Optical transmission system, optical transmission method, and wavelength cross-connect device
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2025-12-01
- Publication Date
- 2026-03-04
AI Technical Summary
Conventional WXC devices require a large number of wavelength converters, many of which remain unused when not all optical signals need conversion, leading to inefficiency and economic waste, while insufficient converters result in reduced performance.
A WXC device with a wavelength conversion unit and controller that manages and controls the use of converters, allowing flexible allocation and sharing of converters among input ports, and bypasses converters when not needed, using ingress WSS for route switching.
Enables appropriate setting of converter numbers, reducing costs and maintaining performance by avoiding unnecessary conversions and optimizing converter usage.
Smart Images
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Abstract
Description
[Technical Field]
[0001] The present invention relates to a wavelength cross-connect device and a wavelength cross-connect method. [Background technology]
[0002] A wavelength cross-connect (WXC) device used in an optical transmission system switches (cross-connects) the optical signal input through an input port to an output port indicated by a set wavelength path. A wavelength selective switch (WSS) inside the WXC device outputs the wavelength-multiplexed signal light transmitted from the input port to an arbitrary output port according to the set wavelength path.
[0003] Furthermore, the constraint of wavelength continuity, which requires that an optical path transmit an optical signal continuously from the start point to the end point using the same wavelength, can now be avoided by using converters that convert the wavelength of the optical signal along the optical path. WXC devices equipped with wavelength converters have also been proposed. The wavelength-band inversion (WBI) described in Non-Patent Document 1 can suppress the degradation of transmission quality due to inter-band Raman scattering. The all-optical wavelength converters (AO-WCs) described in Non-Patent Document 2 can increase the amount of traffic that can be accommodated. [Prior art documents] [Non-patent literature]
[0004] [Non-Patent Document 1] H. Kawahara et.al., “Cancellation of Static and Dynamic Power Transitions induced by inter-band Stimulated Raman Scattering in C+L-band WDM Transmission,” 2020 Opto-Electronics and Communications Conference (OECC) (2020). [Non-patent document 2] M. Nakagawa et.al., “Adaptive Link-by-Link Band Allocation: A Novel Adaptation Scheme in Multi-Band Optical Networks,” 2021 International Conference on Optical Network Design and Modeling (ONDM) (2021). Summary of the Invention [Problem to be solved by the invention]
[0005] In a conventional configuration where converters are installed in a WXC device, a large number of converters are required for each input / output port of the WXC device. However, only a portion of the large number of converters are in operation, and if there are few optical signals that require wavelength conversion before or after passing through the WXC device, it is expected that many of the converters installed will not be used. In other words, it is not economical to provide an extra converter in the WXC device. On the other hand, if the WXC device does not have enough converters, there is a concern that the performance of the WXC device will be reduced.
[0006] Therefore, a main object of the present invention is to propose a configuration of a WXC device that allows the number of converters provided in the WXC device to be appropriately set. [Means for solving the problem]
[0007] In order to solve the above problems, the wavelength cross-connect device of the present invention has the following features. The present invention provides a wavelength cross-connect device having a wavelength conversion unit and a controller, The wavelength converting portion is an input wavelength switch that outputs optical signals obtained by demultiplexing optical signals input from each input port of the wavelength cross-connect device into individual wavelength bands to any one of a plurality of wavelength converters; the wavelength converter that converts the wavelength band of an optical signal input from each of the ingress wavelength switches that handles the optical signal input from each input port into another wavelength band and outputs the converted optical signal to the egress wavelength switch; an output wavelength switch that switches the direction of the optical signal input from the wavelength converter toward each output port of the wavelength cross-connect device, The controller manages whether each of the wavelength converters is in use or unused, and controls the ingress wavelength switch so as to output an optical signal to the wavelength converter that is unused. [Effects of the Invention]
[0008] According to the present invention, it is possible to propose a configuration of a WXC device that allows the number of converters provided in the WXC device to be appropriately set. [Brief explanation of the drawings]
