COMPUTING resources at Hongkong's tertiary institutions received a shot in the arm last week with the commissioning of new high-speed network links between campus data centres. The new fibre optic-base network was set up to cope with the expected ''rapidly exploding'' rise in data traffic over the Hongkong Academic and Research Network (HARNET) during the next few years. The high-capacity network infrastructure should make way for new areas of multimedia network services between campuses, creating an opening for new teaching and joint research methodology. HARNET was set up in 1986 to let institutions share computing and data resources, but had become hopelessly congested because of the limited capacity of the 4,800 bits per second (bps), according to University and Polytechnic Computer Centre (UPCC) director, Dr Ng Nam. New network facilities are based on the high-speed 1.544 Mbps (million bps) T1 facilities used by Hongkong Telecom in its commercial LANline service. (Telecom, through its Hongkong Telecom Foundation, supported construction of the new facility with a grant of $4 million over three years.) The seven institutions are connected in a ring configuration, which gives the network an ''inherent diversity'', because data traffic can flow in the reverse direction if a break occurs anywhere in the network. ''This is a major upgrade for us,'' said Dr Ng. ''It will make a big difference because the previous links were so congested. ''Sometimes things became so slow that people would be reluctant to use (HARNET).'' HARNET designers are considering upgrading the network's international facilities, which are serviced by a single 64 Kbps (thousand bps) leased circuit which connects to an INTERNET node in America. ''That is where the bottleneck is at the moment,'' Dr Ng said. ''It is in use more than 95 per cent of the time.'' INTERNET links academic institutions throughout the United States and 30 countries. Demand for INTERNET connection, which allows Hongkong's academics and students to access library catalogues and databases world-wide, has greatly increased in the past few years. The UPCC is evaluating a plan to double the capacity of its international link to 128 Kbps, with a decision expected by the middle of the year. HARNET is also investigating how multimedia services could be used on the network as a teaching aid - for example, in holding inter-campus lectures or tutorials via video-conferencing. ''There is no definite plan for multimedia services at the moment, but it is something that we have in the backs of our minds,'' Dr Ng said. ''The additional capacity of the network creates a whole new way of teaching and learning.'' Dr Ng said demand for information services was fairly evenly spread across the various tertiary disciplines - a vastly changed environment compared to a few years ago, when the only interest in networks came from those in the scientific and engineering fields who needed to ''time-share'' on central computer systems. ''Now you find that the arts and humanities are also big users, because now we are talking about accessing information over a network - rather than just accessing computational power over the network,'' said Dr said. Dr Ng said previously the UPCC had looked at networking issues as a way for tertiary institutions to share high-value centrally-located processors. With the cost of computers having fallen so dramatically in the past 15 years - and their performance having improved so radically - the cost effectiveness of sharing central facilities has diminished. Cheap access to computers means the primary use of academic networks becomes the exchange of information - such as by electronic mail or via bulletin board services - and access to library data bases.