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:
“This was the noblest Roman of them all.
All the conspirators save only he
Did that they did in envy of great Caesar.
He only, in a general honest thought
And common good to all, made one of them.”
—William Shakespeare (1564–1616)
“Our culture still holds mothers almost exclusively responsible when things go wrong with the kids. Sensing this ultimate accountability, women are understandably reluctant to give up control or veto power. If the finger of blame was eventually going to point in your direction, wouldn’t you be?”
—Ron Taffel (20th century)