WO2022091387A1

WO2022091387A1 - Optical communication device, optical communication system, and optical communication method

Info

Publication number: WO2022091387A1
Application number: PCT/JP2020/040982
Authority: WO
Inventors: 學吉野
Original assignee: 日本電信電話株式会社
Priority date: 2020-10-30
Filing date: 2020-10-30
Publication date: 2022-05-05

Abstract

This optical communication device comprises: an optical switch that is connected to a plurality of transmission paths and outputs, to another transmission path, an optical signal input from any one of the transmission paths; a coupling brancher that branches and outputs the input optical signal to a plurality of ports of the optical switch or multiplexes and outputs the optical signal; and a switch control unit that controls the optical switch so that at least the optical signal output from the coupling brancher to the plurality of ports is output to the plurality of other ports to which the transmission path is connected according to a transfer destination on a route to a communication destination or the optical signal input from the plurality of ports to the coupling brancher is input from the plurality of other ports to which the transmission path is connected according to a route from a device that is the communication destination.

Description

Optical communication equipment, 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.

Networks that provide high-speed Internet using FTTH (Fiber To The Home) and mobile services are inefficient in terms of operation because the networks are constructed independently for each service. Therefore, an optical access system 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 optical access system capable of accommodating multi-services, PON (Passive Optical Network) and WDM (Wavelength Division Multiplexing) -PON using multiple wavelengths are ITU-T (International Telecommunication). It is standardized by the Union Telecommunication Standardization Sector (see, for example, Non-Patent Document 2).

On the other hand, the existing optical access system is equipped with a device on the subscriber side and a terminal device on the station building side, and communication between them is connected to a higher network such as a core network via the terminal device. The device on the subscriber side is, for example, an ONU (Optical Network Unit). 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 optical access that connects to the core network by packet switching, user information and destination information are added or deleted, routing processing, etc. are performed on the signal, and when user information and destination information are added or deleted. May convert an optical signal into an electrical signal once. In that case, some delay occurs in communication. Further, when the amount of data is large, a signal may be stored in the buffer and priority control may be performed. This further increases the delay. The higher the delay, the greater the quality of the optical service. 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 delays that occur. 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.

By the way, when routing using an optical switch, the optical signal path according to the transfer destination on the path to the communication destination of the subscriber side device is set, and further, the transmitter / receiver setting (wavelength) of the subscriber side device is set. Etc.) need to be done. When applying multicast or broadcast or return communication routing using an optical switch to optical access, it is desired to reduce the number of ports used for routing in order to connect many devices.

In view of the above circumstances, an object of the present invention is to provide a technique capable of relaying an optical signal to a destination while reducing the number of ports used.

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 another transmission line, and a plurality of the input optical signals of the optical switch. A branching device that branches and outputs or multiplexes the output to the ports of the above, and a transmission path that corresponds to the transfer destination on the path to the communication destination at least the optical signal output from the branching device to the plurality of ports. An optical signal that is output to a plurality of other ports to which the is connected or is input to the junction / branching device from the plurality of ports is connected to another transmission line according to a path from a device that is a communication source. It is an optical communication device including an optical switch control unit that controls the optical switch so as to input from a plurality of ports.

One aspect of the present invention is a cascade connection between a first optical switch that is connected to a plurality of transmission lines and outputs an optical signal input from one of the transmission lines to another transmission line, and the first optical switch. The optical signal output from the second optical switch and some ports of the first optical switch is branched into a plurality of ports of the second optical switch and output, or the second optical The optical signal output from the plurality of ports of the switch is multiplexed and output to the first optical switch, and the optical signal transmitted from the subscriber device is transferred on the path to the communication destination. It is an optical communication device including an optical switch control unit that controls the first optical switch and the second optical switch so as to output to a transmission path according to the above.

One aspect of the present invention is a first optical switch that is connected to a plurality of transmission lines and outputs an optical signal input from any of the transmission lines to another transmission line, and a second optical switch of the first optical switch. A second optical switch connected to a port is provided, and the second optical switch inputs an optical signal output from the second port, and the input optical signal is used in the first optical switch. It is an optical communication device that outputs to another second port.

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 another transmission line, and an optical signal transmitted from each of the plurality of subscriber devices. Is input via the optical switch, the input optical signal is converted into an electric signal and multiplexed, and the multiplexed electric signal is modulated and converted into an optical signal having a plurality of wavelengths and input to the optical switch. An electric processing unit that converts the multiplexed or multiplexed electric signal into one or more optical signals having one or more wavelengths and inputs the optical signal to the optical switch, and a plurality of inputs to the optical switch. The optical signal is output to the electric processing unit according to the combination of the plurality of subscriber devices that transmitted the input optical signal and the wavelength of the input optical signal, and is input from the electric processing unit. It is an optical communication device including an optical switch control unit that controls the optical switch so as to output the signal to the transmission path corresponding to the transfer on the path to the communication destination.

One aspect of the present invention includes a plurality of optical switches connected to a plurality of transmission lines and outputting an optical signal input from any of the transmission lines to another transmission line, and a first port of the plurality of optical switches. It comprises another optical switch different from the plurality of optical switches connected to a second port on a side different from the first port, and the other optical switch is the first optical of the plurality of optical switches. It is an optical communication device that connects the second port of the switch and the first port of the second optical switch among the plurality of optical switches.

One aspect of the present invention comprises a plurality of optical switches connected to a plurality of transmission lines and outputting an optical signal input from one of the transmission lines to another transmission line, and ports on the same side of different optical switches. It is an optical communication device that connects the above with a return transmission line.

One aspect of the present invention is a plurality of optical switches connected to a plurality of transmission lines and outputting an optical signal input from any of the transmission lines to another transmission line, and a second port of the plurality of optical switches. With another optical switch, a part of which is connected to the first port, another part of the second port of the plurality of optical switches is connected to the second port, and the second ports of the plurality of optical switches are connected to each other. It is an optical communication device provided with.

One aspect of the present invention is an optical communication system having a plurality of subscriber devices and the above-mentioned optical communication device.

In one aspect of the present invention, an optical switch is connected to a plurality of transmission lines, an optical signal input from any of the transmission lines is output to another transmission line, and a junction branching device outputs the input optical signal. , The optical switch is branched to a plurality of ports of the optical switch and output or multiplexed and output, and the optical switch control unit at least outputs an optical signal output from the combiner to the plurality of ports on a path to a communication destination. An optical signal that is output to a plurality of connected ports or input to the junction branch from the plurality of ports is transmitted according to the path from the device that is the communication source. It is an optical communication method that controls the optical switch so that it inputs from a plurality of other ports to which a channel is connected.

According to the present invention, it is possible to relay an optical signal to a destination while reducing the number of ports used.

It is a figure which shows the basic configuration example of the optical communication system by embodiment. It is a figure which shows the example of the optical SW by a basic configuration. It is a figure which shows the example of the optical SW by a basic configuration. It is a figure which shows the example of the optical SW by a basic configuration. It is a figure which shows the example of the optical SW by a basic configuration. It is a figure which shows the example of the optical SW by a basic configuration. It is a figure which shows the example of the routing before the wavelength change in the optical SW by a basic configuration. It is a figure which shows the example of the routing after the wavelength change in the optical SW by a basic configuration. It is a figure which shows the example of the optical SW by a basic configuration. It is a figure which shows the example of the optical SW by a basic configuration. It is a figure which shows the example of the optical SW by a basic configuration. It is a figure which shows the example of the optical SW by a basic configuration. It is a figure which shows the example of the optical SW by a basic configuration. It is a figure which shows the example of the optical SW by a basic configuration. It is a figure which shows the example of the optical SW by a basic configuration. It is a figure which shows the example of the access topology by the basic configuration. It is a figure which shows the example of the access topology by the basic configuration. It is a figure which shows the example of the access topology by the basic configuration. It is a figure which shows the example of the access topology by the basic configuration. It is a figure which shows the example of the access topology by the basic configuration. It is a figure which shows the example of the access topology by the basic configuration. It is a figure which shows the example of the access topology by the basic configuration. It is a figure which shows the example of the access topology by the basic configuration. It is a figure which shows the example of the access topology by the basic configuration. It is a figure which shows the example of the access topology by the basic configuration. It is a figure which shows the example which the scalability of an optical SW by a basic configuration is required. It is a figure which shows the example which the scalability of an optical SW by a basic configuration is required. It is a figure which shows the example which the scalability of an optical SW by a basic configuration is required. It is a figure which shows the configuration example of the two-core type subscriber apparatus by the basic configuration. It is a figure which shows the configuration example of the two-core type subscriber apparatus by the basic configuration. It is a figure which shows the configuration example of the one-core type subscriber apparatus by the basic configuration. It is a figure which shows the configuration example of the one-core type subscriber apparatus by the basic configuration. It is a figure which shows the configuration example of the monitoring part by the basic configuration. It is a figure which shows the configuration example of the monitoring part by the basic configuration. It is a figure which shows the configuration example of the monitoring part by the basic configuration. It is a figure which shows the configuration example of the monitoring part by the basic configuration. It is a figure which shows the configuration example of the monitoring part by the basic configuration. It is a figure which shows the configuration example of the optical access system by the configuration example. It is a figure which shows the example of the SW connection table by the same configuration example. It is a figure which shows the example of the user wavelength table by the same configuration example. It is a figure which shows the example of the wavelength table between stations by the same configuration example. It is a flowchart which shows the initial setting process of an optical access system by the same configuration example. It is a figure which shows the configuration example of the optical access system by the 1st configuration example. It is a figure which shows the configuration example of the optical access system by the 2nd configuration example. It is a figure which shows the configuration example of the optical access system by the 3rd configuration example. It is a figure which shows the configuration example of the optical access system by the 4th configuration example. It is a figure which shows the configuration example of the optical access system by the 5th configuration example. It is a figure which shows the structural example of the optical access system by the 6th structural example. It is a figure which shows the configuration example of the optical access system by the 7th configuration example. It is a figure which shows the structural example of the optical access system by 8th structural example. It is a figure which shows the configuration example of the optical access system by the 9th configuration example. It is a figure which shows the configuration example of the optical access system by the tenth configuration example. It is a figure which shows the configuration example of the optical access system by the eleventh configuration example. It is a figure which shows the configuration example of the optical access system by the twelfth configuration example. It is a figure which shows the configuration example of the optical access system by the thirteenth configuration example. It is a figure which shows the configuration example of the optical access system by the 14th configuration example. It is a figure which shows the configuration example of the optical access system by the fifteenth configuration example. It is a figure which shows the structural example of the optical access system by the 16th structural example. It is a figure which shows the configuration example of the optical access system by the 16th configuration example when the electric processing unit performs signal multiplexing. It is a figure which shows the configuration example of the optical access system by the 17th configuration example. It is a figure which shows the structural example of the optical GW in the optical access system of 1st Embodiment. It is a figure which shows the structural example of the optical GW in the optical access system of 2nd Embodiment. It is a figure which shows the structural example of the optical GW in the optical access system of 3rd Embodiment. It is a figure which shows the structural example of the optical GW in the optical access system of 4th Embodiment. It is a figure which shows the structural example of the optical GW in the optical access system of 5th Embodiment. It is a figure which shows the other aspect of the scalability of an optical SW. It is a figure which shows the other aspect of the monitoring part. It is a figure which shows the other aspect of the monitoring part. It is a figure which shows the other aspect of the monitoring part. It is a figure which shows the modification of the optical access system.

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 following description, first, the basic configuration of the present invention will be described, and then specific embodiments will be described.

(Basic configuration)
First, the basic configuration of the present invention will be described with reference to FIGS. 1 to 41.
FIG. 1 is a diagram showing a basic configuration example of the optical communication system 1 of the present embodiment. The optical communication system 1 has one or a plurality of optical SWs (switches) 10. Although 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.
When the optical SW10 is controlled by an optical signal, the optical SW10 includes at least an optical receiver that receives the optical signal, but the description thereof will be omitted in the following description.

The optical SW10 communicates with another optical SW10 via the optical communication network 30. For the optical communication network 30, for example, a WDM 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. The subscriber device 40 has an optical transceiver 41. The optical transceiver 41 is an example of the configuration of an optical transmitter unit and an optical receiver unit in a 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 (which may include an operation system (OpS) or the like, or the OpS may include a control unit 20; the same shall apply hereinafter) is connected to any port of the optical SW10, for example, port 2. May be good. The control unit 20 may be installed in a building different from the optical SW10 and may be connected to the optical SW10 and the optical SW control unit (not shown in FIG. 1) via a network. The control unit 20 may be connected to a port of the optical SW10 that is not connected to the subscriber device 40, another optical SW10, a higher-level network, another transmission line to the ground, or the like. The control unit 20 may be installed for each optical SW10 or for each plurality of optical SW10s.

When the control unit 20 controls the optical SW 10 with an optical signal, the control unit 20 has one or a plurality of optical transceivers 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. When there are a plurality of optical transceivers 21, the ports that can be connected are different for each port of the optical SW10, the ports that control the subscriber device 40 and the optical SW10 are different, or the control target is the plurality of optical SW10s or the plurality of optical SW10s. It is suitable for at least one of the subscriber devices 40 to be connected to, and when the connectable ports are different from each other. If there are a plurality of optical SW10s, they may be connected by a transmission line, and if the ports are different, they may be connected by a return connection using a return transmission line or the like described later, so that a single optical transmitter / receiver may be used. When the control unit is equipped with a transmitter and the subscriber device is equipped with a receiver, the transmitting side of the control unit 20 is provided on the receiving side of the subscriber device 40, the control unit 20 is provided with a receiver, and the subscriber device 40 is provided with a transmitter. At this time, the receiving side of the control unit 20 is connected to the transmitting side of the subscriber device 40.

When only the optical transmitter / receiver or the modulation unit of the monitoring unit described later is used, the optical transmitter / receiver may not be provided. When the control unit 20 controls the subscriber device 40 with an optical signal, and when the control unit 20 performs wavelength allocation processing to the subscriber device 40 by an optical signal via the optical SW 10, the subscriber device 40 and the control unit 20 The optical SW10 is controlled so as to transmit and receive an optical signal between the subscribers, and after the wavelength allocation process, the optical signal input from the transmission path is input to the subscriber, the subscriber device 40, the port of the optical SW10, the wavelength of the optical signal, and the subscriber device 40. The optical SW10 is controlled so as to output to a port corresponding to the transfer destination specified by the combination of the light and the wavelength of the optical signal, the combination of the port and the wavelength of the optical signal, and the like.
When wavelength allocation processing is performed via the monitoring unit in the previous stage of the optical SW10, optical signals are transmitted and received between the monitoring unit and the subscriber device 40, and after the allocation processing, they are output to the port corresponding to the specified transfer destination. The optical SW10 is controlled so as to do so.
When wavelength allocation processing or the like is performed via the monitoring unit in the subsequent stage of the optical SW10, the optical SW10 is controlled so that the optical signal is output to the port corresponding to the specified transfer destination, and the output from the port is blocked by the blocking unit. In this state, an optical signal is transmitted and received between the monitoring unit and the subscriber device 40, and after the allocation process, the cutoff is released.
When the wavelength allocation process or the like is performed before the connection to the optical SW10, the optical SW10 is controlled so as to output the optical signal to the port corresponding to the specified transfer destination after the wavelength allocation process.
The control unit 20 has or connects to a management database (DB) such as a SW connection table and a wavelength table.

When the control unit 20 connects to the management DB, information on the user and the wavelength used is exchanged with the management DB. The management database stores the wavelength used by each user, destination information, and transfer destination information. The destination or transfer destination is, for example, in the case of ground A or the like, the ground A or ground B, in the case of the subscriber device 40, the identifier of the subscriber device 40, or the identifier of the transmission line or the port to which the device is connected. , It is represented by the identifier of the device, component or function that goes through on the way, or the identifier of the port to which they are connected. The management DB manages the information of the user connected to the optical access system.

The SW connection table shows the connection destination of each port of the optical SW10. That is, the port to which the optical signal is input / output can be used as information for identifying the subscriber device, control unit, monitoring unit, ground, etc. of the source or destination of the optical signal.
The wavelength table is data indicating the wavelength assigned to each subscriber device 40 or the like. The wavelength table may be divided into a user wavelength table and an inter-station wavelength table.

The user wavelength table shows, for example, a wavelength used for transmission by a user, a wavelength used for reception, a usable wavelength not used for transmission / reception, and a wavelength that cannot be used due to a failure.
The inter-station wavelength table can be, for example, a wavelength used by one ground for communication with each other ground, a usable wavelength not used for communication with each other ground, and a wavelength table with each other ground. Indicates a wavelength that cannot be used due to a communication failure.
In order to assign a wavelength corresponding to the transfer destination on the route to the communication destination to the subscriber device 40, first, the optical transmitter / receiver of the subscriber device 40 or the like and the optical transmitter / receiver of the control unit 20 communicate with each other. The control unit 20 refers to the wavelength table and selects the wavelength to be assigned to the subscriber device 40 or the like according to the transfer destination on the route to the communication destination.

For example, the wavelength control unit of the control unit 20 allocates the wavelength used by the user with reference to the information indicating the wavelength used by the user or the service. By sharing each connection information, the wavelength control unit manages and controls information on which user is connected to which port of the optical SW10 and which wavelength is used.
When selecting a wavelength, if the wavelength is multiplexed in the section constituting the path in the middle and it is identified by the wavelength, an empty wavelength is a usable wavelength in the section constituting the path, and the available wavelength is used. select.

On the contrary, it is not necessary to consider the empty wavelength of the section that is not wavelength-multiplexed in the section constituting the route in the middle, and it is not identified or branched only by the wavelength (for example, time division multiplexing, code division multiplexing, mode division multiplexing, core division). In the case of multiplex, core wire multiplexing, spatial division multiplexing, frequency division multiplexing, polarization division multiplexing or a combination thereof, or a combination of them and wavelength division multiplexing, etc.), identification in that section, and vacancy in that section if branching is possible. Wavelengths other than the above are also usable wavelengths and may be selected. When wavelength conversion is performed in the middle of the path, wavelength division multiplexing is not performed in the empty wavelength of the section constituting the path up to wavelength conversion or in the section constituting the path in the middle of wavelength conversion, or identification is performed only by wavelength. If it is not branched, it is not necessary to select an empty wavelength.

As described above, since the wavelength to be selected does not depend only on the usage status of the wavelength in the section constituting the route in the middle, the wavelength table shows not only the free wavelength but also the usable wavelength in consideration of the combination with other multiplexes. Is desirable. Further, since the usable wavelength depends on the usage status and the multiplex status of the section constituting the route in the middle, the control unit identifies the usable wavelength AND (or other elements other than the wavelength) for each section constituting the path. , OR of wavelengths that cannot be separated) is the wavelength that can be used.

When the destination port of the optical SW10 is set by the wavelength of the subscriber device 40 to be transmitted, the ports constituting the optical SW10 are divided into two groups, for example, port 1 and port 2, and the groups are connected and not connected within the group. The wavelengths that can be used may be different between the direction from port 1 which is one group to port 2 which is the other group and the direction from port 2 which is the other group to port 1 which is one group.

The wavelength allocation process is closed when all the sections constituting the route are controlled or managed by the same control unit, but when multiple control units or external devices control or manage, they operate in cooperation. Or, it may be controlled by receiving the authority to use the wavelength table itself, which shows the wavelengths that can be used, or its value.
The control unit 20 sets the wavelength selected for the subscriber device 40 by the control signal. After that, the control unit 20 sets the optical SW 10 so as to output the optical signal transmitted from the subscriber device 40 according to the destination or the transfer destination.

When the subscriber devices 40 face each other via the optical SW10, the subscriber devices 40 facing each other are connected by this. When the subscriber devices 40 pass through the devices, parts, or functional units in the middle of the connecting route, the connection is made after passing through them. The optical SW 10 may be connected to the subscriber device 40, a device, a component, a functional unit, or an opposite subscriber device 40 via the subscriber device 40 as it is, or may be connected at the same wavelength after performing photoelectric conversion or other processing, or may remain as light. Alternatively, after performing photoelectric conversion or other processing, they may be connected at different wavelengths by at least a part of the paths. For example, when both the subscriber device and the device, component, or function that passes through the route are connected to the same optical SW, the routing is routed from the subscriber device to the next device, component, or function. From the device / part / function to be routed to the device / part / function to be routed next, to the device / part / function to be routed last, to the subscriber device to be opposed. The routing from the subscriber device that is the communication source to the opposite subscriber device that is the communication partner is a setting when the device, parts, or functions to be routed are not routed. At the time of routing, in addition to the source or the destination including the route, the identification of multiple conveniences such as wavelength may be added to the parameter. This is because multiple optical signals with different wavelengths and optical frequencies are aggregated and transmitted within the same station or at different ground optical switches, or multiple optical signals with different wavelengths and optical frequencies are transmitted by different devices and components. It is suitable for demultiplexing and distributing to functions and subscriber devices.

The control unit 20 allocates a wavelength used for communication by the subscriber device 40, for example, by using an AMCC function that uses a control signal that is slower than the main signal that is an optical signal between the subscriber devices 40 and can be superimposed on the main signal. .. Hereinafter, communication between the subscriber device 40 and the control unit 20 will be illustrated by the AMCC function, but the present invention is not limited thereto. In particular, when initial setting or setting change of wavelength or the like is performed in a state where the main signal does not conduct with the opposite device, the control signal may be exchanged as the main signal without using AMCC or the like different from the main signal. .. Any modulation method may be used as long as it can be realized by the functions of the subscriber device 40 and the control unit 20.

For example, in order to allocate a wavelength according to the transfer destination on the route to the communication 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. I do. The control unit 20 refers to the wavelength table and selects the wavelength to be assigned to the subscriber device 40 according to the transfer destination on the route to the communication destination. As an example, the control unit 20 selects a wavelength from free wavelengths that are not used in other paths in a link that multiplexes wavelengths on the path. The control unit 20 may assign individual wavelengths to the subscriber devices 40. The control unit 20 sets the selected wavelength in the subscriber device 40 by the control signal using the AMCC. After that, the control unit 20 switches the optical SW 10 so as to output the optical signal transmitted from the subscriber device 40 to the transmission path corresponding to the transfer destination on the path to the communication destination.

The control unit 20 may control the optical switch so as to perform routing according to the destination information. As the destination information, a set such as a subscriber device, a wavelength, an input port, an output port, a subscriber device or an input port, or a pair of an output port and a wavelength may be used.
In the following embodiment, the case where the subscriber device and the wavelength set are mainly used as the destination information will be described.
As a result, the subscriber devices 40 facing each other are connected.

The control unit 20 may perform a wavelength change process instructing the subscriber device 40 to which the wavelength is assigned to change the wavelength. For example, the target subscriber device 40 is specified based on the monitoring information output from the monitoring unit described later, and the wavelength change processing is performed on the specified subscriber device 40.
The instruction from the control unit 20 to the subscriber device 40 may be given by the route at the time of initial setting, or may be given from the monitoring unit or the like.
The control unit 20 controls the optical SW 10 or the blocking unit, if any, so as not to transmit the optical signal of the target subscriber device 40 during the wavelength change. When the control unit 20 directly controls the subscriber device 40 with an optical signal, the optical SW 10 is controlled so that the optical signal is transmitted and received between the subscriber device 40 and the wavelength control unit.

