| 摘要 |
PROBLEM TO BE SOLVED: To improve the transmission efficiency of a data signal string of a standby system. SOLUTION: If attenuation occurs in a current system 2, a control signal generating circuit 7-2 transmits a data signal string of the system 2 on a spare line based on quality attenuation information 61-2 and quality insurance information 62-2 and generates receiving-end current signal control information 71-2, receiving terminal spare signal control information 72-2 and sending terminal control information 73-2 in order to transmit a data signal string of a standby system on a current line. An input data signal string 10-2 of the current system is transmitted on a spare line 28 through sending terminal current signal switching circuits 1-2 and 1-1 and a sending terminal spare line switch circuit 21 and outputted as a current system data signal string from a receiving terminal spare signal switch circuit 9-2. On the other hand, an input data signal string of the standby system is transmitted on the current line via a sending terminal spare signal switch circuit 2-2 of the system 2 and outputted from the standby system through receiving terminal current signal switch circuits 8-2 and 8-1 and a receiving terminal spare line switch circuit 26. |
