Optical transmission device and optical transmission method

Abstract

A WSS (230A) of an optical transmission device (200A): outputs, with respect to an input signal requiring wavelength conversion, a wavelength component after wavelength conversion, as a transmission signal, from a cross connect (240A) to an output port; and outputs a wavelength component before the wavelength conversion, as an extraction signal, to a monitoring measurement instrument (290). With respect to an input signal that does not require wavelength conversion, the WSS (230A): outputs a wavelength component before wavelength conversion, as a transmission signal, to the output port; and outputs a wavelength component after wavelength conversion, as an extraction signal, to the monitoring measurement instrument (290).

Description

Optical transmission device and optical transmission method The present invention relates to an optical transmission device and an optical transmission method. Optical transmission equipment that supports wavelength cross-connect (WXC) is becoming widespread. The WXC function outputs wavelength multiplexed signal light transmitted from an input path to any output path. Furthermore, in a network that applies multiband transmission, a wavelength conversion function that converts the wavelength of an optical signal to another wavelength is added to the optical transmission device. The wavelength conversion function is expected to suppress the deterioration of transmission quality due to interband Raman scattering (Non-Patent Document 1) and increase the amount of traffic that can be accommodated (Non-Patent Document 2). 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)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) In an optical transmission system that connects a sending node and a receiving node with a relatively long-distance optical fiber cable and transmits an optical signal, it is expected that the optical signal will be significantly attenuated along the transmission path, and the transmission quality will deteriorate. Therefore, in order to ensure that the optical signal transmitted from the sending node reaches the receiving node, it is generally necessary to place one or more relay nodes along the transmission path to amplify the attenuated optical signal and correct bit errors that occur along the transmission path. Each relay node in an optical transmission system usually has an electrical termination function. That is, it converts the received optical signal into an electrical signal and relays the converted electrical signal information. When processing the electrical signal information, it can also obtain (monitor) the transmission quality data (Pre-FEC BER, dispersion compensation amount, polarization mode dispersion amount, polarization dependent loss) at the relay node. When a fault occurs in an optical transmission system, it is necessary to identify the location of the fault. To do this, first, the entire length of the long-distance transmission line is divided into multiple sections at each relay node, and the presence or absence of a fault is identified for each section. If each relay node is equipped with an electrical termination function, it is possible to obtain transmission quality data for each relay node. Therefore, by comparing the transmission quality data of each relay node, it is possible to determine whether or not a fault has occurred in each section. However, for relay nodes that do not implement electrical termination processing, it is not possible to obtain transmission quality data at those points. As a result, each section where it is possible to isolate whether or not there is a fault may contain many optical transmission devices, and the length of the optical fiber cable per section may become very long, making it difficult to identify the location of the fault. Therefore, we consider a method of generating a wavelength-converted wavelength signal from a wavelength signal before wavelength conversion by passing one optical signal received by a relay node through a wavelength converter with an AO-WC (All Optical Wavelength Conversion) function. In this case, the wavelength signal before wavelength conversion is not used for relaying, so it can be converted into an electrical signal and used to obtain transmission quality data. Therefore, when a fault occurs on an optical network, it becomes easy to identify the location of the fault. Even when no fault occurs, information that is useful for predicting failures on the optical network can be obtained. In addition, the wavelength signal after wavelength conversion is relayed to the downstream side without the need for electrical termination processing, so there is no impact on signal delay or deterioration of transmission quality. However, not only optical signals that require wavelength conversion by passing through a wavelength converter are input to a relay node, but also optical signals that do not require wavelength conversion within the relay node. In this case, in a system in which a relay node has a transmission path that passes through a wavelength conversion device and a detour path that does not pass through the wavelength conversion device, optical signals that do not pass through the wavelength conversion device will bypass the wavelength conversion device by passing through the detour path, and will be excluded from being monitored. Therefore, a main object of the present invention is to monitor optical signals passing through optical transmission equipment regardless of whether wavelength band conversion is required. In order to solve the above problems, an optical transmission device according to the present invention has the following features. The present invention provides an optical transmission device that performs optical relay processing to output an input signal, which is an input optical signal, as a transmission signal to another device, the optical transmission device includes a wavelength conversion unit, a first wavelength selective switch (WSS), a cross connect, and a monitoring measuring instrument; The wavelength conversion unit converts the wavelength of the input signal regardless of whether or not wavelength conversion of the input signal to the optical transmission device is required, thereby outputting output light including both wavelength components before and after wavelength conversion to the first WSS; The first WSS is For the input signal requiring wavelength conversion, a wavelength component of the output light after wavelength conversion is output as the transmission signal from the cross connect to an output port, and a wavelength component of the output light before wavelength conversion is output as an extraction signal to the monitoring measuring instrument; For the input signal that does not require wavelength conversion, a wavelength component of the output light before wavelength conversion is