fibers 22 between pump modules 20 the number of pump modules 20 and the losses in each span as well as the launch power of the optical signal fig6 shows the signal power versus transmission distance for multiple launch powers in a unity gain system with adjusted steady state powers consistent with the present invention as shown in fig6 for launch powers greater than the nominal launch power the steady state power levels reached toward the end of the transmission are lower than the nominal output power conversely for launch powers lower than the nominal launch power the steady state power levels reached toward the end of the transmission are higher than the nominal output power the lowered output power for the higher launch powers and the raised output power for the lower launch powers can be achieved by controlling the pump powers of the pump modules 20 for example to get the output power of the optical signal to be higher than the nominal output power where the launch power is lower than the nominal launch power the pump powers of the pump modules 20 may be increased the increased pump power can be adjustable depending on the position of each pump module 20 more preferably each pump module is configured to provide the same amount of pump power with the amount provided being sufficient to raise the output power of the optical signal to be greater than the nominal output power for the launch powers that are greater than the nominal launch power the pump powers of the pump modules 20 may be decreased either by adjusting.