The use of light, rather than electronics, could one day lead to much cheaper phone calls, reports Danielle Barron
One of the benefits of modern living is picking up the telephone and instantly connecting to someone anywhere in the world. Who appreciates the genius of this, however, especially when those annoying phone bills arrive?
Physicists at University College Cork are now working on a way of making the remarkable technology behind telephones even more amazing, using light instead of electricity to transmit our chatter. The work involves developing a leading-edge technology called photonics, which aims to revolutionise how the telecommunications network operates.
Although photonics is increasingly being used in computing, security and other applications, not everyone is aware of it.
"Everybody's heard of electronics. Very few people have heard of photonics," admits Prof David Cotter, head of the Photonics Systems Group (PSG) at the Tyndall National Institute at UCC.
However, photonics are everywhere, adds Cotter. "Virtually all of the telecommunications companies use optical fibres, and so does the internet," he says.
Photonics is the use of light, instead of electronics (which uses electrical signals) to transmit and process information. While metal wires are used in electronics, optical fibres are used as the transmission medium in photonics, explains Cotter. The problem with photonics is that it is much less developed than electronics.
"It is still an experimental technology," says Cotter. Yet the field is experiencing major growth. The current world market for photonics is estimated at €150 billion and is projected to increase to €500 billion by 2013.
Ireland still relies heavily on electronics, according to Cotter. "At the moment, if you have broadband installed, it comes over through copper wires," he says. However, in other parts of the world, especially in Japan, optical fibres are now used to carry broadband to people's homes. Cotter says his team are looking even further beyond this to the next generation of optical fibres.
"We are developing a new network architecture that could radically bring down the cost of telecommunications," he says. Currently, "there is a lot of very expensive equipment needed to receive and process signals and to send them through the call network".
Cotter's team are working on an alternative that will allow phone calls to bypass local exchanges and be transmitted directly to the core network.
"If you are living in Waterford, for example, and make a phone call, it would not go to the local exchange in Waterford but go straight to Dublin instead," Cotter says.
His colleagues have now designed laboratory experiments that show how such an approach is possible.
"There are bench-top experiments we can carry out that demonstrate the physical feasibility of this technology," Cotter explains. These experiments use the same essential components required in an actual telephone network, including 100km of optical fibre wound around a drum.
Such an approach would mean that companies could strip out the expensive equipment at local exchanges, according to Cotter. Potentially, this could lead to massive savings for telecommunications companies.
"British Telecom has calculated that if this approach was used in the UK it could save some £12 billion (€17.6 billion) in capital expenditure. Even more interestingly, £1.5 billion (€2.2 billion) could be saved in operational expenses," he says.
The adoption of this new technology may depend on it becoming more affordable.
"In relation to electronics, it is very expensive," Cotter says. Therefore, a fundamental objective of the research carried out by PSG is to reduce the cost of photonics.
The group is also working on ways to improve the efficiency of the optical fibres so that the number used can be reduced. One method being tested is wavelength diverse multiplexing, using the different colours of light, each carrying its own signal, which enables more information to be transmitted. "It means signals for about 1,000 customers can be carried on just one fibre," says Cotter."