JPH09289657A - Optical signal transmitter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To minimize a transmission loss caused when an optical signal transmitter is inserted to an optical transmission line and to minimize missing of data due to switching of a transmission line. SOLUTION: Data sent through plural optical transmission lines are converted into electric signals and converted into parallel data by extracting a synchronizing signal clock. The parallel data are converted into optical signals and amplified and then the resulting signal is sent to a selected output transmission line by switching the transmission lines synchronously with the synchronizing clock. Thus, the transmission loss caused when the optical signal transmitter is inserted to the optical transmission line is minimized and missing of data due to the selection of the transmission lines is minimized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical signal transmission device used in a system having an optical transmission line.

[0002]

2. Description of the Related Art FIG. 9 shows a conventional optical signal transmission device. In FIG. 9, reference numeral 13 is a 2 × 2 switch unit for switching the optical transmission line of 2 to 2. FIG. 10 shows the structure of the 2 × 2 switch unit 13. In FIGS. 10 and 11, 14 is an input optical cable to which the input terminals of the 2 × 2 switch unit 13 are connected, 15 is an input terminal to which the input optical cable 14 is connected, 16 is an output terminal in contact with the input terminal 15,
17 is an output optical cable for outputting the output terminal 16 to the outside,
Reference numeral 18 denotes a switch driving unit that changes the connection between the input terminal 15 and the output terminal 16. FIG. 11 shows the structure of the 2 × 2 switch section 13 as in FIG. 10, but shows the state when a voltage is applied to the switch drive section 18 to change the connection destination.

[0003]

The conventional optical signal transmission device has the structure as described above, and the 2 × 2 optical switch section 13 has a switch driving section 18 as shown in FIGS.
A connection destination is selected by applying a voltage to. Therefore,
The joint surface between the input terminal 15 and the output terminal 16 is required to have sufficient accuracy to match the optical fiber surfaces, and transmission loss occurs at this joint surface. In addition, since the connection is mechanically changed by applying a voltage to the switch driving unit 18, the accuracy of the joint surface is deviated due to aging, so this reliability becomes low, and the speed required for switching is the same as that of the optical transmission line. It is very low compared to the data transfer rate.

Further, as shown in FIG. 9, the optical signal transmission device corresponding to the many-to-many optical transmission line is realized by combining the 2 × 2 optical switch unit 13. However, the 2 × 2 optical switch unit is The transmission loss and the transfer rate due to the connection between the 13 are several times that of the 2 × 2 optical switch unit 13 alone. In order to reduce the transmission loss due to this connection, a transmission line with a low transmission loss is used, and the connection with the 2 × 2 optical switch unit 13 is made by splicing or the like instead of using a connector. For the × 2 optical switch unit 13, it is necessary to make efforts such as selecting a component with the lowest transmission loss. As a result,
The conventional optical signal transmission device is very difficult to manufacture as a product, and the cost is high.

Therefore, the conventional optical signal transmission device is required to have a high degree of accuracy, and although the transmission device can be reduced by manufacturing efforts, it cannot be greatly reduced. Also,
Since the mechanical switching is performed, its reliability and maintainability are much lower than those of electrical parts, and the switching speed is much lower than the optical transmission speed. The data input to the transmission device will be lost. The conventional optical signal transmission device has the above problems.

The present invention has been made in order to solve the above problems, and it is possible to minimize the insertion loss of an optical transmission device and to ensure the reliability and maintainability equivalent to those of electric parts. The purpose is to eliminate data loss due to switching.

[0007]

Means for Solving the Problems In the first invention,
Converts optical data into parallel electrical signals once, and switches the connection destination in synchronization with the clock of this optical data.
The present invention provides an optical signal transmission device that minimizes transmission loss by converting serial optical data again and amplifying the signal level.

In the second aspect of the invention, the optical data is once converted into parallel electric signals, the connection destination is switched, the serial optical data is converted and output again, and the signal level is amplified. Data loss due to switching is eliminated by minimizing the transmission loss and buffering the data after converting it to an electrical signal,
It enables switching between optical transmission lines with different transmission rates.

According to the third aspect of the invention, the optical data is once converted into parallel electric signals, the connection destination is switched, the serial optical data is converted and output again, thereby amplifying the signal level to thereby reduce the transmission loss. To the minimum,
By converting the data to an electrical signal and then buffering the data, the loss of data due to switching can be eliminated to enable switching between optical transmission lines with different transmission rates, and further buffering after switching enables transmission of the optical transmission line. An optical signal transmission device that improves efficiency is provided.

