Sage data system considerations

A system for the transmission of binary digital data over telephone circuits has been developed for the SAGE (semiautomatic ground environment) System of air defense. This data transmission system had to meet stringent and varied requirements for data rate, error rate, general applicability, cost, and not least importantly, reliability in the face of enemy action. The nature of these and other requirements are discussed together with some of the history of the development program which led to the present solution. A detailed description of the data-transmission system now being installed throughout the nation is given. The conclusion contains a discussion of problems still remaining and some opinions of future trends in data-transmission systems for air defense and other applications.