JP2003018626A - Common path switching device for electrical path and optical path - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a common path switching device for an electrical path and an optical path which achieves miniaturization of the device, cost reduction and low power consumption, by reducing the number of redundant electric- optical conversion and also remarkably reducing the number of electronic circuits. SOLUTION: Switching of electrical transmission paths by electrical switches 4 of receiver side terminating devices 10-1 through 10-n, and switching by electrical switches 6 of transmitter side terminating devices 30-1 through 30-n, are performed in corporation with switching of transmission paths in an optical region by an optical switch 2, thereby switching the transmission paths.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a path switching device such as a cross-connect device or an ADM (Add Drop Multiplexer) device for switching a large-capacity optical / electrical signal in an optical communication network. The present invention relates to an electric / optical shared path switching device in which an electric switch for path switching and an optical switch for path switching with an optical signal coexist.

[0002]

2. Description of the Related Art A cross-connect device has a function of switching a plurality of transmission lines, and an ADM device is provided between a high-order layer transmission line of a trunk line and a branch low-order layer transmission line. , Signal extraction (drop) and signal insertion (add).

Conventionally, in an optical communication network, line control has been performed by converting an optical signal into an electric signal and controlling switching by an electric switch. FIG. 6 shows Japanese Patent Laid-Open No. 5-114489.
2 shows a conceptual configuration of a conventional cross-connect device disclosed in Japanese Patent Publication No.

This conventional cross-connect device includes a plurality of terminating devices 110-1 to 110-n, a routing device 100 for switching lines, and a network control device 13.
It has 0 and. Each terminating device 110-1 to 110-n
Is a plurality of optical / electrical conversion units 101 to 101-m for converting an optical signal as an external interface received via a plurality of optical transmission lines into an electric signal, and a failure of external transmission data received from each transmission line. Multiple monitoring units 102-1 for monitoring
102-m, and a plurality of electric / optical conversion units 103-1 to 103-m for converting electric signals into optical signals for transmitting large-capacity signals between devices.

The routing device 100 includes a plurality of optical / electrical converters 104-1 to 104-j for converting optical signals from the plurality of terminating devices 110-1 to 110-n into electric signals.
And an electrical switch unit 111 that electrically switches transmission paths of electrical signals from the optical / electrical converters 104-1 to 104-j, and a plurality of electrical signals output from the electrical switch unit 111 into optical signals. A plurality of electric / optical conversion units 10 for conversion
5-1 to 105-j, and optical signals output from the plurality of output side electric / optical conversion units 105-1 to 105-j are sent to the plurality of optical transmission lines. The network control device 130 sets a transmission path based on the information from each of the monitoring units 102-1 to 102-m of the terminal devices 110-1 to 110-n, and an electric switch according to the set transmission path. The switching control of the unit 111 is executed.

A broadband optical signal is capable of high-speed data transmission exceeding gigabit, and in order to electrically switch it, the electric switch section 111 has an electric switch other than an electric switch for switching a transmission path. , A demultiplexing processing unit 105 that switches a high-speed signal to a low-speed signal, a parallel distributed processing unit 106 that parallel-distributes a low-speed signal to maintain the same processing speed as a high-speed signal, and a low-speed signal to a high-speed signal again. It is necessary to include the multiplexing processing unit 107 for converting. Therefore, in the conventional device, the electric switch unit 111 of the routing device 100 needs a large-scale and huge electronic circuit, which causes a problem that the device also becomes large.

Particularly, in the cross-connect device having the add / drop function, the transmission rate of the signal of the branch low-order layer (low-order group) is matched with the transmission rate of the signal of the trunk high-order layer (high-order group). In addition, it was necessary to perform demultiplexing processing, which required a huge amount of electronic circuits.

Further, normally, the terminators 110-1 to 110 are used.
-N, the routing device 100, etc. are stored separately in a plurality of racks, and in performing wiring connection of the terminating devices 110-1 to 110-n and the routing device 100 which are separately stored in such a plurality of racks. In the electrical connection, since high frequency signals are easily affected by electromagnetic noise, as a preventive measure, the plurality of racks are connected by an optical transmission line. Therefore, in the related art, the terminating device 110-
1 to 110-n provided in the electro-optical conversion unit 103-1
˜103-m and extra electricity ← → optical converters such as optical / electrical converters 104-1 to 104-j provided in the routing device 100, and redundant electrical-optical-electrical ( E / O / E) conversion is required.