For example, if there is no other influence on the output side before the wavelength change, the output port is switched after the wavelength change, and if there is no other influence on the output side after the wavelength change, the output port is switched before the wavelength change. The transmission may be stopped by a device other than the optical SW10.
For example, the transmission line with the subscriber device 40 or the subscriber device 40 is removed from the optical SW10, and the connection is reconnected after the setting. Alternatively, a transmission line, an optical SW10, a turnout or a demultiplexer, or a connection point thereof is provided with a cutoff portion, and the cutoff portion is cut off before the wavelength is changed, and the output port is switched before or switched as necessary. After that, set it to cancel the blocking.

For example, the optical SW control unit controls the optical SW 10 so that after the wavelength change processing, the subscriber device 40 outputs the optical signal of the changed wavelength from the port 2 according to the communication destination or the transfer destination.
At the time of wavelength switching, if the wavelength switching affects other, for example, another subscriber device 40, the optical output in that direction is cut off. Specifically, the transmission of the optical signal itself is stopped, the connection to the optical SW10 is disconnected, the connection from the input side to the output side of the optical SW10 is released, and the optical signal is cut off by a blocking unit included in, for example, a monitoring unit or the like. ..

In the wavelength allocation process, the optical SW control unit controls the path in the optical SW 10 so that the optical SW 10 does not transmit the optical signal of the subscriber device 40 subject to wavelength allocation. That is, the optical SW control unit does not output the optical signal transmitted from the subscriber device 40 to a port (other port) other than the port connected to the monitoring unit of the subscriber device 40 to be wavelength-assigned. In addition, the path in the optical SW10 is controlled.

If there is no particular effect even if the output destination of the optical SW10 is switched before the wavelength is set (before the wavelength is assigned), the optical SW control unit may switch the output destination of the optical SW10 before changing the wavelength. During the wavelength allocation process, a functional unit other than the optical SW 10 may stop the transmission of the optical signal transmitted from the subscriber device 40.

When the wavelength is switched and the optical SW10 is switched, and the wavelength is switched while connected to the route before or after the switching, there is no influence.
The wavelength allocation process (wavelength setting) and the route setting process are executed in this order. The optical SW control unit switches the output destination (path) of the optical SW 10 after changing the wavelength so that there is no particular effect even if the output destination of the optical SW 10 is switched.
For example, when the first port and the first wavelength "λ1" are used before the switching and the second port and the second wavelength "λ2" are used after the switching, the following may be used.

(1) When there is no subscriber device 40 using the first port and the second wavelength "λ2":
There is no effect even if the first wavelength is switched from the first wavelength "λ1" to the second wavelength "λ2" at the first port. In this case, it is possible to switch the wavelength before switching the port.
(2) When there is a subscriber device 40 using the first port and the second wavelength "λ2":
Switching from the first wavelength "λ1" to the second wavelength "λ2" at the first port has an effect. In this case, it is impossible to switch the wavelength before switching the port.
(3) When there is no subscriber device 40 using the second port and the first wavelength "λ1":
There is no effect even if the first wavelength "λ1" is switched to the second wavelength "λ2" at the second port. In this case, it is possible to switch the wavelength before switching the port.
(4) When there is a subscriber device 40 using the second port and the first wavelength "λ1":
Switching from the first wavelength "λ1" to the second wavelength "λ2" at the second port has an effect. In this case, it is impossible to switch the wavelength before switching the port.

In the above "(1)" and "(3) or (4)", it is possible to switch the wavelength before switching the port.
In the above "(1) or (2)" and "(3)", it is possible to switch the wavelength before switching the port.
In the above "(2)" and "(4)", it is impossible to switch the wavelength before switching the port, and it is necessary to stop or cut off the optical signal.

In the wavelength allocation process, the wavelength control unit executes the wavelength allocation process for the subscriber device 40 to be wavelength-allocated via the monitoring unit. The wavelength control unit executes, for example, a new wavelength allocation process having the same wavelength as or different from the wavelength used when the abnormality is detected for the subscriber device 40 to be wavelength-allocated.

In the route setting process, the optical switch control unit connects the subscriber device 40 to be wavelength-assigned to a port (other port) other than the port connected to the monitoring unit of the subscriber device 40 to be wavelength-assigned. As described above, the path in the optical SW10 is controlled. For example, the optical switch control unit sets the optical SW10 so as to output the optical signal input from the transmission path of the subscriber device 40 to be wavelength-assigned to the port (other port) specified according to the transfer destination. Control. Here, the transfer destination is the subscriber, the subscriber device 40, the port of the optical SW10, the wavelength of the optical signal, the combination of the subscriber device 40 and the wavelength of the optical signal, the combination of the wavelength of the port 1 optical signal, and the like. Specified according to.

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 15.

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 includes ports 11-1-1 to 11-1-P (P is an integer of 1 or more) and ports 11-2-1 to 11-2-Q (Q is an integer of 1 or more, P and Q). At least one of them has 2 or more). When any one of ports 11-1-1 to 11-1-P is not specified, or collectively, it is described as port 11-1, and any one 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 the 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. 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 40a-1, 40a-2, 40a-, which are subscriber devices 40 to the ground A, via transmission lines 50-1, respectively. 3, ... is connected. One of the ports 11-2 (port 11-2-1 in the figure) is connected to the wavelength control unit 25 described later. Some ports 11-2-i, 11-2- (i + 1), 11-2- (i + 2), ... Are 40b-1 which is a subscriber device 40 to ground B via a transmission line 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), ... 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. Here, as a configuration via another optical communication device such as an optical SW or an optical communication network 30 between the subscriber device 40 of the ground A and the subscriber device 40 of the ground B and the subscriber device 40 of the ground C. May be good.

The optical SW10a is connected to the control unit 20. The control unit 20 includes a wavelength control unit 25 and an optical SW control unit 26. The wavelength control unit 25 receives a wavelength allocation request from the subscriber device 40 by an optical signal, allocates a wavelength according to the transfer destination on the route to the communication destination to the subscriber device 40 that has transmitted the request, and assigns the wavelength. A wavelength allocation process for notifying the subscriber device 40 of the wavelength by an optical signal is performed. For example, the wavelength control unit 25 may dynamically assign the wavelength according to the transfer destination on the route to the communication destination to the subscriber device 40 that has transmitted the request. For the optical signal transmitted and received between the wavelength control unit 25 and the subscriber device 40, it is desirable to use a control signal superimposition method that does not depend on the communication protocol of the optical signal (main signal) between the subscriber devices 40. .. For example, a protocol-free AMCC is used as an optical signal transmitted / received between the wavelength control unit 25 and the subscriber device 40. The main signal may be transmitted / received and set without using the control signal superimposed by AMCC or the like.

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 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 transfer destination on the path to.

Each transmission line 50-2 is provided with a monitoring unit 60. In the figure, only one monitoring unit 60 is shown. The monitoring unit 60 has a power splitter 61. The power splitter 61 branches an optical signal transmitted through the transmission line 50-2. The monitoring unit 60 monitors the optical signal branched by the power splitter 61. The monitoring unit 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. For example, when a change request from the subscriber device 40 using a control signal or an abnormality in the communication status between the subscriber devices 40 is detected by monitoring an optical signal, it is communicated that an abnormality in the communication status has occurred. The monitoring information set with the information for identifying the subscriber device 40 in which the abnormal situation has occurred is output. Abnormalities in communication status include, for example, wavelength deviation, increase or decrease in output, communication abnormality (error), and the like. As the output destination of the monitoring information, for example, the control unit 20 may be mentioned. When an abnormality is detected, the control unit 20 controls, for example, the optical SW10 or the monitoring unit or the blocking unit so as not to transmit the optical signal of the target subscriber device 40. Further, when the control unit 20 directly controls the subscriber device 40 with an optical signal, the optical SW 10 is controlled so that the subscriber device 40 is reconnected to the control unit 20. Then, the control unit 20 performs allocation processing of a new wavelength that is the same as or different from the wavelength at the time of detection of the abnormality, as in the case of newly connecting the subscriber device 40. As a result, the optical SW 10 connects the optical signal of the wavelength before or after the change from the subscriber device 40 to the port before the change by the subscriber device 40. In addition, if it does not recover from the abnormal state even if the predetermined processing such as restarting or reassignment is performed a predetermined number of times due to a failure or Logue ONU, etc., or if it is registered in the blacklist or the same operation is performed in the past, subscription Depending on the identification number and behavior of the device, the connection in the optical SW may be opened, the connection may be cut off by the blocking unit, or the setting, connection, or transfer may be stopped. During communication with another subscriber device 40, the power splitter 61 may branch the control signal transmitted by the subscriber device 40, or superimpose and output the control signal on the subscriber device 40 or the like. can.

When the subscriber device 40 is connected to the transmission line 50-2, the control unit 20 may be connected to the port 11-1. Alternatively, when the subscriber device 40 is connected to the transmission line 50-2, the subscriber device 40 connected to the transmission line 50-2 may be connected to the control unit 20 via the folded transmission line 73. good. The return transmission line 73 is an optical fiber, an optical switch, or an optical branching device that inputs an optical signal output from port 11-1-p1 to another port 11-1-p2 (p1 and p2 are integers of 1 or more and P or less). And optical demultiplexer. In this case, the optical signal transmitted from the

subscriber device

40b or 40c is input to the optical SW10a via the transmission line 50-2. The optical SW10a outputs the optical signal input from the transmission line 50-2 to the port 11-1-p1, and inputs the optical signal transmitted through the return transmission line 73 from the port 11-1-p2. The optical SW10a outputs an optical signal input from the port 11-1-p2 to the control unit 20 from the port 11-2-1. As a result, the

subscriber device

40b or 40c is connected to the control unit 20.

The wavelength 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 or the like. Here, the wavelength change process is shown as an example in which the subscriber device 40 communicates with the control unit by using the monitoring information as an opportunity. For example, the wavelength control unit 25 identifies the subscriber device 40 to be wavelength-changed based on the monitoring information output from the monitoring unit 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 control unit 25 during the wavelength change processing. After the wavelength change processing, the optical SW control unit 26 outputs an optical signal transmitted from the subscriber device 40 at the changed wavelength to the transmission line 50-2 according to the transfer destination on the path to the communication destination. The light SW10a is controlled. For example, the optical SW control unit 26 uses the optical signal of the changed wavelength from the subscriber device 40 after the wavelength change process, which is the communication destination used by the combination of the source subscriber device 40 and the wavelength before the change. The optical SW10a is controlled so as to output to the transmission path 50-2 according to the transfer destination on the path to. Alternatively, the optical SW10a may be controlled so that the optical signal of the changed wavelength is output to the transmission line 50-2 different from that before the wavelength change. In this case, the subscriber device 40 of the transfer destination on the route to the communication destination is different before and after the wavelength change processing. The wavelength 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.

The monitoring information used in the wavelength change processing includes, for example, a change request from the subscriber device 40 using a control signal, an abnormality in the communication status such as a wavelength shift, an increase or decrease in output, and a communication abnormality (error). , Designation and setting of the wavelength to be used, modulation method, protocol, etc., deviation from the allowable range, use of unassigned wavelength, etc., and abnormality detection such as signal disconnection may be performed, other than monitoring signals. It may be an opportunity, for example, a request to change the transmission destination via a signal that passes through the main signal or does not pass through the optical SW, and abnormal detection, stoppage, or change from devices inside or outside the network such as the transmission path or the management system. It may be a request of. If the wavelength or the like is not changed within the specified, set, or permissible range when anomaly detection, stop, or change is requested, the subscriber device 40 is instructed to restart, etc., and the signal is transmitted while the signal is connected to the control unit. The state where the signal is not output to the road or the signal may be blocked by a shutter or the like. The communication between the control unit 20 and the subscriber device 40 may be performed by the AMCC or by the main signal. When the subscriber device 40 does not support AMCC, it is preferable to use the main signal. If the wavelength before switching does not adversely affect the device facing the device before switching, the monitoring unit or the like sets the route with the subscriber device 40 facing the control unit 20 without switching the connection. If the wavelength or the like after switching does not adversely affect the device facing the device after switching, the monitoring unit or the like may switch the route with the subscriber device 40 facing the device without switching the connection with the control unit 20. It may be set.

FIG. 3 is a diagram showing a configuration example of an optical SW10b having a folding circuit for folding communication. 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. In FIG. 3, the description of the control unit 20 is omitted. If it is not particularly necessary in the following description, the description of the control unit 20 will be omitted in the drawings. The optical SW10b is connected to the folded transmission line 51. The folded transmission line 51 is an optical fiber, an optical switch, an optical branching device, or an optical duplexer that inputs an optical signal output from port 11-2 to another port 11-2. As a result, the optical SW10b enables return communication.

When the port of the optical signal output destination is set by the combination of the subscriber device 40 of the transmission source and the wavelength, the direction of the port 11-2 to which the return transmission line 51 is connected from the port 11-1 and the return transmission. The destination may be different depending on the direction from port 11-2 to port 11-1 to which the road 51 is connected.

FIG. 4 is a diagram showing a configuration example of an optical SW10c that performs uplink multicast using a one-to-one return transmission line and a one-to-other return transmission line that face each other. 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 SW10c has a distribution unit 58 that distributes the optical signal output by the port 11-2 to a plurality of components and inputs the distributed optical signals to different ports 11-1. In FIG. 4, the optical SW10c inputs the optical signal output from the port 11-2 to another port 11-2 via the folded 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 optical signal in the downlink direction is routed in the reverse direction to the uplink direction.

The optical SW10c may input optical signals having a plurality of wavelengths from the port 11-1. In this case, the optical SW10c distributes the optical signals of a plurality of wavelengths input from the port 11-1 by the distribution unit 58, and distributes the distributed optical signals to each subscriber device 40 or other ground connected to the port 11-2. Output to the transmission line connected to. The subscriber device 40 connected to the port 11-2 selects and receives an optical signal having a predetermined wavelength from the optical signals having a plurality of wavelengths. The transmission line connected to the other ground may transmit an optical signal having a plurality of wavelengths as it is, or may transmit an optical signal having a wavelength selected by the WDM device shown in FIG. 6 described later.

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. The optical SW10d has a distribution unit 59 that distributes the optical signal output by the port 11-1 to a plurality of components and inputs the distributed optical signals to different ports 11-2. In FIG. 5, the optical SW10d inputs the optical signal output from the port 11-1 to the other port 11-1 via the folded 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.

Note that optical signals having a plurality of wavelengths may be input to the optical SW10d from the port 11-2. In this case, in the optical SW10d, the optical signals of a plurality of wavelengths input from the port 11-2 are distributed by the distribution unit 59, and the distributed optical signal is output to each subscriber device 40 connected to the port 11-1. Will be done. Each subscriber device 40 connected to the port 11-1 selects and receives an optical signal having a predetermined wavelength from the received optical signals having a plurality of wavelengths.

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. 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. As described above, the WDM device 80 has the function of the combiner and the function of the demultiplexer. The function of the combiner is to combine optical signals of different wavelengths output from the plurality of ports 11-2 of the optical SW10e and output them to the multiplex communication transmission line 90. As a function of the demultiplexing device, an optical signal received via the multiplex communication transmission line 90 is demultiplexed by wavelength, and each demultiplexed optical signal is input to a plurality of ports 11-2 having different optical SW10e. The optical SW10e that performs WDM transmission may connect the folded 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 unit 65. The monitoring unit 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 unit 65 monitors the optical signal demultiplexed by the WDM device 67 and the WDM device 68. The monitoring unit 65 generates monitoring information based on the monitoring result and outputs the generated monitoring information.

The monitoring unit 65 may be provided with a power splitter 69 in each transmission line between the port 11-2 and the WDM device 80. The power splitter 69 branches an optical signal transmitted through a transmission line between the port 11-2 and the WDM device 80, and outputs the branched optical signal to the control unit 20.

The wavelength 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 control unit 25 identifies the subscriber device 40 to be wavelength-changed based on the monitoring information output from the monitoring unit 65, and performs wavelength change processing on the specified subscriber device 40. The optical SW control unit 26 controls, for example, reconnects the optical SW10e via, for example, a monitoring unit so that an optical signal is transmitted and received between the subscriber device 40 and the wavelength control unit 25 during the wavelength change processing. .. When the optical SW control unit 26 inputs an optical signal having the changed wavelength from the subscriber device 40 after the wavelength change processing, the optical SW control unit 26 transfers the input optical signal to the port 11 according to the transfer destination on the path to the communication destination. The optical SW10e is controlled so as to output from -2. The wavelength 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 is the subscriber device 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 SW 10e has a port 11 different from the optical signal having the wavelength λ ₁ input from the subscriber device 40a-1 and the optical signal having the wavelength λ ₂ input from the subscriber device 40a-2. -The output is output from -2 to the WDM device 80b. The subscriber device 40a-2 transmits a wavelength change request to the wavelength control unit 25 by a control signal during or after communication. Upon receiving the wavelength change request from the subscriber device 40a-2, the wavelength control unit 25 performs a wavelength change process instructing the subscriber device 40a-2 to change to the wavelength λ ₁₀ . The optical SW control unit 26, the monitoring unit, or the blocking unit prevents the optical signal of wavelength λ ₁₀ received from the subscriber device 40a-2 from being output until the wavelength change is completed, and the optical SW control unit 26 controls the optical SW control unit 26. After the switching is completed, the optical SW10e is controlled so as to output from the port 11-2 corresponding to the wavelength λ ₁₀ to the WDM device 80b. The wavelength control unit 25 may further change the wavelength used for reception by the subscriber device 40a-2.

After the wavelength change processing, the optical SW control unit 26 sets the optical SW10e so as to output the optical signal transmitted from the source subscriber device 40 using the changed wavelength to the WDM device 80 different from that before the wavelength change. You may control it. 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 control unit 25 by a control signal during or after communication. When the wavelength control unit 25 receives the wavelength change request from the subscriber device 40a-2, the wavelength 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. I do. The optical SW control unit 26 or the monitoring unit or the blocking unit does not output the optical signal of wavelength λ ₁₀ input from the subscriber device 40a-2 until the wavelength change is completed, if necessary, and after the switching is completed, the optical SW control unit The unit 26 controls the optical SW10e so that the optical signal of the wavelength λ ₁₁ received from the subscriber device 40a-2 is output from the port 11-2 corresponding to the wavelength λ ₁₁ to the WDM device 80c. The wavelength control unit 25 may further change the wavelength used for reception by the subscriber device 40a-2.

If the subscriber device 40a-2 does not change the wavelength used for reception, the wavelength control unit 25 may operate as follows. If the wavelength is not used as at least a part of the destination information, the following may not be used.
(1) The wavelength control unit 25 releases the transmission wavelength used by the subscriber device 40 of the ground B, which is the communication destination before the wavelength switching. By releasing the transmission wavelength, the route from the subscriber device 40a-2 to the subscriber device 40 to the ground B is reset. After that, the wavelength control unit 25 reassigns the wavelength, which has become an empty wavelength due to the release, for receiving a signal from the subscriber device 40 of the ground C, which is the new communication destination, to the subscriber device 40a-2. This is performed when the wavelength used for each subscriber device 40 is unique and no wavelength other than the free wavelength is assigned.

(2) When the subscriber device 40 connected via a different multiplex communication transmission line 90 before and after the wavelength change of the subscriber device 40a-2 becomes the communication destination, the wavelength used before the wavelength change is reused as it is. It is available. However, although the wavelength is used as the destination information, for example, when passing through different transmission paths or when the input port or output port of the optical switch is different, the same wavelength is treated as a different path. In order to enable reuse as described above, in this case, for example, an "input transmission line" or "output transmission line" or "path" is configured as an argument as a condition for determining the output destination of the optical signal. "Combination of all transmission lines" is added. For example, it is output by a combination of a transmission line or port into which an optical signal is input and a wavelength of an optical signal, or a combination of a transmission line or port in which an optical signal is input and a subscriber device 40 which has transmitted an optical signal and a wavelength of the optical signal. The destination is decided.

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 uplink multicast. 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 from the port 11-2 to which the return transmission line is connected, and another optical signal transmitted through the return transmission line. Input from 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 an optical signal distributed by a 1 × N power splitter 71 from a plurality of ports 11-1, and one of the input optical signals is sent to the port 11-2 connected to the ground B by another one. Two optical signals are output to port 11-2 connected to ground C.

The subscriber device 40 may output a WDM signal. For example, the subscriber device 40 outputs a WDM signal in which an optical signal having a wavelength λ ₁ and an optical signal having a wavelength λ ₂ are multiplexed. The plurality of transmission lines between the WDM device 80b and the optical SW10f transmit and receive optical signals having wavelengths λ ₁ , λ ₂ , ... In order from the top. Similarly, in the plurality of transmission lines between the WDM device 80c and the optical SW10f, optical signals having wavelengths λ ₁ , λ ₂ , ... Are transmitted and received in order from the top.

The optical SW10f distributes the WDM signals of the wavelength λ ₁ and the wavelength λ ₂ input from the port 11-1 connected to the subscriber device 40 by the distribution unit 58. The optical SW10f outputs the distributed WDM signal to the port 11-2 corresponding to the wavelength λ ₁ among the ports 11-2 connected to the WDM device 80b. Further, the optical _SW10f outputs another distributed WDM signal to the port 11-2 corresponding to the wavelength λ2 among the ports 11-2 connected to the WDM device 80c. The WDM device 80b filters the WDM signal input from the port corresponding to the wavelength λ ₁ to block the wavelength λ ₂ , passes the optical signal of the wavelength λ ₁ , and outputs the signal to the multiplexing communication transmission line 90. The WDM device 80c filters the WDM signal input from the port corresponding to the wavelength λ ₂ to block the wavelength λ ₁ , passes the optical signal of the wavelength λ ₂ , and outputs the signal to the multiplexing communication transmission line 90.

FIG. 10 is a diagram showing a case where the optical SW10f performs uplink 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 having a wavelength λ ₁ , and the subscriber device 40a-1-2 transmits an optical signal having a wavelength λ ₂ . The optical SW10f is a port 11 of 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 an optical signal distributed by the 1 × N power splitter 71 from a plurality of ports 11-1.

The optical SW10f transfers 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 uses the optical signal distributed by the power splitter 71 as 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. The WDM device 80b filters the optical signal input from the port corresponding to the wavelength λ ₁ and passes the optical signal of the wavelength λ ₁ to output to the multiplexing communication transmission line 90, and inputs the optical signal from the port corresponding to the wavelength λ 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. Similarly, the WDM device 80c filters the optical signal input from the port corresponding to the wavelength λ ₁ and passes the optical signal of the wavelength λ ₁ to output to the multiplexing communication transmission line 90, and the port corresponding to the wavelength λ ₂ The optical signal input from is filtered, the optical signal having the wavelength λ ₂ is passed, and the optical signal is output to the multiplexing communication transmission line 90.

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

FIG. 12 is a diagram showing a case where the optical SW 10g performs WDM transmission and downlink multicast. The difference between the connection configuration shown in FIG. 12 and the connection configuration shown in FIG. 11 is that they are connected to a plurality of ports 11-1 instead of the WDM device 80 connected to the plurality of ports 11-2 of the optical SW 10g. This is the point where the WDM device 81 is arranged. One or more subscriber devices 40 are connected to the WDM device 81 on the opposite side of the port 11-1. The optical SW10g inputs an optical signal having a plurality of wavelengths from another ground from the port 11-2, and outputs the optical signal to the port 11-1 to which the folded transmission line of the distribution unit 59 is connected. The optical signal having a plurality of wavelengths is branched as it is by the power splitter 72. The optical SW10d inputs a branched optical signal having a plurality of wavelengths from a plurality of ports 11-2, and outputs the input optical signal to any port 11-1 connected to the WDM device 81. The WDM device 81 filters and passes an optical signal having a wavelength corresponding to the port 11-1 to which the optical signal is input from the input optical signal having a plurality of wavelengths, and the passed optical signal is connected to the subscriber device 40. Output to the transmission line.

