THE BIRTH OF OPTICAL FIBRE COMMUNICATIONS: A VERY BRITISH STORY By Stewart Ash, Stuart Barnes, Phil Black, Bill Burns, Chris Swan
Bill Shankly, the late manager of Liverpool Football Club, is often misquoted. What he actually said was ‘Some people believe football is a matter of life and death, I am very disappointed with that attitude. I can assure you it is much, much more important than that.’ For many English football supporters, 30 July 1966, when Geoff Hurst scored a hat-trick at Wembley and England won the World Cup, was just such a visceral moment. However, in the world of telecommunications, July 1966 should be marked for a far more globally significant reason. It was then that two young British engineers, Charles Kuen Kao and George Alfred Hockham, published a paper that would go down in history as the beginning of the optical fibre revolution that transformed digital communications. After the Second World War, Bell Labs began working on combining telephony with video. By the mid-1950s they had produced an early prototype video phone, leading to public demonstrations of the AT&T ‘Picturephone’, including a transcontinental link between Disneyland (Los Ange84
les) and the World’s Fair in New York on 20 April 1964. This led to a belief that, in the future, everyone would want a personal video phone. However, this would require much higher capacity per circuit than the existing copper wirebased telephone networks, carrying 3kHz voice channels, could provide. Multiplex over coaxial cables could carry many voice channels, and digital transmission was being developed. Coaxial systems could transmit 140Mbit/s (the equivalent of 200 x 64kbit/s simultaneous phone calls) but the signal had to be regenerated every 2km.
North Woolwich factory and became a Standard Telephones & Cables (STC) employee in 1925, when the International Telephone & Telegraph Corporation (ITT) acquired the site. After the Second World War, Reeves went to work for STC’s research division, Standard Telecommunication Laboratories (STL), established in Enfield, North London in 1946 and moving to a new facility in Harlow in 1959.
Converting analogue signals into digital information was a British invention. In 1938, the technique of sampling analogue signals and converting them into a digital code was Figure 1: Standard Telecommunication Laboraconceived and patented as tories, Harlow, Essex Pulse Code Modulation (PCM) The Second World War had drivby Alec Harley Reeves. Howeven the development of microer, the required cirwave technology for radar, then cuitry was complex and was not in peace time, thanks largely to economically viable until transisthe work of Professor Harold E M tors became commercially availBarlow (1899-1989) at University able in 1953. Reeves had joined College London (UCL), the techWestern Electric Ltd in 1923 at its nology was adopted for telecom-
SUBBTEL FORUM | Issue 149