[0009] [Figure 1] FIG. 1 is a diagram showing the configuration of a WXC device having a single band configuration according to this embodiment. [Figure 2] FIG. 2 is an explanatory diagram showing input and output lines of a wavelength conversion unit having a single band configuration according to the present embodiment. [Figure 3] FIG. 2 is a configuration diagram showing details of a wavelength conversion unit and a controller having a single-band configuration according to the present embodiment. [Figure 4] FIG. 1 is a configuration diagram showing a WXC device with a multi-band configuration according to this embodiment. [Figure 5] FIG. 2 is an explanatory diagram showing input and output lines of a wavelength conversion unit having a multiband configuration according to the present embodiment. [Figure 6] FIG. 2 is a configuration diagram showing details of a wavelength conversion unit and a controller having a multi-band configuration according to the present embodiment. [Figure 7] FIG. 2 is a hardware configuration diagram of a controller according to the present embodiment. DETAILED DESCRIPTION OF THE INVENTION
[0010] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. This embodiment is divided into the following two examples. Common to both embodiments, the WXC device (wavelength cross-connect device) has input / output ports for inputting and outputting optical signals of multiple wavelength bands (multi-bands), and has a WSS for performing wavelength selection and route switching on the optical signals from the input port and transmitting them from the output port. On the other hand, the difference between the two embodiments is the type of WSS used. 1 to 3 uses a WSS (single-band configuration) that can select wavelengths and switch routes for one wavelength band (single band). The letter "s" at the end of the reference numeral of each component in the WXC device 100s indicates a single-band configuration. 4 to 6 uses a WSS (multi-band configuration) that can simultaneously select wavelengths and switch routes for multiple wavelength bands (multi-bands). The letter "m" at the end of the reference numeral of each component in the WXC device 100m indicates a multi-band configuration. The wavelength bands are, for example, three wavelength bands, in order from the shortest wavelength side, the S band of 1460 nm to 1530 nm, the C band of 1530 nm to 1565 nm, and the L band of 1565 nm to 1625 nm. [Example]
[0011] FIG. 1 is a diagram showing the configuration of a WXC device 100s having a single-band configuration. The WXC device 100s is connected to external devices via M input ports (ports Pi1, ..., port PiM) and M output ports (ports Po1, ..., port PoM) by optical fibers. Optical signals in multiple wavelength bands are transmitted and received through the optical fibers connected to each input / output port of the WXC device 100s.
[0012] The WXC device 100s includes a WXC unit (wavelength cross-connect unit) 10s, a wavelength conversion unit 20s, and a controller 30. The controller 30 (details of which are shown in FIG. 3) controls the WXC unit 10s and the wavelength conversion unit 20s. The WXC unit 10s receives an optical signal obtained by multiplexing optical signals of multiple wavelength bands from each input port of the WXC device 100s, demultiplexes the received optical signal into individual wavelength bands, and inputs the demultiplexed optical signals to the wavelength conversion unit 20s. The WXC unit 10s then multiplexes the optical signals of the individual wavelength bands output from the wavelength conversion unit 20s, and outputs the multiplexed optical signals from each output port of the WXC device 100s. In other words, the WXC unit 10s switches the route of optical signals that do not require wavelength conversion, and transmits optical signals that do require wavelength conversion to the wavelength conversion unit 20s. This allows route switching to be performed without degradation of transmission quality due to wavelength conversion. Note that a configuration in which the wavelength conversion unit 20s is separated as a component separate from the WXC unit 10s is also called a trunk type.
[0013] The WXC unit 10s is connected to a demultiplexer 11s, an ingress WSS 12s, an egress WSS 13s, and a multiplexer 14s in this order from the input port side (left side in FIG. 1). The M demultiplexers 11s are connected to the M input ports in a 1:1 ratio. Each demultiplexer 11s demultiplexes a multi-band optical signal (an optical signal obtained by multiplexing an S-band optical signal, a C-band optical signal, and an L-band optical signal) input from each input port into a single-band optical signal (an S-band optical signal, a C-band optical signal, and an L-band optical signal). Each demultiplexer 11s then outputs each demultiplexed optical signal to the downstream ingress WSS 12s for each wavelength band.
[0014] For example, the first demultiplexer 11s receives a first optical signal from the first input port Pi1 and demultiplexes the first optical signal into three optical signals. The first demultiplexer 11s then outputs the demultiplexed S-band optical signal to the S-band ingress WSS 12s, outputs the demultiplexed C-band optical signal to the C-band ingress WSS 12s, and outputs the demultiplexed L-band optical signal to the L-band ingress WSS 12s.
[0015] The ingress WSSs 12s are configured for different wavelength bands, such as S-band WSS, C-band WSS, and L-band WSS, and receive optical signals of the corresponding wavelength bands from the demultiplexer 11s. In other words, the ingress WSSs 12s connected to the input port Pi1 are provided with ones that can switch the direction of the optical signal in the wavelength band input from the input port Pi1. In the example of Figure 1, one demultiplexer 11s is connected to three ingress WSSs 12s, so the total number of ingress WSSs 12s is (3 × M). The egress WSSs 13s are also configured for different wavelength bands, such as S-band WSS, C-band WSS, and L-band WSS, and receive optical signals of the corresponding wavelength bands from the demultiplexer 11s. In other words, since one ingress WSS 12s and one egress WSS 13s are connected, the total number of egress WSSs 13s is (3 × M).