output as the transmission signal from the cross connect to an output port, and a wavelength component of the output light after wavelength conversion is output as the extraction signal to the monitoring measuring instrument; The monitoring measuring instrument detects transmission quality data of the extracted signal output from the first WSS by electrically terminating the extracted signal. According to the present invention, an optical signal passing through an optical transmission device can be subject to monitoring regardless of whether or not wavelength band conversion is required. FIG. 1 is a configuration diagram of an optical transmission system according to the present embodiment. FIG. 2 is a configuration diagram of an all-optical wavelength conversion unit included in the optical transmission system of FIG. 1 according to the present embodiment. FIG. 3 is a flowchart showing an example of a processing procedure when detecting transmission quality data of a signal requiring wavelength conversion in the optical transmission management method by the optical transmission system according to the present embodiment. FIG. 4 is a flowchart showing an example of a processing procedure when detecting transmission quality data of a signal not requiring wavelength conversion in the optical transmission management method by the optical transmission system according to the present embodiment. FIG. 5 is a graph showing a wavelength distribution when detecting transmission quality data of a signal requiring wavelength conversion using a detector for each wavelength according to the present embodiment. FIG. 6 is a graph showing a wavelength distribution when using a single detector equipped with a wavelength filter instead of the detector for each wavelength in the state of FIG. 5 according to the present embodiment. FIG. 7 is a graph showing a wavelength distribution when using a single detector equipped with a wavelength filter instead of the detector for each wavelength in the state of FIG. 6 according to the present embodiment. FIG. 8 is a graph showing a wavelength distribution when an optical signal requiring wavelength conversion and an unnecessary optical signal according to the present embodiment are input to the same wavelength converter. FIG. 1 is a configuration diagram of an optical transmission device showing a first example of the optical transmission device of FIG. 1 according to the present embodiment. 1 according to the present embodiment. FIG. 2 is a configuration diagram of an optical transmission device showing a second example of the optical transmission device of FIG. 1 according to the present embodiment. FIG. 3 is a configuration diagram of an optical transmission device showing a third example of the optical transmission device of FIG. 1 according to the present embodiment. FIG. 4 is a configuration diagram of an optical transmission device showing a fourth example of the optical transmission device of FIG. 1 according to the present embodiment. FIG. 5 is a configuration diagram of an optical transmission device showing a fifth example of the optical transmission device of FIG. 1 according to the present embodiment. Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a diagram showing the configuration of an optical transmission system 100. The optical transmission system 100 includes five optical transmission devices 51 to 55 and a network controller 20. The five optical transmission devices 51 to 55 are installed, for example, in a row at locations spaced apart from each other by a certain distance. Each of the optical transmission devices 51 to 55 shown in FIG. 1 has a function of transmitting a WDM (Wavelength Division Multiplexing) optical signal in which optical signals of multiple wavelengths are multiplexed. The five optical transmission devices 51 to 55 are connected in series with one another via one or more optical fiber cables 15 used as a transmission path for WDM optical signals. The optical transmission devices 51 and 55, which are located at the ends of the network and function as a transmitting node or a receiving node, each have a plurality of TPDs (Transponders) 11a to 11n mounted thereon for processing WDM optical signals. The network controller 20 manages the entire optical communication network that is composed of the optical transmission devices 51 to 55 and the optical fiber cable 15. For example, when some kind of failure occurs on the optical communication network, the network controller 20 can generate information that is useful for identifying the location of the failure. For example, when transmitting data from optical transmission device 51 at one end of this communication network to optical transmission device 55 at the other end, optical transmission device 51 serves as a transmitting node and optical transmission device 55 serves as a receiving node. In addition, optical transmission devices 52 to 54 between these transmitting and receiving nodes are each used as relay nodes. The optical transmission device 51 at the sending node converts data to be transmitted from an electrical signal to an optical signal of a predetermined wavelength within each of the TPDs 11a to 11n, and transmits a WDM optical signal in which multiple wavelengths are multiplexed to the optical fiber cable 15. The optical transmission device 55 at the receiving node receives the WDM optical signal from the optical fiber cable 15. The optical transmission device 55 separates the received WDM optical signal into wavelengths, converts the optical signal to an electrical signal in each of the TPDs 11a to 11n, and acquires the received data by processing the electrical signal. The optical transmission system 100 includes an all-optical wavelength conversion unit 13A that implements the function of an AO-WC inside an optical transmission device 53 used as one relay node. In addition, a plurality of TPDs 11a to 11n that are compatible with WDM optical signals are implemented in the optical transmission device 53. The all-optical wavelength conversion unit 13A in the optical transmission device 53 handles the following optical signals, as will be described later with reference to FIG. The input signal (input optical signal Oin in FIG. 6) is an optical signal input to the all-optical wavelength conversion unit 13A, and has components in wavelength bands B11 to B1n. The transmission signal (outgoing optical signal Oo2 in FIG. 6) is an optical signal output from the all-optical wavelength converter 13A to the optical transmission device 54 on the downstream side. The extracted signals (emitted light Oo11 to Oo1n in FIG. 6) are optical signals that are output from the all-optical wavelength conversion unit 13A to the detectors 11Aa to 11An and whose transmission quality data is detected (monitored). That is, the optical transmission device 53 performs an optical relay process of outputting an input signal, which is an input optical