| 摘要 |
PURPOSE:To increase the degree of freedom for system constitution, by providing the master unit which makes exchange of the digital signal of line concentration system and nonline concentration system between the digital transmission line and the exchanger. CONSTITUTION:Subscriber telephone sets 1, 2 are connected to the master device 7 via remote terminal stations 3, 4 and PCM relay transmission lines 5, 6. The digital exchanger 8 is connected to the device 7. The exchanger 8 divides the constitution of switch into the line concentration stage and the distribution stage, and the usage efficiency of the distribution stage switch is increased, by the reduced subscribers. The interface with the distribution stage is provided with the master device to connect the digital subscribing line carrier system of nonline concentration system, and the device 7 makes line concentration or inverse concentration based on the line concentration control information. The signal of concentration is handled at the exchanger 8 and the signal of nonconcentration is handled at the transmission lines 5 and 6. |
