The Future of Broadband Satellite Communications
Professor Joseph N. Pelton, Director, Space and
Advanced Communications Research Institute (SACRI)
George Washington University
and
Exec. Director, The Arthur C. Clarke Institute of
Telecommunications and Information
The Future of Broadband Satellite Communications
By Dr. Joseph N. Pelton
Executive Director, Arthur C. Clarke Institute
Director, Space & Advanced Communications
Research Institute,
George Washington University
1.0 Introduction
If humankind can avoid highly destructive uses of technology such as nuclear and chemical and biological weapons, the 21st century could represent a golden age of human scientific progress in terms of speed and range of innovation. The Internet within two decades will allow access to a thousand times more information than it does today and at much higher speeds. Broadband access to informational and educational systems at incredible speeds should be increasingly affordable and accessible around the globe. Today some 2 billion people, a third of the world's population, have limited or no access to basic education, health care, electrical power, potable water, communications or modern electronic forms of information. By the next century one must hope that everyone on our planet has fulfilled these fundamental needs.
An important part of the ongoing economic, technological and social revolution that has come with the Internet Age are the opportunities that are provided by the newest forms of satellite communications technology and applications. Although fiber optic networks are a key part of the new information infrastructure there are limits to what terrestrial cable systems can accomplish. In short fiber, terrestrial wireless and satellite systems will work in tandem to provide key needs for the future.
There are currently a myriad of key new developments occurring in the satellite field in Japan, the United States, Europe and other parts of the developed and developing world. These rapid technological advances, however, are accompanied by challenging issues related to globalism and international cooperation, techno-terrorism, new demanding types of broadband applications, trade policy concerns, frequency allocations, intellectual property, and regulatory and institutional reform. Although this chapter focuses primarily on technology it is important to note that policy, regulatory and economic issues will have a key role in making satellite services available on a broad global basis to those who need these capabilities most.
1.1 Historical Background and context
Many centuries of scientific and engineering
development led to the development of communications satellite technologies and
systems. Key milestones along the
way include:
Archetus
of Tarentum developed the idea of steam-based jet propulsion in the 3rd
century B.C.
Chinese inventors developed prototype rocketry in the
Middle Ages.
Sir
Isaac Newton discovered the universal laws of gravitation and computed escape
velocities during the Late Renaissance.
Samuel
Morse and Alexander Graham Bell developed the electric telegraph and the
telephone in the middle of the 19th century
James
Clerk Maxwell developed in the second half of the 19th century the
basic theoretical formulas that explain electro-magnetic behavior.
Marconi
developed the basic concepts of electronic radio communications at the turn of
the 20th century.
Tsiolokovsky,
Ley, Goddard and Von Braun developed modern rocketry concepts during the first
part of the 20th century.
Arthur
C. Clarke developed the detailed telecommunications and orbital concepts for a
geosynchronous global satellite system in 1945.
Shockley,
Bardeen et al developed the transistor in the late 1940s. This enabled the practical development
of lightweight and reliable computers and telecommunications components that
allowed the design and launch of unmanned communications satellites.
Finally
in the late 1950s the age of manmade satellites began. Sputnik, the world's first artificial satellite, was launched by the Soviet Union in October 1957. This was followed in rapid succession
by the first communications satellites (Score, 1958; Courier 1B, 1960, Telstar,
1962, and Syncom 1B (the first geosynchronous satellite in 1963).
From
the very outset, satellite telecommunications made a direct impact on the
social and economic development of the world. The deployment of Early Bird (or INTELSAT 1) in geosynchronous orbit in April 1965 immediately doubled the world's international telephone capabilities by adding 240 voice circuits across the Atlantic Ocean. For the first time in human
history networks could also routinely send live broadcasts of television across
an ocean. The initial pictures
were only fuzzy black and white images, but the age of global satellite
television was ushered in by images of Dr. Michael DeBekey performing open
heart surgery in Houston, Texas while surgeons observed via satellite
television in Geneva, Switzerland.
Other firsts were "live" trans-Atlantic coverage of the Le Mans auto race in France and the various live exchanges between Heads of State across the Atlantic in 1965 and across the Pacific on INTELSAT II satellites in 1967. Within a blink of the eye, the phrase "Live Via Satellite" entered the modern lexicon.
