Wavelength band expansion device, optical transmission system, and wavelength band expansion method

Abstract

A wavelength band expansion device, an optical transmission system, and a wavelength band expansion method of the present invention use a unit provided with a wavelength division multiplexing coupler connected to an optical fiber, and a first wavelength selection switch for inputting / outputting, to / from the wavelength division multiplexing coupler, a plurality of first optical signals that are in a first wavelength band and transmitted over the optical fiber. An additional coupler connected between the optical fiber and the wavelength division multiplexing coupler is disposed, and a second wavelength selection switch for inputting / outputting, to / from the additional coupler, a plurality of second optical signals that are in a second wavelength band and transmitted over the optical fiber is disposed. A second wavelength band that does not overlap with the first wavelength band is set.

Description

Wavelength band expansion device, optical transmission system, and wavelength band expansion method

[0001] The present disclosure relates to a wavelength band extension device, an optical transmission system, and a wavelength band extension method.

[0002] Patent Document 1 discloses a technology relating to an optical add / drop device having a branching function unit connected to each WSS (Wavelength Selective Switch) that drops optical signals of multiple wavelengths among the optical signals of each wavelength transmitted to an optical fiber by wavelength division multiplexing, and a CD / CDC (Colorless and Directionless / Colorless, Directionless and Contentionless) function unit that transmits the optical signals branched by the branching function unit to multiple transponders.

[0003] Japanese Patent Application Laid-Open No. 2020-155924

[0004] According to the technology described in Patent Document 1, since the optical transmission band of the optical fiber is fixed, if a demand for wavelength resources exceeds the maximum number of wavelengths that can be accommodated by the optical fiber, it becomes necessary to expand the entire system and use additional optical fiber, which poses the problem of being unable to flexibly expand the wavelength band functionality in response to demand.

[0005] The present disclosure has been made in view of the above-mentioned problems, and aims to provide a wavelength band expansion device, an optical transmission system, and a wavelength band expansion method that are capable of flexibly expanding the functionality of wavelength bands in response to demand, even when a demand for wavelength resources exceeds the maximum number of wavelengths that can be accommodated by an optical fiber, while suppressing the expansion of the entire system and the additional use of optical fiber.

[0006] In order to solve the above-mentioned problems, a wavelength band expander according to the present disclosure is arranged in a unit including a wavelength division multiplexing coupler connected to an optical fiber and a first wavelength selective switch that inputs and outputs a plurality of first optical signals in a first wavelength band transmitted through the optical fiber to and from the wavelength division multiplexing coupler, and an add coupler connected between the optical fiber and the wavelength division multiplexing coupler, and a second wavelength selective switch that inputs and outputs a plurality of second optical signals in a second wavelength band transmitted through the optical fiber to and from the add coupler, where the first wavelength band and the second wavelength band do not overlap.

[0007] The optical transmission system according to the present disclosure includes a wavelength band extension device, a unit, and an optical fiber.

[0008] A wavelength band expansion method according to the present disclosure relates to a unit including a wavelength division multiplexing coupler connected to an optical fiber and a first wavelength selective switch that inputs and outputs a plurality of first optical signals in a first wavelength band transmitted through the optical fiber to and from the wavelength division multiplexing coupler, an additional coupler is disposed between the optical fiber and the wavelength division multiplexing coupler, and a second wavelength selective switch is disposed that inputs and outputs a plurality of second optical signals in a second wavelength band transmitted through the optical fiber to and from the additional coupler, and a second wavelength band that does not overlap with the first wavelength band is set.

[0009] According to the present disclosure, even if a demand for wavelength resources arises that exceeds the maximum number of wavelengths that can be accommodated by optical fiber, it is possible to suppress the expansion of the entire system and the additional use of optical fiber, and to flexibly expand the functionality of wavelength bands in accordance with demand.

[0010] 1A and 1B are diagrams illustrating a first and second configuration examples of a wavelength band extending device according to an embodiment of the present disclosure;

[0011] Next, embodiments of the present disclosure will be described in detail with reference to the drawings. In the description, the same components are designated by the same reference numerals and redundant description will be omitted.

[0012] [Description of the embodiment] Fig. 1 is a diagram illustrating a first configuration example of a wavelength band extender according to an embodiment of the present disclosure. In Fig. 1, the wavelength band extender includes add couplers 17 and 27 and a second wavelength selective switch WSS2. The wavelength band extender is disposed in a base unit BU (unit) that constitutes an optical transmission system, and extends the wavelength band of an optical signal transmitted and received by the base unit BU.

[0013] The base unit BU includes first wavelength selective switches WSS11 and WSS12, and wavelength division multiplexing couplers 13 and 23. In addition, the base unit BU may include various optical elements.

