Automatic switching system

This article does not cite any references or sources. Please help improve this article by adding citations to reliable sources. Unverifiable material may be challenged and removed. (February 2007)

In data communications, an automatic switching system is a switching system in which all the operations required to execute the three phases of information-transfer transactions are automatically executed in response to signals from a user end-instrument.

In an automatic switching system, the information-transfer transaction is performed without human intervention, except for initiation of the access phase and the disengagement phase by a user.

In telephony, it refers to a telephone exchange in which all the operations required to set up, supervise, and release connections required for telephone calls are automatically performed in response to signals from a calling device. This distinction lost importance as manual switching declined during the 20th century.