Patent ID: 7391974

Claim:
A wavelength division multiplexing transmission system comprising; a first relay node transmitting an optical signal from a first transmission path to a second transmission path, amplifying the optical signal with a fast optical amplifier and adjusting a light output intensity variance by a wavelength of the optical signal with a first gain tilt controller; a second relay node transmitting the optical signal received from the first relay node via the second transmission path to a third transmission path, amplifying the optical signal with a second optical amplifier and adjusting a light output intensity variance by a wavelength of the optical signal with a second gain tilt controller; and a control node setting values of light output intensity for each of the first optical amplifier and the second optical amplifier and setting values of gain tilt for each of the first gain tilt controller and the second gain tilt controller, wherein the control node calculates the values of light output intensity and gain tilt for each of the optical amplifiers and the gain tilt controllers so that a deviation of OSNR degradation caused by SRS can be rectified, and wherein the control node calculates the deviation based on sectional area as the first transmission path, the second transmission path, the third transmission path, an effective distance in which SRS occurs, and a Raman gain coefficient.