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 40
first selector banks are multipled together so as to mingle thetraffic and prevent any one group of ten trunks from being over loaded.All A sections may be multipled together, all B sections together, etc.;or the A and B sections may be tied together, the C and D, etc. Some-times the multipling is… … =g^ Fig. 21.—Inter-office trunking (100,000-line system). 24 AUTOMATIC TELEPHONY all the local banks in the same way. It is entirely a matter of trafficrequirements. Economies can be secured by bringing into one group all the trunksfrom one office to another. To secure this end outgoing…
Telephone
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