OCR Text |
Show Telephone Company Tests Mechanisms The world's most efficient telephone tele-phone mechanism, which takes advantage of even the slightest pause in a telephone conversation conversa-tion is now undergoing preliminary prelimi-nary tests on a transatlantic cable system, H. K. Richmond, district manager of the Mountain States Telephone Company said. The long lines department of American Telephone and Telegraph Tele-graph Company is conducting the tests over a telephone cable system that links the U. S. with Great Britain. The new device, called TASI for Time Assignment Assign-ment Speech Interpolation, is completley transistorized and will approximately double the original capacity of the cable system TASI is due to go into service this summer. The cable system, similar to those that now connect the main land of the U. S. with continental Europe, Hawaii and Alaska, is presently equipped to carry 48 simultaneous conversations. Mr. Richmond said this is the way TASI works: An overseas call, like most long distance conversations,- travels over a pair of channels, one for each direction of speech. As one party speaks the second party listens. Thus, one channel is being used while the other is idle. When a speaker pauses to catch his breath or collect col-lect his thoughts, both channels become idle. Whenever the number of calls exceed the number of voice paths available, TASI takes advantage of the idle speech time by flicking flick-ing voices from channel to channel. chan-nel. In other words, a talker's voice may travel over several different channels during the course of a conversation. Just before be-fore these "talk spurts" reach the listener, they are sorted out and re-united by TASI to assure smooth transmission and, at the same time, maintain complete privacy. To find idle moments in channels, TASI examines each one 8,000 times a second. Studies have shown that the two channels used for an average aver-age conversation are idle more than half of the time. The electronic system designed by Bell Laboratories, cost about $3,500,000 to install. The terminal termi-nal equipment consists of 17 compact cabinets. One set of cabinets cab-inets is at White Plains, N. Y., and another in London. Each contains 10,000 transistors and 106,000 other components. Due to the cost of this equipment, it will not be used on local exchange ex-change facilities. |