AT&T Communications (1984–2010)

AT&T Communications, Inc. was a division of the AT&T Corporation that, through 23 subsidiaries, provided interexchange carrier and long-distance telephone services.

History

AT&T Long Lines Division

AT&T Long Lines was concerned with distance communications in the Bell System and used multiple mediums to provide distance communication such as by wire, cable, microwave radio relay and satellite communications that were used in conjunction to provide long-distance services for the Bell Telephone Companies and the Independent Telephone Companies. International Telephone connections to other countries used the networks which the Long Lines Division built and also provided supervision of those international connections. Originally, when AT&T was a division of The American Bell Telephone Company, (long) distance communications was the reason for the division being founded and led by Theodore N. Vail. On 30 December 1899, AT&T became the parent of the associated companies of the Bell System, when it acquired the assets of its parent company, The American Bell Telephone Company. This led to the Long Lines Division being founded to serve (long) distance communications.

Open wire and carrier systems

Before the introduction of coaxial cable and microwave relay systems, AT&T relied primarily on open-wire lines for long-distance telephone service. Early long-distance circuits required large copper conductors and loading coils to reduce attenuation over long distances. The development of vacuum-tube repeaters after 1914 allowed telephone circuits to extend across North America, culminating in the opening of transcontinental telephone service between New York and San Francisco in 1915.