Figure 1 : Teleconferencing via satellite and terrestrial links
3: DIGITAL SATELLITE TV & DATA TRANSMISSION
Steve Wheeler
Training Manager
RATIO Project
Ray Winders
Telematics Consultant
RATIO Project
University of Plymouth, UK.
The last decade has seen a gradual merging of technologies to produce a new discipline known as telematics. Telematics is essentially the convergence of several technologies, but notably TELEcommunications and inforMATICS (1). One project, RATIO (2) aims to use telematics based technologies to establish a network of innovations centres across the economically disadvantaged rural areas of Cornwall, Devon and Somerset. This article reviews the use of one such technology employed by RATIO - satellite TV and data transmission.
Satellites have the capability of delivering live educational and training programmes and data transmission simultaneously. Most telematics media are used for individual and small group activity enabling a tutorial function to be carried out at a distance. Satellite transmission is used for presentations normally to a live audience and enables lectures to be delivered at a distance. There is no limit to the number of receive sites. Since the cost is in the transmission the greater the number of sites and participants the more economic is the delivery. The breakthrough in cost has come with digitisation. It is now possible to transmit a broadcast standard television signal throughout Europe for a satellite cost of £150 per hour. For the first time satellite transmission is feasible even for relatively small numbers of students. This is particularly relevant in health care where those requiring specialist post registration courses and updates can be provided with high quality education and training in their own locality. (3)
Satellites and their most popular deliverable, television, are now a familiar feature of life in industrial societies. Most individuals by now are aware that global information can be easily accessed by the simple installation of a satellite antenna dish and a decoder/receiver connected to a domestic television screen. The first satellite, USSR’s Sputnik was launched on October 4th, 1957. Sputnik was essentially an orbiting radio transmitter, and was limited in both function and lifespan. 40 years on, satellites are finally coming of age as the most extensive, advanced and versatile communications hardware in existence.
Characteristics of satellite transmission
A satellite transmission (sometimes referred to as 'uplink') broadcasts a signal to one of the many communication satellites stationed above the equator at a height of 36,000 km. This is known as the Clarke belt since Arthur C Clarke wrote a science fiction article in Wireless World in 1945 which forecast that bodies stationed at that height above the equator would remain in geosynchronous orbit. (4) They achieve this by matching the angular velocity of the Earth, thereby remaining above the same point on the earth’s surface as it rotates.
The satellite signal consists of a broadband video channel and normally three audio or data channels with a total bandwidth of 34 megabits. A digital encoder can now be used to digitise and compress this signal to about 2.5 megabits. This enables several channels to be transmitted on the same satellite transponder for commercial broadcasts to homes but it also means that educational users can rent a portion of a transponder thus reducing costs by a factor of ten. The transmission can be from a television studio or from an enhanced lecture room. Most educational broadcasts are live with questions being asked to the studio experts via telephone or videoconference. The session including the questions can be recorded for future use, for example by those who are not able to attend the viewing of the live session. The receive equipment at each site consists of a small satellite dish (usually between 1 and 1.2 metres in diameter) linked to a satellite receiver or digital decoder which feeds a television set and video recorder. If data is being transmitted the receiver also feeds a computer.
Figure 1 : Teleconferencing via satellite and terrestrial links
Bearing these characteristics in mind, the present applications of ODL satellite techniques are timely for a number of reasons:
The first experimental geostationary satellites were launched in 1963. The first commercial service on satellite began in 1965. Growth has been rapid and at present there is concern over the number of satellites, some of them obsolete, which are orbiting in space. In Europe an impetus was given to educational satellite broadcasting through the launch by the European Space Agency in 1989 of the Olympus satellite. The satellite was available free of charge for experiments including educational broadcasts. Two uplinks were provided by the Space Agency located at Vilvoorde in Belgium and at Polytechnic South West - now the University of Plymouth. Institutions combined to provide six hours of programmes per day through the EUROSTEP consortium. The University of Plymouth pioneered live transmission through a Department of Employment initiative called STARNET. 52 live programmes were delivered in three series: Business Start-Up, Computer Integrated Manufacturing and a series on special topics including Computer Viruses, Green Consumerism and Safety for Divers.
