1. Background
Distance Education system in our country has come of age and so also is the use of multi-media instructional packages in distance education. Nevertheless, the role of electronic media to the production of audio and video taped lessons for use during counselling sessions at the study centres. Broadcasting of these taped programmes has also been going on through select stations of All India Radio and the national network of Doordarshan as a back-up to the non-broadcast mode of distribution at the study centres.
While efforts are underway by all most all the distance education institutions in the country—especially the open universities—to strengthen the media components, the following short comings, however, continue to plague the system on account of which radical remedial measures are called for:
- The electronic media inputs, such as they are, continue to be viewed upon only as supplementary components, with the print being the all-inclusive master medium.
- The audio/video taped programmes are essentially one-way communication and no element of interactivity can possibly be built into them. The only live interaction possible at present is at the counselling sessions, but the media components themselves cannot be vested with the property of interactivity so long as we confine their use to audio/video tapes.
It is in the context of the second mentioned shortcoming above that new forms of electronic media like teleconferencing become relevant for distance education.
2. Teleconferencing: Different Types
The word 'teleconferencing' can be taken to mean interactive electronic communication among people located at two or more different places. In the context of distance education, teleconferencing provides live interaction through electronic means among learner groups/ teachers/distance education functionaries located at different places. Depending on the nature and extent of interactivity desired and the sophistication of technology employed, teleconferencing systems are classified as follows:
- Computer teleconferencing
- Audio teleconferencing
- Audio-graphic teleconferencing
- Audio plus slow-scan TV teleconferencing
- One-way video and two-way audio teleconferencing
- Two-way video teleconferencing.
Computer teleconferencing is a situation in which only the computer terminals located at various participating locations interact with each other by two-way exchange of computer data in real time. Computer teleconferences operating via dedicated satellite links are becoming increasingly common the world over for mostly business and governmental applications. Audio teleconferencing, which is the topic of the present paper, provides for live exchange of voice messages among the participants at different locations either through the public telephone network or dedicated microwave/satellite links. Audiographic and Audio plus slow-scan TV teleconferences are advanced variations of Audio teleconferencing in which computer generated data and graphics as well as still pictures shot by a video camera can also be exchange can also be exchanged among the locations along with voices.
Two-way video teleconferencing is the most sophisticated of all which enables two way exchange of the participants' images as well as voices. It comes closest to a face-to-face conference. As transmission of video information in real time requires wide bandwidths. it becomes the costliest form of teleconferencing as well. A less costly alternative to a two-way video conferencing is the "one-way video and two-way audio" kind of conferencing wherein only the main location (the 'teaching end' in a typical distance education application) will have the facility to send video information to all other participating locations. The other participating locations ('learning ends') can receive this video information along with audio, but they in turn can only send audio from their respective locations to the teaching end. Experiments of this kind were recently conducted by several institutions in our country in collaboration with the Indian Space Research Organisation (ISRO).
3. Audio Teleconferencing: System Description
Out of the different teleconferencing types described above, two-way video conferencing system will be too costly a proposition in the context of distance education. Even 'one-way video and two-way audio' systems too cannot be of much avail for reasons of cost and the preparatory time involved in the process. An audio teleconferencing system, on the contrary, combines in itself the simplicity and flexibility, inherent in the audio media while offering the advantage of interactivity which conventional audio/video programmes lack. It is also comparatively economical for regular use on a large scale.
The technical system of a typical audio teleconference installation primarily consists of an 'audio bridge'. The audio bridge is an electronic device (somewhat similar to an EPABX board) on which the requisite number of telephone lines terminate. Telephone calls can either be received at or sent out from the bridge and the calls can all be combined such that the callers at different places can converse with each other simultaneously as if in a conference.
There can be as many participants in such an audio conference as there are telephone lines terminated on the bridge. Bridges with a capacity of upto 72 telephone terminals are commercially available. This is the simplest type of audio teleconferencing in which only a bridge of appropriate capacity needs to be installed and no special equipment are required at the participants' premises except the standard telephone set. For better convenience, however, the telephone sets can be replaced by speaker-phone systems so that the participants can talk and listen in a hands-free manner. It is also possible to add a string of external microphones to the speakerphone at each of the participating locations so that a group, rather than a single individual, can participate from each location. Other technical embelishments that can be incorporated are:
- acoustically treated conference rooms at the concerned locations. They help to improve the clarity of voices and their intelligibility. They also help in cutting out extraneous noises and annoying disturbances.
- dedicated telecommunication links in place of normal telephone lines. The normal telephone conversation takes place in the so called half-duplex mode, that is, the same pair or lines are used to talk as well as listen. Half-duplex circuitry causes noise build-up on conferencing systems especially when many locations are involved. This problem is got over in dedicated links employing full-duplex mode with separate channels for talking and listening. The full-duplex mode offers the most 'natural' kind of interactivity.
