Patent ID: 7194210

Claim:
A method for transmitting an optical signal from a sending station to a receiving station, wherein a plurality of one or more relay stations are disposed between the sending station and the receiving station, the method comprising: receiving a transmitted signal at one of the relay stations as a received signal; separating the received signal into a plurality of bands; adjusting each band to produce a plurality of adjusted bands, including at least one of amplifying optical signals comprising each band in accordance with predetermined optical intensity parameters and adjusting a gain tilt of each band in accordance with predetermined gain tilt parameters; combining the adjusted bands to produce a transmission signal; transmitting the transmission signal to a second relay station or to the receiving station; and repeating the above steps at one or more of the relay stations; wherein the optical intensity parameters and gain tilt parameters are calculated based on a deviation of optical signal-to-noise ratios (OSNR) degradation caused by Stimulated Raman Scattering (SRS), wherein the deviation is calculated based on sectional area of one or more fibers coupling the one or more of the relay stations, an effective distance in which SRS occurs, and a Raman gain coefficient.