JP6501968B2 - Transmission system - Google Patents

Description

  The present invention relates to a transmission system, and more particularly to a transmission system including a plurality of transponders that perform transmission using an optical fiber.

  BACKGROUND Conventionally, a transmission system using a transponder has been used. In such a transmission system, when transmitting a signal from a customer transmission apparatus, a network path in which transponders are connected in multiple stages between a plurality of stations is constructed.

  Since the transponders installed in the station are in-station communication between the transponders, XFP (10 Gigabit Small Form-Factor Pluggable), SFP + (Small Form-Factor Pluggable Plus), and CFP (100 G Form-Factor Pluggable) Etc. are used. The types of signals between the customer transmission device and the transponder include SDH (Synchronous Digital Hierarchy), Ethernet (registered trademark), OTN (Optical Transport Network), etc. The transmission rate is also 10 Gbps, 40 Gbps and 100 Gbps, etc. There are a mix of different types of rates.

When constructing a network path, it is common for the transmission rate of the transponder to be the same as the transmission rate of the customer transmission device. If, during operation of the network path, the transmission rate of the signal output from the customer transmission device to the transponder is changed, the change may cause problems in the connection between the transponders.
Even in such a case, the transponder in the station can cope with the change of the transmission rate only by replacing the transponder connected to the customer transmission apparatus by dividing the signal into a plurality of lanes and transmitting it. There is a case.

  For example, when the signal from the customer transmission device changes from 100 Gbps signal to 10 Gbps signal, the transponder at the termination point connected with the customer transmission device is changed to a transponder compatible with 10 Gbps client interface, The transponder can cope with such a change by using OTU4 for the client interface. OTU4 is an ITU-T (International Telecommunication Union Telecommunication Standardization Sector) Recommendation G.3. As defined in 709, ten 10 Gbps signals can be accommodated, and 10 Gbps signals can be transmitted transparently.

  Here, as a technique for transmitting a signal by dividing it into a plurality of lanes, G.I. There is a technology that uses OTL 4.10. Defined in 709 annex C. The OTL 4.10 divides the 10 G signal into units and transmits the OTU 4 signal so that a Frame alignment signal (FAS) for detecting frame synchronization is at the head. Further, in the system described in Patent Document 1, data capable of lane identification is inserted in the FAS region, and a signal is divided into arbitrary lanes.

JP, 2011-223454, A

  However, even if OTU4 changes a path operated by a client interface compatible with 10 Gbps to a client interface compatible with 100 Gbps, all transponders on the path are 100 Gbps in order to transmit 100 Gbps signals transparently. It is necessary to change to the transponder for the client.

  Also, when the network path being operated is changed to a client interface of a rate different from that of operation, G. When an OTL defined in 709 annex C is used, a circuit having a huge memory is required to receive 20 OTU frames and correct the delay amount. Also in the system described in Patent Document 1, in order to combine signals of different rates, a circuit having a huge memory is required.

  Therefore, an object of the present invention is to make it possible to divide and transmit a signal using a plurality of optical fibers in response to a change in transmission rate with a relatively small memory.

  A transmission system according to a first aspect of the present invention is a first transponder receiving data of a particular type transmitted at a first transmission rate, and m (m is an integer of 2 or more) optical fibers A transmission system including a second transponder connected to the first transponder, the first transponder receiving a particular type of data transmitted at the first transmission rate , A first signal conversion unit that generates an OTU frame storing data of a specific format received by the first reception unit, and the OTU frame generated by the first signal conversion unit The FEC data is deleted from the table and divided into m storage frames determined in advance in the column direction, and in each of the m storage frames, an area from which the FEC data is deleted is A first signal processing unit that generates m divided frames by adding skew information indicating the arrangement position of each of the m storage frames in the TU frame; and the first signal processing unit generates A first transmission unit for transmitting each of the m divided frames at a second transmission rate from each of the m optical fibers to the second transponder, wherein the second transponder is configured to: A second receiving unit for receiving each of the m divided frames transmitted from the first transmission unit from each of the m optical fibers, and m divided receptions received by the second receiving unit A second signal processing unit that generates a frame obtained by combining each of the m divided frames received by the second receiving unit with reference to skew information included in each of the frames; Signal processing unit A second signal conversion unit for extracting data of the specific format from the generated frame; and data of the specific format extracted by the second signal conversion unit at the first transmission rate And 2 transmitters.

