JP2003229815A - Device and method for transmitting wavelength multiplexed light, transmitter and receiver - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wavelength multiplex optical transmitting device capable of correcting an error even when there is a failure in a wavelength for an error correction code. <P>SOLUTION: This wavelength multiplex optical transmitting device is provided with a transmitting part 1 having FEC generating parts 21 to 23 for generating an error correction code about an inputted main input data, a MUX part 31 for multiplexing the error correction code with time division, a duplicating part 90 for copying the error correction code subjected to time division multiplexing to two systems, and a wavelength multiplexing part 41 for wavelength-multiplexing and outputting the main signal data and the error correction code subjected to multiplexing with time division of the two systems, and with a receiving part 2 having a wavelength separating part 51 for separating wavelength-multiplexed data, a failure detecting part 61 for detecting a failure in the wavelength of the separated error correction code subjected to time division multiplexing of the two systems, a switching part 71 for selecting a wavelength with no failure when the failure is detected, a DMUX part 72 for separating the selected error correction code subjected to time division multiplexing into an error correction code, and error correcting parts 81 to 83 for correcting an error of the main signal data with the error correction code. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wavelength division multiplexing optical transmission apparatus and method having an error correction function.

[0002]

2. Description of the Related Art In order to cope with the communication volume which is increasing more and more due to the rapid increase in demand for the Internet in recent years, technological development for high speed and large capacity is in progress. To increase capacity, wavelength division multiplexing (WDM: Wavelength)
h Division Multiplexing) The technical development of an optical transmission system is mentioned, and the WDM technology is also used in the submarine cable system which bears international communication. In the submarine cable system, since long-distance transmission is performed, transmission quality is deteriorated due to wavelength dispersion and the like, and bit errors are likely to occur. Therefore, in the submarine cable system, a high-efficiency error correction code FEC (Forward) is used.
It is common to add an Error Correction) for transmission. However, the addition of FEC causes an increase in transmission speed, leading to an increase in system price. Therefore, a method for suppressing an increase in speed due to the addition of FEC by multiplexing FEC on another wavelength and transmitting it is being studied.

FIG. 7 shows, for example, JP-A-11-32008.
It is a figure which shows the conventional apparatus shown by the publication, 1 is a transmission part and 2 is a receiving part in the figure. Transmitter 1
Is a signal transmission circuit 10 that performs transmission processing of an input signal.
A redundant bit generation circuit 20 for generating redundant bits from the input signal, and a redundant bit transmission circuit 30 for transmitting the redundant bits generated by the redundant bit generation circuit 20.
And an optical multiplexing circuit 40 that wavelength-multiplexes the transmission main signal data output from the signal transmission circuit 10 and the transmission redundant bits output from the redundant bit transmission circuit 30. The receiving unit 2 wavelength-separates the signal output from the transmitting unit 1 and separates the received main signal data and the reception redundant bits into an optical demultiplexing circuit 50, and a receiving process of the receiving main signal data output from the optical demultiplexing circuit 50. A signal receiving circuit 60 for performing the following, a redundant bit receiving circuit 70 for receiving the receiving redundant bits output from the optical demultiplexing circuit 50, and a redundant bit for performing error correction on the received main signal data output from the signal receiving circuit 60. It is composed of a processing circuit 80.

Next, the operation will be described. The signal transmission circuit 10 receives the input digital signal (main signal data).
To an optical signal. The redundant bit generation circuit 20 generates redundant bits by error correction coding of the digital signal input to the signal transmission circuit 10. The redundant bit transmission circuit 30 converts the redundant bit generated by the redundant bit generation circuit 20 into an optical signal having a different wavelength from the light converted by the signal transmission circuit 10. The optical multiplexing circuit 40 wavelength-multiplexes the optical signal output from the signal transmitting circuit 10 and the optical signal output from the redundant bit transmitting circuit 30, and transmits the wavelength-multiplexed optical signal. Optical separation circuit 50
Separates an optical signal wavelength-multiplexed and transmitted from the optical multiplexing circuit 40 into an optical signal output from the signal transmitting circuit 10 and an optical signal output from the redundant bit transmitting circuit 30. The signal receiving circuit 60 converts the optical signal output from the signal transmitting circuit 10 into a digital signal. The redundant bit receiving circuit 70 is
The optical signal output from the redundant bit transmission circuit 30 is converted into redundant bits. The redundant bit processing circuit 80 performs error correction of the digital signal output from the signal receiving circuit 60 using the redundant bit output from the redundant bit receiving circuit 70.

Here, as the redundant bit, the above-mentioned F is used.
EC etc. are considered. In FIG. 7, the main signal data has one wavelength, but the WDM technique can be used to expand to multiple wavelengths. FIG. 8 is a diagram showing an outline of a data format of wavelength division multiplex transmission using a conventional FEC. 11 is the first
Corresponding to payload 1 which is the main signal data of
Transmitted in. 12 corresponds to the payload 2, which is the second main signal data, and is transmitted at the wavelength λ2. Reference numeral 13 corresponds to the payload n which is the nth main signal data and is transmitted at the wavelength λn. 11 to 13 are overhead (OH1 to OHn) and check codes (FEC1 to FE) as FEC.
Cn) is added. FIG. 9 is a diagram showing an outline of a data format when the FEC of FIG. 8 is multiplexed with another wavelength and transmitted.

Reference numerals 11 to 13 in FIG. 9 are the main signal data itself without the FEC shown in FIG. Reference numeral 14 corresponds to FEC data, and FEC (overhead (OH1 to OH1 to
OHn) and check codes (FEC1 to FECn)) are multiplexed and transmitted at the wavelength λm. FEC is, for example, I
TU-TG. RS compliant with 975 (255, 23
In the case of using 9), the size is about 7% of the payload, so that 14 wavelengths can be multiplexed. When handling wavelengths exceeding 14 wavelengths, the wavelengths for FEC data may be further increased. Furthermore, in order to improve the error correction capability, F
The size of EC may be increased. For example, in the case of 15%, 6 wavelengths can be multiplexed. When there is an indivisible part (100% -15% x 6 = 10% in the above example)
May match the payload and speed depending on the free space.

