Optical network system with quality control function
First Claim
1. An optical network system with quality control function in the optical network system wherein a signal to be transmitted is converted to an optical signal of a prescribed wavelength and transmitted over an optical transmission path by a transmit-end wavelength convener;
- and said optical signal from said optical transmission path is received and wavelength-converted by a receive-end wavelength converter, for regenerating the signal to be transmitted, the optical network system comprising;
said transmit-end wavelength converter for a transmit end with a first transponder further comprising;
an optical signal input unit for inputting an optical signal to be transmitted;
a test signal generator circuit ultimately connected to said optical signal input unit for generating a test signal for testing optical transmission quality, said test signal generator circuit further comprising;
a clock generator for generating a clock signal indicative of a bit rate to be added to the test signal;
an ‘
all 1s and all 0s’
generator circuit for generating ‘
all 1s and all 0s’
signals; and
a scrambler circuit connected to said ‘
all 1s and all 0s’
generator circuit for scrambling the ‘
all 1s and all 0s’
signals to generate a scrambled test signal;
an insertion circuit connected to said optical signal input unit and said test signal generator circuit for outputting an output signal by selectively inserting the test signal from said test signal generator circuit into the transmission path formed between the transmit end and a receive end; and
a converter connected to said insertion circuit for converting the output signal of said insertion circuit to a predetermined optical wavelength; and
said receive-end wavelength converter at the receive end with a second transponder further comprising;
an extraction circuit for selectively extracting the test signal in the optical signal from said transmission path;
a test comparison circuit connected to said extraction circuit for determining the optical transmission quality based on the test signal extracted by said extraction circuit, said test comparison circuit further comprising;
a clock extraction circuit for extracting the clock signal from the test signal that is received at the receive end in order to synchronize with the bit rate of the selected test signal;
a descrambler circuit connected to said clock extraction circuit for using the clock component for descrambling the scrambled test signal to generate descrambled signals;
a selector circuit connected to said descrambler unit for selecting one of the descrambled signals from said descrambler circuit; and
a comparison test circuit connected to said selector circuit for performing a test signal comparison and a bit error count/computation of the selected descrambled signal.
1 Assignment
0 Petitions
Accused Products
Abstract
To ensure transmission in a flexible optical network system, a digital test signal generation/comparison circuit is incorporated in an electrical signal processing portion of a transponder. The optical network system provides transparent wavelength-division multiplex service regardless of the signal type in client optical signals. Prior to connecting a client optical line to the optical system, a selective insertion unit and a selective extraction unit enable quality assessment of the client optical line.
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Citations
24 Claims
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1. An optical network system with quality control function in the optical network system wherein a signal to be transmitted is converted to an optical signal of a prescribed wavelength and transmitted over an optical transmission path by a transmit-end wavelength convener;
- and said optical signal from said optical transmission path is received and wavelength-converted by a receive-end wavelength converter, for regenerating the signal to be transmitted, the optical network system comprising;
said transmit-end wavelength converter for a transmit end with a first transponder further comprising;
an optical signal input unit for inputting an optical signal to be transmitted;
a test signal generator circuit ultimately connected to said optical signal input unit for generating a test signal for testing optical transmission quality, said test signal generator circuit further comprising;
a clock generator for generating a clock signal indicative of a bit rate to be added to the test signal;
an ‘
all 1s and all 0s’
generator circuit for generating ‘
all 1s and all 0s’
signals; and
a scrambler circuit connected to said ‘
all 1s and all 0s’
generator circuit for scrambling the ‘
all 1s and all 0s’
signals to generate a scrambled test signal;
an insertion circuit connected to said optical signal input unit and said test signal generator circuit for outputting an output signal by selectively inserting the test signal from said test signal generator circuit into the transmission path formed between the transmit end and a receive end; and
a converter connected to said insertion circuit for converting the output signal of said insertion circuit to a predetermined optical wavelength; and
said receive-end wavelength converter at the receive end with a second transponder further comprising;
an extraction circuit for selectively extracting the test signal in the optical signal from said transmission path;
a test comparison circuit connected to said extraction circuit for determining the optical transmission quality based on the test signal extracted by said extraction circuit, said test comparison circuit further comprising;
a clock extraction circuit for extracting the clock signal from the test signal that is received at the receive end in order to synchronize with the bit rate of the selected test signal;
a descrambler circuit connected to said clock extraction circuit for using the clock component for descrambling the scrambled test signal to generate descrambled signals;
a selector circuit connected to said descrambler unit for selecting one of the descrambled signals from said descrambler circuit; and
a comparison test circuit connected to said selector circuit for performing a test signal comparison and a bit error count/computation of the selected descrambled signal. - View Dependent Claims (2, 3)
- and said optical signal from said optical transmission path is received and wavelength-converted by a receive-end wavelength converter, for regenerating the signal to be transmitted, the optical network system comprising;
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4. An optical transponder in connection with a client line and an optical transmission line, comprising:
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a first optical to electronic (O/E) converter for converting an optical signal from the client line to an electronic signal;
