Satellite Communications' Technological Evolution
Javier de la Plaza Ortega
R&D International Telecom Programmes Consultant, Madrid 28002, Spain
Abstract - From their beginning, the Satellites have played a
Many of the Telecom activities have been supported by
fundamental role all over the world for the scientific,
national or international Agencies, as NASA , NASDA
technological, economic and social development, in
particular the communications systems have constituted an
essential part of the Space Supersystem, for the support of
platform telemetry, telecommand and ranging facilities, as
for the big variety of applications, which are onboarded, for
many different missions.
The satellite broacasting, in particular, has become very
and ESA, with a very important role for the technological
research and the strategic technological development.
The size, architecture and related performances, either for
rockets, satellite platforms and telecom payloads, have
evolved very quickly, mainly motivated by the parallel
evolution of the terrestrial telecom services.
important along many years, for various satellite application
II. TRADITIONAL TELECOM SATELLITES
areas:
- Scientific satellites, for the distribution of a variety of
scientific data, to the earth laboratories and research centres
- Telecommunication satellites, for supporting audio, video,
data and multimedia user services
- Observation satellites, for the transmission of
environmental data to world research centres and
institutions
The traditional satellite communication systems have had
a big development in the last four decades on the basis of
Repeater architectures, made of on board payloads
embarked in geostationary satellites, their application
field has been mainly distribution services, long distance
- Navigation satellites, for global distribution of navigation
trunks for telephone networks, voice and data services in
signals and data to users, in order to provide positioning,
VSAT networks, and limited mobile services in the two
location and timing services
last decades.
Although there is a variety of satellite broadcasting
emergence of the digital technologies by the 80's, with the
applications, the most popular for the citizens have been
telecommunications services, therefore the present
contribution will be focused on this topic, mainly on the
technological evolution of the satellite communications in the
last two decades.
Index terms: Satellite, onboard processing, network,
integration, multimedia, IBIS Sytem.
1. INTRODUCTION
Initially the Telecommunication satellites were oriented to
the intercontinental communications, mainly for telephone
and television services, due to the complex infrastructure
and the high cost of the transatlantic cable solution.
The fundamental vision for starting the satellite
telecommunications era was published in 1945 by Arthur
C. Clarke, the approach consisted in the positioning of a
Geostationary Satellite in a 36.000 km orbit, about 20
years latter was launched the first commercial satellite
named Early Bird, able to support a few telephone and
television analogue channels. In the beginning, only a few
industries and operator companies were involved in such a
business, being pioneer the US space industries and the
Intelsat Operator. Latter on, other industries in Europe
were created, as well as Telecom operators as Eutelsat,
and Hispasat in Spain by the end of 80's, today there are a
lot of space industries and operators in many countries
worldwide, with thousends of commercial Television
digital channels, Internet and Mobile connections, within
a global coverage.
The Euroconsult Satellite Communications &
Broadacasting Market Survey - Worldwide Prospects to
2010, references the main Space Industries and Telecom
Operators.
A first driver for satellite systems upgrading was the
research and building of new satellite platforms, new
frequency bands, payload features and network
architectures.
The high scale implementation of the Optical Fibre and
the Cable networks, joined to the liberalization of the
space sector in many countries, have made that the
applications as well as the transparent satellite
communication architectures would evolve more
significantly in the following years, for supporting new
distribution services as for interactive voice, data, video
services, both for fixed and mobile communications.
III. SATELLITE SERVICES EVOLUTION
Telecommunications is the most mature of Space
applications, 60% of the European industry turnover is
derived from producing or launching telecommunications
satellites, 90% of the satellites launched by Ariane are
Telecommunication satellites, we could say that without
Telecommunications satellites the space industry would
not be sustainable
The main classes of services supported by means of
satellite technologies have evolved in the past in the
following order:
1st. Broadcast services
Satellite TV has dramatically affected the way society
perceives itself, news are delivered anywhere, any local
programme can be broadcasted almost everywhere.