signal, to another device as a transmission signal. The all-optical wavelength conversion unit 13A performs wavelength conversion processing on the WDM optical signal input to the optical transmission device 53 from the upstream optical fiber cable 15 while it is still an optical signal, generates a WDM optical signal with a different wavelength from the input, and sends it to the downstream optical fiber cable 15. Furthermore, the all-optical wavelength conversion unit 13 A can extract unnecessary optical components separated from the WDM optical main signal relayed by the optical transmission device 53 , and input the extracted components to the detectors 11 Aa to 11 An in the optical transmission device 53 . Each of the detectors 11Aa to 11An has the function of electrical termination processing like the TPDs 11a to 11n, but does not have the function of transmitting optical signals. That is, each of the detectors 11Aa to 11An has the function of converting an input optical signal into an electrical signal and the function of processing this electrical signal to detect transmission quality data. The transmission quality data includes, for example, pre-FEC (Forward Error Correction) BER (Bit Error Rate), dispersion compensation amount, polarization mode dispersion amount, and polarization dependent loss. That is, the optical transmission device 53 does not perform electrical termination processing on the WDM optical main signal to be relayed, and relays the signal as it is to send it to the downstream optical fiber cable 15, thereby preventing an increase in delay due to relay processing. Also, since there is no need to use an optical splitter to extract the optical signal input to the detectors 11Aa to 11An, a decrease in the optical intensity of the WDM optical main signal can be suppressed. In addition, the all-optical wavelength conversion unit 13A extracts unnecessary optical components separated from the WDM optical main signal to be relayed as an extracted signal and inputs it to detectors 11Aa to 11An in the optical transmission device 53, so that the detectors 11Aa to 11An can detect transmission quality data at the node positions of the optical transmission device 53. Therefore, the network controller 20 can obtain the transmission quality data of relay nodes such as the optical transmission device 53 that does not perform electrical termination processing. For example, when a fault occurs, the network controller 20 can determine whether or not a fault has occurred for each section based on the transmission quality data at the position of each relay node. Furthermore, the optical transmission device 53 can also switch the wavelength bands of the transmission signal and the extraction signal depending on whether or not the signal requires wavelength conversion. For signals requiring wavelength conversion, the wavelength bands are B21 to B2n (wavelength bands after wavelength conversion) of the transmission signals, and the wavelength bands are B11 to B1n (wavelength bands before wavelength conversion) of the extracted signals. For signals that do not require wavelength conversion, the wavelength bands are B11 to B1n (wavelength bands before wavelength conversion) for the transmission signals, and B21 to B2n (wavelength bands after wavelength conversion) for the extraction signals. This allows the optical transmission device 53 to obtain transmission quality data even when wavelength conversion is not performed. Fig. 2 is a configuration diagram of the all-optical wavelength conversion unit 13A included in the optical transmission system 100 in Fig. 1. The all-optical wavelength conversion unit 13A includes a pumping light source 14, an optical fiber 15A, an optical multiplexer 16, and a nonlinear optical medium 17. The pumping light source 14 generates pumping light Oe with a predetermined wavelength λe. The pumping light Oe generated by the pumping light source 14 passes through an optical fiber 15A and enters the optical multiplexer 16. The wavelength λe of the pumping light Oe is different from (does not overlap with) each of the wavelength bands B1 to Bn included in the WDM input optical signal Oin. Furthermore, the optical intensity of the pumping light Oe is sufficiently greater than that of the WDM input optical signal Oin. The optical multiplexer 16 generates light by multiplexing the WDM input optical signal Oin input from the optical fiber cable 15 and the pumping light Oe input from the optical fiber 15 A, and sends the light to the input end of the nonlinear optical medium 17 . The nonlinear optical medium 17 has nonlinear optical characteristics and generates an optical signal having a wavelength different from that of the incident light. The nonlinear optical medium 17 is configured as, for example, any one of a highly nonlinear fiber (HNLF), a periodically poled lithium niobate (PPLN), and a semiconductor optical amplifier (SOA). Then, output light Oout is emitted from the output end of the nonlinear optical medium 17. The output light Oout includes both the wavelength band of the input optical signal Oin before wavelength conversion and the wavelength band after wavelength conversion from the input optical signal Oin (described later in graph 303 of FIG. 6 ). FIG. 3 is a flowchart showing an example of a processing procedure for detecting transmission quality data of a signal requiring wavelength conversion in the optical transmission management method by the optical transmission system 100. FIG. 4 is a flowchart showing an example of a processing procedure of the optical transmission management method by the optical transmission system 100 when detecting transmission quality data of a signal that does not require wavelength conversion. Step S13 in Fig. 3 is replaced by step S13B in Fig. 4, and step S14 in Fig. 3 is replaced by step S14B in Fig. 4. The processing procedures in Fig. 3 and Fig. 4 can be used to manage an optical transmission system 100 as shown in Fig. 12, for example. In this optical transmission system 100, at a node position of an optical transmission device 53 that relays communications, the optical transmission device 53 receives an input optical signal Oin from the upstream optical fiber cable 15 in step S11, and the all-optical wavelength converter 13A performs wavelength conversion of the input optical signal Oin in step S12. First, if the input optical signal Oin is a signal that requires wavelength conversion, the optical demultiplexer (WSS 230A in FIG. 11, hereinafter referred to as the "optical demultiplexer") in the all-optical wavelength conversion unit 13A sends out the wavelength-converted outgoing optical signal Oo2 (transmission signal) to the downstream optical fiber cable 15 as a relay output from the cross connect 240A in FIG. 11 (step S13 in FIG. 3). Then, the optical demultiplexer extracts the outgoing light Oo1 having the same wavelength as before the wavelength conversion, i.e., the