Using space for education: direct broadcasting systems.

Technology expected to improve rapidly

From a technological viewpoint, the use of direct broadcasting satellites for educational purposes is feasible. Direct broadcasting satellites and earch stations are operational. The technology is expected to improve fairly rapidly in the near future, particularly in the 12 GHz band, resulting in lower costs for satellites and small receiving stations and making direct broadcasting economically attractive.

A direct broadcasting satellite relays signals from one or more originating earth stations to many small, low-cost receiving stations. The receiving station may provide signals either directly to home or community television sets or for local distribution by cable or by rebroadcasting, and generally has no capability for transmitting signals to satellites.

Using satellites results in lower costs for coverage of larger areas with few or no existing transmission and distribution facilities. For large areas, a satellite system operates at less expense than a terrestial system. If there are enough receivers in the area, the cost of community rebroadcasting stations or cable distribution systems would more than be paid for by savings resulting from use of ordinary television receivers.

A direct broadcasting system may also be preferred for remote, rural and unserved areas, or to provide a "national channel" or university-level broadcasts to all the colleges in a country.

Having a single broadcasting channel for an entire country can be a disadvantage if independent local programming is desirable, as it is not possible to broadcast separate programming simultaneously to different areas on a single satellite channel.

Educational broadcasting outside of the formal educational system, whether in the form of pre-school education, correspondence courses, general adult education or continuing adult education is being successfully used in a number of countries. It seems particularly suited to part-time education. Its value in providing basic elementary education for children with no access to regular schools is not clear.

A number of projects using broadcast television as a primary component of school education have encountered major organizational difficulties. Since these difficulties are not technological in nature and only partly economic, they will not be solved simply by introducing direct broadcasting satellites.

The future of educational direct broadcasting within existing educational systems depends on the future role of television in a system. The introduction of new media technologies into as fundamental a part of a country's culture as the education system is likely to be feasible and desirable. Any country should undertake small-scale pilot projects before launching a large-scale satellite-based project.

Efforts should be made to make earth station technology available to all developing countries planning educational broadcasting systems, and to enable developing countries to participate to the maximum extent feasible in the design and construction of receiving stations for their own use and for the use of others.

For most countries, using a direct broadcasting satellite only for educational purposes is not currently economcally feasible. Countries interested in educational direct broadcasting should therefore consider providing channels for this purpose on communication satellites, multi-purpose satellites, or regional or international satellites.

While interested countries and regional groups could consider domestic and regional systems, international organizations could consider the possibility of an international direct broadcasting system offering channels on a short- or long-term basis to interested countries--providing access to developing countries for educational programming on favourable terms.

Costs: The cost of a direct broadcasting satellite space segment depends primarily on the number of satellites, the number of channels and the level of power. While a direct broadcasting system could operate with a single satellite, the significant possibility of failure of a satellite, either on launch or in orbit, induces many operators to build two or three satellites. To ensure continuity, it is common to have one operational satellite and one spare satellite in orbit and a second spare satellite on the ground.

Cost estimates for existing systems, depending on their sophistication, range from $35 to $140 million. Additional costs for launching the satellites, running into the tens of millions of dollars, must also be incurred.

The costof an operational direct broadcasting satellite system might be a minimum of $200 million to cover three satellites, two launches and the ground control and transmission facilities. Costs of associated receiving stations, programme production and support activities for a large-scale operation would also be substantial.

For many developing countries, these costs may be greater than the total national budget for education and could not be diverted from present activities. For most of them, these costs would have to be reduced in order to be economically feasible. This could be done through sharing of the cost of the satellite, either with other domestic services or with other countries or both.

A significant cost for programme production, broadcasting and support services must be met. The SITE programme, for example, using simple equipment but including graphics and on-location recording, produced 1,400 hours of programming for about $4,000,000--$3,000 per hour of programming. About two thirds of this was for hardware, one third for production costs.

