Video: Claude Shannon: Father of the
Information Age . Co-produced by Cal-(IT)² and UCSD-TV, based on
the Shannon Symposium sponsored by Cal-(IT)² and UCSD's Jacobs School of
Engineering, February 2002.
It is difficult to overstate the importance of Claude Shannon's
contributions to the field of communications. In a landmark 1948 paper,
Shannon laid out the basic principles underlying digital communications
and storage, revolutionizing the way that engineers approached the
subject. He paved the way for the powerful codes now used in
telephony, wireless communications, satellite communications, deep space
communications, and storage devices such as CD players and hard drives;
and he laid the groundwork for compression algorithms used for audio and
Many concepts that seem obvious today were first introduced in his
paper, "A Mathematical Theory of Communication," published in two parts
in the Bell System Technical Journal. The use of the term "bit" as a
unit of information first appeared in this paper. In an age in which
communication took place with continuous, analog waveforms, it was a
startling notion that information traveling across any communications
system could be defined mathematically as some quantity of binary
symbols. It was entirely new that information of any kind-- whether for
use on a telegraph, telephone, radio, or television-- could be
decomposed into zeros and ones, encoded, transmitted, and decoded at the
That was groundbreaking, but it was only one component of his theory.
He went on to present the concept of the maximum rate of transmission on
a channel-- the capacity or "Shannon limit"-- which provides the
benchmark against which all codes and modulations are measured. He
invented adding redundancy to a transmitted signal in order to enable
correcting for transmission errors at the receiving end. He provided
the foundation of data compression, years ahead of any widespread
implementations of digital communications or storage.
In this one paper, Shannon founded the field of information theory.
In a world in which no one knew the concept of a bit, asking the
question, "How many bits per second can be transmitted a channel?" and
doing nothing more would have been momentous. Shannon did this and
proceeded to clearly state the answer, prove it, and begin to show how
to design systems that achieve the limit. He presented a clear picture
of the whole field of information theory, all at once.
Shannon's theory was an immediate success with communications engineers
and stimulated the technology which led to today's Information Age.
Error-correcting codes and data compression are used in virtually every
form of electronic communications.
Shannon published many more provocative and influential articles in a
variety of disciplines. His master's thesis, "A Symbolic Analysis of
Relay and Switching Circuits," used Boolean algebra to establish the
theoretical underpinnings of the field of digital logic. This work has
broad significance because digital circuits are fundamental to the
operation of modern computers and telecommunications systems.
He also is now generally credited with transforming cryptography
from an art to a science, with his 1949 paper entitled "Communication
Theory of Secrecy Systems".
was born in Petoskey, Michigan, on April 30, 1916. He graduated from the
University of Michigan in 1936 with bachelor's degrees in mathematics
and electrical engineering. In 1940 he earned both a master's degree in
electrical engineering and a Ph.D. in mathematics from the Massachusetts
Institute of Technology (MIT).
Shannon joined the mathematics department at Bell Labs in 1941 and
remained affiliated with the Labs until 1972. He became a visiting
professor at MIT in 1956, a permanent member of the faculty in 1958, and
a professor emeritus in 1978.
In the 1990's, he developed Alzheimer's disease, and slowly withdrew
from public life. He was unable to attend a statue dedication in his
hometown of Gaylord, Michigan in 2000, and he died in 2001, at the age
The Information Society of the IEEE established the Shannon Award in
1974, in honor of lifetime achievements in the field of Information
Theory. The winner of the Shannon Award gives a lecture at the
International Symposium of Information Theory.
©2003, By Jon Hamkins