[0009]

Since the conventional cross-connect device has the above-mentioned configuration, it requires a huge amount of electronic circuits and redundant E / O / E conversion, which increases the cost of the device.
It caused large size and large power consumption. Furthermore, wavelength multiplexing technology that multiplexes signals in the optical domain has also been put into practical use, and looking at the ever-increasing amount of signals,
This tendency is only increasing.

The present invention has been made in view of the above,
By switching the transmission path that shares the electric switch and the optical switch, redundant electric / optical conversion can be reduced and electronic circuits can be drastically reduced to achieve miniaturization, low cost, and low power consumption. An object is to provide an optical shared path switching device.

[0011]

In order to achieve the above object, an electric / optical shared path switching device according to the present invention comprises a plurality of first electric signals for converting optical signals from a plurality of optical transmission lines into electric signals.
Optical / electrical conversion unit, a first electrical switch for electrically switching the transmission paths of the plurality of electrical signals that have been optically / electrically converted in the terminating device, and the first electrical switch for switching output. A plurality of receiving side terminating devices each having a plurality of first electric / optical converting portions for converting a plurality of electric signals into optical signals and outputting the optical signals to the optical switch, and a plurality of optical signals input from the optical switch A plurality of second optical / electrical conversion units for converting the electric signals into electric signals, a second electric switch for electrically switching the transmission paths of the plurality of optical / electrically converted electric signals, and the second electric A plurality of transmission-side terminating devices having a second electric / optical conversion unit for converting a plurality of electric signals switched and output by the switch into optical signals and transmitting the optical signals to a plurality of optical transmission lines are provided, and the plurality of reception devices are provided. A plurality of first electric / optical devices respectively included in the side termination devices An optical switch for switching a transmission path between an optical conversion unit and a plurality of second optical / electrical conversion units included in each of the plurality of transmission-side termination devices in an optical region, and setting the transmission path to make this setting. According to the transmission path, an electrical switch of the plurality of receiving-side terminating devices, an electrical switch of the plurality of transmitting-side terminating devices, and a network control device that performs switching control of the optical switch are provided.

According to the present invention, the switching of the electrical transmission path by the electric switch of the receiving side terminating device and the electric switch of the transmitting side terminating device and the switching of the transmission path in the optical region by the optical switch are made to cooperate. Switch the transmission path.

In the electric / optical shared path switching device according to the next invention, in the above invention, the first optical / electrical conversion unit monitors a failure of external transmission data, and the monitoring result is used for the network control. Has a monitoring unit that notifies the device,
The network control device sets the transmission path based on the monitoring result from the monitoring unit, and the electric switches of the plurality of receiving side terminating devices and the electric switches of the plurality of transmitting side terminating devices according to the setting contents. And controlling the switching of the optical switch.

According to the present invention, a failure in externally transmitted data is monitored, and switching control of the electric switch of the receiving side terminating device, the electric switch of the transmitting side terminating device and the optical switch is controlled based on the monitoring result. ing.

In the electric / optical shared path switching device according to the next invention, in the above invention, an optical signal monitoring unit for monitoring the power of the optical signal is provided in the input port or output port of the optical switch or in the optical switch. It is characterized by

According to this invention, the connection state in the optical switch is monitored by monitoring the power of the optical signal input to and output from the optical switch.

In the electric / optical shared path switching device according to the next invention, in the above invention, a supervisory control information inserting section for periodically inserting supervisory control information into an optical signal inputted to the optical switch, and the optical signal are provided. And a monitoring control information monitoring unit that monitors the monitoring control information included in the optical signal output from the switch.

According to the present invention, the monitoring control information is periodically inserted into the optical signal input to the optical switch, and the monitoring control information contained in the optical signal output from the optical switch is monitored, whereby The connection status in the switch is monitored.

In the electric / optical shared path switching device according to the next invention, in the above invention, an error correction code adding section for adding an error correction code to an optical signal input to the optical switch, and an output from the optical switch. And an error correction code decoding unit for decoding the error correction code included in the optical signal.

According to the present invention, the error correction code is added to the optical signal input to the optical switch, and the error correction code included in the optical signal output from the optical switch is decoded, so that I am trying to monitor the connection status.

In the electric / optical shared path switching device according to the next invention, in the above invention, the optical switch has a spare optical switch, and the network control device protects from a working optical switch when a failure occurs. It is characterized by switching to the optical switch of.

According to the present invention, the optical switch is provided with a protection function by switching from the working optical switch to the spare optical switch when a failure occurs.

