From next week's American Association for the Advancement of Science meeting in San Francisco.

The internet has changed the way we communicate. John Connolly believes the access grid could change the way we live.

As the clich¨¦ goes: "The network changes everything." The internet has revolutionised interpersonal communication and retail commerce - through email, the worldwide web and the even more pervasive dotcoms. Now, an application has arisen on the internet that promises to do the same for education and teleconferencing.

The new application goes by the name of the access grid and it is a low-cost interactive apparatus through which one network site can interact (in both audio and video) with up to 50 other sites. This allows a teacher or lecturer to expand his or her audience by a factor of 50 or more. This has the potential to change the nature of remote education and the ultimate function of a school or university.

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The access grid is a concept invented by scientists at the Argonne National Laboratory, a research centre supported by the United States department of energy at a site just outside Chicago. A small group of network and computer scientists, under the leadership of network expert Rick Stevens, has developed a suite of software codes that allows anyone with three personal computers and three digital projectors to set up a digital teleconferencing centre. The three computers are used to control the audio stream, the video stream and coordinate the projectors. The signals are combined and compressed into a set of binary digits that usually requires a network bandwidth of about one megabit per second per stream. The audio/video streams are projected on a floor-to-ceiling, wall-sized screen. The result looks like a huge computer monitor speckled with windows, each representing a single remote site.

If the access grid node is connected to what is called a DS3 line (45 megabits per second), typical for a US research university, then several dozen streams can be handled simultaneously. If one is fortunate enough to have more bandwidth, more streams can be sustained. An analogy may make this clearer. If an ordinary network connection is like a telephone conversation, then an access grid connection is like a conference call, with the added advantage that one can see who is speaking, with his or her extra "non-verbal" signals exposed (which some experts say is up to 75 per cent of personal communication).

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Given such a configuration, a lecturer at the University of Kentucky could give classes and interact in real time with students in Illinois, Massachusetts, Virginia, New Mexico, Utah, Kansas and North Dakota, for example. This is particularly useful for an audience in the remote "hinterlands" of the US and indeed the world.

If one is a student or researcher at the University of North Dakota, one sits in a far off part of the country that is expensive in time and money to leave.

The effect of this configuration is, according to many observers, "the next best thing to being there". One can see and talk to many groups of people at remote locations. Because this is a video as well, one can also see to whom one is speaking and who is speaking to you.

The access grid started a little over a year ago with a handful of nodes talking to each other. Now it includes about 50 institutions (mainly US universities and research institutions). This number is expected to grow at an exponential pace, much as the original internet did in its embryonic days in the 1980s.

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Subject to the availability of network and bandwidth, the first nodes outside the US will be installed this year. The concept has been proven in a demonstration mode in Japan and Russia. Other nodes are planned in Europe and Asia, as well as in Canada, the Middle East and Australia. In November, this year's annual supercomputer conference will broadcast many of its sessions through the access grid and will originate many of its sessions at the remote sites outside the US. The greatest difficulty is coordinating lecturers and audiences who may be as many as 12 time zones apart. Two sites that according to Stevens are being considered as nodes and that will not be much affected by the time difference, are the Antarctic research station at the South Pole and the new International Space Station.

It does not take much imagination to understand how the world will change when access grid nodes are as ubiquitous as ordinary internet nodes. When one can interact with any group in a spontaneous and user-friendly fashion, then interhuman communication will fundamentally change its character. Could we dare to believe that this technology could reduce congestion at airports as more and more management and planning meetings are held on the grid rather than face to face?

Will the students of a mid-21st century university be scattered over the globe? Inversely, will the student seek out the lectures of the world's best expert rather than that of a local professor? Will the university then decide that it no longer needs to be "universal" but can afford to be a "niche player"? One can imagine that the University of Kentucky could be a specialist in a narrow field such as theoretical quantum theory, but with no classes in classics or the humanities, because the best people in those areas are network-accessible at Harvard and Oxford. One can indeed imagine, but prediction is a perilous business in the rapidly changing technological environment. Everyone in the networking and education fields will be eagerly awaiting these developments.

John W. D. Connolly, director of the Centre for Computational Sciences, University of Kentucky, Lexington, Kentucky, US.

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A good reference to learn more about the access grid is
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