TELECOMMUNICATION SYSTEMS WITH CAPTIVE CONDITION SURVEILLANCE AND RELEASE

摘要

The subscriber stations have operationg conditions varying from an idle to a start condition and from a captive to the idle condition. The line commection circuits of the subscriber stations issue a signal indicative of a transfer of any subscriber station from the captive to the idle condition. The circuits common to the subscriber stations but separate from the central monitor the subscriber stations to the issuance of a signal indicative of a transfer of a subscriber station from the captive to the idle condition.