[0007]

Since the conventional wavelength division multiplexing optical transmission apparatus is configured as described above, it has the merit of not increasing the speed due to the addition of the error correction code, but the wavelength for the error correction code. Disorders that are biased toward
In the case of a failure such as a disconnection of the optical signal of the error correction code wavelength or a frequent occurrence of bit errors only in the wavelength of the error correction code, a situation occurs in which error correction of the main signal data of all wavelengths cannot be performed. In submarine cable systems that perform distance transmission, it can be said that bit errors in main signal data will always occur, that is, there is a problem in that it is almost impossible to transmit main signal data.

The present invention has been made in order to solve the above problems, and it is possible to transmit main signal data and its error correction code without increasing the speed, and to use the wavelength of the error correction code. An object of the present invention is to obtain a wavelength division multiplexing optical transmission device capable of performing error correction even when there is a failure.

[0009]

A wavelength division multiplexing optical transmission apparatus according to the present invention inputs signal data, generates an error correction code for correcting an error in the input signal data, and generates a plurality of error correction codes. An error correction signal is duplicated, the signal data and the plurality of error correction signals are wavelength-multiplexed to generate wavelength-multiplexed data, and a transmitter that transmits the generated wavelength-multiplexed data, and the wavelength-multiplexed data from the transmitter. Received, signal data and a plurality of error correction signals are acquired from the received wavelength-multiplexed data, an error correction signal having no failure is selected from the acquired plurality of error correction signals, and the selected error correction signal And a receiving unit that corrects an error in the signal data using the above.

The transmission section inputs a plurality of signal data, adjusts timings of the plurality of signal data, and outputs a plurality of timing-adjusted signal data, and the payload processing section inputs. When inputting a plurality of signal data to be input, a plurality of error correction codes generated by the correction code generation unit and the correction code generation unit that generates a plurality of error correction codes for correcting the errors are input to the input signal data. Time-division multiplexing unit that outputs time-division-multiplexed error-correction code by division-division multiplexing, and time-division-multiplexed error-correction code output by the time-division multiplexing unit is copied to a plurality of time-division-multiplexed error-correction codes And a plurality of time-division-multiplexed error correction codes duplicated by the duplication unit and a plurality of signal data output by the payload processing unit. A wavelength multiplexing unit that wavelength-multiplexes the signal data and the plurality of time-division-multiplexed error correction codes to generate wavelength-multiplexed data, and outputs the generated wavelength-multiplexed data. A wavelength demultiplexing unit that inputs the wavelength-division-multiplexed data output by the wavelength-division multiplexing unit, demultiplexes the input wavelength-division-multiplexed data, and obtains the plurality of signal data and the plurality of time-division-multiplexed error correction codes, The plurality of time division multiplexed error correction codes acquired by the wavelength demultiplexing unit are input, and the plurality of time division multiplexed error correction codes that have been input detect a wavelength failure and based on the detected failure. , A failure detection unit that selects a wavelength in which no failure has occurred from the plurality of time-division-multiplexed error correction codes and outputs a selection signal, and the plurality of time-division-multiplexed signals acquired by the wavelength demultiplexer. Error correction code and the selection signal output by the fault detection unit, and based on the input selection signal, one time-division-multiplexed error correction from the input time-division-multiplexed error-correction codes Using a switching unit that selects and outputs a code, a time division separating unit that separates the time-division-multiplexed error correction code output by the switching unit, and a plurality of error correction codes that the time-division separating unit separates An error correction unit that corrects an error in the plurality of signal data output from the wavelength demultiplexing unit is provided.

The transmitting section has a payload processing section for inputting a plurality of signal data, adjusting timing for each of the plurality of signal data, and outputting a plurality of timing-adjusted signal data, and the payload processing section. A plurality of input signal data is input, and a plurality of error correction codes generated by the correction code generation unit and the correction code generation unit that generates a plurality of error correction codes for correcting the errors of the plurality of input signal data are input. Time division multiplexing, input a time division multiplexing error correction code output from the time division multiplexing unit that outputs the time correction multiplexed error correction code, and the time division multiplexing from the time division multiplexing unit, and receive an input of a failure detection signal from the outside, When the fault detection signal is input, the fault information is extracted from the fault detection signal and the fault information is inserted into the time-division-multiplexed error correction code. If the failure information insertion unit to output and the failure detection signal is not input to the failure information insertion unit, one of the plurality of signal data output from the payload processing unit is selected as selection data, and When a fault detection signal is input to the fault information insertion unit, a switching unit that selects the time-division-multiplexed error correction code output from the fault information insertion unit as selection data, and a plurality of units output by the payload processing unit Of the signal data, the time-division-multiplexed error correction code output by the failure information insertion unit, and the wavelength-multiplexed data generated by wavelength-multiplexing the selection data output from the switching unit. And a wavelength multiplexing unit that outputs the wavelength multiplexing data output from the wavelength multiplexing unit of the transmitting unit, and separates the input wavelength multiplexing data. A wavelength demultiplexing unit that acquires the plurality of signal data, the time division multiplexed error correction code, and the selection data, and a failure is detected from the time division multiplexed error correction code acquired by the wavelength demultiplexing unit. The failure detection unit, the time-division multiplexed error correction code and the selection data are input, and when the failure detection unit does not detect a failure, the input time-division multiplexed error correction code is selected, When the fault detection unit detects a fault, a switching unit for selecting the time-division-multiplexed error correction code transmitted as the input selection data, and the time-division-multiplexed error-correction code selected by the switching unit, Using the time division demultiplexing unit that demultiplexes the input time-division-multiplexed error correction code to generate a plurality of error correction codes and the plurality of error correction codes generated by the time division demultiplexer, An error correction unit that corrects an error in the plurality of signal data output from the long separation unit is provided.

