| 摘要 |
PURPOSE:To ensure an efficient operation of an automatic switchboard with a low charge, by having an automatic selection for the connection route of a trunk line by the service priority and forming a calling loop. CONSTITUTION:A calling subscriber has the dialing of a trunk line, and this dial information is transmitted to a central control part 4 via a subscriber circuit 2 and a subscriber control part 3. Then the dial information is analyzed at the part 4 to decide the territory of the dialing. At the same time, the part 4 knows the priority of the calling subscriber from the data on each telephone set at a memory 11 since the calling telephone is previously informed to the part 4. The state of a trunk 7 is controlled at the part 4 and via a trunk control part 8, and the idle state of the connecting route of the trunk line is searched at the part 4 on the basis of the idle information of each trunk 7. Therefore an automatic switchboard can be efficiently operated with a low charge in such case that the charge is different by the time and the data. |