A transmission system according to a second aspect of the present invention is a first transponder receiving data of a specific type transmitted at a first transmission rate, and m (m is an integer of 2 or more) optical fibers A transmission system including a second transponder connected to the first transponder, the first transponder receiving a particular type of data transmitted at the first transmission rate , A first signal conversion unit that generates an OTU frame storing data of a specific format received by the first reception unit, and the OTU frame generated by the first signal conversion unit and in the column direction, divided into m storage frame predetermined end of each of the m pieces of storing the frame, new, each of the m pieces of storing the frame in the OTU frame The first signal processing unit that generates m divided frames by adding skew information indicating the array position, and each of the m divided frames generated by the first signal processing unit are A first transmission unit for transmitting data from each of the m optical fibers to the second transponder at a transmission rate of m, and the second transponders include m transmissions from the first transmission unit. And a second receiving unit that receives each of the m divided optical fibers from each of the m optical fibers, and skew information included in each of the m divided frames received by the second receiving unit. And a second signal processing unit that generates an OTU frame by combining each of the m divided frames received by the second receiving unit; and an OTU frame generated by the second signal processing unit. Correct the error A second signal conversion unit for extracting data of the specific format from the OTU frame generated by the second signal processing unit, and a specific format of the second format converted by the second signal conversion unit. And a second transmission unit that transmits data at the first transmission rate.

  According to one aspect of the present invention, since skew information indicating an arrangement position in the OTU frame is added to each divided frame divided based on the OTU frame, the transmission rate can be changed with a relatively small memory. Correspondingly, signals can be split and transmitted using multiple optical fibers.

It is a schematic diagram of the transmission system concerning Embodiment 1-4. FIG. 2 is a block diagram schematically showing a configuration of a transponder in the first and second embodiments. ITU-T recommendation G. FIG. 10 is a schematic view showing a frame shape defined in 709. FIG. 2 is a block diagram schematically showing a configuration of a signal processing unit in Embodiments 1 and 2. FIG. 7 is a schematic diagram for explaining processing in a data division unit in the first embodiment. FIG. 5 is a schematic diagram for explaining a divided frame in the first embodiment. FIG. 2 is a block diagram showing an example of a hardware configuration of a transponder in the first embodiment. FIG. 16 is a schematic diagram for explaining a divided frame in Embodiment 2; FIG. 18 is a block diagram schematically showing a configuration of a signal processing unit in Embodiments 3 and 4. FIG. 16 is a schematic diagram for explaining a divided frame in the third embodiment. FIG. 16 is a block diagram schematically showing a configuration of a transponder in a fourth embodiment. FIG. 16 is a schematic diagram for explaining a divided frame and a skew information frame in the fourth embodiment.

Embodiment 1
FIG. 1 is a schematic diagram of a transmission system 100 according to the first embodiment.
The transmission system 100 comprises a customer transmission device 110, a transponder 120, a transponder 130, a transponder 140, a transponder 150, and a customer transmission device 160.

The signal transmitted from the customer transmitter 110 is input to the transponder 120 and output from the transponder 120 to the outside of the station.
The signal input to the transponder 130 is output to the transponder 140 by in-station communication.
The signal input to the transponder 140 is output to the transponder 150 by the out-of-station communication.
The signal input to the transponder 150 is output to the customer transmitter 160.
Communication from the customer delivery device 110 to the customer delivery device 160 occurs over the network path 170.

