| 摘要 |
<P>PROBLEM TO BE SOLVED: To reduce the number of bit errors of an optical signal by shortening a switching time of a PLL reference clock in interruption of an optical signal to be inputted to a transmission apparatus and input recovery of the optical signal in an optical communication technology of a transmission rate of 40 Gb/s. <P>SOLUTION: An optical transmission apparatus 100a according to the present invention which connects a terminal apparatus side in which a transmission line is formed by SONET/SDH having a transmission rate of 39.813 Gb/s of an OC768 or STM-256, and a WDM side in which a transmission line is formed by OTU 3 having a transmission rate of 43.018 Gb/s, includes a selector 109 that, when an input signal is interrupted or switched, controls a PLL unit 106 so as to switch and obtain a clock signal of a predetermined frequency oscillated by an OSC 108, corresponding to a frequency of a clock signal of the input signal before being divided to input into the PLL unit 106, as a clock signal to generate a PLL reference frequency. <P>COPYRIGHT: (C)2009,JPO&INPIT |
