Figure 1. Interaction between tele-medicine users
The world is currently witnessing a revolution in communication and information technologies. Concepts like global personal communications via satellite and the 'information superhighway' are becoming common terms in a growing information society. At the same time, basic education and health care are major problems for billions of world citizens. Expected increases in population in the most affected regions will worsen the situation.
In an effort to address those critical problems, participants in the International Space University's 1994 summer session have produced a proposal for GATES, a Global Access Tele-health and Education System. By using the advanced communications and information technologies in tele-health and tele-education applications, GATES aims to improve basic education and medical care on a global scale.
We are currently witnessing a rapid evolution in communication and information technologies. In many parts of the world, the uses of computers, mobile telephony and satellite communications are already key elements in an expanding information society. In the near-future, Low Earth Orbit (LEO) satellite constellations will offer mobile personal communications, at any time and place, using pocket-size terminals. Interactive high band-width services will be available at home, through satellite or fibre optics technologies. Multimedia computers are becoming standard, allowing the combination, manipulation and exchange of text, sound and images easily and at low cost. The arrival of these technologies will undoubtedly and considerably influence our lives within only a few years' time.
It is very likely that the dominating applications of these new technologies will be found in high-profit domains like business and entertainment. Major companies and international organisations are currently investing billions of dollars to secure their share of a huge commercial market. Primary areas of interest include business communications, paging, video-conferences, home shopping, video on demand, and virtual reality.
Other applications that are perhaps less profitable in traditional terms, but extremely valuable in a long-term global view, may also benefit from this evolution. Outstanding examples are distance education and health care in remote areas or in emergencies. Such applications have proven to have a significant positive effect on the affected areas by compensating for a lack of resources and infrastructure. The users needs and the requirements of these types of applications must, therefore, be considered in the development of new communication infrastructures.
Meeting the distance education and health care needs of remote areas was the focus of intense activity during the 1994 summer session of the International Space University, held in Barcelona. A group of 46 participants from 19 countries was challenged to propose efficient ways of using existing and future communication and information technologies in education and health care. The project was sponsored by ESA, NASA and several other major space organisations. After analysing the technical, political, legal, cultural and financial aspects of the problem, the international project team recommended an outline for a Global Access Tele-health and Education System (GATES). The aim of the system is to improve education and health care services, particularly in remote areas and developing countries. The proposed solution is based on the use of existing and future telecommunication and information systems on a global scale.
International Space University
The International Space University (ISU) was founded in 1987 as a non-profit, non-governmental institution
for the education and training of tomorrow's space professionals. ISU brings together international space
experts from academia, industry and government to educate students in multidisciplinary and advanced issues
in space development. With a permanent campus in Strasbourg and affiliated campuses in 25 locations around
the world, ISU offers educational programmes that range from an intensive summer session to a full Master of
Space Studies (MSS) programme.
One of ISU's annual objectives is to conduct design projects, such as GATES, that are of interest to industry and the space community and provide the students with a challenging problem. The material in this article is based on the final report and the experience of those participating in the GATES design project as part of the ISU'94 summer session held in Barcelona, Spain.
ISU summer sessions have previously been held in Cambridge, USA; Strasbourg, France; Toronto, Canada; Toulouse, France; Kitakyushu, Japan; and Huntsville, USA. In 1995, the session will take place at the Royal Institute of Technology in Stockholm, Sweden.
Despite global recognition that health and education are the essential building blocks of a sustainable society, serious shortcomings and maldistribution in education and health care services remain. A United Nations study estimates that two billion people have either minimal access to basic education or health care, or are completely lacking access to these services. Predicted increases in population, particularly in the areas most affected, will put even more strain on education and health care efforts in the future.
Limited access to educational and health care services is generally driven by complex economic, political, social and cultural factors. One technological project alone cannot hope to resolve such vast and complex shortcomings. It has, however, been demonstrated that technology can improve the situation. Modern telecommunications technology has the potential to play an important role in this situation, in particular given its ability to reach many people at a reasonable cost.
Tele-health and tele-education involve the use of telecommunication techniques to provide respectively medical or educational services over a distance. Common examples are a doctor in a remote area transmitting an X-ray image to a specialist thousands of kilometres away for consultation, or the use of satellite television to teach students in remote areas. These and many other applications have already proven to be feasible and effective through many local and regional projects.
