Method and Network Control Device for Computing a Set of Optimal Amplification Parameters for a Span of a Multi-Span Optical Fiber Network

A method for setting amplification parameters for a span of a multi-span optical fiber network, wherein each span has an associated optical transmission fiber connected to associated amplifiers, wherein the associated amplifiers comprise a forward Raman amplifier and at least one discrete amplifier, wherein gain and output power of the at least one discrete amplifier are respectively controlled independently, wherein the at least one discrete amplifier is connected to launch optical signals into a remainder of a corresponding optical transmission line, the method comprising:

• computing a set of optimal amplification parameters for a corresponding span by providing an analytical form of a signal power evolution along a corresponding span;
• computing a linear noise from amplifier noise figures and a non-linear noise generated in the corresponding span based on information about the span and the analytical form of the signal power evolution and using the computed linear noise and non-linear noise to compute an impact on a span performance;
• and computing the set of optimal amplification parameters for the corresponding span based on the impact on the span performance;
• and
• setting the amplification parameters of the corresponding span based on the computed set of optimal amplification parameters.

A network control device for computing a set of optimal amplification parameters for a span of a multi-span optical fiber network, wherein each span has an associated optical transmission fiber connected to associated amplifiers, wherein the associated amplifiers comprise a forward Raman amplifier and at least one discrete amplifier, wherein gain and output power of the at least one discrete amplifier are respectively controlled independently, wherein a last of the at least one discrete amplifier is connected to launch optical signals into a remainder of a corresponding optical transmission line, the network control device comprising:

• a providing unit configured to provide an analytical form of the signal power evolution along a corresponding span;
• a first computing unit configured to compute a linear noise from amplifier noise figures and a non-linear noise generated in the corresponding span based on information about the span and the analytical form of the signal power evolution and to use the computed linear noise and non-linear noise to compute an impact on a span performance;
• and
• a second computing unit configured to compute the set of optimal amplification parameters for the corresponding span based on the impact on the span performance.