A method for an optical communication network including a first and a second network element (T1, T4), the first network element comprising a first service transmitter, a first gain modulation unit and a first service receiver, and the second network element comprising a second service transmitter, a second gain modulation unit and a second service receiver, the method comprising the steps: transmitting data from the first network element by means of a first optical data signal (11,21; 37) having a first data carrier (16, 26); transmitting first service information from the first service transmitter by means of a first optical service signal having a first service carrier (13, 23); transmitting data from the second network element by means of a second optical data signal (11, 21; 37) having a second data carrier (16, 26); and transmitting second service information from the second service transmitter by means of a second optical service signal having a second service carrier (13, 23); characterized by the steps of: assigning a first spreading sequence to the first service transmitter; combining the first service information to the first spreading sequence; employing the resulting combination to intensity modulate the first service information to the first service carrier (13, 23) by means of the first gain modulation unit; outputting the first optical data signal (11, 21; 37) with additional service information; assigning a second spreading sequence to the second service transmitter; combining the second service information to the second spreading sequence; employing the resulting combination to intensity modulate the second service information to the second service carrier (13, 23) by means of the second gain modulation unit; and outputting the second optical data signal (11, 21; 37) with additional service information. transmitting data from the first network element by means of a first optical data signal (11,21; 37) having a first data carrier (16, 26); transmitting first service information from the first service transmitter by means of a first optical service signal having a first service carrier (13, 23); transmitting data from the second network element by means of a second optical data signal (11, 21; 37) having a second data carrier (16, 26); and transmitting second service information from the second service transmitter by means of a second optical service signal having a second service carrier (13, 23); characterized by the steps of: assigning a first spreading sequence to the first service transmitter; combining the first service information to the first spreading sequence; employing the resulting combination to intensity modulate the first service information to the first service carrier (13, 23) by means of the first gain modulation unit; outputting the first optical data signal (11, 21; 37) with additional service information; assigning a second spreading sequence to the second service transmitter; combining the second service information to the second spreading sequence; employing the resulting combination to intensity modulate the second service information to the second service carrier (13, 23) by means of the second gain modulation unit; and outputting the second optical data signal (11, 21; 37) with additional service information. assigning a first spreading sequence to the first service transmitter; combining the first service information to the first spreading sequence; employing the resulting combination to intensity modulate the first service information to the first service carrier (13, 23) by means of the first gain modulation unit; outputting the first optical data signal (11, 21; 37) with additional service information; assigning a second spreading sequence to the second service transmitter; combining the second service information to the second spreading sequence; employing the resulting combination to intensity modulate the second service information to the second service carrier (13, 23) by means of the second gain modulation unit; and outputting the second optical data signal (11, 21; 37) with additional service information.