Since the loss of Olympus the University of Plymouth has continued to provide a service using the European Space Agency (ESA) uplink. There have been a small number of other users Europe notably EUROPACE and EADTU which are consortia of university providers. The cost of satellite transponder time has been a major inhibiting factor but the advent of digital transmission should give a new impetus. In the USA large scale developments have taken place. The National Technological University transmits satellite led degree programmes at full cost in a range of subjects and several other universities transmit programmes at postgraduate level including training direct to company premises.
Evaluation and theoretical base
The STARNET project described above was evaluated by Diana Laurillard of Open Learning UK. (5) She recommended the following criteria for successful live broadcasting by satellite:
1. Programmes are relevant to students’ and trainees' needs.
2. Participants receive briefing and debriefing and integrated study material to follow up the issues raised in the programmes.
3. Participants are able to attend all the group viewings of the programmes at the transmitted times.
4. A local site facilitator is available to supervise technical set-up and to provide control and encouragement of use of the audio bridge.
5. The local institutions value and give support to the medium.
6. An understanding of the subject is enhanced by detailed and anecdotal discussion and argument, or the subject matter is topical and requires immediate delivery, to ensure that benefits are maximised.
7. Participants are likely to value each others’ questions and viewpoints, to ensure that benefits are maximised.
8. Participants are located near to a satellite receiving station to reduce their time costs.
9. Delivery costs can be shared with other projects also requiring satellite reception.
10. Programme production costs are commensurate with audience size.
These criteria have been observed in more recent transmissions. The theoretical base of satellite transmission is that it provides a third strategy for teaching and learning. (6) The first strategy, traditional teaching has been face to face with some emphasis on drawing out the student and creating a group empathy. Conversely, the second strategy distance learning is characterised by an industrial approach. In the Open University UK a subject team and a team of educational technologists decide on the content and teaching strategies. Following trials a large scale production and distribution process begins. There are two drawbacks; there is a time delay between origination and receipt by the student and there is no facility for updating until the next edition. Though for many subjects delay is not crucial, in others up to the minute information is essential. In computer applications even last week’s information may be outdated.
Satellite transmission provides a third strategy in that sessions can be presented live at a distance. Some of the qualities of the prepared session are available especially in studio broadcasts where graphics and location video can be used to enhance the presentation. Moreover the audience can interact and contribute to the session as in a face to face lecture. If videoconferencing is used as a feed to the transmission, experts from a distance can be incorporated into the broadcast for specialist live contributions. Such programmes can be supported by later videoconference or computer conferencing as well as printed materials. This quality of live at a distance interaction means that the very latest subject specific developments can be included. For example, a programme on prophylactics for malaria can include that morning's announcement on the latest developments in drugs. In summary there are six special advantages of live satellite transmissions for education:
1) A high quality programme can be created using video inserts and computer graphics.
2) The programme is up-to-date because it is live. Latest techniques in post-operative care can be shown to all.
3) There is immediate interaction and feedback from the learners by videoconference, telephone or e-mail.
4) Reception is simple. No cabling is required. The technical specification of a community health centre is equivalent to that of a central London teaching hospital.
5) Production costs are low because the programme is live. There is no post production editing. Deadlines must be met because the programme is scheduled.
6) The programme itself provides a stimulus for group discussion and an occasion to meet. It can be an update for on the job training or integrated into a degree or diploma programme.
Programme examples
There are several examples of face to face at a distance satellite transmissions which can be outlined briefly here:
Solstice (7) was a project funded by the British Library to investigate the cost effectiveness of training delivery by satellite. Librarians in Higher Education carry out searches on electronic databases such as the British Library’s BLAISELINE for which training is required in the form of a three day intensive course at the British Library centre at Boston Spa in Yorkshire. Including travel this means that the specialist librarian is absent for a week, causing considerable disruption to the service. Two tutors from Boston Spa delivered the course by satellite to twelve regional libraries. The recipients watched the transmission on the television receiver but also had a BLAISELINE terminal adjacent. The tutors demonstrated a specific search procedure and were able to transmit the complete BLAISELINE screen live including movements of the cursor as a selection was made. The demonstration was followed by an exercise during a break in the programme.