Although the transponder 130 is connected to the transponder 120 connected to the customer transmission apparatus 110, the connection destination of the transponder 130 is not limited to such an example. For example, the transponder 130 may be connected to another intra-station communication transponder capable of performing an out-of-station communication.
Moreover, although the transponder 140 is connected to the transponder 150 connected to the customer transmitter 160, the connection destination of the transponder 140 is not limited to such an example. For example, the transponder 140 may be connected to a transponder performing other in-station communication that can perform out-of-station communication.
By performing such connection, it is possible to connect relay devices for branching or inserting signals between the customer transmission device 110 and the customer transmission device 160 in multiple stages. In FIG. 1, the transponder 130 and the transponder 140 constitute such a relay device.

FIG. 2 is a block diagram schematically showing the configuration of transponder 130 and transponder 140. Referring to FIG.
The transponder 130 and the transponder 140 are connected by m (m is an integer of 2 or more) optical fibers 101 # 1 to 101 # m.
The first embodiment shows an example of transmitting a signal from the transponder 130 to the transponder 140. Here, the transmitting transponder 130 is also referred to as a first transponder, and the receiving transponder 140 is also referred to as a second transponder.

The transponder 130 includes an external I / F unit 131, a signal conversion unit 132, a signal processing unit 133, and a communication I / F unit 134.
The external I / F unit 131 is an interface that performs external communication. Here, the external I / F unit 131 receives an optical signal sent from the transponder 120 at a transmission rate of k Gbps, and the specific type (first type) used in the external communication. Convert data into electrical signals. Here, k is an arbitrary predetermined number. Here, the transmission rate of k Gbps is also referred to as a first transmission rate. In other words, the station-oriented I / F unit 131 functions as a first receiving unit that receives data of a specific format transmitted at a first transmission rate.

The signal conversion unit 132 stores the data indicated by the electrical signal supplied from the station-directed I / F unit 131 in data of a data format (second format) for transmitting at a transmission rate of n Gbps. , And a first signal conversion unit that generates data for transmission at a transmission rate of n Gbps. Here, n is an arbitrary predetermined number. Here, the transmission rate of n Gbps is also referred to as a second transmission rate.
For example, the signal conversion unit 132 is configured to transmit data indicated by an electrical signal transmitted from the external I / F unit 131 according to ITU-T Recommendation G.3. By storing in the payload of the frame shape of OTU by 709, the OTU frame which is data for transmitting with the transmission rate of nGbps is generated.

FIG. 3 shows ITU-T Recommendation G.3. FIG. 10 is a schematic view showing a frame shape defined in 709.
As shown in FIG. 3, the OTU frame 10 includes an area R1 for storing the OTU / ODU overhead 11, an area R2 for storing the payload 12, and an area R3 for storing the FEC data 13. And.
The OTU / ODU overhead 11 is data including frame synchronization information, performance information, and monitoring information.
The payload 12 is data to be transmitted.
The FEC data 13 is Forward Error Correction (FEC) data for performing error correction when an error occurs.

  The signal processing unit 133 illustrated in FIG. 2 processes the OTU frame generated by the signal conversion unit 132 to generate a first signal that generates m divided frames for transmission at an n Gbps transmission rate. It is a processing unit. For example, the signal processing unit 133 deletes the FEC data from the OTU frame generated by the signal conversion unit 132, and divides the OTU frame into m storage frames determined in advance in the column direction. Then, the signal processing unit 133 adds the skew information indicating the arrangement position of each of the m storage frames in the OTU frame to the area in which the FEC data is deleted in each of the m storage frames, thereby m Generate divided frames.

FIG. 4 is a block diagram schematically showing the configuration of the signal processing unit 133. As shown in FIG.
The signal processing unit 133 includes an FEC data deletion unit 133 a, a data division unit 133 b, and a skew information addition unit 133 c.
The FEC data deleting unit 133 a deletes the FEC data 183 in the OTU frame 10 supplied from the signal converting unit 132. Then, the frame after deletion is given to the data dividing unit 133 b.

