Optical signal multiplexing device, control device, optical transmission system, confirmation method, and program

Abstract

Provided is an optical transmission system which is for connecting, using an optical wavelength path and via an optical signal multiplexing device, an optical user terminal comprising an optical transceiver and another optical user terminal comprising an optical transceiver. This optical signal multiplexing device comprises: an optical frame monitoring unit for monitoring an optical frame of the optical user terminal; and an optical signal transmission / reception unit for transmitting an optical signal received from the optical user terminal to the optical frame monitoring unit.

Description

Optical signal multiplexing device, control device, optical transmission system, verification method, and program

[0001] The present invention relates to an optical transmission system for transmitting optical signals.

[0002] In a conventional optical transmission system, a plurality of optical transmission devices are provided as carrier facilities, and the optical transmission devices are connected to user terminals via Ethernet (registered trademark) or the like.

[0003] Each optical transmission device includes a transponder and an optical signal multiplexing unit, and a carrier (telecommunications operator) sets up an optical wavelength path between a transponder of an optical transmission device at one location and a transponder of an optical transmission device at another location. When the transponder of the optical transmission device at one location receives a signal such as Ethernet (registered trademark) as an optical signal from a user terminal, it converts the optical signal into an electrical signal, adds error correction codes and the like for long-distance transmission, converts the electrical signal back into an optical signal, and transmits the optical signal through the optical wavelength path.

[0004] Telecommunications Technology Committee, "TR-1004 Technical Report on Optical Transport Network (OTN) Management, First Edition," TTC Technical Report, February 20, 2002, https: / / www.ttc.or.jp / application / files / 6015 / 5435 / 4555 / TR-1004v1.pdf

[0005] As described above, in conventional technology, since the transponder in the optical transmission device is the carrier equipment, it is possible to guarantee that the optical frame of the optical signal transmitted from the optical transceiver in the transponder is an appropriate optical frame (for example, conforming to the optical frame that can be transmitted by the optical signal multiplexing unit).

[0006] On the other hand, in an APN (All Photonics Network), for example, the optical transmission equipment is assumed to be separable and the transponder is built into the user terminal. In this configuration, user terminals are directly connected to each other via optical wavelength paths, which is expected to enable low-latency and wide-bandwidth communications.

[0007] When a transponder is incorporated into a user terminal (called an optical user terminal), the transponder becomes user equipment. Therefore, it cannot be guaranteed that the optical frame of the optical signal transmitted from the optical transceiver in the transponder of the optical user terminal is appropriate for that optical user terminal. If the optical user terminal transmits an optical signal in an inappropriate optical frame, the optical signal cannot be transmitted appropriately in the optical transmission system.

[0008] The present invention has been made in consideration of the above points, and aims to provide a technology that enables appropriate transmission of optical signals even when an optical user terminal equipped with an optical transceiver is used in an optical transmission system.

[0009] According to the disclosed technology, there is provided an optical signal multiplexing device in an optical transmission system for connecting an optical user terminal equipped with an optical transceiver to another optical user terminal equipped with an optical transceiver by an optical wavelength path via an optical signal multiplexing device, the optical signal multiplexing device comprising: an optical frame monitoring unit that monitors optical frames of the optical user terminal; and an optical signal transmitting / receiving unit that transmits optical signals received from the optical user terminal to the optical frame monitoring unit.

[0010] The disclosed technology provides a technology that enables appropriate transmission of optical signals even when an optical user terminal equipped with an optical transceiver is used in an optical transmission system.

[0011] FIG. 1 is a diagram illustrating an example of the configuration of a conventional optical transmission system. FIG. 2 is a diagram illustrating an example of the configuration when an optical transceiver is provided on the user side. FIG. 3 is a diagram illustrating an example of the overall configuration of an optical transmission system according to an embodiment of the present invention. FIG. 4 is a diagram illustrating an example of the overall configuration of an optical transmission system according to an embodiment of the present invention. FIG. 5 is a diagram illustrating a configuration of a controller 100. FIG. 6 is a diagram illustrating a configuration of an optical signal multiplexing device 10. FIG. 7 is a diagram illustrating a specific example configuration of an optical signal multiplexing device 10. FIG. 8 is a diagram illustrating a specific example configuration of an optical signal multiplexing device 10. FIG. 9 is a sequence diagram according to an embodiment 1. FIG. 10 is a sequence diagram according to an embodiment 2. FIG. 11 is a diagram illustrating an example of the hardware configuration of a controller 100.