The participating groups were able to view their own results on their BLAISELINE screen when, in the second part of the programme, the tutors discussed and demonstrated the correct result on a parallel television screen. Evaluation showed that the participants rated the training as equivalent in quality to face to face training but at a significant saving in travel costs and disruption. An unexpected bonus was that the groups of librarians working together on each site were able to help each other during the programme and offer mutual support afterwards. Normally only one member of staff is sent for training. A second advantage mentioned was that staff were trained on their own equipment in their own context. Some stated that what was clear to them on previous courses at Boston Spa seemed qualitatively different on their return to base a week later.
This series from the University of Plymouth featured students discussing with a tutor their own techniques for learning success. A student who had won a national essay prize described her full process in detail from analysing the essay title through to presentation on the page. In one programme on presentation skills a group of students described the process of group work and group assessment. They were forthright in their analysis of how a lazy group member should be treated. A group of mature women students described how they worked together in the early stages of an assignment to ether information and conduct literature searches. Several live forum sessions featured recipes for learning success from students and academic staff alike, and all the programmes featured live audio conferencing and questions from remote sites. Evaluation of the series showed that other students valued the programmes because of the student participation, commenting that it was not ‘just another lecture’.
Satellite transmission is particularly valuable for training in all aspects of computing. Software in particular is updated regularly by manufacturers so live programmes providing the very latest information are important.
In one series on desktop publishing transmitted from Plymouth each stage in the build-up of a brochure page was demonstrated live. This was part of a series in which a beginner sat beside the expert in studio to ask questions and encourage questions from viewers at a distance.
In the next series the demonstration will be supported by individual on-line tutorials using shared screen facilities. This can be provided using a standard computer modem and telephone link. In RATIO Centres shared screen techniques are achieved using ShareVision, a video conferencing system which also features a small camera linked to the computer to provide a ‘face to face’ dialogue.
Mediaspace, a distance learning course in multimedia is the University of Plymouth’s contribution to a European Association of Distance Teaching Universities (EADTU) - a European funded project that is evaluating the latest applications of information technologies. Mediaspace is the most innovative course yet delivered due to its powerful combination of technologies. A monthly series of live broadcasts replaces the lecture mode, where group and individual tutorials are provided using First Class, an electronic conferencing system, ISDN videoconferencing and file transfer. Participants can also gain access to a web site. The live programmes use a ChromaKey technique to make the experts appear as part of a computer screen. As well as world class experts and company representatives present in studio other experts made live contributions to the programme remotely via ISDN. The students throughout Europe preferred to ask questions using the First Class electronic conferencing system, possibly due to its less threatening nature. This also enabled the presenters to organise the questions and answers at convenient points in the live programme.
Regional developments
1) RATIO
This project has secured just over £5 million from European funding and partnership organisations throughout the South West region to establish 40 telematics drop-incentres. Each will be equipped with leading edge technologies, including super highway technology, video conferencing, computer networks (8) and digital satellite television and data reception. The centres will be open to the public and in particular the project is aimed at regenerating the fortunes of local small businesses. RATIO will provide the means of disseminating high quality information and training products direct from the providers to the users. Satellite technology plays an important role in this undertaking, as transmissions of video, sound and data can be received by all the centres simultaneously, and all users can be linked if required by terrestrial links back through the main studio.
The University of Plymouth has won the contract to provide health care training throughout the South West replacing the former Schools and Colleges of Nursing in the Region. A new Institute of Health has been created incorporating many of the staff from the former schools of nursing. Education and training will be delivered on four campuses at Truro, Plymouth, Exeter and Taunton. An important component of this project will be the provision of eight local study centres based in community hospital locations from Wells in Somerset down to Penzance in West Cornwall. The distance from Wells to Penzance is equivalent to the distance from London to Manchester so telematics will play an important part in course and information delivery for pre- and post-registration students alike. Each main campus and peripheral study centre will have digital satellite television reception together with videoconferencing and computer networks. Trials of the new technologies begins in September 1997. The study network will be increased for some community programmes and updates by using the 40 RATIO Centres in parallel with the Institute of Health's own centres.