The data division unit 133 b divides the frame received from the FEC data deletion unit 133 a into m storage frames determined in advance.
FIG. 5 is a schematic diagram for explaining the processing in the data division unit 133 b.
As shown in FIG. 5, the data dividing unit 133 b divides the frame 20 received from the FEC data deleting unit 133 a into m frames determined in advance in the column direction, thereby storing the storage frame. Generate The storage frame divided here is in a data format for transmission at an n Gbps transmission rate.

The skew information addition unit 133c illustrated in FIG. 4 stores each of the storage frames generated by the data division unit 133b in an area where the FEC data deleted by the FEC data deletion unit 133a is stored. A divided frame is generated by adding skew information to indicate the arrangement position of the frame. The skew information is a number indicating the arrangement position in the frame 20 for each storage frame.
FIG. 6 is a schematic diagram for explaining a divided frame.
As shown in FIG. 6, skew information is added to each of the divided frames in the area where the FEC data 183 is stored in the OTU frame 10.

Communication I / F section 134 shown in FIG. 2 converts the m divided frames subjected to frame processing into m optical signals, and each of m optical signals is connected to m optical fibers 101 # 1. Functions as a first transmission unit that transmits to each of the transponders 140 to 101 # m.
For example, the communication I / F unit 134 includes m client modules 135 # 1 to 135 # m that convert each of the m divided frames into an optical signal.

Next, the transponder 140 on the receiving side will be described.
As shown in FIG. 2, the transponder 140 includes a communication I / F unit 141, a signal processing unit 143, a signal conversion unit 144, and an I / F unit 145 for the outside of the office.
The communication I / F unit 141 receives each of the m optical signals from each of the m optical fibers 101 # 1 to 101 # m, and converts the m optical signals into m divided frames. , And m are second receiving units for receiving divided frames. This divided frame is in a data format for transmission at n Gbps.
For example, the communication I / F unit 141 includes m client modules 142 # 1 to 142 # m that convert each of the m optical signals into divided frames.

  The signal processing unit 143 refers to the skew information included in each of the m divided frames supplied from the communication I / F unit 141, and each of the m divided frames supplied from the communication I / F unit 141. And a second signal processing unit that generates a frame obtained by combining For example, the signal processing unit 143 refers to m pieces of divided frames supplied from the communication I / F unit 141 with reference to skew information added to each divided frame, and the communication I / F 134 and the communication I / F unit 141 And calculate the amount of delay generated in the transmission between them, remove skew information from the divided frames, and align the data lanes. Then, after aligning the data lanes, the signal processing unit 143 combines the storage frames to generate the frame 20 illustrated in FIG. 5. Here, the frame 20 is in a data format for transmission at a transmission rate of n Gbps.

  The signal conversion unit 144 analyzes the frame 20 received from the signal processing unit 143, and extracts the data of the specific format used in the out-of-office communication stored in the payload of the frame 20. Signal conversion unit. Then, an electric signal indicating the extracted data is given to the I / F unit 145 for external use. The electric signal here is a signal for transmitting by k Gbps used in the out-of-station communication.

  The external I / F unit 145 is an interface for performing external communication. Here, the out-of-station I / F unit 145 converts the electrical signal of the transmission rate of k Gbps used in the out-of-office communication given from the signal conversion unit 144 into an optical signal. Then, the external I / F unit 145 transmits the converted optical signal to the transponder 150 at a transmission rate of k Gbps. In other words, the station external I / F unit 145 is a second transmission unit that transmits the data of the specific format extracted by the signal conversion unit 144 at the first transmission rate of k Gbps.

  As described above, since the signal processing unit 133 in the transponder 130 on the transmitting side deletes only the FEC data 13 in the OTU frame 10, the electrical signal of k Gbps is n Gbps while maintaining the OTU / ODU overhead 11. It is stored in the signal and divided. Then, since the overhead 11 and the payload 12 are restored by the signal processing unit 143 of the transponder 130 on the receiving side, transparent communication can be performed without processing the overhead 11.