[0012] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The embodiment described below is merely an example, and the embodiment to which the present invention is applied is not limited to the following embodiment.

[0013] In the following embodiments, the optical signal multiplexing device is considered to be carrier equipment and the optical user terminal is considered to be user equipment, but this classification of equipment is merely an example. The technology according to the present invention is applicable regardless of the classification of equipment. First, the conventional technology and problems will be described in detail with reference to the drawings, and then the technology according to the present embodiment will be described in detail. Note that the carrier may also be called a NW (network) operator. Below, the conventional technology, assumptions, and problems will be described in more detail, and then the technology according to the present embodiment will be described.

[0014] (Regarding Prior Art) As described above, in a conventional optical transmission system (optical transmission network), optical transmission equipment is installed in carrier facilities, and the optical transmission equipment and user terminals are connected via Ethernet (registered trademark) or the like.

[0015] Fig. 1 shows an example of the configuration of a conventional optical transmission system. In the optical transmission system shown in Fig. 1, optical transmission equipment 1-1 and optical transmission equipment 1-2 are provided as carrier equipment. User terminals 2-1 and 2-2 are connected to the optical transmission equipment 1-1 and the optical transmission equipment 1-2, respectively, via Ethernet (registered trademark) or the like. In the following explanation, when there is no need to distinguish between the two opposing equipment, the explanation will be made without adding "-1", "-2", etc.

[0016] As shown in FIG. 1, the optical transmission device 1 has a transponder 3 and an optical signal multiplexing unit 4. The transponder 3 includes an optical transceiver. A carrier (network operator) sets up an optical wavelength path between the transponder 3-1 of the optical transmission device 1-1 and the transponder 3-2 of the optical transmission device 1-2. When the transponder 3 receives a signal (optical signal) such as Ethernet (registered trademark) from the user terminal 2, it converts the optical signal into an electrical signal, adds an error correction code or the like for long-distance transmission, converts the electrical signal into an optical signal, and transmits the optical signal through the optical wavelength path.

[0017] The optical signal multiplexing unit 4 in the optical transmission device 1 has a configuration including, for example, WDM, Add / Drop+WXC, etc. The optical transmission devices are connected by optical fibers, and in some cases, optical transmission devices for relaying are also provided.

[0018] The optical transceiver in the transponder 3 creates and transmits an optical signal in a predetermined optical signal format (such as frequency width, modulation method, and optical signal intensity). Because the optical signal from the optical transceiver conforms to the predetermined optical signal format, the optical signal multiplexer 4 can multiplex optical signals from multiple transponders without interfering with each other, allowing multiple optical signals to be transmitted over a single optical fiber.

[0019] (Premise) As mentioned above, in an APN (All Photonic Network) or the like, it is assumed that the optical transmission equipment 1 is configured to be separable and the transponder 3 is incorporated into the user terminal 2. In this configuration, since the user terminals 2 are directly connected to each other via optical wavelength paths, it is expected that low-latency, wideband communications can be realized. The following description focuses on the optical transceiver included in the transponder 3. A user terminal equipped with an optical transceiver is called an optical user terminal.

[0020] In the above scenario, users own optical user terminals, and a network service is provided that allows a variety of optical transceivers to connect to the network. An example of a system configuration based on the above scenario is shown in Figure 2. Note that the configuration shown in Figure 2 is not publicly known technology.

[0021] 2, optical user terminals 20-1A, 20-1B, 20-2A, and 20-2B are connected to the optical signal multiplexer 10. The optical user terminals 20-1A and 20-2A each have an optical transceiver of model number A, and the optical user terminals 20-1B and 20-1B each have an optical transceiver of model number B.

[0022] In the example of FIG. 2, communication is performed between the optical user terminals 20-1A and 20-2A via an optical wavelength path, and communication is performed between the optical user terminals 20-1B and 20-2B via an optical wavelength path.

[0023] In this embodiment, in order to provide the above-mentioned network services, in order to realize interconnection between any optical user terminals, the specifications of the optical transceivers (hereinafter referred to as "specs") in each optical user terminal are registered with the network operator, and the network operator mediates the connection.

[0024] The specifications of an optical transceiver include not only optical signal attributes such as wavelength, but also the characteristics of the DSP (Digital Signal Processor) and the format of the OTN (Optical Transport Network) frame (see, for example, the Open ROADM Multi-Source Agreement, http: / / www.openroadm.org / ).

