System and Method for Fault Identification in Optical Communication Systems
AssigneeTyco Electronics Subsea Communications LLC
InventorHongbin Zhang
Life of this patent
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Abstract
A repeater that enables both bi-directional optical time domain reflectometry (OTDR) and loop gain monitoring techniques that may be employed, for example, in particularly long repeater spans. In one embodiment, the repeater includes high loss loopback (HLLB) paths configured to couple test signals between incoming and outgoing fiber paths. The HLLB paths are coupled from the outputs to the inputs of amplifiers within the repeater and couple both OTDR and loopback signals from an outgoing fiber path to an incoming fiber path so that may be returned to line monitoring equipment that transmitted the test signals.
Claims20
A repeater for an optical communication system, the repeater being capable of operatively coupling to an incoming fiber path and an outgoing fiber path relative to a given direction of communication, the repeater comprising:
- a first amplifier having an input and an output, and for amplifying optical signals;
- a second amplifier having an input and an output, and for amplifying optical signals;
- and
- a first high loss loop back (HLLB) path for coupling the output of the first amplifier to the input of the second amplifier, the first HLLB path being configured to
- couple an outgoing optical time domain reflectometry (OTDR) test signal from a first line monitoring equipment (LME) and reflected from the outgoing fiber path to the incoming fiber path in an incoming direction,
- couple an incoming OTDR test signal from the first LME to the incoming fiber path in an outgoing direction, and
- couple a loopback test signal from the first LME to the incoming fiber path in an incoming direction.
An optical communication system, comprising:
- a plurality of repeaters operatively coupled to provide an optical transmission path, each repeater comprising:
- a first amplifier having an input and an output, and for amplifying optical signals;
- a second amplifier having an input and an output, and for amplifying optical signals;
- a first high loss loop back (HLLB) path for coupling the output of the first amplifier to the input of the second amplifier;
- a second HLLB path for coupling the output of the second amplifier to the input of the first amplifier,
- each of the first and second HLLB paths being configured to
- couple an associated outgoing optical time domain reflectometry (OTDR) test signal reflected from an associated outgoing fiber path to an associated incoming fiber path in an associated incoming direction,
- couple an associated incoming OTDR test signal to the associated incoming fiber path in an associated outgoing direction, and
- couple an associated loopback test signal to the associated incoming fiber path in the associated incoming direction;
- a first line monitoring equipment (LME) operatively coupled to a first end of the optical transmission path for analyzing signals returned to the first LME through the first HLLB path in response to the associated outgoing OTDR test signal, the associated incoming OTDR test signal and the associated loopback test signal;
- and
- a second line monitoring equipment (LME) operatively coupled to a second end of the optical transmission path for analyzing signals returned to the second LME through the second HLLB path in response to the associated outgoing OTDR test signal, the associated incoming OTDR test signal and the associated loopback test signal.
A method of monitoring an optical communication system comprising an outgoing fiber path and an incoming fiber path, the method comprising:
- transmitting test signals comprising an outgoing optical time domain reflectometry (OTDR) test signal, an incoming OTDR test signal and a loopback test signal from line monitoring equipment (LME) onto the outgoing fiber path;
- coupling at least a portion of the test signals from the outgoing fiber path to the incoming fiber path through a repeater, the repeater comprising
- a first amplifier having an input and an output, and for amplifying optical signals,
- a second amplifier having an input and an output, and for amplifying optical signals, and
- a high loss loop back (HLLB) path for coupling the output of the first amplifier to the input of the second amplifier;
- receiving an outgoing OTDR signal in response to the outgoing OTDR test signal, an incoming OTDR signal in response to the incoming OTDR test signal and a loopback signal in response to the loopback test signal at the LME from the incoming fiber path;
- and
- analyzing the outgoing OTDR signal, the incoming OTDR signal and the loopback signal to monitor for faults in the optical communication system.
Dependencies are inferred from the claim text.