  The transponders 130, 140 described above may be, for example, single circuits, complex circuits, programmed processors, parallel programmed processors, ASICs (Application Specific Integrated Circuits) or FPGAs, as shown in FIG. It can be configured by a processing circuit 180 having a (Field Programmable Gate Array) or the like.

  In the first embodiment, since each of the m divided frames has skew information, the signal processing unit 143 of the transponder 140 on the receiving side divides the m divided frames divided from one OTU frame. If received, calculation of delay amount and alignment of data lanes can be performed. Thus, transponder 130 and transponder 140 can be implemented with processing circuitry 180 using a smaller memory than prior art techniques using OTL.

  As described above, by performing frame processing in the inter-station transponder 130 and the transponder 140, only the transponder 120 at the termination point and the transponder 150 are replaced with the transponder for the client adjusted to the transmission rate of the signal transmitted from the customer transmission device 110. This enables the inter-station transponders 130 and 140 to transmit data even if the transmission rate of the client data transmitted from the customer transmission apparatus 110 changes while using the transponders in operation.

Second Embodiment
As shown in FIG. 1, the transmission system 200 according to the second embodiment includes a customer transmission device 110, a transponder 120, a transponder 230, a transponder 240, a transponder 150, and a customer transmission device 160. .
The customer transmission apparatus 110, the transponder 120, the transponder 150, and the customer transmission apparatus 160 in the transmission system 200 according to the second embodiment are configured in the same manner as the transmission system 100 in the first embodiment.

As shown in FIG. 2, the transponder 230 in the second embodiment includes an external I / F unit 131, a signal conversion unit 132, a signal processing unit 233, and a communication I / F unit 134. .
The external I / F unit 131, the signal conversion unit 132 and the communication I / F unit 134 of the transponder 230 in the second embodiment are configured in the same manner as the transponder 130 in the first embodiment.

As shown in FIG. 4, the signal processing unit 233 in the second embodiment includes an FEC data deletion unit 133 a, a data division unit 133 b, and a skew information addition unit 233 c.
The FEC data deleting unit 133a and the data dividing unit 133b of the signal processing unit 233 in the second embodiment are configured in the same manner as the signal processing unit 133 in the first embodiment.

  The skew information addition unit 233c carries out calculation of bit interleaved parity (BIP-8), which is an error detection code, from each storage frame generated by the data division unit 133b. Then, for example, as shown in FIG. 8, the skew information adding unit 233c stores the FEC data deleted by the FEC data deletion unit 133a in each storage frame generated by the data division unit 133b. A divided frame is generated by adding an error detection code (BIP-8) and skew information to the selected area.

As shown in FIG. 2, the transponder 240 according to the second embodiment includes a communication I / F unit 141, a signal processing unit 243, a signal conversion unit 144, and an I / F unit 145 directed to the outside of a station. .
The communication I / F unit 141, the signal conversion unit 144, and the external I / F unit 145 of the transponder 240 in the second embodiment are configured in the same manner as the transponder 140 in the first embodiment.

The signal processing unit 243 in the second embodiment performs error detection using the error detection code added to each of the m divided frames provided from the communication I / F unit 141.
Further, the signal processing unit 243 refers to the skew information attached to each of the m divided frames supplied from the communication I / F unit 141 with respect to the communication I / F 134 and the communication I / F unit 141. Calculate the amount of delay generated in the transmission between them, and remove the error detection code and the skew information from the divided frames to align the data lanes. Then, after aligning the data lanes, the signal processing unit 243 combines the storage frames to generate the frame 20 illustrated in FIG. 5. Here, the frame 20 has a data format for transmission at a transmission rate of n Gbps.

  As described above, in the second embodiment, the number of errors that occur during transmission between the communication I / F 134 and the communication I / F unit 141 can be calculated by adding the error detection code. For this reason, in the second embodiment, it is possible to investigate the transmission quality of communication.