All technical innovation goes first by satellite, that was
the case of Digital TV, only changing the signal a full
country or continent can receive the new service, 60-70%
of all satellite capacity is dedicated to Television, either
Broadcasting, Distribution or Transport, it reaches your
home, your cable or your UHF repeater via satellite.
978-1-4244-7451-61101$26.00 ©2010 IEEE
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Today there are more than 20000 Digital TV channels in
compliant Reference Model has been the IBIS System
Orbit, most of these are SDTV, Satellites are becoming
(Integrated Broadcast-Interactive System), that was fully
the primary means to broadcast HDTV.
supported by the European Space Agency and the
2nd. Fixed Services
European Commission R&D Programmes.
Historically Fixed services brought the planet together,
Actually there are four IBIS Satellite Communications
twenty years ago two of three intercontinental telephone
Systems in the world, Amerhis 1 and 2 in operation within
calls were made by satellite, the main applications of FSS
Hispasat Amazonas Satellites and REDSAT and
have been:Trunking, VSATS and TV contribution, today
OVERHORIZON, in manufacturing.
2600 Transponders are dedicated to these services.
Such new requirements and performances have been
3rd. Broadband services
achieved by means of multibeam configuration and on
Several Broadband systems have been developed and are
board processing tecniques, allowing direct user end to
in progress, from 2 Gbits up to 70 Gbits capacities, Ka
end communications, with more selectivity in space and
Band Multispot beam allows to increase the satellite
time, transmitting to each user the desired information,
capacity and reduce the price of the space segment by a
instead of performing a global broadcast radiation, with
factor of 50.
the consequent saving of power and operative costs.
4th. Mobile interactive services
The next generation of Satellite Communication Systems
MSS have made possible communications on the oceans,
is providing new services to the users and new network
on the air and on the deserts, the system architecture is far
applications, a big operation and management flexibility,
from being consolidated, traditionally Inmarsat has
and a cost reduction with respect to the traditional
leadered this sector, the last generation, on board
systems.
processing based, as Iridium constellation failed to
success.
The differential elements between a Transparent
5th. Mobile broadcasting services
architecture and an On board Processing architecture, are
Broadcasting to mobiles has emerged as a new service in
as follows:
the present century, system architecture is based on high
1) Transparent architecture:
power satellites in the S/L band and DVB-SH standard.
Reception antenna, low noise amplifier, transmit
frequency converter, frequency demultiplexer, individual
IV. ARCHITECTURAL EVOLUTION
channel amplifier, transmit power amplifier, transmit
frequency multiplexer and transmit antenna.
The general utilization of the Optical fibre and the
2) On board processing architecture:
dramatic evolution of the terrestrial telecom services
Intermediate frequency converter, digital frequecy
obliged the satellite telecom sector to the development of
demultiplexer, digital multicarrier demodulator, baseband
very advanced digital satellite payloads, and related
processor, digital modulator and transmit frequency
network architectures, with the appearance by the 90's, of
conversion.
a new generation of satellite communications based on On
Board Processing and Switching. After many years of
V. ON BOARD MULTIPLEXING TECHNOLOGIES
research and development activities, new payloads for On
Board Multiplexing as Skyplex, and for Switching and
The first standard multiplexing system using on board
Routing as, Thuraya, IBIS-Amerhis and Spaceway GEO
processing techniques has been based on the MPEG2 and
Satellite Systems became into operation, following a huge
DVB standards, it was the Skyplex System, with the
technological and economical effort.
objective of providing direct access for digital Tv
Also some LEO and MEO satellite systems were
servcies, over widespread areas, without the need of the
developed and put into operation, but in particular the
terrestrial infrastructures, in Fig. 1 is shown the
LEO architecture was very unsuccessful, it was the case
differential network architecture. A big variety of digital
of the commercial Iridium LEO System, that was a very
services can be supported by means of an universal
ambitious but also a very unrealistic approach, and also
standard as it is the DVB . - The on board processing
the cancelled Teledesic System , the MEO architecture
functionality consists on the digital multiplexing of the up
application was not very significant.
link DVB signals onto an standard DVB downlink.
