Automatic telephony; a comprehensive treatise on automatic and semi-automatic systems (1921)
Smith, Arthur Bessey, b. 1875, Campbell, Wilson Lee · New York : McGraw-Hill · leaf 45
ict 2, the place depending on economy of trunks. It is usual to locate these second selectors in the most convenient ofthe offices of the district. But if the conditions warrant, they may beput in a building by themselves, with no local subscriber lines at all. Inthis case it is a switching office,… … Fig. 27.—Large exchange, second selectors in their own districts. Tandem trunking is the term applied to the idea of selectors locatedat an intermediate office to switch calls between other offices. The termholds in both the cases described above. The outgoing trunks from an office need not be…
Telephone
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