Patent ID: 7616893
Filing Date: 2009-11-10
Classification: H04B,H04J

Abstract:
1. A wavelength division multiplexing optical transmission method for repeating transmission of a wavelength multiplexed optical signal along an optical transmission line interconnecting a terminal apparatus for transmission and a terminal apparatus for reception and having a plurality of divisional intervals into which the optical transmission line is divided by a plurality of apparatuses, comprising steps executed by each of said apparatuses disposed at end points of the divisional intervals, the steps including: a first dispersion compensation step of compensating for a dispersion included in the wavelength multiplexed optical signal having propagated in the divisional repeating interval on the terminal apparatus side for transmission so that a remaining dispersion amount is within a tolerance set in advance; an optical add/drop multiplexing step of performing an optical add/drop multiplexing for each of wavelength components of the wavelength multiplexed optical signal for which the dispersion compensation has been performed at the first dispersion compensation step; a second dispersion compensation step of performing a dispersion compensation with an additional compensation amount to the compensation amount of the first dispersion compensation step for the wavelength multiplexed optical signal for which the optical add/drop multiplexing has been performed at the optical add/drop multiplexing step, said additional compensation amount is from 5 to 20 percent of a total dispersion amount occurred in the divisional repeating intervals on the terminal apparatus side for transmission; a ratio of the additional compensation amount at the second dispersion compensation step to the sum of the dispersion compensation amounts at the first and second dispersion compensation steps being set so as to gradually increase with the transmission distance between said terminal apparatus for transmission and a corresponding one of said apparatuses; and a third dispersion compensation step of performing a dispersion compensation with additional compensation amounts to dispersions at optical reception sections each of which performs a reception process for one of demultiplexed optical signals whose dispersion values of the wavelengths have been optimally compensated for by fine-tunable variable dispersion compensators respectively.