All of the different Research and Development Projects
were presented in many Satellite World Communications
The multiplexing solution, shown in Fig.1, allows to the
Conferences ( AIAA, Ka Band, ESA..) along more than
various operators the transmission from any location, with
ten years, with many different technical and economical
a big flexibility in position as well as in the speed of the
analysis, to support their technological feasibility and
transmitted information, it has been the first phase for the
economical justification, most of them were proprietary
introduction of interactive services, which requires a
technological solutions, it was the main reason to fail in
bidirectional communication between the user and the
the operational target.
service provider, as an essential step for the
The GEO approach was the most supported, along the
implementation of digital integrated services by satellite.
various world Conferences, under two strategic lines : the
Proprietary System architecture strategy, followed by
VI. ON BOARD SWITCHING TECNOLOGIES
Hughes as Spaceway, and the Standard System
architecture, created and fully leadered by Alcatel
The advanced functionalities and performances required
Espacio, today Thales-Alenia Space. The Standard
by the new Telecommunication Satellite Services have
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been achieved by means of Multibeam Architectures and
VII. MULTIMEDIA INTEGRATED SYSTEMS
On Board Processing and Switching (OBP), with low
level of information bandwidth management and full
The development of multimedia interactive systems with on board
resources flexibility, in such way that it will be possible to
switching, has had two fundamental problems : a first one due to its
comply any distribution, routing and advanced telecom
technological complexity, with the associated research and
service requirement, for the selective coverage of big
development challenges and the related high investment costs, and a
extension regions.
second one due to be based in proprietary solutions, as a major
reason to make so difficult to reach the marketing target for a
Within the ATM cell switching development lines, or
commercial success.
similar, have been developed, along the 94 to 2004
The first system solution that has been developed, for an Standard
decade, a set of initiatives in Europe, United States and
Integrated System, already in operational service, within this new
Japan for the implementation of different kind of systems,
generation network, is the one developed in the IBIS Project of the
with satellite on board processing, to find a global
European Commission R&D programme, where it was performed
solution for the present and future multimedia service
the definition and specification of an integrated system for the
requirements.
interactive Internet Multimedia Network, followed by the design and
In this sense, the European Space Agency ( ESA)
development of a ground system model, representing the space
initiated, by the beginning of the 90 's, a programme of
operational system, today in service.
advanced GEO satellite communications, such
programme was initially based in Ku band for supporting
of ISDN switching services, then evolved to Ka band,
VIII. THE IBIS SYSTEM TECHNOLOGY
packet services, ATM cells and to MPEG2 packets under
the ETSI DVB Standard. Finally the IP/MPEG2 over
The IBIS is a Satellite Multimedia System, where the
DVB was considered as the most realistic and effective,
Broadcast Network part is integrated with the Interaction
both in the European Commission programmes as in the
Network part, for supporting Interactive Tv, Internet and
ESA Telecom programme, and it has become the
Multimedia services. The up link is based on the DVB­
Reference Model for the new standard operational
RCS standard and the down link is compliant with the
systems, actually in service.