In Europe, ESA has been active in distance education using the Agency's now-retired Olympus satellite. Its involvement in the Eurostep activities has been previously described (ESA Bulletin No. 56, 60 and 66). The European Union is carrying out other related projects, including the DELTA project for distance learning and the AIM project for telematic systems in health care. Many other projects undertaken around the world have shown that distance education can provide results of the same quality as classical classroom education.
Similarly, it has been shown that tele-medicine can be adapted to many situations, particularly in the case of emergencies, lack of qualified personnel or in remote areas. Examples of major projects already undertaken are:
The scope of the ISU design project was defined as reducing inequalities in health and education within countries and between countries by providing global access to health care and educational services using telecommunications technology . The unique aspects of the resulting GATES system are that it takes a global approach and it has the dual objective of combining education and health care.
In addition to the broad definition of the mission, the project group identified the high-level goals that were used as major guidelines for the study:
A global strategy was justified by the worldwide distribution of the short-comings to be addressed. Financially, a global system can be funded by combining available resources from many sources. This allows shared use of the system with regions less able to support high investment costs. Satellite telecommunications using existing systems in Geosynchronous Orbit (GEO) and future proposals in Low Earth Orbit (LEO) ensure technical feasibility and offer coverage of a global nature.
The dual approach, combining education and health care, is justified by the fact that the highest educational and medical needs generally appear in the same areas. Furthermore, the basic communications requirements for educational and health care services are very similar. The validity of this approach was demonstrated for example by Project SHARE, which provided both tele-health and tele-education.
The potential users of GATES can be divided into three categories: specialists, non-specialists and beneficiaries. A specialist is typically a medical doctor with expertise in a specific field of medicine, or a specialised teacher. The non-specialist is generally a doctor, a nurse or a teacher who is working in a remote area. The beneficiary is the patient or the student who receives the medical or educational service.
In a typical medical situation, a general practitioner (the non-specialist) working in a remote area seeks the advice of a specialist in a distant location to establish or confirm a diagnosis (Fig. 1). This method results in improved quality of the diagnosis, and allows the diagnostic time and the need for patient transportation to the specialist to be drastically reduced. Similarly, a teacher working in a remote area may call upon a more highly trained teacher, access stored information or make use of advanced audiovisual media to improve the quality or level of education offered where alternatives do not exist.
Non-specialists using the system to improve their own skills and knowledge by learning from more highly trained individuals is an example of the teaching teachers and teaching doctors concepts. These concepts are particularly important in regions such as developing countries where the qualification level and number of non-specialists like primary school teachers and nurses are often insufficient to provide all required services.
The patient or student, as beneficiary, has only indirect contact with the specialist. This keeps the number of user terminals required and the volume of communication to a minimum. Furthermore, an intermediate person (the non-specialist) will often be necessary since many patients or students do not yet have the skills to use the system.
Figure 1. Interaction between tele-medicine users
The message
For the user to accept a global system, it is important that the actual information or content of the
transmitted message is not defined centrally. It must be managed regionally or even locally to fit the culture and
priorities of the region.
The message will generally circulate between the specialist and the non-specialist. For medical applications, it will typically consist of information about the patient that is needed to establish a diagnosis or treatment. It may include images, voice, and digital data created by instruments such as an electrocardiograph, electroencephalograph, electronic stethoscope, ecograph, image scanner, or alphanumeric keyboard. For education applications, the message will typically consist of voice, images and digital data produced by a telewriter, image scanner, telefax or keyboard.
User terminals
The user terminal provides the interface between the user and the telecommunication link. Based on the
experience of previous tele-education and tele-medicine projects, general requirements rather than detailed
technical solutions were determined. The essential characteristics are flexibility, interactivity, modularity and low
cost. Furthermore, power autonomy, ruggedness and ease of installation are vital for remote areas, disasters
and emergencies.
A dedicated terminal that could be used for combined basic tele-medicine and tele-education in remote areas was studied. Based on existing computer and Very Small Aperture Terminal (VSAT) technology, this concept was considered to be feasible.