A
spurt in international communications followed in the 1970s. This was fueled by increasingly
powerful and higher capacity satellites and then later by fiber optic submarine
cables. International
communications in two decades increased in capacity by more than 100 times. This growth in global communication, at
least in part, led to a leap in international trade‹at all levels (i.e.,
commodities, products and goods, and even services). At the domestic level satellites proved to be more important
as an entertainment media. In many
countries, satellite communications networks particularly served to increase
national and regional television news coverage and also led to the rapid growth
of Cable television programming.
Satellites have also been used for nearly 40 years now for both
education and tele-health services.
As noted above, the very first satellite television transmissions was to
support medical training and new surgical techniques. Educational broadcasts soon followed in the U.S., Canada,
Australia, Japan and Europe.
Today
the Chinese National Television University that began with experiments under
the Project Share experiments of Intelsat
in 1985, now reaches millions of students and teachers everywhere in the vast
China subcontinent. In the second
most populous country, India, the Insat system reaches an estimated million
students with its tele-education broadcasts. The reliance of satellites for educational purposes using
conventional analog technology is now extremely widespread. Perhaps a majority of all the countries
of the world and certainly the largest countries in terms of population all use
analog (and in some cases digital satellite television broadcasts) to support
distance education. On a daily basis
over 20 million students are today relying on satellite tele-education for at
least a part of their education.
Despite
these gains many problems remain.
Some countries have to pay extremely high tariffs for simple 56
kilobit/second data and voice links when broadband services at 1.5
Megabits/second or 2.0 Megabits/second are available in more economically
developed countries at almost the same price. In short, as the Global University System and others have
found the largest barrier to cost effective satellite communications are
regulatory systems and tariff structures and not the availability of new
satellite technology. Nevertheless the continuing surge forward in satellite
technology continues to put pressure on all concerned to low the tariffs for
satellite services, particularly for health and education. The initiatives by the World Bank
(IBRD) in this regard now appear on the verge of paying off with wide spread
availability of satellite capacity for social services.
1.2 Major
Trends in Satellite Systems
Many observers of telecommunications development have seen the highly competitive side of the parallel development of satellite communications and fiber optic cable systems. In fact, the rapid development of both fiber and satellite technology would likely have been much slower without the competitive demand to deliver more and more capacity at lower and lower cost. Just as the computer industry has generally followed Moore's Law of a doubling of capacity every 18 months for the last quarter century, satellites and fiber have maintained this type of exponential growth in performance as well.
In 1965, prior to the launch of Early Bird, there were less than 300 international telephone circuits in operation and no transoceanic television broadcasting capability. Now there are over 1 million international satellite circuits in operation, and many millions of fiber optic circuits available. The number of full-time national, regional and international satellite television channels in operation on a global basis exceeds 12,000. What is particularly notable in this last statistic is that the first full-time international satellite television channel did not begin to operate until 1984. Most recently the evolution of digital television channels (and particularly MPEG 2 standards that allowed a video broadcast transmission at 6 megabits/second) have created a major spurt of growth in this arena.
Many other new applications and services have stimulated the continuing rapid growth of satellite communications throughout the 1990s. Some of the very most important of these new services and applications are:
INTERNET: The amount of Internet-related traffic on the INTELSAT system alone has grown from 7% of all traffic in 1998 to over 20% of all traffic today. Most of this Internet Protocol (IP) traffic is operating on via digital video broadcast systems that can provide digital down-linking to low cost 1 meter earth stations at speeds up to 70 Megabits/second. Major gains in IP based traffic have also been achieved on the Panamsat, Loral, SES Global, New Skies and Eutelsat systems. The desire for Internet access continues to grow and mature via satellites, terrestrial wireless and fiber optic networks. Advanced data, voice and multi-media services via the IP protocol will likely lead to the need for even more advanced, broader band satellite systems in the 21st century.