4. Audio Teleconferencing System of IGNOU
The Indira Gandhi National Open University has recently installed an audio teleconferencing system in order to network the university's main campus at Maidan Garhi, Delhi with its 16 Regional Centres located in different cities all over the country, and three state open Universities viz. BRAOU, YCMOU and KOU. This is the first audio teleconferencing system of its kind in the country and is established in technical collaboration with the Commonwealth of Learning, Canada. The
specific purposes which this system is expected to serve are as follows:
- Periodical conferences among the state open universities, regional centres and the IGNOU's top management for discussing policy matters of mutual concern.
- Exchange of important administrative information such as latest position of student admissions, changes in examination schedules, receipt of course materials, etc.
- Organising expert counselling sessions at a distance, with the concerned experts located at the head quarters and the student groups assembled at the regional centre offices/state open universities. Such expert counselling can form an important supplement to the tutorial counselling held routinely at the study centres.
- Providing periodical guidance to students in academic as well as non-academic matters concerning their study, choice of courses, career prospects, job opportunities etc. This kind of guidance can go a long way in promoting a sense of belonging among the student community and reducing the drop-out rate.
The audio bridge consisting of 24 ports (that is, having a capacity of handling 24 telephone lines) is installed at the Maidan Garhi campus for IGNOU. At each of the participating locations (Maidan Garhi campus + 3 state open universities + 16 regional centres), an 'audio conference unit' consisting of inbuilt microphone and speaker, six external microphones connected in tandem, and an external speaker is provided. The audio conference unit is interfaced to existing telephone line at each of the locations in such a manner that easy switching of the line from telephone set to conference unit and vice-versa is possible.
At the appointed time, the participating locations are expected to call into the bridge by making STD telephone calls from their respective places on particular telephone numbers earmarked for them. The operator at the bridge in Maidan Garhi receives these calls and puts them on 'hold' till all the expected participants have called in. Once every body, has called in, the operator initiates the 'conference mode', and the conference begins. This kind of audio teleconferencing in which the participants at different locations call into the bridge at the appointed time is known as 'meet-me' kind of teleconferencing. Alternatively, there can be a 'dial-up' conferencing, meaning the operator at the bridge initiates the calls by dialing from the bridge to the participating locations one by one, and finally initiating the conference. When the participating locations are more in number (say more than five or so) 'dial-up' type of conferencing consumes a lot of time in setting up, and so is not preferred.
5. Problems and Prospects
As audio teleconferencing system is new to the country, it was decided to subject the system to experimental use to begin with, so that logistical problems involved in operating the system and its potential applications are fully grasped before commissioning it for regular use. The following points, though based on limited experience of the past few months, are worth deliberating in this connection:
- The system, as configured now, is critically dependent on the state of the public telephone system. The quality and reliability of STD lines in our country being what they are, the audio teleconferencing system becomes highly vulnerable to inconsistent voice quality among the participating locations and frequent disconnections of one or the other party during the conference period. As a typical conference ranges from half-an-hour to one hour at a time, the probability of such failures and disturbances is quite high especially when the number of participating locations is large.
- To circumvent the above problem, hooking the system on to dedicated lines in the full-duplex mode seems imperative. However, dedicated lines-whether they be land-based or satellite links-are leased on an annual tariff basis and not on the basis of actual usage. Therefore, while economical for wholesale use, they are prohibitively costly if the need is only for a few hours in a month.
- Assuming that the system is continued on public telephone lines, there can be no denying the fact that the audio teleconferencing mode works out very economical when compared to either face-to-face conferences or other modes of teleconferencing. It is estimated that the operational cost of a one hour audio conference involving all the 16 regional centres, 3 state open universities and IGNOU headquarters at Maidan Garhi works out to Rs.26,000 on a normal weekday, and Rs.13,000 on a Sunday/ national holiday.
- In the interest of economy as well as better interactivity and effective communication, it is advisable to limit the number of participating locations to about five at a time, unless otherwise essential.
- Formatting of the conference sessions should be so designed as to permit frequent aural responses from the participating locations so as to ensure their active presence and participation in the conference.
- Should there be a lecture format followed by question /answer session, it is best to restrict the lecture part to abut five minutes or so and go into the discussion mode as quickly as possible. Prolonged lecture without permitting active response from the other locations would not be a suitable strategy for the teleconferencing situation.
- Absence of visual clues, body language, etc. are to be taken into account for proper communication flow in an audio teleconferencing. For these and other reasons, tight preplanning, clear-cut agenda and active aural responses from all participants would go a longway in ensuring a successful teleconference session.
6. Conclusion
Audio teleconferencing offers a cost-effective means of introducing interactivity into the instructional methodology of distance education institutions. To the extent that interactivity element in today's distance education requires the physical presence of the teacher and the taught at the counselling sessions, it can be said that, to this extent, distant education system is yet to break away from the shackles of the traditional system. Interactivity at a distance, which is what the new media like teleconferencing can offer, merit serious consideration in this regard so that a purer and more refined form of distance education may evolve in future.
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