Telecommunication links
The telecommunication links must reach the user even in remote areas and regions lacking a
communication infrastructure. Furthermore, it must allow a sufficient flow of information to fit the application. This
is generally limited by the bandwidth of the link. The required data rate varies drastically with the level of service
to be provided but it appears that many basic services can be provided via narrowband links. The evolution of
data compression techniques, reducing the required data for a service without major loss of quality, further
increases the capabilities of limited bandwidth applications. A reasonable minimum service offering two-way
voice communication, data transmission (e-mail, fax) and still-image transmission capability is feasible with less
than 64 kbit/s per channel. More advanced applications such as video conferencing or compressed video
require minimum data rates in the range of 384 kbit/s to 6.3 Mbit/s respectively.
A technology review was carried out to identify the most adequate technical solution for GATES. Communication standards, analog and digital networks, wire and microwave ground systems, and existing and planned satellite systems were examined. It was found that although terrestrial telecommunication systems offer high capacity at decreasing cost in densely populated areas, they are not cost effective in remote areas where the population density is lower. In the absence of existing terrestrial networks, satellite systems were found to be the most effective way of providing the necessary communication links.
Proposed system architecture
To meet the requirements of both education and health care services, a system architecture based on
three levels of centres is proposed (Fig. 2).
Several High Level Centres are spread globally with at least one centre per continent. Each centre is to be located in a city or a region with a large hospital and a university. The High Level Centre is formed by electronically connecting the hospital and the university to form an integrated unit. This acts as a joint regional information source and focal point for both tele-education and tele-medicine. The High Level Centres are interconnected by high bandwidth satellite links or terrestrial connections to form the top level of the global network.
Each High Level Centre is connected by high bandwidth links to several Medium Level Centres. Each Medium Level Centre is also located in a city with health care and educational institutions interconnected to form joint local focal points. Due to legal issues, special needs and adaptability to cultural environments, at least one Medium Level Centre should exist in each country.
The Medium Level Centres are connected to several Low Level Centres, located where the medical or educational need exists. Since these locations may often include villages, remote areas and disaster sites, narrow-band or even mobile links may be required. The large number of links needed and their geographical distribution drive the requirements of the communication system.
Figure 2. Proposed GATES system architecture. There will be a least one High Level Centre
per continent. Each one will be connected to several Medium Level Centres. There will be at least one Medium Level Centre per
participating country, and it will be connected to several Low Level Centres located where there is a medical or educational need.
Three technical solutions
Three different technology scenarios were defined for the implementation of the necessary satellite links.
These options include the use of existing systems, planned new systems or a dedicated new constellation. The
general approach is to initially start providing services using existing systems. Once the system is working well,
a move to one of the various planned systems or a dedicated constellation could then be considered. The
choice would depend on the potential improvement in service versus the cost, which would be determined at
that time.
Use of existing systems
The initial solution, which would allow the global system to be demonstrated with minimum investment cost
and service delay, is based on the leasing of transponder capacity on existing geostationary satellites. An
investigation of 20 existing satellite systems showed that global coverage with identical ground terminals could
most easily be achieved using C-band frequencies. Existing Intelsat V, VI and VII systems would provide
sufficient capacity and compatibility with regional systems. The geostationary C-band solution is a low-risk
choice based on proven technology that provides acceptable performance for part of the required applications.
There are, however, drawbacks concerning power requirements, bandwidth, portability, transmission delays and
the cost of the ground terminal. The cost of the existing systems solution greatly depends on the negotiation
of the service charges. It is hoped that non-commercial rates would be applied, considering the international
and humanitarian characteristics of the application.
Use of planned new systems
The foreseen technology evolution in new satellite constellations may offer attractive potential for GATES.
Through technology evolution, smaller and cheaper user terminals or higher bandwidth services are becoming
feasible. Many proposed systems are based on large constellations in orbits relatively close to the Earth such
as LEO. This offers the advantages of shorter distance to the satellite, lower power requirements and cheaper,
smaller terminals. The disadvantages are the large number of satellites required for continuous coverage and
the complex technology requirements for coordination. This implies large investment costs, an uncertain
technical and financial feasibility, and unknown costs of services. Other proposals involve more traditional use
of GEO orbits, with potentially lower service costs. The proposals differ greatly in the bandwidth offered, which
determines the complexity of the possible application. Services range from inexpensive, low-rate data
transmission to high bandwidth links with interactive multimedia capacity.
