Patent ID: 7809262
Filing Date: 2010-10-05
Classification: H04Q

Abstract:
1. A method for determining a location of a fiber cut in a passive optical network (PON) including a plurality of optical network terminations (ONTs), the method comprising: generating a plurality of base signatures prior to the fiber cut, each of the base signatures corresponding to a known configuration of the plurality of ONTs, wherein generating a plurality of base signatures comprises configuring each of the plurality of ONTs to correspond to a working ONT or a non-working ONT, transmitting at least one optical test pulse to each of the plurality of ONTs, in response to transmitting the at least one optical test pulse, receiving back-scattered light and reflected light from the plurality of ONTs, measuring an intensity and an arrival time of the back-scattered light and reflected light, and plotting the intensity and the arrival time of the back-scattered light and reflected light as a function of a length of fibers between an optical splitter and the plurality of ONTs, wherein configuring each of the plurality of ONTs to correspond to a working ONT comprises enabling a physical layer loop back unit at each ONT to be configured as a working ONT, and wherein configuring each of the plurality of ONTs to correspond to a non-working ONT comprises disabling the physical layer loop back unit at each ONT to be configured as a non-working ONT, the physical layer loop back unit configured to reflect back the at least one optical test pulse, when enabled; in response to the fiber cut, generating a current signature corresponding to a current configuration of the plurality of ONTs; determining whether the current signature matches one of the base signatures; and in response to finding a matching base signature, determining the location of the fiber cut based on the known configuration of the plurality of ONTs corresponding to the matching base signature.