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Introduction

In previous articles in this series we have explored the concept of RATIO and the potential of a range of telematic based technologies including video conferencing (Wheeler, 1997), computer mediated communications (Magee & Wheeler, 1997) and digital satellite TV and data transmission (Wheeler & Winders, 1997). An evaluation of each application has been offered, but without an overall strategy, the authors argue that no institution will reap the full rewards of convergent technology. It is only by the careful cosideration of a number of factors, including economic, social and psychological issues, that institutes can begin to exploit the full potential of new emerging technologies.

The University of Plymouth is a large institution, with over 16,000 full time students, engaged in higher education consultancy and research. It is located in the South West of England and covers the counties of Cornwall, Devon and Somerset, comprising several campuses separated at its widest point by 200 kilometres of mostly rural area. The University has developed a reputation for the delivery of distance learning courses using telematic technologies, including live, interactive broadcasts from its own TV studio and a TDS4 satellite uplink transmission facility on loan from the European Space Agency (Winders, 1993).

One of the University's departments, the Institute of Health Studies (IHS) is responsible for the delivery of pre-registration and post-registration nurse training, including midwifery, health visitor and district nursing courses. These are offered across the three counties from four main teaching sites. Recently, several tele-learning centres have also been established across the region, giving professional carers access to training and professional updates within or very close to the community hospitals and practices in which they work. This includes access to live satellite TV programmes in which acknowledged experts appear to present information and conduct interactive learning sessions.

These broadcasts offer interactive opportunities through the use of audio conferencing (analogue) and video conferencing (digital - ISDN) to enhance the learning experience of remote students. More than 800 live TV programmes have been transmitted since 1989 (Wheeler & Winders, 1997). The University's Satellite Research Centre has developed a sub-carrier data transmission system which can deliver computer data at 128 kbps simultaneously to distributed PCs, each equipped with data capture cards. Each PC capture card has a unique electronic identity, which enables selective transmission of data. This provides a high security facility for delivering sensitive content and enables course materials to be distributed only to bona fide recipients. This technique was originally introduced for wide band FM (analogue) broadcasts, and has recently been developed for transmissions incorporating MPEG2 digital video compression.

This results in a cost advantage of reduced satellite rental charges, since as little as one-eighth of the satellite transponder is required (Glover, 1996). In practice, this translates into an 80 per cent reduction in transponder costs which is a significant reduction.

Employing data transmission, students can receive course notes and up to the minute information relating to the study material, either during a broadcast or between broadcasts. The use of these satellite transmission techniques combined with computer and communication technologies has enabled the University of Plymouth to pioneer a number of innovative regional, European and global telematic projects (Vranch et al, 1997). This approach has also enabled the University to establish a regional network infrastructure in support of its distributed campuses and sites across the counties of Cornwall, Devon and Somerset.

Starting the process

A powerful combination of terrestrial and satellite services, including audio and video conferencing computer mediated communications and electronic mail, is now available to support learners studying at a distance. Feedback from students in the use of all these areas has previously been very positive (Hilton, 1996; Emms & McConnell, 1988; Ackermann, 1996; Huckle, 1996).

Particular attention should be paid to combining ISDN applications such as video conferencing, file tranfer and remote access techniques with the technologies of live satellite TV, web server and electronic conferencing applications. Used in the correct combination these technologies will offer the capability to mirror the functions of key-note lectures, alongside seminar/tutorial support sessions - with the emphasis in both cases on providing interactivity at a distance.

Furthermore, web servers can also be used to provide further links to other relevant web sites and access to files used in the transmissions for downloading. The use of ISDN video conferencing and/or other forms of electronic communication, can provide two means of communication , in addition to telephone and fax services, to enhance interaction during the programmes. In particular, ISDN video conferencing can be used as a means of bringing guests and viewers 'into the studio' from a distance to contribute to programmes.

The various operational features of the planned Institute of Health Studies telematic activities are illustrated in Figure 2, including the balance between synchronous and asynchronous working and the role of each technology in the delivery of learning materials, providing communication and access to information.

Technological convergence and distance learning

Previous projects and telematic experiments have provided valuable experience in the integration of computer technologies and networks for distance delivery of courses. Live satellite TV tranmissions exploit the quality of audio and video content appropriate to be received at a distance, and digital quality ensures high resolution pictures anywhere within the beam coverage of the satellite transmission. Interaction via telephone, ISDN videoconference or computer mediated communication/ electronic mail, can take place at any time during the transmission to bring in expert guests and for remote student questions. As course delivery has progressed it is interesting to note that students move away from video conferencing as a means to ask questions, and more towards electronic mail. Dooley (1996) has suggested that frequency of e-mail use increases in direct relation to the cognitive demands of the work. E-mail can be seen as a means to maximise interaction whilst minimising interruption, since the electronic mail interaction can take place unobtrusively during the live programme. Studio presenters can monitor questions from distributed groups of students, and tackle similar questions from several participants in one answer. On the other hand, integration of guest speakers can best be achieved via ISDN2 video conferencing, although the quality of video and sound are noticeably inferior compared with satellite television quality (Vranch and Wheeler, 1997).

