Patent ID: 6915076
Filing Date: 2005-07-05
Classification: H04B

Abstract:
1. In an optical network with an optical detection circuit residing on a first optical node, a second upstream optical node having an optical amplifier generating optical noise adapted to amplify an optical data stream, and an optical path link coupling the optical detection circuit in the first node and an output of the optical amplifier of the second node, the optical path link having an optical attenuation with a range of attenuation between a minimum attenuation and a maximum attenuation, a method of selecting a signal detection threshold for an optical input received by the optical detection circuit appropriate for the optical attenuation of the optical path link, the method comprising: receiving a first signal indicative of an average power level of the optical input; receiving a second signal indicative of a peak power level of the optical input; and selecting the signal detection threshold to distinguish an optical signal condition from a loss of signal condition appropriate for the optical attenuation of the optical path link, the signal detection threshold selected to have an associated threshold power level that is greater than a peak power level for an optical input composed of optical noise having the average power level and less than a peak power level for an optical input composed of optical data pulses having the average power level; the signal detection circuit operable for the range of attenuation of the optical path link being sufficiently large that the threshold power level is adjusted at least once over the range of attenuation.