FIG. 13 is a diagram showing a configuration example of an optical SW10h that electrically processes an optical signal. In FIG. 13, the same parts as those of the optical SW10b shown in FIG. 3 are designated by the same reference numerals, and the description thereof will be omitted. The difference between the optical SW10h and the above-mentioned optical SW10a to 10g is that the optical SW10h is further provided with the port 12-1 and the port 12-2. Ports 12-1 and 12-2 are connected to the electric processing unit 84 via the transmission line 52. Ports 11-1 and 11-2 may be used as ports connected to the electric processing unit 84 via the transmission line 52.

In the optical SW10h, according to the control of the optical SW control unit 26, the optical signal input from the subscriber device 40 is combined with the subscriber device 40 from which the optical signal is transmitted or the port 11-1 into which the optical signal is input and the wavelength. Output from port 11-2 or port 12-1 accordingly. According to the control of the optical SW control unit 26, the optical SW10h sets the output destination of the optical signal input from the port 11-2 to the port 11-1 or the output destination of the optical signal depending on the combination of the port 11-2 to which the optical signal is input and the wavelength. Output from port 12-1.

The optical SW10h drops an optical signal to the electric processing unit 84 by outputting an optical signal from the port 12-1. The electric processing unit 84 electrically terminates the dropped optical signal, performs various electric processing such as error correction and line concentrating, converts it into an optical signal, and inputs it to the port 12-2 of the optical SW10h. The optical SW10h transmits the optical signal input from the electric processing unit 84 from the port 11-1 or the port 11-2 according to the transfer destination on the path to the communication destination specified by the combination of the port 12-2 and the wavelength. Output. In this way, the electric processing unit 84 performs OE (addition of electric treatment) -O conversion (O represents light and E represents electricity). The electric processing unit 84 may simply perform O-EO conversion without performing electric processing for adding a function. The electric processing unit 84 performs 3R reproduction (Re-amplification: amplification, Re-timing: timing reproduction, Re-shaping: waveform shaping) at the time of O-EO conversion or the like, or inverts 0/1 to a threshold value. By using the effect, it is possible to reduce the deterioration of the optical waveform due to transmission.

The wavelength of the optical signal before being converted into an electric signal and the wavelength of the optical signal after being converted from the electric signal may be the same or different. The electric processing unit 84 multiplexes the optical signals transmitted from the plurality of subscriber devices 40 in the electric stage, converts the multiplexed signals into a plurality of optical signals, and separates ports, duplexers, and power splitters. You may branch to. The branched optical signal may be further branched and output to the duplexer at a plurality of wavelengths, or may be further branched by a power splitter and multicast. The electric processing unit 84 may be multiplexed or only multicast in the electric stage. The processing in the electric stage is suitable when the band is small with respect to the transmission line, for example, when the signals of the transmitter / receiver of the subscriber device 40 are bundled and handled.

Specifically, the optical SW10h converts optical signals transmitted from each of the plurality of subscriber devices 40 into electrical signals, multiplexes them, processes the multiplexed electrical signals, and then converts them into optical signals having a plurality of wavelengths. It is connected to the electric processing unit 84 that is converted and input to the optical switch 10h. The optical switch control unit 26 receives a plurality of optical signals input from the transmission path 50-1 according to a combination of a plurality of subscriber devices 40 transmitting the input plurality of optical signals and a wavelength of the input optical signal. The optical switch 10h is controlled so as to output to the electric processing unit 84 and output the signal input from the electric processing unit 84 to the transmission path 50-2 according to the transfer destination on the path to the communication destination specified by the wavelength. do.

When the port to be the output destination of the optical SW is determined by the combination of the subscriber device for transmitting the optical signal and the wavelength, the direction from the port 11-1 to the port 11-2 in order to pass through the electric processing unit 84. And the direction from port 11-2 to port 11-1, the destination may be different.

The electric processing unit 84 has an O / E (optical / electric) conversion unit 85, a processing execution unit 86, an E / O (electrical / optical) conversion unit 87, and a storage unit 88. The O / E conversion unit 85 converts the optical signal input from the optical SW10h into an electric signal. The processing execution unit 86 includes a processor 861 and an accelerator 862. The processor 861 is a general-purpose processor such as a CPU (central processing unit). The accelerator 862 is, for example, a processor such as a GPU (Graphics Processing Unit). The processor 861 and the accelerator 862 read a program from the storage unit 88 and execute the program to perform electrical signal processing on the electrical signal converted by the O / E conversion unit 85. The processing execution unit 86 may perform electrical signal processing of a plurality of functions. Examples of electrical signal processing include DSP (Digital Signal Processing) for long-distance / high-speed access, mobile fronthaul processing, error correction, and the like. The E / O conversion unit 87 converts the electric signal into an optical signal having a wavelength specified by the optical SW control unit 26, and outputs the electric signal to the optical SW 10h. The storage unit 88 stores a program for the processor 861 and the accelerator 862 to execute the function of electrical signal processing.

By making the processing execution unit 86 a device architecture based on a general-purpose processor, it is possible to add and change electrical signal processing, and it is also possible to replace it with various functions other than the transmission function. By performing DSP for long-distance / high-speed access, the processing execution unit 86 eliminates the need for a dedicated LSI (Large-Scale Integration, large-scale integrated circuit) for long-distance / high-speed access, and has flexible functions according to needs. Deployment can be realized.

The optical SW10h may be connected to a plurality of electric processing units 84. In this case, the optical SW10h has ports 12-1 and 12-2 connected to each electric processing unit 84. Each of the electric processing units 84 may perform different electric signal processing, or a part or all of them may perform the same electric processing.

The processing execution unit 86 and the storage unit 88 may be realized by using hardware such as an ASIC (Application Specific Integrated Circuit), a PLD (Programmable Logic Device), or an FPGA (Field Programmable Gate Array).

FIG. 14 is a diagram showing an example of connection using the optical SW10h. The subscriber devices 40-1, 40-2, 40-3 connected to the optical SW10h are, for example, ONUs. The user 46-1 who uses the subscriber device 40-1 is a user who performs long-distance or high-speed communication. One or more communication devices of user 46-1 are connected to the subscriber device 40-1. The subscriber device 40-1 communicates with the communication destination device by the long-distance line P1. The mobile base station 46-2 is connected to the subscriber device 40-2. In FIG. 14, a plurality of subscriber devices 40-2 are connected to one transmission line 50-1 by a power splitter 55. The subscriber device 40-2 communicates with the communication destination device by the medium-distance line P2. The user 46-3 who uses the subscriber device 40-3 is a user who performs medium-distance or medium-speed communication. One or more communication devices of the user 46-3 communicate with the communication destination device by the medium-distance line P3 via the subscriber device 40-3. The optical signals of the long-distance line P1, the medium-distance line P2, and the medium-distance line P3 are wavelength-multiplexed and transmitted through the multiplex communication transmission line 90 connected to the core NW (network). The electric processing unit 84 has a DSP function for long-distance / high-speed access, a mobile front hole processing function, an error correction function, and the like.

The operation of the optical SW10h will be described with reference to FIGS. 13 and 14. The optical SW10h outputs an upstream optical signal transmitted by the subscriber device 40-1 to the electric processing unit 84. The O / E conversion unit 85 of the electric processing unit 84 converts the input optical signal into an electric signal. The processing execution unit 86 performs DSP processing for long-distance / high-speed access on the converted electric signal. The E / O conversion unit 87 converts the DSP-processed electrical signal into an optical signal and outputs it to the optical SW10h. The wavelength after conversion may be the same as or different from the wavelength at the time of input to the electric processing unit 84. The optical SW10h outputs an optical signal input from the electric processing unit 84 to the multiplex communication transmission line 90 from the port 11-2.

Further, the optical SW10h inputs a downlink optical signal addressed to the subscriber device 40-1 that has transmitted the multiplex communication transmission line 90. The optical SW10h outputs the input downlink optical signal from the port 12-1 to the electric processing unit 84 according to the combination of the input port 51-2 and the wavelength. The O / E conversion unit 85 of the electric processing unit 84 converts the input optical signal into an electric signal, and the processing execution unit 86 performs DSP processing for long-distance / high-speed access on the converted electric signal. .. The E / O conversion unit 87 converts the DSP-processed electrical signal into an optical signal and outputs it to the optical SW10h. The wavelength after conversion of the optical signal may be the same as or different from the wavelength when it is input to the electric processing unit 84. The optical SW10h outputs an optical signal input from the electric processing unit 84 to the port 11-1 connected to the subscriber device 40-1.

In the above example, the electric processing unit 84 shows a configuration in which a multiplexed electric signal is modulated by the same signal and converted into an optical signal having a plurality of wavelengths. The electrical processing unit 84 may be configured to convert a multiplexed or multiplexed electrical signal into one or more optical signals having one or more wavelengths (optical signals modulated by the same signal or different signals). ..

The optical signals transmitted and received by the subscriber device 40-2 are also processed in the same manner as the optical signals transmitted and received by the subscriber device 40-1 described above. However, the processing execution unit 86 performs mobile front-hole processing on the optical signals transmitted and received by the subscriber device 40-2. The processing execution unit 86 determines the signal processing to be performed on the electric signal based on arbitrary information contained in the electric signal.

On the other hand, the optical SW10h outputs the upstream optical signal input from the subscriber device 40-3 from the port 11-2 to the multiplex communication transmission line 90. Further, the optical SW10h inputs a downlink optical signal addressed to the subscriber device 40-3 that has transmitted the multiplex communication transmission line 90, and joins according to the combination of the port 11-2 to which the optical signal is input and the wavelength. Output to port 11-1 connected to the device 40-3.

FIG. 15 is a diagram showing a configuration example of an optical SW10i that monitors an optical signal before performing WDM transmission. In the figure, the same parts as those of the optical SW10e shown in FIG. 6 are designated by the same reference numerals, and the description thereof will be omitted. The difference from FIG. 6 is that a monitoring unit 60 is provided between the port 11-2 and the WDM device 80. The transmission line 50-2 connected to the port 11-2 is provided with a monitoring unit 60. In the figure, only three monitoring units 60 are shown. The specific configuration of the monitoring unit 60 is as shown in FIG. The optical signal output from the port 11-2 is combined and output by the WDM device 80 via the monitoring unit 60. 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 signals to the monitoring unit 60, respectively. The monitoring unit 60 generates monitoring information based on the monitoring result and outputs the generated monitoring information. As the output destination of the monitoring information, for example, the control unit 20 may be mentioned.

Subsequently, the access topology to the optical SW will be described with reference to FIGS. 16 to 25.

FIG. 16 is a diagram showing a PDS (Passive Double Star) type access topology using time division multiplexing. As the optical SW1001, the above-mentioned optical SW10a to 10i can be used. The optical SW1001 has ports 11-1-1 to 11-1-P and ports 11-2-1 to 11-2-Q. The transmission line 50-1 connected to port 11-1-p (p is an integer of 1 or more and P or less) is also described as transmission line 50-1-p, and port 11-2-q (q is 1 or more and Q). The transmission line 50-2 connected to the following integer) is also referred to as a transmission line 50-2-q. In FIG. 16, port 11-2-q is connected to ground # q by a transmission line 50-2-q.

A power splitter 56 is provided on the transmission line 50-1-p. A subscriber device 40-p in the Np range (Np is an integer of 2 or more) is connected to the power splitter 56 in a star shape. The Np subscriber device 40-p is described as the subscriber device 40-p-1 to 40-p-Np, and the subscriber device 40-p-np (np is an integer of 1 or more and Np or less). The transmission line 50-1-p to and from the power splitter 56 is referred to as 50-1-p-np. Subscriber devices 40-p-1 to 40-p-Np utilize the same wavelength by time division multiplexing. The wavelength used for the uplink optical signal and the wavelength used for the downlink optical signal are different.

The optical SW1001 inputs a downlink optical signal having a wavelength λ ₁ addressed to each of the subscriber devices 40-p-1 to 40-p-Np time-division-multiplexed from the port 11-2-q. The optical SW1001 outputs the input downlink optical signal from the output destination port 11-1-p according to the combination of the port 11-2 _- q and the wavelength λ1. The power splitter 56 inputs a time-division-multiplexed downlink optical signal from the transmission line 50-1-p, branches the input optical signal, and transmits the transmission lines 50-1-p-1 to 50-1-p-. Output to Np. The subscriber devices 40-p-1 to 40-p-Np receive the time-division-multiplexed optical signal, and select a downlink optical signal addressed to the own device from the received optical signal.

The subscriber devices 40-p-1 to 40-p-Np transmit time-division-multiplexed upstream optical signals of the same wavelength λ ₂ by TDMA (time-division multiple access). The power splitter 56 inputs an upstream optical signal having a wavelength of λ ₂ from each of the transmission lines 50-1-p-1 to 50-1-p-Np, and the input optical signal is time-division-multiplexed to perform time-division multiplexing. Output to 1-p. The optical SW1001 outputs a time-division-multiplexed upstream optical signal from the port 11-2-q corresponding to the combination of the port 11-1-p and the wavelength λ ₂ .

The PDS type access topology can be applied to any one or more of the transmission lines 50-1-1 to 50-1-P.

FIG. 17 is a diagram showing a PDS type access topology using wavelength division multiplexing. As the optical SW1002, the above-mentioned optical SW10a to 10i can be used. The optical SW1002 is connected to one or more WDM devices 81. The WDM device 81 combines downlink optical signals of different wavelengths output from each of the plurality of ports 11-1 and outputs them to the multiplexing communication transmission line 91. The WDM device 81 demultiplexes the upstream wavelength division multiplexing optical signal received via the multiplex communication transmission line 91, and inputs the demultiplexed optical signals to different ports 11-1. A power splitter 56 is provided in the multiplex communication transmission line 91. N subscriber devices (N is an integer of 2 or more) are connected to the power splitter 56 in a star shape. The subscriber device 40 and the power splitter 56 are connected by a transmission line 92. The plurality of subscriber devices 40 connected to the power splitter 56 transmit and receive optical signals having different wavelengths.

In FIG. 17, ports 11-1-p to 11-1- (p + N) of the optical SW1002 are connected to the WDM device 81 via the transmission line 50-1 (p and N are integers of 1 or more, p + N). Is an integer less than or equal to P). Subscriber devices 40-p to 40- (p + N) are connected to the power splitter 56.

The optical SW1002 inputs a downlink optical signal from port 11-2- (q + n) to the subscriber device 40- (p + n) having a wavelength of λ _{1 (q + n)} (q is an integer of 1 or more, n is 0 or more N). The following integers). FIG. 17 is an example in the case of q = 1. The optical SW1002 is an output destination in which the downlink optical signal of the wavelength λ _{1 (1 + n)} input from the port 11-2- (q + n) is combined with the port 11-2- (q + n) and the wavelength λ _{1 (1 + n)} . Route to port 11-1- (p + n) of. As a result, the optical SW1002 routes the downlink optical signal of wavelength λ ₁₁ input from port 11-2-1 to port 11-1-p, and downlinks the wavelength λ ₁₂ input from port 11-2-2. Route the optical signal to port 11-1- (p + 1).

The WDM device 81 combines the downlink optical signals of wavelengths λ ₁₁ to λ _1N output from each of the ports 11-1-p to 11-1- (p + N) and outputs them to the multiplexing communication transmission line 91. The power splitter 56 inputs a downlink optical signal whose wavelength is multiplexed from the multiplex communication transmission line 91, branches the input downlink optical signal as it is, and is connected to each of the subscriber devices 40-p to 40- (p + N). Is output to the transmission line 92 of. The subscriber devices 40-p to 40- (p + N) receive the wavelength-multiplexed downlink optical signal, and select the downlink optical signal having the wavelength used by the own device from the received optical signal.

The subscriber device 40- (p + n) transmits an upstream optical signal having a wavelength of λ _{2 (1 + n)} . The power splitter 56 inputs an upstream optical signal from each of the subscriber devices 40-p to 40- (p + N) via the transmission line 92, and the input wavelengths λ ₂₁ to λ _{2 (1 + N)} each upstream optical signal. The signal is wavelength-multiplexed and output to the multiplex communication transmission line 91. The WDM device 81 inputs an upstream optical signal wavelength-multiplexed from the multiplex communication transmission line 91 and separates the wavelengths. The WDM device 81 inputs upstream optical signals having a wavelength of λ _{2 (1 + n)} to ports 11-1- (p + n), respectively. The optical SW1002 outputs an optical signal having an upstream wavelength λ ₂ (1 + n) according to the combination of the input port 11-1- (p + n) and the wavelength λ _{2 (1 + n)} to the output destination port 11-2- ( Output from q + n). As a result, the upstream optical signal of wavelength λ ₂₁ transmitted by the subscriber device 40-p is input from port 11-1-p and output from port 11-2-1. The upstream optical signal of wavelength λ ₂₂ transmitted by the subscriber device 40- (p + 1) is input from port 11-1- (p + 1) and output from port 11-2-2. As shown in FIG. 18, the WDM device may be placed after the optical SW.

FIG. 18 is a diagram showing a PDS type access topology using wavelength division multiplexing and placing a WDM device after the optical SW. As the optical SW1003, the above-mentioned optical SW10a to 10i can be used. The port 11-2-q of the optical SW1003 (q is an integer of 1 or more and Q or less) is connected to the WDM device 97 via the transmission line 50-2-q. The WDM device 97 is connected to ground #n (n is an integer of 1 or more and N or less) via a transmission line 50-2-q-n. A power splitter 56 is provided in the transmission line 50-1-p connected to the port 11-1-p of the optical SW1003. N subscriber devices 40-p-1 to 40-p-N are connected to the power splitter 56 in a star shape.

The WDM device 97 inputs a downlink optical signal transmitted from the ground #n to the subscriber device 40-pn having a wavelength λ _1n from the transmission line 50-2-q-n. The WDM device 97 inputs to the optical SW 1003 a wavelength division multiplexing signal that multiplexes the downlink optical signals of λ ₁₁ to λ _1N input from each of the ground # 1 to the ground # N. The optical SW1003 outputs the downlink wavelength division multiplexing signal input from the port 11-2-q from the output destination port 11-1-p. The power splitter 56 branches the wavelength division multiplexing signal input from the transmission line 50-1-p and outputs it to the transmission lines 50-1-p-1 to 50-1-p-N. The subscriber devices 40-p-1 to 40-p-N receive the wavelength division multiplexing signal and select a downlink optical signal addressed to the own device from the received optical signal. As a result, the subscriber device 40-pn receives an optical signal having a wavelength of λ _1n from the ground #n.

The subscriber device 40-pn transmits an upstream optical signal having a wavelength of λ _2n . The power splitter 56 is used to ascend the wavelengths λ ₂₁ to λ _2N from each of the subscriber devices 40-p-1 to 40-p-N via the transmission lines 50-1-p-1 to 50-1-p-N. Input the optical signal of. The power splitter 56 outputs a wavelength division multiplexing signal in which the upstream optical signals having wavelengths λ ₂₁ to λ _2N are wavelength-multiplexed to the transmission line 50-1-p. The optical SW1003 inputs a wavelength division multiplexing signal in which upstream optical signals having wavelengths λ ₂₁ to λ _2N are wavelength-multiplexed from port 11-1-p. The optical SW1003 outputs an upstream wavelength division multiplexing signal from the output destination port 11-2-q to the transmission line 50-2-q. The WDM device 97 inputs an upstream optical signal wavelength-multiplexed from the transmission line 50-2-q and separates the wavelengths. The WDM device 97 outputs an upstream optical signal having a wavelength of λ _2n to a transmission line 50-2-n connected to ground #n. As a result, the optical signal having the wavelength λ _2n transmitted by the subscriber device 40-pn is transmitted to the ground #n.

FIG. 19 is a diagram showing a bus-type access topology using time division multiplexing. As the optical SW1004, the above-mentioned optical SW10a to 10i can be used. The access topology shown in FIG. 19 is different from the access topology shown in FIG. 16 in that a plurality of subscriber devices 40-p-1 to 40-p-Np are connected to the transmission line 50-1-p in a bus type. It is a point. One or more power splitters 55 are provided on the transmission line 50-1-p. The power splitter 55 to which the subscriber device 40-pn (n is an integer of 1 or more and Np-1 or less) is connected is referred to as a power splitter 55-n.

Subscriber devices 40-p-1 to 40-p-Np utilize the same wavelength by time division multiplexing. The wavelength used for the uplink optical signal and the wavelength used for the downlink optical signal are different. The transmission line 50-2-1 connected to the ground # 1 transmits a time-division-multiplexed downlink optical signal of wavelength λ ₁ addressed to each of the subscriber devices 40-p-1 to 40-p-Np. The optical SW1004 inputs a downlink optical signal having a wavelength λ ₁ that is time-division-multiplexed and transmitted through the transmission line 50-2-1 from the port 11-2-1. The optical SW1004 routes the input downlink optical signal to the output destination port 11-1-p according to the combination of the port 11-2-1 (or ground # ₁ ) and the wavelength λ1. The optical SW1004 outputs a time-division-multiplexed downlink optical signal having a wavelength λ ₁ from the port 11-1-p to the transmission line 50-1-p. The power splitter 55-n branches the time-division-multiplexed downlink optical signal from the transmission line 50-1-p, and outputs the branched downlink optical signal to the subscriber device 40-pn. The subscriber devices 40-p-1 to 40-p-Np receive the time-division-multiplexed downlink optical signal, and select the downlink optical signal addressed to the own device from the received downlink optical signal.

The subscriber devices 40-p-1 to 40-p-Np transmit time-division-multiplexed upstream optical signals of the same wavelength λ ₂ by TDMA. Each power splitter 55-n time-division-multiplexes the upstream optical signal of wavelength λ ₂ input from the subscriber device 40-pn with the upstream optical signal transmitted through the transmission line 50-1-p. The optical SW1004 inputs a time-division-multiplexed upstream optical signal from port 11-1-p, and outputs the time-division-multiplexed upstream optical signal to port 11-2-1 according to the combination of port 11-1-p and wavelength λ ₂ . It is routed and output to the transmission line 50-2-1 connected to the ground # 1.

Note that the bus-type access topology can be applied to any one or more of the transmission lines 50-1-1 to 50-1-P.

FIG. 20 is a diagram showing a bus-type access topology using wavelength division multiplexing. As the optical SW1005, the above-mentioned optical SW10a to 10i can be used. The access topology shown in FIG. 19 differs from the access topology shown in FIG. 17 in that a plurality of subscriber devices 40-p to 40- (p + N) are connected to the multiplex communication transmission line 91 in a bus type. be. The subscriber devices 40-p to 40- (p + N) transmit and receive optical signals having different wavelengths. The multiplex communication transmission line 91 is provided with one or more power splitters 55. The power splitter 55 to which the subscriber device 40- (p + n) (n is an integer of 0 or more and N-1 or less and N is an integer of 1 or more) is connected is referred to as a power splitter 55- (p + n).

Similar to the optical SW1002 shown in FIG. 17, the optical SW1005 inputs a downlink optical signal from the port 11-2- (q + n) to the subscriber device 40- (p + n) having a wavelength λ _{1 (1 + n)} (q is). An integer of 1 or more, n is an integer of 0 or more and N or less). FIG. 20 is an example in the case of q = 1. The optical SW1005 is an output destination in which the downlink optical signal of the wavelength λ _{1 (1 + n)} input from the port 11-2- (q + n) is combined with the port 11-2- (q + n) and the wavelength λ _{1 (1 + n)} . Route to port 11-1- (p + n) of.