unnecessary light not used for relaying communications, as an extracted signal in step S14. On the other hand, if the input optical signal Oin does not require wavelength conversion, the optical demultiplexer in the all-optical wavelength conversion unit 13A outputs an optical signal having the same wavelength as before the wavelength conversion as a relay output (step S13B in FIG. 4).Then, the optical demultiplexer extracts the unnecessary optical signal after the wavelength conversion as an extraction signal in step S14B. A detector (monitoring measuring instrument 290 in FIG. 11, hereinafter referred to as "detector") in optical transmission device 53 receives the extracted signal of the unwanted light extracted by the optical demultiplexer in step S15 and converts it into an electrical signal. The detector may be a device equivalent to the receiving section of the TPDs 11a to 11n, a spectrum analyzer, a polarization monitor, a power meter, etc. The receiving section of the TPDs 11a to 11n converts unwanted light into an electrical signal and processes it to obtain transmission quality data in step S16. In the case of a spectrum analyzer, the signal-to-noise ratio is obtained. In the case of a polarization monitor, the polarization state of the optical signal is obtained, and in the case of a power meter, the optical intensity is obtained. The optical transmission device 53 associates the transmission quality data detected by the internal detector with the relay node position and notifies the network controller 20 in step S17. Therefore, by performing the relay processing of FIG. 3, the network controller 20 can obtain transmission quality data even for relay nodes that omit electrical termination processing of transmitted optical signals. FIG. 5 is a diagram showing the hardware configuration of the optical transmission device 53. The optical transmission device 53 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 (optical transmission program) loaded into the RAM 902. This program (also called an application, or an app for short) can be distributed via a communication line or can be recorded on a recording medium 917 such as a CD-ROM and distributed. Hereinafter, the wavelength distribution of the optical signal processed by the optical transmission device 53 in FIG. 1 will be described with reference to FIGS. 6 is a graph showing wavelength distribution when the transmission quality data of a signal requiring wavelength conversion is detected using the detectors 11Aa to 11An for each wavelength. The horizontal axis of the graph represents wavelength, and the vertical axis represents optical intensity. A graph 301 shows that an input signal (input optical signal Oin) input to an optical transmission device 53 from an upstream optical fiber cable 15 contains multiple components of multiple wavelength bands B11 to B1n. A graph 302 shows that the pump light Oe generated by the pump light source 14 contains only a component of a single wavelength λe. Also, the optical intensity of the pump light Oe is sufficiently greater than that of the input optical signal Oin. The all-optical wavelength conversion unit 13A converts the wavelength of the input signal to the optical transmission device 53 regardless of whether or not wavelength conversion of the input signal is required, and outputs output light Oout containing both wavelength components before and after the wavelength conversion to the optical splitter (WSS230A). Graph 303 shows that the optical components of the wavelength bands B11 to B1n, the wavelength λe, and the wavelength bands B21 to B2n are included as output light Oout outputted from the nonlinear optical medium 17 of the all-optical wavelength conversion unit 13A. The wavelengths of the output light Oout are generated by the wavelengths included in the input optical signal Oin, the wavelength λe of the pump light Oe, and the nonlinear optical characteristics of the nonlinear optical medium 17. The optical components in the wavelength bands B21 to B2n are optical components generated by wavelength conversion of the input optical signal Oin accompanying passage through the nonlinear optical medium 17. Moreover, the optical intensity of the components in the wavelength bands B21 to B2n contained in the output light Oout is equivalent to that of the input optical signal Oin. In other words, the wavelength conversion can be performed without attenuating the optical intensity. In addition, the optical intensity of the components of the wavelength bands B11 to B1n included in the output light Oout is equivalent to that of the input optical signal Oin. In other words, optical signals other than the main signal can be extracted from the output of the nonlinear optical medium 17 with sufficiently large optical intensity in the same wavelength bands B11 to B1n as before the wavelength conversion. Graph 304 shows the outgoing optical signal Oo2. By the demultiplexing in the optical splitter, an outgoing optical signal Oo2 containing optical components in the wavelength bands B21 to B2n is extracted to one output of the optical splitter, and this outgoing optical signal Oo2 is sent to the downstream optical fiber cable 15 as a relay output WDM optical main signal (transmission signal). A graph 305 shows the output light Oo11. A graph 306 shows the output light Oo1n. The output light Oo11 to Oo1n containing optical components in the same wavelength bands B11 to B1n as those before the wavelength conversion is extracted at the other output of the optical demultiplexer by the demultiplexing of the optical demultiplexer. The output light Oo11 to Oo1n is input as an extraction signal to a plurality of detectors 11Aa to 11An for each wavelength via an optical fiber 15B. Here, since the emitted light Oo11 to Oo1n with a sufficiently high optical intensity is input to the detectors 11Aa to 11An, the detectors 11Aa to 11An can easily detect the transmission quality data for each wavelength at the position of the corresponding relay node. Of course, each detector 11Aa to 11An internally converts the input optical signal into an electrical signal and detects the transmission quality data by processing the electrical signal. FIG. 7 is a graph showing wavelength distribution when the transmission quality data of a signal not requiring wavelength conversion is detected using the detectors 11Aa to 11An for each wavelength. The graph 303 is as described in FIG. Graph 311 is compared with graph 304 in FIG. 6 in that the wavelength distribution of the transmitted optical signal Oo2 is changed from the wavelength band B21 to B2n after wavelength conversion to the wavelength band B11 to B1n before wavelength conversion. 