Scrambling of SONET signals is done to （）.

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• What are two characteristics of dual-ring interconnect in SONET networks? （）(Choose two.)

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• SONET Code Violations (CVs) totals in the PM tables are actually an accumulation of the number of （）.

  A . J0 errors detected in a specified interval B . errors detected in a given Errored Second (ES) C . errors detected in a given Severely Errored Second (SES) D . errors the encryption algorithm detects in a specified interval E . Bit Interleaved Parity (BIP) errors detected in a specified interval

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• Which three are advantages of SONET？（）

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• A signal of intent must be sounded in international waters by（）.

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• In the International Code of signals，a group of three letters indicates（）.

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• What approximates the signal attenuation of a plasterboard wall？（）

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• In the International Code of Signals，the code signal meaning I require immediate assistance is（）.

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• A light signal consisting of three flashes means （）.

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• All of the following are distress signals EXCEPT（）.

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• You hear the fog signal of another vessel forward of your beam.Risk of collision may exist.You MUST（）.

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• Which equipment is the primary source of generating a locating signal?（）

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• Which equipment is not a source of locating signals?（）

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• When a vessel signals her distress by means of a gun or other explosive signal，the firing should be at intervals of approximately（）.

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• What is the use of the books of Admiralty List of Lights and Fog Signals? Their use is to （）.

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• Analog signal and digital signal are two kinds of signals in the form of control.

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• Which of the following types of signals would carry the information: “Location Updati

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