Telephone installation and call transmission system - has auxiliary internal connection to transfer incoming call from one receiver to another and has recall facility

摘要

The transmission system is for a central telephone exchange. The system uses a working memory and a programmed memory. A first director performs the initial connection (HS1) and a second director (HS2) connects the corresponding subscriber. The two directors are similar and are used for internal connection. If a subscriber (e.g. N'1) is already connected to another subscriber (e.g. N'2) a transfer may be made by an internal exchange connection to another subscriber (N'3). The internal connection enables a call to be interrupted and ring by a changeover on the 'in house' connection side.