The WDM device 81 combines the downlink optical signals of wavelengths λ ₁₁ to λ _1N output from each of the ports 11-1-p to 11-1- (p + N) and outputs them to the multiplexing communication transmission line 91. The power splitter 55- (p + n) branches the wavelength-multiplexed downlink optical signal from the multiplex communication transmission line 91, and outputs the branched downlink optical signal to the subscriber device 40- (p + n). The subscriber devices 40-p to 40- (p + N) receive the wavelength-multiplexed downlink optical signal, and select the downlink optical signal addressed to the own device from the received downlink optical signal.

The subscriber device 40- (p + n) transmits an upstream optical signal with a wavelength of λ _{2 (1 + n)} . Each power splitter 55- (p + n) has a wavelength λ _{2 (1 +} n) input from the subscriber device 40- (p + n) to an optical signal having an upstream wavelength λ _{2 (2 + n)} to λ _2N transmitted through the multiplex communication transmission line 91. ₎ To combine the upstream optical signals. The WDM device 81 inputs an upstream optical signal wavelength-multiplexed from the multiplex communication transmission line 91 and separates it into an upstream optical signal having wavelengths λ ₂₁ to λ _2N . The WDM device 81 inputs an upstream optical signal having a wavelength of λ _{2 (1 + n)} to port 11-1- (p + n). Similar to the optical SW1002 shown in FIG. 16, the optical SW1005 receives an upstream optical signal having a wavelength λ ₂ (1 + n) according to the combination of the input port 11-1- (p + n) and the wavelength λ _{2 (1 + n)} . Output from the output destination port 11-2- (q + n). As a result, the upstream optical signal of wavelength λ ₂₁ transmitted by the subscriber device 40-p is input from port 11-1-p and output from port 11-2-1. The upstream optical signal of wavelength λ ₂₂ transmitted by the subscriber device 40- (p + 1) is input from port 11-1- (p + 1) and output from port 11-2-2. As shown in FIG. 21, the WDM device may be placed after the optical SW.

FIG. 21 is a diagram showing a bus-type access topology using wavelength division multiplexing and placing a WDM device after the optical SW. As the optical SW1006, the above-mentioned optical SW10a to 10i can be used. In FIG. 21, the same parts as those in FIG. 18 are designated by the same reference numerals. The port 11-2-q of the optical SW1006 (q is an integer of 1 or more and Q or less) is connected to the WDM device 97 via the transmission line 50-2-q. The WDM device 97 is connected to ground #n (n is an integer of 1 or more and N or less, N is an integer of 2 or more) via a transmission line 50-2-q-n. A power splitter 55 of 1 or more is provided in the transmission line 50-1-p connected to the port 11-1-p of the optical SW1006 (p is an integer of 1 or more and P or less). The power splitter 55 to which the subscriber device 40-pn is connected is referred to as a power splitter 55-n.

The WDM device 97 inputs a downlink optical signal transmitted from the ground #n to the subscriber device 40-pn having a wavelength λ _1n from the transmission line 50-2-q-n. The WDM device 97 inputs to the optical SW 1006 a wavelength division multiplexing signal multiplexed with downlink optical signals having wavelengths λ ₁₁ to λ _1N input from each of ground # 1 to ground # N. The optical SW1006 outputs the downlink wavelength division multiplexing signal input from the port 11-2-q from the output destination port 11-1-p. The power splitter 55-n branches the downlink wavelength division multiplexing signal from the transmission line 50-1-p, and outputs the branched downlink wavelength division multiplexing signal to the subscriber device 40-pn. The subscriber devices 40-p-1 to 40-p-N select a downlink optical signal addressed to the own device from the received downlink wavelength division multiplexing signal. As a result, the subscriber device 40-pn receives an optical signal having a wavelength of λ _1n from the ground #n.

The subscriber device 40-pn transmits an upstream optical signal having a wavelength of λ _2n . Each power splitter 55-n wavelength-multiplexes the upstream optical signal of the wavelength λ _2n input from the subscriber device 40-pn with the upstream optical signal transmitted through the transmission line 50-1-p. The optical SW1006 inputs a wavelength division multiplexing signal in which upstream optical signals having wavelengths λ ₂₁ to λ _2N are wavelength-multiplexed from port 11-1-p. The optical SW1006 outputs an upstream wavelength division multiplexing signal from the output destination port 11-2-q to the transmission line 50-2-q. The WDM device 97 inputs a wavelength division multiplexing signal from the transmission line 50-2-q and separates the wavelengths. The WDM device 97 outputs an upstream optical signal having a wavelength of λ _2n to a transmission line 50-2-q-n connected to ground #n. As a result, the optical signal having the wavelength λ _2n transmitted by the subscriber device 40-pn is transmitted to the ground #n.

FIG. 22 is a diagram showing a loop type access topology. As the optical SW1007, the above-mentioned optical SW10a to 10i can be used. Some ports 11-1-p1 to 11-1-pN of the optical SW1007 (p1 <pN, p1 is an integer of 1 or more, pN is an integer of P or less) are WDM access rings that transmit optical signals of multiple wavelengths. Connected to network 31. Optical signals of several wavelengths used in the WDM access ring network 31 are transmitted to the subscriber device 40 of the communication destination or the upper NW via the optical SW1007. In the topology shown in FIG. 22, the WDM duplexer is not used, and the subscriber devices 40 facing each other are connected by two transmission lines for communication.

The WDM access ring network 31 is a network in which R units of Add / Drop nodes 32 are connected by a transmission line 53. FIG. 21 is an example of R = 4. R units of Add / Drop node 32 are described as Add / Drop node 32-1 to 32-R, and Add / Drop node 32-r (r is an integer of 1 or more and R or less) and Add / Drop node 32- (r + 1). ) Is referred to as a transmission line 53-r. However, the Add / Drop node 32- (R + 1) is regarded as the Add / Drop node 32-1. The Add / Drop node 32-1 is connected to the port 11-1-pn of the optical SW1007 (pn is an integer of p1 or more and pN or less) via the transmission line 50-1-pn.

The Add / Drop node 32 has a demultiplexing unit 33, an optical SW 34, and a combine unit 35. The demultiplexing unit 33 of the Add / Drop node 32-r (r is an integer of 2 or more and R or less) demultiplexes the wavelength division multiplexing optical signal input from the transmission line 53- (r-1), and is obtained by demultiplexing. The optical signal is output to the optical SW34. The optical SW 34 is connected to one or more subscriber devices 40. The figure shows only one subscriber device 40 connected to the optical SW34. The optical SW 34 drops an optical signal having a wavelength corresponding to its own node among the optical signals input from the demultiplexing unit 33. The optical receiver 43 of the subscriber device 40 receives the optical signal dropped by the optical SW 34. The optical SW 34 inputs an optical signal transmitted by the optical transmitter 42 of the subscriber device 40, and outputs the input optical signal and the optical signal that has not been dropped to the combine unit 35. The combine section 35 of the Add / Drop node 32-r combines the optical signal input from the optical SW34 and outputs it to the transmission line 53-r. The optical SW34 of the Add / Drop node 32-1 drops an optical signal having a wavelength corresponding to its own node among the optical signals demultiplexed by the demultiplexing unit 33, and transmits the optical signal of each wavelength to the transmission path 50-1. -Enter in pn ₁ (pn ₁ = 1, 3, 5, ..., P (N-1)). Port 11-1-pn ₁ of the optical SW 1007 inputs the optical signal dropped by the Add / Drop node 32-1 from the transmission line 50-1-pn ₁ . The optical SW34 of the Add / Drop node 32-1 transmits an optical signal output by the optical SW1007 from the port 11-1-pn ₂ (pn ₂ = 2, 4, 6, ..., PN) in the transmission line 50-1-pn ₂ . The input optical signal and the optical signal that did not drop are output to the combine section 35.

As a result, it is connected to ONU # 1, which is a subscriber device 40 connected to the Add / Drop node 32-4 of the WDM access ring network 31, and to ports 11-2-1 and 11-2-2 of the optical SW1007. Communicates with ONU # 2, which is the subscriber device 40, as follows.

ONU # 1 transmits an optical signal having a wavelength of λ ₁ to the Add / Drop node 32-4. The combine section 35 of the Add / Drop node 32-4 combines the optical signal of the wavelength λ ₁ input by the optical SW34 and the optical signal not dropped by the optical SW 34 into the Add / Drop node 32-1. Output. The optical SW 34 of the Add / Drop node 32-1 drops an optical signal having a wavelength λ ₁ demultiplexed by the demultiplexing unit 33, and outputs the undropped optical signal to the demultiplexing unit 35. Port 11-1-p1 of the optical SW1007 inputs an optical signal having _a wavelength λ1 dropped by the Add / Drop node 32-1 from the transmission line 50-1-p1. The optical SW1007 outputs an optical signal having _a wavelength λ1 input from the port 11-1-p1 from the port 11-2-1. The optical receiver 43 of ONU # 2 receives an optical signal having a wavelength λ ₁ transmitted through the transmission line 50-2-1.

The optical transmitter 42 of ONU # 2 transmits a downlink optical signal having a wavelength of λ ₂ . Port 11-2-2 of the optical SW1007 inputs the optical signal transmitted by ONU # 2 from the transmission line 50-2-2. The optical SW1007 outputs a downlink optical signal of wavelength λ ₂ input from port 11-2-2 from port 11-1-p2. The optical SW34 of the Add / Drop node 32-1 inputs an optical signal having a wavelength λ ₂ output by the optical SW1007 from the transmission line 50-1-p2, and combines the input optical signal and the non-dropped optical signal. Output to unit 35. The optical signal having the wavelength λ ₂ is input to the Add / Drop node 32-4 via the Add / Drop nodes 32-2 and 32-3. The optical SW34 of the Add / Drop node 32-4 drops an optical signal of wavelength λ ₂ . The optical receiver 43 of the ONU # 1 receives an optical signal having a wavelength λ ₂ dropped by the Add / Drop node 32-4.

FIG. 23 is a diagram showing a loop-type access topology using a WDM duplexer. As the optical SW1008, the above-mentioned optical SW10a to 10i can be used. The access topology shown in FIG. 23 differs from the access topology shown in FIG. 22 in that the optical SW1008 and the WDM access ring network 31 are connected via the WDM device 81 and the WDM device 89.

The Add / Drop node 32-1 of the WDM access ring network 31 and the WDM device 89 are connected by transmission lines 93-1 to 93-N (N is an integer of 2 or more). The WDM device 89 receives an upstream optical signal having a wavelength λ _n1 from a transmission line 93-n ₁ (n ₁ = 1, 3, 5, ..., N-1), and multiplexes the received upstream optical signal. The signal is output to the multiplex communication transmission line 91. The WDM device 89 demultiplexes the downlink wavelength division multiplexing optical signal received via the multiplex communication transmission line 91, and inputs the demultiplexed downlink optical signal having the wavelength λ _n2 to the transmission line 93-n ₂ (n ₂ ). = 2, 4, 6, ..., N).

The WDM device 81 demultiplexes the upstream wavelength division multiplexing optical signal received via the multiplex communication transmission line 91, and inputs the demultiplexed upstream optical signals of the wavelength λ _n1 to ports 11-1-n1 _respectively . The WDM device 81 receives the downlink optical signal of the wavelength λ _n2 output from each of the ports 11-1-pn ₂ , combines the received downlink signal, and outputs the signal to the multiplexing communication transmission line 91.

As a result, it is connected to ONU # 1, which is a subscriber device 40 connected to the Add / Drop node 32-4 of the WDM access ring network 31, and to ports 11-2-1 and 11-2-2 of the optical SW1008. Communicates with ONU # 2, which is the subscriber device 40, as follows. The case of N = 18 will be described as an example.

ONU # 1 transmits an upstream optical signal having a wavelength of λ ₁ to the Add / Drop node 32-4. Another ONU transmits an upstream optical signal having wavelengths λ ₃ and λ ₅ to the Add / Drop node 32-4. The optical SW34 of the Add / Drop node 32-4 inputs an optical signal having wavelengths λ ₁ , λ ₃ , and λ ₅ . The combine section 35 of the Add / Drop node 32-4 combines an optical signal having wavelengths λ ₁ , λ ₃ , and λ ₅ input by the optical SW 34 with an optical signal not dropped by the optical SW 34, and Add / Output to Drop node 32-1. The optical SW34 of the Add / Drop node 32-1 drops the optical signals having wavelengths λ ₁ , λ ₃ , λ ₅ , ... λ ₁₇ demultiplexed by the demultiplexing unit 33, and the undropped optical signal is combined. Output to 35. The WDM device 89 multiplexes the upstream optical signals of wavelengths λ ₁ , λ ₃ , λ ₅ , ... λ ₁₇ input from each of the transmission lines 93-1, 93-3, 93-5, ..., 93-17. The multiplex signal is output to the multiplex communication transmission line 91.

The WDM device 81 inputs an upstream optical signal wavelength-multiplexed from the multiplex communication transmission line 91 and separates the wavelengths. The WDM device 81 outputs the upstream optical signals of the wavelengths λ ₁ , λ ₃ , λ ₅ , ... λ ₁₇ to the ports 111-1-p1, 11-1-p3, 11-1-p5, 11-1-p5 of the optical SW1008, respectively. Enter in 11-1-p17. The optical SW1008 outputs an upstream optical signal having a wavelength λ ₁ from the output destination port 11-2-1. The optical receiver 43 of ONU # 2 receives an optical signal having a wavelength λ ₁ transmitted through the transmission line 50-2-1.

The optical transmitter 42 of ONU # 2 transmits a downlink optical signal having a wavelength of λ ₂ . Port 11-2-2 of the optical SW1008 inputs the optical signal transmitted by ONU # 2 from the transmission line 50-2-2. The optical SW1008 outputs a downlink optical signal having a wavelength λ ₂ input from the port 11-2-2 from the port 11-1-p2. Further, the optical SW1008 transmits the downlink optical signals of the wavelengths λ ₄ , λ ₆ , ..., λ ₁₈ input from the ports 11-2-4, 11-2-6, ..., 11-2-18, respectively. Output from 11-1-p4, 11-2-p6, ..., 11-2-p18.

The WDM device 81 has wavelengths λ ₂ , λ ₄ , λ ₆ , ..., λ output from each of the ports 11-1-p2, 11-1-p4, 11-1-p6, ..., 11-1-p18. A wavelength division multiplexing signal obtained by multiplexing the downlink optical signals of ₁₈ is output to the multiplex communication transmission line 91. The WDM device 89 separates the wavelength division multiplexing signal transmitted through the multiplex communication transmission line 91, and transmits the downlink optical signals of the wavelengths λ ₂ , λ ₄ , λ ₆ , ..., λ ₁₈ obtained by the separation, respectively, to the transmission line 93. Output to -2, 93-4, 93-6, ..., 93-18. The optical SW34 of the Add / Drop node 32-1 transmits optical signals of wavelengths λ ₂ , λ ₄ , λ ₆ , ..., λ ₁₈ output by the WDM device 89 to transmission paths 93-2, 93-4, 93-6, respectively. , ..., Input from 93-18, and output the input optical signal and the optical signal that did not drop to the combiner 35. The combiner 35 combines the optical signal input from the optical SW34 and outputs it to the transmission line 53-1.

The demultiplexing unit 33 of the Add / Drop node 32-2 demultiplexes the optical signal input from the transmission line 53-1 and outputs it to the optical SW34. The optical SW 34 drops optical signals having wavelengths λ ₁₄ , λ ₁₆ , and λ ₁₈ corresponding to its own node. The optical signals having wavelengths λ ₁₄ , λ ₁₆ and λ ₁₈ are transmitted to the optical receiver 43 of the subscriber device 40 corresponding to each wavelength. The optical SW34 of the Add / Drop node 32-2 input an optical signal having wavelengths λ ₁₃ , λ ₁₅ , and λ ₁₇ transmitted by the optical transmitter 42 of each subscriber device 40, and did not drop the input optical signal. The optical signal is output to the combiner 35. The combiner 35 combines the optical signal input from the optical SW34 and outputs it to the transmission line 53-2.

The Add / Drop node 32-3 operates in the same manner as the Add / Drop node 32-2. However, the optical SW34 of the Add / Drop node 32-3 drops the optical signals having wavelengths λ ₈ , λ ₁₀ , and λ ₁₂ corresponding to the own node, and inputs the optical signals having wavelengths λ ₇ , λ ₉ , and λ ₁₁ . .. The demultiplexing unit 33 of the Add / Drop node 32-4 demultiplexes the wavelength division multiplexing optical signal input from the transmission line 53-3 and outputs it to the optical SW34. The optical SW34 of the Add / Drop node 32-4 drops optical signals having wavelengths λ ₂ , λ ₄ , and λ ₆ corresponding to the own node. The optical receiver 43 of the ONU # 1 receives an optical signal having a wavelength λ ₂ dropped by the optical SW 34 of the Add / Drop node 32-4.

FIG. 24 is a diagram showing an access topology that forms one loop on two access planes. As the optical SW1009a and the optical SW1009b, the above-mentioned optical SW10a to 10i can be used. The optical SW1009a and the optical SW1009b are collectively referred to as an optical SW1009. The two ports 11-1 of the optical SW1009 are connected to both ends of one transmission line 54. One or more power splitters 57 are connected to the transmission line 54. The power splitter 57 is connected to the optical transmitter 42 of one or more subscriber devices 40 via the combiner 82 and the optical SW 95, and the optical of one or more subscriber devices 40 via the duplexer 83 and the optical SW 96. It is connected to the receiver 43. Each subscriber device 40 transmits and receives optical signals having different wavelengths.

The transmission line 54 connected to the optical SW1009a is described as a transmission line 54a, and the two ports 11-1 connected to the transmission line 54a are described as ports 11a-1-p1 and 11a-1-p2, and are connected to the optical SW1009b. The transmission line 54 is referred to as a transmission line 54b, and the two ports 11-1 connected to the transmission line 54b are referred to as ports 11b-1-p1 and 11b-1-p2. N power splitters 57 (N is an integer of 1 or more) connected to the transmission line 54a are described as power splitters 57a-1 to 57a-N, and M units (M is 1 or more) connected to the transmission line 54b. The power splitter 57 of (integer) is described as power splitters 57b-1 to 57b-M. The combiner 82 and the demultiplexer 83 connected to the power splitter 57a-n (n is an integer of 1 or more and N or less) are described as the combiner 82a-n and the demultiplexer 83a-n, respectively, and the power splitter 57b. The combiner 82 and the demultiplexer 83 connected to −m (m is an integer of 1 or more and M or less) are referred to as a combiner 82b-m and a demultiplexer 83b-m, respectively. The optical SW95 connected to the combiner 82a-n is referred to as an optical SW95a-n, and the optical SW96 connected to the duplexer 83a-n is referred to as an optical SW96a-n. The optical SW95 connected to the combiner 82b-m is referred to as an optical SW95bm, and the optical SW96 connected to the demultiplexer 83bm is referred to as an optical SW96bm.

The optical SW1009a and the optical SW1009b are connected by a transmission line 54c and a transmission line 54d. Port 11-2 of the optical SW1009a connected to the transmission line 54c is referred to as port 11a-2-q1, and port 11-2 of the optical SW1009a connected to the transmission line 54d is referred to as port 11a-2-q2. Port 11-2 of the optical SW1009b connected to the transmission line 54c is referred to as port 11b-2-q1, and port 11-2 of the optical SW1009b connected to the transmission line 54d is referred to as port 11b-2-q2.

In the above configuration, the optical SW95b-m outputs optical signals of different wavelengths transmitted by the optical transmitter 42 of each subscriber device 40 to the ports corresponding to each wavelength of the combiner 82b-m. The combiner 82b-m inputs optical signals of different wavelengths transmitted by the optical transmitter 42 of each subscriber device 40 via the optical SW95b-m, and combines the input optical signals to generate a wavelength multiplex optical signal. Output. The power splitter 57b-m matches the wavelength division multiplexing optical signal output by the combiner 82bm with the wavelength division multiplexing optical signal transmitted through the transmission line 54b in the direction from the port 11b-1-p2 to the port 11b-1-p1. Wave and output.

Port 11b-1-p1 of the optical SW1009b inputs a wavelength division multiplexing optical signal from the transmission line 54b and outputs it from the port 11b-2-q1. The port 11a-2-q1 of the optical SW1009a inputs the wavelength division multiplexing optical signal output from the port 11b-2-q1 of the optical SW1009b from the transmission line 54c. The optical SW1009a outputs a wavelength division multiplexing optical signal input from the port 11a-2-q1 from the port 11a-1-p1 to the transmission line 54a.

The power splitter 57a-n branches the wavelength division multiplexing optical signal that transmits the transmission path 54a in the direction from the port 11a-1-p1 to the port 11a-1-p2, and the branched wavelength division multiplexing optical signal is the demultiplexer 83a-n. Output to. The demultiplexer 83a-n demultiplexes the wavelength division multiplexing optical signal received from the power splitter 57a-n, and outputs the demultiplexed optical signal to the optical SW96a-n from the port corresponding to the wavelength. The optical SW96a-n outputs an optical signal of each wavelength input from the demultiplexer 83a-n to the optical receiver 43 of the subscriber device 40 that receives the optical signal of that wavelength.

On the other hand, the optical SW95a-n outputs an optical signal to a different wavelength transmitted by the optical transmitter 42 of each subscriber device 40 to a port corresponding to each wavelength of the combiner 82a-n. The combiner 82a-n inputs optical signals of different wavelengths transmitted by the optical transmitter 42 of each subscriber device 40 via the optical SW95an, and combines the input optical signals to generate a wavelength multiplex optical signal. Output. The power splitter 57a-n combines the wavelength division multiplexing optical signal output by the combiner 82a-n with the wavelength division multiplexing optical signal transmitted through the transmission path 54a in the direction from the port 11a-1-p1 to the port 11a-1-p2. Wave and output.

Port 11a-1-p2 of the optical SW1009a inputs a wavelength division multiplexing optical signal from the transmission line 54a and outputs it from the port 11a-2-q2. The port 11b-2-q2 of the optical SW1009b inputs the wavelength division multiplexing optical signal output from the port 11a-2-q2 of the optical SW1009a from the transmission line 54d. The optical SW1009b outputs a wavelength division multiplexing optical signal input from the port 11b-2-q2 from the port 11b-1-p2 to the transmission line 54b.

The power splitter 57b-m branches the wavelength division multiplexing optical signal that transmits the transmission path 54b in the direction from the port 11b-1-p2 to the port 11b-1-p1, and the branched wavelength division multiplexing optical signal is the demultiplexer 83b-m. Output to. The demultiplexer 83b-m demultiplexes the wavelength division multiplexing optical signal received from the power splitter 57b-m, and outputs the demultiplexed optical signal to the optical SW 96b-m from the port corresponding to the wavelength. The optical SW96b-m outputs an optical signal of each wavelength input from the demultiplexer 83b-m to the optical receiver 43 of the subscriber device 40 that receives the optical signal of that wavelength.

Although FIG. 24 shows a case where the optical signal is transmitted counterclockwise, it may be transmitted clockwise, and two left and right cores may be set as a set for redundancy.

