To optimize the resources of an optical transmission network using
wavelength division multiplexing, assigning carrier frequencies to
signals to be transmitted consists in associating N sets of optical
frequencies of the comb with N respective ranges of consecutive error
rate values, each of the sets comprising frequencies generating a mean
error rate in the associated range, defining a measured signal
transmission constraint level that is a function of the transmission
constraint parameter(s) and may take N distinct values referred to as
constraint values, associating the N constraint values in increasing
order respectively with the N sets of frequencies in decreasing order of
the error rate values of the associated N ranges, assigning any signal to
be transmitted a constraint value obtained by applying the measurement,
and assigning the signal to be transmitted a carrier frequency belonging
to one of the sets of frequencies that is associated with a constraint
value at least equal to the constraint value assigned to the signal to be
transmitted.