Virtual Private Corporate Networks and Intranet-based LANs: The rapid evolution of so-called Very Small Aperture Terminals (VSATs) and now micro-terminals or Ultra Small Aperture Terminals (USATs) have made satellites ideal for supporting integrated corporate voice, data, multi-media networking via these small customer premise terminals that allow corporate based Wide Area Networks (WANs) to interconnect together and also connect directly to the Internet. It is key to note that there is at least ten (if not twenty) times more information on dedicated Intranets than on the Internet itself.
Multi-media and Bandwidth on Demand: In today's global economy, world-wide enterprises operate on a 24 hour a day basis in scores of countries around the world. The flexibility of satellites to provide multiple connections and provide narrow band to broadband services on demand have contributed to their growth. Initially this traffic was essentially to support business, but today these networks are supporting medical and health care, governmental services, education and training and an ever widening range of applications.
Big Science: The space-based Earth Observation Satellite (EOS) System (also known as Mission to Planet Earth) will provide global remote sensing and earth observation data as never before possible. The next ten years of operation of the EOS system will produce an estimated 3,000 terabytes of information. This massive amount of information (equivalent to 1500 Libraries of Congress or thousands of time the amount of information on the Internet) is only one of the applications that support terabyte data systems. By 2020 there will even be research and science projects that deal with petabyte databases (i.e., at least 1,000,000,000,000,000 bytes of data.) Support for such "big science" projects will require huge amounts of satellite communications relay. Even if so-called "pre-processing of data" on-board the satellites can reduce the amount of total information to some degree, the demands on satellite communications by big science projects will be enormous. Today we have just a few projects of this size, like the Hubble Telescope and globally interconnected observatories or the Earth Observation System Data Information System (EOS-DIS) etc. Tomorrow there will dozens of such huge information and communications collection and processing projects.
Mobile Communications and Remote Access Requirements: The most surprising telecommunications development of the 1990s has been the insatiable demand for mobility and access to global networks anywhere on the planet. This has led to the extremely rapid development of analog and digital wireless telecommunications networks (now nearing 100 million mobile telephones) and now even the deployment of personal communications mobile satellite systems such as New Iridium, Globalstar, New ICO, ACeS, Thuraya-M2, etc. Terrestrial wireless and mobile systems have grown prodigiously on the basis of demand for mobile and remote access. As this demand becomes more mature and seeks broader band service this will fuel the demand for new higher frequency and higher throughput satellite systems with many of these operating in the new Ka, Q and V frequency bands. There can be no doubt as these broader band mobile satellite systems come into wider scale use that their applications for education and health will continue to increase.
Broadband Entertainment Services: The greatest strengths of satellite systems may well be in point-to-multi-point distribution systems, broadcasting networks and now in multi-media based multi-casting system. Satellites have been key to the growth of national cable television systems, and CD quality radio broadcasting. In the 21st century, multi-casting based applications such as software distribution networks, electronic libraries and catalog systems and even computer-based interactive and asymmetric electronic games will create a dizzying array of new applications.
All of these applications and many more will support the global growth of the communications satellite services industry from $25 billion as of 1998 to $75 billion a year by 2005. New 21st century applications will continue to explode. This growth will, however, likely be dominated by multi-casting, broadcasting, navigational and mobile services plus Internet and Intranet based services. These will include interactive and mobile security systems, intelligent building and campus operations, integrated mobile communications and navigation services, intelligent highways, dedicated business and research networks and, of course, tele-education and tele-health services.
In short, these innovations in satellite technology and new satellite applications open the door not only to local, national and international business, news and entertainment, but also allow cost effective and extensive social services as well. Thus, broad band satellite communications of the 21st century will offer amazing new opportunities for tele-education, tele-health, and other tele-services by governments, information networking by non-governmental organizations and aid agencies, and hundreds of other innovative uses. While there are tens of millions of satellite based teleservices today, one can anticipate hundreds of millions of students obtaining satellite tele-education services in another few decades.
2.0 The Major Drivers of Change in Global Satellite
Technology
Major
drivers of change in the overall field of telecommunications include: (a)
competition, (b) deregulation, (c) new technology, (d) new types of
applications and service demands, (e) globalism, and (f) convergence of
technology, services and markets.