In the electric / optical shared path switching device according to the next invention, in the above invention, the optical switch is composed of a plurality of optical switching elements arranged in a matrix.

According to the present invention, the optical switch is composed of a plurality of optical switch elements arranged in a matrix.

The electric / optical shared path switching device according to the next invention is characterized in that, in the above-mentioned invention, the capability of the error correction code is changed according to the specifications of the optical switch.

According to the present invention, the capability of the error correction code is changed according to the specifications of the optical switch.

The electric / optical shared path switching device according to the next invention is characterized in that, in the above invention, the specifications of the optical switch to be used are set according to the capability of the error correction code.

According to the present invention, the specifications of the optical switch to be used are set according to the capability of the error correction code.

The electric / optical shared path switching device according to the next invention is characterized in that, in the above-mentioned invention, the same bit rate as the external transmission data is used for the transmission data in the device.

According to the present invention, the same bit rate as the externally transmitted data is used for the internally transmitted data.

In the above invention, an electric / optical shared path switching device according to the next invention has an electric switch for switching a transmission path, and transmits transmission data from a plurality of transmission paths of a lower layer to the electric switch. A multiplexing processing unit provided therein multiplexes the signals so that they have the same transmission speed as that of the receiving-side and transmitting-side terminating devices, and then converts the signals into optical signals and sends the signals to the optical switch. After converting an optical signal into an electric signal, the demultiplexing processing unit provided in the electric switch further includes a terminating device that demultiplexes the signal so that the transmission rate is the same as that of a lower layer, The feature is that add / drop can be performed between them.

According to the present invention, a terminating device for performing add / drop is further provided, and transmission data from a plurality of low-order layer transmission paths is provided in the electric switch by the multiplexing processing section, After multiplexing so that the transmission speed is the same as that of the transmission side terminating device, it is converted into an optical signal and sent to the optical switch, and a plurality of optical signals from the optical switch are converted into electric signals and then in the electric switch. The provided demultiplexing processing unit demultiplexes so as to have the same transmission rate as the lower layer.

[0033]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of an electric / optical shared path switching device according to the present invention will be described in detail below with reference to the accompanying drawings.

First Embodiment FIG. 1 is a block diagram showing a configuration of a first embodiment of a cross connect device according to the present invention.

This cross-connect device comprises a plurality of receiving side terminating devices (receiving side LTU: Line Terminate Unit) 10.
-1 to 10-n, an optical switch 20 that switches a transmission path in an optical area, and a plurality of transmission side termination devices (transmission side LT
U) 30-1 to 30-n and the network control device 40
It has and.

Each of the receiving-side LTUs 10-1 to 10-n converts a plurality of optical signals transmitted as external interfaces from the plurality of receiving-side optical transmission lines 8-1 to 8-m into electric signals. / Electric converters 1-1 to 1-m and external optical transmission lines 8-1 to 8-m built in these optical / electric converters 1-1 to 1-m and based on the converted electric signals. Monitoring units 2-1 to 2-m for monitoring the failure of the receiver and the receiving side LT
An electric switch 4 for electrically switching a transmission path in U and a plurality of outputs of the electric switch 4 for transmitting a large-capacity signal in the device are respectively converted into optical signals, and the converted optical signals are converted. A plurality of electric / optical conversion units 3-1 to 3-m for outputting to each input port of the optical switch 20 via the optical transmission line are provided.

The optical switch 20 includes a plurality of receiving LTU1s.
A plurality of input ports to which the plurality of electric / optical conversion units 3-1 to 3-m respectively included in 0-1 to 10-n are respectively connected,
The optical path is used to switch the transmission path between the plurality of output ports to which the plurality of optical / electrical conversion units 5-1 to 5-m respectively included in the plurality of transmission side LTUs 30-1 to 30-n are separately connected. This is what you do with. As the optical switch 20, for example, a system having a plurality of optical switch elements arranged in a matrix and spatially controlling an optical path to switch a transmission path is adopted. In addition, an optical switch 20 using a dielectric multi-layer film filter, a wavelength multiplexing / demultiplexing device such as a WDM coupler, a fiber grating, and an arrayed waveguide grating is used.
May be configured.

