JP2001144693A - Optical submarine cable system and terminal station in the optical submarine cable system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify and miniaturize the configuration of a terminal station device in the optical submarine cable system and to facilitate the maintenance of the terminal station device. SOLUTION: A communication center 200 is provided with an ADM 24 and an LET(line terminator) 25. The communication center 200 transmits a wavelength multiplex optical signal to a terminal station 160 through a land channel 500. The signal sent through the land channel 500 is given to a terminal station 100, where waveform shaping and amplification are applied to the signal and the resulting signal is sent to an optical submarine cable. The terminal station 100 is installed with a 3R repeater 10. The 3R repeater 10 includes an optical transmission 3R circuit and also a wavelength multiplex/demultiplex function and a dispersion compensation fiber function. The configuration of the 3R repeater 10 is simpler than that of the LTE including many SLTE sets with a large frame size and having many additional functions. Thus, the terminal station 100 is simplified more in comparison with the configuration of a conventional terminal station including the LTE.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a terminal station in an optical submarine cable system installed near a seashore for relaying between an optical submarine cable and a land line.

[0002]

2. Description of the Related Art FIG. 6 is a system configuration diagram showing one configuration example of a conventional optical submarine cable system. In FIG. 6, the optical submarine cable is usually accommodated in a terminal 15 built within a few km from the shore. In addition, the optical submarine cable is a beach manhole (BM) 300 provided on the coast.
, Power is supplied from the power supply device 18 in the terminal station 15. Hereinafter, a portion of the optical submarine cable accommodated in the terminal station 15 on the sea side from the beach manhole 300 is referred to as a submarine cable 520, and a portion on the land side from the beach manhole 300 is referred to as a land cable 510.

In the system shown in FIG. 6, a plurality of lines from users in an urban area or the like are aggregated at the terminal station 15. In this example, the SDH multiplex system is used.
Therefore, each line from the user is collected into a plurality of tributary (TRB) s 21, 22, and 23, and the ADM (A
dd Drop Multiplexer) 24. Each of the tributaries 21, 22, 23 is, for example, S
This is a concept corresponding to TM-N. The ADM 24 has different speed tributaries 21, 22, 23 (STM-
N) and multiplexes the wavelength-division multiplexed optical signal into a line terminator (Li).
ne Terminal Equipment: LT
E) Give it to 19. The LTE 19 amplifies and shapes the wavelength-division multiplexed optical signal, and then sends the wavelength-division multiplexed optical signal to the land cable 510.

The wavelength-division multiplexed optical signal transmitted through the submarine cable 520 and the land cable 510 undergoes processing opposite to the above processing at the terminal station 15, and is separated as a tributary (TRB) into lines to users in various places. And forwarded to users around the world.

[0007] The system shown in FIG. 6 is a configuration in which lines from various places are aggregated in the terminal station 15. Since the terminal station 15 is installed near the coast, maintenance is inconvenient. Further, since each line from the user must be laid to the terminal station 15, the cost increases. As a method for solving such inconvenience, a communication center accommodating each line from a user is provided in an urban area, some multiplexing is performed at the communication center, and a multiplexed signal is transmitted from the communication center to a terminal station. There is a method.

FIG. 7 is a system configuration diagram showing a configuration example of a conventional optical submarine cable system in which a communication center 200 is provided separately from a terminal station 160. In the system shown in FIG. 7, the communication center 200
DM24 and LET25 are provided. And
The wavelength multiplexed optical signal is transmitted from the communication center 200 to the land line 50.
0 is transmitted to the terminal station 160. The land line is called the backhaul line. The signal transmitted on the backhaul line 500 is subjected to waveform shaping and amplification in the terminal station 160, and then transmitted to the optical submarine cable.