[0014] The first wavelength selective switch WSS11 transmits a plurality of first optical signals in a first wavelength band transmitted through the optical fiber FB1. The first wavelength selective switch WSS11 is connected to the optical fiber FB1 via a wavelength division multiplexing coupler 13.

[0015] Here, the first wavelength band is a wavelength band included in the C-band or L-band. The C-band is a wavelength band ranging from 1530 to 1565 nm, and optical fibers generally have the lowest loss in the C-band, which is a great advantage in long-distance transmission systems. The L-band is a wavelength band ranging from 1565 to 1625 nm.

[0016] For example, the first wavelength selective switch WSS11 dynamically switches any wavelength path of a wavelength-multiplexed optical signal transmitted through the optical fiber FB1 to any port.

[0017] Alternatively, the first wavelength selective switch WSS11 may be connected to the wavelength division multiplexing coupler 13 via a C-band amplifier AM11 and an L-band amplifier AM12. The amplifier AM11 amplifies the C-band optical signal and introduces it to the wavelength division multiplexing coupler 13. The amplifier AM12 amplifies the L-band optical signal and introduces it to the wavelength division multiplexing coupler 13.

[0018] The wavelength division multiplexing coupler 13 may be connected to the optical fiber FB1 via a coupler 15 and an additional coupler 17. Here, the coupler 15 may be connected to a supervisory control module MD that outputs a third optical signal transmitted through the optical fiber. The coupler 15 introduces the third optical signal from the supervisory control module MD into the optical fiber FB1.

[0019] The monitoring and control module MD is a module used to monitor the state of the base unit BU or to control the base unit BU.

[0020] The add coupler 17 is connected to a port P1 of the base unit BU, and introduces an optical signal input from the port P1 into the optical fiber FB1. For example, the add coupler 17 is connected between the optical fiber FB1 and the wavelength division multiplexing coupler 13. The add coupler 17 may also be connected between the optical fiber FB1 and the coupler 15.

[0021] The first wavelength selective switch WSS12 receives a plurality of first optical signals in a first wavelength band transmitted through the optical fiber FB2. The first wavelength selective switch WSS12 is connected to the optical fiber FB2 via a wavelength division multiplexing coupler 23.

[0022] For example, the first wavelength selective switch WSS12 dynamically switches any wavelength path of a wavelength-multiplexed optical signal transmitted through the optical fiber FB2 to any port.

[0023] Alternatively, the first wavelength selective switch WSS12 may be connected to the wavelength division multiplexing coupler 23 via a C-band amplifier AM21 and an L-band amplifier AM22. The amplifier AM21 amplifies the C-band optical signal and introduces it to the first wavelength selective switch WSS12. The amplifier AM22 amplifies the L-band optical signal and introduces it to the first wavelength selective switch WSS12.

[0024] The wavelength division multiplexing coupler 23 may be connected to the optical fiber FB2 via a coupler 25 and an additional coupler 27. Here, the coupler 25 may be connected to a supervisory control module MD to which a third optical signal transmitted through the optical fiber is input. The coupler 25 introduces the third optical signal from the optical fiber FB2 into the supervisory control module MD.

[0025] The add coupler 27 is connected to a port P2 of the base unit BU, and outputs an optical signal from the optical fiber FB2 from the port P2. For example, the add coupler 27 is connected between the optical fiber FB2 and the wavelength division multiplexing coupler 23. The add coupler 27 may also be connected between the optical fiber FB1 and the coupler 25.

[0026] The expansion unit EU includes a second wavelength selective switch WSS2. In addition, the expansion unit EU may include various optical elements.

[0027] The second wavelength selective switch WSS2 inputs and outputs a plurality of second optical signals in a second wavelength band transmitted through the optical fibers FB1 and FB2 to and from the add couplers 17 and 27.

[0028] For example, the second wavelength selective switch WSS2 may be connected to the add coupler 17 and transmit the second optical signal to the optical fiber FB1 via the add coupler 17.

[0029] The second wavelength selective switch WSS2 may be connected to the add coupler 17 via the amplifier AM31, the port P3 provided in the expansion unit EU, and the port P1. Here, the amplifier AM31 amplifies the optical signal in the second wavelength band and introduces it to the add coupler 17.

[0030] The second wavelength selective switch WSS2 may be connected to the add coupler 27 and receive the second optical signal from the optical fiber FB1 via the add coupler 27.

[0031] The second wavelength selective switch WSS2 may be connected to the additional coupler 27 via the amplifier AM32, the port P4 provided in the expansion unit EU, and the port P2. Here, the amplifier AM32 amplifies the optical signal in the second wavelength band and introduces it to the second wavelength selective switch WSS2.

[0032] Here, the first wavelength band and the second wavelength band are set so as not to overlap each other. For example, if the first wavelength band is a wavelength band included in the C band or the L band, the second wavelength band may be set to be a wavelength band included in the S band or the U band.