The plurality of output ports of the optical switch 20 are m
This unit is connected to a plurality of transmission-side LTUs 30-1 to 30-n. Each of the transmitting-side LTUs 30-1 to 30-n includes optical / electrical converting units 5-1 to 5-m that convert an optical signal output from each output port of the optical switch 20 into an electrical signal, and the transmitting-side LTU. And an electrical switch 6 for electrically switching the transmission path, and a plurality of outputs of the electrical switch 6 are converted into optical signals, and the converted optical signals are transmitted on the transmission side optical transmission lines 9-1 to 9-m. To a plurality of electric / optical conversion units 7-
1 to 7-m.

The network controller 40 has a routing table in which transmission paths for switching the electric switches 4 and 6 and the optical switch 20 are set. Further, the network control device 40 uses the receiving-side termination device 10
-1 to 10-n, the transmission paths are reset by judging the states of the optical transmission lines 8-1 to 8-m based on the monitoring information from the respective monitoring units 2-1 to 2-m. Switching of the electric switches 4 of the plurality of receiving side terminating devices 10-1 to 10-n, the electric switches 6 of the plurality of transmitting side terminating devices 30-1 to 30-n, and the optical switch 20 according to the setting contents. Execute control.

Next, the operation will be described. The external optical transmission data received via the plurality of optical transmission lines 8-1 to 8-m on the receiving side is the same as that of the optical signals in the LTUs 10-1 to 10-n on the receiving side.
The electric conversion units 1-1 to 1-m convert the electric signals.
The transmission data converted into the electric signal is sent to each of the monitoring units 2-1 to 2-1.
The fault information is read at 2-m, and the read fault information is notified to the network control device 40. The network control device 40 determines the state of each optical transmission line based on this failure information, sets a required transmission path, and receives LTUs 10-1 to 10-on the receiving side according to the set transmission path.
The electrical switch 4 in n, the optical switch 20, and the transmitting side L
The electric switches 6 in the TUs 30-1 to 30-n are switched and controlled.

Therefore, the optical / electrical converters 1-1 to 1-
The transmission data converted into the electric signal by m is transmitted through the transmission path of the electric switch 4, the optical switch 20 and the electric switch 6 set by the network control device 40 to the electric / electrical
Passes while converting light to electricity.

That is, for example, the receiving side LTU 10-1
The transmission data received by the receiving LTU 10-1
By switching the electric switch 4 in the
10-1 is sent to any of the plurality of electric / optical conversion units 3-1 to 3-m, and further, the electric / optical conversion units 3-1 to 3-m.
After being converted into an optical signal by, the signal is input to the input port of the optical switch 20. The transmission data is transmitted to a plurality of transmission-side LTUs 30-1 to 30-n via the output ports of the optical switch 20 by switching a plurality of optical switch elements arranged in a matrix in the optical switch 20. light/
It is sent to any of the electric conversion units 5-1 to 5-m. Then, for example, the transmission data received by the transmission-side LTU 30-n is converted into an electric signal by any of the optical / electrical conversion units 5-1 to 5-m, and then the electric switch of the transmission-side LTU 30-n. 6 is input. Furthermore, this transmitted data is
When the electric switch 6 is switched, it is input to any of the plurality of electric / optical conversion units 7-1 to 7-m in the LTU 30-n, converted into an optical signal for external transmission there, and then transmitted to the transmission side. It is sent to the plurality of optical transmission lines 9-1 to 9-m.

As described above, in the first embodiment, the electric switches 4 of the receiving side LTUs 10-1 to 10-n.
And switching of electrical transmission paths by the electrical switches 6 of the transmitting side LTUs 30-1 to 30-n, and the optical switch 20.
Since the transmission path switching is performed by cooperating with the switching of the transmission path in the optical area by means of the redundant demultiplexing, electrical / optical conversion is reduced and demultiplexing, which was conventionally required to process electrical signals, is performed. The processing unit, the parallel distributed processing unit, and the multiplexing processing unit can be removed, which greatly reduces the electronic circuit and contributes to downsizing of the device, low cost, and low power consumption.

In FIG. 1, each terminating device is divided into a receiving side and a transmitting side for the sake of convenience. However, each terminating device may be provided with necessary components so that transmission and reception can be performed. Good.

Second Embodiment Next, a second embodiment of the present invention will be described with reference to FIGS. In the second embodiment, the quality control, the connection monitoring, and the protection function, which are comparable to the switching by the electric signal, can be realized even by the switching in the optical region by the optical switch 20. The optical switch currently in practical use switches the path by spatially controlling the optical path. Such an optical switch has variations in repeatability and has driving parts,
Connection error may occur.

