In
telephone systems nomenclature, a
long line is a transmission line in a long-distance
communications network such as
carrier systems,
microwave radio relay links, geosynchronous
satellite links, underground cables,
aerial cables and open wire, and
Submarine communications cables. In the
United States, some of this technology was spun off into the corporate entity known as
AT&T Long Distance with the
breakup of AT&T in 1984. Prior to then, the
AT&T Long Lines division of the
Bell System, which was what AT&T called itself when it was responsible for providing both long distance and local telephone service before the
1984 breakup, provided maintenance and installation of long line facilities for the Bell System's long distance service.