January 3, 1997. Copyright, 1997, Graphic News. All rights reserved

PHONES THAT TELL YOU WHERE YOU ARE

LONDON, January 3, Graphic News- YouÕre driving miles from home when the kids start screaming that they are hungry; where is the nearest fast-food restaurant? YouÕre a woman, lost on a lonely road late at night and your car breaks down; how do you summon help without unlocking the doors? You have just discovered your car has been stolen; how can you locate it quickly?

Technological wizardry, the brain-child of a Cambridge University physicist, could soon provide an inexpensive and easy answer to all these modern problems.
The GSM Cursor system turns an ordinary mobile phone into a powerful location device, which can pin point the userÕs position to within 50 metres (55 yards).
With almost 60 countries now using GSM Ð the Global System for Mobile Communication Ð the need for value-added services is increasing all the time, and the creation of Cursor is as well timed as it is ingenious.

The inventor, Dr Peter Duffet-Smith of the Mullard Radio Astronomy Observatory, believes Cursor will have a great impact world-wide. The concept has been developed from Dr Duffet-SmithÕs work using radio telescopes and interferometry techniques to pin-point distant galaxies.

With the launch of the first GSM networks in Germany, France, Denmark and the UK in 1993 came the opportunity to apply the principles of radio astronomy to digital cell phones.

When two radio telescopes focus on some distant galaxy, the signals they detect will reach the one that is closer moments before they reach the other.
Because the astronomer knows exactly where his telescopes are, and can measure the time-lag between the detection of the signals, he can calculate where the galaxy is using school-room trigonometry.

With Cursor, the ÔgalaxiesÕ are the existing mobile phone relay-masts which already cover the countryside. One of the Ôradio telescopesÕ is a small base station, the other is your mobile phone.

This time the position of the ÔgalaxiesÕ and first telescope Ð the base station Ð are known. The same simple mathematics can then be used to calculate where your phone Ð and hence you Ð are.

ÔThe technology is very straight forward and the GSM digital phone already has everything we need in it Ð we only have to reprogramme it slightly,Õ Dr Duffet-Smith said.

Cursor can easily be linked to a national network of databases, like an automatic version of Talking Pages. Computers assesses what the mobile phone user wants Ð depending on the number dialed Ð and sends back the relevant data via the relay stations. This could be a street map shown on the phoneÕs display, or a simple set of instructions to guide you to your destination.
Developing Cursor has dominated Dr Duffet-SmithÕs more esoteric quest to plumb the depths of space, but once the project is running smoothly he intends to return to exploring the far reaches of the universe

Source: Cambridge Evening News