Supervisory and control signal transmitting system for use in optically amplifying repeaters system

A supervisory and control signal transmitting system for use in an optically amplifying repeater system, having a non-regenerating repeater for amplifying an optical signal received from a transmission line, for superimposing a sub signal with a carrier frequency modulated with a supervisory and control signal on said optical signal, and for supplying the resultant signal to a transmission line, said non-regenerating repeater being disposed in said transmission line, said non-regenerating repeater comprising:

• a sub signal superimposing means which includes:
• superimposing means for superimposing both said sub signal and a modulation factor stabilizing signal with a frequency different from said carrier frequency on an input signal received from said transmission line;
• optical monitoring means for monitoring an output of said superimposing means;
• and
• superimposing and stabilizing means for driving said superimposing means so as to stabilize the modulation factor of said sub signal superimposed according to an output of said optical monitoring means, and
• a stabilizing signal erasing means which includes:
• modulating means for receiving other than monitored output monitored by said optical monitoring means from said superimposing means;
• optical monitoring means for monitoring an output of said modulating means;
• and
• erasure driving means for extracting a frequency component of said modulation factor stabilizing signal according to an output of said optical monitoring means and for supplying a drive signal for erasing said modulation factor stabilizing signal to said modulating means.

An optically amplifying repeater, connected to a preceding optical repeater through an optical transmission line comprising:

• optical amplifier means for amplifying an optical signal received from said transmission line, for superimposing both said sub signal and said modulation factor stabilizing signal, and for removing the frequency component of said modulation factor stabilizing signal used in said preceding repeater;
• optical branching circuit means for branching part of the output of said optical amplifier means and for supplying other than the branched output to said transmission line;
• opto-electric converting circuit means for converting an optical signal branched by said optical branching circuit means into an electric signal;
• sub signal superimposing and stabilizing signal erasing circuit means for superimposing both said sub signal and said modulation factor stabilizing signal on the output of said opto-electric converting circuit means and for outputting a control signal for removing the frequency component of said modulation factor stabilizing signal used in the preceding optical repeater;
• and
• optical amplifier exciting light source means for receiving the output of said sub signal superimposing and stabilizing signal erasing circuit and for supplying excited light to said optical amplifier means.

An optically amplifying repeater for use in an optically amplifying repeater system for amplifying an optical signal without conversion into an electric signal and for relaying an amplified signal comprising:

• opto-electric converting means for converting to electrical signals a supervisory and control signal light from supervisory signal relaying means of said optically amplifying repeater at an earlier stage;
• defect detecting means for detecting a defect which takes place in said optically amplifying repeater;
• supervisory signal light generating means for receiving an output of said opto-electric converting means and of said defect detecting means, and for generating an optical signal of the supervisory and control signal to be supplied to a transmission line at a later stage;
• and
• supervisory signal relaying means for relaying said supervisory signal contained in an optical signal received from a preceding optically amplifying repeater at an earlier stage through a transmission line.

An optically amplifying repeater for use in an optically amplifying repeater system including reproducing repeaters, for amplifying an optical signal without conversion into an electric signal and for relaying an amplified signal comprising:

• opto-electric converting means for converting to electrical signals a supervisory and control signal light from a supervisory signal relaying means of an optically amplifying repeater at an earlier stage;
• defect detecting means for detecting a defect which takes place in said optically amplifying repeater;
• supervisory signal light generating means for receiving an output of said opto-electric converting means and of said defect detecting means, and for generating an optical signal of supervisory and control signal to be supplied for a transmission line on a later stage;
• and
• supervisory signal relaying means for relaying said supervisory signal contained in an optical signal received from a preceding optically amplifying repeater on an earlier stage through a transmission line.

A supervisory and control signal transmitting system for use in an optically amplifying repeater system for converting an optical signal received from a preceding optically amplifying repeater into an electric signal, comprising:

• supervisory signal placing means for identifying a supervisory signal generated in a preceding optically amplifying repeater and for placing said supervisory signal in a main signal of transmission data, which comprises:
• optical branching means for branching part of an optical signal received from a transmission line,
• receiving means for receiving an optical signal branched by said optical branching means,
• identifying means for identifying a supervisory signal from an output of said receiving means,
• supervisory information processing means for processing supervisory information according to an output of said identifying means,
• section overhead processing means for placing said supervisory signal in said main signal according to an output of said supervisory information processing means, and
• a unit supervisory circuit for detecting a defect which takes place in said reproducing repeater and for supplying the detected result for said supervising information processing means;
• opto-electric converting means for converting an optical signal other than the optical signal branched by said optical branching means into an electric signal and for supplying the electric signal to said section overhead processing means;
• and
• electro-optical converting means for converting an output of said section overhead processing means into an optical signal and for supplying the optical signal to a transmission line.

