| 摘要 |
PURPOSE: To easily relay, at least, one auxiliary channel in an existent optical transmission channel period by inserting an auxiliary optical channel bit at a lower bit rate than a main optical channel while keeping the specified interval. CONSTITUTION: One auxiliary channel having a bit rate of, e.g. 1.7 Mbit/s is inserted to the main channel having a transmission speed or a bit rate of, e.g. 34Mbit/s. The bit of the auxiliary channel is inserted to the main optical channel as a double bit equivalent to a forbidden bit combination which is generated in the case where an electric code is code-converted into an optical code. Then, preferably, the bit of the auxiliary channel is inserted to the main channel at constant intervals, so that the relay encoder of a receiving station retrieves the contents of the auxiliary channel by identifying this interval. Thus, the bit of the auxiliary channel is inserted to the main channel without taking high expenditure. |
