schaltungsanordnung for telecommunications, in particular telephone with automatic equipment for link tracking

摘要

1,122,289. Automatic exchange systems. SIEMENS A.G. 27 July, 1966 [28 July, 1965], No. 33764/66. Heading H4K. In an exchange operating under programme control, the calling number as determined by an identifier JD is stored in a register SP associated with a link RSA throughout the connection. Should it be necessary to trace an anonymous caller, a device FE is actuated by an action on the part of the called party and an A.C. signal outside the speech band is applied from the generator G, and the links RSA are scanned until the signal is detected by a receiver E. Thus the connection path is determined. It is stated that the connection may be traced when the calling party fails to clear, or if he reports inability to call a particular number.