In the fourth aspect of the invention, the optical data is once converted into parallel electrical signals, the connection destination is switched, the serial optical data is converted and output again, and the signal level is amplified. By minimizing the transmission loss and buffering the data after converting it to an electrical signal, the loss of data due to switching can be eliminated and switching between optical transmission lines with different transmission rates can be performed, and switching can be performed for each optical input data. An optical signal transmission device for dynamically switching the optical transmission line by performing the switching request data in the optical transmission line, and further buffering after the switching, thereby improving the transmission efficiency of the optical transmission line.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1 FIG. 1 is a diagram showing Embodiment 1 of the present invention. 1 is O / that converts an optical signal input from the optical transmission line into an electrical signal
E (Optical / Electric) converter 2, 2 is a clock synchronizer for extracting a clock from the electric signal converted by the O / E converter 1, and 3 is a serial electric signal converted by the O / E converter 1. An S / P (Serial / Parallel) register unit for converting into parallel and temporarily storing, 4 is a connection selecting unit for determining a connection destination and connecting.
Reference numeral 5 is a P / S register unit for converting the parallel electric signal whose connection destination is determined by the connection selection unit 4 into serial, and 6 is a P / S
An output clock synchronization unit that synchronizes the data serialized by the register unit 5 with a clock, 7 is an E / O conversion unit that converts a serial electric signal into an optical signal and amplifies the signal level, and 8 determines a connection destination Then, it is a selection switch unit that notifies each connection destination to the connection selection unit 4. Further, FIG. 2 is a diagram showing an operation timing according to the first embodiment of the present invention.

The operating principle of the optical signal transmission device configured as described above will be described with reference to FIGS. The optical signal of each optical transmission line is input to the O / E converter 1 and converted into an electric signal. The input clock synchronization unit 2 extracts the synchronization clock from the data converted into the electric signal by the O / E conversion unit 1. The data is converted from serial data to parallel data by the S / P register unit 3. Also, the connection destination is determined by the selection switch unit 8, and accordingly, the connection selection unit 4 outputs the output data of each S / P register output unit 3 to each P
Input to the / S register unit 5. Here, the synchronization clock extracted by each input clock synchronization unit 2 and the output data of the S / P register output unit 3 are asynchronous with each other, but the switching timing is the synchronization clock extracted by the input clock synchronization unit 2. Based on one. The data input to each P / S register unit 5 is converted into serial data again, and is synchronized with the clock in the output synchronization clock unit 6 to E /
It is converted into an optical signal by the O conversion unit 7, amplified, and output to each optical transmission line. The operation timing of the first embodiment of the present invention shown in FIG. 2 is based on the synchronous clock of the first input. Further, in FIG. 2, the first input, the second input, the third input, and the fourth input are respectively output to the first output, the second output, the third output, and the fourth output, Timing when the first input, the second input, the third input, and the fourth input are output to the fourth output, the third output, the second output, and the first output, respectively, by switching the connection. Is shown. In this case, the second input to the fourth input are switched at the timing of the first input even though they are asynchronous with the first input, so the data at this moment disappears, but from the next data Is transmitted normally. Therefore, unlike the conventional optical signal transmission device, data is not lost for several ms. Also, the only precision parts required for optical devices are the input and output connectors to the transmission line,
It is possible to minimize the transmission loss that occurs when the first embodiment of the present invention is inserted into the optical transmission line.

Second Embodiment FIG. 3 is a diagram showing a second embodiment of the present invention. 1 to 8 are the same as those in the first embodiment of the present invention.
Reference numeral 9 denotes an input buffer unit that buffers each data that has become parallel data in the S / P (Serial / Parallel) register unit 3, and 10 is a selection timing generation unit that synchronizes the timing of sending data to a plurality of transmission lines. is there. Further, FIG. 4 is a diagram showing an operation timing according to the second embodiment of the present invention.

