The aim of the JANUS project is to build a prototype of the telematic network that will be required by the future European Electronic Open University Network. Such an organisation is likely to be based on existing organisations including members of the European Association of Distance Teaching Universities. Thus the network to service such an institution would be a multi-campus Local Area Network (LAN).
The nature of inter-LAN links is such that they are permanently active, with a varying amount of actual traffic over a "base load" of network management traffic. This suggests that the network should be built on a basis of permanent connections (such as leased lines) rather than dial-up links, but where some of the permanent connections are of quite low capacity.
For these reasons and in order to provide genuinely Europe-wide access to this network, even in remote, island and Eastern regions, JANUS will implement a satellite network. After discussing the conclusions of the JANUS market research study in Year 1 with EC and other agencies, JANUS has decided to use existing (but state of the art) satellite systems technology for this, rather than develop a specific technology (as was originally planned). A benefit of this is that the JANUS satellite network will be operational in mid 1993 rather than in late 1994 as originally envisaged.
The satellite network will have a hub station but the pattern of traffic will be "mesh" - that is, any node will be able to communicate with any other node.
The initial JANUS network will have six nodes - one each in Britain, Portugal, Holland and Finland, and two in Greece. Each node will have a satellite Very Small Aperture Terminal (VSAT); installed at it. The JANUS project is under the direction of the UK Open University. The other partners are the European Association of Distance Teaching Universities, Portugal Telecom, Integrated Information Systems of Athens, and Lahti Research and Training Institute at Helsinki University. In 1992, GEC Marconi Communications Systems Ltd provided major technical input.
JANUS has implemented a mixture of satellite and terrestrial networking technologies. There is a core network of six leased 'LanAdvantage' VSAT (Very Small Aperture Terminal) earth stations, all connected via the satellite, with extensions via terrestrial links, including Internet, X.25 ISDN (which allows high quality speech and data transmission) and analogue modem services. An extension into the France Telecom Transpac/Infonet network gives world-wide dial-up access to JANUS services. Access in many countries is nearly completely via local call, for example, in France (via Transpac) and in the UK via BT's DialPlus service. There is also access to the network via commercial Internet suppliers. JANUS VSAT nodes are located in Finland, Greece (Athens and Crete), Holland, Portugal and in the UK.
A spin-off of the project has been the formation of the JANUS User Association which aims to widely disseminate knowledge and know-how in using telematics in education and training, through conferences, demonstrations, and electronic and paper-based newsletters.
In a distance teaching system, most students are remote from the providers of courseware. This requires that the JANUS network "reaches out" to service students, wherever they are, in home, educational institution or the work place. But this must be done without compromising the quality of the user interface. The most natural way to do this is to use the Integrated Service Digital Network (ISDN), and high-speed analog modem technology over the Public Switched Digital Network (PSTN); in locations where ISDN will not soon be available.
Thus each node in JANUS will have "tails" connected to terrestrial networks, including PSDN (the public X.25 services).
Another use for ISDN in JANUS is to provide bandwidth on demand during periods of high use of the network, for example for large multi-media messages or for a real-time audio-graphic teleconference.
Thus JANUS will demonstrate that there is a high degree of complementarity and inter-operability between satellite technology and ISDN.
Work in 1993
In the spring of 1993 JANUS will decide on VSAT service supplier and deploy the VSAT network. Thus by the end of 1993 there will be the first pieces of evidence on the incremental effect of a VSAT network in the education sector.
The other work in 1993 concentrates on:
Development of computer conferencing and electronic mail systems with modern graphical user interface and inter-operating with the existing conferencing and electronic mail systems at partner sites.
Evaluation of the effect of satellite and terrestrial links on partners' activity in the areas of joint materials development, teaching via telematics (mainly computer conferencing and electronic mail) and access to remote databases held at partner sites.
Development of interest in and knowledge of the potential of satellite communications, through the fostering of a JANUS User Group with regional chapters and a series of telematic briefings.
Work on network management and network requirements of future users of the JANUS network.