Third Embodiment
As shown in FIG. 1, the transmission system 300 according to the third embodiment includes a customer transmission device 110, a transponder 120, a transponder 330, a transponder 340, a transponder 150, and a customer transmission device 160. .
The customer transmission device 110, the transponder 120, the transponder 150, and the customer transmission device 160 in the transmission system 300 according to the third embodiment are configured in the same manner as the transmission system 100 in the first embodiment.

As shown in FIG. 2, the transponder 330 in the third embodiment includes an external I / F unit 131, a signal conversion unit 132, a signal processing unit 333, and a communication I / F unit 134. .
The external I / F unit 131, the signal conversion unit 132, and the communication I / F unit 134 of the transponder 330 in the third embodiment are configured in the same manner as the transponder 130 in the first embodiment.

  The signal processing unit 333 divides the OTU frame generated by the signal conversion unit 132 into m storage frames predetermined in the column direction, and at the end of each of the m storage frames, the OTU frame Is a first signal processing unit that generates m divided frames by adding skew information indicating the arrangement position of each of the m storage frames in.

FIG. 9 is a block diagram schematically showing the configuration of the signal processing unit 333. As shown in FIG.
The signal processing unit 333 includes a data division unit 333 b and a skew information addition unit 333 c.
The signal processing unit 333 in the third embodiment does not delete the FEC data 183 from the OTU frame 10.

  The data division unit 333 b divides the OTU frame 10 provided from the signal conversion unit 132 into m storage frames determined in advance. The storage frame divided here has a data format for transmission at a transmission rate of n Gbps.

  As shown in FIG. 10, the skew information adding unit 333c generates divided frames by adding skew information to each storage frame generated by the data dividing unit 133b.

As shown in FIG. 2, the transponder 340 according to the third embodiment includes a communication I / F unit 141, a signal processing unit 343, a signal conversion unit 344, and an external I / F unit 145. .
The communication I / F unit 141 and the external I / F unit 145 of the transponder 340 in the third embodiment are configured in the same manner as the transponder 140 in the first embodiment.

The signal processing unit 343 in the second embodiment refers to the skew information included in each of the m divided frames supplied from the communication I / F unit 141, and combines each of the m divided frames. It is a 2nd signal processing part which generates an OTU frame by doing.
For example, the signal processing unit 343 refers to the m divided frames supplied from the communication I / F unit 141 with reference to the skew information added to each divided frame, and the communication I / F 134 and the communication I / F unit 141 And calculate the amount of delay generated in the transmission between them, remove skew information from the divided frames, and align the data lanes. Then, after aligning the data lanes, the signal processing unit 243 combines the storage frames to generate the OTU frame 10 shown in FIG. Here, the OTU frame 10 is in a data format for transmission at a transmission rate of n Gbps.

The signal conversion unit 344 performs error correction of the OTU frame 10 using the FEC data 13 included in the OTU frame 10 supplied from the signal processing unit 343.
Then, the signal conversion unit 344 analyzes the error-corrected OTU frame 10 and extracts data of a specific format used in the outside-office communication, which is stored in the payload 12. Then, an electric signal indicating the extracted data is given to the I / F unit 145 for external use.

As described above, in the third embodiment, since the FEC data 13 is included in the OTU frame 10 to be restored on the receiving side, error correction is performed when a data error occurs during intra-station transmission. Is possible.
Further, in the third embodiment, since the FEC data 13 is not deleted compared to the first embodiment, the transmission rate of the signal output from the client module is increased, but the circuit for deleting the FEC data is not necessary. The circuit scale can be reduced.

Fourth Embodiment
As shown in FIG. 1, a transmission system 400 according to the fourth embodiment includes a customer transmission device 110, a transponder 120, a transponder 430, a transponder 440, a transponder 150, and a customer transmission device 160. .
The customer transmission device 110, the transponder 120, the transponder 150, and the customer transmission device 160 in the transmission system 400 according to the fourth embodiment are configured in the same manner as the transmission system 100 in the first embodiment.