An examination of several leading proposals for new systems was made based on the available information on costs and performance.
Depending on eventual realisation, the preferred options are (in order of priority): Teledesic and Hughes Spaceway for broad-band services, and Globalstar, Odyssey and Constellation for narrowband services. There is however considerable uncertainty regarding service charges and the actual implementation of the proposed systems, making the options difficult to evaluate at this time.
Use of a dedicated constellation
To study the potential of a solution tailored exclusively to the needs of the chosen application, a third option
was defined. This design is based on the implementation of a dedicated, relatively small constellation of
satellites. The ambitious solution is optimised to meet global coverage and the priority of serving developing
countries, both of which are fundamental GATES requirements. The proposed configuration of the dedicated
constellation is shown in Figure 3 and its ground coverage in Figure 4a & Figure 4b.
The design is based on eight 600-kg satellites equally distributed in a circular equatorial orbit (0 degrees inclination) at an altitude of 8000 km. In addition, four smaller satellites are placed in a polar orbit at the same altitude. The equatorial segment provides continuous service to the area between the 55 degrees North and 55 degrees South latitudes, which is where the majority of the world's population lives. The polar segment provides an extension to continuous global coverage. High elevation angles, enabling more compact and cheaper ground terminals, are offered in the area between the 30 degrees North and 30 degrees South latitudes, where most developing countries are found.
A wide range of launch options is feasible and a single Ariane-5 launch would be sufficient in terms of mass to launch the eight equatorial satellites. The radiation threat, however, is great at the chosen altitude, particularly for the equatorial satellites. Careful consideration was given to the necessary protective measures and it is estimated that a design lifetime of more than six years can be achieved.
With state-of-the-art technology, the total communication capacity of the payload can reach up to 6 Gbit/s per satellite in Ka-band. This results in a total system capacity that is potentially larger than the current Intelsat global satellite system capacity, at a relatively small fraction of its cost. GATES would require only 10% of this huge capacity, which creates a window of opportunity for cooperation with a commercial operator or an international consortium.
Figure 3. Configuration of the proposed GATES dedicated constellation
Ground coverage of the proposed constellation
Figure 4a. Coverage by the equatorial-orbiting satellites
Figure 4b. Coverage by the polar-orbiting satellites
Organisational structure
The challenge of implementing GATES can be considered to be more political and financial than purely
technical. For its realisation, a dedicated organisation driven by a humanitarian spirit while employing effective
commercial methods is proposed. Membership in GATES would be open to any state but all nations and areas
may have access to GATES services regardless of membership.
Services will be provided to commercial users at a charge while non-profit use will be subsidised. A hybrid structure, resembling that of organisations such as Intelsat and Inmarsat, is the preferred option for combining both profit and non-profit motivations. The desired characteristics of the organisation are tight management and low operational costs achieved by using minimum staff, competitive awarding of contracts, and volunteer workers. One coordinating office would be in charge of establishing the political and legal framework, managing the organisation, and dealing with frequency regulations and contractual relationships with the various partners. A sound use of the system will be assured by the creation of the GATES Code of Conduct, a set of rules to be followed by all users.
Implementation strategy
An implementation in three phases is proposed, starting with an initial preparatory phase expected to last
two to three years. The main tasks in that phase include the formation of an organisational structure and the
drafting of preliminary agreements between political, legal, financial and industrial partners in preparation for the
next phase.
In the second phase, the initial deployment phase, the first tele-education and tele-medicine services are demonstrated. Only a few sites are initially covered, using leased transponders on existing geostationary satellites. Early parallel introduction is suggested in Kenya and remote areas of Canada, expanding to regional coverage in these areas. Growth towards global coverage is prepared. The fundamental decision on the final technology option for the next phase, i.e. to use planned systems or a dedicated constellation, is made.
The third phase, the operational phase, features service growth towards full global coverage. The system is implemented in regions of Mexico/South America and South East Asia, followed by interconnection of regions globally, leading to full coverage. It is also expected that, in parallel with the geographical growth, the level of the services offered will increase due to technological evolutions and increases in link capacity.
Financial aspects
An exploration of potential financial sources identified the World Bank and other UN Organisations (e.g.