[0025] Network operators monitor whether the specifications of the optical transceivers registered by users are the same as those of the optical transceivers actually connected to the network. Regarding optical signal monitoring, conventional technologies define the monitoring of optical signal attributes, such as the wavelength and optical intensity of the optical signal. Furthermore, as described in Non-Patent Document 1, conventional technologies assume that monitoring of optical frames, such as DSP characteristics and OTN frame formats, is performed at the terminal.

[0026] (Regarding the Issues) When optical user terminals are deployed at user locations as in the configuration shown in Fig. 2, there is no guarantee that the optical user terminals will transmit appropriate optical frames (i.e., optical frames that comply with the contract terms). Therefore, it is necessary for the network operator to confirm whether the optical frames comply with the contract terms. For example, if the contract terms state that "optical transceivers with model number 1 must be used in the optical user terminal," then the optical frames comply with the contract terms if the optical frames are consistent with the optical frames of the optical transceivers with model number 1. Furthermore, the compliance of optical frames with the contract terms may be expressed more specifically as the format of the optical frames complying with the contract terms.

[0027] However, conventional technology has a problem in that in a system configuration in which optical user terminals are deployed at user locations, there is no technology that allows network operators to monitor the specifications of optical frames among the specifications of optical transceivers registered by users.

[0028] (Outline of the embodiment) An outline of a technology for solving the above problems will be described. Fig. 3 shows an example of the schematic configuration of an optical transmission system according to the present embodiment. As shown in Fig. 3, an optical frame monitoring unit 13 is provided in the NW. The optical frame monitoring unit 13 may also be called a monitoring terminal. In addition, in the present embodiment, a configuration for optical multiplex transmission including the optical frame monitoring unit 13 is called an optical signal multiplexing device 10.

[0029] 3, similarly to the case of Fig. 2, optical user terminals 20-1A, 20-1B, 20-2A, and 20-2B are connected to the optical signal multiplexer 10. The optical user terminals 20-1A and 20-2A each have an optical transceiver of model number A, and the optical user terminals 20-1B and 20-1B each have an optical transceiver of model number B.

[0030] The optical frame monitoring unit 13A corresponds to the optical transceiver of model number A, and the optical frame monitoring unit 13B corresponds to the optical transceiver of model number B.

[0031] 3, communication from the optical user terminal 20-1 is connected to the optical frame monitoring unit 13. The optical frame monitoring unit 13 monitors the optical frames from the optical user terminal 20, checks the specifications of the optical frames, and determines whether the optical user terminal 20 can communicate based on the check results (monitoring results). The determination of whether the optical user terminal 20 can communicate or whether the optical frames are appropriate may be made by the optical frame monitoring unit 13 or by an optical signal compliance confirmation unit 130 of the controller 100, which will be described later.

[0032] Note that checking the specifications of an optical frame means, for example, checking which model number of the optical transceiver the received optical frame is from.

[0033] When connecting communications from the optical user terminal 20-1 to the optical frame monitoring unit 13, an optical branching device or a distribution device (FXC) may be used. When an optical branching device is used, continuous monitoring is possible. When an FXC is used, operation can be switched between monitoring mode and communication mode (for example, setting up monitoring mode before communication).

[0034] Here, the optical transceiver owned by the user and the optical frame monitoring unit 13 in the NW must be a combination that allows interconnectivity. Interconnectivity means, for example, that the model number of the optical transceiver owned by the user (equipped in the optical user terminal) and the model number of the optical transceiver equipped in the optical frame monitoring unit 13 are the same.

[0035] For example, based on the model number of the optical transceiver declared by the user, the network operator can monitor multiple types of optical frames by allocating the communication of the optical user terminal 20 of the user to the optical frame monitoring unit 13 to which the user is connected. Note that the model number of the optical transceiver is an example of the type of optical transceiver.

[0036] The configuration and operation of the optical transmission system according to this embodiment will be described in more detail below.

[0037] (Overall Configuration Example) Fig. 4 shows an overall configuration example of an optical transmission system according to this embodiment. As shown in Fig. 4, an optical signal multiplexing device 10-1 and an optical signal multiplexing device 10-2 are provided as carrier facilities. Two optical user terminals 20-1A and 20-1B are connected to the optical signal multiplexing device 10-1 as user facilities, and two optical user terminals 20B are connected to the optical signal multiplexing device 10-2 as user facilities. Each optical user terminal 20 is provided with an optical transceiver 25.

