System and method for a channel guard in a reconfigurable optical add-drop multiplexer
AssigneeCiena Corporation
InventorsDouglas James Beckett, Brandon Collings, Lawrence J. Nociolo, Eddie Fung
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Abstract
The present invention provides a colorless multiplexing system and method for detecting new optical channels at power levels below that which would cause data errors in existing traffic, and on top of background light, thus, overcoming a known risk inherent in colorless multiplexing—that a channel of the same wavelength as an existing channel is incorrectly added to the original working, traffic-carrying, channel's path.
Claims18
A method for validating new channel wavelengths in a reconfigurable optical add-drop multiplexer at power levels below that which would cause data errors in existing traffic, and on top of background light, comprising:
- connecting a data card to an add port and bringing the data card to a minimum detectable wavelength and power;
- modulating, in log-sinusoidal, an add-port variable optical attenuator (VOA) with a modulation frequency uniquely corresponding to the add port;
- recording a time series of a plurality of transmission power data messages;
- computing a fast-Fourier transform (FFT) of the recorded time series data, from which a power spectrum (power versus frequency) is calculated;
- identifying a one or more modulation frequency component that corresponds to predetermined detection criteria;
- and
- comparing the identified one or more identified frequency with the one or more modulated frequency.
A method for validating a new add channel wavelength in colorless multiplexing, comprising:
- connecting a data card to an add port and bringing the data card to a minimum detectable wavelength and power;
- modulating an add-port variable optical attenuator (VOA) with a modulation frequency uniquely corresponding to the add port;
- recording a time series of a plurality of transmission power data messages with a digital signal processor;
- computing a fast-Fourier transform (FFT) of the recorded time series data with the digital signal processor, wherein a power spectrum (power versus frequency) is calculated from the FFT;
- and
- determining if a channel is being added of the same wavelength as an existing channel by identifying one or more modulation frequency component that corresponds to predetermined detection criteria and comparing the modulation frequency with the identified one or more modulation frequency component.
A system for validating a new add channel wavelength in colorless multiplexing, at power levels below that which would cause data errors in existing traffic, and on top of background light, comprising:
- an add port in a reconfigurable optical add-drop multiplexer;
- an add-port variable optical attenuator (VOA);
- a data card, connected to the add port, wherein the data card is brought to an operational wavelength and power;
- a digital signal processor that modulates the add-port VOA with a modulation frequency uniquely corresponding to the add port;
- wherein the digital signal processor records a time series of a plurality of transmission power data messages and computes a fast-Fourier transform (FFT) of the recorded time series data, from which a power spectrum (power versus frequency) is calculated;
- wherein a one or more modulation frequency component that corresponds to predetermined detection criteria is identified;
- and
- wherein the one or more identified frequency is compared with the one or more modulated frequency.
Dependencies are inferred from the claim text.