6, graphs 312 and 313 show that the wavelength distribution of output light Oo11 to Oo1n is changed from the wavelength band B11 to B1n before the wavelength conversion to the wavelength band B21 to B2n after the wavelength conversion. FIG. 8 is a graph showing the wavelength distribution when a single detector equipped with a wavelength filter is used instead of the detectors 11Aa to 11An for each wavelength in the state of FIG. The graph 303 is as described in FIG. Graph 321 is as described for graph 304 in FIG. A graph 322 shows a signal input to the wavelength filter of the detector. By the splitting of the optical splitter, output light Oo1 containing optical components in the same wavelength band B11 to B1n as before the wavelength conversion is extracted at the other output of the optical splitter, and this output light Oo1 is input to the wavelength filter. A graph 323 shows a signal that is output from the wavelength filter of the detector and is to be detected. The wavelength filter selectively extracts an output light beam Oo1n of one wavelength band B1a from the wavelength bands B11 to B1n. Therefore, it is not necessary to install detectors 11Aa to 11An for each wavelength inside the optical transmission device 53. In this case, a single detector sequentially selects each of the wavelength bands B11 to B1n included in the WDM optical signal of the output light Oo1, converts them into electrical signals in order for each wavelength, and processes them, thereby making it possible to detect transmission quality data for each wavelength at the position of the relay node. FIG. 9 is a graph showing wavelength distribution when a single detector equipped with a wavelength filter is used instead of the detectors 11Aa to 11An for each wavelength in the state of FIG. The graph 303 is as described in FIG. Graph 331 is compared with graph 321 in FIG. 8 in that the wavelength distribution of the transmitted optical signal Oo2 is changed from the wavelength band B21 to B2n after wavelength conversion to the wavelength band B11 to B1n before wavelength conversion. Graphs 332 and 333 are compared with graphs 322 and 323 in FIG. 8 in that the wavelength distribution of output light Oo11 to Oo1n is changed from the waveband B11 to B1n before the wavelength conversion to the waveband B21 to B2n after the wavelength conversion. FIG. 10 is a graph showing wavelength distribution when an optical signal requiring wavelength conversion and an undesired optical signal are input to the same wavelength converter. The graph 303 is as described in FIG. A graph 341 shows the outgoing optical signal Oo2. The wavelength distribution of the outgoing optical signal Oo2 exists in both the waveband B11 to B1n before the wavelength conversion and the waveband B21 to B2n after the wavelength conversion. A graph 342 shows the output light Oo11. The wavelength distribution of the output light Oo11 also exists in the wavelength bands B11 to B1n before the wavelength conversion and in the wavelength bands B21 to B2n after the wavelength conversion. Hereinafter, the optical transmission device 53 of the present embodiment shown in FIG. 1 will be described in detail with reference to FIGS. 11 to 13 show an example in which the wavelength group input from the input port of the optical transmission device 53 is composed of two wavelength bands B1 and B2. 14 and 15 show an example in which the wavelength group input from the input port of the optical transmission device 53 is composed of a plurality of wavelength bands B1, B2, . . . , BK (K is a natural number equal to or greater than 2). The input wavelength group may be made up of a plurality of wavelength bands, or a plurality of partial wavelength regions may exist within one wavelength band. FIG. 11 is a configuration diagram of an optical transmission device 200A which is a first example of the optical transmission device 53 in FIG. In the optical transmission device 200A, a DEMUX 210A, a wavelength converter 220A, a WSS 230A (first WSS), and a cross connect 240A (incoming WSS 241A and outgoing WSS 242A, which are wavelength selective switches) are connected in order from an input port on the upstream side of an optical signal (1, M on the left side in the figure) to an output port on the downstream side (1, M on the right side in the figure). In addition, the WSS 230A is connected to a monitoring measuring instrument 290. The components in FIG. 11 include those already described below. The all-optical wavelength conversion unit 13A in FIG. 1 is implemented as a wavelength conversion unit 220A in FIG. Detectors 11Aa to 11An in FIG. 1 are implemented as monitor measuring device 290 in FIG. The optical demultiplexer in the all-optical wavelength conversion unit 13A described in FIG. 3 is implemented as the WSS 230A in FIG. The DEMUX 210A is a demultiplexer that separates the wavelength group (signals of wavelength bands B1+B2) input from the input port of the optical transmission device 200A into wavelength bands B1 and B2. The optical transmission device 200A connects the DEMUX 210A to the input port side of the wavelength conversion unit 220A. The DEMUX 210A separates an input signal having a plurality of wavelength components into signals having individual wavelength components that can be converted by the wavelength conversion unit 220A, and outputs the separated signals to each wavelength conversion unit 220A. Each wavelength conversion unit 220A generates a wavelength signal of another wavelength band (e.g., wavelength band B2) from a wavelength signal (e.g., wavelength band B1) input from DEMUX 210A, and outputs a signal of a wavelength group including the two wavelength bands B1 and B2 (output light Oout in Figure 6) to WSS 230A. The WSS 230A is a wavelength selective switch that demultiplexes the output light Oout output from the wavelength conversion unit 220A into a transmission signal and an extraction signal as follows: The following is an example of wavelength conversion from wavelength band B1 to wavelength band B2. For an input signal that requires wavelength conversion, the WSS 230A outputs the wavelength component (wavelength band B2) of the output light Oout after wavelength conversion as a transmission signal from the cross connect 240A to the output port. The WSS 230A also outputs the wavelength component (wavelength band B1) of the output light Oout before wavelength conversion as an extraction signal to the monitor measuring instrument 290. For an input signal that does not require wavelength conversion, the WSS 230A outputs the wavelength component (wavelength band B1) of the output light Oout before wavelength conversion as a transmission signal from the cross connect 240A to an output port. The WSS 230A also outputs the wavelength component (wavelength band B2) of the output light Oout after wavelength conversion as an extraction signal to the monitor measuring instrument 290. The output control of the WSS 230A is set in advance in the WSS 230A by the network controller 20, for example. The cross connect 240A selects a wavelength from an ingress WSS 241A located on the ingress side to an output port of the optical transmission