These considerations demonstrate the range of network infrastructure options that can enable interaction. They also illustrate the advantages of using a combination of terrestrial and satellite technology networks to enable users to interact using appropriate modes. Although IHS telecentres will be equipped with standard facilities (digital satellite reception, ISDN video conferencing and Internet access) the option to interact from a range of technologies is important to deliver distance learning into regions that have varying levels of network infrastructure available.

One issue emerging from previous projects was that of bandwidth available for both send and return functions. The broadcast nature of the TV programmes was ideal for sending high quality video that comprised a major part of the course materials. Similarly, ISDN2 and low bandwidth terrestrial networks for electronic mail communication were adequate for effective return feedback and questions although the limitations of ISDN2 were noticed when guest experts were delivering content via video conferencing. The problem of limited two-way bandwidth was highlighted when students needed to collaborate on joint multi-media projects. High bandwidth communications in both directions are essential in this case to facilitate transfer of large multi-media files. IHS centres will operate at ISDN2 (128 kbps) send, with satellite data carrier delivery of learning materials (also at 128 kbps - i.e. up to 50 Mbytes of date during a one hour programme) which will assure symmetrical data transmission. That is, combining terrestrial network and satellite delivery can provide two way synchronous interactions at the same speed. This data has the capability to be encrypted. Clearly, this facility can be an advantage for regions with inadequate terrestrial networks or where data transfer with high security is required.

Previous telematic projects such as RATIO have illustrated the importance of good communications and interaction between staff working at remote centres on administration, training ad technical support levels. In particular, video conferencing (for meetings) and TV broadcasts (for staff training, marketing) have been important in this respect. With the scale of numbers (12) and dispersion of the IHS telecentres it is important to develop a community spirit among staff in the team. RATIO and IHS centres are all equipped with MPEG2 digital satellite receivers. This offers the advantage of operation at lower transponder costs compared with broadband analogue (FM) transmission. Digital satellite receive equipment is not widely installed at present, making the potential audience outside of RATIO/IHS currently fairly small. This may however, be an advantage in terms of exclusivity of course content on a course fee charging basis.

A concept map for benefits analysis

As a result of experiences an attempt has been made to visualise the various parameters that contribute to the successful delivery of distance learning courses. It is important to select appropriate technologies that are affordable, accessible and match the end-users' perceptions and expectations of quality of content.

The Benefits Analysis Map is an attempt to quantify three parameters: High Quality, Wide Access and Low Cost for delivery of distance learning via a single technology or via a combination of technologies and networks. This is intended as an aid in deciding which technologies are appropriate in the delivery of a particular distance learning course. The approach is at first student centred in that three parameters are considered from the student perception of the distance learning experience. However, the approach can also be applied equally to consideration of the three parameters from the viewpoint of the course provider (Vranch and Wheeler, 1997).

The example in Figure 3 shows the three parameters arranged in a triangle with the specified target minimum requirement zone (dotted line) and an example solution (unbroken line) plotted. Distances are measured from the centre, O, such that the distance OQ represents the extent to which the parameter High Quality has been met. The longer the distance OQ, the closer the solution meets the condition of 100 per cent High Quality. Similarly, the distances OA and OC represent the extent to which 100 per cent Wide Access and 100 per cent Low Cost are being achieved. The example plot must fall outside the target minimum requirement zone to meet all three parameters. In Figure 3, the example achieves the required level of Wide Access and Low Cost but fails to meet the requirement of High Quality. In practice, this simple example could represent the delivery of multi-media course content in 10 minutes via a 28.8 Kbps modem to a user in the UK. Equipment costs (user and provider) and line charges are relatively low, access to a telephone line is wide but the modem bandwidth is not adequate to deliver the large files within the time period required.

The more complex examples below provide a greater challenge to the application of this benefits analysis map approach and some discussion is included here. A more detailed analysis of these and other complex examples will be published elsewhere.

Potential for further integration of satellite and terrestrial networks

One important development at the University of Plymouth is the integration of the SWAN Asynchronous Transfer Mode (ATM) network and the satellite operation in support of nursing and health care students in IHS. The four main IHS sites are all connected to the SWAN network and enjoy a transmission speed of up to 155 Mbps, while the 8 study centres located in local hospitals are not connected to SWAN. However, as all IHS centres are equipped with digital satellite receivers, this provides a good, practical example of integration of satellite and terrestrial networks. Video conferencing and the relaying of lectures or seminars are both important to IHS staff and students in the distributed learning environment. These functions of course apply to student learning and staff administration or training needs alike.