This paper has so far featured the use of satellite transmission for live television programmes. However, in addition to video, satellite transmission includes three audio or data channels. One of these is used to carry the programme sound and, on occasion, a second has been used to carry a second language in simultaneous translation. The University of Plymouth’s satellite research centre has developed a PC card which is installed in a standard computer and cabled to the data output of the satellite receiver. Data can be transmitted on the third channel at the equivalent of 10 pages of A4 per second during the television programme (128 kilobits per second). This can be relevant to the programme, for example study notes or brochures, or can be in the form of separate databases, or used to transmit updates for other areas of interest. The system will be used within the RATIO network both to deliver course notes and to deliver tourist information, job vacancies, government publications and so on. The system is managed in a Windows environment which enables the data to be sent to all centres simultaneously, or to any selected audience using an identification ‘PIN’ number unique to each centre's card. The Institute of Health will also use the system to send information and regular updates simultaneously to each of its centres.
As the quantity of information expands expertise becomes necessarily more specialised. No one tutor can possess the breadth of subject expertise required. Telematics can bring the most recent developments and techniques direct to the most remote location. The local tutor and student can ask questions directly to the experts. Costs are falling continually, with digitisation and compression leading to smaller and cheaper transmission and reception equipment. Stephen Ehrmann (9) has examined the potential for telematics in post secondary education and training in the USA and as a result, has llisted four key features:
1) Use of familiar technologies rather than those specifically designed for education.
2) Stimulus sessions delivered by first class exports.
3) Access to tutorial support at any time, for example by e-mail.
4) Networking and co-operation between providers.
An opportunity now exists for any education
or training provider in the UK to make use of satellite and associated
technologies to provide live face to face education at a distance.
Soon a set top digital satellite box will provide a choice of 200 extra
channels direct to the home. The authors believe that such powerful
technology outlined and the coming developments should not be left solely
for commercial exploitation, but should be siezed as an opportunity not
to be missed by educators and trainers alike. As the technologies
continue to converge, satellites will play an increasing role in the development
of ODL environments.
(1) Wheeler S. Convergent technologies and innovations in distance learning, Integrating Learning Technologies Conference, 30 January 1997, University of Plymouth, UK.
(2) Wheeler S. Distance education and new convergent technologies: video conferencing. ITIN 1997; 9.1: 19-21.
(3) Winders R. Satellites in Information Management and Technology in Healthcare. In Britain J M and Abbot W. (Eds)., Taylor Graham. London. 1993
(4) Clarke A.C. Wireless World. October 1945. Extra-terrestrial relays - Can rocket stations give world wide radio coverage?
(5) Laurillard D. STARNET Evaluation, Project Final Report. Department of Employment, Sheffield. 1991.
(6) Winders R. Face to Face at a Distance. In Bell, C., Bowden, M., and Trott, A., (Eds) Aspects of Educational & Training Technology XXIX, Kogan Page, London. 1997.
(7) Millard P. The Solstice Project; Report 6072. British Library Research & Development Department, London. 1992.
(8) Magee R., and Wheeler S. Distance education and new convergent technologies: computer mediated communication. ITIN 1997; 9.2: 13-17.
(9) Ehrmann S.C. ‘Flashlight’, Change Vol.
XXVII, No2, pp: 20-27. 1995.
ODL . abb. Open Distance Learning
Telematics. The convergence of telecommunications,
computers and other technologies.
Footprint. The beam coverage of
a satellite transmission.
Geosynchronous. Matching the rotation
speed of the Earth - satellites need to be within the Clarke belt, ie 30,000
km above the equator.
ChromaKey. A television technique
using colour separation to create background image projections (used extensively
by weather forecasters).
Megabit. Measurement of data storage
and transmission. Mega = million.
Kilobit. Measurement of data storage
and transmission. Kilo = thousand.