Therefore, in the cross-connect device shown in FIG. 2, the optical signal monitoring section 50 for monitoring the power of the optical signal is installed at the input port and the output port of the optical switch 20. Therefore, if the monitoring information of the optical signal monitoring unit 50 is sent to the network control device 40, a connection error in the optical switch 20 can be surely detected, and this information can be used for setting a transmission path. If so, more reliable path switching can be realized. The optical signal monitoring unit 50 can be arranged inside the optical switch 20.

Further, in the cross-connect device shown in FIG. 3, the supervisory control information insertion units 11-1 to 11-1 to the electric / optical conversion units 3-1 to 3-m of the receiving side LTUs 10-1 to 10-n are provided.
11-m are provided respectively, and the transmitting side LTU 30-1
˜30-n optical / electrical converters 5-1 to 5-m are provided with monitoring control information monitoring units 12-1 to 12-m, respectively. In the supervisory control information insertion units 11-1 to 11-m,
At the stage of the electric signal, the supervisory control information of 1 to several bits is periodically inserted into the transmission data, and the electric signal into which this supervisory control information is inserted is converted into an optical signal. The monitoring control information monitoring units 12-1 to 12-m detect the disconnection of the optical signal or the connection error by reading the monitoring control information in the transmission data converted from the optical signal to the electrical signal. That is, when the supervisory control information different from the inserted supervisory control information is received, it can be determined that the optical switch 20 is disconnected or has a connection error. The detection results of the monitoring control information monitoring units 12-1 to 12-m are sent to the network control device 40. Therefore, if this detection result is used to set the transmission path, more reliable path switching can be realized.

Next, in the cross-connect device shown in FIG. 4, the optical switch 20 is replaced with the working optical switch 20a.
And a standby system optical switch 20b. Also,
Electric / optical conversion unit 3- of the receiving side LTUs 10-1 to 10-n 3-
1 to 3-m are provided with FEC adding units 13-1 to 13-m for adding an error correction code (FEC: Forward Error Correct) to the optical signal transmitted to the optical switch 20, and the transmitting side LTU 30-1 to The FEC determining units 14-1 to 14-1 to determine the deterioration status of signals by decoding (deciphering) the FEC code in the optical / electrical converting units 5-1 to 5-m of 30-n.
14-m is provided.

Next, the operation will be described. The external optical transmission data received via the plurality of optical transmission lines 8-1 to 8-m on the receiving side is the same as that of the optical signals in the LTUs 10-1 to 10-n on the receiving side.
The electric conversion units 1-1 to 1-m convert the electric signals.
The transmission data converted into the electric signal is sent to each of the monitoring units 2-1 to 2-1.
The fault information is read at 2-m, and the read fault information is notified to the network control device 40. The network control device 40 judges the state of each optical transmission line based on this failure information, sets a required transmission path, and receives LTUs 10-1 to 10-on the receiving side according to the set transmission path.
The electrical switch 4 in n, the optical switch 20, and the transmitting side L
The electric switches 6 in the TUs 30-1 to 30-n are switched and controlled. Therefore, the transmission data converted into electric signals by the optical / electrical conversion units 1-1 to 1-m are transmitted through the transmission paths of the electric switch 4, the optical switch 20, and the electric switch 6 set by the network control device 40 to the electric path. /light/
Passes while performing electrical conversion, and LTU30-1 on the transmission side
The signals are transmitted from the electric / optical conversion units 7-1 to 7-m in 30-n to the plurality of optical transmission lines 9-1 to 9-m on the transmission side.

Here, the receiving side LTUs 10-1 to 10-n
FEC adding section 13-of the electric / optical converting section 3-1 to 3-n
1 to 13-m are F at the stage of electric signal for transmission data.
EC code is added. The transmission data to which the FEC code has been added is converted into an optical signal, then passes through the active optical switch 20a and is sent to the transmitting side LTUs 30-1 to 30-n.
Optical / electrical conversion unit 5-of the transmitting side LTUs 30-1 to 30-n 5-
In 1 to 5-m, an optical signal is converted into an electric signal. Also,
The FEC determining units 14-1 to 14-m determine the deterioration state of the signal by extracting the FEC code in the transmission data converted into the electric signal and decoding the FEC code.
This determination information is sent to the network control device 40. Therefore, when the network control device 40 determines from this determination information that a connection abnormality or a failure has occurred, it outputs a switching instruction signal to the optical switch 20 from the active optical switch 20a to the standby optical switch 20b. Then, in response to this switching instruction signal, the optical switch 20
It is switched to the standby optical switch 20b.

