File:Bell telephone magazine (1922) (14755784102).jpg

Identifier: belltelephonemag4344amerrich (find matches)
Title: Bell telephone magazine
Year: 1922 (1920s)
Authors: American Telephone and Telegraph Company American Telephone and Telegraph Company. Information Dept
Subjects: Telephone
Publisher: (New York, American Telephone and Telegraph Co., etc.)
Contributing Library: Prelinger Library
Digitizing Sponsor: Internet Archive

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BELL LABORATORIES BIGGEST JOB translation. The customers telephoneline no longer needs to be connected tospecific physical terminals in the switch-ing network. The common control equip-ment can translate the telephone num-bers into an arbitrary terminal number.It can also translate the dialed digits toprovide alternate connecting paths withinthe central office or between central of-fices-—something step-by-step switchingcannot do. These two concepts—common controland translation—have made it possibleto make major advances in nationwideand worldwide direct distance dialing. Crossbar switching is very successful.Its reliability is almost legendary—about11 minutes down time per 40 years ofoperation for a central office. And be-cause the crossbar system is made upof small, nearly identical sections, it iseconomical to produce because of thelarge production volumes of its individ-ual parts. The market for crossbar sys-tems is broad, too, since it can serveeconomically all but the v

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