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:
“Our passions do not live apart in locked chambers but dress in their small wardrobe of notions, bring their provisions to a common table and mess together, feeding out of the common store according to their appetite.”
—George Eliot [Mary Ann (or Marian)
“Just as men must give up economic control when their wives share the responsibility for the family’s financial well-being, women must give up exclusive parental control when their husbands assume more responsibility for child care.”
—Augustus Y. Napier (20th century)