FIG. 11 is a block diagram schematically showing configurations of transponder 430 and transponder 440 in the fourth embodiment.
Here, the transponder 430 and the transponder 440 in the fourth embodiment are connected by m + 1 optical fibers.
The transponder 430 includes an external I / F unit 131, a signal conversion unit 132, a signal processing unit 433 and a communication I / F unit 434.
The external I / F unit 131 and the signal conversion unit 132 of the transponder 430 in the fourth embodiment are configured in the same manner as the transponder 130 in the first embodiment.

  The signal processing unit 433 in the fourth embodiment generates m divided frames by dividing the OTU frame supplied from the signal conversion unit 132 into m predetermined frames in the column direction, and It is a first signal processing unit that generates one skew information frame storing skew information indicating the arrangement position of each of the m divided frames in the OTU frame.

As shown in FIG. 9, the signal processing unit 433 in the fourth embodiment includes a data division unit 333 b and a skew information addition unit 433 c.
The data division unit 333 b of the signal processing unit 433 in the fourth embodiment is configured the same as the signal processing unit 333 in the third embodiment.

  The skew information addition unit 433c generates a skew information frame including skew information indicating the arrangement position of each storage frame generated by the data division unit 333b. Then, as shown in FIG. 12, the skew information addition unit 433c sets the m storage frames generated by the data division unit 333b as m division frames, and adds the skew information frame FL # to the division frames. The added m + 1 frames are provided to the communication I / F unit 434. Here, it is assumed that skew information of a predetermined divided frame is stored in the skew information frame in a predetermined order.

The communication I / F unit 434 shown in FIG. 11 changes the m divided frames and one skew information frame subjected to frame processing into m + 1 optical signals, and m + 1 optical signals are m + 1 The optical fibers 101 # 1 to 101 # m + 1 of the book are transmitted to the transponder 440.
For example, the communication I / F unit 434 is composed of m + 1 client modules 435 # 1-435 # m + 1 that convert each of the m divided frames and one skew information frame into an optical signal.

As shown in FIG. 11, the transponder 440 in the fourth embodiment includes a communication I / F unit 441, a signal processing unit 443, a signal conversion unit 344, and an external I / F unit 145. .
The signal conversion unit 344 of the transponder 440 in the fourth embodiment is configured in the same manner as the transponder 340 in the third embodiment.
The external I / F unit 145 of the transponder 440 in the fourth embodiment is configured in the same manner as the transponder 140 in the first embodiment.

The communication I / F unit 441 according to the fourth embodiment receives m + 1 optical signals from m + 1 optical fibers 101 # 1 to 101 # m + 1 and converts m optical signals into m divided frames. , Convert the remaining one optical signal into a skew information frame. This divided frame is in a data format for transmission at an n Gbps transmission rate.
For example, the communication I / F unit 441 converts m client modules 442 # 1 to 442 # m that convert each of the m optical signals into divided frames, and converts the remaining one optical signal into a skew information frame. And a client module 442 # m + 1.

The signal processing unit 443 in the fourth embodiment refers to the skew information stored in the skew information frame supplied from the communication I / F unit 441, and transmits the m divided frames supplied from the communication I / F unit 441. It is a second signal processing unit that generates an OTU frame by combining each other.
For example, the signal processing unit 443 refers to the m divided frames supplied from the communication I / F unit 441 with reference to the skew information included in the skew information frame supplied from the communication I / F unit 441, and performs communication I Calculate the delay amount generated in the transmission between / F 434 and communication I / F section 441 and align the data lanes. Then, after aligning the data lanes, the signal processing unit 243 combines the divided frames to generate the OTU frame 10 shown in FIG. Here, the OTU frame 10 is in a data format for transmission at a transmission rate of n Gbps.
In addition, since the skew information becomes unnecessary after the alignment of the data lanes, the signal processing unit 443 discards the information.