[0007] As shown in FIG.
The LTE 25 is provided on the backhaul line 500 side in FIG. Backhaul line 5 at terminal station 160
The LTE 191 is also provided on the 00 side. That is,
LT between the communication center 200 and the terminal station 160
Relay processing by E25 and 191 is performed. Also,

An LTE 195 is provided on the optical submarine cable side of the terminal station 160. Therefore, the other terminal 4
Between 00 and 00, relay processing by LTE 195 is performed. Therefore, in the system shown in FIG. 7, the land-side system via the backhaul line and the sea-side system via the optical submarine cable are respectively so-called complete systems.

FIG. 8 shows the LTE 25, 19 shown in FIG.
It is a block diagram which shows the example of a structure of 1,195. The LTE 25 of the communication center 200 has an SLTE (Submarine LTE) having a waveform shaping and amplification function. Here, a case where 32 waves are wavelength-multiplexed is taken as an example. FIG.
Each of the SLTEs shown in FIG. 2 houses a circuit for two waves. Each SLTE is a device for long-distance optical transmission, and has an additional function of an error correction code (FEC). Each S
The optical signal processed by LTE is transmitted to a wavelength multiplexing / demultiplexing device 25.
1A, 251B, and backhaul line 500
Sent to In FIG. 8, the ADM 24 shown in FIG.
Are separately shown.

The wavelength multiplexed optical signal transmitted from the terminal station 160 via the backhaul line 500 is separated by the wavelength multiplexing / demultiplexing devices 251 and 252. Then, after an error correction operation is performed in each SLTE, an AD that processes each signal is processed.
Transferred to M24. Note that signals for two transmission / reception waves are input / output to / from each SLTE.
On one side, the transmission signal and the reception signal are simply displayed as one signal. Further, the wavelength multiplexing / demultiplexing device 2
51A and 251B each perform demultiplexing processing of 16 waves. Then, the wavelength multiplexing / demultiplexing device 251A remultiplexes the 16-wave multiplex signal and separates the 32-wave multiplex signal into the 16-wave multiplex signal.

In the LTE 191 of the terminal station 160, the wavelength division multiplexed optical signal from the backhaul line 500
The separation is performed by the separation devices 192A and 192B, and the above-described processing is performed in each SLTE. Then, it is transferred to the LTE 195 on the marine system side.

In the LTE 195, each SLTE performs the above-described processing, and the peripheral devices 197A, 197B
Output an optical signal. The peripheral devices 197A and 197B are:
After performing dispersion correction processing or the like on each optical signal, each optical signal is output to the wavelength multiplexing / demultiplexing devices 198A and 198B.
The wavelength multiplexing / demultiplexing devices 198A and 198B multiplex each optical signal and transmit the wavelength multiplexed optical signal to a land cable 510 in an optical submarine cable.

The wavelength-division multiplexed optical signal received from the optical submarine cable is subjected to the reverse of the above-described processing, and is transferred to the ADM 24 of the communication center 200.

[0014]

As described above, the conventional optical submarine cable system has a backhaul line 5
Since the signal transmitted through 00 is relayed using SLTE for long-distance optical transmission, there are the following problems.

(1) At present, the frame size of each SLTE is 2000 mm in height, 800 mm in width, and 600 mm in depth.
And the terminal 160 requires a large floor area. (2) Further, since a large number of SLTEs are used, the terminal device has a complicated configuration, and the power consumption is large. (3) Further, as the configuration becomes complicated, the number of maintenance steps is increased, and the number of maintenance parts to be prepared is also diversified.

Therefore, the present invention provides an optical submarine cable system and an optical submarine cable system which can simplify and reduce the size of the terminal equipment and can easily maintain the terminal equipment. Aims to provide stations.

[0017]

SUMMARY OF THE INVENTION An optical submarine cable system according to the present invention comprises: a communication center for aggregating user lines and having a line terminator; a terminal station for housing the optical submarine cable;
An optical submarine cable system including a land line connecting a communication center and a terminal station, wherein the terminal station has a 3R relay having an optical transmission 3R circuit as a relay device for relaying between the optical submarine cable and the land line. A vessel is provided.

According to another aspect of the present invention, there is provided an optical submarine cable system in which a landside system including a line terminator and a submarine system for transmitting / receiving a signal to / from an optical submarine cable are relayed by a 3R repeater. It is characterized by.

