Engineering aspects of TASI

For many years telephone people have been intrigued with the idea of making use of the idle time during a telephone call. Time Assignment Speech Interpolation (TASI) is a high-speed transmission and switching system based on the principle of using the free channel time to interpolate additional talkers. Although TASI requires considerable terminal equipment, it can approximately double the usefulness of long expensive channels such as the deep sea submarine cable systems. The first speech interpolation system is expected to be placed in service during 1960 on the first transatlantic telephone cable system between London and New York, which was opened for service in September 1956.