UNESCO), National Development Finance Corporations, organisations dealing with development issues and
space agencies as major potential contributors to GATES. In addition, commercial funding may be attracted
in the early phases by the perspective of large future markets for providers of user terminals. Considering the
yearly global budgets for education and health care, and the potential of GATES to effectively contribute in
these domains, it is believed that donations and low-interest loans could cover most of the financial needs for
the first years. The total expenditures for the first five years of service, using leased existing capacity, are shown
in Figure 5.
The estimated investment cost for the entire dedicated satellite constellation system is $1.2 billion US, which includes the space seg-ment, ground segment and launch. Both this cost and the offered capacity are, however, too high for GATES. To obtain low utilisation costs, the solution may be to offer the excess capacity to a commercial operator or an international consortium, reserving only a portion (e.g. 10%) of the system capacity for GATES use.
Figure 5. Total expenditures for the first five years of implementation using leased, existing capacity
In addition to global education and health care services, the establishment of a system such as GATES has the potential to contribute significantly to other applications. There can be direct benefits for disaster and emergency applications as well as in addressing environmental issues. In the domain of environmental protection, GATES can be a unique tool to foster environmental education and collect environmental data. Collaboration with other projects such as GLOBE (Global Learning and Observation to Benefit the Environment) would be directly applicable.
The tele-medicine aspect of GATES is an ideal contribution to the relief phase of disasters and emergencies. Experience shows that the time required to organise basic medical care and make an initial diagnosis is essential in reducing fatalities and aggravation of injuries. The combination of a disaster management system such as GEOWARN, Global Emergency and Warning (an ISU'93 project, Bulletin No. 77), and GATES forms an ideal solution for rapid and efficient relief. The two systems could share the communications infrastructure to reduce costs. Furthermore, the tele-education aspect of GATES would be directly valuable in disaster preparedness. Fatalities in under-served areas could be decreased simply through education on basic measures to take in case of disasters such as earthquakes, hurricanes or floods.
The current revolution in communication technologies will allow many new commercial applications in the near future. We must assure that their potential is also applied to improve the quality of life of billions of people, especially in the developing world, who need it the most.
GATES, the Global Access Tele-health and Education System, constitutes a practical way of using space systems to address some of the most dramatic human problems on Earth. This is an application that offers obvious benefit to humankind in a time when investments in space are being questioned by the public.
The idealism and enthusiasm of the team of students and young professionals who developed this project have not ended with the closing ceremony of the ISU'94 summer session. The team is now working hard to find support for the realisation of the project.
Participants in the GATES design project
Joël Amalric, France
Martinez Argüello, Spain
Adam Baker, United Kingdom
Yifang Ban, Canada/China
Kimberly Barker, Canada
Catherine Beaudry, Canada
Rita Crespo, Portugal
Paola d'Angelo, Italy
Nico Dettman, Germany
Alessandro Donati, Italy
Francesco Donnaloia, Italy
Claudie Durand, Canada
Jill Ferrier, United Kingdom
Anastasia Filonenko, Russia
Alessandro Fracchiolla, Italy
Philippe Gilson, Belgium
Caroline Guillon, France
Brian Hewitt, Trinidad & Tobago
Suwei Hu, China
Ryota Ito, Japan
Katarina Johnsson, Sweden
Norbert Knittlmayer, Germany
Carlos Liceaga, USA
Alvaro Lopez, Spain
Maria Martin Jimenez, Spain
François Mauivard, France
Sylvie Mouzin, France
John Mugwe, Kenya
Olivia Palmieri, Italy
Lluis Pina, Spain
Gilles Primeau, Canada
Fernando Ramos, Brazil
Beatrice Rossi y Costa, France
Marli Santos, Brazil
Grant Schaffner, South Africa
Vittoria Senes, Italy
Michele Shemie, Canada
Jean-François Simard, Canada
Manuel Sola, Spain
Nikolaus Steinhoff, Austria
Gerald Supper, Austria
George Tahu, USA
Hans Ten Cate, USA
Kristin Valle, Norway
Kristen Youngman, USA
Ram Jakhu, Canada
Joe Pelton, USA
Pär Edin, Sweden
Patrick Rebholz, USA
ESA Bulletin Nr. 81.