An optical submarine cable system according to the present invention comprises:
If a ring architecture is used,
A 3R repeater corresponding to each of the plurality of optical submarine cables is provided.

The 3R repeater, for example, separates a wavelength-division multiplexed optical signal from the LTE side into respective waves, multiplexes each wavelength wave, and transmits the multiplexed wave to the LTE side;
An optical signal transmitting / receiving device that realizes the 3R function, a peripheral device including a function of compensating for dispersion of the optical signal, and a multiplexed optical signal from the peripheral device for transmission to an optical submarine cable and wavelength multiplexed light from the optical submarine cable. And a wavelength multiplexing / demultiplexing device that separates a signal and sends it to a peripheral device.

In the above configuration, the peripheral devices may be omitted depending on the configuration of the system.

3R at one or more points on the land line
A repeater may be installed.

In the optical submarine cable system according to the present invention, the terminal in the optical submarine cable system includes:
A relay device for relaying between the optical submarine cable and the land line is provided, and the relay device is a 3R repeater having a 3R circuit for optical transmission.

The 3R repeater, for example, separates a wavelength-division multiplexed optical signal from a terrestrial line into each wave, multiplexes each wavelength wave, and sends the multiplexed wave to the terrestrial line.
An optical signal transmitting / receiving device that realizes the 3R function, a peripheral device including a function of compensating for dispersion of the optical signal, and a multiplexed optical signal from the peripheral device for transmission to an optical submarine cable and wavelength multiplexed light from the optical submarine cable. And a wavelength multiplexing / demultiplexing device that separates a signal and sends it to a peripheral device.

In the above configuration, the peripheral devices may be omitted depending on the configuration of the system.

[0026]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a system configuration diagram showing one configuration example of an optical submarine cable system to which the present invention is applied. In the system shown in FIG. 1, the terminal station 100 is provided with a 3R repeater 10. The configuration other than the terminal station 100 is the same as the configuration shown in FIG.

The 3R repeater 10 includes a 3R circuit for optical transmission, and further includes a wavelength multiplexing / demultiplexing function (WME) and a dispersion compensating fiber / compensating light transmitting function (TPE).

The optical transmission 3R circuit equalizes and amplifies (Re-Shapi) which shapes and amplifies the signal waveform deteriorated in the optical transmission line.
ng) function, a timing reproduction (Re-Timing) function for reproducing a clock signal from a received signal, and a signal regeneration (Re-Gener) for recognizing an equalized and amplified signal by a reproduced clock signal and reproducing the signal as a digital signal.
a) having a function.

FIG. 2 is a block diagram showing a configuration example of the 3R repeater 10 of the terminal station 100 together with the communication center 200. The configuration of the communication center 200 is the same as that shown in FIG. However, FIG. 2 shows one wavelength multiplexing / demultiplexing device 251.

In the 3R repeater 10, the wavelength multiplexing / demultiplexing device 11 separates the wavelength multiplexed optical signal from the backhaul line 500 into each wave, multiplexes the waves of each wavelength, and sends the multiplexed wave to the backhaul line 500. . Optical signal transmission / reception circuit (OS / OR) provided corresponding to each wavelength wave
The optical signal transmission / reception 12A, 12B made up of realizes the 3R function. The peripheral devices 13A and 13B are provided with a dispersion compensating fiber /
A compensation light transmission function (TPE) function is realized. The wavelength multiplexing / demultiplexing devices 14A, 14B are connected to the peripheral devices 13A,
Each optical signal from 13B is multiplexed and transmitted to a land cable 510 in an optical submarine cable, and a wave of each wavelength is separated from the wavelength-division multiplexed optical signal from the land cable 510 and transmitted to peripheral devices 13A and 13B.

Here also, a case where 32 waves are wavelength-multiplexed is taken as an example. Further, the wavelength multiplexing / demultiplexing devices 14A, 1
4B performs demultiplexing processing of 16 waves each. Then, the wavelength multiplexing / demultiplexing device 14A remultiplexes the 16-wave multiplex signal and separates the 32-wave multiplex signal into the 16-wave multiplex signal.