Further, the wavelength division multiplexing optical transmission apparatus includes the transmission section and the reception section, the transmission side transmission apparatus for transmitting the wavelength division multiplexing data, the transmission section and the reception section,
A receiving side transmission device for receiving the wavelength division multiplexed data, wherein the receiving part of the receiving side transmission device further inputs the time division multiplexed error correction code acquired by the wavelength demultiplexing part, and inputs the above time. The fault information is extracted from the error-correcting code that has been divided and multiplexed, and the fault information detection unit that outputs the extracted fault information to the switching unit and the fault information insertion unit of the transmission unit of the reception-side transmission device is provided, and the switching unit is The time-division-multiplexed error correction code is selected based on the fault information output from the fault information detection unit, and the fault information insertion unit inputs the fault information from the fault information detection unit. .

A wavelength division multiplexing optical transmission apparatus according to the present invention includes a payload processing section for inputting a plurality of signal data, adjusting timing for each of the plurality of signal data, and outputting a plurality of timing-adjusted signal data. A first error correction code generation unit for inputting a plurality of signal data input by the payload processing unit and generating a plurality of error correction codes for correcting errors of the input plurality of signal data;
A time-division multiplexing unit that time-division-multiplexes the plurality of error-correction codes generated by the first error-correction code generation unit and outputs the time-division-multiplexed error-correction code, and a time-division multiplexing unit that outputs the time-division multiplexing unit. A second error correction code is further generated for the multiplexed error correction code, and the generated second error correction code is added to the time division multiplexed error correction code to generate a double error correction code. The second error correction code generation unit, the plurality of signal data output by the payload processing unit, and the double error correction code output by the second error correction code generation unit are wavelength-multiplexed to generate wavelength multiplexed data. Generated, input the wavelength multiplexing data output by the wavelength multiplexing unit of the transmitter, and a transmitter having a wavelength multiplexing unit that outputs the generated wavelength multiplexing data, separate the input wavelength multiplexing data Signal data and above A wavelength separation unit that acquires a double error correction code, and a second error correction code is extracted from the double error correction code separated by the wavelength separation unit, and time division is performed using the second error correction code. A second error correction unit for correcting an error of the multiplexed error correction code and the time-division multiplexed error correction code corrected by the second error correction unit are time-division separated to obtain a plurality of error correction codes. A time division separation unit to generate,
A reception unit having a first error correction unit that corrects an error in the plurality of signal data output from the wavelength separation unit using the plurality of error correction codes generated by the time division separation unit. It is characterized by

A transmitter according to the present invention inputs signal data, generates an error correction code for correcting an error in the input signal data, duplicates the generated error correction code, and wavelength-multiplexes to a plurality of different wavelengths. The wavelength multiplexing data is generated according to the above, and the generated wavelength multiplexing data is transmitted.

A receiving apparatus according to the present invention receives wavelength-multiplexed data obtained by wavelength-multiplexing signal data and a plurality of error correction signals, acquires signal data and a plurality of error correction signals from the received wavelength-multiplexed data, A feature is that an error correction signal in which no failure has occurred is selected from the plurality of acquired error correction signals, and the error of the signal data is corrected using the selected error correction signal.

The wavelength-division-multiplexed optical transmission method according to the present invention is a wavelength-division-multiplexed optical transmission method in which wavelength-division-multiplexed data is transmitted from a transmitter to a receiver. An error correction code for correcting the error correction code is generated, the generated error correction code is duplicated into a plurality of error correction signals, and the signal data and the plurality of error correction signals are wavelength-multiplexed to generate wavelength-multiplexed data. Transmitting wavelength-multiplexed data, the receiving unit receives the wavelength-multiplexed data from the transmitting unit, obtains signal data and a plurality of error correction signals from the received wavelength-multiplexed data, of the plurality of error correction signals obtained It is characterized in that an error correction signal in which no failure has occurred is selected from the inside, and the error of the signal data is corrected using the selected error correction signal.

The wavelength division multiplexing optical transmission method according to the present invention inputs signal data, generates an error correction code for correcting an error in the input signal data, and duplicates the generated error correction code to a plurality of different wavelengths. It is characterized in that wavelength division multiplexing is performed to generate wavelength division multiplexing data, and the generated wavelength division multiplexing data is transmitted.

A wavelength division multiplexing optical transmission method according to the present invention receives wavelength division multiplexing data obtained by wavelength multiplexing signal data and a plurality of error correction signals, and extracts signal data and a plurality of error correction signals from the received wavelength division multiplexing data. It is characterized in that an error correction signal in which no failure has occurred is selected from the acquired plurality of error correction signals, and the error of the signal data is corrected using the selected error correction signal.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiment 1. Embodiment 1 of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram of a wavelength division multiplexing optical transmission device according to a first embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a transmitter of the wavelength division multiplexing optical transmission apparatus, which is connected to a receiver 2 of the wavelength division multiplexing optical transmission apparatus via an optical fiber 100.

As shown in FIG. 1, the transmitter 1 includes the following components. The payload processing units 11 to 13 perform processing such as timing adjustment on each of the input main signal data. The FEC generators 21 to 23 generate error correction codes for each of the input main signal data. The MUX unit 31 time division multiplexes the error correction codes generated by the FEC generation units 21 to 23.

The duplication unit duplicates the time-division-multiplexed error correction signal output from the MUX unit 31 into a plurality of error correction signals, and outputs the error correction signals to the wavelength multiplexing unit 41. The duplication part corresponds to the part shown by the dotted line in FIG. The number of error correction signals to be duplicated is preferably two when the cost is taken into consideration, but is not limited to two. The wavelength multiplexing unit 41 wavelength-multiplexes the respective main signal data output from the payload processing units 11 to 13 and the time-division-multiplexed error correction code output from the MUX unit 31 and outputs them. The wavelength-multiplexed main signal data and the time-division-multiplexed error correction code are also referred to as wavelength-multiplexed data. Also, the transmitter 1
The time-division-multiplexed error correction code output from the MUX unit 31 is copied into two systems and input to the wavelength multiplexing unit 41.

