In 1989, Edith Cowan University applied for and was granted $550,000 through the DEET National Priorities Reserve Funding scheme to install a video conferencing network. Work commenced in January 1990 on final planning and technical design with Telecom Western Australia. Contracts were finally signed later that year and the network was commissioned in July 1991 for a first stage of operation. One year later, and some 500 hours of transmission time later, the network is proving to be a major success with the very real possibility of needing to enlarge its transmission capacity during 1993. The original plan was to create a narrowcast network linking the University's four major campuses. However its network architecture, using Telecom's Television Operating Centre in Perth as its hub, has enabled the University to access other networks and it has played a major role in two state projects bringing live interactive video instruction to non metropolitan areas of the State. Utilising its fibre optic links, both full bandwidth analogue signals and digitally compressed video signals have been sent by satellite to learning centres, colleges and Aboriginal communities in outlying areas. This paper presents an overall view from planning stage to operational management, highlighting achievements and detailing areas which will demand further exploration.
The video network currently operating at Edith Cowan University was conceived in 1986, but it was not until December 1989 that it attracted funding through the DEET National Priorities Reserve Funding Scheme when a sum of $550,000 was allocated to install the system.
Two previous scenarios had suggested the use of Telecom's leased bearers along coaxial cable, or alternatively a University owned microwave network linking the three major metropolitan campuses with a leased bearer to connect the fourth campus at Bunbury.
However, early in 1989 Telecom engineers suggested the use of optical fibre cable, a system previously ruled out because there had been no predictions that optical fibre would have been available at that time. Optical fibre enabled Edith Cowan to develop a network that quite specifically would meet its requirements.
The need for a video network stemmed from the multi campus nature of the University. It was becoming increasingly common for some staff to find themselves lecturing on more than one campus, often giving the same lecture to a new group of students. This resulted in excessive travelling commitments particularly to Bunbury which involved approximately an overall five hours of driving time. It was also difficult to offer specialist courses on some of the smaller campuses where intake and class numbers were too small to make running the course viable. This was particularly so at Bunbury.
Added to the problems faced by lecturers, administrative meetings in multi-campus situations are notorious for eating up time, and it was generally felt that the network would alleviate some of the problems faced by the administration.
That whilst the network operated on a narrow cast system, nevertheless there would be a need for flexibility in going outside the network to other networks. This might be in a broadcast mode via the Golden West Network, OTC or AUSSAT.
However, Churchlands to Bunbury, Joondalup to Bunbury would not currently be possible. It would be desirable if the system could be multiplexed: that is for multiple signals to be sent down the fibre. This is technically possible, but the equipment is both very new and expensive. It is expected that this possibility will become technically and financially feasible in one to two years.
Entry to digital compression networks can be achieved through a codec gateway in TOC Perth via a Rembrandt II codec. If there is a need to gain access to Picturetel systems, because, for instance, of the failure of H261 to achieve compatibility, the University will either interface a Picturetel codec within its network or negotiate with Telecom to provide a Picturetel gateway in its own system architecture.
Figure 1: ECUNET configurations (After B G Pilcher, 16/3/92)
The ECUNET architecture allows not only the narrowcast capability between the four university campuses but also to a point to multipoint mode via the Golden West Network in Bunbury. Currently, uplinking is to a 12 watt transponder for the WESTLINK project, or for the WA Higher Learning Networks project, and for live broadcasts via the RCTS EDTV channel, broadcasting during the four school terms.
A television transmission to Noonkenbah Aboriginal Community. One way video and two way audio from Mount Lawley campus studio. Wives and children from the community who were in Perth to attend a conference spoke with members of the community in Noonkenbah.
A live broadcast via a 12 watt transponder to the rest of the state of a lecture given by Professor Odille Challe from the University of Paris, Dauphine from the Mount Lawley Campus lecture theatre, which incorporated live pictures of mini-tel, the French telematics system which were accessed and operated from the lecture theatre by Professor Challe.
One hundred and sixty four hours of narrow cast via the Westlink projects 12 watt transponder to Broome, Derby, Kununurra, Esperance, Narrogin, Geraldton one way video two way audio, and 50 hours of compressed transmission to Kununurra. Topics included computer studies, nursing, professional development.
A video conference linking 33 Aboriginal communities in Western Australia with Aboriginal groups and individuals from the Mount Lawley Conference Room - Perth.
The issue is not to define the transmission medium; the issue is to define the learning objective. You have to know the style, the communication capacity and skills of the instructor. You have to know who the students are, what they already know and their learning styles. You have to know the nature of the message, its information intensiveness and the learning objective. Once you know all these you can figure out what kind of channel you need. Until you know all those things you are going about it the wrong way if you start with the channel and work back.
Thus, tests carried out at CSU Chico, demonstrated that compressed video is not adequate for a generation of students who have grown up with broadcast quality images. On the other hand, in certain circumstances where broadcast quality image may not be achievable, a compressed signal may be better than no video signal at all.
Nursing - Particularly professional development coursesWe believe also that studies such as languages and art would all be suited to the methodology. Added to this administrative and other uses have included:
Business Studies - Accounting and Law
Education - Particularly professional development short courses
Computer Studies - Linked also to interactive computer operation and dialogue
Heads of Departments and Faculty meetingsHowever, certain factors have emerged which demand further study and observation. Quality of reception is an important factor, and one which cannot and should not be dismissed lightly on the grounds of cost. ECUNET uses optical fibre so that it could proceed with its already existing campus based analogue CCTV systems. Quality of signal was always the primary concern of those planning the network on the grounds that if lectures were to be transmitted at the shortest distance of 15 kms, a high degree of transparency had to be present. Students should not be affected by 'noise' as an added factor of difference. It was felt that until digitised signals became equivalent to broadcast standard, they would not be used between campuses. However, when contact had to be made outside ECUNET to areas in the state that had codecs, then the system had to be capable of accessing them.