The operating principle of the optical signal transmission device configured as described above will be described with reference to FIGS. 3 and 4. The optical signal of each optical transmission line is O / E (Optical / Electric)
It is input to the conversion unit 1 and converted into an electric signal. The input clock synchronization unit 2 extracts the synchronization clock from the data converted into the electric signal by the O / E conversion unit 1. Data is S
The / P register unit 3 converts the serial data into parallel data and stores it in the input buffer unit 9 in order to synchronize the timing with other input data. The selection timing generation unit 10 generates this synchronization timing and outputs the data stored in each input buffer unit 9 to the FIFO (F
Each data is sequentially sent to the connection selection unit 4 in synchronization with the “ast in Fast out” method. The connection destination is determined by the selection switch section 8, and the connection selection section 4 outputs each input data to each P / S register section 5 accordingly. The data input to each P / S register unit 5 is again converted into serial data, synchronized with the clock by the output synchronization clock unit 6 and converted into an optical signal by the E / O conversion unit 7,
It is amplified and output to each optical transmission line. The operation timing of the second embodiment of the present invention shown in FIG.
Input, the third input, and the fourth input are output to the first output, the second output, the third output, and the fourth output, respectively.
Timing when the first input, the second input, the third input, and the fourth input are output to the fourth output, the third output, the second output, and the first output, respectively, by switching the connection. Is shown. At this time, the data from the first input to the fourth input are asynchronous with each other, but due to the buffering in the input buffer unit 9 and the timing synchronization in the selection timing generation unit 10, data loss at the moment of switching is caused. It is possible to switch between optical transmission lines having different transmission rates even if they are completely eliminated. Further, the only parts required for accuracy in the optical device are the input and output connectors to the transmission line, and the transmission loss that occurs when the second embodiment of the present invention is inserted into the optical transmission line is minimized. be able to.

Third Embodiment FIG. 5 is a diagram showing a third embodiment of the present invention. 1 to 10 are the same as those in the second embodiment of the present invention. Reference numeral 11 denotes an output FIFO (Fast in Fast ou) for improving the efficiency of data transmitted to the optical transmission line.
t) part. FIG. 6 is a diagram showing the operation timing of the third embodiment of the present invention.

The operation principle of the optical signal transmission device configured as described above will be described with reference to FIGS. The light of each optical transmission line is input to an O / E (Optical / Electric) conversion unit 1 and converted into an electric signal. The input clock synchronization unit 2 extracts the synchronization clock from the data converted into the electric signal by the O / E conversion unit 1. Data is S / P
In the (Serial / Parallel) register unit 3, serial data is converted into parallel data and stored in the input buffer unit 9 in order to synchronize the timing with other input data. The selection timing generation unit 10 generates this synchronization timing and converts the data stored in each input buffer unit 9 into a FIFO (Fastin Fast).
out) system, each data is sequentially sent to the connection selection unit 4 in synchronization. Further, the connection destination is determined by the selection switch unit 8, and the connection selection unit 4 outputs each input data to each output FIFO unit 10 accordingly. Output FIFO unit 1
0 is intended to make transmitted data dense, as shown in the operation timing of the third embodiment of the present invention in FIG.

Data of the input optical transmission line may or may not be continuous. Therefore, the transmission efficiency of the transmission path is improved by shortening the time when data is not sent. This is effective when the data is concentrated on one output end by switching the connection, for example. Each P / S register unit 5 converts the data input from the output FIFO unit 10 into serial data again, and is synchronized with the clock by the output synchronization clock unit 6 and converted into an optical signal by the E / O conversion unit 7 and amplified. It is output to each optical transmission line. FIG.
In the operation timing of the third embodiment of the present invention shown in FIG. 1, the first input, the second input, the third input, and the fourth input are the first output, the second output, and the third output, respectively. The fourth input is output to the fourth output, and the first input, the second input, the third input, and the fourth input are changed to the fourth output, the third output, the second output, and the first output by switching the connection. It shows the timing when output to the output. At this time, the data from the first input to the fourth input are asynchronous with each other, but due to the buffering in the input buffer unit 9 and the timing synchronization in the selection timing generation unit 10, data loss at the moment of switching is caused. It is completely eliminated, enabling switching between optical transmission lines with different transmission rates. Further, the improvement of the transmission efficiency in the output FIFO unit 11 corresponds to the increase of the transmission rate due to the connection switching.

Further, the only precision parts required for the optical device are the input and output connectors to the transmission line, and the transmission loss generated when the third embodiment of the present invention is inserted into the optical transmission line is the minimum. You can keep it to the limit.