As shown in FIG. 1, the receiver 2 includes the following components. The wavelength demultiplexing unit 51 demultiplexes the wavelength division multiplexed data input from the transmission unit 1 for each wavelength. Fault detection unit 6
1 detects a fault in the wavelength of the time-division-multiplexed error correction code of the two systems in the data demultiplexed by the wavelength demultiplexer 51. When the fault detecting unit 61 detects a fault, the switching unit 71 selects the wavelength of the fault-free one of the two systems of time-division-multiplexed error correction codes. DM
The UX unit 72 separates the time-division-multiplexed error correction code selected by the switching unit 71 into error correction codes corresponding to the respective main signal data. The error correction units 81 to 83
The error correction code corresponding to each main signal data output from the DMUX unit 72 is used to perform error correction on each main signal data output from the wavelength demultiplexing unit.

The "FEC generator" is also called "correction code generator". Further, the "MUX unit" is a "time division multiplexing unit", the "switching unit" is a "switch unit", and the "DMUX unit".
Is also referred to as a "time division separation unit". Also, "error correction code"
Is also referred to as "FEC data".

This wavelength division multiplexing optical transmission device is premised on that a plurality of signal data are multiplexed and transmitted using a plurality of wavelengths. Therefore, in the transmitting unit 1 shown in FIG. 1, a case in which there are a plurality of payload circuits is shown, but a transmitting unit including only one payload circuit is not excluded. Similarly, although the receiving unit 2 includes a plurality of error correcting units, the receiving unit including only one error correcting unit is not excluded. This wavelength division multiplexing optical transmission device is characterized in that the error correction code is duplicated and transmitted using a plurality of wavelengths.

The main signal data S1, S2, ..., Sn for wavelength multiplexing are input to the transmission unit 1, S1 being the payload processing unit 11 and S2 being the payload processing unit 12 respectively.
In addition, Sn is input to the payload processing unit 13, and processing such as timing adjustment is performed in each payload processing unit. The main signal data S1, S2, ..., Sn are also
S1 is input to the FEC generation unit 21, S2 is input to the FEC generation unit 22, and Sn is input to the FEC generation unit 23.
The generation unit 21 performs the FEC generation of S1 and the FEC generation unit 22.
Then, the FEC generation of S2 and the FEC generation of Sn are performed in the FEC generation unit 23 and output to the MUX unit 31. In the MUX unit 31, the FEC input from each FEC generation unit
Is time-division multiplexed and is output to the wavelength multiplexing unit 41 as one of the wavelength multiplexing data.

Here, the MUX section 31 includes a wavelength multiplexing section 41.
The FEC data is copied and output to. The copying operation indicated by 90 in FIG. 1 is executed.
The wavelength multiplexing unit 41 allocates different wavelengths to the main signal data input from each payload processing unit and the two systems of FEC data input from the MUX unit 31, respectively, performs wavelength multiplexing, and sends out to the optical fiber 100. As a usage pattern of the optical fiber 100, long-distance transmission such as a submarine cable system is assumed. In long-distance transmission, an optical signal is usually transmitted while being amplified by a repeater or the like.

The wavelength-multiplexed data transmitted through the optical fiber 100 is received by the receiving section 2 of the wavelength-multiplexed optical transmission device facing the wavelength-division multiplexed data.
, And the wavelength demultiplexing unit 51 demultiplexes the wavelength division multiplexed data for each wavelength. Of the separated data, two systems of FEC data are input to the failure detection unit 61 and the switching unit 71. The fault detector 61 detects a fault in the wavelength for FEC data transmission. As a failure, a selection signal for judging the failure when an optical input interruption or deviation of FEC overhead detection in FEC data occurs and selecting a wavelength of the two systems of FEC data in which no failure has occurred The (switching signal) is output to the switching unit 71.

The switching section 71 uses this selection signal (switching signal).
Select the non-disturbed wavelength according to
It is output to the X section 72. The DMUX unit 72 separates the time-division-multiplexed FEC data into FECs corresponding to the respective main signal data, and outputs the FEC data to the error correction units corresponding to the respective main signal data. The main signal data S1, S2, ..., Sn output from the wavelength demultiplexing unit 51 are respectively S1.
Is input to the error correction unit 81, S2 is input to the error correction unit 82, Sn is input to the error correction unit 83, and the FEC output from the DMUX unit 72 is used, and the error correction unit 81 performs the error correction of S1. At 82, the error correction unit for S2 is performed, and at the error correction unit 83, error correction for Sn is performed, and the result is output from the reception unit.

FIG. 2 is a diagram showing an outline of a data format between the transmitting unit and the receiving unit in FIG. Reference numeral 11 corresponds to the payload 1 corresponding to the main signal data S1 and flows between the transmitter and the receiver at the wavelength λ1. Reference numeral 12 corresponds to the payload 2 corresponding to the main signal data S2, and flows between the transmitter and the receiver at the wavelength λ2. Reference numeral 13 corresponds to the payload n corresponding to the main signal data Sn, and flows between the transmitter and the receiver at the wavelength λn. Reference numeral 14 corresponds to one of the two systems of FEC data, and flows between the transmitter and the receiver at the wavelength λm. Reference numeral 15 corresponds to another of the two systems of FEC data, and flows between the transmitter and the receiver at the wavelength λx. 14 and 15 are the same data.

As described above, in the first embodiment of the present invention,
The failure detection unit 61 detects a failure such as an optical input cutoff of a wavelength for FEC data transmission or a deviation of FEC overhead detection in the FEC data, and when a failure occurs, the switching unit 71 causes a failure of the two systems of FEC data. Since it is configured to select the wavelength in which the error has not occurred, it is possible to avoid the situation where the error cannot be corrected.

Embodiment 2. The second embodiment of the present invention will be described below with reference to the drawings. FIG. 3 is a block diagram of a wavelength division multiplexing optical transmission device according to a second embodiment of the present invention. In FIG. 3, a transmitter 1, a receiver 2, and an optical fiber 1
00, payload processing unit 11, payload processing unit 12,
Payload processing unit 13, FEC generation unit 21, FEC generation unit 22, FEC generation unit 23, MUX unit 31, wavelength multiplexing unit 41, wavelength demultiplexing unit 51, failure detection unit 61, switching unit 71,
The DMUX unit 72, the error correction unit 81, the error correction unit 82, and the error correction unit 83 have the same configurations as in FIG.