[0033] The S band is a wavelength band ranging from 1460 to 1530 nm, and the U band is a wavelength band ranging from 1625 to 1675 nm.

[0034] Additionally, the wavelength of the third optical signal input / output by the supervisory control module MD is set so as not to be included in the second wavelength band.

[0035] As described above, by disposing the expansion unit EU in the base unit BU, the wavelength band of the optical signals transmitted through the optical fibers FB1 and FB2 is expanded.

[0036] For example, when the base unit BU is used alone, the wavelength band of the optical signals transmitted through the optical fibers FB1 and FB2 is only the wavelength band included in the C band or the L band. On the other hand, when the expansion unit EU is used together with the base unit BU, the wavelength band of the optical signals transmitted through the optical fibers FB1 and FB2 includes the wavelength band included in the S band or the U band in addition to the wavelength band included in the C band or the L band.

[0037] [Modification] FIG. 2 is a diagram illustrating a second configuration example of a wavelength band extending device according to an embodiment of the present disclosure.

[0038] 2, the add coupler 19 is connected to the optical fiber FB1 via a coupler 15 that is connected between the optical fiber FB1 and the wavelength division multiplexing coupler 13. In particular, the add coupler 19 is connected between the optical fiber FB1 and the supervisory control module MD. The add coupler 19 is also connected to a port P1 of the base unit BU, and introduces an optical signal input from the port P1 into the optical fiber FB1.

[0039] The additional coupler 29 is connected to the optical fiber FB2 via a coupler 25 that is connected between the optical fiber FB2 and the wavelength division multiplexing coupler 23. In particular, the additional coupler 29 is connected between the optical fiber FB2 and the supervisory control module MD. The additional coupler 29 is also connected to a port P2 of the base unit BU, and outputs an optical signal from the optical fiber FB2 from the port P2.

[0040] According to the above configuration, the third optical signal input / output by the monitoring and control module MD reaches the second wavelength selective switch WSS2, but the second wavelength selective switch WSS2 may be configured to remove the third optical signal. Alternatively, the second wavelength selective switch WSS2 may be configured not to forward the third optical signal.

[0041] In the modified example, the first wavelength band and the second wavelength band are also set so as not to overlap, and the wavelength of the third optical signal input / output by the monitoring and control module MD is set so as not to be included in the second wavelength band.

[0042] As described above, by disposing the expansion unit EU in the base unit BU, the wavelength band of the optical signals transmitted through the optical fibers FB1 and FB2 is expanded.

[0043] [Optical Transmission System] The above-described wavelength band expander, base unit BU (unit), and optical fibers FB1 and FB2 constitute an optical transmission system. By including the wavelength band expander in the optical transmission system, the wavelength band of the optical signal transmitted through the optical fibers FB1 and FB2 is expanded.

[0044] As a result, even if demand for wavelength resources exceeds the maximum number of wavelengths that can be accommodated by optical fiber, it is possible to suppress the expansion of the entire system and the additional use of optical fiber, and to flexibly expand the functionality of the wavelength band according to demand.

[0045] [Effects of the embodiment] As described above in detail, the wavelength band extender according to the present disclosure is arranged in a unit including a wavelength division multiplexing coupler connected to an optical fiber and a first wavelength selective switch that inputs / outputs a plurality of first optical signals in a first wavelength band transmitted through the optical fiber to / from the wavelength division multiplexing coupler. The wavelength band extender includes an add coupler connected between the optical fiber and the wavelength division multiplexing coupler, and a second wavelength selective switch that inputs / outputs a plurality of second optical signals in a second wavelength band transmitted through the optical fiber to / from the add coupler, wherein the first wavelength band and the second wavelength band do not overlap.

[0046] This means that even if demand for wavelength resources exceeds the maximum number of wavelengths that can be accommodated by optical fiber, it is possible to suppress the expansion of the entire system and the additional use of optical fiber, and to flexibly expand the functionality of wavelength bands according to demand.

[0047] Furthermore, even if the demand for wavelength resources varies greatly for each wavelength section provided, the wavelength band that can be wavelength multiplexed can be expanded while minimizing the impact on users who use the system that provides optical communication services.

[0048] In the wavelength band extension device according to the present disclosure, the unit may further include a monitoring and control module that inputs and outputs a third optical signal transmitted through the optical fiber, and the wavelength of the third optical signal may be outside the second wavelength band, thereby enabling flexible functional expansion of the wavelength band without affecting the operation of the monitoring and control module.

[0049] In the wavelength band extension device according to the present disclosure, the additional coupler may be connected between the optical fiber and the monitoring and control module. This reduces the number of optical elements arranged on the path between the optical fiber and the wavelength division multiplexing coupler. As a result, loss occurring on the path between the optical fiber and the wavelength division multiplexing coupler can be reduced.