The bandwidth available for one-way and two-way operation becomes important. For example, it is a straightforward prospect to deliver lectures from Plymouth to all centres via satellite, since all sites are equipped with receivers. The low transponder costs (for example, less than 400 ECU or £150 per hour) spread over 12 sites add to the attraction of this medium. Equally, the 4 main sites connected to SWAN can benefit from video conferencing services running across the network at, say, 2 Mbps, providing video and sound quality considerably better than ISDN2. Again, this improved quality enhances the acceptability of relaying lectures without the need to pay for satellite uplink costs, whereas SWAN is 'free'.

Notwithstanding, there is a rental charge for the ATM network, which carries voice and data services as well, and a true cost of the use of video conferencing over SWAN has yet to be calculated.

For IHS sites on SWAN there is the added advantage that the specialist lecturer can deliver from any of the four sites direct to the other three, thus adding flexibility. Satellite broadcasts must originate from Plymouth, where the uplink and studio are located, unless presenters are integrated into the programme at a distance via ISDN2 video conferencing. Again, the quality issue arises of using ISDN2 alongside the high quality TV output.

A development under consideration is to link the satellite uplink to the TV studio to provide an integrated terrestrial/satellite delivery system that overcomes some of the issues above. This approach would enable staff at sites connected to SWAN to present lectures that could be integrated (at high level video and sound quality) with satellite TV broadcasts to all centres in the network. Furthermore, with the link to SuperJANET the same principle could apply to include external guests as presenters at a distance.

Here again, the complex issues of one-way, two-way bandwidth requirements, access and cost come into play and prompt the application of the Benefits Analysis Map approach as a visualisation tool.

In a wider context, the potential introduction of ADSL (Asynchronous Digital Subscriber Loop) technology offers some attractions to distance learning delivery. ADSL provides an asymmetric bandwidth of, for example, 4 Mbps with a return bandwidth of 64 Kbps on existing twisted pair copper telephone lines (Negroponte, 1995). Again, applying the Benefits Analysis Map to ADSL in the UK identifies the advantage of wide availability of telephone network infrastructure and good quality video reception at the user end. A with WIRE-Mediaspace use of the return line may be acceptable for student interaction with a live lecture, but may not be of high enough quality to enable a lecturer to deliver from a distance. Again, there is the issue of centralised broadcast with an appropriate level of decentralised interaction and contribution.

Likely costs of ADSL delivery to the user are not available at present. More importantly, the costs and access to ADSL may be prohibitive. Whereas it is straightforward for individuals and institutions to set up World Wide Web servers, use educational networks and even access satellite uplink facilities, there may be limitations in delivery of courses via ADSL. ADSL is not an attractive technology in countries that do not have an extensive telephone network infrastructure.

Into the future

As new technologies develop, the opportunities to combine them for multi-mode delivery open up, thus widening the potential number of users that can receive courses. For example, the combination of satellite and cable networks was implemented in the WIRE-Mediaspace project to extend the reach of the programmes to homes in Finland. Combined satellite and ADSL networks would widen access to users in countries with widely differing network infrastructures.

The potential contribution of VSAT (Very Small Aperture Terminal) technology is worthy of consideration. VSATs such as the TDS4 uplink at the University of Plymouth are satellite transmit systems. As costs of VSATs fall so their potential contribution in an integrated satellite/terrestrial network becomes more important. In particular, VSATs can provide very high bandwidth, two-way communication - the very requirement that has become a stumbling block for several applications discussed above. Again, the potential advantages of multi-mode delivery systems if they include VSAT technology for a high bandwidth return facility will be substantial. A recent contract awarded by the British National Space Centre will enable RATIO and the University of Plymouth to build, test and evaluate VSAT technology in the context of distance learning delivery.

Conclusions

Technologies for distance learning are devloping fast, especially in delivery systems and learning support network infrastructures. In order to achieve the required levels of Quality, Access and Cost that users and providers expect, it is likely that solutions for delivery of distance learning courses will involve an appropriate combination of computer and network technologies. In particular, it seems likely that a combination of satellite and terrestrial networks will be the key factor in the delivery of effective distance learning courses. Whatever the outcomes, professional health care training in the South West of the UK, and ultimately world wide, is set to benefit from the new convergent technologies.

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References

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This paper was first published in the Information Technology in Nursing and Information Management Journal, British Computer Society, Nursing Specialist Group, Volume 9, Issue 6, December 1997.