[0038] Also provided is a controller 100 that controls the optical user terminals 20 and the optical signal multiplexer 10. The controller may also be called a control device. The controller 100 is capable of communicating with each of the optical user terminals 20 and the optical signal multiplexer 10 via a control line.

[0039] The configuration of each device will be described in detail below.

[0040] (Controller 100) Fig. 5 shows an example of the configuration of the controller 100. As shown in Fig. 5, the controller 100 includes an optical user terminal connection acceptance unit 110, a connection relationship confirmation unit 120, an optical signal compliance confirmation unit 130, an optical user terminal communication unit 140, and an optical signal multiplexing communication unit 150. The functions of each unit are as follows:

[0041] The optical user terminal connection acceptance unit 110 accepts requests for optical user terminal connections. The optical user terminal connection acceptance unit 110 also causes the connection relationship confirmation unit 120 to confirm whether the optical user terminal 20 attempting to connect is properly connected, and causes the optical signal compliance confirmation unit 130 to confirm whether the optical frame of the optical user terminal 20 is an appropriate optical frame. The optical user terminal connection acceptance unit 110 responds with the confirmation result to the request source.

[0042] The connection relationship confirmation unit 120 confirms whether the optical user terminal 20 to be connected is correctly connected to the optical signal multiplexer 10. A correct connection means, for example, that when the optical user terminal 20 should be connected to a specific IF of the optical signal multiplexer 10, the optical user terminal 20 is actually connected to the specific IF.

[0043] Based on the monitoring results of the optical frame monitoring unit 13, the optical signal compliance confirmation unit 130 verifies whether the optical frame of the optical user terminal 20 is a correct optical frame (e.g., an optical frame that matches the model number of the optical transceiver registered by the user).

[0044] The optical user terminal communication unit 140 performs various communications for controlling the optical user terminal 20, including issuing instructions for transmitting and receiving optical signals. Furthermore, when communicating with the optical user terminal 20, each functional unit in the controller 100 communicates via the optical user terminal communication unit 140.

[0045] The optical signal multiplexing communication unit 150 performs various communications for controlling the optical signal multiplexing device 10. This control includes setting the optical signal receiving unit 12 to a monitoring mode and issuing an instruction to perform monitoring by the optical signal monitoring unit 13. Furthermore, when communicating with the optical signal multiplexing device 10, each functional unit in the controller 100 communicates via the optical signal multiplexing communication unit 150.

[0046] (Optical signal multiplexing device 10) Fig. 6 shows an example of the configuration of the optical signal multiplexing device 10. As shown in Fig. 6, the optical signal multiplexing device 10 includes a controller communication unit 11, an optical signal transmitting / receiving unit 12, an optical frame monitoring unit 13, an optical signal multiplexing / demultiplexing unit 14, and an optical signal transmitting / receiving unit 15.

[0047] The controller communication unit 11 performs various communications for receiving control from the controller 100 .

[0048] The optical signal transmitter / receiver 12 is connected to the optical user terminal 20 and transmits and receives optical signals. Generally, transmission and reception are performed at a specific wavelength. The specific wavelength refers to a frequency band along a frequency grid.

[0049] The optical frame monitoring unit 13 receives optical signals from the optical signal transmitting / receiving unit 12 and monitors the optical frames. An optical frame monitoring unit 13 is provided for each type of optical transceiver. More specifically, for example, an optical frame monitoring unit 13 is provided for each model number of the optical transceiver.

[0050] The optical signal multiplexer / demultiplexer 14 multiplexes or switches the path of optical signals between the optical signal transmitter / receiver 12 and the optical signal transmitter / receiver 15 .

[0051] The optical signal transmitting / receiving unit 15 is connected to other optical signal multiplexing devices 10 and transmits and receives optical signals. Generally, a plurality of wavelengths are multiplexed and transmitted / received.

[0052] (Optical User Terminal 20) Fig. 7 shows an example of the configuration of the optical user terminal 20. As shown in Fig. 7, the optical user terminal 20 includes a controller communication unit 21, an electrical-to-optical signal conversion unit 22, and an optical signal transmission / reception unit 23.

[0053] The controller communication unit 21 performs various communications to receive control from the controller 100. The electrical-to-optical signal conversion unit 22 converts electrical signals and optical signals. The optical signal transmission / reception unit 23 connects to the optical signal multiplexer 10 and transmits and receives optical signals. The combination of the electrical-to-optical signal conversion unit 22 and the optical signal transmission / reception unit 23 corresponds to an optical transceiver.

[0054] (Specific Examples of Optical Signal Multiplexer 10) As specific examples of the optical signal multiplexer 10, examples 1 and 2 will be described.

[0055] <Optical signal multiplexing device 10: Example 1> Fig. 8 shows a configuration example of the optical signal multiplexing device 10 in Example 1. As shown in Fig. 8, in Example 1, the optical signal transmitting / receiving unit 12 includes an IF and an optical branching device, the optical signal multiplexing / demultiplexing unit 14 includes an Add / Drop and a WXC, and the optical signal transmitting / receiving unit 15 includes an IF.

[0056] In this configuration, the optical branching device sends optical signals from the IF to which the optical user terminal 20 is connected to the optical frame monitoring unit 13 and also to the optical signal multiplexing / demultiplexing unit 14. This enables constant monitoring during communication between opposing optical user terminals.

[0057] <Optical signal multiplexing device 10: Example 2> Fig. 9 shows a configuration example of the optical signal multiplexing device 10 in Example 2. As shown in Fig. 9, Example 2 includes an IF and an FXC (Fiber Cross Connect) as the optical signal transmitting / receiving unit 12, an Add / Drop and a WXC as the optical signal multiplexing / demultiplexing unit 14, and an IF as the optical signal transmitting / receiving unit 15.

[0058] In this configuration, only the IF set to the monitoring mode by FXC sends an optical signal to the optical frame monitoring unit 13. This eliminates the need for a monitoring function for all IFs, thereby reducing costs. In addition, since the IF set to the monitoring mode does not send an optical signal to the optical signal multiplexing / demultiplexing unit 14, interference with other optical signals can be prevented in the monitoring mode.

[0059] An example of operation of the optical transmission system according to this embodiment will be described below. An example of operation in which an optical branching device is used in the optical signal transmitting / receiving unit 12 of the optical signal multiplexing device 10 as shown in Fig. 8 will be described as Example 1, and an example of operation in which an FXC (distribution device) is used in the optical signal transmitting / receiving unit 12 of the optical signal multiplexing device 10 as shown in Fig. 9 will be described as Example 2.

[0060] (Operation Example: Example 1) An operation example of the system in Example 1 will be described with reference to the sequence diagram shown in Fig. 10. In the example of Fig. 10, there is an external system 200 that is used by a user or an operator.

[0061] In S1, the external system 200 transmits a connection request for a new optical user terminal 20-1A to the controller 100. The connection request includes (A) information (such as an IP address) used by the controller 100 to communicate with the optical user terminal 20, and (B) information indicating which IF connects the optical user terminal 20 to the optical signal multiplexer 10. The optical user terminal connection accepting unit 110 of the controller 100 acquires this information.

[0062] In S2, the optical user terminal communication unit 140 of the controller 100 uses (A) to communicate with the optical user terminal 20 and confirms the presence of the optical user terminal 20. In addition, the connection relationship confirmation unit 120 uses (B) to confirm that the optical user terminal 20 is connected to the correct IF.

[0063] In S3, the optical user terminal communication unit 140 of the controller 100 communicates with the optical user terminal 20 and acquires information on the optical signal format (e.g., ODU (Optical-channel Data Unit) type, transmission mode, wavelength) supported by the optical user terminal 20-1A. In addition to the optical signal format, the optical user terminal communication unit 140 may also acquire the model number of the optical transceiver included in the optical user terminal 20-1A in S3.

[0064] In S4, the optical user terminal communication unit 140 of the controller 100 selects the optical frame monitoring unit 13A that is compatible with the optical signal format supported by the optical user terminal 20-1A, which was acquired in S3. If the model number of the optical transceiver included in the optical user terminal 20-1A is acquired in S3, the optical frame monitoring unit 13A may be selected based on that model number.

[0065] In S5, the optical signal multiplexing communication unit 150 of the controller 100 sets the optical branching device so that the optical signal transmitted from the connection IF with the optical user terminal 20-1A is sent to the optical frame monitoring unit 13A selected in S4.

[0066] In S6, the optical user terminal communication unit 140 of the controller 100 communicates with the optical user terminal 20 and instructs it to transmit an optical signal in the supported optical signal format. In S7, the optical user terminal connection acceptance unit 110 of the controller 100 returns a connection response to the external system 200.

[0067] In S8, the optical user terminal 20, in accordance with the instruction in S6, transmits an optical signal to the optical signal multiplexer 10. The optical signal transmitted from the optical user terminal 20 is transmitted to the optical user terminal 20-2A, which is the communication partner, and also to the optical frame monitoring unit 13A.

[0068] The optical frame monitoring unit 13A of the optical signal multiplexing device 10 monitors the optical frames of the optical signal received from the optical user terminal 20-1A. If the optical frame monitoring unit 13A confirms that the optical frames comply with the contract conditions of the optical user terminal 20-1A, it allows communication to continue.

[0069] In S9, if the optical frame monitoring unit 13A of the optical signal multiplexing device 10 determines that the optical frame does not comply with the contract conditions of the optical user terminal 20-1A, it transmits a communication cutoff request (an example of a monitoring result) to the controller 100. The optical signal compliance confirmation unit 130 of the controller 100 receives the communication cutoff request.

[0070] In S10, the optical signal compliance confirmation unit 130 of the controller 100 determines that the optical frame does not comply with the contract conditions of the optical user terminal 20-1A, and communicates with the optical user terminal 20-1A via the optical user terminal communication unit 140 to instruct it to stop transmitting the optical signal.

[0071] Here, it is assumed that the optical user terminal 20-2A is also transmitting an optical signal, and in S11, the optical signal compliance confirmation unit 130 of the controller 100 communicates with the optical user terminal 20-2A via the optical user terminal communication unit 140 and instructs it to stop transmitting the optical signal.

[0072] (Operation Example: Example 2) Next, an operation example of the system in Example 2 will be described with reference to the sequence diagram shown in Fig. 11. In the example of Fig. 11, there is also an external system 200 that is used by a user or an operator.

[0073] In S1, the external system 200 transmits a connection request for a new optical user terminal 20-1A to the controller 100. The connection request includes (A) information (such as an IP address) used by the controller 100 to communicate with the optical user terminal 20, and (B) information indicating which IF connects the optical user terminal 20-1A to the optical signal multiplexer 10. The optical user terminal connection accepting unit 110 of the controller 100 acquires this information.

[0074] In S2, the optical user terminal communication unit 140 of the controller 100 uses (A) to communicate with the optical user terminal 20-1A and confirms that the optical user terminal 20-1A is present. Also, the connection relationship confirmation unit 120 uses (B) to confirm that the optical user terminal 20-1A is connected to the correct IF.

[0075] In S3, the optical user terminal communication unit 140 of the controller 100 communicates with the optical user terminal 20-1A and acquires information on the optical signal format (e.g., ODU (Optical-channel Data Unit) type, transmission mode, wavelength) supported by the optical user terminal 20-1A. In addition to the optical signal format, the optical user terminal communication unit 140 may also acquire the model number of the optical transceiver included in the optical user terminal 20-1A in S3.

[0076] In S4, the optical user terminal communication unit 140 of the controller 100 selects the optical frame monitoring unit 13A that is compatible with the optical signal format supported by the optical user terminal 20-1A, which was acquired in S3. If the model number of the optical transceiver included in the optical user terminal 20-1A is acquired in S3, the optical frame monitoring unit 13A may be selected based on that model number.

[0077] In S5, the optical signal multiplexing communication unit 150 of the controller 100 sets the FXC so that the optical signal transmitted from the connection IF with the optical user terminal 20-1A is sent to the optical frame monitoring unit 13A selected in S4, and sets the IF in monitoring mode.

[0078] In S6, the optical user terminal communication unit 140 of the controller 100 communicates with the optical user terminal 20-1A and instructs it to transmit an optical signal in a supported optical signal format.

[0079] In S7, the optical user terminal 20 transmits an optical signal to the optical signal multiplexer 10 in accordance with the instruction in S6.

[0080] In S8, the optical frame monitoring unit 13A of the optical signal multiplexer 10 receives the optical signal from the optical user terminal 20-1A and monitors the optical frames.

[0081] In S9, the optical signal monitoring unit 13 of the optical signal multiplexing device 10 transmits the monitoring result to the controller 100. The monitoring result includes, for example, information indicating which model number of the optical transceiver the monitored optical frame belongs to.

[0082] In S10, the optical signal compliance check unit 130 in the controller 100 checks whether the optical frame of the optical user terminal 20-1A complies with the contract conditions of the optical user terminal 20-1A.

[0083] In S11, the optical user terminal communication unit 140 of the controller 100 communicates with the optical user terminal 20 and instructs it to stop transmitting an optical signal.

[0084] In S12, the optical signal multiplexing communication unit 150 of the controller 100 communicates with the optical signal transmitting and receiving unit 12 of the optical signal multiplexing device 10 and instructs it to cancel the monitoring mode.

[0085] In S13 , the optical user terminal connection accepting unit 110 of the controller 100 transmits a connection response to the external system 200 .

[0086] (Hardware Configuration Example) The controller 100 (control device) described in this embodiment can be realized, for example, by causing a computer to execute a program. This computer may be a physical computer or a virtual machine on a cloud.

[0087] That is, the controller 100 can be realized by using hardware resources such as a CPU and memory built into a computer to execute a program corresponding to the processing performed by the controller 100. The program can be recorded on a computer-readable recording medium (such as a portable memory) and can be saved or distributed. The program can also be provided via a network such as the Internet or email.

[0088] Fig. 12 is a diagram showing an example of the hardware configuration of the computer. The computer in Fig. 12 includes a drive device 1000, an auxiliary storage device 1002, a memory device 1003, a CPU 1004, an interface device 1005, a display device 1006, an input device 1007, an output device 1008, and the like, all of which are interconnected by a bus BS. The computer may further include a GPU.

[0089] The program that realizes the processing on the computer is provided by a recording medium 1001, such as a CD-ROM or a memory card. When the recording medium 1001 storing the program is set in the drive device 1000, the program is installed from the recording medium 1001 to the auxiliary storage device 1002 via the drive device 1000. However, the program does not necessarily have to be installed from the recording medium 1001, but may be downloaded from another computer via a network. The auxiliary storage device 1002 stores the installed program as well as necessary files, data, etc.

[0090] The memory device 1003 reads and stores the program from the auxiliary storage device 1002 when an instruction to start the program is received. The CPU 1004 realizes functions related to the controller 100 in accordance with the program stored in the memory device 1003. The interface device 1005 is used as an interface for connecting to a network, etc. The display device 1006 displays a GUI (Graphical User Interface) or the like according to the program. The input device 1007 is composed of a keyboard, mouse, buttons, a touch panel, etc., and is used to input various operation instructions. The output device 1008 outputs the results of calculations.

[0091] As described above, the technology described in this embodiment makes it possible to check whether the optical frames of optical signals transmitted by optical user terminals are appropriate in an optical transmission system that enables multiple optical user terminals, each equipped with an optical transceiver, to be directly connected via optical wavelength paths. As a result, optical signals can be transmitted appropriately in the optical transmission system.

[0092] The following additional notes are provided regarding the above-described embodiments.

[0093] <Additional Notes> (Additional Item 1) An optical signal multiplexing device in an optical transmission system for connecting an optical user terminal equipped with an optical transceiver to another optical user terminal equipped with an optical transceiver by an optical wavelength path via an optical signal multiplexing device, the optical signal multiplexing device comprising: an optical frame monitoring unit that monitors optical frames of the optical user terminal, and an optical signal transmitting and receiving unit that transmits optical signals received from the optical user terminal to the optical frame monitoring unit. (Additional Item 2) The optical signal multiplexing device according to Additional Item 1, wherein the optical signal transmitting and receiving unit comprises: a distribution device that, in a monitoring mode, transmits optical signals received from the optical user terminal to the optical frame monitoring unit, or an optical branching device that transmits optical signals received from the optical user terminal to the optical frame monitoring unit and also transmits them to the other optical user terminal. (Additional Item 3) The optical signal multiplexing device according to Additional Item 1 or 2, comprising an optical frame monitoring unit for each type of optical transceiver. (Supplementary Item 4) A control device in an optical transmission system for connecting an optical user terminal equipped with an optical transceiver to another optical user terminal equipped with an optical transceiver by an optical wavelength path via an optical signal multiplexing device, comprising: a memory; and at least one processor connected to the memory, wherein the processor confirms whether or not an optical frame is appropriate as an optical frame for the optical user terminal based on a monitoring result of the optical frame in the optical signal by the optical signal multiplexing device that receives the optical signal. (Supplementary Item 5) The control device according to Supplementary Item 4, wherein the processor instructs the optical user terminal to stop transmitting the optical signal when it determines that the optical frame is not appropriate as an optical frame for the optical user terminal. (Supplementary Item 6) An optical transmission system comprising the optical signal multiplexing device according to any one of Supplementary Items 1 to 3, and the control device according to Supplementary Item 4 or 5.(Supplementary Item 7) A verification method executed by a control device in an optical transmission system for connecting an optical user terminal equipped with an optical transceiver to another optical user terminal equipped with an optical transceiver by an optical wavelength path via an optical signal multiplexer, the verification method comprising: verifying whether or not an optical frame is appropriate as an optical frame for the optical user terminal, based on a monitoring result of the optical signal transmitted from the optical user terminal by the optical signal multiplexer that receives the optical signal. (Supplementary Item 8) A non-transitory storage medium storing a program for causing a computer to function as an optical signal compliance verification unit in the control device according to Supplementary Item 4 or 5.

[0094] Although the present embodiment has been described above, the present invention is not limited to such a specific embodiment, and various modifications and changes are possible within the scope of the gist of the present invention described in the claims.

[0095] REFERENCE SIGNS LIST 1 Optical transmission device 2 User terminal 3 Transponder 4 Optical signal multiplexing unit 10 Optical signal multiplexing device 11 Controller communication unit 12 Optical signal transmitting and receiving unit 13 Optical frame monitoring unit 14 Optical signal multiplexing / demultiplexing unit 15 Optical signal transmitting and receiving unit 20 Optical user terminal 21 Controller communication unit 22 Electrical-optical signal conversion unit 23 Optical signal transmitting and receiving unit 100 Controller 110 Optical user terminal connection acceptance unit 120 Connection relationship confirmation unit 130 Optical signal compliance confirmation unit 140 Optical user terminal communication unit 150 Optical signal multiplexing communication unit 200 External system 1000 Drive device 1001 Recording medium 1002 Auxiliary storage device 1003 Memory device 1004 CPU 1005 Interface device 1006 Display device 1007 Input device 1008 Output device

Claims

1. An optical signal multiplexing device in an optical transmission system for connecting an optical user terminal equipped with an optical transceiver to another optical user terminal equipped with an optical transceiver by an optical wavelength path via an optical signal multiplexing device, the optical signal multiplexing device comprising: an optical frame monitoring unit that monitors optical frames of the optical user terminal; and an optical signal transmitting / receiving unit that transmits optical signals received from the optical user terminal to the optical frame monitoring unit.

2. The optical signal multiplexing device according to claim 1, wherein the optical signal transmitting / receiving unit comprises: a distribution device that, in a monitoring mode, transmits an optical signal received from the optical user terminal to the optical frame monitoring unit; or an optical branching device that transmits an optical signal received from the optical user terminal to the optical frame monitoring unit and also transmits the optical signal toward the other optical user terminal.

3. The optical signal multiplexing device according to claim 1, further comprising an optical frame monitoring unit for each type of optical transceiver.

4. A control device in an optical transmission system for connecting an optical user terminal equipped with an optical transceiver to another optical user terminal equipped with an optical transceiver by an optical wavelength path via an optical signal multiplexing device, the control device comprising: an optical signal compliance confirmation unit that confirms, based on the monitoring results of the optical frames in an optical signal transmitted from the optical user terminal by the optical signal multiplexing device that receives the optical signal, whether the optical frame is appropriate as an optical frame for the optical user terminal.

5. The control device according to claim 4, wherein the optical signal compliance check unit instructs the optical user terminal to stop transmitting the optical signal when it determines that the optical frame is not appropriate as an optical frame for the optical user terminal.

6. An optical transmission system comprising an optical signal multiplexing device according to any one of claims 1 to 3 and a control device according to claim 4 or 5.

7. A confirmation method executed by a control device in an optical transmission system for connecting an optical user terminal equipped with an optical transceiver to another optical user terminal equipped with an optical transceiver by an optical wavelength path via an optical signal multiplexing device, the confirmation method comprising: confirming, based on a monitoring result of an optical frame in an optical signal by the optical signal multiplexing device receiving an optical signal transmitted from the optical user terminal, whether or not the optical frame is appropriate as an optical frame for the optical user terminal.

8. A program for causing a computer to function as an optical signal compliance confirmation unit in the control device according to claim 4 or 5.

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