[0050] In the wavelength band extension device according to the present disclosure, the first wavelength band may be a wavelength band included in the C-band or the L-band, thereby enabling optical communication services to be provided using a wavelength band with low optical fiber loss.

[0051] In the wavelength band extension device according to the present disclosure, the second wavelength band may be a wavelength band included in the S band or the U band, thereby enabling flexible functional expansion of the wavelength band in response to demand even when a demand for wavelength resources exceeds the maximum number of wavelengths that can be accommodated by an optical fiber.

[0052] The present disclosure relates to an optical transmission system including a wavelength band extension device, a unit, and an optical fiber. The present disclosure also relates to a wavelength band extension method including a unit including a wavelength division multiplexing coupler connected to the optical fiber and a first wavelength selective switch that inputs and outputs a plurality of first optical signals in a first wavelength band transmitted through the optical fiber to and from the wavelength division multiplexing coupler. The present disclosure also relates to a wavelength band extension method including: providing an additional coupler connected between the optical fiber and the wavelength division multiplexing coupler; providing a second wavelength selective switch that inputs and outputs a plurality of second optical signals in a second wavelength band transmitted through the optical fiber to and from the additional coupler; and setting a second wavelength band that does not overlap with the first wavelength band.

[0053] This means that even if demand for wavelength resources exceeds the maximum number of wavelengths that can be accommodated by optical fiber, it is possible to suppress the expansion of the entire system and the additional use of optical fiber, and to flexibly expand the functionality of wavelength bands according to demand.

[0054] Furthermore, even if the demand for wavelength resources varies greatly for each wavelength section provided, the wavelength band that can be wavelength multiplexed can be expanded while minimizing the impact on users who use the system that provides optical communication services.

[0055] Although the contents of the present disclosure have been described above based on the embodiments, the present disclosure is not limited to these descriptions, and various modifications and improvements are possible, which will be apparent to those skilled in the art. The descriptions and drawings that form part of this disclosure should not be understood as limiting the present disclosure. Various alternative embodiments, examples, and operating techniques will be apparent to those skilled in the art from this disclosure.

[0056] Of course, the present disclosure includes various embodiments not described herein. Therefore, the technical scope of the present disclosure is defined only by the invention-specifying matters according to the scope of the claims that are appropriate from the above description.

[0057] 13, 23 Wavelength division multiplexing coupler 15, 25 Coupler 17, 19, 27, 29 Additional coupler AM11, AM12, AM21, AM22, AM31, AM32 Amplifier BU Base unit (unit) EU Expansion unit FB1, FB2 Optical fiber MD Monitoring and control module P1, P2, P3, P4 Port WSS11, WSS12 First wavelength selective switch WSS2 Second wavelength selective switch

Claims

1. A wavelength band expansion device disposed in a unit comprising: a wavelength division multiplexing coupler connected to an optical fiber; and a first wavelength selective switch that inputs and outputs a plurality of first optical signals in a first wavelength band transmitted through the optical fiber to and from the wavelength division multiplexing coupler, wherein the wavelength band expansion device comprises: an additional coupler connected between the optical fiber and the wavelength division multiplexing coupler; and a second wavelength selective switch that inputs and outputs a plurality of second optical signals in a second wavelength band transmitted through the optical fiber to and from the additional coupler, wherein the first wavelength band and the second wavelength band do not overlap.

2. The wavelength band extension device according to claim 1, wherein the unit further comprises a monitoring and control module for inputting and outputting a third optical signal transmitted through the optical fiber, and the wavelength of the third optical signal is not included in the second wavelength band.

3. The wavelength band expansion device according to claim 2, wherein the additional coupler is connected between the optical fiber and the monitoring and control module.

4. The wavelength band extension device according to claim 1, wherein the first wavelength band is a wavelength band included in the C band or the L band.

5. The wavelength band extension device according to claim 1, wherein the second wavelength band is a wavelength band included in the S band or the U band.

6. An optical transmission system comprising a wavelength band expansion device according to any one of claims 1 to 5, the unit, and the optical fiber.

7. A wavelength band expansion method for a unit comprising: a wavelength division multiplexing coupler connected to an optical fiber; and a first wavelength selective switch that inputs and outputs a plurality of first optical signals in a first wavelength band transmitted through the optical fiber to and from the wavelength division multiplexing coupler, the method comprising: arranging an additional coupler connected between the optical fiber and the wavelength division multiplexing coupler; arranging a second wavelength selective switch that inputs and outputs a plurality of second optical signals in a second wavelength band transmitted through the optical fiber to and from the additional coupler; and setting the second wavelength band so that it does not overlap with the first wavelength band.

Images