| 摘要 |
PURPOSE:To improve higher-speed service for mutual connection between exchanges by transmitting information such as a telephone number required for exchange connection in a high speed serial line and using the line for hook on/off supervision of a caller and a called party and for two-way talking. CONSTITUTION:Subscriber telephone sets 4, 5, 6 are connected respectively to cable broadcast exchanges 1, 2, 3. Exchanges #1, #2 are connected by inter- station connectors 7, 9 of exclusive use between the two stations and a couple of lines 11. Similarly exchanges #2, #3 are connected by inter-station connectors 12, 14 and lines 16. Exchanges #1, #3 are connected similarly inter-station connectors 17, 19 and lines 21. A connection request telephone number from a sender station is transmitted through a high-speed serial interface circuit 8. When the reception station is possible for connection, a changeover relay is set, an affirmative response is returned to form a channel. |
