| 摘要 |
PURPOSE:To improve the reliability of a system including the transmission line between multiplex carrier devices and to utilize a stand-by transmission line, by connecting in-use and stand-by transmission line as the transmission line between multiplex carrier devices through the switching of a switching circuit. CONSTITUTION:The transmission output of multiplex carrier device 1 having transmission band f1 is passed through branching circuit 2 and one output is led to the transmission side of in-use transmission line 9 to be sent to the opposite side. The other output is inputted to integrating circuit 6 and mixed with the transmission output of multiplex carrier device 5, and the resulting mixture signal is led to the transmission side of stand-by transmission line 10 to be sent to the opposite-side terminal. At the opposite reception side, on the other hand, the reception output of transmission line 9 is passed through switching circuit 3 which selects either one of in-use and stand-by transmission lines and supplied to the reception input side of multiplex carrier device 4 with transmission band f2. Thus, the in-use and stand-by transmissions are used by being switched to improve the reliability of the system including the transmission lines between the multiplex carrier devices and also to utilize the stand-by transmission line. |