A supervisory and control signal transmitting system for use in an optically amplifying repeater system which includes reproducing repeaters, for converting an optical signal received from a preceding optically amplifying repeater into an electric signal, the system comprising:

• supervisory signal placing means for identifying a supervisory signal generated in a preceding optically amplifying repeater and for placing said supervisory signal in a main signal of transmission data, which comprises:
• optical branching means for branching part of an optical signal received from a transmission line,
• receiving means for receiving an optical signal branched by said optical branching means,
• identifying means for identifying a supervisory signal from an output of said receiving means,
• supervisory information processing means for processing supervisory information according to an output of said identifying means,
• section overhead processing means for placing said supervisory signal in said main signal according to an output of said supervisory information processing means, and
• a unit supervisory circuit for detecting a defect which takes place in said reproducing repeater and for supplying the detected result for said supervising information processing means;
• opto-electric converting means for converting an optical signal other than the optical signal branched by said optical branching means into an electric signal and for supplying the electric signal to said section overhead processing means;
• and
• electro-optical converting means for converting an output of said section overhead processing means into an optical signal and for supplying the optical signal to a transmission line.

An end station for an optical signal transmitting system comprising:

• a branching means for branching part of an optical signal received from said transmission line;
• a receiving means for receiving the output of said branching means;
• an identifying means for identifying a supervisory signal contained in signal light received from said receiving means;
• an opto-electric converting means for converting other than the signal branched by said branching means;
• a separating means for separating said supervisory signal from the output of said opto-electric converting means;
• and
• a supervisory and control function means for performing supervisory and control operation according to said supervisory signal received from said separating means and said identifying means.

An end station for an optical signal transmitting system including a reproducing repeater, the system comprising:

• a branching means for branching part of an optical signal received from said transmission line;
• a receiving means for receiving the output of said branching means;
• an identifying means for identifying a supervisory signal contained in signal light received from said receiving means;
• an opto-electric converting means for converting other than the signal branched by said branching means;
• a separating means for separating said supervisory signal from the output of said opto-electric converting means;
• and
• a supervisory and control function means for performing supervisory and control operation according to said supervisory signal received from said separating means and said identifying means.

A supervisory and control signal transmission method in an optically amplifying repeater of an optically amplifying repeater system wherein an optical signal transmitted through a transmission line contains transmission data as a main signal and a supervisory and control signal as a sub signal, said method comprising the steps of:

• branching a received optical signal to provide a branch signal which includes at least sub signal;
• converting the sub signal which is an optical signal to an electrical signal;
• identifying the supervisory and control signal in the sub signal which is converted from the optical signal to an electrical signal;
• supervising whether or not there are defects in the optically amplifying repeater, thereby a supervisory result;
• reproducing defect information based on the supervisory result or the supervisory and control signal;
• signalizing the defect information as an electrical signal wherein the supervisory and control signal is assigned higher priority than the supervisory result;
• generating an electrical signal for a carrier wave for use for carrying the defect information;
• modulating the generated electrical signal according to the signalized defect information;
• converting the electrical signal which is modulated according to the signalized defect information to an optical signal;
• amplifying the main signal which is an optical signal;
• composing an optical signal from the amplified main signal and the optical signal which is modulated according to the signalized defect information;
• and
• outputting the composed optical signal.

A supervisory and control signal transmission method in an optically amplifying repeater of an optically amplifying repeater system including reproducing repeaters wherein an optical signal transmitted through a transmission line contains transmission data as a main signal and a supervisory and control signal as a sub signal, said method comprising the steps of:

• branching a received optical signal to provide a branch signal which includes at least sub signal;
• converting the sub signal which is an optical signal to an electrical signal;
• identifying the supervisory and control signal in the sub signal which is converted from the optical signal to an electrical signal;
• supervising whether or not there are defects in the optically amplifying repeater, thereby a supervisory result
• reproducing defect information based on the supervisory result or the supervisory and control signal;
• signalizing the defect information as an electrical signal wherein the supervisory and control signal is assigned higher priority than the supervisory result;
• generating an electrical signal for a carrier wave for use for carrying the defect information;
• modulating the generated electrical signal according to the signalized defect information;
• converting the electrical signal which is modulated according to the signalized defect information to an optical signal;
• amplifying the main signal which is an optical signal;
• composing an optical signal from the amplified main signal and the optical signal which is modulated according to the signalized defect information;
• and
• outputting the composed optical signal.

A supervisory and control signal transmission method in a reproducing repeater of an optically amplifying repeater system wherein an optical signal transmitted through a transmission line contains transmission data as a main signal and a supervisory and control signal as a sub signal, said method comprising the steps of:

• branching a received optical signal to provide a branch signal which includes at least sub signal;
• converting the sub signal which is an optical signal to an electrical signal;
• identifying the supervisory and control signal in the sub signal which is converted from the optical signal to an electrical signal;
• supervising whether or not there are defects in the reproducing repeater, thereby a supervisory result;
• reproducing defect information based on the supervisory result or the supervisory and control signal;
• signalizing the defect information as an electrical signal wherein the supervisory and control signal is assigned higher priority than the supervisory result;
• converting the main signal which is an optical signal to an electrical signal;
• placing the signalized defect information in the main signal comprising the electrical signal;
• converting the main signal comprising the electrical signal and including the defect information to an optical signal;
• and
• outputting the optical signal including the defect information in the main signal.