Next, the operation will be described. Communication center 2
The optical signals that have been subjected to amplification processing and the like in each SLTE in the LTE 25 of 00 are multiplexed by the wavelength multiplexing / demultiplexing device 251 and transmitted to the backhaul line 500. Terminal station 100
, The wavelength multiplexing / demultiplexing device 11 of the 3R repeater 10
Converts the wavelength multiplexed optical signal from the backhaul line 500 to 3
Optical signal transmitting and receiving device 1
The signal is transmitted to each optical signal transmitting / receiving circuit in 2A and 12B.

Each optical signal transmitting / receiving circuit converts an input optical signal into an electric signal. And backhaul line 500
The signal waveform deteriorated by the above is shaped and amplified, a clock signal is reproduced from the received signal, and the shaped and amplified signal is identified by the reproduced clock signal and regenerated as a digital signal. Thereafter, the electric signal is converted into an optical signal. Each of the regenerated optical signals is transmitted to the peripheral devices 13A and 13B.
Is output to

Each of the peripheral devices 13A and 13B has, for example, a dispersion compensating fiber and performs processing for compensating for chromatic dispersion of the optical signal. In addition, the peripheral devices 13A and 13B perform control for transmitting compensation light when the line capacity has not reached the mounting capacity of the submarine repeater. Further, signal addition processing for monitoring each submarine equipment is performed.

Note that a basic system can be configured without installing the peripheral devices 13A and 13B.

Thereafter, each optical signal is output to the wavelength multiplexing / demultiplexing devices 14A and 14B. Wavelength multiplexing / demultiplexing device 14
A and 14B multiplex each optical signal and send a wavelength multiplexed optical signal to a land cable 510 in an optical submarine cable.

The wavelength division multiplexed optical signal from the optical submarine cable is
The wavelength division multiplexing / demultiplexing devices 14A and 14B separate the optical signals into optical signals of respective wavelengths and output the optical signals to the peripheral devices 13A and 13B. Each optical signal is subjected to dispersion compensation processing through the peripheral devices 13A and 13B, and then output to each optical signal transmitting and receiving circuit in the optical signal transmitting and receiving devices 12A and 12B.

Each optical signal transmitting / receiving circuit converts an input optical signal into an electric signal. Then, the signal waveform deteriorated by the optical submarine cable is shaped and amplified, a clock signal is reproduced from the received signal, and the shaped and amplified signal is identified by the reproduced clock signal to be regenerated as a digital signal. Thereafter, the electric signal is converted into an optical signal. Each regenerated optical signal is output to the wavelength multiplexing / demultiplexing device 11.
Thus, the quality of the signal degraded by the optical submarine cable is
The 3R repeater 10 recovers to some extent.

The wavelength multiplexed optical signal from the wavelength multiplexing / demultiplexing device 11 is transmitted to the communication center 200 via the backhaul line 500. In the communication center 200, the wavelength division multiplexing / demultiplexing device 251 separates the wavelength division multiplexed optical signal into optical signals of each wavelength and outputs the optical signals to each SLTE.

Each SLTE performs waveform shaping and amplification of the optical signal transmitted through the optical submarine cable and the backhaul line, and performs error correction based on the error correction code inserted on the side of the partner terminal station 400. Then, the optical signal processed in each SLTE is A
Sent to DM.

Each ADM converts the wavelength multiplexed optical signal input from the LTE 25 into each of the tributaries 21, 22,
Divide into 23. Each tributary 21, 22, 23,
The data is transmitted to users in various places as it is or after being separated into lower-speed lines.

FIG. 3 is an explanatory diagram for explaining the effect of the present invention. As shown in FIG.
The repeater realizes the 3R function, regenerates a signal from the sea floor side, and sends the signal to the LTE 25 of the communication center 200. The optical signal deteriorated by the optical submarine cable is
The quality is restored at TE25.

