The problem of "tele-multimedia" is the amount of data that has to be sent around. Sending text via a modem on a telephone line is straightforward because the files are small. So is a simple animation or still image. Sending a file containing high-quality sounds is considerably more difficult: it can take more than five minutes to send a half-minute audio clip. And sending TV-quality video takes forever. More than two hours for one minute ... Tele-multimedia requires the designer to use some restraint.
Probably the most widely used form of tele-multimedia is the World Wide Web. "By its very nature, the WWW, with its combination of text and graphics, is multimedia," says Henry Ritson of UUNET Pipex. "Until the development of the WWW, the Internet was nearly all text-only."
Although the depth of multimedia and interactivity on the Web is still generally low, it is developing rapidly as animation and sounds are added to many Web sites. "At the moment, Web pages can be enhanced with logos spinning round and a small clip from the chairman's speech," says Mr Ritson. "But in four years' time we will probably look back and laugh at how basic it all is."
Companies are wondering how they should best use the Web but, according to Andy Mitchell, an account director at Digital Communications Ogilvy & Mather, they have a long way to go. "Most people's experience of the WWW is crushing disillusionment with the mediocre stuff in 2-D they see there. Many `good' sites look like they have been created by Sylvester Stallone - lots of flash and bang but no story. What companies need to create are sites with true meaning and benefits for the visitor."
This, given the current technical restraints, is difficult. "To make an audience come to your site you can use a lot of interactivity and a lot of multimedia," Mr Ritson says. "The downside is the more you put on, the slower it will take to download. So you design the page to make sensible use of the resources."
Mr Mitchell believes things will soon change. "Within the next five years, the convergence of technology will deliver really high bandwidth multimedia to the public in ways that are already familiar to them. For example, a TV may be linked to a set-top box, which is a sophisticated computer connected into a high-speed digital cable system. Customers will not care about that; they will just notice more information and services available on their television sets."
There are ways round the problem, even today. On Demand Information supplies training and other material to customers over digital ISDN lines, which send data at roughly five times the speed of today's fastest modems. With customers connecting straight into On Demand's own computers, they get very fast throughput.
"This means multimedia applications are not a problem," says Peter Jones, managing director of the company's applications division. "Most of our applications use images, animation, text and sound. These can all be compressed well and sent over the lines." Video still causes indigestion, so On Demand will load clips that might be useful directly on to a customer's computer."
Even using basic technology and a bit of inspiration, it is amazing what you can do with tele-multimedia. Compuserve's Worlds Away is an online chat system that allows users to adopt personalities through avatars, surrogate graphic characters which appear on screen. As people "talk" (by typing on their keyboards) words appear in speech bubbles. In the Worlds Away city there are hundreds of rooms where you can look up information and meet people. While there are only 80 avatars, each has several poses and changes profile as it turns around. These images are sent out on CD- Rom. Dedicated Worlds Away users can upload their own images to be used as their avatar's head.
There is no doubt we will get more and more used to interactive tele- multimedia delivered to our homes and businesses. At present, the technology lags behind users' demands, but it will surely catch up.