FIG. 25 is a diagram showing a line-type access topology. As the optical SW1100, the above-mentioned optical SW10a to 10i can be used. The access topology shown in FIG. 25 differs from the access topology shown in FIG. 16 in that the monitoring unit 60 is connected between the subscriber device 40-p and the optical SW1100. The monitoring unit 60 monitors the optical signal output from the subscriber device 40-p or the optical signal output from the port 11-1-p.

Next, the connection configuration when the number of user connections increases will be described. FIG. 26 is a diagram showing an example in which the scalability of the optical SW is required. FIG. 26 shows N units (N is an integer of 1 or more) optical SW1010-1 to 1010-N. As the optical SW1010-1 to SW1010-N, the above-mentioned optical SW10a to 10i can be used. FIG. 26 shows an example of N = 4. In the figure, ONU # np as the subscriber device 40 is connected to the port 11-1-p of the optical SW1010-n (n is an integer of 1 or more and N or less). The port 11-2-q of the optical SW1010-n is connected to the uplink. The uplink is a transmission line 50-2 connected to the upper network.

When the number of users becomes enormous and the number of ONUs increases, the optical SW1010 may exceed the capacity that can be accommodated. In the present embodiment, even in such a case, the connection configuration as shown in FIG. 27 or FIG. 28 provides the same functions as when the number of users is small, for example, a connection in which an arbitrary uplink is selected, or an arbitrary subscriber. Achieves optical return to the device.

FIG. 27 is a diagram showing an example of optical SW scalability due to a mesh configuration. Some ports 11-1 of the optical SW1010 are connected to the ONU by the transmission line 50-1, and some ports 11-2 are connected to the uplink transmission line 50-2. Further, a part of the ports 11-1 of the optical SW1010 and a part of the ports 11-2 of the other optical SW1010 are connected by a transmission line 50-3. In the figure, one optical SW1010 is connected to all the other optical SW1010s.

The plurality of ports 11-1 of the optical SW1010 are designated as ports 11-1-1, 11-1-2, 11-1-3, ..., 11-1-p1, 11-1-p2, 11-1-p3. Described, the plurality of ports 11-2 of the optical SW1010 are referred to as ports 11-2-1, 11-2-2, 11-2-3, ..., 11-2-q1, 11-2-q2, 11-2. It is described as -q3.

In FIG. 27, ports 11-1-1, 11-1-2, 11-1-3, ... Of the optical SW1010-n (n is an integer of 1 or more and N or less) are ONU # n1, ONU # n2, ONU. Connected to # n3, ..., Ports 11-2-1, 11-2-2, 11-2-3, ... are transmission lines 50 of uplink # n1, uplink # n2, uplink # n3, ... Connected to -2. Further, the optical SW1010-n is connected to the port 11-1 of all the other optical SW1010-j (j ≠ n, j is an integer of 1 or more and N or less) by some ports 11-2. For example, the port 11-2-q1 of the optical SW1010-1 is the port 11-1-p1 of the optical SW1010-2, and the port 11-2-q2 of the optical SW1010-1 is the port 11-1-p1 of the optical SW1010-3. In addition, the port 11-2-q3 of the optical SW1010-1 is connected to the port 11-1-p1 of the optical SW1010-4. The port 11-2-q1 of the optical SW1010-2 is connected to the port 11-1-p1 of the optical SW1010-1, and the port 11-2-q2 of the optical SW1010-2 is connected to the port 11-1-p2 of the optical SW1010-3. The port 11-2-q3 of the optical SW1010-2 is connected to the port 11-1-p2 of the optical SW1010-4. It should be noted that the optical SW1010-n is a port 11 of a part of the optical SW1010-j among all the other optical SW1010-j (j ≠ n, j is an integer of 1 or more and N or less) due to some ports 11-2. You may connect to -1.

For example, when ONU # 11 transmits an upstream optical signal having a wavelength λ ₁ addressed to uplink # 41, the optical SW1010-1 transmits an optical signal input from port 11-1-1 from port 11-2-q3. Output. Port 11-1-p1 of the optical SW1010-4 inputs an optical signal having _a wavelength λ1 output from the port 11-2-q3 of the optical SW1010-1 and outputs the optical signal from the port 11-2-1.

When the ONU # 12 transmits an upstream optical signal having a wavelength λ ₂ addressed to the ONU # 31, the optical SW1010-1 outputs the optical signal input from the port 11-1-2 from the port 11-2-q2. Port 11-1-p1 of the optical SW1010-3 inputs an optical signal output from the port 11-2-q2 of the optical SW1010-1. The optical SW1010-3 performs the same return communication as the optical SW10b shown in FIG. 3 with respect to the optical signal having the wavelength λ ₂ input from the port 11-1-p1, and outputs the optical signal from the port 11-1-1.

Note that FIG. 27 shows only the upstream optical signal. In the case of vertical and bidirectional communication, a WDM filter (separation unit) for separating and transmitting an upstream optical signal and a downstream optical signal is provided on the transmission lines 50-1, 50-2, and 50-3. Then, the downlink optical signal is connected in the opposite direction to the uplink optical signal described above.

FIG. 28 is a diagram showing another example of optical SW scalability in a cascade configuration. The configuration shown in FIG. 28 differs from the configuration shown in FIG. 27 in that the optical SW1010-n (n is an integer of 1 or more and N or less) has some other optical SW1010- (n is an integer of 1 or more and N or less) due to some ports 11-2. It is a point connected to port 11-1 of n + 1). It is assumed that the optical SW1010- (N + 1) is the optical SW1010-1. As a result, a plurality of optical SW1010s are connected in series.

In FIG. 28, ports 11-1-1, 11-1-2, 11-1-3, ... Of the optical SW1010-n (n is an integer of 1 or more and N or less) are ONU # n1, ONU # n2, ONU. Connected to # n3, ..., Ports 11-2-1, 11-2-2, 11-2-3, ... are transmission lines 50 of uplink # n1, uplink # n2, uplink # n3, ... Connected to -2. Further, the port 11-2-q1 of the optical SW1010-n is the port 11-1-p1 of the optical SW1010- (n + 1), and the port 11-2-q2 of the optical SW1010-n is the port 11 of the optical SW1010- (n + 1). At -1-p2, the port 11-2-q3 of the optical SW1010-n is connected to the port 11-1-p3 of the optical SW1010- (n + 1).

For example, when ONU # 11 transmits an upstream optical signal having a wavelength λ ₁ addressed to uplink # 41, the optical SW1010-1 transmits an optical signal input from port 11-1-1 from port 11-2-q1. Output. Port 11-1-p1 of the optical SW1010-2 inputs an optical signal output from the port 11-2-q1 of the optical SW1010-1 and outputs the optical signal from the port 11-2- _q1 according to the wavelength λ1. Port 11-1-p1 of the optical SW1010-3 inputs an optical signal output from the port 11-2-q1 of the optical SW1010-2, and outputs the optical signal from the port 11-2- _q1 according to the wavelength λ1. Port 11-1-p1 of the optical SW1010-4 inputs an optical signal output from the port 11-2-q1 of the optical _SW1010-3 , and outputs the optical signal from the port 11-2-1 according to the wavelength λ1.

When the ONU # 12 transmits an upstream optical signal having a wavelength λ ₂ addressed to the ONU # 31, the optical SW1010-1 outputs the optical signal input from the port 11-1-2 from the port 11-2-q2. Port 11-1-p2 of the optical SW1010-2 inputs an optical signal output from the port 11-2-q2 of the optical SW1010-1. The optical SW1010-2 outputs an optical signal input from the port 11-1-p2 from the port 11-2 _- q2 according to the wavelength λ2. Port 11-1-p2 of the optical SW1010-3 inputs an optical signal output from the port 11-2-q2 of the optical SW1010-2. The optical SW1010-3 performs the same return communication as the optical SW10b shown in FIG. 3 with respect to the optical signal input from the port 11-1 _- p2 according to the wavelength λ2, and outputs the optical signal from the port 11-1-1. ..

Note that FIG. 28 shows only the upstream optical signal. In the case of vertical and bidirectional communication, WDM filters are provided on the transmission lines 50-1, 50-2, and 50-3 to separate and transmit the upstream optical signal and the downstream optical signal. Then, the downlink optical signal is connected in the opposite direction to the upstream optical signal described above.

Subsequently, the configuration of the optical transceiver will be described with reference to FIGS. 29 to 32. Although it will be described as a part of the configuration example of the subscriber device 40 connected to the optical SW, it may be used in a control unit, a monitoring unit, or the like, and it will be described as a transmission / reception set. May be only. 29 and 30 are block diagrams of the two-core type subscriber device 401. In addition, in FIGS. 29 to 32, since a plurality of configurations are described, the same configurations may be designated by the same reference numerals and the description thereof may be omitted.
The subscriber device 401 shown in FIG. 29 (A) has an optical transceiver 411. The optical transceiver 411 includes a tunable light source 451 and a tunable wavelength receiver 452. The tunable light source 451 is an example of an optical transmission unit, and the tunable wavelength receiver 452 is an example of an optical reception unit.

The tunable light source 451 outputs light of a set wavelength. The wavelength set in the tunable light source 451 is variable. The tunable light source 451 has, for example, a tunable laser diode (LD). The wavelength variable light source 451 is, for example, a combination of a gain medium and a resonator having a variable resonator length, for example, a combination of a gain medium and a wavelength selection medium, for example, a gain medium and a resonator having a variable resonator length, and a wavelength selection medium. Have any of the combinations of. For example, the wavelength variable light source 451 has a duplexer or a power splitter and an optical transmitter (Tx) for each wavelength, and transmits an optical signal from an optical transmitter having a set wavelength. The duplexer is, for example, an AWG. The duplexer or power splitter combines the input light and outputs an optical signal of that wavelength. For example, a duplexer or power splitter has a multi-wavelength or broadband light source and a tunable wavelength filter (tf) that selects and outputs a set wavelength. The variable wavelength filter passes through an optical signal having a set wavelength (variable) in the input optical signal. 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 also 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). As the external modulator, MZ (Mach-Zender), EA (Electro-Absorption), SOA (Semiconductor Optical Amplifier), etc. can be used, and the structure can be integrated with the light source. The signal and the control signal can be modulated, or the main signal and the control signal can be modulated separately by different modulators.

The variable wavelength receiver 452 has a variable wavelength filter and an optical receiver. The tunable wavelength filter passes light of a set wavelength (variable) in the input optical signal. The optical receiver receives an optical signal that has passed through a tunable wavelength filter. The selection of a tunable wavelength filter, that is, a signal having a predetermined wavelength, may be performed after receiving the light. For example, a beat signal centered on a frequency corresponding to a wavelength difference from a station emission having a predetermined wavelength may be selected with a frequency width corresponding to the band of the signal. Depending on the configuration of the optical SW, the multiplexing method, and the like, a configuration using a transmitter having a non-variable wavelength or a configuration not using a variable wavelength filter or a demultiplexer may be used.

The subscriber device 401a shown in FIG. 29B has an optical transceiver 411a. The optical transceiver 411a includes a tunable light source 451, a tunable filter 453, and an optical receiver 454. The tunable light source 451 is an example of an optical transmitter, and the tunable filter 453 and the optical receiver 454 are an example of an optical receiver. The wavelength variable filter 453 inputs an optical signal from a transmission line and passes light of a set wavelength through an optical receiver 454. The wavelength set in the tunable filter 453 is variable. The optical receiver 454 receives the optical signal passed by the tunable filter 453. The subscriber device 40 on the receiving side may be configured not to use the tunable filter 453 depending on the configuration of the optical SW, the multiplexing method, and the like.

The subscriber device 401b shown in FIG. 29 (C) has an optical transceiver 411b. The optical transceiver 411b includes a light source 455, a tunable filter 456, and a tunable wavelength receiver 452. The light source 455 and the tunable wavelength filter 456 are examples of an optical transmitting unit, and the variable wavelength receiver 452 is an example of an optical receiving unit. The light source 455 outputs light of a single wavelength (eg, wavelength λ ₁ ). That is, the light source 455 is not tunable. The wavelength variable filter 456 inputs the optical signal output from the light source 455 and outputs the optical signal of the set wavelength to the transmission line. The wavelength set in the tunable filter 456 is the wavelength of the optical signal output by the light source 455.

The subscriber device 401c shown in FIG. 30 (A) has an optical transceiver 411c. The optical transceiver 411c includes a tunable light source 451, a plurality of optical receivers 454-1 to 454-3, and a demultiplexer 457. The tunable light source 451 is an example of an optical transmitter, and the optical receivers 454-1 to 454-3 and the demultiplexer 457 are examples of an optical receiver. Although FIG. 30A shows the case where there are three optical receivers 454-1 to 454-3, the number of optical receivers 454-1 to 454-3 is not limited. Also in the following description, the number of optical receivers 454-1 to 454-3 is not particularly limited. The demultiplexer 457 demultiplexes the optical signal input from the transmission line according to the wavelength. The optical signal demultiplexed by the demultiplexer 457 is input to the optical receivers 454-1 to 454-3. The optical receivers 454-1 to 454-3 receive the optical signal demultiplexed by the demultiplexer 457.

The subscriber device 401d shown in FIG. 30B has an optical transceiver 411d. The optical transceiver 411d includes a plurality of light sources 455-1 to 455-3, a combiner 458, and a tunable wavelength receiver 452. The light sources 455-1 to 455-3 and the combiner 458 are examples of an optical transmitter, and the variable wavelength receiver 452 is an example of an optical receiver. Although FIG. 30B shows a case where the number of light sources 455-1 to 455-3 is three, the number of light sources 455-1 to 455-3 is not limited. Also in the following description, the number of light sources 455 is not particularly limited. The light sources 455-1 to 455-3 transmit optical signals having different wavelengths. The combiner 458 combines a plurality of optical signals output from each of the light sources 455-1 to 455-3 and outputs them to the transmission line.

The subscriber device 401e shown in FIG. 30C has an optical transceiver 411e. The optical transceiver 411e includes a plurality of light sources 455-1 to 455-3, a combiner 458, a plurality of optical receivers 454-1 to 454-3, and a demultiplexer 457. The light sources 455-1 to 455-3 and the combiner 458 are examples of the optical transmitter, and the optical receivers 454-1 to 454-3 and the demultiplexer 457 are examples of the optical receiver. In the subscriber device 401e, the optical signals output from the light sources 455-1 to 455-3 are combined by the combiner 458 and output to the transmission line. In the subscriber device 401e, the optical signal input from the transmission line is demultiplexed by the wavelength in the demultiplexer 457, and the demultiplexed optical signal is received by the optical receivers 454-1 to 454-3.
It is desirable to combine a plurality of combine / demultiplexers or combiners if the combined demultiplexing wavelengths are the same. That is, the demultiplexer 457 and the combiner 458 may be combined.

31 and 32 are block diagrams of a single-core subscriber device 402. The subscriber device 402 shown in FIG. 31 (A) has an optical transceiver 412. The optical transceiver 412 includes a tunable light source 451, a tunable wavelength receiver 452, and a WDM filter 459. The optical transceiver 412 shown in FIG. 31 (A) differs from the optical transceiver 411 shown in FIG. 29 (A) in that it further includes a WDM filter 459. The WDM filter 459 separates the uplink signal and the downlink signal according to the wavelength. The WDM filter 459 outputs the optical signal generated by the wavelength variable light source 451 to the transmission line, and outputs the optical signal input from the transmission line to the variable wavelength receiver 452. Similar to the subscriber device 401, the subscriber device 402 further has an external modulator, and can output a main signal (or a signal obtained by superimposing a control signal on the main signal) by using the external modulator.

Here, the WDM filter 459 shown in FIGS. 31 and 32 may be a power splitter. The WDM filter 459 is suitable when the insertion loss is sufficiently low with respect to the power splitter and the wavelengths used on the transmitting side and the receiving side do not overlap. It is suitable when the wavelengths used on the transmitting side and the receiving side overlap, for example, in the case of return communication between subscribers of the same type.
In FIGS. 31 and 32, the WDM filter 459 is built into the optical transceiver 412, but may be outside the optical transceiver 412 or outside the subscriber device 40.

The subscriber device 402a shown in FIG. 31 (B) has an optical transceiver 412a. The optical transceiver 412a includes a tunable light source 451, a tunable filter 453, an optical receiver 454, and a WDM filter 459a. The optical transceiver 412a shown in FIG. 31B differs from the optical transceiver 411a shown in FIG. 29B in that it further includes a WDM filter 459a. The WDM filter 459a separates the uplink signal and the downlink signal according to the wavelength. The WDM filter 459a outputs the optical signal generated by the wavelength-variable light source 451 to the transmission line, and outputs the optical signal input from the transmission line to the wavelength-variable filter 453. The subscriber device 402 on the receiving side may be configured not to use the tunable filter 453 depending on the configuration of the optical SW, the multiplexing method, and the like.

The subscriber device 402b shown in FIG. 31 (C) has an optical transceiver 412b. The optical transceiver 412b includes a light source 455, a tunable wavelength filter 456, a tunable wavelength receiver 452, and a WDM filter 459b. The optical transceiver 412b shown in FIG. 31C differs from the optical transceiver 411b shown in FIG. 29C in that it further includes a WDM filter 459b. The WDM filter 459b separates the uplink signal and the downlink signal according to the wavelength. The WDM filter 459b outputs an optical signal that has passed through the wavelength variable filter 456 to a transmission line, and outputs an optical signal input from the transmission line to a variable wavelength receiver 452.

The subscriber device 402c shown in FIG. 32 (A) has an optical transceiver 412c. The optical transceiver 412c includes a tunable light source 451, a plurality of optical receivers 454-1 to 454-3, a demultiplexer 457, and a WDM filter 459c. The optical transceiver 412c shown in FIG. 32 (A) differs from the optical transceiver 411c shown in FIG. 30 (A) in that it further includes a WDM filter 459c. The WDM filter 459c separates the uplink signal and the downlink signal according to the wavelength. The WDM filter 459c outputs the optical signal generated by the wavelength-variable light source 451 to the transmission line, and outputs the optical signal input from the transmission line to the duplexer 457.

The subscriber device 402d shown in FIG. 32 (B) has an optical transceiver 412d. The optical transceiver 412d includes a plurality of light sources 455-1 to 455-3, a combiner 458, a tunable wavelength receiver 452, and a WDM filter 459d. The optical transceiver 412d shown in FIG. 32 (B) differs from the optical transceiver 411d shown in FIG. 30 (B) in that it further includes a WDM filter 459d. The WDM filter 459d separates the uplink signal and the downlink signal according to the wavelength. The WDM filter 459d outputs the optical signal combined with the combiner 458 to the transmission line, and outputs the optical signal input from the transmission line to the variable wavelength receiver 452.

The subscriber device 402e shown in FIG. 32 (C) has an optical transceiver 412e. The optical transceiver 412e includes a plurality of light sources 455-1 to 455-3, a combiner 458, a plurality of optical receivers 454-1 to 454-3, a demultiplexer 457, and a WDM filter 459e. The optical transceiver 412e shown in FIG. 32 (C) differs from the optical transceiver 411e shown in FIG. 30 (C) in that it further includes a WDM filter 459e. The WDM filter 459e separates the uplink signal and the downlink signal according to the wavelength. The WDM filter 459e outputs the optical signal combined with the combiner 458 to the transmission line, and outputs the optical signal input from the transmission line to the duplexer 457.
It is desirable to combine multiple combine / demultiplexers or combiners if the combined wavelengths of the combined demultiplexers are the same. That is, the demultiplexer 457 and the combiner 458, the demultiplexer 458 and the WDM filter 459e, the demultiplexer 457 and the WDM filter 459e, and the demultiplexer 457 and the combiner 458 and the WDM filter 459e may be combined.

The above is the configuration of the one-core type subscriber device 401 and the two-core type subscriber device 402. In the present invention, any of the configurations shown in FIGS. 29 to 32 may be used as the subscriber device 40.

Subsequently, a configuration example of the monitoring unit 60 and the monitoring unit 65 will be described. First, in the above, the signal is branched and monitored using a power splitter, but without branching, gain, applied voltage, and current due to signal conduction at a frequency of at least about the carrier wave of AMCC in the transmission line. It may be configured by incorporating a medium whose resistance changes, for example, a semiconductor amplifier or the like. Wavelength-multiplexed signals do not branch by using a medium that is highly wavelength-dependent for changes in gain, voltage, current, resistance, etc. using superlattice structures such as MQW (Multiple quantum well) and photonic crystal. You may monitor it.
In the following, a configuration example of the monitoring unit 60 and the monitoring unit 65 will be described with reference to FIGS. 33 to 37 in the case of branching. In FIGS. 33 to 37, the monitoring unit 60 will be described as an example. In FIGS. 33 to 37, an example of monitoring in the up direction and the down direction will be described, but the monitoring unit 60 outputs from the subscriber device 40, for example, from the viewpoint of monitoring the subscriber device 40. Monitoring may be performed in only one direction. In the case of only one direction, if the transmitter and the receiver are replaced with a combination of a transmitter and a receiver connected to, for example, a transmitter / receiver, a power splitter, or a duplexer, the two directions are obtained.

Further, although the receiver and the transmitter are described in close proximity to the power splitter 61 and the duplexer branching from the transmission line, they may be arranged in a distant place, for example, via one or a plurality of optical SWs. Often, the receiver or transmitter of the control unit may also serve as the receiver or transmitter of the monitoring unit 60 and may be connected to them.
The monitoring unit 60 monitors the optical signal. For monitoring, place the optical receiver or optical transmitter / receiver in the vicinity of the turnout or duplexer, or in a place where optical signals can be connected. The monitoring unit 60 branches the optical signal by the junction or demultiplexer, monitors the received optical signal, and further receives the control signal superimposed on the received optical signal.

The monitoring unit 60 includes a switch or a demultiplexer provided at a port or transmission line on the input side, via or output side of the optical SW, or a connection point thereof, and a cutoff unit that cuts off the main signal in some cases. Have. For example, a duplexer is arranged at port 11-2 or transmission line 2 on the ground side or its connection point, and the input optical signal is transmitted from the optical SW to the upstream optical signal from the optical SW and from another ground or higher network according to the wavelength. The input downlink signal may be separated and output to the optical SW. When setting or changing the arrangement of the blocking part in the case of providing the blocking part, for example, when setting or changing in both directions, it is preferable to set or change the part in the combined wave or the merged state, and individually, for example, separately set or change the upper and lower parts. In this case, a demultiplexed or branched portion is preferable.

The monitoring unit 60 may be connected via an optical SW different from the optical SW to which the subscriber device 40 to be controlled is connected. For example, the optical signal separated from the transmission path in which the junction branching device transmits the optical signal of the subscriber device 40 to be controlled is input to the optical SW connected to the monitoring unit 60 separately from the connection to the subscriber device 40. It is multiplexed as necessary, transmitted to the optical SW to which the monitoring unit 60 is connected, and connected to the monitoring unit 60. Alternatively, it is not input to the optical SW, but is directly input to the optical SW connected to the control unit or the monitoring unit 60.

The junction branch or duplexer divides the ports constituting the optical SW into a plurality of groups, and is assigned to port 11-2 or the transmission line 2 or port 2 connected to the port 11-2 or the port 2 belonging to one group when not connected within the group. It may be provided in the connected transmission line 2. The branching may be performed before the wavelength separation or after the separation. It may be provided on the optical SW side or on the transmission line side of the duplexer for upper / lower multiplexing. If it is provided on the transmission line side, the uplink and downlink optical signals transmitted on the transmission line can be branched by one unit. In that case, the branched up light signal and down light signal are input to the ports of the optical SW, respectively. The optical SW outputs the input optical signal from the port connected to the monitoring unit 60. As a result, the monitoring unit 60 receives the branched optical signal.