Time-sharing: Countries could also use a channel part-time, with other countries using it at other times. The Canada/United States Communications Technology Satellite (CTS-Hermes), was shared on an equal basis by those two countries and the France/Federal Republic of Germany Symphonie satellite system is financed and shared equally by those two countries. The Symphonie satellites were also used for experiments in 33 other countries.

Time-sharing of channels depends on agreement on time slots for each country. For example, one country might use the satellite for daytime school programmes and a second country for evening adult education programmes, or both the day and evening periods could be divided into two time slots. Sharing could be facilitated if the countries were several time zones apart, thus allowing both countries to use the most desirable local times such as early evening.

The sharing of actual broadcasts by two or more countries wouls substantially reduce costs, but would require similar cultural, educational and socio-economic systems. It would not necessarily require a common language, but the absence of one would significantly add to production costs. Shared programme production might be most easily established on the basis of existing organizations for regional cooperation. The countries of the Arab League have adopted such an approach in the Arabsat sytem; the Tele-X System and the proposed follow-on Nordsat system are intended for common programming for Scandinavian countries.

Programme exchange: Exchange of educational programmes between countries can reduce the cost of programme production, and provide more variety in programming and provide programmes that could not be produced domestically. Science or mathematics programmes could serve the needs of many countries; foreign programmes on geography, history and culture could be useful in different countries. Imported programmes might prove valuable for study of foreign languages.

Imported programmes may also pose difficulties with regard to accent, idiom and even the examples or analogies used. There is also the question of whether even educational programmes are completely value-free and, if not, whether importing programmes also implies importing the associated values. Each country must produce indigenously as much of its educational programmes as possible, and imported programmes should be used after due screening and caution, according to the report.

Educational uses: A major limitation of television as an educational medium is that itis most often used in a one-way mode. Some experiments have been carried out to introducean interactive element by providing a return audio link either via satellite or through terrestial channels. However, this involves a large additional investment and may not be worthwhile except for special applications or circumstances.

The lack of interaction affects not only the student, but also the educational programmes. Some form of feedback is considered an essential component of an educational direct broadcasting system.

While technical difficulties and costs have posed some problems, the main obstacles have been organizationa, in particular, the problem of integrating television into the traditional educational structure. Many educational television projects using terrestial broadcasting in developing countries have been terminated or substantially reduced for a number of reasons, including teacher resistance. Direct broadcasting satellites should not be expected to revolutionize education, at least not in the short term.

Some experts believe that fully qualified teachers are required in classrooms, and that television programming should be used to enrich curricula. Others have concluded that television can present all of the instructional material, including exercises, and elicit active responses from students. A minimally trained "monitor" can ensure the necessary organization and order in a classroom, they feel. Their view is that existing teachers should not be replaced, but rather that classroom education could be expanded in areas where enough qualified teachers are not available.

Where broadcast television has been used to introduce new forms of education outside of the traditional classroom system, there has been less resistance to the new technology. In these cases, educational radio or television may be combined with readings and exercises arranged by correspondence and/or periodic direct student-teacher contact. The Open University (United Kingdom) and the Radio and Television Universities (China) are examples of such systems. Similar programmes exist in Australia, Canada, Indonesia and the USSR.

Because of the high cost of television systems and varying educational objectives, individual countries may wish to consider alternatives. Audio services, data transmission by teletext, videotex or slow-scan television warrant consideration. Combinations of these will be possible via satellite, either through direct-to-home broadcasting, broadcasting for community or school reception or distribution for terrestial rebroadcasting or cable distribution.

Technologies, however attractive, must not "drive" whatever system or systems are chosen. Educational radio, used for more than 50 years, and educational television, used for more than 30 years, have been historically under-utilized. Worldwide there is a need to develop the critical elements of any system: software, personnel and suitably designed programming. Using television to replace existing personnel or facilities does not appear either feasible or desirable. Rather, educational television has been used to improved the quality of instruction in existing educational systems, to expand existing systems to reach more students, or to provide new systems for people not served by existing systems.