  As described above, in the fourth embodiment, as in the third embodiment described above, since the divided frames include the FEC data 13, error correction can be performed by the transponder 440 on the receiving side. On the other hand, in the fourth embodiment, the transmission rate of the frame output from the communication I / F unit 434 can be made lower than in the third embodiment.

  100, 200, 300, 400 transmission system, 101 optical fiber, 110 customer transmission device, 120 transponder, 130, 230, 330, 430 transponder, 131 external I / F unit, 132 signal conversion unit, 133, 233, 333, 433 signal processing unit, 133a FEC data deletion unit, 133b data division unit, 133c, 233c, 433c skew information addition unit, 134, 434 communication I / F unit, 135, 435 client module, 140, 240, 340, 440 transponder, 141, 441 communication I / F unit, 142, 442 client module, 143, 243, 343, 443 signal processing unit, 144, 344 signal conversion unit, 145 external I / F unit, 150 tiger Suponda, 160 customer transmission apparatus 180 processing circuits.

Claims (3)

A first transponder receiving a specific type of data transmitted at a first transmission rate, and a second transponder connected to the first transponder by m (m is an integer of 2 or more) optical fibers A transmission system including a transponder of
The first transponder is
A first receiving unit for receiving data of a specific format transmitted at the first transmission rate;
A first signal conversion unit for generating an OTU frame storing data of a specific format received by the first reception unit;
The FEC data is deleted from the OTU frame generated by the first signal conversion unit, divided into m storage frames determined in advance in the column direction, and the FEC data is generated in each of the m storage frames A first signal processing unit that generates m divided frames by adding skew information indicating the arrangement position of each of the m storage frames in the OTU frame to the area from which b.
A first transmission unit for transmitting each of the m divided frames generated by the first signal processing unit from each of the m optical fibers to the second transponder at a second transmission rate; Equipped with
The second transponder is
A second receiving unit that receives each of the m divided frames transmitted from the first transmission unit from each of the m optical fibers;
A frame obtained by combining each of the m divided frames received by the second receiving unit with reference to the skew information included in each of the m divided frames received by the second receiving unit A second signal processing unit that generates
A second signal conversion unit that extracts data of the specific format from the frame generated by the second signal processing unit;
A second transmission unit that transmits data of a specific format extracted by the second signal conversion unit at the first transmission rate. The first signal processing unit adds an error detection code calculated from each of the m storage frames to an area from which the FEC data is deleted, in addition to the skew information.
The second signal processing unit performs error detection using an error detection code included in each of the m divided frames received by the second receiving unit. Transmission system described in. A first transponder receiving a specific type of data transmitted at a first transmission rate, and a second transponder connected to the first transponder by m (m is an integer of 2 or more) optical fibers A transmission system including a transponder of
The first transponder is
A first receiving unit for receiving data of a specific format transmitted at the first transmission rate;
A first signal conversion unit for generating an OTU frame storing data of a specific format received by the first reception unit;
The OTU frame generated by the first signal conversion unit is divided in the column direction into m storage frames determined in advance, and the OTU frame is newly added at the end of each of the m storage frames. A first signal processing unit that generates m divided frames by adding skew information indicating the arrangement position of each of the m storage frames in step b.
A first transmission unit for transmitting each of the m divided frames generated by the first signal processing unit from each of the m optical fibers to the second transponder at a second transmission rate; Equipped with
The second transponder is
A second receiving unit that receives each of the m divided frames transmitted from the first transmission unit from each of the m optical fibers;
Combining each of the m divided frames received by the second receiving unit with reference to skew information included in each of the m divided frames received by the second receiving unit; A second signal processing unit that generates an OTU frame by
A second signal conversion unit that performs error correction of the OTU frame generated by the second signal processing unit, and extracts data of the specific format from the OTU frame generated by the second signal processing unit; ,
A second transmission unit that transmits data of a specific format extracted by the second signal conversion unit at the first transmission rate.

Images