[0016] Between the ingress WSS 12s and egress WSS 13s, WSSs that handle the same wavelength band are directly connected to transmit optical signals that do not require wavelength conversion. For example, an S-band WSS among the ingress WSS 12s is connected to an S-band WSS among the egress WSS 13s that handles the same S-band and does not require wavelength conversion. For optical signals received from each input port of the WXC device 100s that do not require wavelength band conversion, the ingress WSS 12s provided in the WXC unit 10s performs path switching using the ingress WSS 12s instead of inputting the optical signals to the wavelength conversion unit 20s. The ingress WSS 12s then outputs the optical signals from each output port of the WXC device 100s via the egress WSS 13s. As a result, optical signals that do not require wavelength conversion can be transmitted without passing through the wavelength conversion unit 20s, without suffering from degradation in transmission quality, and wavelength collisions can be avoided.
[0017] The ingress WSS 12s is also connected to the wavelength converter 20s. As a result, optical signals that require wavelength conversion are wavelength converted by passing from the ingress WSS 12s through the wavelength converter 20s, thereby avoiding wavelength collisions. Furthermore, the egress WSS 13s is also connected to the wavelength converter 20s. As a result, optical signals that have been wavelength converted by the wavelength converter 20s are routed via the egress WSS 13s together with optical signals that do not require wavelength conversion.
[0018] The M multiplexers 14s are connected to the M output ports in a 1:1 ratio. Each multiplexer 14s multiplexes the single-band optical signals (S-band optical signal, C-band optical signal, and L-band optical signal) input from each output WSS 13s into a multi-band optical signal (an optical signal obtained by multiplexing an S-band optical signal, a C-band optical signal, and an L-band optical signal). Each multiplexer 14s then outputs the multiplexed optical signals from the output port to which it is connected to an external device.
[0019] Fig. 2 is an explanatory diagram showing input / output lines of a wavelength conversion unit 20s having a single band configuration. In the explanation of Fig. 1, for ease of explanation, the number of wavelength bands is set to three (S band, C band, and L band). On the other hand, in Figs. 2 and 3, the number of wavelength bands is generalized to K (B1 band, B2 band, ..., BK band).
[0020] The wavelength converter 20s converts the wavelength of the optical signal input from the WXC unit 10s to an arbitrary wavelength and switches the route to an arbitrary output port according to the optical path setting. The wavelength conversion by the wavelength converter 20s also includes wavelength band conversion (conversion to a wavelength in another wavelength band). For example, the wavelength converter 20s receives optical signals of different wavelength bands (B1, B2, ..., BK) input from the input port Pi1 in FIG. 1 from the ingress WSS 12s of different wavelength bands connected to the input port Pi1 of the WXC unit 10s. Similarly, the wavelength converter 20s receives optical signals of different wavelength bands input from the input port PiM in FIG. 1. Furthermore, the wavelength converter 20s outputs the optical signals for each wavelength band output from the output port Po1 in Fig. 1 toward the outgoing WSS 13s for each wavelength band connected to the output port Po1 of the WXC unit 10s. Similarly, the wavelength converter 20s outputs the optical signals for each wavelength band output from the output port PoM in Fig. 1 toward the outgoing WSS 13s for each wavelength band connected to the output port PoM of the WXC unit 10s.
[0021] FIG. 3 is a configuration diagram showing details of the wavelength conversion unit 20s and the controller 30 having a single-band configuration. The wavelength converter 20s is configured by connecting, in the order of input of the optical signal, an ingress WSS 21s, an ingress multiplexer 22s, a converter 23s, an egress WSS 24s, and an egress multiplexer 25s. The wavelength conversion units 20s are provided for each wavelength band and for each input port for the ingress WSS 21s that can receive optical signals in individual wavelength bands input from the WXC unit 10s. The ingress WSS (ingress wavelength switch) 21s outputs optical signals input from each input port of the WXC device 100s to one of multiple converters 23s. Therefore, the ingress WSS 21s has one input terminal that receives optical signals of different wavelength bands input from the WXC unit 10s, and one or more output terminals for outputting optical signals to the ingress multiplexer 22s directed to unused converters 23s. Note that in Figure 3, some of the connection lines between the components are omitted because showing all of the connection lines would make the drawing too complicated.
[0022] The ingress multiplexer 22s has one or more input terminals that receive optical signals of different wavelength bands input from the ingress WSS 21s, and one output terminal that outputs the result of multiplexing the received one or more optical signals to the converter 23s. Note that the wavelength band (e.g., B1) of the optical signal received by the ingress multiplexer 22s from the input terminal is connected to match the wavelength band before conversion by the converter 23s that receives the optical signal output from the output terminal of the ingress multiplexer 22s (e.g., B1 in the case of a "B1 → B2 converter").