Further, as shown in FIG.
The 3R repeater realizes the 3R function, regenerates a signal from the land side (the communication center 200 side), and sends the signal to the optical submarine cable. Therefore, the quality of the optical signal degraded in the backhaul line is recovered by the 3R repeater and transmitted to the optical submarine cable. For example, as shown in FIG.
Even if the S / N of the optical signal that has reached S / N is deteriorated, the optical signal whose S / N has been raised by the 3R repeater 10 is transmitted to the optical submarine cable.

In the conventional optical submarine cable system, the land-side system and the sea-side system are complete systems, and are connected to each other. Therefore, the terminal station has S on both the land side and the sea side.
LTE had to be installed. However, this embodiment is characterized in that the land side and the sea side are regarded as one system. In such a case, the 3R repeater 10 can be installed in the terminal station 100 without providing LTE including many SLTEs.

The configuration of the 3R repeater 10 is simpler than the configuration of the LTE including a large number of SLTEs having a large frame size and many additional functions. Therefore, the configuration of the terminal station 100 in the above embodiment is simplified as compared with the configuration of the conventional terminal station. As a result, the power consumption of the terminal station 100 is also reduced, and maintenance is easier than in the conventional terminal station.

Since the quality of the signal from the seabed is improved in the terminal station 10, the backhaul line can be lengthened in this embodiment. However, if the distance between the terminal station and the communication center, that is, the terminal station and LTE is 3R
A longer case may be assumed to the extent that the quality compensation by the repeater 10 is insufficient. In such a case, another 3R repeater may be installed on the backhaul line 500 as shown in FIG. In the system shown in FIG.
Repeaters 103 and 104 are provided on backhaul line 500.

As shown in FIG. 4, in such a system, the S / N of the signal from the backhaul line 500 is 3R.
The improvement in the repeaters 103 and 104 allows the length of the backhaul line 500 to be longer.

FIG. 5 is a system configuration diagram showing an embodiment in which the present invention is applied to an optical submarine cable system using a ring architecture. When the ring architecture is used, the submarine cables 521 and 522 are landed at a plurality of landing points, and three to the terminal station 11 corresponding to the respective submarine cables 521 and 522.
R repeaters 101 and 102 are provided.

The land cables 511 and 512 of the optical submarine cable accommodated in the terminal station 110 are supplied with power by the beach manholes 301 and 302. The terminal station 110 and the communication center 210 are connected by land lines (backhaul lines) 501 and 502. The communication center 210 has submarine cables 521 and 52 respectively.
2 are provided.

The operation of each of the 3R repeaters 101 and 102 and other components is the same as in the above-described embodiment. In the system shown in FIG. 5, one or more 3R repeaters can be installed on the backhaul line 500.

[0051]

As described above, according to the present invention, a communication center that aggregates user lines and has a line terminator, a terminal station that houses an optical submarine cable, and a land line that connects the communication center and the terminal station. Since the optical submarine cable system including the above has a configuration in which a 3R repeater having an optical transmission 3R circuit is provided as a relay device for relaying between the optical submarine cable and the land line at the terminal station, The configuration of the terminal device can be simplified and downsized, and maintenance of the terminal device can be facilitated.

[0052] Further, even when the optical submarine cable system is a mode in which a land-based system including a line terminator and a submarine system that transmits and receives signals to and from the optical submarine cable are relayed by a 3R repeater, similarly, The configuration of the terminal device can be simplified and downsized, and the maintenance of the terminal device can be facilitated. In the conventional optical submarine cable system, the land-side system and the sea-side system were completed systems and were configured to be connected to each other. SLTE had to be installed on both sides. However, in the present invention, the land side and the sea side can be regarded as one system, and the
Is unnecessary.

[Brief description of the drawings]

FIG. 1 is a system configuration diagram showing one configuration example of an optical submarine cable system to which the present invention is applied.

FIG. 2 is a block diagram showing a configuration example of a 3R repeater of a terminal together with a communication center.

FIG. 3 is an explanatory diagram for explaining an effect of the present invention.

