GB1132144A - Telegraphic concentrator - Google Patents

Abstract

1,132,144. Telegraphy. CIT-COMPAGNIE INDUSTRIELLE DES TELECOMMUNICATIONS S.A. 6 Sept., 1966 [15 Sept., 1965], No. 39734/66. Heading H4P. A telegraph system comprises a number of subscribers connected at 1 to a concentrator ED and a similar number connected to remote exchange at 2 via a similar unit EC. ED is connected via a lesser number of lines J to EC, which is at the exchange. When a subscriber at 1 wishes to call another subscriber at 1, I 1 finds a free line J and connects it to E 1 , and stores the caller's number. E 1 calls unit EC, in response to which the exchange requests the caller's number. On receipt of this number the unit EJ 2 connected to the selected line J is connected to a subscriber unit EA 2 corresponding to that (EA 1 ) associated with the caller. EA 1 and EA 2 are now connected via cross-bar switches C 1 , C 2 . The caller then sends the called number, and the exchange at 2 selects the corresponding subscriber unit EA 2 . I 2 now finds a free line as did I 1 earlier, and in similar manner selection of the subscriber unit EA 1 of the called subscriber is accomplished. When the exchange requests the caller's number its request is preceded by a signal indicating whether the exchange or the stations at 1 initiated the connection. This signal gives the exchange priority over the remote stations.