Patent ID: 7567760

Claim:
A method of monitoring the performance of an electronic dispersion compensator which receives an optical signal and generates an equalised signal, in which the electronic dispersion compensatory includes an equalisation coefficient generator, the method comprising the steps of: receiving a signal from the equalisation coefficient generators; and generating an alarm in dependence upon said signal; wherein the equalisation coefficient generator performs the steps of converting the equalised signal to a digital signal; and comparing said digital signal to said equalised signal to provide an error signal; wherein the signal received from the egualisation coefficient generator is said digital signal; wherein the generating step comprises the sub-steps of sampling the output signal using a plurality of voltage thresholds wherein said sampling of the output signal uses a clock utilising a plurality of phase delays; determining the bit error rate for a plurality of combinations of voltage threshold and phase delay; determining an eye opening voltage at which the bit error rate exceeds a predetermined bit error threshold; determining an eye opening phase delay at which the bit error rate exceeds a predetermined bit error threshold; and generating the alarm when either the eye opening voltage less than a voltage predetermined threshold or the eye opening phase delay is less than a phase delay predetermined threshold.