a signal testing unit connected to said first O/E converter for selectively adding a scrambled test signal to the electronic signal so as to generate a test-signal-contained electronic signal, said signal testing unit further comprising;
a clock generator for generating a clock signal indicative of a bit rate of a scrambled test signal to be added to the electronic signal;
an ‘
all 1s and all 0s’
generator circuit for generating ‘
all 1s and all 0s’
signals; and
a scrambler circuit connected to said ‘
all 1s and all 0s’
generator circuit for scrambling the ‘
all 1s and all 0s’
signals to generate the scrambled test signala first electronic to optical (E/O) converter connected to said signal testing unit for converting the test-signal-contained electronic signal to generate a test-signal-contained optical signal to be transmitted in the optical transmission line;
a second optical to electronic (O/E) converter connected to said signal testing unit for converting a received test-signal-contained optical signal from the optical transmission line to a second test-signal-contained electronic signal, wherein said signal testing unit determines the quality of transmission in the optical transmission line based upon the second test-signal-contained electronic signal, said signal testing unit further comprising;
a clock extraction circuit for extracting the clock signal from the second test signal contained electronic signal in order to synchronize with the bit rate of the electronic test signal;
a descrambler circuit connected to said clock extraction circuit for using a clock signal component for descrambling a scrambled test signal component of the second test-signal-contained electronic signal to generate descrambled signals;
a selector circuit connected to said descrambler unit for selecting one of the descrambled signals from said descrambler circuit;
a comparison test circuit connected to said selector circuit for performing a test signal comparison and a bit error count/computation of the selected descrambled signal; and
a second electronic to optical (E/O) converter connected to said signal testing unit for converting the second test-signal-contained electronic signal to generate received optical signal for the client line. - View Dependent Claims (5, 6, 7, 8, 9)
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10. An optical signal network in connection with client lines and an optical network transmission line, a plurality of nodes each connected to a corresponding one of the client lines and the optical network transmission line, the client lines each having an optical signal at a predetermined optical wavelength, the optical network transmission line having an optical signal comprising multiplexed wavelengths, each of said nodes comprising:
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an optical wavelength separator connected to the optical network transmission line for separating a desired wavelength from the optical signal comprising multiplexed wavelengths;
an optical wavelength combiner connected to the client lines and the optical network transmission line for creating the optical signal comprising multiplexed wavelengths; and
a transponder connected to said optical wavelength separator and said optical wavelength combiner for converting an optical signal at a first wavelength to a second wavelength, said transponder further comprising a set of optical-to-electronic converters, electronic-to-optical converters and a transmission quality testing unit connected between an optical-to-electronic converter and an electronic-to-optical converter for testing a transmission quality of the optical network transmission line, said transmission quality testing unit further comprising;
a test signal generator circuit for generating a test signal for testing optical network transmission line quality, said test signal generator circuit further comprising;
a clock generator connected to said test signal generator circuit for generating a clock signal indicative of a bit rate of the test signal from said test signal generator circuit;
an ‘
all 1s and all 0s’
generator circuit for generating ‘
all 1s and 0s’
signals;
a scrambler circuit connected to said ‘
all 1s and all 0s’
generator circuit for scrambling the ‘
all 1s and all 0s’
signals to generate a scrambled test signal;
a test comparison circuit for determining the optical network transmission line quality based on a test signal received from other nodes, said test comparison circuit further comprising;
a clock extraction circuit for extracting a clock signal from a separated wavelength signal in order to determine the bit rate of the separated wave length signal, a descrambler circuit connected to said clock extraction circuit for using the clock signal for descrambling a received scrambled test signal to generate descrambled signals;
a selector circuit connected to said descrambler unit for selecting one of a test signal comparison and a bit error count/computation of a selected descrambled signal. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18)
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19. A method of testing transmission quality in an optical network having optical transmission lines and client lines connected to the optical transmission lines, comprising:
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converting an optical signal at a first wavelength from one of the client lines to an electrical signal in a transponder;
generating a test signal for testing optical transmission line quality;
specifying a bit rate of the test signal by adding a clock signal to a test signal generator;
adding the electrical signal and the test signal in the transponder to create a sum signal;
scrambling the sum signal to generate a scrambled test signal;
converting the scrambled test signal to an optical signal at a second wavelength in the transponder to be transmitted in the optical transmission lines;
converting an optical signal at the second wavelength from the optical transmission lines to a second electrical signal in the transponder;
extracting a clock signal from the second electrical signal;
descrambling the second electrical signal based upon the extracted clock signal to generate descrambled signals;
selecting one of the descrambled signals;
performing a test signal comparison and a bit error count/computation with the selected descrambled signal;
synchronizing the bit rate of the test signal with the clock signal;
determining transmission quality based upon the test signal comparison in the transponder; and
converting the second electrical signal to an optical signal at the first wavelength in the transponder to be outputted to the one of the client lines. - View Dependent Claims (20, 21, 22, 23, 24)
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Specification