DVB-S standard. The information and data is transported
The IBIS System, has determined the Reference Model
according to the MPEG-2 and IP Standards, and the
for this New Generation of Satellite Communications, and
system is implemented by following the ETSI Reference
it has been the first integrated Internet Multimedia System
Model for Interactive Systems.
in compliance with the ETSI Standards. The specification,
design and development of the first ground operational
Such an advanced Interaction System is able to support a
model was developed within the R&D Workframe
big set of the emerging Commercial Applications, for a
Programme of the European Commission.
great variety of Interactive Digital TV, Internet and
The Amerhis-l system has been the first operational
Multimedia services, within an interaction network, in
system embarked in satellite, within the Amazonas-l of
compliance with the major flexibility and interoperability
the Hispasat Satellite Operator. It is an space
requirements. The referred integrated Return Link is
configuration of the IBIS reference model, and, based on
defined for an on board regenerative architecture, in a
its multibeam architecture, is giving service to South
satellite multi-spot configuration environment, by using
America, Brasil (specific), North America and Europe.
the most advanced on board processing techniques.
Spain, by means of Alcatel Espacio, today Thales-Alenia
Space, played a leadership role along the ESA and
A full set of advanced digital services is made available
European Commission R&D Programmes, I had
directly to the end users by means of a satellite
personally the honour for the direction and coordination
infrastructure able of supporting point to point, point to
of the whole Projects of the OBP R&D Programmes,
multi-point, multicast and broadcast configurations.
being the creator of the IBIS System.
The System consists of the following operational units:
Broadcast- Interactive Payload (in Satellite), User Traffic
The advanced Satellite Communications Networks will be a
Stations (UTS) and User Terminals, Service Provider
very important component, in general, for the Telecom Next
Stations (SPS) and SP Terminals, Content Provider
Generation Network ( NGN), initiated by 2000, and in many
Stations (CPS) y CP Terminals, Gateway Stations (GWS)
cases, it will be the only solution until the terrestrial network
has the required level of development. In particular, the future
and GW Terminals, Network Control Centre and
Multimedia Service Centre, in Fig.2 is shown the
networks with satellite processing and switching, will allow
architecture of this New Generation Internet Multimedia
very quickly, the ideal architecture for the integration and
Network.
management of end to end multimedia services.
A.
Space Segment
In Fig-2 it is shown an overall diagram of the OBP Internet
Multimedia Network architecture, based on the IBIS System,
The IBIS Broadcast Interactive Payload is the core of the
as the first Standard On Board Satellite Processing and
system,
Switching approach in the world.
functionalities :
•
•
and
it
performs
the
following
Frequency Demultiplexing
Signal Demodulation
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netwok
On Board Decoding
basic performances of this new generation system are as follows:
•
On Board Switching /Routing
1. Regenerative Multispot architecture, in a single hop
•
Down Link Multiplexing
configuration
•
Down Link Modulation
•
2. Up Link
The key part of the Payload is the Base-Band Processor
( BBP ), which inputs are the IF signals coming from each
input receiver, according to the applications, a set of
3. Direct end to end connection of Standard User
Terminals
multipoint connectivity
configuration.
A MUX module is in charge of multiplexing outputs from
several data sources,supporting multicast as well, and to
build the DVB-S compliant packets for the downlink.
The output of each MUX is analogue converted as final
stage in the processor, following this stage the modulator
and RF step are equipped to send the stream on the
5. Symmetrical and asymmetrical traffic handling, with
high bandwidth management performances
6. National, regional and global coverage, with excellent
link budget
7. Separated Transport Network and Service domains
8. Supporting of different services within an integrated
and standard architecture
convenient downlink.
The interconnection between different spots, related to the
corresponding modulators and providing multicast
9. System and network architecture oriented to
Multimedia services, with easy evolution to new service
requirements
performances, is carried out by means of the Multicast
10. Public and private network applications
Switch-Mux.
11. Terrestrial network emulation by single Node direct
end to end connectivity
B. Ground Segment
12. Interworking with digital terrestrial networks, either
4 types of Ground Stations Units are provided :
User Station Unit: This kind of unit is able of receiving
the downlink multiplex (DVB-S) and uplinking via an
channel
Down Link decoupling, with half
4. Selective distribution of Information, in multicast and
BBPs can be equipped for a multibeam network
Interaction
�
communication delay
(DVB-RCS).