Further, in this embodiment, the following is premised. When starting up the own device or connecting to the opposite device,
Normally, processing such as invalidating the failure information is performed until it stabilizes, and it is considered that the failure information can be obtained from the receiving unit in advance (without failure). The fault information from the receiving unit is the fault information stored in the free area of the FEC data received by the receiving unit, and is used only for switching the transmitting unit. On the other hand, in the fault information insertion in the transmission unit, when a fault (FEC data disconnection, bit error, etc.) is detected on the receiving side of the own device, the transmission unit inserts the fault information to notify the opposite device of the fault. .

When the failure detecting section 61 detects a failure, it outputs a selection signal for selecting the main signal data corresponding to the pre-allocated wavelength to the switching section 71, and the switching section 71
According to this switching signal, main signal data corresponding to the wavelength assigned in advance is selected and output to the DMUX unit 72.
The selection signal is also output to the transmitting unit of the own device as a signal for notifying the opposite device of the failure information. The transmitting unit of the own device and the transmitting unit 1 of the opposite device have the same configuration.

In the second embodiment, the failure is premised on the case where the failure occurs at the 14th wavelength. Therefore, 14
It is premised that the numbered wavelength is in an unusable state. In this embodiment, as an example, a case will be described in which transmission of the main signal data of No. 13 is stopped and FEC data is transmitted at the No. 13 wavelength only when a failure occurs at the No. 14 wavelength. When a failure is detected by the receiving unit, the failure information is transmitted from the transmitting unit of the own device to the opposite device. When the receiving unit of the opposite device detects the failure information, the transmitting unit of the opposite device transmits FEC data for the 13th wavelength. When a failure occurs, the receiving unit uses the FEC for error correction.
The data used is that of the 13th wavelength.

The operation of the transmitting unit of the own device will be described below by replacing it with the transmitting unit 1 of the opposite device. Fault information insertion unit 32
Is the FE output from the MUX unit 31 when the selection signal input from the fault detection unit 61 is the value at the time of fault detection.
The value determined as the failure information is inserted into the empty area in the C data and output to the wavelength multiplexing unit 41. Wavelength multiplexer 41
Of the data output from the FEC data, the wavelength for FEC data is transmitted to the receiving unit of the opposite device in a form including the failure information. The receiving unit of the opposite device and the receiving unit 2 of the own device have the same configuration.

The operation of the receiving unit of the opposite device will be described below by replacing it with the receiving unit 2 of the own device. Of the data separated and output from the wavelength separation unit 51, the FEC data is input to the failure detection unit 61, the switching unit 71, and the failure information detection unit 62. The fault information detection unit 62 detects the fault information inserted in the empty area in the FEC data, and when the fault information is detected, outputs the fault information to the transmission unit 1. In the transmission unit 1, the failure information input from the reception unit is input to the switching unit 33, and when the failure information is input, the switching unit 33 deselects the main signal data output from the payload processing unit 13,
The FEC data output from the failure information insertion unit 32 is selected. Among the data output from the wavelength multiplexing unit 41, the FEC data is transmitted to the receiving unit 2 via the optical fiber 100 for the wavelength corresponding to the payload processing unit 13.

Since the switching section 71 has already selected the wavelength for payload according to the switching signal, the DMUX section 72 is selected.
The FEC data transmitted at the wavelength corresponding to the payload processing unit 13 is output to. Error correction units 81-83
Then, error correction is performed using this FEC data. However, F is input to the error correction unit 83 when a failure is detected.
Since it is EC data, the main signal data Sn is detected when a failure is detected.
Is not conducted.

FIG. 4 is a diagram showing an outline of the data format between the transmitting unit and the receiving unit in FIG. Reference numeral 11 corresponds to the payload 1 corresponding to the main signal data S1 and flows between the transmitter and the receiver at the wavelength λ1. Reference numeral 12 corresponds to the payload 2 corresponding to the main signal data S2, and flows between the transmitter and the receiver at the wavelength λ2. Reference numeral 13 corresponds to the payload n corresponding to the main signal data Sn, and flows between the transmitter and the receiver at the wavelength λn. Reference numeral 14 corresponds to FEC data and flows between the transmitter and the receiver at the wavelength λm. Fault information is inserted into the empty area of the FEC data and transmitted. When failure information is detected by the receiving unit, 13 is the main signal data Sn to 14
The same FEC data as the above is switched to flow between the transmitter and the receiver.

As described above, in the second embodiment of the present invention,
The failure detection unit 61 detects a failure such as an interruption of the optical input of the wavelength for FEC data transmission or deviation of the FEC overhead detection in the FEC data, and when a failure occurs, the failure information is inserted by the failure information insertion unit 32 of the own device. Then transmit to the opposite device,
The fault information detection unit 62 of the opposite device detects fault information,
Since the switching unit 33 switches the main signal data Sn to the FEC data and transmits the FEC data to the opposite device, and the switching unit 71 of the opposite device selects the FEC data, it is possible to avoid a situation in which error correction cannot be performed.

