Telephone subscriber priority dialling system - uses branch exchange which has control of priority call routing

摘要

The telephone subscriber connection system comprises a dial telephone installation (Tn) connected to a time-multiplex trunk scheme (SS). The routing is controlled by a register and counter (Rech) and a fast-dialler which converts the code and call digits to a suitable pulse form for the transmitter (Ue). The main office branch exchange has a group selector (IGW) and line selector (LW). Internal subscribers have access to the exchange via the line selector. The exchange has access to the public network (OVSt) and is equipped with a switching selector repeater (Msp). The system allows the external subscriber direct access to an internal subscriber by means of coded priority dialling.