| 摘要 |
PURPOSE:To ensure the sufficient transmission capacity of a sub signal in a terminal station repeater by using the transmission of the sub signal inserted digitally and the transmission of a main digital optical signal modulated by the sub signal analogically so as to reduce the power consumption in the intermediate repeater. CONSTITUTION:In sending the sub signal between terminal station repeaters 1, a sub signal digital insertion demultiplexing circuit 10 applies digital bit insertion of the sub signal to the main digital signal and in sending the sub signal between the terminal station repeater 1 and the intermediate repeater 2 and between the intermediate repeaters 2, a sub signal analog modulating/ dividing circuit 20 applies amplitude modulation to the main digital optical signal by the sub signal. Thus, the power consumption is less in the intermediate repeaters 2 and the sufficient transmission capacity of the sub signal is ensured in the terminal station repeater 1. |