[0023] The converter 23s converts the wavelength band of an optical signal input from each ingress WSS 21s, which handles the optical signal input from each input port, to another wavelength band and outputs the converted optical signal to the egress WSS 24s. Therefore, the converter 23s has one input terminal for receiving the optical signal input from the ingress multiplexer 22s and one output terminal for outputting the result of converting the wavelength band of the received optical signal to another wavelength band to the egress WSS 24s. In other words, the converter 23s is connected to the egress WSS 24s, which can switch the direction of the optical signal in the converted wavelength band. Note that in FIG. 3, the combination of the wavelength band before conversion (here, B1) and the wavelength band after conversion (here, B2) when each converter 23s performs wavelength conversion is indicated within the component, such as "B1 → B2 converter."
[0024] The converter 23s receives the optical signal from the ingress WSS 21s connected to the input port Pi1 and the optical signal from the ingress WSS 21s connected to the input port PiM from the ingress multiplexer 22s and subjects them to wavelength conversion. In other words, one converter 23s is shared by the input ports Pi1 to PiM (M input ports).
[0025] The egress WSS (egress wavelength switch) 24s switches the direction of the optical signal input from the converter 23s toward each output port of the WXC device 100s. To this end, the egress WSS 24s has one input terminal for receiving the optical signal input from the converter 23s and one or more output terminals for outputting the received optical signal to a direction-switched destination according to the optical path setting. The output multiplexer 25s has one or more input terminals for receiving optical signals of different wavelength bands input from the output WSS 24s, and one output terminal for outputting the result of multiplexing the received one or more optical signals to the output WSS 13s of different wavelength bands.
[0026] The number of converters 23s is arbitrary and can be increased or decreased as needed depending on the usage of the converters 23s. The number of input multiplexers 22s, the number of converters 23s, and the number of output WSSs 24s are the same because they are connected one-to-one. Furthermore, for the combinations of "input wavelength band → output wavelength band" handled by the converter 23s, any number can be prepared for each combination of wavelength bands, such as preparing three "B1 → B2 converters" and four "B1 → B3 converters." Furthermore, in a single-band configuration, the number of ingress WSSs 21s is the product of the number of input ports of the WXC device 100s (M in Figure 1) and the number of wavelength bands input from the input ports of the WXC device 100s (K in Figure 1).
[0027] The controller 30 manages the state of each converter 23s, whether it is in use or unused, and controls the ingress WSS 21s to output optical signals to unused converters 23s. To this end, the controller 30 has a state management unit 31, an output setting unit 32, and an expansion instruction unit 33, and manages the WXC units 10s and wavelength conversion units 20s in the WXC device 100s. The controller 30 is connected to each converter 23s in the wavelength conversion units 20s, and the state management unit 31 monitors the usage status (whether it is in use or unused) of each converter 23s. The controller 30 is connected to each WSS in the WXC device 100s. The WSSs are the ingress WSS (second ingress wavelength switch) 12s and egress WSS 13s of the WXC unit 10s, and the ingress WSS 21s and egress WSS 24s of the wavelength conversion unit 20s. The output setting unit 32 sets which wavelength band optical signals input to each WSS are to be distributed (routed) to which output terminal, and which wavelength band is to be assigned to the output terminal.
[0028] Here, the output setting unit 32 refers to the usage status of each converter 23s acquired by the status management unit 31, and when distributing optical signals from the ingress WSS 21s to the subsequent ingress multiplexer 22s and then to the converters 23s, selects the ingress multiplexer 22s directed to an unused converter 23s as the output destination, thereby making it possible to avoid collisions of optical signals within the converters 23s. On the other hand, during the time period when all converters 23s are in use, the output setting unit 32 sets the output destination for the ingress WSS 12s of the WXC unit 10s to be the egress WSS 13s so that the optical signal is not transmitted from the WXC unit 10s to the wavelength conversion unit 20s. In other words, when there is no unused converter 23s, the output setting unit 32 does not input the optical signals received from each input port of the WXC device 100s to the wavelength conversion unit 20s. Instead, the output setting unit 32 controls the optical signals to be output from each output port of the WXC device 100s by switching the path using the ingress WSS 12s provided in the WXC unit 10s.
[0029] In addition, the expansion instruction unit 33 acquires the usage status of each converter 23s from the status management unit 31, and based on the operating rate of the converters 23s calculated from the usage status of each converter 23s, prepares a plan for future expansion or reduction of converters 23s and instructs the operator on the plan. For example, suppose an optical signal transmission service is started with 100 converters 23s, 100 input multiplexers 22s, and 100 output WSSs 24s. After that, a situation occurs where the utilization rate of the 100 converters 23s exceeds a predetermined threshold, such as 95% (95 converters are in use on average at all times). In this case, the expansion instruction unit 33 prepares a plan to add 50 converters 23s so that the total number becomes 150, and instructs the operator about the plan. This instruction may also include an instruction to add 150 inbound multiplexers 22s and 150 outbound WSSs 24s in addition to the addition of converters 23s.