These
units
are
typically used for accessing multimedia traffic, either
directly or via a home or corporate network.
Within this classification, different types of users can be
distinguished : consumer, prosumer and corporate users,
the prosumer and corporate ones are considered as more
promissing in the short term.
Service/Content Provider Unit: These units will be
capable of receiving the downlink multiplex and
uplinking via a broadcast-interaction channel. They are
used for Interactive services as to contribute broadcast and
multicast channels to the Satellite System.
Gateway Station Unit : This unit provides the adaptation
between the satellite environment and the terrestrial
network environmet, it allows to interface either
trerrestrial nodes or terrestrial head- ends.
Network Control Center: This is a very complex unit in
charge of performing the whole Network synchronisation,
control and management. It is able to receive the DVB-S
down link and it transmits by means of the DVB-RCS up
link.
fixed or mobile
13. Performance quality similar to terrestrial networks
14. Scalable dimensioning up to tens of gigabits per
second
15. Bearer services from 64 kbps up to 4 Mbps as baseline
16. Audio, video and data distribution, contribution (i.e.
news gathering) and caching services
17. Advanced audio, video and data Interactive services:
Digital Tv, Internet mail Internet web, ..
18. Multimedia integrated services
19. Selected set of mobile services, with portable or
mechanical transport terminals
20. High functional flexibility of the on board Payload
21. Integration of all existing satellite telecom services, in
transparent, multiplexed and switched modes
22. Easy end to end service creation
IX. CONCLUSIONS
The satellite tecnologies have allowed many different
kind of applications, within the space environment, as
Scientific, Observation, Navigation and
Telecommunications applications.
In particular, Satelite Comunications have played in the
The present Satellite System approach provides a very
cost effective solution for the integration of the Broadcast
and Interactive service and application requirements,
which are imposed by the advanced Multimedia
Networks, allowing a direct end to end communication
between Users and Service / Content Providers, with
optimised link access, very low data granularity and
excelent flexibility and reconfigurability features.
C. IBIS System Performances
Due to the variety of potential services and the big exten
sion of the geographic area that can be covered by the
IBIS System, the market requirements shall be defmed
last four decades a fundamental role in providing a big
variety of telecommunication services to the citizens,
contributing to the quick social and econimical
development of most world countries.
The communication tecnologies are evolving very
significantly during the last two decades, from the
traditional Transparent architectures to the Multibeam and
On Board Processing (OBP)architectures, by means of
regenerative multi spot satellites, such evolution has been
progressing in parallel competion with the terrestial
networks, allowing today a very advanced set of
Telecommunication services and applications, within the
Internet Multimedia age.
for each specific case, in order to specify the adequate
system requirements and performances. However, the
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3. ldela Plaza! R. Rey, " First Standard Broadcast­
REFERENCES
Interactive Model",
Ka Band Utilization World
Conference 2002
4. S. Chacon et aI.,"Networking over the IBIS System",
1. C. Elia" Skyplex System" ESA 1998
2. 1 de la Plaza, "Integrated Broadcast-Interactive System
Wireless and Mobile Summit 2002
-IBIS"- Ka
5. J. de la Plaza, "New Generation of Satellite
Band Utilization World Conference 2001
Communications" BIT COlT Magazine / Nr 170 Agosto
2008
TERREST.
AND
DVB
CENTRAL
SATELLITE
SATELLITE
STATION
NETWORK
MMEDIA
SERVICE
PROVIDER
MM
HEADEND
RETURN CHANNEL BY
PUBLIC SWITCHED NETWORK
DEDICATED AND INTERNET
Fig.l - Satel1ite On Board Multiplexing Network
Differential architecture
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-
---
--
---
.........
-
GW
Term inal
/
,
,
* INTERNET NETWO
* ATM NETWORK
* MM HEADEND
ACCESS
/
�
.......
......
......
---
---
....".,
Fig.2- OBP Internet Multimedia Network
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