device 200A via an egress WSS 242A located on the egress side, without electrically terminating the transmission signal. The monitoring measuring instrument 290 electrically terminates the extracted signal output from the WSS 230A to detect its transmission quality data. In the optical transmission device 200A in Fig. 11, a configuration is illustrated in which an extracted signal output based on input signals input from a plurality of input ports is commonly handled. However, a plurality of monitoring measuring instruments 290 (one for each input port) may be disposed in the optical transmission device 200A. With the above configuration, even for signals that do not require wavelength conversion, the extracted signal is output from the WSS 230A to the monitoring measurement instrument 290 without detouring the wavelength converter 220A. That is, the optical transmission device 200A is configured such that the wavelength converter 220A is disposed on the input port side, and all optical signals input to the optical transmission device 200A pass through the wavelength converter 220A. This allows the monitoring method to be applied to all optical signals. In addition, because the wavelength group input to the optical transmission device 200A is composed of two wavelength bands B1 and B2, the number of optical components through which the optical signal passes is relatively small, a total of four: "wavelength conversion unit 220A → WSS 230A → ingress WSS 241A → egress WSS 242A." This is expected to minimize the degradation of transmission quality caused by passing through optical components. FIG. 12 is a configuration diagram of an optical transmission device 200B which is a second example of the optical transmission device 53 in FIG. In the optical transmission device 200B, a DEMUX 210B, a wavelength converter 220B, and a cross connect 240B (an ingress WSS 241B (first WSS) and an egress WSS 242B) are connected in this order from the input port. The WSS 230A and the ingress WSS 241A of the optical transmission device 200A in Fig. 11 are integrated into an ingress WSS 241B in the optical transmission device 200B in Fig. 12. That is, the function of the WSS 230A is disposed on the ingress side of the cross connect 240A as the ingress WSS 241B. As a result, the optical transmission device 200B is expected to further reduce the number of optical components through which an optical signal passes, compared to the optical transmission device 200A, thereby further suppressing deterioration in transmission quality. FIG. 13 is a configuration diagram of an optical transmission device 200C which is a third example of the optical transmission device 53 in FIG. In the optical transmission device 200C, a DEMUX 210C, a wavelength conversion unit 220C, a cross connect 240C (an ingress WSS 241C (first WSS) and an egress WSS 242C), and a MUX 250C are connected in this order from the input port. The optical transmission device 200C has the following modifications to the optical transmission device 200B in FIG. The multi-band compatible egress WSS 242B is replaced with the single-band compatible egress WSS 242C. For example, the "B1 WSS" shown at the top is a WSS that supports the single band of wavelength band B1. Similarly, in the following, the single-band compatible WSSs among the WSSs are illustrated as "Bi WSS" (i = 1, 2, ...), and only the wavelength band Bi is input. A MUX 250C that multiplexes the signal light of each wavelength band is connected downstream of the output WSS 242C, and the MUX 250C is connected to an output port. The MUX 250C is a multiplexer that multiplexes signal light of multiple wavelength bands into one signal. That is, in the optical transmission device 200C, the MUX 250C is connected closer to the output port than the cross connect 240C. The MUX 250C outputs, from the output port, a signal obtained by multiplexing the transmission signals of the individual wavelength components output by the cross connect 240C. According to this optical transmission device 200C, in addition to the effects of the optical transmission device 200B, optical signals of each wavelength band B1, B2 are transmitted between the DEMUX 210C and the wavelength conversion unit 220C, and between the egress WSS 242C and the MUX 250C, so that optical amplifiers suitable for each wavelength group (low-cost optical amplifiers that amplify only a single wavelength band) can be arranged. FIG. 14 is a configuration diagram of an optical transmission device 200D which is a fourth example of the optical transmission device 53 in FIG. In the optical transmission device 200D, a WSS 230D (second WSS), a wavelength conversion unit 220D, and a cross connect 240D (WSS 241D (first WSS) and WSS 242D) are connected in this order from the input port. The wavelength group input from the input port of the optical transmission device 200D is composed of a plurality of wavelength bands B1, B2, ..., BK. The all-optical wavelength conversion unit 13A in FIG. 1 is implemented as the wavelength conversion unit 220D in FIG. Detectors 11Aa to 11An in FIG. 1 are implemented as a monitoring measuring device 290 in FIG. The optical demultiplexer in the all-optical wavelength conversion unit 13A described in FIG. 3 is implemented as the WSS 241D in FIG. In the optical transmission device 200D, the WSS 230D is connected closer to the input port than the wavelength conversion unit 220D. The WSS 230D demultiplexes an input signal having multiple wavelength components into signals having individual wavelength components that can be converted by the wavelength conversion unit 220D, and outputs the demultiplexed signals to each wavelength conversion unit 220D. That is, the WSS 230D demultiplexes the optical signals of the multiple wavelength bands B1, B2, ..., BK input from the input port into optical signals of a single wavelength band that each wavelength conversion unit 220D can handle. For example, the wavelength conversion unit 220D "B1 → B2" illustrated at the top converts the input wavelength band B1 to the wavelength band B2 and outputs optical signals of the wavelength bands B1 and B2. Therefore, the WSS 230D outputs the optical signal of the wavelength band B1 to the wavelength conversion unit 220D "B1 → B2" from among the optical signals of the multiple wavelength bands B1, B2, ..., BK input. FIG. 15 is a configuration diagram of an optical transmission device 200E which is a fifth example of the optical transmission device 53 in FIG. In the optical transmission device 200E, a DEMUX 210E, a WSS 230E, a wavelength conversion unit 220E, a cross connect 240E (a WSS 241E (first WSS) and a WSS 242E), and a MUX 250E are connected in this order from the input port. The optical transmission device 200E has the following changes made to the optical transmission device 200D in FIG. 14. The WSS 230D (compatible with multiple bands) in Fig. 14 is replaced with a WSS 230E (compatible with a single