[0030] This allows the administrator to prepare an appropriate number of converters 23s according to the usage status of the converters 23s, thereby preventing the WXC device 100s from becoming excessively large due to the preparation of excessive converters 23s, and also preventing the WXC device 100s from having insufficient performance due to the preparation of too few converters 23s. Furthermore, in the WXC device 100s, the converters 23s can be shared by all input ports. Therefore, compared to a configuration in which a converter 23s is provided exclusively for one input port, the number of converters 23s can be increased or decreased with greater flexibility, and converters can be actively added or removed depending on the communication load. Furthermore, in a single-band WXC device 100s, each WSS in the device uses a WSS that supports one wavelength band, which allows the WXC device 100s to be built at low cost and with a simple and inexpensive WSS. [Example]
[0031] FIG. 4 is a diagram showing the configuration of a WXC device 100m having a multi-band configuration. The WXC device 100m includes a WXC unit 10m, a wavelength conversion unit 20m, and a controller 30. The controller 30 controls the WXC unit 10m and the wavelength conversion unit 20m, similarly to the first embodiment. Like the single-band WXC device 100s, the WXC device 100m is connected to external devices via optical fibers via M input ports (ports Pi1, ..., port PiM) and M input ports (ports Po1, ..., port PoM). Optical signals in multiple wavelength bands are transmitted and received through the optical fibers connected to each input / output port of the WXC device 100m. The WXC unit 10m receives optical signals that are multiplexed from optical signals of multiple wavelength bands from each input port of the WXC device 100m, inputs the received optical signals to the wavelength conversion unit 20m, and outputs the optical signals output from the wavelength conversion unit 20m from each output port of the WXC device 100m.
[0032] The WXC unit 10m is connected to an ingress WSS 12m and an egress WSS 13m, starting from the input port side (left side in Figure 4). In a multi-band configuration, the demultiplexer 11s and multiplexer 14s used in the single-band configuration are no longer necessary, allowing the WXC unit 10m to be slimmed down. The ingress WSS 12m can accept optical signals in each wavelength band (S band, C band, L band) from the same input port (for example, port Pi1). There is a one-to-one correspondence between the ingress WSS 12m and the input port, so the total number of ingress WSSs 12m is M. Similar to the ingress WSS 12s having a single-band configuration, the ingress WSS 12m having a multi-band configuration has an output terminal for transmitting optical signals that do not require wavelength conversion to the downstream egress WSS 13m, and an output terminal for transmitting optical signals that require wavelength conversion to the wavelength conversion unit 20m.
[0033] 5 is an explanatory diagram showing input and output lines of a wavelength conversion unit 20m having a multi-band configuration. The explanation will be given assuming that the number of wavelength bands is K (B1 band, B2 band, . . . BK band). The wavelength conversion unit 20m of the multi-band configuration, like the wavelength conversion unit 20s of the single-band configuration, converts the wavelength of the optical signal input from the WXC unit 10m to an arbitrary wavelength and switches the route to an arbitrary output port according to the optical path setting. Meanwhile, in the single-band configuration of Fig. 2, the input and output terminals of the wavelength conversion unit 20s are separated by wavelength band, whereas in the multi-band configuration of Fig. 5, the input and output terminals of the wavelength conversion unit 20m are separated by port of the WXC device 100m, allowing signals of multiple wavelength bands to be transmitted through a single port.
[0034] FIG. 6 is a configuration diagram showing details of the wavelength conversion unit 20m and the controller 30 having a multi-band configuration. The controller 30 in the multi-band configuration has a status management unit 31, an output setting unit 32, and an expansion instruction unit 33, similar to the controller in the single-band configuration. The state management unit 31 monitors the usage state (whether the converter 23m is in use or unused) of each converter 23m. The output setting unit 32 refers to the usage status of each converter 23m acquired by the status management unit 31, and when distributing an optical signal from the input WSS 21m to the subsequent input multiplexer 22m → converter 23m, selects the input multiplexer 22m heading to an unused converter 23m as the output destination. The expansion instruction unit 33 acquires the usage status of each converter 23m from the status management unit 31, and based on the operating rate of the converter 23m calculated from the usage status of each converter 23m, prepares a plan for future expansion or reduction of converters 23m and instructs the operator on the plan.
[0035] The following will list (1) to (5) the differences between the single-band configuration in FIG. 3 and the multi-band configuration in FIG. (1) Differences in the ingress WSS 21m: As the number of input terminals in the wavelength conversion unit 20m has been reduced from (number of input ports) × (number of wavelength bands) in Figure 2 to (number of input ports) in Figure 5, the number of ingress WSSs 21m has also been reduced to the same number as the number of input ports (M). In other words, the wavelength conversion unit 20m has an ingress WSS 21m for each input port that can input optical signals in multiple wavelength bands input from the WXC unit 10m. Note that while the ingress WSS 21s in Figure 3 was a low-performance WSS compatible with a single band, the ingress WSS 21m in Figure 6 requires a high-performance WSS compatible with multiple bands.