The monitoring unit 60a shown in FIG. 33A shows a specific configuration of the monitoring unit 60. The monitoring unit 60a has a power splitter 61 and a plurality of receivers 62-1 to 62-2. The receivers 62-1 to 62-2 receive the optical signal branched by the power splitter 61. The receivers 62-1 to 62-2 may be provided in a number corresponding to the number of branches of the power splitter 61. In FIG. 33 (A), a 2 × 2 power splitter 61 is used, and the number of branches branched in each direction or other than the main signal path on the input side and the output side (2) -the main signal path (1) = 1. An example is shown in which a total of one is provided. If it is a 3 × 3 power splitter 61, it can be provided with two each. From the viewpoint of reducing the influence of reflection or the like, a power splitter 61 such as 1 × 2 or 1 × 3 that does not have a port for not being monitored may be used. In this case, the receiver 62-1 or 62-2 has the number of branches (2) -main signal path (1) = 1 and the number of branches (1) -main signal path (1) = 0, the number of branches (3)-. The main signal path (1) = 2 and the number of branches (1) -the main signal path (1) may be 0.
Even if the paths other than the main signal branched by the power splitter 61 are branched as in the WDM device 63b of FIG. 33 (B) and each is received, a plurality of power splitters 61 are installed in the main signal path, respectively. It may be branched and received.

The monitoring unit 60a shown in FIG. 33A shows a specific configuration of the monitoring unit 60. The monitoring unit 60a has a power splitter 61 and a plurality of receivers 62-1 to 62-2. The receivers 62-1 to 62-2 receive the optical signal branched by the power splitter 61. The number of receivers 62 is not particularly limited.

The monitoring unit 60b shown in FIG. 33B shows a specific configuration of the monitoring unit 65. The monitoring unit 60b includes a power splitter 61, a plurality of receivers 62-1 to 62-6, and a plurality of WDM devices 63b-1 to 63b-2. Receivers 62-1 to 62-3 are connected to the WDM device 63b-1. Receivers 62-4 to 62-6 are connected to the WDM device 63b-2. The WDM device 63b-1 splits the optical signal branched by the power splitter 61 and outputs it to the receivers 62-1 to 62-3. The WDM device 63b-2 splits the optical signal branched by the power splitter 61 and outputs it to the receivers 62-4 to 62-6. The number of WDM devices 63b is not particularly limited.

The monitoring unit 60c shown in FIG. 33C has a power splitter 61, a plurality of receivers 62-1 to 62-2, and a WDM device 63c. The WDM device 63c combines a plurality of input optical signals and outputs them to the transmission line 601. The WDM device 63c demultiplexes the optical signal input from the transmission line 601 and outputs it to the transmission lines 602-1 and 602-2.

The monitoring unit 60d shown in FIG. 34 (A) has a plurality of power splitters 61-1 to 61-3, a plurality of receivers 62-1 to 62-6, and a WDM device 63d. The transmission line 602-1 is provided with a power splitter 61-1, the transmission line 602-2 is provided with a power splitter 61-2, and the transmission line 602-3 is provided with a power splitter 61-3. Receivers 62-1 to 62-2 are connected to the power splitter 61-1, receivers 62-3 to 62-4 are connected to the power splitter 61-2, and receiver 62 is connected to the power splitter 61-3. -5 to 62-6 are connected. The WDM device 63d demultiplexes the optical signal input from the transmission line 601 and outputs the optical signal to the transmission lines 602-1 to 602-3. The WDM device 63d combines the optical signals input from the transmission lines 602-1 to 602-3 and outputs them to the transmission line 601.
In FIG. 34 (A), each transmission line 602-1 to 602-after demultiplexing by the WDM device 63d when viewed from the transmission line 601 or before combining by the WDM device 63d when viewed from the transmission line 602. Although it is assumed that the receivers 62-1 to 62-6 are provided in 3, the receiver 62 may not be provided in the transmission line that does not require reception.

The monitoring unit 60e shown in FIG. 34B includes a plurality of power splitters 61-1 to 61-2, a plurality of receivers 62-1 to 62-2, and a plurality of WDM devices 63e-1 to 63e-2. Have. Transmission lines 602-1 and 602-2 are provided between the WDM device 63e-1 and the WDM device 63e-2. A power splitter 61-1 is provided on the transmission line 602-1, and a power splitter 61-2 is provided on the transmission line 602-2. A receiver 62-1 is connected to the power splitter 61-1 and a receiver 62-2 is connected to the power splitter 61-2. The WDM device 63e-1 demultiplexes the optical signal input from the transmission line 601 and outputs the optical signal to the transmission lines 602-1 to 602-2. The WDM device 63e-1 combines the optical signals input from the transmission lines 602-1 to 602-2 and outputs them to the transmission line 601. The WDM device 63e-2 demultiplexes the optical signal input from the transmission line 603 and outputs it to the transmission lines 602-1 to 602-2. The WDM device 63e-2 combines the optical signals input from the transmission lines 602-1 to 602-2 and outputs them to the transmission line 603.
In FIG. 34 (B), receivers 62-1 to 62-2 are provided in the transmission lines 602-1 to 602-2 after demultiplexing and before combining, but the transmission lines do not require reception. Does not have to include the receiver 62.

The subscriber device 40 may be controlled from the monitoring unit. When exchanging the control signal with the subscriber device 40, the monitoring unit may set or change the wavelength of the subscriber device 40 in the same manner as the control unit 20. However, when changing the setting, especially the wavelength, optical signals other than the wavelength set at the time of change do not reach the unintended destination, so it is desirable to set so that the output from the target device does not reach the destination until the change is completed. ..
The configuration controlled from the monitoring unit will be described with reference to FIG. 35.

The monitoring unit 60f shown in FIG. 35 (A) has a power splitter 61, a plurality of receivers 62-1 to 62-2, and a modulator 64. The transmission line 601 is provided with a power splitter 61 and a modulator 64. As described above, the monitoring unit 60f includes a modulator in the middle of the path of the main signal, and the modulator 64 modulates the main signal. Modulators include external modulators, amplifiers that modulate the amplification factor according to the control signal, gain saturation according to the optical signal from the monitoring unit 60f, intermodulation, and non-linear effects such as four-light wave mixing and the Raman effect. It may be modulated.
If the extinction ratio of the modulator is high enough not to affect other optical signals, the modulator may also serve as a blocking unit.
FIG. 35A shows a configuration in which the monitoring unit 60f includes a power splitter 61, receivers 62-1 to 62-2, and a modulator 64, but the modulator 64 is about the carrier wave of AMCC. It can be replaced by a device that can modulate the input intensity monitor and output by frequency, such as a multi-electrode optical semiconductor amplifier.

When modulating with external light, the power splitter 61 also serves as a modulator without separately providing a modulator 64. The power splitter 61 is a semiconductor optical amplifier with a large gain saturation and a non-linear effect, a non-linear fiber (Highly Nonlinear Fiber: HNLF), a non-linear optical crystal, and a periodic polarization inversion optical element (for example, PPKTP) that facilitates pseudo-phase matching for non-linear mutual. (Periodically Polarized Potassium Titanyl Phosphate), PPPLN (Periodically Polarized Lithium Niobate), PPLT (Periodically Polarized Lithium Tantalate), etc. Let external light act.

When remodulating a signal that has already been modulated by AMCC, the effect of the already modulated is expected. In such a case, it is desirable that the frequency band of the control signal be different from the frequency band that has already been modulated. The difference in frequency band is, for example, 2B or more when the modulation band of the signal is B so that the modulation side bands of the existing modulation and the new modulation do not overlap each other, or more from the viewpoint of preventing interference, or vice versa. Assuming that it is cut out with a filter, it may be about 0.5 to 0.8 times that. Further, after the inverse modulation shown in FIG. 35 (B), another modulator 64 may be used for modulation. In this case, since the influence of the already-modulated is reduced, the frequency bands may be overlapped. Further, it may be modulated by a signal corresponding to the product of the reverse modulation of the existing modulation and the new modulation, and the modulation by the plurality of modulators 64 may be combined with the modulation of one modulator 64.
The monitoring unit 60f may perform the process described with reference to FIG. 35 (B) in order to reduce the influence of the AMCC on the main signal.

As shown in FIG. 35 (B), the monitoring unit 60f has the same modulation method as the AMCC received by the receiver 62-2 and the reverse signal (in the case of 1/0 intensity modulation, 0 overlaps with the signal modulated by 1). , 1 may be superimposed on the signal modulated by 0, and the main signal modulated by AMCC may be modulated by the modulation having the opposite phase and the intensity that just cancels out. Thereby, the influence on the main signal of AMCC can be reduced.

The monitoring unit 60g shown in FIG. 36 includes a plurality of power splitters 61-1 to 61-2, a plurality of receivers 62-1 to 62-2, a plurality of WDM devices 63g-1 to 63g-2, and a plurality of receivers. It has modulators 64g-1 to 64g-2. Transmission lines 602-1 and 602-2 are provided between the WDM device 63g-1 and the WDM device 63g-2. The transmission line 602-1 is provided with a modulator 64g-1 and a power splitter 61-1, and the transmission line 602-2 is provided with a 64g-2 and a power splitter 61-2. A receiver 62-1 is connected to the power splitter 61-1 and a receiver 62-2 is connected to the power splitter 61-2. The WDM device 63g-1 demultiplexes the optical signal input from the transmission line 601 and outputs the optical signal to the transmission lines 602-1 to 602-2. The WDM device 63g-1 combines the optical signals input from the transmission lines 602-1 to 602-2 and outputs them to the transmission line 601. The WDM device 63e-2 demultiplexes the optical signal input from the transmission line 603 and outputs it to the transmission lines 602-1 to 602-2. The WDM device 63e-2 combines the optical signals input from the transmission lines 602-1 to 602-2 and outputs them to the transmission line 603. The optical signals input from the transmission lines 602-1 to 602-2 to the WDM device 63e-1 and the WDM device 63e-2 are modulated by the modulators 64g-1 and 64g-2.
In FIG. 36, the branched optical signal is modulated after being received by the receivers 62-1 to 62-2, but the quality of the received optical signal due to the modulation, for example, the signal-to-noise ratio of the received control signal or SN (signal-to). When it is not necessary to consider the deterioration of -noise ratio), the modulated optical signal may be branched by the power splitters 61-1 to 61-2 and received by the receivers 62-1 to 62-2. ..

The configuration in which the monitoring unit uses the transmitter will be explained. Like the subscriber device 40 and the control unit 20, the monitoring unit includes an optical transmitter / receiver, an optical transceiver having a variable wavelength or a non-variable wavelength, and is connected to the port of the optical SW. If the transmitter is a variable wavelength transmitter, an optical signal of any wavelength can be transmitted. The monitoring unit transmits a control signal to the subscriber device 40 as an optical signal. The power splitter of the transmission line that transmits the optical signal of the subscriber device 40 to be controlled merges the control signal with the optical signal transmitted through the transmission line. With this configuration, the monitoring unit receives a request for changing the connection destination from the subscriber device 40, etc., and transmits a control signal to the subscriber device 40 even when the subscriber device 40 is performing normal communication. It becomes possible to carry out switching and the like. The specific configuration in which the monitoring unit includes the transmitter will be described later.

When the subscriber device 40 is performing normal communication, it cannot communicate with the control unit 20 when the control unit 20 controls the subscriber device 40 with an optical signal directly or via an optical SW or the like. When the monitoring unit is provided with a transmitter, it is possible to instruct various settings of the subscriber device 40 and the like. That is, the monitoring unit inputs the optical signal inserted and separated into the transmission path for transmitting the optical signal to the subscriber device 40 to be controlled by the power splitter.

An example will be described using AMCC. Usually, the AMCC modulates the main signal and the AMCC signal with a signal superimposed by an electric stage, or further modulates the main signal with an optical stage. On the other hand, the transmitter of the monitoring unit inputs an optical signal corresponding to the control signal separately from the main signal and multiplexes it. The wavelength of the optical signal corresponding to the control signal is a wavelength that passes through the same path as the main signal from the transmitter to the point where the control signal corresponding to AMCC is received at least. The monitoring unit does not modulate the main signal, but separately modulates the input optical signal intensity with the frequency of the AMCC carrier wave, so that the optical signal that combines the main signal and the control signal equivalent to the AMCC is the carrier wave of the AMCC. It is equivalent to modulation with frequency.
Here, the example in which the intensity modulation of the control signal is received together with the main signal is shown, but in the case of phase modulation or the like, the control signal may be received by using delayed detection or local emission.

Here, if the wavelength difference between the main signal and the control signal equivalent to AMCC is such that beat noise can be ignored, for example, the total line width of both lights, and if the line width is the same, the AMCC is more than double the line width. It can be demodulated in the same way as the average value of the light intensities of both in 1 bit or 1 baud time as if it was modulated by AMCC. When the modulation sideband at the frequency of the carrier wave in AMCC and the modulation sideband at the bit rate or baud rate of the main signal are superimposed, it is difficult to demodulate by direct detection with the same modulation as usual. However, for example, coherent reception or the like may be performed, and the light may be removed by the electric stage by the most probable determination or the like and received. It may be synchronized with the phase. In the case of phase synchronization, it is possible even if the AMCC is modulated using the phase. In this case, the phase after multiplexing is modulated so as to be the phase after modulation.

The intensity and wavelength of the signal light and the control light may be measured by different measuring means, for example, and a part of the optical signal of the main signal and the optical signal input to the power splitter from the transmitter of the monitoring unit is the monitoring unit. It may be measured by the same measuring means so that it can be received by the receiver of. The latter has the effect of having few measuring means. For example, after multiplexing, the effect of beat noise between lights on the main signal may be observed and adjusted. For example, the main signal is measured before multiplexing the control lights, and then the signal after multiplexing the control lights is equivalent to applying the desired AMCC, or after multiplexing the main signal due to beat noise between the lights. Measure the effect on the light. Then, the intensity and wavelength of the optical signal of the control signal are adjusted. In the case of phase synchronization, feedback may be given in the measurement after multiplexing.

Next, an example of another configuration in which the transmitter is used in the monitoring unit will be described with reference to FIG. 37. As shown in FIG. 37, even if the control unit 20 is looped using the folded transmission line (upper middle of the figure) instead of being installed at the port of the optical SW10, the transmission line or their connection point, the electricity described later Similar to the processing unit, the optical SW10 may be used as a sash (lower middle of the figure).

For example, the monitoring unit 60h terminates the main signal, and the transmitter superimposes AMCC on the photoelectrically converted main signal and modulates it, or transmits an optical signal modulated by the main signal and further modulated by AMCC. Unlike the monitoring unit 60h described above, the monitoring unit 60h does not have a power splitter for joining and branching the main signal, but similarly, the port, transmission line or theirs on the input side or via or output side of the optical SW. It may be installed at the connection point. In this configuration, since the signal is terminated once, the wavelength up to the monitoring unit 60h and the wavelength from the monitoring unit may be different as long as they are transmitted along the desired path.

The monitoring unit 60h does not have an optical receiver or an optical transmitter / receiver, and the branched optical signal may be transmitted and output to the control unit 20 via, for example, the optical SW10. When outputting to the control unit 20, the control unit 20 includes an optical receiver and an optical transmitter / receiver, and the monitoring unit 60h is provided at the input side or via or output side port or transmission line of the optical SW or its connection point. It is a function to set the path to the power splitter or the duplexer and the control unit 20, and the power splitter or the duplexer or the path as needed. The path may be realized by the optical SW, and the setting may be performed by the control unit.
The monitoring unit 60h may include an optical receiver and an optical transmitter / receiver, and may further include a blocking unit. At the time of initial setting, setting change, and abnormality detection, the route from the monitoring unit to the output destination may be blocked or blocked by the blocking unit to set, change, or block the subscriber device.

As described above, the monitoring unit 60-60h monitors the optical signal. The monitoring units 60 to 60h monitor by an optical signal branched by a power splitter or a WDM device, and further receive a control signal superimposed on the received optical signal. Although FIGS. 33 to 37 show a configuration in which the monitoring units 60 to 60h include the receiver 62, the monitoring units 60 to 60h may include the transmitter.

The monitoring units 60 to 60h may be connected via an optical SW different from the optical SW to which the subscriber device 40 to be controlled is connected. In this case, the optical signal separated by the power splitter 61 in the transmission line for transmitting the optical signal of the subscriber device 40 to be controlled is an optical SW different from the optical SW connected to the subscriber device 40, and is a monitoring unit. It is input to the optical SW to which 60 to 60h is connected. At this time, it is multiplexed as necessary, transmitted to the optical SW to which the monitoring units 60 to 60h are connected, and connected to the monitoring units 60 to 60h.
In the following description, when the monitoring units 60 to 60h are not particularly distinguished, they will be described as the monitoring unit 60.

Hereinafter, an example of an optical access system using an optical SW having the above-mentioned functions will be described.

(Configuration example of optical access system 100)
FIG. 38 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) 300. The OPS 300 may be integrated with the control unit 20, and may be referred to as a control unit or OPS on behalf of both. 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 the 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, bus type, mesh type, ring type, and multi-ring 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 the transmission line 511 and the 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 that transmit 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, and the connection between the grounds is connected so as to be a full mesh. ing. In this configuration, 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. An example will be described when the device is connected to an optical communication device. 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 subscriber devices 40 of M units (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 unit 230, a duplexer 241 and a duplexer 242, a branching unit 250, and a monitoring unit 260. The monitoring unit 260 may be replaced with any of the above-mentioned monitoring units 60 to 60h.

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 / lower multiplex separation that separates an uplink signal and a downlink signal according to the 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. The wavelength combiner / demultiplexer 220 inputs the downlink optical signal output by the optical SW 210 from the transmission line 522 and outputs the downlink optical signal to the subscriber device 40 via the transmission line 501.

The control unit 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 unit 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 unit 230 by the transmission line 533. The control unit 230 includes a wavelength demultiplexer 231, an optical receiver (Rx) 232 for each wavelength channel, and a tunable transmitter 233. The wavelength duplexer 231 is, for example, an AWG. The wavelength demultiplexer 231 demultiplexes the light input to the port on the receiving side 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 produces light of a variable wavelength. The tunable transmitter 233 transmits an optical signal having a variable wavelength by using the light generated by the tunable laser diode. 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 SW 210 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 SW 210 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 SW 210 via the transmission line 552.

The monitoring unit 260 has a wavelength demultiplexer 261 and an optical receiver (Rx) 262 for each wavelength. The wavelength duplexer 261 is connected to the optical SW210 via a transmission line 560. The optical SW 210 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 duplexer 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 unit 260 monitors the state of communication transmitted / received by the subscriber device 40 by the optical signal received by the optical receiver 262. The monitoring unit 260 may output the monitoring result to the control unit 230 or the control unit 301 included in the OPS 300. Here, the control unit 230 and the control unit 301 are used, but they may be the same. The monitoring unit 260 may output the monitoring result to the control unit 230, and the control unit 230 may output the output to the control unit 301. The control unit 230 and the control unit 301 may be the same. In that case, it is not necessary to output the output from the control unit 230 to the control unit 301 to the outside of the control unit.

The OPS 300 has a control unit 301 and a management DB 350. The control unit 301 is connected to the optical GW 200. The control unit 301 has 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. The control unit 301 may be installed for each optical SW 210, or may be installed for each of a plurality of optical SWs. As described above, the wavelength control unit 310 executes the same processing as the wavelength control unit 25 in FIG.

The control unit 301 is connected to the management database (DB) 350. The control unit 301 mutually exchanges information regarding the user and the wavelength used with the management DB 350. The management DB 350 stores the wavelength used by each user and the destination information. 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. 39 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 unit 230, the branch unit 250, the monitoring unit 260, the ground, and the like at the source or destination of the optical signal. Is.

The wavelength table includes a user wavelength table and an inter-station wavelength table.
FIG. 40 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. The management DB 350 may manage the wavelength table for each transmission line connected to the optical SW210.

FIG. 41 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 inside.

Here, the operation when the subscriber device 40 is newly connected will be described. FIG. 42 is a flowchart showing an initial setting process of the optical access system 100 when a new subscriber device is connected. 38 and 42 will be used to describe the operation of the optical access system 100 when the subscriber device 40-1 is newly connected to the optical GW 200. It is assumed that the control unit 230 has confirmed in advance which port of the optical SW210 each port of the wavelength duplexer 261 (AWG) of the control unit 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 information that can obtain, for example, 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 the empty ports of the optical SW210 (step S2). Here, at least two ports, an uplink port and a downlink port, are assigned in the case of two cores, and at least one port is assigned in the case of both one core. The OPS300 registers information indicating that the assigned port is connected to the subscriber device 40-1 in the SW connection table. When the control unit 20 controls the subscriber device 400 with an optical signal, the optical SW control unit 320 of the OPS300 is located between the port assigned to the target subscriber device 40-1 and the port to which the control unit 230 is connected. The optical SW210 is controlled so as to transmit and receive an optical signal. When the subscriber device 40 is controlled by an optical signal via the optical SW210 and the monitoring unit 260, the optical SW210 is connected so as to pass through the monitoring unit 260, and the monitoring unit 260 or the communication unit is connected without the optical SW210. When it is not controlled by an optical signal or is not controlled by an optical signal, it may be left in that state if the connected port is unconnected by the optical SW210, or it may be left in that state if the connected port is cut off. May be good.

When the 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).
When measuring the propagation delay or the transmission distance with a register request, the functional unit that received the request, such as the control unit 230, the monitoring unit 260, the communication unit, etc., and the functional unit that uses the measured value, for example, received the request. If the control unit, monitoring unit, communication unit, etc. that are different from the above, the band allocation unit that notifies transmission permission, the opposite device, etc. use the value, measure it again with the function unit to be used, or measure the measured function unit and the function unit to be used. The propagation delay and transmission distance with and are used by adjusting the wavelength dispersion, polarization dispersion, and mode dispersion.
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. When the control unit 20 controls the subscriber device 400 with an optical signal, the optical SW 210 outputs a connection request input from the port connected to the subscriber device 40-1 to the output port to which the control unit 230 is connected. do. The input to the receiving port of the control unit may be via the monitoring unit 260. The control unit 230 receives the connection request from the reception port via the transmission line 531. The control unit 230 analyzes the input optical signal and confirms whether there is a problem with the initial set wavelength and the optical power (step S4).

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

The control unit 230 analyzes the optical signal received from the subscriber device 40-1 and outputs a connection request to the control unit 301 when it is confirmed that there is no problem. The 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 example, the address information of the destination is used as the information of the connection destination. 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 these 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 wavelength table between stations 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 unit 230 (step S5).

The other subscriber device 40, which is the communication destination of the subscriber device 40-1, is referred to 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 unit 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 unit 230 transmits wavelength information as follows. The wavelength variable transmitter 233 of the control unit 230 transmits a wavelength instruction set with the wavelength information selected by the wavelength control unit 310 by an optical signal having a wavelength indicating to the subscriber device 40-1. When transmitting the wavelength indication as an optical signal, the optical SW210 is transmitted from a port connected to the wavelength variable transmitter 233 of the control unit 20 or via a monitoring unit or from a port connected to the communication unit when the communication unit is used. The input optical signal is output to the 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 wavelength may be wavelength-branched in the middle of the path, or may differ from the setting as long as it reaches the subscriber device 40. If there is no duplexer or the like that demultiplexes according to the wavelength between the control unit 20 and the subscriber device 40, it is not necessary to change the wavelength of the signal to be transmitted. When the transmission wavelength is set in the instruction by the received optical signal, the subscriber device 40-1 sets the wavelength of the optical transceiver 41 according to the wavelength instruction (step S6). That is, the subscriber device 40-1 sets the wavelength of the optical transceiver 41 (wavelength variable 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 indication, the subscriber device 40-1 sets the optical transceiver 41 (tunable filter 453) to receive the wavelength signal of the reception wavelength.

