This involves first converting the speech to binary digital form, which results in a data stream typically between 16, 000 and 64, 000 bits per second. Devices that do this are called analog-to-digital converters. The digital data are then scrambled, as discussed below. ... Private branch telephone exchanges have evolved since the early 1900s from manual private branch exchanges in which all switchinganbsp;...
|Title||:||McGraw-Hill Encyclopedia of Science and Technology Volume 14|