FIG. 4 is a system configuration diagram showing an example in which two 3R repeaters are installed on a backhaul line.

FIG. 5 is a system configuration diagram showing an embodiment when the present invention is applied to an optical submarine cable system using a ring architecture.

FIG. 6 is a system configuration diagram showing one configuration example of a conventional optical submarine cable system.

FIG. 7 is a system configuration diagram showing another configuration example of the conventional optical submarine cable system.

FIG. 8 is a block diagram illustrating a configuration example of LTE.

[Explanation of symbols]

 REFERENCE SIGNS LIST 10 3R repeater 11 wavelength multiplexing / demultiplexing device 12A, 12B optical signal transmitting / receiving device 13A, 13B peripheral device 14A, 14B wavelength multiplexing / demultiplexing device 18 power supply device 24 ADM 25 LTE (line terminating device) 100, 110 terminal station 200 communication center

Claims (9)

[Claims] 1. An optical submarine cable system comprising: a communication center that aggregates user lines and has a line terminator; a terminal station that houses an optical submarine cable; and a land line that connects the communication center and the terminal station. The terminal has a 3R circuit for optical transmission as a relay device for relaying between the optical submarine cable and the land line.
An optical submarine cable system comprising a repeater. 2. A land-based system including a line termination,
An optical submarine cable system in which a submarine system that transmits and receives signals to and from an optical submarine cable is relayed by a 3R repeater. 3. An optical submarine cable system using a ring architecture, the terminal station comprising:
The optical submarine cable system according to claim 1 or 2, further comprising an R repeater. 4. A 3R repeater separates a wavelength-division multiplexed optical signal from a line terminator into respective waves, multiplexes waves of each wavelength, and sends the resulting signal to the line terminator. An optical signal transmitting / receiving device for realizing the 3R function, and multiplexing an optical signal from the optical signal transmitting / receiving device to transmit the multiplexed optical signal to the optical submarine cable, and separating the wavelength multiplexed optical signal from the optical submarine cable to the optical signal transmitting / receiving device side 4. The optical submarine cable system according to claim 1, further comprising a wavelength multiplexing / demultiplexing device for transmitting. 5. An optical signal from an optical signal transmitting / receiving device is transmitted to a wavelength multiplexing / demultiplexing device on an optical submarine cable side via a peripheral device having a function of compensating for dispersion of the optical signal, and the wavelength multiplexing / demultiplexing device is transmitted. The optical submarine cable system according to claim 4, wherein the optical signal separated by the separating device is transmitted to the optical signal transmitting / receiving device via the peripheral device. 6. One or more points on the land line
6. The optical submarine cable system according to claim 1, further comprising an R repeater. 7. An optical submarine cable system, comprising: a terminal station having a relay device for relaying between an optical submarine cable and a land line, wherein the relay device is a 3R repeater having a 3R circuit for optical transmission. A terminal in an optical submarine cable system, characterized in that: 8. A 3R repeater realizes a wavelength multiplexing / demultiplexing device for separating a wavelength-division multiplexed optical signal from a land line into respective waves, multiplexing each wavelength wave, and transmitting the multiplexed wave to the land line, and a 3R function. An optical signal transmitting / receiving apparatus, and an optical signal transmitting / receiving apparatus that multiplexes an optical signal from the optical signal transmitting / receiving apparatus and sends the multiplexed optical signal to an optical submarine cable, and separates and separates a wavelength multiplexed optical signal from the optical submarine cable into respective waves. 8. A terminal station in an optical submarine cable system according to claim 7, further comprising a wavelength multiplexing / demultiplexing device for transmitting to a side. 9. An optical signal from an optical signal transmitting / receiving device is sent to a wavelength multiplexing / demultiplexing device on an optical submarine cable side through a peripheral device having a function of compensating for dispersion of the optical signal, and the wavelength multiplexing / demultiplexing device is transmitted. The terminal station in the optical submarine cable system according to claim 8, wherein the optical signal separated by the separating device is transmitted to the optical signal transmitting / receiving device via the peripheral device.