When transmitting as an optical signal, 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 unit 230 via the optical SW210, the monitoring unit 260, or the communication unit, similarly to the request signal. Based on the received notification signal, the control unit 230 confirms whether the specified wavelength is set correctly, whether the output power is sufficient, and the like (step S7). The control unit 230 confirms whether or not the value of the notification signal is the value as instructed. Further, when the control unit 230 receives the optical signal, the control unit 230 may check the measured value of the optical signal. If it is determined that there is no problem as a result of the confirmation, the control unit 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 SW210 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 control unit 230 transmits the permission to start communication to the subscriber device 40-1. For example, it is assumed that the time required for route switching of the optical SW210 is known in advance. In this case, the control unit 230 actually communicates after the subscriber device 40-1 receives the permission to start communication for the time required for the optical SW210 to actually switch the route after receiving the route switching instruction. Wait until the start of communication, and then instruct to start communication. After the start of communication, the monitoring unit 260 of the GW 200 confirms the confirmation of the communication status between the opposite subscriber devices (step S9). The monitoring unit 260 notifies the OPS300 of the confirmation result. If the confirmation is NG, the control unit 230 or the OPS 300 performs a procedure for isolating the cause.

Further, the connection request transmitted by the subscriber device 40-1 and the control signal transmitted by the control unit 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) such as typified by AMCC can be used.

Further, the control unit or the OPS 300 informs the communication destination subscriber device 40 that the transmission wavelength of the subscriber device 40-1 is used as the reception wavelength of the communication destination subscriber device 40, and the reception wavelength of the subscriber device 40-1 is used. It is instructed to use the wavelength as the transmission wavelength of the communication destination subscriber device 40. For example, in the control unit 301 that controls the optical GW 200 in which the communication destination subscriber device 40 is housed, the wavelength control unit 310 transmits a wavelength instruction in which the reception wavelength and the transmission wavelength of the communication destination subscriber device 40 are set. Instruct the control unit 230. The communication destination subscriber device 40 receives a wavelength instruction from the control unit 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 wavelength of the optical transceiver 41 (wavelength variable light source 451) so as to transmit the optical signal by 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 453) to receive the wavelength signal of the reception wavelength.

Note that the optical access system 100 may send and receive information registered in the management DB 350 by the user application between the new subscriber device 40-1 and the control unit 301 without performing the user application in step S1. 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 control unit 301 via the control unit 230, for example, using an 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 exemplifying a case where the subscriber device 40-2 of FIG. 38 communicates.

First, the upstream optical signal output by the subscriber device 40-2 explaining the upstream 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 SW 210 via the transmission line 521. The optical SW210 connects the port to which the upstream optical signal is input from the wavelength combiner / demultiplexer 220 to another port corresponding to the route to the transfer destination on the route to the communication destination of the subscriber device 40-2. , Outputs an optical signal. When the wavelength is used as the destination information, the optical SW210 is connected to another port according to the transfer destination on the route to the communication destination specified by the wavelength assigned to the subscriber device 40-2 to transmit 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 connects the port to which the downlink optical signal is input from the duplexer 242 to another port corresponding to the wavelength, and outputs the optical signal. The wavelength combiner / demultiplexer 220 separates an optical signal input from the optical SW 210 via a transmission line 522 into an upstream optical signal and a downlink 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 unit 260 of the optical GW 200 receives the light branched by the branch unit 250. The light branched by the branch portion 250 is an optical signal transmitted and received by each subscriber device 40. The monitoring unit 260 monitors the signals transmitted and received by each subscriber device 40 by monitoring the received optical signal. When the monitoring unit 260 detects an abnormality such as a wavelength shift, a decrease in output, or a communication abnormality by monitoring, the monitoring unit 260 transmits an abnormality detection signal to the control unit 301. The optical SW control unit 320 of the control unit 301 controls the optical SW 210 so that the target subscriber device 40 is reconnected to the control unit 230. Then, the 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 SW 210 inputs the optical signal of the changed wavelength from the subscriber device 40, the optical SW 210 connects the input optical signal to the port specified by the subscriber device 40 by the wavelength before the change.

(First Configuration Example of Optical Access System 100)
Although the optical GW 200 shown in FIG. 38 performs wavelength division multiplexing, it is not necessary to perform wavelength division multiplexing as shown in FIGS. 43 and 44. FIG. 43 is a diagram showing a configuration example of the optical access system 101. The optical access system 101 shown in FIG. 43 differs from the optical access system 100 shown in FIG. 38 in that it includes a GW 201 instead of the GW 200. The difference between the GW 201 and the GW 200 is that the GW 201 is provided with the wavelength combiner / demultiplexer 243 and the branch portion 250a in place of the combiner 241 and the demultiplexer 242 and the branch portion 250. 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 or from any ground.

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 the upstream optical signal to another ground or higher network via the transmission line 503. Further, the wavelength combiner / demultiplexer 243 separates the downlink optical signal input from the other 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 optical signal to the port of the optical SW210 via the transmission line 551a, and inputs the branched downstream optical signal to the port of the optical SW210 via the transmission line 551b. The optical SW 210 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 duplexer 261 of the monitoring unit 260 receives the optical signal branched by the branching unit 250a.

(Second Configuration Example of Optical Access System 100)
FIG. 44 is a diagram showing a configuration example of the optical access system 102. The optical access system 102 shown in FIG. 44 differs from the optical access system 101 shown in FIG. 43 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 combiner / demultiplexer 244, a wavelength combiner / demultiplexer 245, and a branch portion 250b instead of the wavelength combiner / demultiplexer 243 and the branch 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 SW 210 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 optical 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 optical signal to the port of the optical SW210 via the transmission line 552b. The optical SW 210 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 optical signal branched by the branch portion 250b is input to the wavelength demultiplexer 261 of the monitoring unit 260.

The monitoring unit 260 described above has a receiver configuration including a wavelength duplexer 261 and an optical receiver 262 for each wavelength. The monitoring unit 260 may have a tunable optical receiver instead of this receiver configuration. The transmitter / receiver of the control unit may have a transmitter that does not have a tunable wavelength, or may have a receiver configuration that does not have a wavelength demultiplexer. An example of such a configuration will be described with reference to FIG. 45.

(Third configuration example of the optical access system 100)
FIG. 45 is a diagram showing a configuration example of the optical access system 103. The optical access system 103 shown in FIG. 45 differs from the optical access system 100 shown in FIG. 38 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 includes a control unit 235 and a monitoring unit 265 instead of the control unit 230 and the monitoring unit 260. The control unit 235 has an optical receiver 236 and an optical transmitter 237 that is not tunable. The monitoring unit 265 has a tunable optical receiver 266. The monitoring unit 265 may be replaced with any of the monitoring units 60 to 60h described above.

(Fourth Configuration Example of Optical Access System 100)
Further, the monitoring unit may be connected via an optical SW different from the optical SW described above. An example of such a configuration will be described with reference to FIG. 46. FIG. 46 is a diagram showing a configuration example of the optical access system 104. The optical access system 104 shown in FIG. 46 differs from the optical access system 103 shown in FIG. 45 in that the optical GW 204 is provided 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 unit 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 the transmission line. 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 unit 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. It should be noted that instead of using the small optical SW, monitoring units may be prepared for the number of connected grounds to monitor signals transmitted to and received from all grounds for each ground.

In this configuration example, communication is performed between a plurality of subscriber devices connected to the same optical GW using a folded transmission line. In the following, the differences from the above configuration example will be mainly described.

(Fifth configuration example of the optical access system 100)
FIG. 47 is a diagram showing a configuration example of the optical access system 105. The optical access system 105 shown in FIG. 47 differs from the optical access system 103 shown in FIG. 45 in that the optical GW 205 is provided in place 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 duplexer 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 SW 210 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 SW 210 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 above configuration example, 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 this configuration example, another set that is the same as the combination of the combiner 241 and the duplexer 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 combiner 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 SW 210 as a downlink signal. By connecting this folded signal to another subscriber device 40 in the optical SW 210, back communication, that is, communication between the subscriber devices 40 connected to the same optical GW 205 becomes possible.

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 is connected. It is assumed that the transmission line 542 is connected to the duplexer 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 upstream 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 optical 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 kth upstream 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 kth downlink port corresponding to the ground A. The optical SW control unit 320 sets a path in the optical SW 210 so that the optical 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.

(Sixth Configuration Example of Optical Access System 100)
Other configurations of this configuration example will be described with reference to FIGS. 48 and 49. FIG. 48 is a diagram showing a configuration example of the optical access system 106. The optical access system 106 shown in FIG. 48 differs from the optical access system 105 shown in FIG. 47 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 it does not have a combiner 247 and a demultiplexer 248, and directly connects the upstream port and the downstream port of the optical SW210 for ground A without wavelength division multiplexing by a transmission line 548. As a result, the signal is folded back.

(7th configuration example of the optical access system 100)
FIG. 49 is a diagram showing a configuration example of the optical access system 107. The optical access system 107 shown in FIG. 49 differs from the optical access system 105 shown in FIG. 47 in 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. 47. The power splitter splits the optical signal demultiplexed by the demultiplexer 248 into a plurality of segments 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.

(Eighth configuration example of the optical access system 100)
The optical access system of this configuration example performs multicast communication. In this configuration example, the difference will be mainly described.

First, multicast for downlink communication will be described with reference to FIG. FIG. 50 is a diagram showing a configuration example of the optical access system 108. The optical access system 108 shown in FIG. 50 differs from the optical access system 107 shown in FIG. 49 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 again to the optical SW210 as an upstream 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 a result, the optical signal input to the optical SW210 by folding 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 them to the transmission line 547. The optical signal output to the transmission line 547 is branched into a plurality of optical 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.

(Ninth configuration example of the optical access system 100)
Subsequently, multicast for uplink communication will be described with reference to FIG. 51. FIG. 51 is a diagram showing a configuration example of the optical access system 109. The optical access system 109 shown in FIG. 51 differs from the optical access system 103 shown in FIG. 45 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 for connecting 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 to connect the port for inputting the upstream optical signal from the ground A 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 optical 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.

(10th Configuration Example of Optical Access System 100)
Subsequently, with reference to FIG. 52, a configuration in which point-to-multipoint communication including uplink communication is performed while performing downlink communication multicast will be described. FIG. 52 is a diagram showing a configuration example of the optical access system 110. The optical access system 110 shown in FIG. 52 differs from the optical access system 103 shown in FIG. 45 in that the optical GW 2010 is provided in place 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 for connecting a return port to the optical SW210, and a

power splitter

272, 273. The power splitter 272 is connected to the optical SW210 via the transmission line 581 and the plurality of transmission lines 582. The power splitter 273 is connected to the optical SW210 via a plurality of transmission lines 583 and a 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 to connect the port for inputting the downlink optical signal from the ground C 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 an upstream 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 optical 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 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 SW 210 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 SW 210 outputs an optical signal input from the transmission line 575 to a combiner 241 connected to the ground C according to the wavelength.

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

(Eleventh configuration example of the optical access system 100)
In this configuration example, communication is performed without separating the uplink signal and the downlink signal. In the following, the differences from the above-mentioned configuration examples will be mainly described.

FIG. 53 is a diagram showing a configuration example of the optical access system 111. The optical access system 111 shown in FIG. 53 differs from the optical access system 105 shown in FIG. 47 in that the optical GW 2011 is provided in place of the optical GW 205. The difference between the optical GW 2011 and the optical GW 205 is that the optical GW 2011 does not have the wavelength combiner / demultiplexer 220, and the wavelength combiner / demultiplexer 249 and the branch portion 253 are replaced with the combiner 241 and the demultiplexer 242 and the branch portion 250. 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 downlink 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 SW 210 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 the transmission line 534, and is connected to the control unit 235 by the transmission line 531 and the 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 unit 235 via the transmission line 531. The wavelength combiner / demultiplexer 238 outputs a downlink optical signal input from the control unit 235 via the transmission line 533 to the optical SW210 via the transmission line 534.

As described above, the optical GW 2011 does not have a wavelength combiner / demultiplexer between the optical SW210 and the subscriber device 40, and has a configuration that does not separate the uplink signal and the downlink signal. This makes it possible to greatly reduce the number of ports used for the optical SW210 and greatly reduce the amount of information to be managed. Further, as shown in FIG. 54, the portion for separating the optical signal to the monitoring unit 265 may be configured as shown in FIG. 44.

(12th configuration example of the optical access system 100)
FIG. 54 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. 54 includes a branch portion 255 in place of the branch portion 253 included in the optical GW 2011 shown in FIG. 53. 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 the downlink optical signal input from the wavelength combiner / demultiplexer 257 via the 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 the upstream optical signal 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 the downlink optical signal to the port of the optical SW210 via the transmission line 587. The optical SW 210 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. 53 performs wavelength division multiplexing, but as shown in FIG. 55, a configuration in which signals transmitted to each station building (ground B or ground C) are transmitted through individual transmission lines without wavelength division multiplexing. May be.

(13th Configuration Example of Optical Access System 100)
FIG. 55 is a diagram showing a configuration example of the optical access system 113. The optical access system 113 shown in FIG. 55 differs from the optical access system 101 shown in FIG. 43 in that the optical GW 2013 is provided 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 combiner / demultiplexer 220 and the wavelength combiner / demultiplexer 243, and instead of the control unit 230 and the monitoring unit 260, the control unit 235 shown in FIG. 53. The point is that the wavelength combiner / demultiplexer 238 and the monitoring unit 265 are provided. The port of the optical SW 210 connected to the transmission line 503 outputs an upstream optical signal and inputs a downlink optical signal.

(14th Configuration Example of Optical Access System 100)
Further, the branch portion 250a in the optical GW 2013 may be configured as shown in FIG. 56. FIG. 56 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. 56 has the same configuration as the branch portion 255 shown in FIG. 54 in place of the branch portion 250a included in the optical GW 2013 shown in FIG. 55.

(15th Configuration Example of Optical Access System 100)
This configuration example enables control of the subscriber device during communication. In the following, the differences from the above-mentioned configuration examples will be mainly described.

FIG. 57 is a diagram showing a configuration example of the optical access system 115. The optical access system 115 shown in FIG. 57 differs from the optical access system 104 shown in FIG. 46 in that the optical GW 2015 is provided in place of the optical GW 204. The difference between the optical GW 2015 and the optical GW 204 is that the monitoring unit 267 is connected to the optical SW211 instead of the monitoring unit 265.

The monitoring unit 267 includes a tunable receiver 268 and a tunable transmitter 269. The monitoring unit 267 can receive an optical signal of an arbitrary wavelength by the wavelength variable receiver 268, and can transmit an optical signal of an arbitrary wavelength by the wavelength variable transmitter 269. Further, the optical GW 2015 includes a control unit 235. When the subscriber device 40 is connected, the optical GW 2015 uses the control unit 235 to perform connection processing (registration, wavelength allocation, etc.) of the subscriber device 40, and starts normal communication.

Here, consider a state in which the subscriber device 40-1 is connected to the ground B. The subscriber device 40-1 cannot communicate with the control unit 235 because it is in a state of performing normal communication. Therefore, by providing a monitoring unit 267 connected to the optical SW211 which is a small optical SW, it is possible not only to monitor the communication status of the subscriber device 40-1 but also to instruct various settings of the subscriber device 40-1. It becomes. 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 input optical signal to the monitoring unit 267. The monitoring unit 267 monitors the optical signal received by the tunable receiver 268 from the optical SW211 and further receives a control signal superimposed on the received optical signal. The tunable transmitter 269 of the monitoring unit 267 transmits a control signal to the subscriber device 40 as an optical signal. The optical SW211 outputs an optical signal input from the tunable transmitter 269 to a port corresponding to the wavelength. The power splitter 251 combines the control signal input 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 unit 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.

(16th Configuration Example of Optical Access System 100)
In this configuration example, the optical signal extracted from the optical SW is subjected to electrical processing. In the following, the differences from the above-mentioned configuration examples will be mainly described.

FIG. 58 is a diagram showing a configuration example of the optical access system 116. The optical access system 116 shown in FIG. 58 differs from the optical access system 105 shown in FIG. 47 in that the optical GW 2016 is provided in place of the optical GW 202. The difference between the optical GW 2016 and the optical GW 202 is that the electric processing unit 600 is connected.

The electric processing 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. The electric processing unit 600 has an O / E conversion unit 610, a processing execution unit 620, and an E / O conversion unit 630. The O / E conversion unit 610 corresponds to the O / E conversion unit 85 in FIG. The O / E conversion unit 610 converts the optical signal input from the optical SW210 into an electric signal and outputs it to the processing execution unit 620. The processing execution unit 620 corresponds to the processing execution unit 86 and the storage unit 88 in FIG. The processing execution unit 620 performs electrical processing on the electric signal converted by the O / E conversion unit 610 by reading a program from a storage unit (not shown) such as a CPU or an accelerator and executing the program. 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, a code error correction such as FEC. The E / O conversion unit 630 corresponds to the E / O conversion unit 87 in FIG. The E / O conversion unit 87 converts an electric signal into an optical signal and outputs it to the optical SW210. The O / E conversion unit 610 and the E / O conversion unit 630 are, for example, tunable wavelength transmitters and receivers.

In FIG. 58, the subscriber device 40-M is a PON ONU. 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 processing execution unit 620 of the electric processing unit 600 is equipped with an error correction function, an OLT function, and the like.

The wavelength control unit 310 notifies the processing execution unit 620 of the determination conditions for determining the signal to be electrically processed and the type of electrical processing to be performed on the signal. The processing execution unit 620 stores information on the determination conditions and the type of electrical processing notified from the wavelength control unit 310.

For example, in step S5 of FIG. 42, the wavelength control unit 310 performs communication between the subscriber device 40 of the transmission source of the connection request (hereinafter referred to as the request source subscriber device 40) and the communication destination subscriber device 40. Determine whether to perform electrical processing. The wavelength control unit 310 depends on the distance between the opposite requesting subscriber device 40 and the communication destination subscriber device 40, the service provided to the requesting source subscriber device 40 or the communication destination subscriber device 40, and the like. It is determined whether or not to perform electric treatment, and if so, what kind of electric treatment is to be performed. When the wavelength control unit 310 determines that the signal from the requesting subscriber device 40 to the communication destination subscriber device 40 is subjected to electrical processing (hereinafter referred to as transmission signal electrical processing), the first transmission is performed from among the available wavelengths. Allocate a credit wavelength and a second transmission wavelength. Further, when the wavelength control unit 310 determines that the signal addressed to the requesting subscriber device 40 from the communication destination subscriber device 40 is to be electrically processed (hereinafter, received signal electrical processing), the wavelength control unit 310 is selected from among the available wavelengths. (1) A wavelength for reception and a wavelength for second reception are assigned.

The first transmission wavelength is a wavelength for routing an optical transmission signal, which is an optical signal from the requesting subscriber device 40 to the communication destination subscriber device 40, to the electric processing unit 600. The second transmission wavelength is a wavelength for routing the transmission signal subjected to the transmission signal electrical processing by the electric processing unit 600 to the port corresponding to the communication destination subscriber device 40. The first reception wavelength is a wavelength for routing a received signal, which is an optical signal from the communication destination subscriber device 40 to the requesting subscriber device 40, to the electric processing unit 600. The second reception wavelength is a wavelength for routing the received signal, which has been electrically processed by the electric processing unit 600, to the port corresponding to the requesting subscriber device 40. The first transmission wavelength and the second transmission wavelength may be the same wavelength, or the first reception wavelength and the second reception wavelength may be the same wavelength.

When the wavelength control unit 310 determines that the transmission signal electrical processing is performed, the wavelength control unit 310 sets the information of the first transmission wavelength as the transmission wavelength in the wavelength instruction to be transmitted to the requesting subscriber device 40. Further, when the wavelength control unit 310 determines that the reception signal electrical processing is performed, the wavelength control unit 310 sets the information of the second reception wavelength as the reception wavelength in the wavelength instruction to be transmitted to the requesting subscriber device 40.

When the OPS 300 determines that the transmission signal electrical processing is performed, the OPS 300 instructs the communication destination subscriber device 40 to use the reception wavelength. Further, when the OPS 300 determines that the received signal is electrically processed, the OPS 300 instructs the communication destination subscriber device 40 to use the first transmission wavelength for the transmission wavelength. For example, in the control unit 301 that controls the optical GW 200 in which the communication destination subscriber device 40 is housed, the wavelength control unit 310 transmits a wavelength instruction in which the reception wavelength and the transmission wavelength of the communication destination subscriber device 40 are set. Instruct the control unit 230.

Further, when the wavelength control unit 310 determines that the transmission signal electrical processing is performed, the determination condition for determining that the transmission signal is from the requesting subscriber device 40 to the communication destination subscriber device 40, and the transmission signal. Generates first instruction information in which the type of transmission signal electrical processing applied to the above, the first transmission wavelength, and the second transmission wavelength are associated with each other. Further, when the wavelength control unit 310 determines that the received signal is electrically processed, the determination condition for determining that the signal is received from the communication destination subscriber device 40 to the requesting subscriber device 40, and the received signal. The type of the received signal electrical processing applied to the above, the first reception wavelength, and the second instruction information associated with the second reception wavelength are generated. The wavelength control unit 310 transmits the electric processing execution instruction in which the generated first instruction information and the second instruction information are set to the electric processing unit 600.

When the optical SW control unit 320 performs transmission signal electrical processing, the optical SW control unit 320 inputs the transmission signal of the first transmission wavelength transmitted by the requesting subscriber device 40 to the electrical processing unit 600 for the second transmission. The optical SW210 is controlled so that the transmission signal of the wavelength is output to the transmission line 541 corresponding to the communication destination subscriber device 40. Further, when the optical SW control unit 320 performs the received signal electric processing, the optical SW control unit 320 sends the received signal of the first transmission wavelength input from the transmission line 542 corresponding to the communication destination subscriber device 40 to the electric processing unit 600 and the electric processing unit. The optical SW210 is controlled so that the reception signal of the second transmission wavelength input from 600 is output to the transmission line 522 corresponding to the requesting subscriber device 40.

For example, it is assumed that the optical signal between the subscriber device 40-2 and the communication destination subscriber device 40 of the ground C is subjected to transmission signal electrical processing and reception signal electrical processing. The transmission signal of the first transmission wavelength transmitted by the subscriber device 40-2 is output to the electric processing unit 600 via the optical SW210. The O / E conversion unit 610 converts the transmission signal input from the optical SW210 into an electrical signal. When the processing execution unit 620 refers to the predetermined information included in the transmission signal converted into the electric signal and determines that the determination condition included in the first instruction information is satisfied, the transmission signal is subjected to the determination condition. Performs electrical processing of the transmission signal corresponding to. For example, the processing execution unit 620 performs error correction such as FEC (forward error correction). The E / O conversion unit 630 converts the transmission signal of the electric signal corrected by the processing execution unit 620 into an optical signal having the second transmission wavelength indicated by the first instruction information, and outputs the optical signal to the optical SW210. The optical SW210 outputs a transmission signal having a second transmission wavelength to a transmission line 541 corresponding to the ground C. By performing error correction, the transmission characteristics are improved.