Not too surprisingly these same forces are the key bases of change in
the world of satellite communications as well. For satellites the new regulatory framework driven by
competition and deregulation and new technologies and services are of
particular import.
2.1
Competition, Deregulation and "Bypass"
The end of the era of the so-called "natural
monopoly approach" to telecommunications ended in the mid-1980s. In rapid fire fashion many of the
largest and most advanced economies in the world moved to privatize
telecommunications entities (where relevant) and create competition in the
provision of networks and services.
In the United Kingdom, New Zealand, Australia, Canada, Germany, Japan,
and the United States these major shifts occurred first. Now virtually all of Europe of the
Organization of Economic Cooperation and Development (OECD) is subject to
telecommunications competition and overall some 80 countries have signed on to
the General Agreement on Telecommunications Services (GATS) of the World Trade
Organization. Under this GATS
framework, competition, deregulation, and privatization are being implemented
and even this is being accomplished at different speeds and to different
degrees. This has served to open
up new opportunities for satellite services with more direct access by business
users and consumers to space based services.
This global trend is particularly relevant to
satellite communications and wireless systems because these technologies are
most adept at bypassing the established terrestrial cable and wire networks of
the established former monopolies.
Increasingly the new competitive environment forces new competitors to
deploy the most advanced and cost-effective and flexible technology to compete
with established wire, coax or fiber-based networks. It is the narrow-band, copper wire based
"last-mile" part of the older networks that are most vulnerable to
competition by satellite networks.
It is in the "last mile" contest for higher speed access
(heightened by the need for faster connection speeds to Internet) where the
newer, broader band and wireless networks can be effective. It is this market in particular that Ka
and Q/V band satellite systems such as Hughes Spaceway, Loral Cyberstar, and
SES Global, etc., hope to capture.
Terrestrial wireless systems including third generation Personal Communications Services (PCS), as well as so-called "wireless cable services," i.e., MMDS and LMDS, are likewise trying to compete with terrestrial cable and wire systems by being able to bypass the local cabling and go directly to the desk-top or the subscriber's hand-held units. Finally mobile satellite systems such as Globalstar, New
Iridium, New ICO, AceS, Thuraya and other such systems are seeking ways to
provide voice and Internet services directly to users around the world.
This new environment places the regulatory officials
in a new role. Rather than trying
to control tariffs or investment, the challenge today is to encourage
competitive services to the consumer and to penalize anti-competitive behavior
through fines and other controls.
The official regulatory agencies such as the European Union, OfTel of
the United Kingdom, Austel in Australia, the FCC, and particularly the World
Trade Organization (WTO) on a global scale are, in their various ways, working
to create a number of incentives to encourage new competitive market
entry. In fact, in Europe the
first step to greater competition in the European market began with the
European Union's Green Paper on Satellite Communications in the 1980s. The French Space Agency (CNES) has even
taken the unusual step of investing in new satellite communications ventures.
In short, the satellite industry that was once under
the control and dominance of the large telecommunications monopolies and
greatly favored wire and cable technologies are now the main beneficiaries of
inter-media competition. Although
fiber optic cables are highly cost efficient and provide huge throughput
applications they are limited in their ability to support mobile applications
and service to rural, remote and rugged terrain locations.
At the same time, the various satellite systems are
being used not only for business, news and entertainment, but increasingly for
social services, particularly for distance learning and tele-health
applications. New technology and
new broadband applications are leading the way.
2.2
New Technology and Services
One of the key puzzles of the day can be likened to
the old riddle of whether the chicken or egg came first? In the age of modern satellite
communications the question is whether advanced digital communications satellite
created the new competitive market structure or did the new environment allow
satellite systems to blossom. The
answer seems to be that this was a powerful symbiosis that was mutually
reinforcing. Despite the rapid
development of satellite communications over the last few decades, the
explosion of technology is far from complete.
Some of the most important technological developments
are still to come. Within a decade
or so there will likely be new very high power (25 to 60 KW) Multi-Purpose Digital
Satellite Buses capable of providing all forms of telecommunications services
at bit rates in the gigabits/second to the terabits/second range. The ancillary to these extremely high
frequency and high power space buses will be terrestrial transceivers that are
highly user or consumer oriented.