As described above, according to the cross-connect device of FIG. 4, the FEC code is added to the signal transmitted to the optical switch and is decoded, so that quality control is performed even when the optical level is switched. And connection monitoring can be done. Also, a protection function can be realized by combining with a spare optical switch.

If the optical switches 20 are arranged in a matrix and the lines of the standby system are shared, the scale of the optical circuit is made much larger than in the case where the active system and the standby system are provided in a one-to-one relationship. The protection function can be realized without

By the way, in a large-scale electric / optical shared cross-connect device, it is necessary to provide a large-scale optical switch or connect small-scale optical switches in multiple stages.
A large-scale optical switch or a small-scale optical switch connected in multiple stages causes large optical loss and poor reproducibility of repeatability, which causes the system to become unstable. Therefore, if the FEC capability is changed according to the specifications (capacity) of the optical switch, a large-scale optical switch can be supported.

On the contrary, if the specifications such as the optical loss and the repeatability required for the optical switch are determined according to the FEC capability, the optimum electrical / electrical ratio matching the transmission speed can be obtained.
An optical shared cross-connect device can be created.

Further, if the same bit rate as the external transmission data is used for the internal transmission data, it is possible to process with the same clock in the electrical / optical shared cross-connect device without using a plurality of clocks. The number of electronic circuits can be reduced.

As described above, if the FEC capability is optimized according to the specifications (capacity) of the optical switch, or conversely, the optical switch is optimized according to the FEC capability, the optimum system is obtained. An electric / optical shared cross-connect device can be obtained. Further, if the same bit rate as the external transmission data is used for the internal transmission data, the number of electronic circuits can be reduced and the cost efficiency can be further improved.

Third Embodiment Next, a third embodiment of the present invention will be described with reference to FIG. This Embodiment 3
In order to add the add / drop function, the terminating device 60 capable of transmitting and receiving is provided. Addition / drop of transmission data is executed between the optical switch 20 and the terminating device 60.

The terminating device 60 has external interfaces (external I / Fs) 21-1 to 21-x and external I / Fs 21-1 to 21-x which are interfaces with low-speed transmission lines of lower layers.
21-x, a monitoring unit 22 that monitors a failure of an external transmission line of a lower layer, an electric switch 23 that electrically switches a destination of a signal, and an electric switch 23 that is built in to detect an electric signal of a lower layer. And a multiplexing / demultiplexing processing unit 25 that makes the electrical signal of the higher layer higher (multiplex) and lowers the electrical signal of the higher layer to the electrical signal of the lower layer (demultiplex). , FEC addition determination units 15-1 to 15-
It has the electro-optical conversion units 24-1 to 24-y with y.
The electrical / optical conversion units 24-1 to 24-y include the optical switch 20.
The optical signal from the optical switch is converted into an electric signal and the electric signal sent to the optical switch 20 is converted into an optical signal.

Next, the operation will be described. The transmission data of the lower layer (electrical signal in this case) received from the lower layer transmission line is transmitted to the other terminating devices 10-1 to 10-n and 30-1 at the multiplexing / demultiplexing processing unit 25. 30-n
Are multiplexed so that the transmission speed becomes the same. The multiplexed transmission data is converted into an electric signal by the electric / optical conversion unit (any of 24-1 to 24-y) of the port to which it is added. The multiplexed transmission data is input to the optical switch 20 and added in the optical switch 20. In this case, the multiplexing / demultiplexing processing unit 25 causes the other terminating device 10-
Since they are multiplexed so as to have the same transmission rate as 1 to 10-n and 30-1 to 30-n, the add processing can be reliably performed by the optical switch 20.

On the other hand, the higher layer transmission data dropped by the optical switch 20 is converted into an electrical signal by the electrical / optical conversion unit (any of 24-1 to 24-y) of the port of the terminating device 60 to be dropped. Then, the data is converted into lower layer transmission data by the multiplexing / demultiplexing processing unit 25.
Then, the converted lower layer transmission data is converted into the external I
/ F21-1 to 21-x to the lower layer transmission path.

As described above, according to the third embodiment, the transmission data of the lower layer is multiplexed into the transmission signal of the higher layer, and then converted into an optical signal for add processing, and the dropped higher layer is also processed. Since the transmission signal is converted to an electrical signal and then demultiplexed to convert it to a lower layer signal, a huge amount of electronic circuits can be removed, thus reducing the size and power consumption of the device. Therefore, it is possible to provide an electric / optical shared cross-connect device having an add / drop function at a low cost.