band) in Fig. 15. With this replacement, and further, by disposing a DEMUX 210E upstream of the WSS 230E, the WSS 230E inputs a single wavelength band. The WSS 242D (compatible with multiple bands) in Fig. 14 is replaced with a WSS 242E (compatible with a single band) in Fig. 15. With this replacement, and further by disposing a MUX 250E downstream of the WSS 242E, the WSS 230E inputs and outputs a single wavelength band. As a result, the optical transmission device 200E has a larger number of WSSs than the optical transmission device 200D, but the number of multi-band compatible WSSs can be reduced, thereby reducing device costs. Furthermore, according to the optical transmission device 200E, in addition to the effects of the optical transmission device 200D, optical signals of each of the wavelength bands B1 and B2 are transmitted between the DEMUX 210E and the WSS 230E, and between the WSS 242E and the MUX 250E, so that optical amplifiers suitable for each wavelength group can be arranged. In addition, the optical transmission device 200A of the first example has an optical signal passing through the WSS more times than the second to fifth examples, and therefore is desirably used as a backbone node of a core network having a large number of input / output ports. On the other hand, the second example (optical transmission device 200B) to the fifth example (optical transmission device 200E) are preferably applied to a simple network configuration such as a ring network having a small number of input / output ports. Furthermore, in the second example (optical transmission device 200B) and the fourth example (optical transmission device 200D), the number of optical components used is small, and therefore they are suitable for applications in which the housing space of the entire device is reduced. [effect] The optical transmission device 200A of the present invention is an optical transmission device 200A that performs an optical relay process of outputting an input signal, which is an input optical signal, as a transmission signal to another device, The optical transmission device 200A includes an all-optical wavelength conversion unit 13A, a WSS 230A, a cross connect 240A, and a monitoring measuring instrument 290. The all-optical wavelength conversion unit 13A converts the wavelength of the input signal to the optical transmission device 200A regardless of whether or not the wavelength conversion of the input signal is required, thereby outputting the output light Oout including both wavelength components before and after the wavelength conversion to the WSS 230A. WSS230A, For an input signal that requires wavelength conversion, the wavelength component of the output light Oout after wavelength conversion is output as a transmission signal from the cross connect 240A to an output port, and the wavelength component of the output light Oout before wavelength conversion is output as an extraction signal to the monitor measuring instrument 290. For an input signal that does not require wavelength conversion, the wavelength component of the output light Oout before wavelength conversion is output as a transmission signal from the cross connect 240A to an output port, and the wavelength component of the output light Oout after wavelength conversion is output as an extraction signal to the monitor measuring instrument 290. A monitoring measuring instrument 290 electrically terminates the extracted signal output from the WSS 230A, thereby detecting the transmission quality data. As a result, the optical transmission device 200A passes all optical signals passing through the all-optical wavelength converter 13A, and the WSS 230A selects appropriate transmission signals and extraction signals depending on whether or not wavelength band conversion is required. Therefore, the optical transmission device 200A can be a monitoring target regardless of whether or not wavelength band conversion is required. The present invention is characterized in that the monitoring measuring instrument 290 is configured to commonly handle an extracted signal that is output based on input signals input from a plurality of input ports. This allows the optical transmission devices 200A to 200E to reduce the number of monitoring measuring devices 290, thereby reducing device costs. The present invention is characterized in that the WSS 230A is disposed on the ingress side within the cross connect 240A. As a result, the optical transmission device 200B is expected to minimize degradation of transmission quality by reducing the number of optical components through which an optical signal passes. In the present invention, the optical transmission device 200C is connected with the DEMUX 210C closer to the input port than the all-optical wavelength conversion unit 13A, The DEMUX 210C is characterized in that it separates, from an input signal having a plurality of wavelength components, signals having individual wavelength components that can be converted by the all-optical wavelength conversion units 13A and outputs the separated signals to the all-optical wavelength conversion units 13A. This allows the optical transmission device 200C to arrange optical amplifiers suitable for each wavelength group on the input port side. In the present invention, the optical transmission device 200D has a WSS 230D connected to the input port side of the all-optical wavelength conversion unit 13A, The WSS 230D is characterized in that it splits an input signal having a plurality of wavelength components into signals having individual wavelength components that can be converted by the all-optical wavelength conversion units 13A and outputs the split signals to each all-optical wavelength conversion unit 13A. As a result, by using the multi-band compatible WSS 230D, the optical transmission device 200D can reduce the number of optical components compared to using a single-band compatible WSS. In the present invention, the optical transmission device 200D has a MUX 250C connected closer to the output port than the cross connect 240A, MUX 250C is characterized in that it outputs a signal obtained by multiplexing the transmission signals of the individual wavelength components output by cross connect 240A from an output port. This allows the optical transmission device 200D to arrange optical amplifiers suitable for each wavelength group on the output port side. 11a-11n TPD 11Aa to 11An detectors 13A All-optical wavelength conversion section 14 Excitation light source 15 Optical fiber cable 16 Optical multiplexer 17 Nonlinear Optical Media 20 Network Controller 51 to 55 Optical transmission equipment 100 Optical transmission system 200A, 200B, 200C, 200D, 200E Optical transmission device 210A, 210B, 210C, 210E DEMUX 220A to 220E Wavelength conversion unit 230A WSS (1st WSS) 241B, 241C Entry side WSS (1st WSS) 241D, 241E WSS (1st WSS) 230D WSS (2nd WSS) 250C, 250E MUX 290 Monitor Measuring Instrument

