A method of communicating an optical signal includes generating an optical
signal at a bit rate of at least 2.5 Gb/s. The optical signal including
at least thirty optical channels. In one particular embodiment, at least
some of the thirty optical channels reside within a 1567-1620 nanometer
wavelength range. The method also includes receiving the optical signal
at a ROPA that includes a rare-earth doped optical fiber. In addition,
the method includes introducing a pump signal to a communication span of
the unrepeatered optical communication system. The pump signal operable
to amplify the optical signal by Raman amplification within the
communication span and including at least one pump signal wavelength
operable to excite the rare-earth doped fiber. The method further
includes receiving the optical signal after the optical signal has
traversed at least 200 kilometers of the communication span.