In the third embodiment, the terminating device 6
The external interface of 0 is an electric line, but if an electric / optical conversion unit is further provided in the terminating device, it can be applied to an optical line.

The present invention is also based on WDM (wavelength division multiplexing).
The present invention can also be applied to a cross-connect device that performs line control for allocating the optical signal sent by the method to different output fibers for each wavelength or an ADM device that supports wavelength multiplexing.

[0064]

As described above, according to the present invention, the electric transmission path is switched by the electric switch of the receiving side terminating device and the electric switch of the transmitting side terminating device,
Since the transmission path switching is performed by cooperating the switching of the transmission path in the optical area by the optical switch, redundant electrical / optical conversion is reduced and the multiplexing required for processing the electrical signal is performed. The demultiplexing processing unit, the parallel distributed processing unit, and the multiplexing processing unit can be removed, which significantly reduces the electronic circuit, and contributes to downsizing of the device, low cost, and low power consumption.

According to the next invention, the failure of the external transmission data is monitored, and the switching of the electric switch of the receiving side terminating device, the electric switch of the transmitting side terminating device and the optical switch is controlled based on the monitoring result. Therefore, the transmission path can be set according to the failure state of the optical transmission path.

According to the next invention, the connection state in the optical switch is monitored by monitoring the power of the optical signal input to and output from the optical switch. Therefore, a connection error in the optical switch can be prevented. It can be detected reliably, and if this information is used to set the transmission path, more reliable path switching can be realized.

According to the next invention, the monitoring control information is periodically inserted into the optical signal input to the optical switch, and the monitoring control information contained in the optical signal output from the optical switch is monitored, Since the connection status in the optical switch is monitored, disconnection and connection error in the optical switch can be reliably detected, and if this information is used to set the transmission path, higher reliability can be achieved. Path switching can be realized.

According to the next invention, the error correction code is added to the optical signal input to the optical switch, and the error correction code included in the optical signal output from the optical switch is decoded, whereby in the optical switch. By monitoring the connection status of the optical switch, disconnection and connection error in the optical switch can be reliably detected, and if this information is used to set the transmission path, more reliable path switching is realized. it can.

According to the next invention, when the failure occurs, the working optical switch is switched to the spare optical switch, so that the optical switch can be provided with a protection function.

According to the next invention, the optical switch is composed of a plurality of optical switch elements arranged in a matrix, and the standby system can be shared.

According to the next invention, since the ability of the error correction code is changed according to the specification (ability) of the optical switch, even if an optical switch having a problem of repeatability is used under the present circumstances. It will also be possible to support large-scale optical switches.

According to the next invention, since the specifications of the optical switch to be used are set according to the capability of the error correction code, it is possible to obtain the optimum cross-connect function for the required transmission speed.

According to the next invention, since the same bit rate as the external transmission data is used for the transmission data in the device, it is possible to use the same clock without using a plurality of clocks in the device. Therefore, the number of electronic circuits can be further reduced, and cost efficiency can be further improved.

According to the next invention, a terminal device for performing add / drop is further provided, and the transmission data of the lower layer is multiplexed to the transmission signal of the higher layer and then converted into an optical signal for path switching control. Therefore, it is possible to remove a huge amount of electronic circuits, reduce the size of the device, reduce power consumption, and provide a low-priced cross-connect device having an add / drop function.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of an electric / optical shared cross-connect device according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a configuration of an electric / optical shared cross-connect device according to a second embodiment of the present invention.

FIG. 3 is a diagram showing another configuration of the electric / optical shared cross-connect device according to the second embodiment of the present invention.

FIG. 4 is a diagram showing another configuration of the electric / optical shared cross-connect device according to the second embodiment of the present invention.

FIG. 5 is a diagram showing another configuration of the electric / optical shared cross-connect device according to the third embodiment of the present invention.

FIG. 6 is a configuration diagram of a cross-connect device according to a conventional technique.

