Method for optimizing the sequence of passive filter configuration in optical mux/demux devices for wavelength division multiplex transmission systems and optical passive filter system obtained with that method
AssigneeAlcatel
InventorsStefano Enea, Alessandro Iachelini
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Abstract
The present invention provides for a method for optimizing the sequence of passive filter configuration in optical mux/demux devices for Wavelength Division Multiplex transmission systems and optical passive filter system obtained with that method, in which the optimization is obtained by taking care of the attenuation profile of the transmission optical fiber, and the variations of the spectral loss profile. The optimizing method permits to select the filter sequence maximizing the minimum span length of the network.
Claims11
A method for optimizing the sequence order of optical passive filters in WDM (Wavelength Division Multiplex) multi-channel transmission systems, said optical passive filters making up mux/demux structures at nodes of the WDM system, the method comprising:
- setting a number of parameters identifying the WDM system;
- defining the attenuation profile over different channels of the WDM system, by using said parameters;
- determining an order sequence of the different channels in a mux/demux structure from the attenuation profile;
- determining an insertion loss profile of the different channels from the order sequence;
- determining a minimum span length between nodes resulting from applying said order sequence;
- wherein the parameters identifying the WDM system comprise:
- Number of channels:
- N;
- Set of wavelengths:
- λ1 . . . λN [nm] of the N channels;
- Fiber loss profile:
- Floss(λ) [dB/km] of the optical fiber used in the WDM system;
- Insertion loss model:
- Iloss1, and Δatt [dB] of the mux/demux structure, where
- Iloss value gives the losses measured between the input (common) port and the N outputs:
- Iloss(n)=Iloss1+Δatt(n−1), Iloss1 is the insertion loss of the first port of the structure;
- Δatt is the incremental attenuation between to adjacent ports of the structure;
- n is the port position;
- Span length target:
- Slt [km] as required for the WDM system;
- Power Budget:
- Pb [dB] used between the nodes of the WDM system;
- Intermediate nodes:
- Inodes, maximum number of intermediate non-regenerative nodes.
A device comprising a mux/demux structure of passive optical filters for WDM (Wavelength Division Multiplex) multi-channel transmission system, wherein the mux/demux structure is obtained by:
- setting a number of parameters identifying the WDM system;
- defining the attenuation profile over different channels of the WDM system, by using said parameters;
- determining an order sequence of the different channels in a mux/demux structure from the attenuation profile;
- determining an insertion loss profile of the different channels from the order sequence;
- determining a minimum span length between nodes resulting from applying said order sequence;
- wherein the parameters identifying the WDM system comprise:
- Number of channels:
- N;
- Set of wavelengths:
- λ1 . . . λN [nm] of the N channels;
- Fiber loss profile:
- Floss(λ) [dB/km] of the optical fiber used in the WDM system;
- Insertion loss model:
- Iloss1, and Δatt [dB] of the mux/demux structure, where
- Iloss value gives the losses measured between the input (common) port and the N outputs:
- Iloss(N)=Iloss1+Δatt(n−1), Iloss1 is the insertion loss of the first port of the structure:
- Δatt is the incremental attenuation between to adjacent ports of the structure;
- n is the port position;
- Span length target:
- Slt [km] as required for the WDM system;
- Power Budget:
- Pb [dB] used between the nodes of the WDM system;
- Intermediate nodes:
- Inodes, maximum number of intermediate non-regenerative nodes.
A computer readable medium having a program recorded thereon, said computer readable medium comprising computer program code means adapted to perform method for optimizing the sequence order of optical passive filters in WDM (Wavelength Division Multiplex) multi-channel transmission systems, said optical passive filters making up mux/demux structures at nodes of the WDM system, the method comprising:
- setting a number of parameters identifying the WDM system;
- defining the attenuation profile over different channels of the WDM system, by using said parameters;
- determining an order sequence of the different channels in a mux/demux structure from the attenuation profile;
- determining an insertion loss profile of the different channels from the order sequence;
- determining a minimum span length between nodes resulting from applying said order sequence;
- wherein the parameters identifying the WDM system comprise:
- Number of channels:
- N;
- Set of wavelengths:
- λ1 . . . λN [nm] of the N channels;
- Fiber loss profile:
- Floss(λ) [dB/km] of the optical fiber used in the WDM system;
- Insertion loss model:
- Iloss1, and Δatt [dB] of the mux/demux structure, where
- Iloss value gives the losses measured between the input (common) port and the N outputs:
- Iloss(n)=Iloss1+Δatt(n−1), Iloss1 is the insertion loss of the first port of the structure;
- Δatt is the incremental attenuation between to adjacent ports of the structure;
- n is the port position;
- Span length target:
- Slt [km] as required for the WDM system;
- Power Budget:
- Pb [dB] used between the nodes of the WDM system;
- Intermediate nodes:
- Inodes, maximum number of intermediate non-regenerative nodes.
Dependencies are inferred from the claim text.