John Bray

Innovation and the Communications Revolution

A fascinating account of the origins and development, of the technology that has transformed telecommunications and broadcasting and created the Internet.

Telecommunications and the future

This review of innovators and innovation in telecommunications and broadcasting systems has shown how these have evolved from the primitive beginnings of electrical science in the 18th century to the comprehensive, powerful and world wide communication systems of the 21st century, which are now indispensable to the social and business worlds and the processes of government. The technology and system concepts that have been created would appear to provide well for existing communication service needs, both in types of service and by scale, and even to anticipate in some degree future needs.

Pioneers of Television Broadcasting

When one views today’s superb high-quality color television pictures—with the prospect of even higher definition, large-screen receivers offering three-dimensional pictures to come—it is difficult to realize how crude were the early attempts to achieve “viewing at a distance.” It is very doubtful whether even the most optimistic and farsighted of the pioneers had any clear vision of what, in the fullness of time, was to be achieved.

Information Technology and Services

To an increasing extent, social, economic, and political activities in the modern world are becoming dependent on information technology (IT)—the means by which information in the form of data is stored, processed, and accessed. The advances in telecommunications outlined in earlier chapters have removed the barrier of distance and reduced the costs of transmission so that users and data banks can be remote from one another. The microchip has enabled vast amounts of data to be stored, rapidly processed, and accessed at costs that continue to fall. And in the future IT may well have a powerful influence on where people live and work, and on the environment itself by minimizing the need to travel to communicate (Refs. 1, 2, and Chapter 21).

Pioneers of Long-Distance Waveguide Systems

The possibility that electromagnetic (EM) waves, whether as microwaves or light waves, might be propagated over long distances on dielectric rods or in metal tubes with or without a dielectric filling was studied from motives of scientific and mathematical interest, long before applications for long-distance communication seemed either practicable or useful. As long ago as 1897, Lord Rayleigh in the United Kingdom had shown, from certain solutions of Maxwell’s field equations (Chapter 2), that EM waves could propagate freely inside hollow metal tubes provided that the wavelength was appreciably shorter than a cross-sectional dimension of the rod or tube.1 This meant in effect that there was a “cutoff” frequency below which EM waves would not propagate; for rods or tubes of a convenient size, e.g., a few centimeters across, frequencies of many gigahertz were required for free propagation. In the absence of suitable sources and detectors for such frequencies, it was not until the 1930s that pioneering experimental studies of centimeter-wavelength guided waves began to be made in the United States by George C. Southworth of AT&T/Bell Labs.2 (EM waves on wire pairs or coaxials are also “guided,” but without a lower limit of frequency.)

The Inventors of the Transistor and the Microchip

The inventions of the transistor in the 1940s and the planar integrated circuit—the microchip—in the 1960s began a development in electronics that was to have a wide-ranging, profound, and continuing impact on telecommunications, sound and television broadcasting, and computing throughout the world. They enabled electronic equipment to be made more compact, more reliable, and lower in cost and power consumption than was possible using thermionic valves. The microchip in particular enabled circuit operations of far greater complexity to be performed reliably, rapidly, and economically, greatly enhancing the capability of computers to calculate, the service functions available in electronic telephone exchanges, and the quality of color television broadcasting. The transistor and the microchip facilitated the design of larger-capacity land and submarine cable systems and the design of communication satellites. They made possible a vast new range of customer equipment for computing, communicating, and broadcasting; they gave rise to new electronic industries and changed old ones beyond recognition.1

The First Telegraph and Cable Engineers

The first practical system of long-distance telegraphic communication was the semaphore, which used manually movable arms or closable apertures mounted in towers, usually on hilltops and within line-of-sight of one another, to convey messages letter by letter.

The Creators of Information Theory, Pulse-Code Modulation, and Digital Techniques

The better understanding of the nature of information, e.g., as conveyed from a sender to a receiver by telephonic speech, a facsimile picture, or a television program, and the development of theories providing a quantitative approach to design have been vital for progress in the evolution of more efficient telecommunication transmission and broadcasting systems. The initial, and major, steps forward were the work of a few innovative and farsighted individuals in the laboratories of the American Telephone and Telegraph Company in the United States, Standard Telephones and Cables Ltd. in England, and the International Telephone and Telegraph Company in France.

The First Satellite Communication Engineers

The ability of Earth-orbiting satellites to provide, economically and reliably, direct high-quality communication between any two locations on the Earth’s surface, and direct broadcasting coverage over large areas, has expanded enormously the scope and volume of these services.

Creators of the mathematical and scientific foundations

Telecommunications is an exact science that depends heavily on scientific discoveries and advances in mathematics made by a small number of scientists and mathematicians in Europe during the mid-19th century, among whose names those of Volta, Ampere and Ohm, Faraday and Oersted, Maxwell, Hertz, and Heaviside are outstanding.