( 1533 of 1533 ) |
United States Patent | 3,600,521 |
Plank , et al. | August 17, 1971 |
An automatic telephone exchange arrangement is disclosed with central control and with a central information store, individual rows in which are associated with various possible simultaneous calls, wherein each row in this information store has storage locations not only for the addresses of the calling and called subscribers but also locations for accommodating a code representing whatever program stage has been reached by the call concerned. If the telephone exchange is a private exchange, provision may be made for a subscriber to be connected to a public telephone exchange after a test has been made automatically for ascertaining whether the calling subscriber is entitled to be connected to the public exchange.
Inventors: | Plank; Karl-Ludwig (Ober-Roden, DT), Reher; Hans-Wilhelm (Salzgitter-Lebenstedt, DT), Schosnig; Johannes-Georg (Frankfurt am Main, DT) |
Appl. No.: | 04/761,444 |
Filed: | September 23, 1968 |
Sep 26, 1967 [DT] | P 15 37 904.1 | |||
Current U.S. Class: | 370/383 ; 370/384; 379/196 |
Current International Class: | H04Q 3/545 (20060101); H04Q 11/04 (20060101); H04q 003/42 (); H04j 003/00 () |
Field of Search: | 179/18,18ES,15AT |
3497630 | February 1970 | Lucas et al. |
2764634 | September 1956 | Brooks et al. |