This means the advent of so-called hand-held portable or even
"wearable antennas" and broadband micro-terminals that shrink from
about 65 centimeters (2 feet) in diameter down toward the size of a cigarette
pack. Here electronic tracking
user terminals (i.e., phased-array and patch antennas) will be key. This pattern of "Technology
Inversion" (i.e., making space systems larger and more powerful while
ground transceivers shrink in size and power) will also allow cell phones to be
sufficiently low in power so as to ensure human safety.
During the first decade of the 21st century one can
also anticipate that so-called High Altitude Platforms Systems (HAPS) with huge
capacities for mobile telecommunications and television entertainment will be
deployed over large cities. Even
further in the future, it seems likely that high capacity low earth orbit
multi-media satellites will be interconnected to HAPS platforms via satellite
cross-links to create Hybrid Space/HAPS networks. In this case the satellite part of the system will create
low-latency global interconnectivity while the HAPS wireless systems will
create huge localized capacities over dense traffic urban areas. Also in the post 2010 time period, very
high capacity optical space communications systems operating in the
space-to-earth and earth-to-space mode could also provide a new type of space
systems as well.
What is not as clear is whether extremely large
geosynchronous satellite antenna farms, perhaps acres in size, can achieve the
same or larger capacities as fiber optic systems. In the satellite world the trend seems to be to move to
higher and higher frequencies that can support higher information throughput
(i.e., using the Ka, Q/V and W bands and/or the development of large multi-beam
satellite systems) that are capable of achieving 100 fold frequency re-use
opportunities. This torrent of
technological change suggests that creating effective standards for seamless
interconnection of space and terrestrial systems will not become any
easier. In short while the
technology will bring lower costs and broad band services to an ever growing
market, the regulatory, standards, and frequency allocation problems will
probably become even more difficult than today.
2.3
Technology and Satellite Markets
The world of satellite communications has changed dramatically in only the last decade and will change even more in the decade ahead. Currently satellite communications services represent about $35 billion/year today and are expected to reach some $75 billion/year by year-end 2005. It is a very large and growing industry that is increasingly international in scope and ownership. The satellite systems being designed, prototyped and "mass-produced" have higher and higher speed and as lower and lower cost (although launch costs have stubbornly resisted major cost and price reductions).
New
or revamped satellite entities have entered the field from locales as diverse
as Korea, Israel, Brazil, Russia, India, Indonesia and China. New approaches to satellite
communications are everywhere.
These new approaches include high-powered solar arrays, on-board
processing, signaling and re-generation of digital signals. They also include new types of orbits,
mass production of satellites and micro-terminals, use of new Ka and Q/V bands,
phased array antennas, and intensive re-use of frequencies.
These
new technologies and systems concepts have redefined the scope and reach of
satellite communications, allowed them to compete with fiber optic
communications systems in new ways, and most importantly have allowed them to
provide direct services to consumers.
The "satellite bypass revolution" that allowed individual
consumers to buy direct-to-the-home entertainment, mobile communications via
hand-held units, and provided communications and tracking to trucks, buses, and
trains is perhaps the most important change of all. These changes were allowed more by revisions in laws and
regulation than by new technology or systems concepts.
2.4 Totally New Satellite
Technologies and Systems
In concept the satellite
communications technology of the 21st century could evolve in many
ways. These include the
extrapolation of current satellite technology so that it simply gets bigger and
better. This, however, seems
unlikely because the demands of the marketplace suggest that new technologies
and new efficiencies are needed both in space systems and particularly in terms
of new more cost efficient user terminals.
There are also prospects of new types of orbital systems, but recent
experience in the market place suggest that particularly low earth orbit
systems will be postponed due to technical challenges associated with broadband
switching and uncertain business models even though traffic on systems such as
Globalstar and New Iridium are currently growing well.
Yet another option would be to
develop new types of satellite architecture and antenna systems that could
produce major payoffs in terms of new cost efficiencies and new and more effective
use of spectrum. If one projects
current satellite technology forward in terms of mass, spectrum and performance
the likely design parameters would be expected to be as reflected in Figure 1
below. If it were possible to develop new technology and systems that reflect such a new type of architecture with very large aperture but low mass phased array antenna systems, then new, higher performance "breakthrough" goals for satellites becomes plausible.
