Only 15 years ago making an international telephone call could be something of an ordeal. The post dial delay of 15 seconds (remember those old mechanical dials?) was followed by concatenated electromechanical switching delays that could add a further 15 seconds or more. Similarly the processing speed of computers and printers meant that you could wait for seconds or minutes for screen fill or print out. How different it is today! Now we get irritated if we do not hear the familiar ring tone immediately we press the last digit on the key pad, or when we have to wait seconds for a PC application to load. The generic problem is having to wait for a period that is too short to do anything else, but long enough to vreak our concentration. Delays of a fraction of a second can disrupt our mental agility and interactive creativity to an alarming degree.

In contrast to our recent past we now have an abundance of bandwidth, storage capacity and processing power, with optical fibre, CDs, and power PCs. Moreover technology promises even higher levels of circuit density and clock speed at insignificant cost. We are thus approaching the realisation of a dream; to access everything, everywhere, anytime, within 3 clicks of a mouse and have screen fill and interaction within a second. For us to enjoy natural, and effective communication with people and machines, in real or virtual worlds, the need is for sensory delays of less than 100ms.

Why should we foster such a dream? The principal reasons are twofold: firstly, we live in an accelerating world where we all have to do more in less time and communication delay limits our creativity and output, and secondly, it can be done! Trying to interact with anything, or anyone, at less than natural human speed soon becomes counter productive and extremely irritating. For anyone who has tried to communicate using a telephone operating over a geo-stationery satellite, which introduces over 300ms of delay, it is obvious. An even more obvious experience is that of trying to access information from a CD ROM, LAN, or the Internet - the Information Super Cart Track! Here delay is endemic due to inappropriate protocols and layers of unnecessary and inefficient software. Even writing a letter, sending e-mail and manipulating simple documents now seems to require a Power PC to get delays down to a few seconds. The reality is that many PC applications waste increasing MBytes of RAM making the front end prettier, and providing unwanted and unused facilities, rather than making the process more effective.

In telecommunications the deregulated market may soon see the concatenation of digital mobile telephones (with an internal codec delay in excess of 120ms), statistical multiplexers, ATM switches, satellite and cable links of numerous uncoordinated suppliers adding undefined transmission delays of random duration. This new regime of unpredictable delays will take us further away from realising another dream; matching man and machine to achieve effective and efficient communication and creativity. Whilst the bandwidth constraints of the radio spectrum offer some excuse for heavyweight coding, the choice of TDMA and very long delay coding processes is curious! But perhaps more dangerous will be the prospect of economic routings chosen in ignorance of the final application. E-mail over GSM, no problem, but speech with a total coding and transmission delay of more than 0.5s will be a disaster on a par with telephone calls over Internet.

For anyone trying to communicate effectively over a narrow-band video conferencing circuit, where the Codec and signal path can introduce delays of over 300ms in the visual image, with a different, and disconnected, delay in the speech circuit - the problem is more immediately obvious. Even with a high degree of practice and familiarity such arrangements are a far from realistic replication of true human presence and communication. At a first meeting it can be almost impossible to communicate and work effectively with such delays. Furthermore, the lack of correct physical size, colour, definition, hi-fi sound emanating from the mouth, eye contact and body language, all detract significantly from the illusion of being there. If you know the people at the distant terminal, then your brain provides some compensation and business can be done. It works - but clearly, it is an illusion, not a real experience.

Experimenting with delay between human hand, eye and ear soon shows our critical dependence on precise co-ordination to achieve simple objectives. Much more than a fraction of a second between hand and eye and we have trouble writing. A mere 200ms between lips and voice, and we are talking to a mannequin. At 300ms we can experience severe co-ordination and confusion. Introduce fixed and/or variable delays between the three senses of sight, sound and touch of 100ms or more and our ability to telecommunicate can be noticeably degraded

It is interesting to note that sticking a pin into the end of our finger results in a message arriving at the brain some 30ms later. This approximates well to the 30 ms period for sound discrimination of the human ear, movement detection by the eye, and a separation distance of 10m at which we have difficulty hearing normal speech and discerning facial expressions. Curiously, it also approximates to the time it takes a photon to travel between London and New York on an optical fibre. So in a telepresence future, a surgeon may wish to reach out and touch a patient in the operating theatre in New York whilst actually being in London. The effective distance between the brain and finger tips will then have doubled from 1 to 2m, and without the synchronisation of sight, sound and touch, it will be impossible to interact in a co-ordinated way.

The only prospect of realising this dream relies on optical fibre to provide a true super information highway with minimal electronic delays, bottlenecks, and bandwidth restrictions. It also requires a new attitude to software, which will have to become efficient, instead of prolific, for the processing and storage of information. We will also have to break out of a mind-set that says bandwidth is expensive. It is time to trade bandwidth, processing power and memory capacity for human effectiveness - this is the most precious commodity.

Just watch children interact with machines and it is immediately apparent that they have an insatiable desire for instant gratification - the shortest response time and best graphics. Looking at professionals you see the same phenomena - a desire to be able to do more, faster. It really is time to start bending machines into humans - engineering a match between our natural abilities and that of technology. All the technology required is available today; we only have to adopt the right mind-set and implement the solutions. In the meantime, I suspect our progress will continue to be frustrated by the delays of networks, computers and software configured for the past!