Shannon capacity
In
1949,
Claude Elwood Shannon and Warren Weaver wrote
The Mathematical Theory of Communication. (ISBN 0252725484) This founded the modern discipline of
information theory. Thus it is possible to measure the amount of information in a message.
Shannon's law

where
 C = bits per second  channel capacity,
 W = frequency  bandwidth,
 S/N = signaltonoise ratio,
shows that there is a theoretical maximum amount of information that can be transmitted over a
bandwidthlimited carrier in the everpresent background
noise.