1.1.4 From Analog To Digital Communications

The twentieth century saw communications expanding beyond text and speech. John Logie Baird demonstrated practical television systems capable of transmitting moving images, creating an entirely new communications medium. Radar developments led by figures such as Robert Watson-Watt expanded the use of radio for detection and navigation. Improvements in electronic devices, signal processing, and network engineering continually increased communications capacity and reliability.

At the same time, communications became increasingly digital. Baudot’s and Murray’s coding systems anticipated later developments in information representation. Ralph Hartley introduced quantitative measures of information, while Claude Shannon established information theory, defining the fundamental limits of communication systems and providing the mathematical foundations of the digital age. Shannon’s work influenced everything from computer networks and mobile communications to data compression and error-correction coding.