As described above, the wavelength division multiplexing optical transmission apparatus of this embodiment includes a payload processing section for performing processing such as timing adjustment for each input main signal data,
A failure detection signal is input from an FEC generation unit that generates an error correction code for each of the input main signal data, a MUX unit that time-division-multiplexes the error correction code generated by the FEC generation unit, and a reception unit. And a failure information insertion section for inserting failure information into the time-division multiplexed error correction code output from the MUX section, and respective main signals output from the payload processing section when failure information is not input from the receiving section When main signal data corresponding to a pre-allocated wavelength of data is selected and fault information is input from the receiving unit, the time division multiplexed error after the fault information insertion output from the fault information inserting unit is input. A switching unit for selecting a correction code, main signal data output from the payload processing unit, and time division multiplexing output from the fault information insertion unit. And a wavelength division multiplexing data input from the transmission section, and a wavelength multiplexing section for wavelength-multiplexing and outputting the error correction code and the main signal data output from the switching section or the time-division-multiplexed error correction code. From the fault information insertion unit, and a wavelength demultiplexing unit that demultiplexes each wavelength, out of the data demultiplexed by the wavelength demultiplexing unit, a fault detection unit that performs fault detection of the wavelength of the time-division-multiplexed error correction code, and the fault information insertion unit. A fault information detection unit that detects fault information from the output time-division-multiplexed error correction code after the fault information is inserted,
When a failure is detected by the failure detection unit, main signal data corresponding to a pre-allocated wavelength of the respective main signal data output from the payload processing unit is deselected, and the switching unit of the transmission unit A switching unit for selecting the selected time-division multiplexed error correction code, and a DM for separating the time-division multiplexed error correction code selected by the switching unit into error correction codes corresponding to the respective main signal data.
Receiving section having a UX section and an error correcting section for performing error correction of the respective main signal data output from the wavelength demultiplexing section by an error correction code corresponding to the respective main signal data output from the DMUX section. It is characterized by having.

Embodiment 3. The third embodiment of the present invention will be described below with reference to the drawings. FIG. 5 is a block diagram of a wavelength division multiplexing optical transmission device according to a third embodiment of the present invention. In FIG. 5, a transmitter 1, a receiver 2, and an optical fiber 1
00, payload processing unit 11, payload processing unit 12,
Payload processing unit 13, FEC generation unit 21, FEC generation unit 22, FEC generation unit 23, MUX unit 31, wavelength multiplexing unit 41, wavelength demultiplexing unit 51, DMUX unit 72, error correction unit 8
1, the error correction unit 82 and the error correction unit 83 have the same configurations as those in FIG.

The FEC generation unit 34 further generates and adds FEC to the FEC data output from the MUX unit 31, and outputs the FEC data to the wavelength multiplexing unit 41. Of the data output from the wavelength multiplexing unit 41, the FEC data wavelength is transmitted to the receiving unit of the opposite device in a form including the generated FEC. Of the data separated and output from the wavelength separation unit 51, the FEC data is input to the error correction unit 63. In the error correction unit 63, the FE generated and added by the FEC generation unit 34
Using C, the FEC data output from the MUX unit 31 is error-corrected and output to the DMUX unit 72.

FIG. 6 is a diagram showing an outline of the data format between the transmitting unit and the receiving unit in FIG. Reference numeral 11 corresponds to the payload 1 corresponding to the main signal data S1 and flows between the transmitter and the receiver at the wavelength λ1. Reference numeral 12 corresponds to the payload 2 corresponding to the main signal data S2, and flows between the transmitter and the receiver at the wavelength λ2. Reference numeral 13 corresponds to the payload n corresponding to the main signal data Sn, and flows between the transmitter and the receiver at the wavelength λn. Reference numeral 14 corresponds to FEC data and flows between the transmitter and the receiver at the wavelength λm. 14, FEC data is generated and added to the FEC data for S1 to Sn and transmitted.

As described above, in the third embodiment of the present invention,
The FEC data output from the MUX unit 31 is further configured to generate and add FEC in the FEC generation unit 34, and the error correction unit 63 performs error correction of the FEC data output from the MUX unit 31. Even if the bit error rate of the data wavelength is high, it is possible to avoid the situation where the error of the main signal data cannot be corrected. In the third embodiment of the present invention, it is not possible to avoid a serious failure such as light interruption as in the first and second embodiments of the present invention, but it is possible to avoid a bit error failure.

As described above, the wavelength division multiplexing optical transmission apparatus of this embodiment has a payload processing section for performing processing such as timing adjustment for each input main signal data,
An FEC generation unit that generates an error correction code for each of the input main signal data, a MUX unit that time-division-multiplexes the error correction code generated by the FEC generation unit, and a time-division multiplexing output from the MUX unit. An FEC generation unit that further generates an error correction code for the generated error correction code, each main signal data output from the payload processing unit, and an FEC that further generates the error correction code.
A transmitter having a wavelength multiplexer that wavelength-multiplexes and outputs the time-division-multiplexed error correction code output from the generator, and a wavelength demultiplexer that demultiplexes the wavelength-multiplexed data input from the transmitter for each wavelength. An error correction unit that performs an error correction of the data generated by the further error correction code among the data separated by the wavelength separation unit, and a time division multiplexed error correction code output from the error correction unit. DMU for separating into error correction codes corresponding to the respective main signal data
A reception unit having an X unit and an error correction unit that performs error correction of the respective main signal data output from the wavelength demultiplexing unit by an error correction code corresponding to each main signal data output from the DMUX unit. It is characterized by having.

Fourth Embodiment In the first embodiment, the case where two systems of time-division-multiplexed error correction codes are generated has been described. However, the present invention is not limited to the case of two-systems, and is a case of generating a plurality of time-division-multiplexed error correction codes. May be.
In this case, it is necessary to make a correspondence between the plurality of time division multiplexed error correction codes and the switching unit, and a correspondence between the wavelength multiplexing unit and the wavelength demultiplexing unit. However, it is desirable in terms of cost and the like to duplicate the time-division-multiplexed error correction code in two and use the duplicated two time-division-multiplexed error correction codes.

Further, the procedure for copying and transmitting the time-division-multiplexed error correction code has been described in the first and second embodiments, but the procedure is not limited to these. It is also possible to transmit a plurality of time division multiplexed error correction codes by a procedure other than the above.

[0048]

According to the wavelength division multiplexing optical transmission apparatus and method of the present invention, the reliability is improved by duplicating the error correction code and wavelength-multiplexing the duplicated error correction codes to a plurality of wavelengths for transmission. You can

Further, reliability can be improved by acquiring a plurality of error correction codes from the transmitted wavelength-multiplexed data and selecting an error correction code having no failure from the acquired plurality of error correction codes. it can.

The wavelength-division-multiplexed optical transmission apparatus and method can avoid that error correction cannot be performed by preparing a plurality of wavelengths for transferring the error correction code.

