Cisco Cisco 1 GHz GainStar Node 安装指南
Troubleshooting Carrier-to-Noise Problems
OL-31947-02
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Troubleshooting Carrier-to-Noise Problems
Complete the following steps to troubleshoot carrier-to-noise problems.
Carrier-to-noise problems troubleshooting table
Possible Cause
Solution
Low optical input to the
GainStar Mini Node. The
typical optical input level
should be -4 to +2 dBm. Refer
to the system design print for
the proper level.
GainStar Mini Node. The
typical optical input level
should be -4 to +2 dBm. Refer
to the system design print for
the proper level.
Clean the connectors if they are contaminated. Refer
to Cleaning Optical Connectors.
to Cleaning Optical Connectors.
Inspect fiber routing that might be wrapped too
tightly.
Check the transmitter for the proper optical output.
Check the link loss.
Replace any scratched connectors.
tightly.
Check the transmitter for the proper optical output.
Check the link loss.
Replace any scratched connectors.
Low RF input at the
transmitter.
transmitter.
Check the RF input to the transmitter.
Check all the amplifiers preceding the transmitter for
the proper inputs and outputs.
Check all the amplifiers preceding the transmitter for
the proper inputs and outputs.
Failure in the optical receiver. Replace the GainStar Mini Node module.
Defective or improperly
spliced optical coupler
between the headend
transmitter and the node.
spliced optical coupler
between the headend
transmitter and the node.
Replace or re-splice the coupler.
Make sure all the unused fiber pigtails are
terminated.
Make sure all the unused fiber pigtails are
terminated.
Unterminated leg of the optical
coupler.
coupler.
Make sure all the unused fiber pigtails are
terminated.
terminated.