thus diversied. Trunking telephony
and television programme exchange; this is a continuation of the
originalservice. The trafc concerned is part of a countrys
international trafc. It is collected anddistributed by the ground
network on a scale appropriate to the country concerned.
Examplesare INTELSAT and EUTELSAT (TDMA network); the earth
stations are equipped with 15 to30 m diameter antennas.
Multiservice systems; telephone and data for user groups who are
geographically dispersed.Each group shares an earth station and
accesses it through a ground network whose extent islimited to one
district of a town or an industrial area. Examples are TELECOM 2,
EUTELSAT,SMS, and INTELSAT (IBS network); the earth stations are
equipped with antennas of 3 to 10 mdiameter. Very small aperture
terminal (VSAT) systems; low capacity data transmission (uni- or
bi-directional), television or digital sound programme broadcasting
[MAR-95]. Most often, the useris directly connected to the station.
VSATs are equipped with antennas of 0.61.2 m in diameter.The
introduction of Ka band will allow even smaller antennas (USAT,
Ultra Small ApertureTerminals) to provide even larger capacity for
data transmission, allowing multimedia inter-activity,
data-intensive business applications, residential and commercial
Internet connections,two-way videoconferencing, distance learning
and telemedecine. Digital audio, video and data broadcasting; the
emergence of standards for compression, such asthe MPEG (Motion
Picture Expert Group) standard for video, has triggered the
implementationof digital services to small earth stations installed
at the users premises with antennas of theorder of a few tens of
centimetres. For television, such services using the DVB-S
standardare progressively replacing the former broadcasting of
analogue programmes. Examples ofsatellite systems broadcasting
digital television are ASTRA, HOT BIRD, DirectTV, ASIASAT,etc. For
sound, several systems incorporating on-board processing have been
launched in sucha way as to allow FDMA access by several
broadcasters on the uplink and time divisionmultiplexing (TDM) on a
single downlink carrier of the sound programmes. It avoids
thedelivery of the programmes to a single feeder earth station, and
allows operation of the satellitepayload at full power; This
approach combines exibility and efcient use of the
satellite.Examples of such satellite systems are Worldspace,
Sirius/XM-Radio. The ability of the userterminal to process digital
data paves the way for satellite distribution of les on
demandthrough the Internet, with a terrestrial request channel or
even a satellite-based channel. Thisanticipates the broadband
multimedia satellite services. Mobile and personal communications;
despite the proliferation in cellular and terrestrialpersonal
communication services around the world, there will still be vast
geographic areasnot covered by any wireless terrestrial
communications. These areas are open elds for mobileand personal
satellite communications, and they are key markets for the
operators of geosta-tionary satellites, such as INMARSAT, and of
non-geostationary satellite constellations, such asIRIDIUM and
GLOBALSTAR. The next step bridging the gaps between xed, mobile
andbroadcasting services concerns satellite multimedia broadcast to
xed and mobile users,known as satellite digital mobile broadcasting
(SDMB). Mobile TV services are available onterrestrial 3G networks
in a point-to-point mode, not optimised to deliver the same content
tomany users at the same time. Smart overlay broadcast networks
based on hybrid satelliteterrestrial mobile systems will efciently
provide end users with a full range of entertainmentservices with
interactivity [WER-07]. A dedicated standard (DVB-SH) has been
developed forthese mobile broadcast applications. Multimedia
services; these services aggregate different media, such as text,
data, audio,graphics, xed or slow-scan pictures and video, in a
common digital format, so as to offerexcess potential for online
services, teleworking, distance learning, interactive television,
41. The Way Forward17telemedicine, etc. Interactivity is therefore
an embedded feature. They require an increasedbandwidth compared to
conventional services such as telephony. This has triggered the
conceptof an information superhighway. Satellites complement
terrestrial, high-capacity bre, cable-based networks with the
following characteristics: use of Ka band, multibeam
antennas,wideband transponders (typically 125 MHz), on-board
processing and switching, a large rangeof service rates (from 16
kbit/s to 10 Mbit/s) and quasi-error-free transmission (typically
1010bit error rate). 1.8THE WAY FORWARDIn the last 30 years, the
satellite telecommunications landscape has changed
signicantly.Advances in satellite technology have enabled satellite
telecommunications providers to expandservice offerings. The mix of
satellite telecommunications is continuously evolving.
Point-to-pointtrunking for analogue voice and television was the
sole service initially provided by satellites30 years ago. In
addition, telecommunications satellites today are providing digital
audio andvideo broadcasting, mobile communications, on-demand
narrowband data services and broad-band multimedia and Internet
services. The mix of service offerings will continue to
changesignicantly in the future. Satellite services can be
characterised as either satellite relay applications or end-user
applica-tions (xed or mobile). For satellite relay applications, a
content provider or carrier will lease capacityfrom a satellite
operator, or will use its own satellite system to transmit content
to and fromterrestrial ground stations where the content is routed
to the end user. Relay applicationsaccounted for around $10 billion
in 2000. End-user satellite applications provide information
directlyto individual customers via consumer devices such as small
antenna (less than earth station)and hand-held satellite phones.
End-user applications accounted for about $25 billion in 2000.It
was reported b