Further, the wavelength division multiplexing optical transmission apparatus and method are
When a failure occurs, one wavelength is used as a wavelength for transmitting an error correction code, and when no failure occurs, it is used as a wavelength for transmitting signal data, thereby transmitting a plurality of error correction codes when a failure occurs. This makes it possible to avoid that error correction cannot be performed.

Further, by duplicating the error correction code, it is possible to avoid that the error cannot be corrected.

The wavelength division multiplexing optical transmission apparatus and method transmits an error correction code even at another wavelength, transmits an error correction code at a wavelength of a part of main signal data, and further adds an error correction code to the error correction code data. By adding the error correction code, even if there is a failure in the wavelength for transmitting the error correction code, it can be relieved.

[Brief description of drawings]

FIG. 1 is a block diagram showing a wavelength division multiplexing optical transmission device according to a first embodiment of the present invention.

FIG. 2 is a diagram showing an outline of a data format between a transmission unit and a reception unit in FIG.

FIG. 3 is a block diagram showing a wavelength division multiplexing optical transmission device according to a second embodiment of the present invention.

FIG. 4 is a diagram showing an outline of a data format between a transmission unit and a reception unit in FIG.

FIG. 5 is a block diagram showing a wavelength division multiplexing optical transmission device according to a third embodiment of the present invention.

6 is a diagram showing an outline of a data format between a transmission unit and a reception unit in FIG.

FIG. 7 is a block diagram showing a conventional wavelength division multiplexing optical transmission device.

8 is a diagram showing an outline of a data format between a transmission unit and a reception unit in FIG.

9 is a diagram showing an outline of a data format between a transmission unit and a reception unit when the FEC of FIG. 8 is multiplexed with another wavelength.

[Explanation of symbols]

1 transmitter, 2 receiver, 10 signal transmitter, 11
Payload processing unit, 12 payload processing unit, 13 payload processing unit, 20 redundant bit generation circuit, 21 F
EC generation unit, 22 FEC generation unit, 23 FEC generation unit, 30 redundant bit transmission circuit, 31 MUX unit, 32
Failure information insertion unit, 33 switching unit, 34 FEC generation unit,
40 optical multiplexing circuit, 41 wavelength multiplexing section, 50 optical demultiplexing circuit, 51 wavelength demultiplexing section, 60 signal receiving circuit, 61 failure detecting section, 62 failure information detecting section, 70 redundant bit receiving circuit, 71 switching section, 72 DMUX section, 80 redundant bit processing circuit, 81 error correction unit, 82 error correction unit,
83 error correction section, 90 replication section, 100 optical fiber.

Claims (10)

