Juniper Networks, Inc.

Xuan He

Qiang Wang

Yang Yue

In some embodiments, an apparatus includes a memory and a processor operatively coupled to the memory. The processor is configured to be operatively coupled to a first optical transponder and a second optical transponder. The processor is configured to receive, from the second optical transponder, a signal representing a skew value of an optical signal and a signal representing a bit-error-rate (BER) value of the optical signal. The skew value is associated with a skew between an in-phase component of the optical signal and a quadrature component of the optical signal. The processor is configured to determine, based on at least one of the skew value or the BER value, if a performance degradation of the first optical transponder satisfies a threshold. The processor is configured to send a control signal to the first optical transponder to adjust a pulse shaping or a data baud rate of the first optical transponder.

Methods and apparatus for improving the skew tolerance of a coherent optical transponder in an optical communication system

In some embodiments, an apparatus includes an optical transceiver having a photo diode and a processor configured to be operatively coupled to the photo diode. The photo diode is configured to measure a set of receiver optical power (ROP) values at a set of baud rate values. The processor is configured to measure a set of bit error rate (BER) values of a digital modulated signal at the set of baud rate values. The processor is configured to determine an estimated optical signal noise ratio (OSNR) value at a baud rate value from the set of baud rate values based on the set of ROP values and the set of BER values. The processor is configured to send a signal indicating the estimated OSNR value at the baud rate value such that a planned route is selected to send data signals based on the estimated OSNR value.

Methods and apparatus for predicting and monitoring performance of a coherent optical transceiver at various baud rates

In some embodiments, a non-transitory processor-readable medium storing code representing instructions to be executed by a processor comprises code to cause the processor to determine, during a calibration of a coherent optical transmitter, a set of parameters associated with each tributary channel by sending a first signal to a digital signal processor (DSP) to adjust a scale factor of that tributary channel. The scale factor is associated with a tap characteristic of a finite impulse response (FIR) filter of the DSP. The code further causes the processor to determine a power imbalance between two tributary channels based on the set of parameters associated with each tributary channel. The code further causes the processor to send a second signal to the coherent optical transmitter to adjust a set of operational settings of the coherent optical transmitter based on the power imbalance and the set of parameters associated with each tributary channel.

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San Jose, CA, United States of America

Xuan He