Fourth Embodiment FIG. 7 is a diagram showing a fourth embodiment of the present invention. 1 to 7 and 9 and 11 are the same as those in the third embodiment of the present invention. A selection request arbitration unit 12 detects a connection request in the data and determines a connection destination. Further, FIG. 8 is a diagram showing an operation timing according to the fourth embodiment of the present invention.

The operating principle of the optical signal transmission device configured as described above will be described with reference to FIGS. 7 and 8. The light of each optical transmission line is input to an O / E (Optical / Electric) conversion unit 1 and converted into an electric signal. The input clock synchronization unit 2 extracts the synchronization clock from the data converted into the electric signal by the O / E conversion unit 1. Data is S / P
In the (Serial / Parallel) register unit 3, serial data is converted into parallel data and stored in the input buffer unit 9 in order to synchronize the timing with other input data. The selection timing generation unit 10 generates this synchronization timing and converts the data stored in each input buffer unit 9 into a FIFO (Fastin Fast).
out) method, the respective data are synchronously and sequentially transmitted to the selection request arbitration unit 12. The selection request arbitration unit 12 extracts a selection request signal from the data and arbitrates and determines the connection destination. The connection selection unit 4 performs data connection according to the connection information determined by the selection request arbitration unit, and connects to each output FIFO unit 10. The output FIFO unit 10 aims to make transmitted data dense, as shown in the operation timing of the fourth embodiment of the present invention in FIG. The input data of the optical transmission line may be continuous or not continuous. Therefore, the transmission efficiency of the transmission path is improved by shortening the time when data is not sent. This is effective when the data is concentrated on one output end by switching the connection, for example. Each P / S register unit 5 converts the data input from the output FIFO unit 10 into serial data again, and is synchronized with the clock by the output synchronization clock unit 6 and converted into an optical signal by the E / O conversion unit 7 and amplified. It is output to each optical transmission line.

The operation timing of the fourth embodiment of the present invention shown in FIG. 8 is as follows: first input, second input, third input,
The fourth input is output to the first output, the second output, the third output, and the fourth output, respectively, and the first input, the second input, the third input, depending on the connection request in the data, It shows the timing when all the fourth inputs are output to the first output. At this time, although the data from the first input to the fourth input are asynchronous with each other, the input buffer unit 9
By the buffering in step 1 and the timing synchronization in the selection timing generator 10, there is no loss of data at the moment of switching, and it is possible to switch between optical transmission lines with different transmission rates. Further, the improvement of the transmission efficiency in the output FIFO unit 11 corresponds to the increase of the transmission rate due to the connection switching.

Further, the only precision parts required for the optical device are the input and output connectors to the transmission line, and the transmission loss generated when the fourth embodiment of the present invention is inserted into the optical transmission line is the minimum. You can keep it to the limit.

[0023]

As described above, according to the first aspect of the present invention, the only parts having the precision required for the optical device are the input and output connectors to the transmission line, and the optical fiber according to the first embodiment of the present invention can be used. The transmission loss that occurs when it is inserted into the transmission path can be suppressed to the minimum, and the switching is electrically performed, so that the reliability can be improved.

According to the second aspect of the present invention, data loss at the moment of switching is completely eliminated, and further switching between optical transmission lines having different transmission rates is possible. In addition, the only precision parts required for optical devices are the input and output connectors to the transmission line, and the transmission loss that occurs when the optical device is inserted into the optical transmission line can be minimized, and switching can be done electrically. The reliability can be improved because it is performed.

According to the third aspect of the present invention, data loss at the moment of switching is completely eliminated, switching between optical transmission lines having different transmission rates is possible, and the increase in transmission rate due to connection switching is dealt with. In addition, the only precision parts required for optical devices are the input and output connectors to the transmission line, and the transmission loss that occurs when the optical device is inserted into the optical transmission line can be minimized, and switching can be done electrically. The reliability can be improved because it is performed.

According to the fourth aspect of the present invention, data loss at the moment of switching is completely eliminated, and further switching between optical transmission lines having different transmission rates is possible, and the transmission rate can be increased by switching the connection. Then, the connection is switched according to the connection request in the data, so that the connection of the optical transmission line can be dynamically changed. In addition, the only precision parts required for optical devices are the input and output connectors to the transmission line, and the transmission loss that occurs when the optical device is inserted into the optical transmission line can be minimized, and switching can be done electrically. The reliability can be improved because it is performed.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an optical signal transmission device according to a first embodiment of the present invention.