Down loading video programs
Transmission of film between campuses allowing for use in non violation of copyright laws.
The choice made, seems to have been endorsed by Terry Curtis whose Department of Communication Design at California State University at Chicago ran tests last year and this year to test the acceptability of compressed video conferencing. The tests demonstrated that at school level, compressed video is not adequate for a generation of students who have grown up with broadcast quality images As Curtis comments:
High school students and even College students are very uncomfortable with compressed video....Two way full motion video with low intensity information is wasteful. But if you have very information - intensive objectives, then anything less than two way full motion video is inadequate.It would seem that in some networks developed in Australian Tertiary Institutions, an obsessive view has been taken that cost is the only factor to be taken into account, and that 128 kbs is quite sufficient to get the message across. I have very serious doubts that this is a valid argument. What should be far more important is educational quality and not 'how cheap can we make it from point A to point B'.
There is perhaps a difference to be drawn between what we at Edith Cowan University have called 'tale-lecturing' and 'video conferencing'. For the former, quality of signal is a very important factor. For video conferencing which encompasses many administrative and small group functions, quality of signal may not be a paramount factor. Thus, if I want to talk to two heads of departments, I may find it acceptable to use a degraded signal in order to reduce transmission costs.
Similarly, there are times when one way video with two way audio is an effective mode of communication. This is particularly so when the purpose is to get the message to several dispersed groups - often called a point to multi point transmission. This method has been used very effectively in Western Australia to teach groups in country centres. One particular series has taught computer studies to five centres simultaneously, from Kununurra in the far North of the State to Narrogin in the South West. Use was made of a 12 watt transponder, and our full bandwidth signal was uplinked from GWN's earth station at Bunbury, meaning that all centres received a quality signal very necessary when explaining the intricacies of a computer screen! It is difficult at this time to provide an accurate estimate of the cost saving and indeed the time scale that would have been involved if our computer expert had been providing the on site teaching for each centre. If it had been possible it would have cost many thousands of dollars.
Another question that needs examination is the organisation and management of a network. It would seem from our own experience that once a network proves accessible and successful, there is an exponential growth of usage. Much care and attention was given to the location of network sites on each campus. Currently sixteen sites are fitted out on the four University campuses, providing alternative and varied locations. These range from a large lecture theatre, a small lecture room, and a conference room on each site, together with specialist areas like TV studios, a Graduate Management Centre and a small video conference room totally dedicated to the network. Programming becomes a vital component in management, particularly when locations are not dedicated to the network. Outside links also have to be booked with Telecom or any other agency involved in the conference. Two staff members ran the network at ECU with assistance from other Media Services staff on campuses. However, it is acknowledged that staff levels have to be kept at a minimum which has led to plans for ease of operation and remote servicing wherever possible.
Following London University's 'LIVENET' a user group was formed from representatives from each Faculty in the University. The purpose of this group was to take responsibility for University access and future growth, determining questions that might arise as use expanded. Media Services would be left in operational control only.
Other questions that will soon have to be answered relate to codec compatibility, multiplexing, and sound quality in certain modes of operation. Currently two makes of codec have been selected by Universities and TAFE colleges neither of which can 'talk' to the other. The advent of the international standard H261 will reputedly clear this problem, although it is by no means certain that full compatibility will be achieved. In the meantime a national network is at risk because purchase commitments have been made on insufficient evidence that equipment will perform in the manner in which it is meant to perform.
Multiplexing means transmitting more than one video signal utilising an original source. New technology developed by CLI, the spectrum saver broadcast video system using compressed digital video (CDV) will allow up to a dozen or more channels to be broadcast over a satellite transponder. The system currently being installed at the Monterey Institute of Technology in Mexico requires only 2.3 MHz per signal of the 36 MHz bandwidth available on the satellite transponder, and delivers excellent pictures. Whilst this may not be a preferred solution for Australian networks, nevertheless it does mean that there are several alternatives already available which should be examined before commitments are made to systems requiring multiple signal transmissions.
|Author: Associate Professor Michael Grant is Head, Media Services Division at Edith Cowan University. He is currently a board member of Radio Station 6NR, on the Advisory Board of the School of Communications and Cultural Studies at Curtin University, a member of the Media Advisory Board, Academy of Performing Arts. He is also a member of the Management Board of the Festival of Perth and Chairman of the Friends of the Festival of Perth. He has over the past two years directed two DEET funded National Priorities l Reserve Funding projects - the Cowan Video Conferencing Network and the Western Australian Distance Education Consortium Japanese Language Interactive Videodisc project. He can be contacted at the Media Services Division, Edith Cowan University, Pearson Street, Churchlands 6018, Western Australia.
Please cite as: Grant, M. (1992). Ecunet, Edith Cowan University's video conferencing network: Two years on. In J. G. Hedberg and J. Steele (eds), Educational Technology for the Clever Country: Selected papers from EdTech'92, 1-9. Canberra: AJET Publications. http://www.aset.org.au/confs/edtech92/grant.html