[0036] (2) Differences in the ingress multiplexer 22m: The number of ingress multiplexers 22m is the same as the number of converters 23m connected 1:1, whether in the single-band configuration of Fig. 3 or the multi-band configuration of Fig. 6. In addition, since the ingress WSS 21m in Fig. 6 is reduced, the wiring between the ingress WSS 21m and the ingress multiplexer 22m becomes simpler.
[0037] (3) Differences in the converters 23m: There are no differences. Whether in the single-band configuration of Fig. 3 or the multi-band configuration of Fig. 6, the number of converters 23m can be flexibly changed depending on the usage situation.
[0038] (4) Differences in the egress WSS 24m: The egress WSS 24s in Figure 3 was a low-function WSS that supported a single band, but the egress WSS 24m in Figure 6 requires a high-function WSS that supports multiple bands. However, if the egress WSS 24m supports multiple bands and multiple converters 23m are connected to one egress WSS 24m within a range where the converted wavelength bands do not overlap (n:1 connection), the number of egress WSSs 24m can be reduced.
[0039] (5) Differences in the output multiplexer 25m: As the number of output terminals of the wavelength conversion unit 20m is reduced from (number of output ports) × (number of wavelength bands) in Fig. 2 to (number of output ports) in Fig. 5, the number of output multiplexers 25m is also reduced to the same number as the number of output ports (M). The fact that the output WSS 24m and the output multiplexer 25m are connected by output port is the same in both the single-band configuration in Fig. 3 and the multi-band configuration in Fig. 6.
[0040] As described above, by using a highly functional WSS that supports multiple bands for the WXC unit 10m and the wavelength conversion unit 20m, the number of WSSs can be reduced, the WXC device 100m can be constructed in a space-saving manner, and can be operated with reduced power consumption.
[0041] FIG. 7 is a diagram showing the hardware configuration of the controller 30. As shown in FIG. The controller 30 is configured as a computer 900 having a CPU 901 , a RAM 902 , a ROM 903 , a HDD 904 , a communication I / F 905 , an input / output I / F 906 , and a media I / F 907 . The communication I / F 905 is connected to an external communication device 915. The input / output I / F 906 is connected to an input / output device 916. The media I / F 907 reads and writes data from a recording medium 917. Furthermore, the CPU 901 controls each unit by executing a program (also called an application or an app for short) loaded into the RAM 902. This program can also be distributed via a communication line or recorded on a recording medium 917 such as a CD-ROM and distributed. Alternatively, the controller 30 may be implemented as a field programmable gate array (FPGA) or an application specific integrated circuit (ASIC) that implements program logic, instead of the CPU 901 of the computer 900 executing the program. Furthermore, the controller 30 may be configured as a housing separate from the WXC devices 100s and 100m, and one controller 30 may manage multiple WXC devices 100s and 100m.
[0042] [effect] The present invention provides a WXC device 100s having a wavelength conversion unit 20s and a controller 30, The wavelength converting unit 20s is an input WSS 21s that outputs optical signals input from each input port of the WXC device 100s to one of a plurality of converters 23s; a converter 23s that converts the wavelength band of an optical signal input from each input WSS 21s that handles an optical signal input from each input port into another wavelength band and outputs the converted optical signal to an output WSS 24s; and an output WSS 24s that switches the direction of the optical signal input from the converter 23s toward each output port of the WXC device 100s. The controller 30 manages the state of each converter 23s, whether it is in use or unused, and controls the ingress WSS 21s so as to output an optical signal to the unused converter 23s.
[0043] This allows for a trunk-type configuration in which processing units for wavelength conversion of optical signals input from each input port are concentrated in the wavelength conversion unit 20s, making it possible to flexibly increase or decrease the number of converters 23s according to demand. Also, converters 23s are not provided for each input port, but are shared by multiple input ports. Furthermore, by controlling the ingress WSS 21s to output optical signals to unused converters 23s, the availability of the converters 23s can be improved and the number of wavelength converters 20s can be reduced. In this way, by reducing the number of wavelength converters 20s to the required number, the cost of the WXC device 100s can be reduced. As described above, the present invention proposes a configuration of a WXC device that allows the number of converters provided in the WXC device to be appropriately set.
[0044] The present invention provides a WXC device 100s further comprising a WXC unit 10s, The WXC unit 10s receives an optical signal obtained by multiplexing optical signals of multiple wavelength bands from each input port of the WXC device 100s, demultiplexes the received optical signal into individual wavelength bands, inputs the demultiplexed optical signals into the wavelength conversion unit 20s, multiplexes the optical signals of the individual wavelength bands output from the wavelength conversion unit 20s, and outputs the multiplexed optical signal from each output port of the WXC device 100s. The wavelength conversion unit 20s is characterized by including ingress WSSs 21s for each wavelength band and for each input port, which are capable of receiving optical signals in individual wavelength bands input from the WXC unit 10s.