Claims

1. An optical transmission device that performs optical relay processing to output an input signal, which is an input optical signal, as a transmission signal to another device, the optical transmission device includes a wavelength conversion unit, a first wavelength selective switch (WSS), a cross connect, and a monitoring measuring instrument; the wavelength conversion unit converts the wavelength of the input signal regardless of whether wavelength conversion of the input signal to the optical transmission device is necessary, and outputs output light including wavelength components both before and after wavelength conversion to the first WSS; The first WSS is For the input signal requiring wavelength conversion, a wavelength component of the output light after wavelength conversion is output as the transmission signal from the cross connect to an output port, and a wavelength component of the output light before wavelength conversion is output as an extraction signal to the monitoring measuring instrument; For the input signal that does not require wavelength conversion, a wavelength component of the output light before wavelength conversion is output as the transmission signal from the cross connect to an output port, and a wavelength component of the output light after wavelength conversion is output as the extraction signal to the monitoring measuring instrument; The monitoring measuring instrument electrically terminates the extracted signal output from the first WSS to detect its transmission quality data. Optical transmission equipment.

2. The monitoring measuring instrument is configured to commonly handle the extracted signal output based on the input signals input from a plurality of input ports.

2. The optical transmission device according to claim 1.

3. The first WSS is arranged on the ingress side of the cross connect.

2. The optical transmission device according to claim 1.

4. the optical transmission device has a MUX connected to a side of the output port relative to the cross connect; The MUX outputs a signal obtained by multiplexing the transmission signals of the individual wavelength components output by the cross connect from an output port.

2. The optical transmission device according to claim 1.

5. An optical transmission device that performs optical relay processing to output an input signal, which is an input optical signal, as a transmission signal to another device, the optical transmission device includes a wavelength conversion unit and a first WSS, the wavelength conversion unit converts the wavelength of the input signal regardless of whether wavelength conversion of the input signal to the optical transmission device is necessary, and outputs output light including wavelength components both before and after wavelength conversion to the first WSS; The first WSS is For the input signal that requires wavelength conversion, a wavelength component of the output light after wavelength conversion is output as the transmission signal, and a wavelength component of the output light before wavelength conversion is output as an extraction signal; For the input signal that does not require wavelength conversion, a wavelength component of the output light before wavelength conversion is output as the transmission signal, and a wavelength component of the output light after wavelength conversion is output as the extracted signal. Optical transmission equipment.

6. the optical transmission device has a DEMUX connected to an input port closer to the wavelength conversion unit; The DEMUX is characterized in that it separates signals having individual wavelength components that can be converted by the wavelength conversion units from the input signal having a plurality of wavelength components and outputs the separated signals to the wavelength conversion units.

6. The optical transmission device according to claim 1.

7. the optical transmission device connects a second WSS closer to an input port than the wavelength conversion unit; The second WSS is characterized in that it demultiplexes the input signal having a plurality of wavelength components into signals having individual wavelength components that can be converted by the wavelength conversion units and outputs the demultiplexed signals to each of the wavelength conversion units.

6. The optical transmission device according to claim 1.

8. The optical transmission device includes a wavelength conversion unit, a first WSS, a cross connect, and a monitoring measuring instrument, The optical transmission device performs optical relay processing to output an input signal, which is an input optical signal, to another device as a transmission signal. the wavelength conversion unit converts the wavelength of the input signal regardless of whether wavelength conversion of the input signal to the optical transmission device is necessary, and outputs output light including wavelength components both before and after wavelength conversion to the first WSS; The first WSS is For the input signal requiring wavelength conversion, a wavelength component of the output light after wavelength conversion is output as the transmission signal from the cross connect to an output port, and a wavelength component of the output light before wavelength conversion is output as an extraction signal to the monitoring measuring instrument; For the input signal that does not require wavelength conversion, a wavelength component of the output light before wavelength conversion is output as the transmission signal from the cross connect to an output port, and a wavelength component of the output light after wavelength conversion is output as the extraction signal to the monitoring measuring instrument; The monitoring measuring instrument electrically terminates the extracted signal output from the first WSS to detect its transmission quality data. Optical transmission method.

9. The optical transmission device includes a wavelength conversion unit and a first WSS, The optical transmission device performs optical relay processing to output an input signal, which is an input optical signal, to another device as a transmission signal. the wavelength conversion unit converts the wavelength of the input signal regardless of whether wavelength conversion of the input signal to the optical transmission device is necessary, and outputs output light including wavelength components both before and after wavelength conversion to the first WSS; The first WSS is For the input signal that requires wavelength conversion, a wavelength component of the output light after wavelength conversion is output as the transmission signal, and a wavelength component of the output light before wavelength conversion is output as an extraction signal; For the input signal that does not require wavelength conversion, a wavelength component of the output light before wavelength conversion is output as the transmission signal, and a wavelength component of the output light after wavelength conversion is output as the extracted signal. Optical transmission method.