FIG. 2 is a diagram showing an operation timing according to the first embodiment of the present invention.

FIG. 3 is a block diagram showing a configuration of an optical signal transmission device according to a second embodiment of the present invention.

FIG. 4 is a diagram showing operation timing according to the second embodiment of the present invention.

FIG. 5 is a block diagram showing a configuration of an optical signal transmission device according to a third embodiment of the present invention.

FIG. 6 is a diagram showing an operation timing according to the third embodiment of the present invention.

FIG. 7 is a block diagram showing a configuration of an optical signal transmission device according to a fourth embodiment of the present invention.

FIG. 8 is a diagram showing operation timing according to the fourth embodiment of the present invention.

FIG. 9 is a block diagram showing a configuration of a conventional optical signal transmission device.

FIG. 10 is a diagram showing a structure of a 2 × 2 switch unit used in a conventional optical signal transmission device.

FIG. 11 is a diagram showing an operation of a 2 × 2 switch unit used in a conventional optical signal transmission device.

[Explanation of symbols]

 1 O / E conversion unit 2 Input clock synchronization unit 3 S / P register unit 4 Connection selection unit 5 P / S register unit 6 Output clock synchronization unit 7 E / O conversion unit 8 Selection switch unit 9 Input buffer unit 10 Selection timing generation Section 11 output FIFO section 12 selection request arbitration section 13 2 × 2 switch section 14 input optical cable 15 input terminal 16 output terminal 17 output optical cable 18 switch drive section

Claims (4)

[Claims] 1. An O / E (Optical / Elect) for converting an optical signal transmitted through a plurality of optical transmission lines into an electrical signal.
ric) a conversion unit, an input clock synchronization unit for extracting a clock from the electric signal converted by the O / E conversion unit, and a conversion of the electric signal converted by the O / E conversion unit into parallel data. S / P (Serial
/ Parallel) register section, an input selection section for selecting a connection transmission line of a plurality of electric signals converted into the parallel data, and a selection switch for performing this input selection,
A P / S register unit for converting the selected electric signal into serial data, an output clock synchronization unit for synchronizing the serial data with a clock, and an electric signal converted into the serial data into an optical signal. And an E / O conversion unit for sending out to a plurality of optical transmission lines. 2. An O / E (Optical / Elect) for converting an optical signal transmitted through a plurality of optical transmission lines into an electric signal.
ric) a conversion unit, an input clock synchronization unit for extracting a clock from the electric signal converted by the O / E conversion unit, and a conversion of the electric signal converted by the O / E conversion unit into parallel data. S / P (Serial
/ Parallel) register section, an input buffer section for buffering each input data from the S / P register section, a selection timing generating section for generating output timing of the input buffer section, and an output from the input buffer , An input selection section for selecting the transmission line, a selection switch for performing this input selection, a P / S register section for converting an electric signal from the selected input buffer into serial data, and a clock for this serial data. And an E / O conversion unit for converting the electric signal converted into the serial data into an optical signal and transmitting the optical signal to a plurality of optical transmission lines. Transmission equipment. 3. The optical signal transmission device according to claim 2, further comprising an output FIFO unit for adjusting the output timing of the selected data between the input selection unit and the P / S register unit. 4. An O / E (Optical / Elect) for converting an optical signal transmitted through a plurality of optical transmission lines into an electrical signal.
ric) converting unit, an input clock synchronizing unit for extracting a clock from the electric signal converted by the O / E converting unit, and converting the electric signal converted by the O / E converting unit into parallel data. S / P (Serial
/ Parallel) register section, an input buffer section that buffers each input data from the S / P register section, and a connection request signal is extracted from the data input from the input buffer section to determine a connection destination. A selection request arbitration unit, an input selection unit that selects a connection transmission path of a plurality of electric signals, a selection switch that performs this input selection, and a P / that converts the selected electric signals into serial data.
An S register unit, an output clock synchronization unit that synchronizes the serial data with a clock, and an E / O conversion unit that converts the electrical signal converted into the serial data into an optical signal and sends the optical signal to a plurality of optical transmission lines. An optical signal transmission device comprising: