WO2021131001A1

WO2021131001A1 - Optical communication device, optical communication system, and optical communication method

Info

Publication number: WO2021131001A1
Application number: PCT/JP2019/051305
Authority: WO
Inventors: 拓也金井; 淳一可児; 鈴木　裕生; 慎金子; 一暁本田
Original assignee: 日本電信電話株式会社
Priority date: 2019-12-26
Filing date: 2019-12-26
Publication date: 2021-07-01
Also published as: WO2021131083A1; WO2021131170A1

Abstract

An optical communication device according to the present invention is provided with an optical switch, a wavelength management control unit, and an optical switch control unit. The optical switch is connected with a plurality of transmission paths, and outputs an optical signal input from any of the transmission paths to another transmission path. The wavelength management control unit dynamically allocates, to a subscriber device, a wavelength according to a communication destination. The optical switch control unit controls the optical switch so as to output an optical signal input from a transmission path to a transmission path according to the communication destination specified through a combination of the subscriber device that transmitted the input optical signal and the wavelength of the input optical signal.

Description

Optical communication device, optical communication system and optical communication method

The present invention relates to an optical communication device, an optical communication system, and an optical communication method.

The number of users who use high-speed Internet through FTTH (Fiber To The Home) and mobile services continues to increase. The high-speed Internet has become an indispensable part of people's lives. On the other hand, in the backbone network that provides FTTH and mobile services, the network is independently constructed for each service. Therefore, it is inefficient in terms of operation. Therefore, an access network that accommodates a plurality of services in one device has been proposed (see, for example, Non-Patent Document 1). Furthermore, in order to realize an access network capable of accommodating multi-services, PON (Passive Optical Network) such as WDM-PON (Wavelength Division Multiplexing PON) and TDM-PON (Time Division Multiplexing PON) that use multiple wavelengths: Passive optical network) is standardized by ITU-T (International Telecommunication Union Telecommunication Standardization Sector) (see, for example, Non-Patent Document 2).

On the other hand, in the existing optical access system, the communication between the subscriber's device and the station building is connected to the higher-level core network. The device on the subscriber side is, for example, an ONU (Optical Network Unit). In addition, the connection to the core network is made via the termination device in the device on the station building side. The terminal device is, for example, an OLT (Optical Line Terminal). In this OLT, an optical signal is once converted into an electric signal, and user information, destination information is added to or deleted from the electric signal, routing processing, and the like are performed. Therefore, some delay occurs in communication. Further, when the amount of data increases, the OLT may store a signal in the buffer and perform priority control and the like. This further increases the delay. As the delay increases, the quality of optical service drops significantly. Therefore, it is important to reduce the delay as much as possible.

In order to improve the quality of optical services and provide various services via optical access networks, it is necessary to reduce the delay that occurs in OLT. Delay can be greatly reduced by using an optical switch or the like that can perform processing such as routing without converting an optical signal into an electric signal.

However, when applying routing using an optical switch to optical access, detailed information such as the destination and timing of data sent from the user is required. To obtain such information, convert the optical signal sent from the subscriber device into an electric signal, extract the information, set the optical path of the optical signal according to the extracted information, and further, the subscriber device. It is necessary to set the transmitter / receiver (wavelength, modulation method, etc.).

In view of the above circumstances, an object of the present invention is to provide an optical communication device, an optical communication system, and an optical communication method capable of relaying an optical signal according to a destination while reducing delay.

One aspect of the present invention is an optical switch that is connected to a plurality of transmission lines and outputs an optical signal input from one of the transmission lines to the other transmission line, and a subscriber device having a wavelength corresponding to the communication destination. A communication destination specified by a combination of a dynamically assigned wavelength management control unit, an optical signal input from the transmission line, the subscriber device that transmitted the input optical signal, and the wavelength of the input optical signal. It is an optical communication device including an optical switch control unit that controls the optical switch so as to output to the corresponding transmission line.

One aspect of the present invention is an optical communication system including a plurality of subscriber devices and the above-mentioned optical communication device, and the subscriber device transmits an optical signal having a wavelength assigned by the optical communication device. It is an optical communication system including an optical transmitter.

In one aspect of the present invention, a transfer step in which an optical switch connected to a plurality of transmission lines outputs an optical signal input from one of the transmission lines to the other transmission line and a wavelength management control unit are added. In the assignment step of dynamically assigning a wavelength according to the communication destination to the user device and the subscriber who transmitted the input optical signal to the optical switch control unit in the transfer step. It is an optical communication method including an optical switch control step for controlling the optical switch so as to output to the transmission line according to a communication destination specified by a combination of the device and the wavelength of the input optical signal.

According to the present invention, it is possible to relay an optical signal according to a destination while reducing delay.

It is a figure which shows the structural example of the optical communication system by embodiment of this invention. It is a figure which shows the example of the optical SW by an embodiment. It is a figure which shows the example of the optical SW by an embodiment. It is a figure which shows the example of the optical SW by an embodiment. It is a figure which shows the example of the optical SW by an embodiment. It is a figure which shows the example of the optical SW by an embodiment. It is a figure which shows the example of the routing before the wavelength change in the optical SW by an embodiment. It is a figure which shows the example of the routing after the wavelength change in the optical SW by an embodiment. It is a figure which shows the example of the optical SW by an embodiment. It is a figure which shows the example of the optical SW by an embodiment. It is a figure which shows the example of the optical SW by an embodiment. It is a figure which shows the configuration example of the optical access system by 1st Embodiment. It is a figure which shows the example of the SW connection table by the same embodiment. It is a figure which shows the example of the user wavelength table by the same embodiment. It is a figure which shows the example of the wavelength table between stations by the same embodiment. It is a figure which shows the configuration example of the subscriber apparatus by the same embodiment. It is a figure which shows the configuration example of the subscriber apparatus by the same embodiment. It is a flowchart which shows the initial setting process of the optical access system by the same embodiment. It is a figure which shows the configuration example of the optical access system by the same embodiment. It is a figure which shows the configuration example of the optical access system by the same embodiment. It is a figure which shows the configuration example of the optical access system by the same embodiment. It is a figure which shows the configuration example of the optical access system by the same embodiment. It is a figure which shows the configuration example of the optical access system by 2nd Embodiment. It is a figure which shows the configuration example of the optical access system by the same embodiment. It is a figure which shows the configuration example of the optical access system by the same embodiment. It is a figure which shows the configuration example of the optical access system by 3rd Embodiment. It is a figure which shows the configuration example of the optical access system by the same embodiment. It is a figure which shows the configuration example of the optical access system by the same embodiment. It is a figure which shows the configuration example of the optical access system by the 4th Embodiment. It is a figure which shows the configuration example of the optical access system by the same embodiment. It is a figure which shows the configuration example of the optical access system by the same embodiment. It is a figure which shows the configuration example of the optical access system by the same embodiment. It is a figure which shows the configuration example of the optical access system by 5th Embodiment. It is a figure which shows the configuration example of the optical access system by 6th Embodiment.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the plurality of drawings, the same parts are designated by the same reference numerals, and the description thereof will be omitted. In the present embodiment, the optical switch uses the wavelength of each optical signal as destination information to perform routing without converting the optical signal into an electric signal. In this embodiment, in response to a connection request (including destination information) from each subscriber device, the wavelength controller, the optical switch controller, and the management database that manages the connection information of all subscribers are linked. Assign each individual wavelength used by the subscriber device. At this time, the device for controlling the subscriber device is used to transmit setting information such as the wavelength to be used to each subscriber device. Communication is performed between the control device and the subscriber device using, for example, a control signal that is slower than the main signal, which is an optical signal between the subscriber devices, and can be superimposed on the main signal. This makes it possible to change settings and monitor without affecting the main signal. According to this embodiment, it is possible to reduce the delay caused by the termination device performing electrical processing.

FIG. 1 is a diagram showing a configuration example of the optical communication system 1 of the present embodiment. The optical communication system 1 has a plurality of optical SWs (switches) 10. Although only two optical SW10s are shown in the figure, the number of optical SW10s is arbitrary. The optical SW 10 is connected to the control unit 20. The optical SW10 communicates with another optical SW10 via the optical communication network 30. For the optical communication network 30, for example, a WDM (Wavelength Division Multiplexing) network including various topologies can be used. One or more subscriber devices 40 are connected to the optical SW10. The subscriber device 40 is connected to the optical SW10 by, for example, an optical access network such as PON (Passive Optical Network). The subscriber device 40 has an optical transceiver 41. The optical transceiver 41 is an example of the configuration of an optical transmitter and an optical receiver in the subscriber device. The optical transceiver 41 has an optical transmitter (Tx) 42 and an optical receiver (Rx) 43. The optical transceiver 41 is a tunable optical transceiver. As the optical transceiver 41, for example, a conventional optical transceiver with an AMCC (Auxiliary Management and Control Channel) function can be used.

The control unit 20 has an optical transceiver 21. The optical transceiver 21 is an example of the configuration of the optical transmission unit and the optical reception unit in the control unit 20. The optical transceiver 21 has an optical transmitter (Tx) 22 and an optical receiver (Rx) 23. The optical transceiver 21 is a tunable wavelength optical transceiver. The control unit 20 stores the wavelength management table. The wavelength management table is data indicating the wavelength assigned to each subscriber device 40. The control unit 20 uses the AMCC function to assign a wavelength used by the subscriber device 40 for communication.

In order to assign a wavelength according to the destination to the subscriber device 40, first, the optical transceiver 41 of the subscriber device 40 and the optical transceiver 21 of the control unit 20 communicate with each other using AMCC. The control unit 20 refers to the wavelength table and selects a wavelength to be assigned to the subscriber device 40 from among the available wavelengths according to the destination. The control unit 20 sets the selected wavelength in the subscriber device 40 by the control signal using AMCC. After that, the control unit 20 switches the optical SW 10 so as to perform routing according to the destination indicated by the wavelength of the optical signal transmitted from the subscriber device 40. As a result, the subscriber devices 40 facing each other are connected.

The optical SW10 is provided in, for example, an optical gateway (GW). An example of the optical SW10 provided in the optical GW will be described with reference to FIGS. 2 to 11.

FIG. 2 is a diagram showing a configuration example of the optical SW10a. The optical SW10a is connected to a plurality of transmission lines 50, and outputs an optical signal input from one of the transmission lines 50 to another transmission line 50. The transmission line 50 is, for example, an optical fiber. The optical SW10a has ports 11-1-1 to 11-1-P (P is an integer of 2 or more) and ports 11-2-1 to 11-2-Q (Q is an integer of 2 or more). If any of ports 11-1-1 to 11-1-P is not specified, or generically, it is described as port 11-1, and any of ports 11-2-1 to 11-2-Q is referred to. When not specified, or collectively, it is described as port 11-2. The transmission line 50 connected to the port 11-1 is referred to as a transmission line 50-1, and the transmission line 50 connected to the port 11-2 is referred to as a transmission line 50-2.

Each port 11-1 is connected to the subscriber device 40 via the transmission line 50-1. Each port 11-2 is connected to the subscriber device 40 via a transmission line 50-2. The subscriber device 40 is, for example, an ONU. The transmission line 50-2 may be connected to the optical communication network 30 which is an upper network. In this case, the direction of the subscriber device 40 connected via the transmission line 50-1 is the downward direction, and the direction of the upper network connected via the transmission line 50-2 is the upward direction. Further, the transmission line 50-2 may be provided with another optical communication device such as an optical SW10.

Ports 11-1-1, 11-1-2, 11-1-3, ... Are the subscriber devices 40 of the ground A via the transmission line 50-1, 40a-1, 40a-2, 40a-, respectively. 3, ... is connected. One of the ports 11-2 (port 11-2-1 in the figure) is connected to the wavelength management control unit 25 described later. Some ports 11-2-i, 11-2- (i + 1), 11-2- (i + 2), ... Are 40b-1 subscriber devices 40 to ground B via transmission lines 50-2, respectively. , 40b-2, 40b-3, ... (I is an integer of 2 or more). Some ports 11-2-j, 11-2- (j + 1), 11-2- (j + 2), ... Different from the port 11-2 connected to the subscriber device 40 of the ground B are transmission lines 50, respectively. It is connected to 40c-1, 40c-2, 40c-3, ..., Which are the subscriber devices 40 of the ground C, via -2 (j is an integer of 2 or more). The optical SW10a outputs the optical signal input from the port 11-1 to the port 11-2, and outputs the optical signal input from the port 11-2 to the port 11-1.

The optical SW10a is connected to the control unit 20. The control unit 20 includes a wavelength control control unit 25 and an optical SW control unit 26. The wavelength management control unit 25 receives a wavelength allocation request from the subscriber device 40 by an optical signal, dynamically assigns a wavelength according to the communication destination to the subscriber device 40 that has transmitted the request, and sets the assigned wavelength to light. A wavelength allocation process for notifying the subscriber device 40 by a signal is performed. For the optical signal transmitted and received between the wavelength management control unit 25 and the subscriber device 40, a management control signal superimposition method that does not depend on the communication protocol of the optical signal (main signal) between the subscriber devices 40 is used. For example, a protocol-free AMCC is used as an optical signal transmitted and received between the wavelength management control unit 25 and the subscriber device 40.

The optical SW control unit 26 controls the optical SW 10a so as to transmit and receive an optical signal between the subscriber device 40 and the wavelength management control unit 25 while the wavelength allocation process is being executed. After the wavelength allocation process, the optical SW control unit 26 uses the optical signal input from the transmission line 50 as a communication destination specified by a combination of the subscriber device 40 that transmitted the input optical signal and the wavelength of the input optical signal. The optical SW10a is controlled so as to output to the transmission line 50-2 according to the above.

Each transmission line 50-2 is provided with a monitoring circuit 60. In the figure, only one monitoring circuit 60 is shown. The monitoring circuit 60 is an example of a monitoring unit. The monitoring circuit 60 has a power splitter 61. The power splitter 61 branches the optical signal transmitted through the transmission line 50-2. The monitoring circuit 60 monitors the optical signal branched by the power splitter 61. The monitoring circuit 60 generates monitoring information based on the monitoring result and outputs the generated monitoring information. The monitoring information is information indicating the result of monitoring or information obtained from the result of monitoring. As the output destination of the monitoring information, for example, the control unit 20 can be mentioned. Further, during communication with another subscriber device 40, the power splitter 61 branches the control signal transmitted by the subscriber device 40, or superimposes the control signal on the signal between the subscriber devices 40 and transmits the signal. Can be done.

The wavelength management control unit 25 may perform a wavelength change process for instructing the subscriber device 40 that has performed the wavelength allocation process to change the wavelength. For example, the wavelength management control unit 25 identifies the subscriber device 40 to be changed in wavelength based on the monitoring information output from the monitoring circuit 60, and performs wavelength change processing on the specified subscriber device 40. The optical SW control unit 26 controls the optical SW 10a so that an optical signal is transmitted and received between the subscriber device 40 and the wavelength management control unit 25 during the wavelength change process. When the optical SW control unit 26 inputs an optical signal of the changed wavelength from the subscriber device 40 after the wavelength change processing, the optical SW control unit 26 outputs the input optical signal to the transmission line 50-2 according to the communication destination. Controls the optical SW10a. For example, the optical SW control unit 26 inputs an optical signal of the changed wavelength from the subscriber device 40 after the wavelength change processing, and uses the input optical signal as the source subscriber device 40 and the wavelength before the change. The optical SW10a is controlled so as to output to the transmission line 50-2 according to the communication destination in which the combination of the above is used. Alternatively, the optical SW control unit 26 controls the optical SW10a so as to output an optical signal transmitted from the source subscriber device 40 using the changed wavelength to a transmission line 50-2 different from that before the wavelength change. You may. In this case, the subscriber device 40 of the communication destination is different before and after the wavelength change processing. Further, the wavelength management control unit 25 may receive a wavelength change request from the subscriber device 40 during communication or after communication is completed, and may perform wavelength change processing on the requesting subscriber device 40. By the wavelength change processing, both the wavelength used for transmission and the wavelength used for reception by the subscriber device 40 may be changed, or either of them may be changed.

FIG. 3 is a diagram showing a configuration example of an optical SW10b having a folding circuit. In the figure, the same parts as those of the optical SW10a shown in FIG. 2 are designated by the same reference numerals, and the description thereof will be omitted. Further, in FIG. 3, the description of the control unit 20 is omitted. The optical SW10b is connected to the return transmission line 51. The return transmission line 51 is an optical fiber that inputs an optical signal output from port 11-2 to another port 11-2. As a result, the optical SW10b enables return communication.

FIG. 4 is a diagram showing a configuration example of an optical SW10c that performs uplink multicast. In the figure, the same parts as those of the optical SW10a shown in FIG. 2 are designated by the same reference numerals, and the description thereof will be omitted. Further, in FIG. 4, the description of the control unit 20 is omitted. The optical SW10c has a distribution unit 58 that distributes the optical signal output from the port 11-2 to a plurality of components, distributes the optical signals, and inputs the plurality of optical signals to different ports 11-1. The distribution unit 58 is an example of the first distribution unit. In FIG. 4, the optical SW10c inputs the optical signal output from the port 11-2 to the other port 11-2 via the return transmission line. The optical SW10c outputs this input optical signal to the port 11-1 to which the 1 × N power splitter 71 is connected. The optical signal output from port 11-1 is distributed by the power splitter 71 and input to a plurality of other ports 11-1. The optical SW10c outputs the optical signals input from the plurality of ports 11-1 to different ports 11-2, respectively. Two-way communication is also possible. The down light signal is routed in the opposite direction of the up direction.

FIG. 5 is a diagram showing a configuration example of an optical SW10d that performs downlink multicast. In the figure, the same parts as those of the optical SW10a shown in FIG. 2 are designated by the same reference numerals, and the description thereof will be omitted. Further, in FIG. 5, the description of the control unit 20 is omitted. The optical SW10d has a distribution unit 59 that distributes the optical signals output from the port 11-1 to a plurality of components, distributes the optical signals, and inputs the plurality of optical signals to different ports 11-2. The distribution unit 59 is an example of the second distribution unit. In FIG. 5, the optical SW10d inputs the optical signal output from the port 11-1 to the other port 11-1 via the return transmission line. The optical SW10d outputs this input optical signal to the port 11-2 to which the 1 × N power splitter 72 is connected. The optical signal output from port 11-2 is distributed by the power splitter 72 and input to a plurality of other ports 11-2. The optical SW10d outputs the optical signals input from the plurality of ports 11-2 to different ports 11-1.

FIG. 6 is a diagram showing a configuration example of an optical SW10e that performs WDM transmission. In the figure, the same parts as those of the optical SW10a shown in FIG. 2 are designated by the same reference numerals, and the description thereof will be omitted. The optical SW10e is connected to one or more WDM devices 80. The WDM device 80 is an example of a demultiplexing device. The WDM device 80 combines optical signals of different wavelengths output from each of the plurality of ports 11-2 and outputs them to the multiplexing communication transmission line 90. Further, the WDM device 80 demultiplexes the optical signal received via the multiplex communication transmission line 90 according to the wavelength, and inputs the demultiplexed optical signal to each of the plurality of ports 11-2. In this way, the WDM device 80 combines the wave-binding device that combines optical signals of different wavelengths output from the plurality of ports 11-2 of the optical SW10e and outputs them to the multiplex communication transmission line 90, and the multiplex communication transmission line 90. It has a function as a demultiplexer that demultiplexes the optical signal received via the wavelength according to the wavelength and inputs each of the demultiplexed optical signals to a plurality of ports 11-2 having different optical SW10e. The optical SW10e that performs WDM transmission may connect the return transmission line 51 shown in FIG. 3 to the port 11-2 that is not connected to the WDM device 80.

The multiplex communication transmission line 90 is provided with a monitoring circuit 65. The monitoring circuit 65 includes a power splitter 66 and

WDM devices

67 and 68. The power splitter 66 branches an optical signal transmitted through the multiplex communication transmission line 90. The WDM device 67 demultiplexes the upstream optical signal branched by the power splitter 66. The WDM device 68 demultiplexes the downlink optical signal branched by the power splitter 66. The monitoring circuit 65 monitors the optical signal demultiplexed by the WDM device 67 and the WDM device 68. The monitoring circuit 65 generates monitoring information based on the monitoring result and outputs the generated monitoring information. The monitoring information is information indicating the result of monitoring or information obtained from the result of monitoring. For example, when the monitoring circuit 65 detects an abnormality in the communication status between the subscriber devices 40 by monitoring the optical signal, it identifies that the abnormality in the communication status has occurred and the subscriber device 40 in which the abnormality in the communication status has occurred. Outputs monitoring information with information to be set. As the output destination of the monitoring information, for example, the control unit 20 can be mentioned.

The wavelength management control unit 25 may perform a wavelength change process for instructing the subscriber device 40 that has performed the wavelength allocation process to change the wavelength. For example, the wavelength management control unit 25 identifies the subscriber device 40 to be changed in wavelength based on the monitoring information output from the monitoring circuit 65, and performs wavelength change processing on the specified subscriber device 40. The optical SW control unit 26 controls the optical SW 10e so that an optical signal is transmitted and received between the subscriber device 40 and the wavelength management control unit 25 during the wavelength change process. When the optical SW control unit 26 inputs an optical signal of the changed wavelength from the subscriber device 40 after the wavelength change processing, the optical SW control unit 26 illuminates so that the input optical signal is output from the port 11-2 according to the communication destination. Control SW10e. Further, the wavelength management control unit 25 may receive a wavelength change request from the subscriber device 40 during communication or after communication is completed, and may perform wavelength change processing on the requesting subscriber device 40.

An example of wavelength change in the optical SW10e will be described with reference to FIGS. 7 and 8. FIG. 7 is a diagram showing an example of routing in the optical SW10e before changing the wavelength. The optical SW10e is connected to 40a-1, 40a-2, 40a-3, ..., Which are the subscriber devices 40 of the ground A. The WDM device 80 connected to the ground B is referred to as a WDM device 80b, and the WDM device 80 connected to the ground C is referred to as a WDM device 80c. _{The WDM device 80b transmits and receives optical signals having wavelengths λ 1} to λ ₁₀ to and from the optical SW 10e, and the WDM device 80c transmits and receives optical signals having wavelengths λ ₁₁ to λ ₂₀ to and from the optical SW 10e.

In FIG. 7, before the wavelength is changed, the optical SW10e has different ports 11 for _{the optical signal of wavelength λ 1} _{input from the subscriber device 40a-1 and the optical signal of wavelength λ 2} input from the subscriber device 40a-2. -2 outputs to the WDM device 80b. The subscriber device 40a-2 transmits a wavelength change request to the wavelength management control unit 25 by a control signal during or after the communication is completed. Upon receiving the wavelength change request from the subscriber device 40a-2, the wavelength management control unit 25 performs a wavelength change process instructing the _{subscriber device 40a-2 to change to the wavelength λ 10.} Light SW control unit 26 controls the light SW10e to output the optical signal of the wavelength lambda ₁₀ received from the subscriber unit 40a-2, from port 11-2 corresponding to the wavelength lambda ₁₀ to the WDM device 80b. The wavelength management control unit 25 may further change the wavelength used for reception by the subscriber device 40a-2.

Further, the optical SW control unit 26 illuminates the optical SW control unit 26 so as to output the optical signal transmitted from the transmitting subscriber device 40 using the changed wavelength to the WDM device 80 different from that before the wavelength change after the wavelength change processing. SW10e may be controlled. FIG. 8 is a diagram showing an example of routing after the wavelength change in the optical SW10e when the output destination WDM device 80 is changed. Before changing the wavelength, as shown in FIG. 7, the subscriber device 40a-1 communicates using the _{wavelength λ 1} , and the subscriber device 40a-2 _{communicates using the wavelength λ 2} or the wavelength λ _10. The subscriber device 40a-2 transmits a wavelength change request to the wavelength management control unit 25 by a control signal during or after the communication is completed. When the wavelength management control unit 25 receives the wavelength change request from the subscriber device 40a-2, the wavelength management control unit 25 instructs the subscriber device 40a-2 to change to the _{wavelength λ 11 in order to communicate with the subscriber device 40 of the ground C.} Perform processing. Light SW control unit 26 controls the light SW10e to output the optical signal of the wavelength lambda ₁₁ received from the subscriber unit 40a-2, from port 11-2 corresponding to the wavelength lambda ₁₁ to the WDM device 80c. The wavelength management control unit 25 may further change the wavelength used for reception by the subscriber device 40a-2.

In the above, the wavelength change process performed when the subscriber device 40 requests the wavelength change has been described, but the same applies to the wavelength change process performed based on the monitoring information.

An optical SW that performs WDM transmission and multicast will be described with reference to FIGS. 9 to 11. FIG. 9 is a diagram showing a configuration example of an optical SW10f that performs WDM transmission and multicast in the uplink direction. In FIG. 9, the optical SW10f performs uplink multicast by a single wavelength. As shown in FIG. 9, the optical SW10f has a distribution unit 58 similar to that in FIG. In FIG. 9, multicast is performed to ground B and ground C. The optical SW10f outputs an optical signal input from the port 11-1 connected to the subscriber device 40-1 from the port 11-2 to which the return transmission line is connected, and outputs an optical signal transmitted through the return transmission line. Input from another port 11-2. The optical SW10f outputs this input optical signal from the port 11-1 to which the 1 × N power splitter 71 is connected. The optical SW10f inputs the optical signal distributed by the 1 × N power splitter 71 from a plurality of ports 11-1, and one of the input optical signals is input to the port 11-2 connected to the ground B, and the other 1 Two optical signals are output to port 11-2 connected to ground C.

FIG. 10 is a diagram showing a case where the optical SW10f performs upbound multicast to a plurality of grounds by a plurality of wavelengths. By providing one or more 1 × M power splitters 55 in the transmission line 50-1, a plurality of subscriber devices 40 can be connected to the transmission line 50-1 connected to one port 11-1. .. In FIG. 10, subscriber devices 40a-1-1, 40a-1-2, ... Are connected to one transmission line 50-1 as a plurality of subscriber devices 40a-1. The subscriber devices 40a-1-1, 40a-1-2, ... Use different wavelengths. Here, the subscriber device 40a-1-1 _{transmits an optical signal of wavelength λ 1} , and the subscriber device 40a-1-2 transmits an optical signal of _{wavelength λ 2.} The optical SW10f is a port 11 that transmits an optical signal obtained by combining an optical signal having _{a wavelength λ 1} transmitted by the subscriber device 40a-1-1 _{and an optical signal having a wavelength λ 2} transmitted by the subscriber device 40a-1-2. Enter from -1. The optical SW10f outputs the input optical signal from the port 11-2 to which the return transmission line is connected, and inputs the optical signal transmitted through the return transmission line from the other port 11-2. The optical SW10f outputs this input optical signal from the port 11-1 to which the 1 × N power splitter 71 is connected. The optical SW10f inputs the optical signal distributed by the 1 × N power splitter 71 from the plurality of ports 11-1.

The optical SW10f transmits the optical signal distributed by the power splitter 71 to _{the port 11-2 corresponding to the wavelength λ 1} and the port 11-2 corresponding to the wavelength λ _{2 among the ports 11-2 connected to the WDM device 80b.} Output to. Further, the optical SW10f transmits the optical signal distributed by the power splitter 71 to _{the port 11-2 corresponding to the wavelength λ 1} and the port 11 corresponding to the wavelength λ _{2 among the ports 11-2 connected to the WDM device 80c.} Output to -2. WDM device 80b outputs to the multiplex communication transmission path 90 by passing the optical signal of the wavelength lambda ₁ to filter an input optical signal from the port corresponding to the wavelength lambda _1, input from the port corresponding to the wavelength lambda ₂ The optical signal is filtered to _{pass an optical signal having a wavelength of λ 2} and output to the multiplexing communication transmission line 90. Port Similarly, WDM device 80c is the output to the multiplex communication transmission line 90 is passed through the optical signal of the wavelength lambda ₁ to filter an input optical signal from the port corresponding to the wavelength lambda _1, corresponding to the wavelength lambda ₂ The optical signal input from is filtered _{, passed through an optical signal having a wavelength of λ 2} , and output to the multiplexing communication transmission line 90.

FIG. 11 is a diagram showing a configuration example of an optical SW 10 g that performs WDM transmission and downlink multicast. The optical SW 10g has a distribution unit 59 similar to that in FIG. Further, the optical SW10f shown in FIGS. 9 and 10 and the optical SW10g shown in FIG. 11 may have the same monitoring circuit 65 as in FIG. The wavelength management control unit 25 can perform wavelength change processing on the subscriber device 40 for which the monitoring circuit 65 has detected an abnormality in the communication status in the same manner as described above.

In each of the embodiments shown below, an example of an optical access system using an optical SW having the above-mentioned functions will be described.

(First Embodiment)
FIG. 12 is a diagram showing a configuration example of the optical access system 100. The optical access system 100 includes an optical gateway (GW) 200 and an operating system (OPS) 400. The subscriber device 40 is communicably connected to an upper network such as the optical communication network 30 shown in FIG. 1 by the optical access system 100.

The subscriber device 40 is a device on the optical subscriber side. The subscriber device 40 is connected to the optical GW 200 via a transmission line 501. The transmission line 501 is, for example, an optical fiber. The optical GW 200 is a device in the communication station building. The subscriber device 40 represented by the reference numeral N1 and the optical GW 200 are connected via, for example, a transmission line 501 or a power splitter 502. The network configuration for connecting the subscriber device 40 to the optical GW 200 may be various network topologies such as PtoP (point-to-point), PON configuration, and bus type. For example, the transmission line 501 may have a power splitter 502 or the like, and a plurality of subscriber devices 40 may be connected to one transmission line 501. The optical GW 200 is connected to another station building, a core network, or the like via a transmission line 511 and a transmission line 512. The transmission line 511 and the transmission line 512 are, for example, optical fibers. The transmission line 511 transmits an uplink signal, and the transmission line 512 transmits a downlink signal. The transmission line 511 and the transmission line 512 are examples of multiplex communication transmission lines for transmitting wavelength-multiplexed optical signals. The connection from the optical GW 200 indicated by the reference numeral N2 to another station building or the core network is connected by, for example, an optical fiber transmission line 511 or a transmission line 512, so that the connection between the ground and the ground becomes a full mesh. ing. In the present embodiment, the optical GW 200 is installed in the station building of the ground A, and is installed in the optical communication device set in the station building of the ground B and the station building of the ground C via the optical communication network 30 or the like. The case where the optical communication device is connected to the optical communication device will be described as an example. The optical communication device of the ground B and the ground C to which the optical GW 200 is connected may be the optical GW 200.

The subscriber device 40 is connected to the optical GW 200 via the transmission line 501. The subscriber device 40 has an optical transceiver 41. The optical transceiver 41 is a tunable optical transceiver. The optical transceiver 41 is, for example, an optical transceiver that mutually converts an optical signal and an electric signal. The subscriber device 40 can select its own wavelength and set it in the optical transceiver 41 according to the transmission / reception destination. The subscriber device 40 sets the wavelength to be used in the optical transceiver 41 according to the instruction received from the optical GW 200. The M subscriber devices (M is an integer of 1 or more) connected to the optical GW 200 are referred to as subscriber devices 40-1 to 40-M.

The optical GW 200 includes an optical SW210, a wavelength duplexer 220, a control device 230, a duplexer 241 and a duplexer 242, a branch portion 250, and a monitoring device 260. The branch portion 250 and the monitoring device 260 are examples of the monitoring unit.

The optical SW210 has a plurality of input / output ports (hereinafter, referred to as "ports"), and connects two or more ports. The optical SW210 can freely switch the optical path between the ports. A port that inputs / outputs an uplink signal is referred to as an uplink port, and a port that inputs / outputs a downlink signal is referred to as a downlink port. Each port of the optical SW210 is connected to a transmission line.

The wavelength combiner / demultiplexer 220 performs upper and lower multiplex separation that separates an uplink signal and a downlink signal according to wavelength. The wavelength combiner / demultiplexer 220 inputs the upstream optical signal transmitted by the subscriber device 40 from the transmission line 501 and outputs the upstream optical signal to the optical SW210 via the transmission line 521. Further, the wavelength combiner / demultiplexer 220 inputs the downlink optical signal output by the optical SW210 from the transmission line 522 and outputs the downlink optical signal to the subscriber device 40 via the transmission line 501.

The control device 230 is connected to the uplink port and the downlink port to which the subscriber device 40 is not connected among the ports of the optical SW210. The uplink port of the optical SW210 is connected to the transmission side port of the control device 230 by the transmission line 531. The downlink port of the optical SW210 is connected to the port on the transmitting side of the control device 230 by the transmission line 533. The control device 230 includes a wavelength demultiplexer 231 and an optical receiver (Rx) 232 for each wavelength channel, and a tunable transmitter 233. The wavelength duplexer 231 is, for example, an AWG (Arrayed Waveguide Gratings). The wavelength demultiplexer 231 demultiplexes the light input to the receiving port via the transmission line 540 for each wavelength. The wavelength demultiplexer 231 outputs the demultiplexed light to the optical receiver 232 that receives the optical signal of the wavelength of the light. The tunable transmitter 233 has a tunable laser diode (LD) that generates light of a variable wavelength. The tunable transmitter 233 uses the light generated by the tunable laser diode to transmit an optical signal having a variable wavelength. The tunable transmitter 233 outputs an optical signal using the generated light from the port on the transmitting side to the transmission line 533.

The combiner 241 combines the upstream optical signals of different wavelengths output from each of the plurality of transmission lines 541 by the optical SW210 and outputs them to the transmission line 511 connected to the other ground. The demultiplexer 242 inputs an optical signal transmitted from any other ground to the transmission line 512, and demultiplexes the input downlink optical signal according to the wavelength. The demultiplexer 242 inputs the demultiplexed downlink optical signal to the optical SW210 via a plurality of transmission lines 542 connected to the uplink port corresponding to the wavelength of the optical signal.

The branch portion 250 is provided in the transmission line 511 and the transmission line 512. The branch 250 has

power splitters

251 and 252. The power splitter 251 branches the upstream optical signal transmitted through the transmission line 511 and inputs the upstream optical signal to the optical SW210 via the transmission line 551. The power splitter 252 branches the downlink optical signal transmitted through the transmission line 512 and inputs the downlink optical signal to the optical SW210 via the transmission line 552.

The monitoring device 260 has a wavelength demultiplexer 261 and an optical receiver (Rx) 262 for each wavelength. The wavelength demultiplexer 261 is connected to the optical SW210 via a transmission line 560. The optical SW210 outputs an optical signal input from a port connected to the transmission line 541 or the transmission line 542 to the port connected to the transmission line 560. As a result, the wavelength demultiplexer 261 receives the optical signal branched by the branch portion 250. The wavelength demultiplexer 261 demultiplexes the input optical signal for each wavelength. The wavelength demultiplexer 261 outputs each demultiplexed light to an optical receiver 262 that receives an optical signal of the wavelength of the light. The monitoring device 260 monitors the state of communication transmitted and received by the subscriber device 40 by the optical signal received by the optical receiver 262.

The OPS 300 has an optical GW control unit 301 and a management DB 350. The optical GW control unit 301 is connected to the optical GW 200. The optical GW control unit 301 includes a wavelength control unit 310 and an optical SW control unit 320. The wavelength control unit 310 stores information indicating the wavelength of light used by each user (or each service). The wavelength control unit 310 dynamically assigns the wavelength used by each user with reference to this information. The wavelength control unit 310 may be installed in a building different from the optical GW 200 and may be connected to the optical SW 210 or the optical SW control unit 320 via a network. By sharing each connection information, the wavelength control unit 310 manages and controls information on which user is connected to which port of the optical SW210 and which wavelength is used in real time.

Further, the optical GW control unit 301 is connected to the management database (DB) 350. The optical GW control unit 301 exchanges information on the user and the wavelength used with the management DB 350. The management DB 350 stores the wavelength used and the destination information of each user. The destination is represented by, for example, ground A, ground B, or the like. The management DB 350 manages information of all users connected to the optical access system 100.

FIG. 13 is a diagram showing an example of a SW connection table. The SW connection table shows the connection destination of each port of the optical SW210. That is, the port to which the optical signal is input / output can be used as information for identifying the subscriber device 40, the control device 230, the branch portion 250, the monitoring device 260, the ground, etc. of the source or destination of the optical signal. Is.

The wavelength table includes a user wavelength table and an inter-station wavelength table.
FIG. 14 is a diagram showing an example of a user wavelength table. The user wavelength table shows the wavelengths used by each user for transmission, the wavelengths used for reception, the empty wavelengths not used for transmission / reception, and the wavelengths that cannot be used due to a failure.

FIG. 15 is a diagram showing an example of an inter-station wavelength table. In the inter-station wavelength table, one ground has a wavelength used for communication with each other ground, an empty wavelength not used for communication with each other ground, and a failure in communication with each other ground. Indicates a wavelength that cannot be used because it is medium.

Subsequently, a configuration example of the subscriber device 40 will be described with reference to FIGS. 16 and 17. FIG. 16 is a configuration diagram of a two-core type subscriber device 401. Subscriber device 401 has an optical transceiver 411. The optical transceiver 411 includes a tunable light source 451, a tunable filter 452, and a receiver 453. The tunable light source 451 is an example of an optical transmitter, and the tunable filter 452 and the receiver 453 are an example of an optical receiver. The tunable light source 451 outputs light having a set wavelength. The wavelength set in the tunable light source 451 is variable. The tunable filter 452 inputs an optical signal from the transmission line 501 and passes light of a set wavelength through the receiver 453. The wavelength set in the tunable filter 452 is variable. The receiver 453 receives the optical signal passed through the tunable filter 452. The tunable light source 451 can output a main signal (or a signal obtained by superimposing a control signal on the main signal) by, for example, a direct modulation method. Alternatively, the tunable light source 451 further has an external modulator, and the external modulator can be used to output a main signal (or a signal obtained by superimposing a control signal on the main signal). The subscriber device 401 on the receiving side may be configured not to use the tunable filter 452 depending on the configuration of the optical GW, the multiplexing method, and the like.

FIG. 17 is a configuration diagram of a single-core type subscriber device 402. The subscriber device 402 has an optical transceiver 412. The optical transceiver 412 shown in FIG. 17 differs from the optical transceiver 411 shown in FIG. 16 in that it further includes a WDM filter 454. The WDM filter 454 separates the uplink signal and the downlink signal according to the wavelength. The WDM filter 454 outputs the light generated by the tunable light source 451 to the transmission line 501, and outputs the optical signal input from the transmission line 501 to the tunable filter 452. The tunable light source 451 can output a main signal (or a signal obtained by superimposing a control signal on the main signal) by, for example, a direct modulation method. Alternatively, the subscriber device 402, like the subscriber device 401, may further have an external modulator and output a main signal (or a signal obtained by superimposing a control signal on the main signal) using the external modulator. it can. The subscriber device 402 on the receiving side may be configured not to use the tunable filter 452 depending on the configuration of the optical GW, the multiplexing method, and the like.

Here, the operation when the subscriber device 40 is newly connected will be described. FIG. 18 is a flowchart showing an initial setting process of the optical access system 100 when a new subscriber device is connected. The operation of the optical access system 100 when the subscriber device 40-1 is newly connected to the optical GW 200 will be described with reference to FIGS. 12 and 18. It is assumed that the control device 230 has confirmed in advance which port of the optical SW210 each port of the wavelength demultiplexer 261 (AWG) of the control device 230 is connected to.

First, a user application is made before connecting the new subscriber device 40-1. For example, by applying for a user, it is possible to perform communication between the ground A and the ground B. Based on the user application, the business operator registers user information, initial destination information, and the like in the management DB 350 of the OPS 300 (step S1). The user information is, for example, information that can obtain a wavelength that can be used by the optical transceiver 41. The OPS300 refers to the SW connection table and assigns the port of the optical SW210 to which the subscriber device 40-1 is connected from among the empty ports of the optical SW210. Here, an uplink port and a downlink port are assigned. The OPS300 registers information indicating that the assigned port is connected to the subscriber device 40-1 in the SW connection table (step S2). The optical SW control unit 320 of the OPS300 controls the optical SW210 so as to transmit and receive an optical signal between the port assigned to the subscriber device 40-1 and the port to which the control device 230 is connected.

When a new subscriber device 40-1 is connected, the subscriber device 40-1 performs initialization processing and transmits a connection request (register request) by an optical signal (step S3). The subscriber device 40-1 automatically performs the initialization process before or immediately after the connection. The wavelength combiner / demultiplexer 220 inputs a connection request from the transmission line 501 and outputs the connection request to the optical SW210 via the transmission line 521. The optical SW210 transmits the connection request input from the port connected to the subscriber device 40-1 to the output port to which the control device 230 is connected. The control device 230 inputs a connection request from the reception port via the transmission line 531. The control device 230 analyzes the input optical signal and confirms whether there is a problem with the initial set wavelength and the optical power (step S4).

The control device 230 transmits a restart or initialization instruction to the subscriber device 40-1 when there is a problem with the wavelength or the optical power. After restarting or initial setting, the process returns to step S3, and the subscriber device 40-1 transmits the connection request again.

The control device 230 analyzes the optical signal received from the subscriber device 40-1, and when it is confirmed that there is no problem, outputs a connection request to the optical GW control unit 301. The optical GW control unit 301 registers the information of the subscriber device 40-1 in the management DB 350. The connection request includes information on the connection source, information on the connection destination, the type of signal to be transmitted, and the like. As the connection source information, for example, address information such as a MAC (Medium Access Control) address is used. For the information of the connection destination, for example, the address information of the destination is used. As the type of signal to be transmitted, for example, a service, a modulation method, or the like is used. The wavelength control unit 310 registers the connection source information in the management DB 350 based on the information. As a result, the user wavelength table is set to identify the user who uses the subscriber device 40-1 and to indicate that the wavelength that can be used by the subscriber device 40-1 is free. Further, the wavelength control unit 310 calculates the optimum route between the subscriber device 40-1 and the communication destination, such as between the ground A and the ground B, by comparing with the connection information stored in the management DB 350. The wavelength control unit 310 searches for a vacancy indicated by the inter-station wavelength table according to the calculated path. The wavelength control unit 310 selects a wavelength to be used by the subscriber device 40-1 from the available wavelengths, and transmits information on the selected wavelength to the control device 230 (step S5).

The other subscriber device 40, which is the communication destination of the subscriber device 40-1, is described as the communication destination subscriber device 40. In this case, the wavelength control unit 310 has a transmission wavelength which is a wavelength used by the subscriber device 40-1 to transmit an optical signal to the communication destination subscriber device 40, and the subscriber device 40-1 is a communication destination subscriber. A reception wavelength, which is a wavelength used for receiving an optical signal from the device 40, is selected. The wavelength control unit 310 transmits the selected transmission wavelength and reception wavelength to the control device 230 as the wavelength used by the subscriber device 40-1. When the subscriber device 40-1 only transmits to the communication destination subscriber device 40, the wavelength control unit 310 does not have to select the reception wavelength. Further, when the subscriber device 40-1 only receives from the communication destination subscriber device 40, the wavelength control unit 310 does not have to select the transmission wavelength.

The control device 230 transmits wavelength information as follows. The tunable transmitter 233 of the control device 230 transmits a wavelength instruction set with information on the wavelength selected by the wavelength control unit 310 by an optical signal having a wavelength representing the subscriber device 40-1. The optical SW210 outputs an optical signal input from a port connected to the tunable transmitter 233 to a transmission line 522 connected to the subscriber device 40-1. The wavelength combiner / demultiplexer 220 incidents an optical signal input from the optical SW 210 via the transmission line 522 into the transmission line 501. The subscriber device 40-1 receives the optical signal transmitted through the transmission line 501. The subscriber device 40-1 sets the oscillation wavelength of the optical transceiver 41 according to the wavelength instruction indicated by the received optical signal (step S6). That is, the subscriber device 40-1 sets the oscillation wavelength of the optical transceiver 41 (tunable wavelength light source 451) so that the optical signal is transmitted by the transmission wavelength set in the wavelength indication. When the reception wavelength is set in the wavelength instruction, the subscriber device 40-1 sets the optical transceiver 41 (tunable filter 452) so as to receive the wavelength signal of the reception wavelength.

The optical transceiver 41 of the subscriber device 40-1 transmits a notification signal notifying that the wavelength has been set by the optical signal of the instructed wavelength. The notification signal is transmitted to the control device 230 in the same manner as the request signal. Based on the received notification signal, the control device 230 confirms whether the specified wavelength is set correctly, whether the output power is sufficient, and the like (step S7). If it is determined that there is no problem as a result of the confirmation, the control device 230 transmits a permission notification indicating permission to start communication to the subscriber device 40-1 by an optical signal. The permission notification is transmitted to the subscriber device 40-1 as well as the wavelength indication.

The optical SW control unit 320 transmits the connection information of the optimum port in the optical SW 210 to the optical SW 210 according to the transmission destination of the subscriber device 40-1. Based on the connection information, the optical SW 210 sets the uplink port and the downlink port of the subscriber device 40-1 according to the instruction from the optical SW control unit 320 (step S8).

Further, the optical access system 100 controls the timing so that the route switching in the optical SW210 is performed after the permission for starting communication is transmitted from the control device 230 to the subscriber device 40-1. For example, it is assumed that the time required for switching the route of the optical SW210 is known in advance. In this case, the control device 230 actually communicates after the subscriber device 40-1 receives the permission to start communication for the time required to actually switch the route after the optical SW 210 receives the route switching instruction. Wait until the start of communication, and then instruct the start of communication. After the start of communication, the monitoring device 260 of the GW 200 confirms the confirmation of the communication status between the opposite subscriber devices (step S9). The monitoring device 260 notifies the OPS 300 of the confirmation result. If the confirmation is NG, the OPS 300 performs a cause isolation procedure.

Further, the connection request transmitted by the subscriber device 40-1 and the control signal transmitted by the control device 230 to the subscriber device 40-1 are optical signals slower than the main signal. As the control signal, for example, a protocol-free control signal (control method) represented by AMCC can be used.

Further, the OPS 400 communicates to the communication destination subscriber device 40 the transmission wavelength of the subscriber device 40-1 as the reception wavelength of the communication destination subscriber device 40 and the reception wavelength of the subscriber device 40-1. It is instructed to use it as a transmission wavelength of the first subscriber device 40. For example, in the optical GW control unit 301 that controls the optical GW 200 in which the communication destination subscriber device 40 is housed, the wavelength control unit 310 sets the wavelength for reception and the wavelength for transmission of the communication destination subscriber device 40. Instruct the control device 230 to transmit. The communication destination subscriber device 40 receives a wavelength instruction from the control device 230 by a control signal, and sets a reception wavelength and a transmission wavelength in the optical transceiver 41 according to the received wavelength instruction. That is, when the transmission wavelength is set in the wavelength instruction, the communication destination subscriber device 40 sets the oscillation wavelength of the optical transceiver 41 (wavelength variable light source 451) so as to transmit the optical signal according to the transmission wavelength. .. When the reception wavelength is set in the wavelength instruction, the communication destination subscriber device 40 sets the optical transceiver 41 (tunable filter 452) so as to receive the wavelength signal of the reception wavelength.

Even if the optical access system 100 does not perform the user application in step S1 and transmits / receives information to be registered in the management DB 350 by the user application between the new subscriber device 40-1 and the optical GW control unit 301. Good. As a result, the subscriber device 40-1 can communicate with another subscriber device 40 without making a user application. Information is transmitted / received between the subscriber device 40-1 and the optical GW control unit 301 via the control device 230, for example, using AMCC.

In the above, the operation when a new subscriber device is connected has been explained. Next, a normal communication operation after the new subscriber device is connected will be described by taking the case where the subscriber device 40-2 of FIG. 12 communicates as an example.

First, the uplink optical signal output by the subscriber device 40-2, which describes the uplink communication, is sent to the optical GW 200 via the transmission line 501. The wavelength combiner / demultiplexer 220 of the optical GW 200 separates the input optical signal into an upstream optical signal and a downstream optical signal according to the wavelength. The upstream optical signal demultiplexed by the wavelength combiner / demultiplexer 220 is input to the optical SW210 via the transmission line 521. The optical SW210 connects the port into which the upstream optical signal is input from the wavelength duplexer 220 to another port corresponding to the destination specified by the wavelength assigned to the subscriber device 40-2, and transmits the optical signal. Output. The uplink signal output from the optical SW210 is combined with an optical signal of a different wavelength transmitted by another subscriber device 40 in the combiner 241 and is combined with another station building via one transmission line 511. It is transmitted to (for example, ground B). The combiner 241 combines wavelength channels for each station building such as ground B and ground C, respectively. By separating the transmission line 511 between the ground B and the transmission line 511 between the ground C, it is possible to use the same wavelength between the ground B and the ground C.

Next, the downlink communication will be explained. The downlink is communication from the grounds B and C in the direction of the subscriber device 40. The downlink optical signal is sent to the optical GW 200 via one transmission line 512. The demultiplexer 242 of the optical GW 200 demultiplexes the downlink optical signal transmitted through the transmission line 512 according to the wavelength. The demultiplexer 242 inputs the demultiplexed light to the downlink port corresponding to the wavelength of the demultiplexed light via the transmission line 542, respectively. The optical SW210 outputs an optical signal by connecting a port to which a downlink optical signal is input from the demultiplexer 242 to another port according to the wavelength. The wavelength combiner / demultiplexer 220 separates an optical signal input from the optical SW210 via a transmission line 522 into an upstream optical signal and a downstream optical signal according to the wavelength. The downlink optical signal demultiplexed by the wavelength combiner / demultiplexer 220 is input to the subscriber device 40-2 via the transmission line 501. The wavelength channels transmitted from the optical GW 200 to each station building (ground B, C, etc.) are assumed to be the same wavelength band, but different wavelength bands may be used for each station building.

The monitoring device 260 of the optical GW 200 receives the light branched by the branch portion 250. The light branched by the branch portion 250 is an optical signal transmitted and received by each subscriber device 40. The monitoring device 260 monitors the signals transmitted and received by each subscriber device 40 by monitoring the received optical signal. When the monitoring device 260 detects an abnormality such as a wavelength shift, a decrease in output, or a communication abnormality by monitoring, the monitoring device 260 transmits an abnormality detection signal to the optical GW control unit 301. The optical SW control unit 320 of the optical GW control unit 301 controls the optical SW 210 so as to reconnect the target subscriber device 40 to the control device 230. Then, the optical GW control unit 301 performs a new wavelength allocation process different from the wavelength used when the abnormality is detected, as in the case of newly connecting the subscriber device 40. As a result, when the optical SW210 inputs the optical signal of the changed wavelength from the subscriber device 40, the optical SW210 connects the input optical signal to the port specified by the subscriber device 40 by the wavelength before the change.

Although the optical GW 200 shown in FIG. 12 performs wavelength division multiplexing, it is not necessary to perform wavelength division multiplexing as shown in FIGS. 19 and 20. FIG. 19 is a diagram showing a configuration example of the optical access system 101. The optical access system 101 shown in FIG. 19 differs from the optical access system 100 shown in FIG. 12 in that the GW 201 is provided instead of the GW 200. The difference between the GW 201 and the GW 200 is that the GW 201 includes a wavelength duplexer 243 and a branch 250a instead of the duplexer 241 and the demultiplexer 242 and the branch 250a. The GW 201 is connected to a communication device of another station building on the ground by a transmission line 503. One transmission line 503 transmits an uplink signal and a downlink signal to any of the grounds.

The wavelength combiner / demultiplexer 243 separates the input optical signal into an upstream optical signal and a downstream optical signal according to the wavelength. The wavelength combiner / demultiplexer 243 separates the upstream optical signal input from the optical SW210 via the transmission line 543-1 and transmits it to another ground or higher network via the transmission line 503. Further, the wavelength combiner / demultiplexer 243 separates the downlink optical signal input from another ground via the transmission line 503 and outputs it to the optical SW210 via the transmission line 543-2.

The branch portion 250a is provided in the transmission line 503. The branch portion 250a has a power splitter 251a. The power splitter 251a branches the upstream and downstream optical signals transmitted through the transmission line 503. The power splitter 251a inputs the branched upstream signal to the port of the optical SW210 via the transmission line 551a, and inputs the branched downstream signal to the port of the optical SW210 via the transmission line 551b. The optical SW210 outputs an optical signal input from the port connected to the transmission line 551a and an optical signal input from the port connected to the transmission line 551b from the port connected to the transmission line 560. As a result, the wavelength demultiplexer 261 of the monitoring device 260 receives the optical signal branched by the branch portion 250a.

FIG. 20 is a diagram showing a configuration example of the optical access system 102. The optical access system 102 shown in FIG. 20 differs from the optical access system 101 shown in FIG. 19 in that it includes an optical GW 202 instead of the optical GW 201. The difference between the optical GW 202 and the optical GW 201 is that the optical GW 202 is provided with a wavelength duplexer 244, a wavelength duplexer 245, and a branching portion 250b instead of the wavelength duplexer 243 and the branching portion 250a.

The wavelength combiner / demultiplexer 244 separates an upstream optical signal and a downstream optical signal according to the wavelength. The wavelength combiner / demultiplexer 244 inputs the upstream optical signal input from the optical SW210 via the transmission line 544 to the wavelength combiner / demultiplexer 245 via the transmission line 545. The wavelength combiner / demultiplexer 244 inputs the downlink optical signal input from the wavelength combiner / demultiplexer 245 via the transmission line 546 to the optical SW210 via the transmission line 544.

The wavelength combiner / demultiplexer 245 separates an upstream optical signal and a downstream optical signal according to the wavelength. The wavelength combiner demultiplexer 245 transmits an upstream optical signal input from the wavelength combiner demultiplexer 245 via the transmission line 545 to another ground or an upper network via the transmission line 503. Further, the wavelength combiner / demultiplexer 245 inputs the downlink optical signal received via the transmission line 503 to the wavelength combiner / demultiplexer 244 via the transmission line 546.

The branch portion 250b has a power splitter 251b and a power splitter 252b. The power splitter 251b branches the upstream optical signal transmitted through the transmission line 545. The power splitter 251b inputs the branched upstream signal to the port of the optical SW210 via the transmission line 551b. The power splitter 252b branches the downlink optical signal transmitted through the transmission line 546. The power splitter 252b inputs the branched downlink signal to the port of the optical SW210 via the transmission line 552b. The optical SW210 outputs an optical signal input from the port connected to the transmission line 551b and an optical signal input from the port connected to the transmission line 552b from the port connected to the transmission line 560. As a result, the wavelength demultiplexer 261 of the monitoring device 260 receives the optical signal branched by the branch portion 250b.

The monitoring device 260 described above has a receiver configuration including a wavelength demultiplexer 261 and an optical receiver 262 for each wavelength. The monitoring device may have a tunable optical receiver instead of this receiver configuration. Further, the transmitter / receiver of the control device may have a transmitter whose wavelength is not tunable, or may have a receiver configuration which does not have a wavelength demultiplexer. An example of such a configuration will be described with reference to FIG.

FIG. 21 is a diagram showing a configuration example of the optical access system 103. The optical access system 103 shown in FIG. 21 differs from the optical access system 100 shown in FIG. 12 in that it includes an optical GW 203 instead of the optical GW 200. The difference between the optical GW 203 and the optical GW 200 is that the optical GW 203 is provided with the control device 235 and the monitoring device 265 instead of the control device 230 and the monitoring device 260. The control device 235 has an optical receiver 236 and an optical transmitter 237 that is not tunable. The monitoring device 265 includes a tunable optical receiver 266.

Further, the monitoring device may be connected via an optical SW different from the above optical SW. An example of such a configuration will be described with reference to FIG. FIG. 22 is a diagram showing a configuration example of the optical access system 104. The optical access system 104 shown in FIG. 22 differs from the optical access system 103 shown in FIG. 21 in that it includes an optical GW 204 instead of the optical GW 203. The difference between the optical GW 204 and the optical GW 203 is that the optical SW 211 is further provided and the monitoring device 265 is connected to the optical SW 211.

The upstream optical signal separated from the transmission line 511 by the power splitter 251 of the branch portion 250 is input to the optical SW211 via the transmission line 555, and the downstream optical signal separated from the transmission line 512 by the power splitter 252 is transmitted through the transmission line 555. It is input to the optical SW211 via 555. The optical SW211 is, for example, a small optical SW. The number of ports of the optical SW211 is 1 on the monitoring device 260 side and 2M on the side where the monitored optical signal is input. 2M is twice the number M of the subscriber device 40 connected to the optical GW 204. Instead of using the small optical SW, monitoring devices may be prepared for the number of connected grounds to monitor all signals transmitted to and received from the grounds for each ground.

(Second embodiment)
In this embodiment, communication is performed between a plurality of subscriber devices connected to the same optical GW by using a return transmission line. Hereinafter, the differences from the first embodiment will be mainly described.

FIG. 23 is a diagram showing a configuration example of the optical access system 105. The optical access system 105 shown in FIG. 23 differs from the optical access system 103 shown in FIG. 21 in that the optical GW 205 is provided instead of the optical GW 203. The difference between the optical GW 205 and the optical GW 203 is that the optical GW 205 is further provided with a combiner 247 and a demultiplexer 248 corresponding to the ground A on which the optical GW 205 is installed. The combiner 247 and the demultiplexer 248 are connected by a transmission line 547. The transmission line 547 is a folded transmission line.

Similar to the combiner 241, the combiner 247 combines the upstream optical signals of different wavelengths output from each of the plurality of transmission lines 541 by the optical SW210 and outputs them to the transmission line 547. Similar to the demultiplexer 242, the demultiplexer 248 demultiplexes the downlink optical signal input from the transmission line 547 according to the wavelength. The demultiplexer 248 inputs the demultiplexed downlink optical signal to the optical SW210 via a plurality of transmission lines 542 connected to the downlink port corresponding to the wavelength of the optical signal. Further, the transmission line 547 is provided with a branch portion 250.

In the first embodiment, the subscriber device connected to the ground A is connected to the port for connecting to the ground B and the ground C via the optical SW. In the present embodiment, another set that is the same as the combination of the combiner 241 and the demultiplexer 242 connected to the ground B or the ground C is added. This added set is a combiner 247 and a demultiplexer 248. Then, the output port of the added duplexer 247 and the input port of the added demultiplexer 248 are connected by a transmission line 547. With this configuration, the signal output by the subscriber device 40 can be input to the optical SW210 again. As a result, the optical GW 205 folds back the optical signal output by a certain subscriber device 40 and re-enters the optical SW210 as a downlink signal. By connecting this folded signal to another subscriber device 40 in the optical SW 210, it is possible to perform loopback communication, that is, communication between the subscriber devices 40 connected to the same optical GW 205.

For example, a state in which the subscriber device 40-2 and the subscriber device 40-M are communicating with each other will be described. Each of the K (K is an integer of 2 or more) uplink ports corresponding to the ground A of the optical SW210 is connected to the combiner 247 by a transmission line 541, and each of the K downlink ports corresponding to the ground A of the optical SW210 It is assumed that the transmission line 542 is connected to the demultiplexer 248. Then, it is assumed that the kth (k is an integer of 1 or more and K or less) of the K downlink ports and uplink ports corresponding to the ground A corresponds to the wavelength λ _k . _{The upstream optical signal of wavelength λ 1} output from the subscriber device 40-2 is connected to the first uplink port corresponding to the ground A. The input optical signal is folded back by the transmission line 547 and is input again to the optical SW210 as a downlink optical signal from the first downlink port corresponding to the ground A. The optical SW control unit 320 sets a path in the optical SW 210 so that the signal is transmitted to the subscriber device 40-M according to the wavelength. _{Similarly, the upstream optical signal of wavelength λ k} output from the subscriber device 40-M is connected to the k-th uplink port corresponding to the ground A. The input optical signal is folded back by the transmission line 547 and is input again to the optical SW210 as a downlink optical signal from the k-th downlink port corresponding to the ground A. The optical SW control unit 320 sets a path in the optical SW 210 so that the signal is transmitted to the subscriber device 40-2 according to the wavelength. As a result, communication is performed between the subscriber device 40-2 and the subscriber device 40-M.

Other configurations of this embodiment will be described with reference to FIGS. 24 and 25. FIG. 24 is a diagram showing a configuration example of the optical access system 106. The optical access system 106 shown in FIG. 24 differs from the optical access system 105 shown in FIG. 23 in that it includes an optical GW 206 instead of the optical GW 205. The difference between the optical GW 206 and the optical GW 205 is that the optical GW 206 is not provided with a duplexer 247 and a demultiplexer 248, and the optical SW210 is directly connected between the upstream port and the downstream port for ground A by a transmission line 548 without wavelength division multiplexing. As a result, the signal is folded back.

FIG. 25 is a diagram showing a configuration example of the optical access system 107. The difference between the optical access system 107 shown in FIG. 25 and the optical access system 105 shown in FIG. 23 is that the optical GW 207 is provided instead of the optical GW 205. The optical GW 207 differs from the optical GW 205 in that it includes a power splitter 270 instead of the duplexer 248. The power splitter 270 branches the downlink optical signal input from the combiner 247 via the transmission line 547 into a plurality of branches, and inputs the downlink optical signal to the optical SW210 via the plurality of transmission lines 542.

A power splitter may be provided after the demultiplexer 248 of the optical GW 205 in FIG. 23. The power splitter splits the optical signal demultiplexed by the demultiplexer 248 into a plurality of light signals and inputs them to different ports of the optical SW210. By doing so, multicast communication of return communication becomes possible.

Although the difference from the optical access system 103 has been described above, it is also possible to apply the difference to the

optical access systems

100, 101, and 102.

(Third Embodiment)
The optical access system of this embodiment performs multicast communication. In this embodiment, the differences from the first and second embodiments will be mainly described.

First, multicast for downlink communication will be described with reference to FIG. FIG. 26 is a diagram showing a configuration example of the optical access system 108. The optical access system 108 shown in FIG. 26 differs from the optical access system 107 shown in FIG. 25 in that it includes an optical GW 208 instead of the optical GW 207. The optical GW 208 differs from the optical GW 207 in that it further includes a transmission line 549 connecting the return port of the optical SW210.

The case of multicasting the downlink optical signal transmitted from the ground C will be described. The optical SW control unit 320 controls the port for inputting the downlink optical signal from the ground C so as to be connected to the return port to which the transmission line 549 is connected according to the wavelength. As a result, the downlink optical signal from the ground C is transmitted through the transmission line 549 and is input to the optical SW210 again as the uplink signal of the ground A. Further, the optical SW control unit 320 controls to connect the downlink optical signal input from the return port to the uplink signal port of the ground A as in the second embodiment. As a result, the optical signal input to the optical SW210 after turning back the transmission line 549 is output to the port connected to the combiner 247. The combiner 247 combines the optical signals output from the optical SW210 by each of the plurality of transmission lines 541 and outputs the optical signals to the transmission line 547. The optical signal output to the transmission line 547 is branched into a plurality of signals in the power splitter 270. The power splitter 270 inputs a plurality of branched optical signals to the optical SW210 as a downlink signal of the ground A via the plurality of transmission lines 542. The optical SW 210 outputs an optical signal input from each transmission line 542 to a port connected to the subscriber device 40 according to the wavelength. This enables multicasting of downlink signals.

Subsequently, the multicast of uplink communication will be described with reference to FIG. 27. FIG. 27 is a diagram showing a configuration example of the optical access system 109. The optical access system 109 shown in FIG. 27 differs from the optical access system 103 shown in FIG. 21 in that it includes an optical GW 209 instead of the optical GW 203. The optical GW 209 differs from the optical GW 203 in that it further includes a transmission line 570 that connects a return port to the optical SW210 and a power splitter 271 for multicast. The power splitter 271 is connected to the optical SW210 via a transmission line 572 and a plurality of transmission lines 573.

The case of multicasting the upstream optical signal transmitted from the ground A will be described. The optical SW control unit 320 controls the port for inputting the upstream optical signal from the ground A so as to be connected to the return port to which the transmission line 570 is connected according to the wavelength. As a result, the upstream optical signal from the ground A is transmitted through the transmission line 570 and is input to the optical SW210 again. Further, the optical SW control unit 320 controls to output the optical signal input from the return port to the port connected to the power splitter 271. As a result, the optical signal input to the optical SW210 by folding back the transmission line 570 is output to the transmission line 572. The optical signal output to the transmission line 572 is branched into a plurality of signals in the power splitter 271. The power splitter 271 inputs a plurality of branched optical signals to the optical SW210 as an uplink signal via the plurality of transmission lines 573. The optical SW210 outputs an optical signal input from each transmission line 573 to a port connected to ground B or ground C, depending on the wavelength. This enables multicasting of uplink signals.

Subsequently, with reference to FIG. 28, a configuration in which point-to-multipoint communication including uplink communication is performed while performing downlink communication multicast will be described. FIG. 28 is a diagram showing a configuration example of the optical access system 110. The optical access system 110 shown in FIG. 28 differs from the optical access system 103 shown in FIG. 21 in that it includes an optical GW 2010 instead of the optical GW 203. The optical GW 2010 differs from the optical GW 203 in that it further includes a

transmission line

574, 575 that connects a return port to the optical SW210, and a

power splitter

272, 273. The power splitter 272 is connected to the optical SW210 via a transmission line 581 and a plurality of transmission lines 582. The power splitter 273 is connected to the optical SW210 via the plurality of transmission lines 583 and the transmission line 584.

The case of multicasting the downlink optical signal transmitted from the ground C will be described. The optical SW control unit 320 controls the port for inputting the downlink optical signal from the ground C so as to be connected to the return port to which the transmission line 574 is connected according to the wavelength. As a result, the downlink optical signal from the ground C is transmitted through the transmission line 574 and is input to the optical SW210 again as the uplink signal of the ground A. Further, the optical SW control unit 320 controls to output the downlink optical signal input from the return port to the port to which the power splitter 272 is connected. As a result, the optical signal input to the optical SW210 by folding back the transmission line 574 is output to the transmission line 581. The optical signal output to the transmission line 581 is branched into a plurality of signals in the power splitter 272. The power splitter 272 inputs a plurality of branched optical signals to the optical SW210 as a downlink signal via the plurality of transmission lines 582. The optical SW 210 outputs an optical signal input from each transmission line 582 to a port connected to the subscriber device 40 according to the wavelength. This enables multicasting of downlink signals.

The case where the upstream optical signal transmitted from the ground A is transmitted to the ground C will be described. The optical SW control unit 320 controls the port for inputting the upstream optical signal from the ground A so as to be connected to the port to which the power splitter 273 is connected according to the wavelength. As a result, the upstream optical signal from the ground A is output to the transmission line 583. The optical signals output to each of the plurality of transmission lines 583 are combined in the power splitter 273. The power splitter 273 inputs the combined optical signal to the optical SW210 via the transmission line 584. The optical SW210 controls to connect the optical signal input from the transmission line 584 to the return port to which the transmission line 575 is connected. As a result, the optical signal is transmitted through the transmission line 575 and is input to the optical SW210 again. The optical SW210 outputs the optical signal input from the transmission line 575 to the combiner 241 connected to the ground C according to the wavelength.

As described above, by providing two sets of configurations using a power splitter for multicast, not only downlink multicast communication but also point-to-multipoint communication including uplink communication becomes possible.

(Fourth Embodiment)
In the present embodiment, communication is performed without separating the uplink signal and the downlink signal. Hereinafter, the differences from the above-described embodiments will be mainly described.

FIG. 29 is a diagram showing a configuration example of the optical access system 111. The difference between the optical access system 111 shown in FIG. 29 and the optical access system 105 shown in FIG. 23 is that the optical GW 2011 is provided instead of the optical GW 205. The difference between the optical GW 2011 and the optical GW 205 is that it does not have a wavelength duplexer 220, and instead of the combiner 241 and the duplexer 242 and the branch 250, the wavelength duplexer 249 and the branch 253 And a point further provided with a wavelength combiner / demultiplexer 238.

The wavelength combiner / demultiplexer 249 is connected to the optical SW210 by a plurality of transmission lines 585. The wavelength combiner / demultiplexer 249 combines the upstream optical signals of different wavelengths output from each of the plurality of transmission lines 585 by the optical SW210 and outputs them to the transmission line 504 connected to any other ground. Further, the wavelength combiner / demultiplexer 249 demultiplexes the downlink optical signal input from another ground via the transmission line 504 according to the wavelength. The wavelength combiner demultiplexer 249 inputs the demultiplexed downlink optical signal to the optical SW210 via a plurality of transmission lines 585 connected to the uplink port corresponding to the wavelength of the optical signal.

The branch portion 253 has a power splitter 254. The power splitter 254 branches an upstream optical signal and a downstream optical signal transmitted through the transmission line 504. The power splitter 254 inputs the branched upstream optical signal to the port of the optical SW210 via the transmission line 586, and inputs the branched downstream optical signal to the port of the optical SW210 via the transmission line 587. The optical SW210 outputs an optical signal input from a port connected to the transmission line 586 or the transmission line 587 to the port connected to the transmission line 560.

The wavelength combiner / demultiplexer 238 is connected to the optical SW210 by a transmission line 534, and is connected to the control device 235 by a transmission line 531 and a transmission line 533. The wavelength combiner / demultiplexer 238 separates the input optical signal into an upstream optical signal and a downstream optical signal according to the wavelength. The wavelength combiner / demultiplexer 238 outputs an upstream optical signal input from the optical SW 210 via the transmission line 534 to the control device 235 via the transmission line 531. The wavelength combiner / demultiplexer 238 outputs a downlink optical signal input from the control device 235 via the transmission line 533 to the optical SW210 via the transmission line 534.

As described above, the optical GW211 does not have a wavelength duplexer between the optical SW210 and the subscriber device 40, and has a configuration that does not separate the uplink signal and the downlink signal. As a result, the number of ports used for the optical SW210 can be greatly reduced, and the amount of information to be managed can be greatly reduced. Further, as shown in FIG. 30, the portion that separates the signal to the monitoring device 265 may be configured as shown in FIG.

FIG. 30 is a diagram showing a configuration example of the optical access system 112 of the present embodiment. The optical GW 2012 of the optical access system 112 shown in FIG. 30 includes a branch portion 255 instead of the branch portion 253 included in the optical GW 2011 shown in FIG. 29. The branch portion 255 includes a wavelength combiner / demultiplexer 256, a wavelength combiner / demultiplexer 257, a power splitter 258, and a power splitter 259.

The wavelength combiner / demultiplexer 256 separates the input optical signal into an upstream optical signal and a downstream optical signal depending on the wavelength. The wavelength combiner / demultiplexer 256 outputs the upstream optical signal input from the wavelength combiner / demultiplexer 249 to the wavelength combiner / demultiplexer 257 via the transmission line 588. The wavelength combiner / demultiplexer 256 outputs a downlink optical signal input from the wavelength combiner / demultiplexer 257 via a transmission line 589 to the wavelength combiner / demultiplexer 249.

The wavelength combiner / demultiplexer 257 separates an upstream optical signal and a downstream optical signal according to the wavelength. The wavelength combiner / demultiplexer 257 outputs an upstream optical signal input from the wavelength combiner / demultiplexer 256 via the transmission line 588 to the transmission line 504. The wavelength combiner / demultiplexer 257 inputs a downlink optical signal received from another ground via the transmission line 504 to the wavelength combiner / demultiplexer 256 via the transmission line 589.

The power splitter 258 branches the upstream optical signal transmitted through the transmission line 588 and inputs it to the port of the optical SW210 via the transmission line 586. The power splitter 259 branches the downlink optical signal transmitted through the transmission line 589 and inputs it to the port of the optical SW210 via the transmission line 587. The optical SW210 outputs an optical signal input from a port connected to the transmission line 586 or the transmission line 587 to the port connected to the transmission line 560.

The optical GW 2011 shown in FIG. 29 performs wavelength division multiplexing, but as shown in FIG. 31, a configuration in which signals to be transmitted to each station building (ground B or ground C) are transmitted through individual transmission lines without wavelength division multiplexing. May be.

FIG. 31 is a diagram showing a configuration example of the optical access system 113. The optical access system 113 shown in FIG. 31 differs from the optical access system 101 shown in FIG. 19 in that it includes an optical GW 2013 instead of the optical GW 201. The difference between the optical GW 2013 and the optical GW 201 is that it does not have the wavelength duplexer 220 and the wavelength duplexer 243, and instead of the control device 230 and the monitoring device 260, the control device 235 shown in FIG. 29. , A wavelength combiner / demultiplexer 238 and a monitoring device 265 are provided. The port of the optical SW210 connected to the transmission line 503 outputs an upstream optical signal and inputs a downlink optical signal.

Further, in the optical GW 2013, the branch portion 250a may be configured as shown in FIG. 32. FIG. 32 is a diagram showing a configuration example of the optical access system 114. The optical GW 2014 of the optical access system 114 shown in FIG. 32 has the same configuration as the branch portion 255 shown in FIG. 30 instead of the branch portion 250a included in the optical GW 2013 shown in FIG. 31.

(Fifth Embodiment)
This embodiment enables control over a subscriber device during communication. Hereinafter, the differences from the above-described embodiments will be mainly described.

FIG. 33 is a diagram showing a configuration example of the optical access system 115. The optical access system 115 shown in FIG. 33 differs from the optical access system 104 shown in FIG. 22 in that it includes an optical GW 2015 instead of the optical GW 204. The difference between the optical GW 2015 and the optical GW 204 is that the monitoring control device 267 is connected to the optical SW211 instead of the monitoring device 265.

The monitoring control device 267 includes a tunable receiver 268 and a tunable transmitter 269. The monitoring control device 267 can receive an optical signal of an arbitrary wavelength by the tunable wavelength receiver 268, and can transmit an optical signal of an arbitrary wavelength by the tunable wavelength transmitter 269. Further, the optical GW 2015 includes a control device 235. As described in the first embodiment, when the subscriber device 40 is connected, the optical GW 2015 performs connection processing (registration, wavelength allocation, etc.) of the subscriber device 40 by using the control device 235, and is usually performed. Start communication.

Here, consider a state in which the subscriber device 40-1 is connected to the ground B. Since the subscriber device 40-1 is in a state of performing normal communication, it cannot communicate with the control device 235. Therefore, by providing the monitoring control device 267 connected to the optical SW211 which is a small optical SW, not only the communication status of the subscriber device 40-1 can be monitored, but also various setting instructions of the subscriber device 40-1 can be instructed. It will be possible. That is, the optical signal separated by the power splitter 251 is output to the optical SW211 via the transmission line 555. The optical SW211 outputs the received optical signal to the monitoring control device 267. The monitoring control device 267 monitors the wavelength tunable receiver 268 with the optical signal received from the optical SW211 and further receives the control signal superimposed on the received optical signal. The tunable transmitter 269 of the monitoring control device 267 transmits a control signal to the subscriber device 40 as an optical signal. The optical SW211 outputs a signal received from the tunable transmitter 269 to a port corresponding to the wavelength. The power splitter 251 combines the control signal received from the optical SW 211 via the transmission line 556 with the optical signal transmitted through the transmission line 512. With this configuration, even when the subscriber device 40-1 is performing normal communication, the subscriber device 40-1 receives a request for changing the connection destination, etc., and transmits a control signal to the subscriber device 40-1. It is possible to switch wavelengths and the like.

For the communication of the control signal between the monitoring control device 267 and each subscriber device 40, a control signal which is slower than the optical main signal between the subscriber devices and can be superimposed on the main signal is used. For example, techniques such as AMCC can be used.

(Sixth Embodiment)
In this embodiment, the optical signal extracted from the optical SW is subjected to electrical processing. Hereinafter, the differences from the above-described embodiments will be mainly described.

FIG. 34 is a diagram showing a configuration example of the optical access system 116. The optical access system 116 shown in FIG. 34 differs from the optical access system 105 shown in FIG. 23 in that it includes an optical GW 2016 instead of the optical GW 202. The difference between the optical GW 2016 and the optical GW 202 is that the processing function unit 600 is connected.

The processing function unit 600 converts an optical signal into an electric signal, performs electrical processing, and then converts it into an optical signal again and outputs it. In this electric processing, a signal processing function by electricity and a function such as OLT are implemented. The signal processing function is, for example, code error correction such as FEC (forward error correction).

When the optical access system 116 is a PON (Passive Optical Network), the subscriber device 40-M is connected to the optical GW 2016 via a transmission line 501 such as an optical fiber and a power splitter 507. The upstream optical signal of the subscriber device 40-M is connected to the processing function unit 600 via the optical SW210. The OLT function is implemented in the processing function unit 600. The processing function unit 600 processes the electric stage. A plurality of subscriber devices 40 are connected to the OLT. The processing function unit 600, which is equipped with the OLT function, collectively manages the subscriber devices 40. The processing function unit 600 collects the signals transmitted from each subscriber device 40 into one and outputs the signals to the optical SW210. The processing function unit 600 has a tunable wavelength transmitter / receiver. The processing function unit 600 sets the wavelength to be transmitted and received according to the instruction from the control device 230.

The power splitter 507 between the subscriber device 40 and the optical GW 2016 may be a wavelength duplexer. For example, when the optical access system 116 is WDM-PON, a wavelength demultiplexer is used between the subscriber device 40 and the optical GW 2016.

The superimposition of the AMCC signal on the main signal will be explained. In the optical region, the same wavelength is used for the AMCC signal and the main signal. The main signal is a signal such as CPRI (Common Public Radio Interface) such as an OK (On-off keying) signal of 10 Gb / s (Gigabit per second). The AMCC signal is transmitted, for example, by superimposing a 1 MHz carrier wave on the main signal, and conveys information by intensity modulation. Such a low-speed AMCC signal is superimposed on the main signal, and the AMCC signal thus superimposed is separable from the main signal.

In the electrical domain, different frequencies are used for the AMCC signal and the main signal. The AMCC signal has a narrower band than the main signal. For example, a power combiner synthesizes a 10 GHz electric main signal and a 1 MHz electric AMCC signal, and a transmitter converts this combined signal into an optical signal to generate a main signal on which the AMCC signal is superimposed. .. The carrier frequency may be another frequency such as 500 kHz that does not overlap with the main signal of electricity, and another modulation method such as phase modulation may be used as the modulation method.

The

control device

230, 235, the

monitoring device

260, 265, the monitoring control device 267, the wavelength control unit 310, and the optical SW control unit 320 described above include a CPU (Central Processing Unit), a memory, an auxiliary storage device, and the like connected by a bus. In addition, some or all of the above-mentioned functions may be realized by executing the program. Note that some or all of the functions of the

control device

230, 235, the

monitoring device

260, 265, the monitoring control device 267, the wavelength control unit 310, and the optical SW control unit 320 are ASIC (Application Specific Integrated Circuit) or PLD (Programmable). It may be realized by using hardware such as Logic Device) or FPGA (Field Programmable Gate Array). The programs of the

control device

230, 235, the

monitoring device

260, 265, the monitoring control device 267, the wavelength control unit 310, and the optical SW control unit 320 may be recorded on a computer-readable recording medium. The computer-readable recording medium is, for example, a storage device such as a magneto-optical disk, a portable medium such as a ROM or a CD-ROM, or a hard disk built in a computer system. The program may be transmitted over a telecommunication line.

Further, the wavelength control unit 310 and the optical SW control unit 320 may be mounted by using one information processing device, or may be mounted by using a plurality of information processing devices that are communicably connected via a network. You may.

Although the embodiments of the present invention have been described in detail with reference to the drawings, the specific configuration is not limited to these embodiments, and includes designs and the like within a range that does not deviate from the gist of the present invention.

1 ... Optical communication system,
10, 10a, 10b, 10c, 10d, 10e, 10f, 10g, 210, 211 ... Optical switch,
11-1, 11-1-1 to 11-1-P, 11-2, 11-2-1 to 11-2-Q ... Port,
20 ... Control unit,
21, 41, 411, 412 ... Optical transceiver,
22, 42, 237 ... Optical transmitter,
23, 43, 232, 236 ... Optical receiver,
25 ... Wavelength control control unit,
26, 320 ... Optical SW control unit,
30 ... Optical communication network,
40, 40-1-40-M ... Subscriber device,
50, 50-1, 50-2, 51, 501, 503, 504, 511, 512, 521, 522, 531, 533, 534, 540, 541, 542, 543-1, 543-2, 544, 545, 546, 547, 548, 549, 551, 551a, 552, 552b, 555, 560, 561, 562, 563, 570, 571, 571, 573, 574, 575, 581, 582, 583, 584, 585, 586, 587, 588, 589 ... Transmission line,
58, 59 ... Distribution section,
60, 65 ... Monitoring circuit,
55, 61, 66, 71, 72, 251, 251a, 251b, 252, 252b, 254, 258, 259, 270, 271, 272, 273, 502, 507 ... Power Splitter,
67, 68, 80, 80a, 80b ... WDM device,
90 ... Multiplex communication transmission line,
100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116 ... Optical access system,
200, 201, 202, 203, 204, 205, 206, 207, 208, 209, 2010, 2011, 2012, 2013, 2014, 2015, 2016 ... Optical gateway,
220, 238, 243, 244, 245, 249, 256, 257 ... Wavelength duplexer,
230 ... Control device,
231 and 261 ... Wavelength demultiplexer,
233, 269 ... Tunable transmitter,
235 ... Control device,
241 and 247 ... Combiner,
242, 248 ... Demultiplexer,
250, 250a, 250b, 253, 255 ... Branch,
260, 265 ... Monitoring device,
262 ... Optical receiver,
262 ... Optical receiver,
266 ... Tunable optical receiver,
267 ... Monitoring and control device,
268 ... Tunable wavelength receiver,
300 ... Operation system,
301 ... Optical GW control unit,
310 ... Wavelength control unit,
350 ... Management database,
452 ... Tunable wavelength filter,
453 ... Receiver,
454 ... WDM filter,
600 ... Processing function unit

Claims

An optical switch that is connected to a plurality of transmission lines and outputs an optical signal input from one of the transmission lines to the other transmission line.
A wavelength management control unit that dynamically assigns wavelengths to subscriber devices according to the communication destination,
The optical signal input from the transmission line is output to the transmission line according to the communication destination specified by the combination of the subscriber device that transmitted the input optical signal and the wavelength of the input optical signal. An optical switch control unit that controls an optical switch,
An optical communication device equipped with.
The wavelength management control unit receives a request for wavelength allocation by an optical signal, dynamically assigns a wavelength according to a communication destination to a subscriber device that has transmitted the request, and subscribes the assigned wavelength by an optical signal. Performs wavelength allocation processing to notify the device
The optical switch control unit controls the optical switch so as to transmit and receive an optical signal between the subscriber device and the wavelength management control unit while the wavelength allocation process is being executed.
The optical communication device according to claim 1.
The optical signal transmitted and received between the wavelength management control unit and the subscriber device is slower than the main signal which is an optical signal between the subscriber devices.
The optical communication device according to claim 2.
The optical switch has a plurality of first ports and a plurality of second ports connected to different transmission lines, and outputs an optical signal input from the first port to the second port. The optical signal input from the second port is output to the first port.
The optical communication device according to any one of claims 1 to 3.
The optical switch is connected to a transmission line that inputs an optical signal output from the second port to another second port.
The optical communication device according to claim 4.
The optical switch has a first distribution unit that distributes an optical signal output by the second port into a plurality of parts and inputs the plurality of distributed optical signals to different first ports, and an output from the first port. It is connected to one or both of a second distribution unit that distributes the divided optical signals into a plurality of the distributed optical signals and inputs the distributed optical signals to different second ports.
The optical communication device according to claim 4.
A monitoring unit for monitoring an optical signal transmitted through the transmission line is further provided.
The optical communication device according to any one of claims 1 to 6.
The wavelength management control unit performs a wavelength change process for instructing the subscriber device to change the wavelength.
The optical switch control unit controls the optical switch so that an optical signal is transmitted and received between the subscriber device and the wavelength management control unit during the wavelength change process, and after the wavelength change process, the optical switch control unit controls the optical switch. When an optical signal having a changed wavelength is input from the subscriber device, the optical switch is controlled so that the input optical signal is output to the transmission line according to the communication destination.
The optical communication device according to any one of claims 1 to 6.
A monitoring unit for monitoring an optical signal transmitted through the transmission line is further provided.
The wavelength management control unit performs the wavelength change processing on the subscriber device based on the information generated by the monitoring in the monitoring unit.
The optical communication device according to claim 8.
The wavelength management control unit performs the wavelength change processing in response to a wavelength change request from the subscriber device.
The optical communication device according to claim 8 or 9.
The optical switch is connected to one or more combiners and one or more demultiplexers.
The combiner combines the optical signals of different wavelengths output from the plurality of second ports and outputs the optical signals to the multiplex communication transmission line.
The demultiplexing device demultiplexes an optical signal received via the multiplex communication transmission line according to a wavelength, and inputs the demultiplexed optical signal to each of the plurality of the second ports.
The optical communication device according to any one of claims 4 to 6.
A monitoring unit that monitors an optical signal transmitted through the multiplex communication transmission line is further provided.
The optical communication device according to claim 11.
The wavelength management control unit performs a wavelength change process for instructing the subscriber device to change the wavelength.
The optical switch control unit controls the optical switch so that an optical signal is transmitted and received between the subscriber device and the wavelength management control unit during the wavelength change process, and after the wavelength change process, the optical switch control unit controls the optical switch. When an optical signal having a changed wavelength is input from the subscriber device, the optical switch is controlled so that the input optical signal is output to the transmission line according to the communication destination.
The optical communication device according to claim 11.
A monitoring unit for monitoring an optical signal transmitted through the multiplex communication transmission line is further provided.
The wavelength management control unit performs the wavelength change processing on the subscriber device based on the information generated by the monitoring in the monitoring unit.
The optical communication device according to claim 13.
The wavelength management control unit performs the wavelength change processing in response to a wavelength change request from the subscriber device.
The optical communication device according to claim 13 or 14.
An optical communication system including a plurality of subscriber devices and the optical communication device according to any one of claims 1 to 15.
The subscriber device
An optical transmitter that transmits an optical signal of the wavelength assigned by the optical communication device, and
It includes one or both of an optical receiving unit that receives an optical signal having a wavelength assigned by the optical communication device.
Optical communication system.
A transfer step in which an optical switch connected to a plurality of transmission lines outputs an optical signal input from one of the transmission lines to the other transmission line.
The wavelength management control unit dynamically assigns the wavelength according to the communication destination to the subscriber device, and the allocation step.
In the transfer step, the optical switch control unit uses the optical signal input from the transmission line as a communication destination specified by a combination of the subscriber device that transmitted the input optical signal and the wavelength of the input optical signal. An optical switch control step that controls the optical switch so as to output to the transmission line according to
Optical communication method having.