[0045] This allows the cost of the WXC device 100s to be reduced by using a low-cost ingress WSS 21s that supports a single band in the wavelength conversion unit 20s.
[0046] The present invention provides a WXC device 100m further comprising a WXC unit 10m, The WXC unit 10m receives an optical signal obtained by multiplexing optical signals in a plurality of wavelength bands from each input port of the WXC device 100m, inputs the received optical signal to the wavelength conversion unit 20m, and outputs the optical signal output from the wavelength conversion unit 20m from each output port of the WXC device 100m. The wavelength conversion unit 20m is characterized by including, for each input port, an ingress WSS 21m capable of receiving optical signals in a plurality of wavelength bands input from the WXC unit 10m.
[0047] As a result, by using a highly functional ingress WSS 21m that supports multiple bands in the wavelength conversion section 20m, the number of ingress WSS 21m and the wiring layout can be simplified, and the size of the WXC device 100m can be reduced.
[0048] The present invention is characterized in that, for optical signals that do not require wavelength band conversion among the optical signals received by the WXC unit 10s from each input port of the WXC device 100s, instead of inputting them to the wavelength conversion unit 20s, the WXC unit 10s outputs the optical signals from each output port of the WXC device 100s by performing route switching using the ingress WSS 12s provided within the WXC unit 10s.
[0049] This allows optical signals that do not require wavelength band conversion to be transmitted at high speed by bypassing the wavelength conversion unit 20s.
[0050] The present invention is characterized in that when there is no unused converter 23s, the controller 30 controls the optical signals received from each input port of the WXC device 100s to be output from each output port of the WXC device 100s by switching the route using the ingress WSS 12s provided in the WXC unit 10s, instead of inputting them to the wavelength conversion unit 20s.
[0051] As a result, when the converter 23s is short of capacity, the optical signal can be processed without loss by bypassing the wavelength conversion unit 20s. [Explanation of symbols]
[0052] 100s, 100m WXC equipment (wavelength cross connect equipment) 10s, 10m WXC section (wavelength cross connect section) 11s,11m splitter 12s, 12m ingress WSS (second ingress wavelength switch) 13s,13m Exit WSS 14s,14m multiplexer 20s, 20m wavelength conversion unit 21s, 21m Ingress WSS (ingress wavelength switch) 22s,22m Input multiplexer 23s, 23m converter 24s, 24m egress WSS (egress wavelength switch) 25s,25m Output multiplexer 30 Controllers 31 Status Management Unit 32 Output setting section 33 Expansion Instruction Department
Claims
1. An optical transmission system including a wavelength cross-connect device having a wavelength conversion unit and a controller, The wavelength converting portion is an input wavelength switch that outputs optical signals obtained by demultiplexing optical signals input from each input port of the wavelength cross-connect device into individual wavelength bands to any one of a plurality of wavelength converters; a wavelength converter that converts a wavelength band of an optical signal input from each of the ingress wavelength switches that handles the optical signal input from each input port into another wavelength band, and outputs the converted optical signal to an egress wavelength switch; an output wavelength switch that switches the direction of the optical signal input from the wavelength converter toward each output port of the wavelength cross-connect device, The controller manages whether each of the wavelength converters is in use or unused, and controls the ingress wavelength switch so as to output an optical signal to the wavelength converter that is unused. Optical transmission system.
2. the wavelength cross-connect device further includes a wavelength cross-connect unit, the wavelength cross-connect unit receives an optical signal obtained by multiplexing optical signals of a plurality of wavelength bands from each input port of the wavelength cross-connect device, demultiplexes the received optical signal into individual wavelength bands, inputs the demultiplexed optical signals into the wavelength conversion unit, multiplexes the optical signals of the individual wavelength bands output from the wavelength conversion unit, and outputs the multiplexed optical signal from each output port of the wavelength cross-connect device; The wavelength conversion unit is characterized in that the ingress wavelength switch capable of inputting optical signals in individual wavelength bands input from the wavelength cross-connect unit is provided for each wavelength band and for each input port.
2. The optical transmission system according to claim 1.
3. An optical transmission system including a wavelength cross-connect device having a wavelength conversion unit and a controller, The wavelength converting portion is an input wavelength switch that outputs an optical signal, which is input from each input port of the wavelength cross-connect device and is obtained by multiplexing optical signals in a plurality of wavelength bands, to one of a plurality of wavelength converters; a wavelength converter that converts a wavelength band of an optical signal input from each of the ingress wavelength switches that handles the optical signal input from each input port into another wavelength band, and outputs the converted optical signal to an egress wavelength switch; an output wavelength switch that switches the direction of the optical signal input from the wavelength converter toward each output port of the wavelength cross-connect device, The controller manages whether each of the wavelength converters is in use or unused, and controls the ingress wavelength switch so as to output an optical signal to the wavelength converter that is unused. Optical transmission system.