[Explanation of symbols]

1 optical / electrical conversion unit, 2 monitoring unit, 3 electric / optical conversion unit, 4 electric switch, 5 optical / electrical conversion unit, 6 electric switch, 7 electric / optical conversion unit, 8, 9 optical transmission line, 1
0 receiving side terminating device, 11 supervisory control information inserting section, 12
Monitoring control information monitoring unit, 13 FEC addition unit, 14 F
EC determination unit, 15 FEC addition determination unit, 20 optical switch, 20a (current system) optical switch, 20b standby system optical switch, 21 external interface, 22 monitoring unit,
23 Electric Switch, 24 Electric / Optical Converter, 25
Multiplexing / demultiplexing processing unit, 30 transmission side terminating device, 4
0 network controller, 50 optical signal monitor, 60
Termination device.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Seiji Kozaki             2-3 2-3 Marunouchi, Chiyoda-ku, Tokyo             Inside Ryo Electric Co., Ltd. (72) Inventor Hiroshi Ichigase             2-3 2-3 Marunouchi, Chiyoda-ku, Tokyo             Inside Ryo Electric Co., Ltd. F-term (reference) 5K002 AA07 BA06 DA13 FA01                 5K069 DB07 DB32 DB33 EA22 HA01                       HA08 HA09

Claims (11)

[Claims] 1. A plurality of first optical / electrical conversion units for converting an optical signal from a plurality of optical transmission lines into an electric signal, and transmission path switching of the plurality of optical / electrically converted electric signals by the termination. A first electric switch that is electrically operated in the device, and a plurality of first electric / optical devices that convert a plurality of electric signals switched and output by the first electric switch into optical signals and output the optical signals to an optical switch. A plurality of receiving-side terminating devices having a converter, a plurality of second optical / electrical converters for converting a plurality of optical signals input from the optical switch into electric signals, and a plurality of the optical / electrically converted plurality Second electric switch for electrically switching the transmission path of the electric signal, and a plurality of electric signals switched and output by the second electric switch are respectively converted into optical signals and transmitted to a plurality of optical transmission paths. A transmission side terminating device having a second electric / optical conversion unit; Between a plurality of first electric / optical converters included in the plurality of receiving side terminating devices and a plurality of second optical / electrical converting units included in the plurality of transmitting side terminating devices, respectively. The optical switch for switching the transmission path in the optical area, and the electrical switch of the plurality of receiving side terminating devices and the electrical switch of the plurality of transmitting side terminating devices according to the set transmission path. A switch and a network control device that controls switching of the optical switch, and a shared electric / optical path switching device. 2. The first optical / electrical conversion unit includes a monitoring unit that monitors a fault in external transmission data and notifies the network control device of the monitoring result. Setting the transmission path based on the monitoring result from the monitoring unit, and switching control of the electric switches of the plurality of receiving side terminating devices, the electric switches of the plurality of transmitting side terminating devices, and the optical switch according to the setting contents. The electric / optical shared path switching device according to claim 1, wherein 3. The electric / optical shared use according to claim 1, wherein an optical signal monitoring unit for monitoring the power of the optical signal is provided in the input port or the output port of the optical switch or in the optical switch. Route switching device. 4. A supervisory control information insertion unit that periodically inserts supervisory control information into an optical signal input to the optical switch, and monitors the supervisory control information included in the optical signal output from the optical switch. The electric / optical shared path switching device according to claim 1 or 2, further comprising: a monitoring control information monitoring unit. 5. An error correction code adding section for adding an error correction code to an optical signal input to the optical switch, and an error correction code decoding for decoding an error correction code included in an optical signal output from the optical switch. The electric / optical shared path switching device according to claim 1 or 2, further comprising: 6. The optical switch according to claim 1, wherein the optical switch has a spare optical switch, and the network control device switches from the working optical switch to the spare optical switch when a failure occurs. The electric / optical shared path switching device according to any one of the above. 7. The electric / optical shared path switching device according to claim 1, wherein the optical switch includes a plurality of optical switch elements arranged in a matrix. . 8. The capability of the error correction code is changed according to the specifications of the optical switch.
An electric / optical shared path switching device according to any one of 1. 9. The specification of the optical switch to be used is set according to the capability of the error correction code.
7. The electric / optical shared path switching device according to any one of 7. 10. The electric / optical shared path switching device according to claim 1, wherein the same bit rate as the external transmission data is used for the transmission data in the device. 11. A receiving side and a transmitting side terminating device having an electric switch for switching a transmission path, wherein transmission processing data from a plurality of lower-layer transmission lines is provided by a multiplexing processing unit provided in the electric switch. After being multiplexed so as to have the same transmission speed as the above, the optical signal is converted into an optical signal and sent to the optical switch, and a plurality of optical signals from the optical switch are converted into electric signals and then provided in the electric switch. The demultiplexing processing unit is further provided with a terminating device for demultiplexing so as to have the same transmission rate as that of a lower layer, and add / drop can be performed with the optical switch. The shared electric / optical path switching device according to any one of 1 to 10.