At this time such large scale and high performance new
types of satellite systems would have to be
deployed in geosynchronous orbit since one could not achieve the needed scale
and broadband switching efficiencies in either Medium Earth Orbit (Meo) or Low
Earth Orbit (Leo) that would likely be required.
The research plan that is
implicit in the types of space systems implied by Figure 1 would likely have a
number of specific objectives:
Figure 1: New Goals For
Future Satellite Communications Development
These new
and quite demanding new space telecommunications development goals might
include the following:
(a)
Development
of 10 to 100 times more usable radio frequency spectrum for global satellite
telecommunications. This would be
derived from a geo- platform that would dramatically reduce the cost of all
types of space telecommunications and information services--private and public.
(b) Allow the
introduction of new forms of user friendly and highly compact
micro-terminals. These would not
only be extremely low-cost and low powered but also sufficiently small so that
they could be extremely portable or even eventually become wearable
devices. (The advent of very low
power user transceivers will also have a long-term health advantage as well as
an economic advantage. Progress in
this regard may have more to do with digital compression and vocoder technology
than satellite technology.)
(c) Create system
economies that would radically reduce the cost of global telecommunications
networks, broadcast and mobile services, and international tele-education,
tele-health, tele-safety and disaster warning systems.
In short the new and highly advanced satellite systems, would likely be based on large scale space telecommunications systems, that one might call "geo-platforms", because new scale and performance economies would likely not be achievable in lower orbits.
These new geo-platforms could
stimulate new public as well as private-sector applications and provide
economic breakthroughs in the cost of access to orbital spectrum. It could also aid in the creation of
new jobs and information services.
Discussion of possible new applications that these new space systems
might make possible are discussed later in this chapter.
Such advanced Geo-Platform designs could, in theory, involve the deployment of less mass and less complex systems in space than today's most advanced space communications antenna systems. More specifically these advanced systems might actually weigh about the same as today's largest satellites (i.e., about 5,000 kilograms), yet they could also achieve performance that is significantly better than today's most advance satellite designs. This assumption is based on the idea that there can indeed be revolutionary design capabilities in an advanced geo-platorm that departs from the trend line for conventional satellite design.
In order for such advanced design concepts to be successful they must be more than just competitive with today's communications systems, but rather they must seek to be competitive with telecommunications systems some 15 years hence. Further they must deliver system capacities and quality of service that would be compatible with system user needs that might be anticipated in the 2010 to 2020 so time period.
This is obviously a very difficult objective in light of the continued expansion of system users and exponential growth of broadband user needs as driven by high data rate Internet applications, growing numbers of terabyte databases as being deployed via Internet 2, the exploding use of multi-media applications, and the explosive global growth of e-commerce and worldwide radio and television broadcast systems.
It is therefore assumed that the prime driver of advanced geo-platform design will be the ability to deliver huge amounts of spectrum from orbit (orders of magnitude greater than today's satellites) and at commercially competitive prices. The key goal of this advanced system design study of an advanced geo-platform would be, in a nutshell, to find a cost effective way to greatly multiply access to "useable spectrum".
Demands for satellite services can be envisioned that are 10 to 50 times greater than today's service requirements. This new service demand would be in such areas as broadcasting, multi-casting, aeronautical safety, navigation and mobile communications, mobile applications involving multi-media over IP, and new broadband business, tele-education, tele-health and other social services. Figure 2 below thus summarizes some of the primary technology goals that future satellite systems would need to meet.
Figure
2: Key Technology Goals for Future Satellite Systems
-
Lower spacecraft transmitter power requirements and much lower user terminal
power requirements -
Implementation of many simultaneous independent beams - Less interference between antenna elements within a GEO "slot" - Significantly more frequency reuse within a GEO "slot" -
Significantly more capability with lower total weight and cost per voice or
video circuit -
Significantly greater on-board processing capability to utilize such
systems more effectively in meeting
consumer and business demand - Ability to service, repair, or
update elements incrementally
Future
Satellite System Goals
