Through the variable distributed compensator and the variable distributed

摘要

PROBLEM TO BE SOLVED: To set the optimum value of a wavelength dispersion compensation value to be set to a variable DCF more accurately and in short period of time when optical transmission of high speed and large capacity is performed.;SOLUTION: A variable DCF search control part 35 observes a bit error while varying the dispersion compensation amount of the variable DCF 22 within a range that frame synchronization establishment is confirmed to search for a range which becomes error free. Next, the variable DCF search control part 35 decides the setting value of the variable DCF 22 corresponding to the center value of the range which becomes the error free to be the optimum dispersion compensation value. Then, a variable DCF control part 23 sets the optimum dispersion compensation value decided by the variable DCF search control part 35 in the variable DCF 22. Bit error monitoring time which takes time is greatly shortened by searching for the range that frame synchronization is established first, and after that, monitoring the bit error to search for the range which becomes the error free.;COPYRIGHT: (C)2009,JPO&INPIT