[Claims] 1. Signal data is input, an error correction code for correcting an error in the input signal data is generated, the generated error correction code is duplicated into a plurality of error correction signals, and the signal data and the plurality of errors are generated. A wavelength division multiplex of a correction signal to generate wavelength division multiplex data, a transmitter that transmits the generated wavelength division multiplex data, a wavelength division multiplex data received from the transmitter, and signal data and a plurality of errors from the received wavelength division multiplex data. A correction signal and a receiving unit that selects an error correction signal in which no failure has occurred from the acquired plurality of error correction signals, and corrects the error in the signal data using the selected error correction signal. A wavelength division multiplexing optical transmission device comprising: 2. The payload processing section, wherein the transmission section receives a plurality of signal data, adjusts timings of the plurality of signal data, and outputs the plurality of timing-adjusted signal data, and the payload processing section. A plurality of error correction codes generated by the correction code generation unit, which inputs a plurality of signal data input by the Time-division-multiplexing the time-division-multiplexed signal and outputting the time-division-multiplexed error correction code, and the time-division-multiplexed error-correction code output by the time-division multiplexing unit. The duplication unit to be duplicated, the plurality of signal data output from the payload processing unit, and the plurality of time division multiplexed error correction codes duplicated by the duplication unit are input, and The number of signal data and the plurality of time division multiplexed error correction codes are wavelength-multiplexed to generate wavelength-multiplexed data, and the wavelength-multiplexing unit that outputs the generated wavelength-multiplexed data is provided. A wavelength demultiplexing unit for inputting the wavelength multiplexing data output from the wavelength multiplexing unit of the transmitting unit and separating the input wavelength multiplexing data to obtain the plurality of signal data and the plurality of time division multiplexed error correction codes. And inputting the plurality of time division multiplexed error correction codes acquired by the wavelength demultiplexing unit, detecting the wavelength failure for the plurality of input time division multiplexed error correction codes, and detecting the detected failure. Based on the plurality of time division multiplexed error correction codes, a fault detection unit that selects a wavelength in which no fault has occurred and outputs a selection signal, and the plurality of time division multiplexing units acquired by the wavelength demultiplexing unit Error correction code and the selection signal output by the failure detection unit are input, and based on the input selection signal, one of the input time correction multiplexed error correction codes is time-division multiplexed. A switching unit that selects and outputs an error correction code, a time division separation unit that separates the time division multiplexed error correction code output by the switching unit, and a plurality of error correction codes that the time division separation unit separates The wavelength division multiplexing optical transmission device according to claim 1, further comprising: an error correction unit that corrects an error in the plurality of signal data output from the wavelength demultiplexing unit. 3. The payload processing section, wherein the transmission section inputs a plurality of signal data, adjusts timing of each of the plurality of signal data, and outputs a plurality of timing-adjusted signal data, and the payload processing. A plurality of signal data input by the unit, and a plurality of error correction codes generated by the correction code generation unit that generates a plurality of error correction codes that correct errors in the plurality of input signal data The time-division-multiplexed code is output, and the time-division-multiplexing unit that outputs the time-division-multiplexed error correction code and the time-division-multiplexed error-correction code are input from the time-division multiplexing unit, and the failure detection signal is input from the outside. When the fault detection signal is received and the fault information is input, the fault information is extracted from the fault detection signal and the fault information is inserted into the time-division multiplexed error correction code. If the failure detection signal is not input to the failure information insertion unit that outputs the error information and the failure information insertion unit, one of the plurality of signal data output from the payload processing unit is selected as selection data. When the fault detection signal is input to the fault information insertion unit, the switching unit that selects the time-division-multiplexed error correction code output from the fault information insertion unit as selection data, and the payload processing unit outputs Multiple signal data,
Wavelength multiplex for generating wavelength multiplexed data by wavelength-multiplexing the time-division-multiplexed error correction code output by the failure information insertion unit and the selection data output from the switching unit, and outputting the generated wavelength multiplexed data. The receiver receives the wavelength-multiplexed data output from the wavelength-multiplexer of the transmitter, separates the input wavelength-multiplexed data into the plurality of signal data, and the time-division-multiplexed error. A wavelength demultiplexing unit that acquires a correction code and the selected data, a failure detection unit that detects a failure from the time division multiplexed error correction code acquired by the wavelength demultiplexing unit, and the time division multiplexed error correction When the code and the selection data are input and the failure detection unit does not detect a failure, the input time-division-multiplexed error correction code is selected, and when the failure detection unit detects a failure, input A switching unit for selecting the time-division-multiplexed error correction code transmitted as the selected data and the time-division-multiplexed error-correction code selected by the switching unit are input, and the input time-division-multiplexed error correction is input. Using the time division demultiplexing unit that separates the codes to generate a plurality of error correction codes and the plurality of error correction codes generated by the time division demultiplexing unit, the plurality of signal data output from the wavelength demultiplexing unit The wavelength division multiplexing optical transmission device according to claim 1, further comprising: an error correction unit that corrects an error. 4. A wavelength division multiplexing optical transmission apparatus comprising: the transmission section and the reception section; a transmission side transmission apparatus for transmitting the wavelength division multiplexing data; and the transmission section and the reception section. A receiving side transmission device for receiving data, wherein the receiving part of the receiving side transmission device further inputs the time division multiplexed error correction code acquired by the wavelength demultiplexing part,
Fault information is extracted from the input time-division-multiplexed error correction code, and the extracted fault information includes a fault information detection unit that outputs the fault information to the switching unit and the fault information insertion unit of the transmission unit of the reception-side transmission device, The switching unit selects the time-division multiplexed error correction code based on the fault information output from the fault information detection unit, and the fault information insertion unit inputs the fault information from the fault information detection unit. The wavelength division multiplexing optical transmission device according to claim 3. 5. A payload processing section for inputting a plurality of signal data, adjusting timing for each of the plurality of signal data, and outputting a plurality of timing-adjusted signal data, and a plurality of payload processing sections input by the payload processing section. A first error correction code generation unit for inputting the signal data of No. 1 and generating a plurality of error correction codes for correcting the errors of the plurality of input signal data, and a plurality of plural error correction code generation units generated by the first error correction code generation unit. A second error is added to the time division multiplexing unit that time-division-multiplexes the error correction code and outputs the time-division-multiplexed error correction code, and the time-division-multiplexed error correction code output from the time-division multiplexing unit. A second error correction code generation unit that generates a correction code and adds the generated second error correction code to the time-division multiplexed error correction code to generate a double error correction code; A plurality of signal data payload processing unit is outputted,
A transmitter having a wavelength multiplexer that wavelength-multiplexes the double error correction code output from the second error correction code generator to generate wavelength multiplexed data and outputs the generated wavelength multiplexed data; Wavelength division data output by the wavelength division multiplexing unit of the section, a wavelength separation unit for separating the input wavelength division multiplexing data to obtain the plurality of signal data and the double error correction code, and the wavelength separation unit A second error correction code that extracts a second error correction code from the separated double error correction code and corrects the error of the time-division-multiplexed error correction code using the second error correction code; A time division demultiplexing unit that time division demultiplexes the time correction demultiplexed error correction code corrected by the second error correction unit to generate a plurality of error correction codes; and a plurality of time division demultiplexers generated by the time division demultiplexing unit. Using the error correction code, the above wavelength A wavelength division multiplexing optical transmission device comprising: a receiving unit having a first error correction unit that corrects an error with respect to the plurality of signal data output from the demultiplexing unit. 6. Wavelength multiplexed data is generated by inputting signal data, generating an error correction code for correcting an error in the input signal data, duplicating the generated error correction code, and wavelength-multiplexing to a plurality of different wavelengths. And transmitting the generated wavelength-multiplexed data. 7. Wavelength multiplexed data obtained by wavelength-multiplexing signal data and a plurality of error correction signals is received, signal data and a plurality of error correction signals are acquired from the received wavelength multiplexed data, and a plurality of acquired error corrections are performed. A receiving apparatus, characterized in that an error correction signal in which no failure has occurred is selected from the signals, and the error of the signal data is corrected using the selected error correction signal. 8. A WDM optical transmission method for transmitting WDM data from a transmitter to a receiver, wherein the transmitter inputs signal data and generates an error correction code for correcting an error in the input signal data. , The generated error correction code is duplicated into a plurality of error correction signals, the signal data and the plurality of error correction signals are wavelength-multiplexed to generate wavelength multiplexed data, and the generated wavelength multiplexed data is transmitted, and the received signal is received. The unit receives the wavelength-multiplexed data from the transmission unit, acquires signal data and a plurality of error correction signals from the received wavelength-multiplexed data, and acquires an error in which no failure has occurred from the acquired plurality of error correction signals. A wavelength division multiplexing optical transmission method comprising selecting a correction signal and correcting the error of the signal data using the selected error correction signal. 9. Inputting signal data, generating an error correction code for correcting an error of the input signal data, duplicating the generated error correction code and wavelength-multiplexing to a plurality of different wavelengths to generate wavelength-multiplexed data. And transmitting the generated wavelength-division-multiplexed data. 10. Wavelength multiplexed data obtained by wavelength-multiplexing signal data and a plurality of error correction signals is received, signal data and a plurality of error correction signals are acquired from the received wavelength multiplexed data, and a plurality of acquired error corrections are performed. A wavelength division multiplexing optical transmission method characterized in that an error correction signal in which no failure has occurred is selected from the signals and the error of the signal data is corrected using the selected error correction signal.