In telecommunication, a common control is an automatic telephone exchange arrangement in which the control equipment necessary for the establishment of connections is shared by being associated with a given call only during the period required to accomplish the control function for the given call. The first examples deployed on a major scale were the Director telephone system in London and the panel switch in the Bell System. Direct control telephone exchanges became rare in the 1960s, leaving only common control ones.
Note: During the 1980s, common control exchanges became stored program control exchanges, using common-channel signaling in which the channels that are used for signaling, whether frequency bands or time slots, are not used for message traffic.
Famous quotes containing the words common and/or control:
“By common consent of all the nations and all the ages the most valuable thing in this world is the homage of men, whether deserved or undeserved.”
—Mark Twain [Samuel Langhorne Clemens] (1835–1910)
“He took control of me for forty-five minutes. This time I’ll have control over him for the rest of his life. If he gets out fifteen years from now, I’ll know. I’ll check on him every three months through police computers. If he makes one mistake he’s going down again. I’ll make sure. I’m his worst enemy now.”
—Elizabeth Wilson, U.S. crime victim. As quoted in People magazine, p. 88 (May 31, 1993)