4. the wavelength cross-connect device further includes a wavelength cross-connect unit, the wavelength cross-connect unit receives an optical signal obtained by multiplexing optical signals in a plurality of wavelength bands from each input port of the wavelength cross-connect device, inputs the received optical signal to the wavelength conversion unit, and outputs the optical signal output from the wavelength conversion unit from each output port of the wavelength cross-connect device; The wavelength conversion unit is characterized in that the input wavelength switch capable of inputting optical signals in a plurality of wavelength bands input from the wavelength cross-connect unit is provided for each input port.
4. The optical transmission system according to claim 3.
5. The wavelength cross connect unit is characterized in that, for optical signals that do not require wavelength band conversion among the optical signals received from each input port of the wavelength cross connect device, the optical signals are output from each output port of the wavelength cross connect device by switching the direction using a second input wavelength switch provided in the wavelength cross connect unit instead of inputting the optical signals to the wavelength converter.
5. The optical transmission system according to claim 2 or 4.
6. When there is no unused wavelength converter, the controller controls the optical signals received from the input ports of the wavelength cross connect device to be output from the output ports of the wavelength cross connect device by switching the direction of the optical signals using the second input wavelength switch provided in the wavelength cross connect unit, instead of inputting the optical signals to the wavelength conversion unit.
6. The optical transmission system according to claim 5.
7. An optical transmission method executed by an optical transmission system having a wavelength cross-connect device having a wavelength conversion unit and a controller, The wavelength converting portion is an input wavelength switch that outputs optical signals obtained by demultiplexing optical signals input from each input port of the wavelength cross-connect device into individual wavelength bands to any one of a plurality of wavelength converters; a wavelength converter that converts a wavelength band of an optical signal input from each of the ingress wavelength switches that handles the optical signal input from each input port into another wavelength band, and outputs the converted optical signal to an egress wavelength switch; an output wavelength switch that switches the direction of the optical signal input from the wavelength converter toward each output port of the wavelength cross-connect device, The controller manages whether each of the wavelength converters is in use or unused, and controls the ingress wavelength switch so as to output an optical signal to the wavelength converter that is unused. Optical transmission method.
8. An optical transmission method executed by an optical transmission system having a wavelength cross-connect device having a wavelength conversion unit and a controller, The wavelength converting portion is an input wavelength switch that outputs an optical signal, which is input from each input port of the wavelength cross-connect device and is obtained by multiplexing optical signals in a plurality of wavelength bands, to one of a plurality of wavelength converters; a wavelength converter that converts a wavelength band of an optical signal input from each of the ingress wavelength switches that handles the optical signal input from each input port into another wavelength band, and outputs the converted optical signal to an egress wavelength switch; an output wavelength switch that switches the direction of the optical signal input from the wavelength converter toward each output port of the wavelength cross-connect device, The controller manages whether each of the wavelength converters is in use or unused, and controls the ingress wavelength switch so as to output an optical signal to the wavelength converter that is unused. Optical transmission method.
9. A wavelength cross-connect device having a wavelength conversion unit, The wavelength converting portion is an input wavelength switch that outputs optical signals obtained by demultiplexing optical signals input from each input port of the wavelength cross-connect device into individual wavelength bands to any one of a plurality of wavelength converters; a wavelength converter that converts a wavelength band of an optical signal input from each of the ingress wavelength switches that handles the optical signal input from each input port into another wavelength band, and outputs the converted optical signal to an egress wavelength switch; an output wavelength switch that switches the direction of the optical signal input from the wavelength converter toward each output port of the wavelength cross-connect device, The ingress wavelength switch receives control from a controller that manages whether each of the wavelength converters is in use or unused, to output an optical signal to the unused wavelength converter, and outputs the optical signal to the unused wavelength converter. Wavelength cross-connect device.
10. A wavelength cross-connect device having a wavelength conversion unit, The wavelength converting portion is an input wavelength switch that outputs an optical signal, which is input from each input port of the wavelength cross-connect device and is obtained by multiplexing optical signals in a plurality of wavelength bands, to one of a plurality of wavelength converters; a wavelength converter that converts a wavelength band of an optical signal input from each of the ingress wavelength switches that handles the optical signal input from each input port into another wavelength band, and outputs the converted optical signal to an egress wavelength switch; an output wavelength switch that switches the direction of the optical signal input from the wavelength converter toward each output port of the wavelength cross-connect device, The ingress wavelength switch receives control from a controller that manages whether each of the wavelength converters is in use or unused, to output an optical signal to the unused wavelength converter, and outputs the optical signal to the unused wavelength converter. Wavelength cross-connect device.