The optical SW210 outputs the reception signal of the first reception wavelength input from the transmission line 542 corresponding to the communication destination subscriber device 40 of the ground C to the electric processing unit 600. The O / E conversion unit 610 converts the received signal input from the optical SW210 into an electric signal. When the processing execution unit 620 refers to the predetermined information included in the transmission signal converted into the electric signal and determines that the determination condition included in the second instruction information is satisfied, the processing execution unit 620 determines the determination condition in the received signal. Received signal electrical processing corresponding to. The E / O conversion unit 630 converts the reception signal of the electric signal subjected to the reception signal electric processing by the processing execution unit 620 into an optical signal having the second reception wavelength indicated by the second instruction information, and outputs the reception signal to the optical SW210. The optical SW210 outputs the transmission signal of the second reception wavelength to the transmission line 522 corresponding to the subscriber device 40-2.

FIG. 59 is a diagram showing a configuration example of the optical access system 116 when the electric processing unit 600 performs signal multiplexing. The electric processing unit 600 has O / E conversion units 610-1 and 610-2 as a plurality of O / E conversion units 610.

The upstream optical signal of the subscriber device 40-3 and the upstream optical signal of the subscriber device 40-M are connected to the electric processing unit 600 via the optical SW210. The OLT function is mounted on the electric processing unit 600. The processing execution unit 620 of the electric processing unit 600 processes the electric stage of the OLT function. A plurality of subscriber devices 40 are connected to the OLT. The processing execution unit 620 to which the OLT function is implemented collectively manages the subscriber devices 40.

The O / E conversion unit 610-1 converts the upstream optical signal of the subscriber device 40-3 input from the optical SW210 into an electric signal and outputs it to the processing execution unit 620. The O / E conversion unit 610-2 converts the upstream optical signal of the subscriber device 40-M input from the optical SW210 into an electric signal and outputs it to the processing execution unit 620. The processing execution unit 620 collects the upstream electric signals transmitted from the subscriber device 40-3 and the subscriber device 40-M into one, and outputs the signal to the E / O conversion unit 630. The E / O conversion unit 630 converts the upstream electric signal output by the processing execution unit 620 into an optical signal according to the wavelength instructed by the control unit 230, and outputs the optical signal to the optical SW210. The optical SW210 outputs the upstream optical signal input from the electric processing unit 600 to the transmission line 541 corresponding to the ground C. In this way, the electric processing unit 600 receives the plurality of optical signals dropped by the optical GW 2016 and converts them into electric signals, multiplexes the signals having the same target ground by the multiplex circuit, and then converts them into optical signals again. Then, it is transmitted to the optical GW2016. As a result, the transmission speed can be increased. 58 and 59 are examples in which one electric processing unit is provided, but a configuration having a plurality of electric processing units may be used.

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.

(17th configuration example of the optical access system 100)
This configuration example is a form in which different optical SWs to the ground are connected by a ring. In the following, the differences from the above-mentioned configuration examples will be mainly described.

FIG. 60 is a diagram showing a configuration example of the optical access system 117. The optical access system 117 is configured by connecting three or more different optical SW212s to the ground in a ring via an optical communication network 30. In the example shown in FIG. 60, the optical access system 117 is configured by ring-connecting the optical SW212a which is the optical SW212 of the ground A, the optical SW212b which is the optical SW212 of the ground B, and the optical SW212c which is the optical SW212 of the ground C. Is. The path between the optical SW212a and the optical SW212b in the optical communication network 30 is described as a path P31, the path between the optical SW212b and the optical SW212c in the optical communication network 30 is described as a path P32, and the optical in the optical communication network 30 is described as a path P32. The path between SW212c and optical SW212a is referred to as path P33. Further, one or more subscriber devices 40a are connected to the optical SW212a, one or more subscriber devices 40b are connected to the optical SW212b, and one or more subscriber devices 40c are connected to the optical SW212c. ..

As the optical SW212, the above-mentioned optical SW or optical GW is used. For example, the ground B in FIGS. 6 to 10, 38, and 43 to 59 is defined as the counterclockwise ground in the ring shown in FIG. 60, and the ground C in FIGS. 6 to 10, 38, and 43 to 59. Is a clockwise ground in the ring shown in FIG. 60. In this case, the light SW212a of the ground A is connected to the light SW212b of the ground B by the path P31, and the light SW212b of the ground B to the light SW212a of the ground A are connected to the light SW212-c of the ground C and the path P33. Connected via. Further, the light SW212a of the ground A is connected to the light SW212c of the ground C by the path P33, and the light SW212c of the ground C is connected to the light SW212a of the ground A via the path P32, the light SW212b of the ground B, and the path P31. The light.

Therefore, a clockwise path connecting the light SW212a of the ground A to the light SW212b of the ground B via the light SW212c of the ground C, with the counterclockwise connection from the light SW212a of the ground A to the light SW212b of the ground B as a preliminary system. It is also possible to connect with, and the reverse rotation is also possible. Similarly, using the clockwise connection from the light SW212a of the ground A to the light SW212c of the ground C as a preliminary system, the light SW212-a of the ground A is connected to the light SW212c of the ground C via the light SW212b of the ground B in the counterclockwise direction. It is possible to connect by the route of, and the reverse rotation is also possible.

Further, as a preliminary system for connecting the subscriber devices 40a connected to the optical SW212a to the ground A, a counterclockwise route via the path P31, the optical SW212b to the ground B, the route P32, the optical SW212c to the ground C, and the path P33. Alternatively, it is also possible to use a counterclockwise route via the route P33, the light SW212c of the ground C, the route P32, the light SW212b of the ground B, and the route P31.

For example, in FIG. 14, the medium-distance line P2 may be a left-handed route of the ring, and the medium-distance line P3 may be a right-handed route of the ring. Further, any one of the grounds # 1 to # q in FIGS. 16 and 19 may be used as the left-handed ground of the ring, and the other one may be used as the right-handed ground of the ring. Further, when FIGS. 27 and 28 are optical SW1010s in one GW, any one of uplink # 11 to uplink # 43 is used as a counterclockwise path of the ring, and the other one. May be used as a clockwise route for the ring. The route not selected as the ring route here may be a ring route similar to the route selected as the ring route, may be an oblique line other than the ring, or may be connected to the subscriber device 40. It may be connected to another optical SW1010 shown in FIGS. 27 and 28.

In the above, as a basic configuration, when performing multicast, as shown in FIG. 4 or FIG. 5, multicast in the upstream direction or the downlink direction is realized via the return transmission line. For example, in the example shown in FIG. 4, in order to realize uplink multicast, an optical signal output from port 11-2 of the optical SW10c is input to another port 11-2 via a return transmission path, and optical is used. The SW10c outputs this input optical signal to the port 11-1 to which the 1 × N power splitter 71 is connected. Then, the optical signal output from the port 11-1 is distributed by the power splitter 71 and input to the plurality of other ports 11-1, thereby realizing the uplink multicast. However, in such a configuration, when performing multicast, it is necessary to use a port for return, so that the number of ports in use may increase. Such a problem occurs not only when performing multicast routing but also when performing broadcast routing. Therefore, in the following embodiment, a configuration for reducing the number of ports when performing multicast or broadcast routing will be described. In the following description of the embodiment, the description of the control unit 20 and the OPS 300 may be omitted in the drawings, but in the optical access system, the wavelength is set and the optical SW connection is set by the control unit 20 and the OPS 300.

(First Embodiment)
In the following embodiments including the present embodiment, the uplink multicast from the subscriber device 40a connected to the port 11-1 to the

subscriber device

40b or 40c connected to the port 11-2 or the uplink will be mainly described. If port 11-1 and port 11-2 are exchanged line-symmetrically with the central optical SW210, the

subscriber device

40b or 40c connected to the uplink or port 11-2 to the subscriber device 40a connected to port 11-1 or the like. It becomes a multicast to. In broadcasting, the processing flow is the same as in multicast.

FIG. 61 is a diagram showing a configuration example of the optical GW200a in the optical access system of the first embodiment. FIG. 61 describes a case where the uplink optical signals transmitted from the subscriber devices 40a-1 and 40a-2 located at the ground A are multicast. Here, in the description, as shown in FIG. 61, it is assumed that the ports connected by the dotted lines are connected inside the optical SW210a. The connection between the ports is executed by an optical SW control unit 320 (not shown).

The optical GW200a turns back the optical signal output from the port 11-2 without going through the optical SW210a-1 and inputs it to the power splitter 71 connected to the port 11-1. This enables multicast. FIG. 61 shows two configurations, that is, a configuration in which an optical signal is returned without passing through the optical SW210a-1 via another optical switch and a configuration in which the optical signal does not pass through the other optical switch. Hereinafter, each configuration will be described.

(Configuration that does not go through other optical switches)
In a configuration that does not pass through another optical switch, the optical GW200a has an optical SW210a-1, a transmission line 2101, and a power splitter 71-1. The transmission line 2101 connects the output side port (for example, port 11-2-1) of the optical SW210a-1 and the power splitter 71-1 via the outside of the optical SW210a-1. Via the outside of the optical SW210a-1 means not passing through the inside (between ports) of the optical SW210a-1. That is, the transmission line 2101 is a transmission line provided outside the optical SW210a-1 and directly connects the port 11-2-1 and the power splitter 71-1. The transmission line 2101 is, for example, an optical fiber. The power splitter 71-1 distributes the input optical signal to a plurality of the input optical signals, and inputs the distributed plurality of optical signals to different ports 11-1. A new power splitter may be provided between the power splitter 71-1 and the port 11-1. In this case, the power splitter 71-1 distributes the input optical signal to a plurality of the input optical signals, and a part or all of the distributed optical signals is input to the port 11-1 via the power splitter.

The processing flow when the optical GW200a is configured not to pass through another optical switch will be described. In FIG. 61, the optical GW 200a outputs an optical signal transmitted by the subscriber device 40a-1 and input to the port 11-1-1 from the port 11-2-1. The optical signal output from port 11-2-1 is input to the power splitter 71-1 connected to a plurality of ports 11-1-n to 11-1- (n + 2) via the transmission line 2101. .. For example, in FIG. 61, the power splitter 71-1 is connected to ports 11-1-3 to 11-1-5.

The power splitter 71 distributes the input optical signal and inputs it to a plurality of ports 11-1-3 to 11-1-5. The optical SW210a-1 outputs optical signals input from these plurality of ports 11-1-3 to 11-1-5 to different ports 11-2-3 to 11-2-5, respectively. Two-way communication is also possible. The optical signal in the downlink direction is routed in the reverse direction to the uplink direction.
In this case, the upstream direction is one-to-many communication, and the downstream direction is many-to-one communication. In this case, the power splitter 71 is used as a turnout. The power splitter 71 used here has an H × I input / output port. H and I are integers of 1 or more, and have a relationship of H ≦ I. When H = 1 and I = 2, the power splitter 71 branches the optical signal going up, for example, and multiplexes the optical signal going down. In the example of FIG. 61, the power splitter 71 branches the input optical signal and inputs it to the plurality of ports 11-1-3 to 11-1-5, and the plurality of ports 11-1-3-11-1-1. The optical signals output from each of -5 are multiplexed and output to the transmission line 2101.

When a multicast transmission request is made from the subscriber device 40a-1 in order to realize the above processing, the optical SW control unit 320 connects to the port 11-1-1 to which the subscriber device 40a-1 is connected. , Connect to port 11-2-1 to which the power splitter 71-1 for performing multicast is connected. As a result, the optical signal transmitted from the subscriber device 40a-1 is output from the port 11-2-1. Further, the optical SW control unit 320 is connected to the ports 11-1-3 to 11-1-5 to which the power splitter 71-1 is connected, and the port 11-2 according to the transfer destination on the route to the communication destination. In FIG. 61, it is connected to 11-2-3 to 11-2-5). As a result, each of the optical signals branched by the power splitter 71-1 is output from the port 11-2 to which the destination subscriber device 40b is connected. With such a configuration, the optical signal is folded back to enable multicast.

In the case of downlink multicast, it is as follows.
The optical GW200a has an optical SW210a-1, a transmission line, and a power splitter. The transmission line connects the output side port (for example, port 11-1-1) of the optical SW210a-1 and the power splitter via the outside of the optical SW210a-1. The transmission line is a transmission line that directly connects the port 11-1-1 and the power splitter. The transmission line is, for example, an optical fiber. The power splitter distributes the input optical signal to a plurality of the input optical signals, and inputs the divided plurality of optical signals to different ports 11-2. The optical SW210a-1 outputs an optical signal input to the port 11-2-1 from the port 11-1-1. The optical signal output from port 11-1-1 is input to a power splitter connected to a plurality of ports 11-2-n to 11-2- (n + 2) via a transmission line. For example, the power splitter is connected to ports 11-2-3 to 11-2-5.
The power splitter distributes the input optical signal and inputs it to a plurality of ports 11-2-3 to 11-2-5. The optical SW210a-1 outputs optical signals input from these plurality of ports 11-2-3 to 11-2-5 to different ports 11-1-3 to 11-1-5, respectively.

(Configuration via other optical switches)
In the configuration via another optical switch, the optical GW200a has an optical SW210a-1, an optical SW210a-2, a transmission line 2102, and a power splitter 71-2. The optical SW210a-2 is connected to a port on the output side of the optical SW210a-1 (for example, port 11-2-q). The transmission line 2102 connects the optical SW210a-2 and the power splitter 71-2 via the outside of the optical SW210a-1. The optical SW210a-2 outputs an optical signal output from the port 11-2 on the output side of the optical SW210a-1 to the power splitter 71-2 via the transmission line 2102. The power splitter 71-2 distributes the input optical signal to a plurality of the input optical signals, and inputs the distributed plurality of optical signals to different ports 11-1. A new power splitter may be provided between the power splitter 71-2 and the port 11-1. In this case, the power splitter 71-1 distributes the input optical signal to a plurality of the input optical signals, and a part or all of the distributed optical signals is input to the port 11-1 via the power splitter. The optical GW 200a may have either a configuration that does not pass through another optical switch or a configuration that passes through another optical switch, or may have both.

The flow of processing when the optical GW200a is configured to pass through another optical switch will be described. In FIG. 61, the optical GW 200a outputs an optical signal transmitted by the subscriber device 40a-2 and input to the port 11-1-p from the port 11-2-q. The optical signal output from port 11-2-1 is input to the optical SW210a-2. The optical SW210a-2 is a power for connecting an optical signal output from the port 11-2-q to a plurality of ports 11-1- (P-2) to 11-1-P via a transmission line 2102. Output to splitter 71-2.

The power splitter 72 distributes the input optical signal and inputs it to a plurality of ports 11-1- (P-2) to 11-1-P. The optical SW210a-1 inputs optical signals input from these plurality of ports 11-1- (P-2) to 11-1-P, respectively, from different ports 111-1- (Q-2) to 11-1-Q. Output to. Two-way communication is also possible. The optical signal in the downlink direction is routed in the reverse direction to the uplink direction. In this case, the upstream direction is one-to-many communication, and the downstream direction is many-to-one communication. In this case, the power splitter 71 is used as a turnout. The power splitter 71 used here has an H × I input / output port. When H = 1 and I = 2, the power splitter 71 branches the optical signal going up, for example, and multiplexes the optical signal going down. In the example of FIG. 61, the power splitter 71 branches the input optical signal and inputs it to a plurality of ports 11-1- (Q-2) to 11-1-Q, and a plurality of ports 11-1-( The optical signals output from each of Q-2) to 11-1-Q are multiplexed and output to the transmission line 2102.

When a multicast transmission request is made from the subscriber device 40a-2 in order to realize the above processing, the optical SW control unit 320 connects to the port 11-1-p to which the subscriber device 40a-2 is connected. , Connect to port 11-2-q to which the power splitter 71-2 for performing multicast is connected. As a result, the optical signal transmitted from the subscriber device 40a-2 is output from the port 11-2-q. Further, the optical SW control unit 320 has ports 11-1- (P-2) to 11-1-P to which the power splitter 71-2 is connected, and ports corresponding to the transfer destination on the path to the communication destination. 11-2 (11-2- (Q-2) to 11-2-Q in FIG. 61) is connected. As a result, each of the optical signals branched by the power splitter 71-2 is output from the port 11-2 to which the destination subscriber device 40c is connected. With such a configuration, the optical signal is folded back to enable multicast to the destination.

In the case of downlink multicast, it is as follows.
The optical GW200a has an optical SW210a-1, an optical SW210a-2, a transmission line, and a power splitter. The optical SW210a-2 is connected to a port on the output side of the optical SW210a-1 (for example, port 11-1-q). The transmission line connects the optical SW210a-2 and the power splitter via the outside of the optical SW210a-1. The optical SW210a-2 outputs an optical signal output from a port on the output side of the optical SW210a-1 to a power splitter via a transmission line. The power splitter distributes the input optical signal to a plurality of the input optical signals, and inputs the distributed optical signals to different ports 11-2. The optical GW 200a may have either a configuration that does not pass through another optical switch or a configuration that passes through another optical switch, or may have both.

According to the optical GW200a configured as described above, the port of the optical SW210a-1 is not used as a return route when performing multicast or broadcast routing. Therefore, even when routing is performed, the number of routes inside the optical SW210a-1 is reduced by one route, that is, one port each of ports 11-1-p and 11-2-q. Therefore, it is possible to transmit the optical signal according to the transfer destination on the route to the communication destination while reducing the number of ports used when performing multicast or broadcast routing in the optical SW210a-1.

In the first embodiment, a power splitter is mainly used, but in the case of multicast demultiplexing for each wavelength (effectively, unicast demultiplexed by wavelength), a demultiplexer may be used.

(Second embodiment)
In the first embodiment, the configuration is shown in which the optical signal once output from the port 11-2 via the optical SW is folded back via the outside of the optical SW. In this case, in order to return the optical signal, it is necessary to transmit the optical signal once between the ports of the optical SW, so that the number of ports cannot be used. Therefore, in the second embodiment, a configuration in which the number of ports for performing multicast is reduced as compared with the first embodiment will be described. In broadcasting, the processing flow is the same as in multicast.

FIG. 62 is a diagram showing a configuration example of the optical GW200b in the optical access system of the second embodiment. FIG. 62 describes a case where the uplink optical signals transmitted from the subscriber devices 40a-1 and 40a-2 located at the ground A are multicast. Here, in the description, as shown in FIG. 62, it is assumed that the ports connected by the dotted lines are connected inside the optical SW210b. The connection between the ports is executed by an optical SW control unit 320 (not shown).

The optical GW200b distributes the optical signals output by the subscriber device 40a-1 into a plurality of units, and inputs the distributed plurality of optical signals to different ports 11-1. This reduces the number of ports in a set for folding back optical signals and enables multicast. The optical GW 200b has power splitters 71-1 and 71-2. The optical GW 200b may have only one of the power splitter 71-1 or the power splitter 71-2, or may have both.

In FIG. 62, the power splitter 71-1 distributes the optical signal output by the subscriber device 40a-1 into a plurality of units, and distributes the distributed optical signals to different ports 11-1 (port 11-1 in FIG. 62). Enter in -3 to 11-1-5). The power splitter 71-1 is connected to the subscriber device 40a-1 via the transmission line 2103. The power splitter 71-2 distributes the optical signals output by the subscriber device 40a-2 into a plurality of units, and distributes the distributed optical signals to different ports 11-1 (11-1- (P-2 in FIG. 62)). ) ~ 11-1-P). The power splitter 71-2 is connected to the subscriber device 40a-2 via the transmission line 2104. A new power splitter may be provided between the power splitter 71-1 and the port 11-1, and between the power splitter 71-2 and the port 11-1. In this case, the power splitters 71-1 and 71-2 distribute the input optical signal to a plurality of the input optical signals, and input a part or all of the distributed optical signals to the port 11-1 via the power splitter.

As described above, in the second embodiment, the power splitter 71 and the power splitter 72 are provided in the stage before the optical signal is input to the port 11-1, and the optical signal output from the subscriber device 40a is multicast. The optical SW210b 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 optical signal in the downlink direction is routed in the reverse direction to the uplink direction. In this case, the power splitter 71 is used as a turnout. The power splitter 71 used here has an H × I input / output port. When H = 1 and I = 2, the power splitter 71 branches the optical signal going up, for example, and multiplexes the optical signal going down. In the example of FIG. 62, the power splitter 71 branches the input optical signal and inputs it to the plurality of ports 11-1-3 to 11-1-5, and the plurality of ports 11-1-3-11-1-1. -5 The optical signals output from each are multiplexed and output to the subscriber device 40a-1.

When a multicast transmission request is made from the subscriber device 40a in order to realize the above processing, the optical SW control unit 320 is connected to the power splitter 71 to which the subscriber device 40a of the transmission request source is connected. The port 11-1 is connected to the port 11-2 corresponding to the transfer destination on the route to the communication destination. As a result, the optical signal transmitted from the subscriber device 40a is branched by the power splitter 71, and the plurality of branched optical signals are output from the transfer destination ports 11-2 on the path to the communication destination, respectively. With such a configuration, it is possible to multicast to the destination while reducing the number of ports.

According to the optical GW200b configured as described above, in order to perform multicast, the return route as described in the basic configuration and the first embodiment is not used. Therefore, it is possible to reduce the number of ports used for the return route. For example, in the second embodiment, the number of routes inside the optical SW210b is further reduced by one route, that is, by one port each of ports 11-1-p and 11-2-q, as compared with the first embodiment. .. Therefore, it is possible to transmit an optical signal according to the transfer destination on the path to the communication destination while reducing the number of ports used in the optical SW210b.

In the second embodiment, the power splitter is mainly used, but in the case of multicast demultiplexing for each wavelength (effectively, unicast demultiplexed by wavelength), a demultiplexer may be used.

(Third embodiment)
In the second embodiment, the number of ports can be reduced, but when connecting the subscriber device 40a, it is necessary to select whether to connect to a power splitter or a port to which the power splitter is not connected. As described above, in the second embodiment, when the communication source starts or stops multicast, the port to be connected is changed. In the third embodiment, a configuration for suppressing the port change will be described. In these configurations, the above-mentioned optical SW is replaced with a set of cascade-connected optical SWs.

FIG. 63 is a diagram showing a configuration example of the optical GW 200c in the optical access system of the third embodiment. In FIG. 63, for the sake of simplification of the explanation, the optical SW having the configuration of (11-1-P) × (11-2-Q) is described as a symmetric SW of S × S or the like (S is an integer of 1 or more). , (11-1-P) × (11-2-Q) Asymmetric optical SW such as SW can be easily expanded.
The optical GW 200c shown in FIG. 63 has a first optical switch 210c-1, a second optical switch 210c-2, and power splitters 450-1 to 450-M. The first optical switch 210c-1 and the second optical switch 210c-2 are cascade-connected. In the cascade configuration of the optical GW 200c in the third embodiment, the first optical switch 210c-1 of S × S and the ((ST) + T × k) × ((ST) + T × k) first. The optical switch 210c-2 of 2 is used. Here, S is the number of subscriber devices 40a, T is the number of ports to be branched, and k is the number of branches for each port. The number of ports to be branched is the number of ports to which the power splitter is connected.

If the number of branches k is different for each port, T × k is replaced with the total number of branches of the port. The output of the branching T port in the S × S optical SW210c-1 is passed through the power splitters 450-1 to 450-M, and the output of the remaining (ST) ports is used as it is ((ST). ) + T × k) × ((ST) + T × k) Connect to the port of the optical SW210c-2.

The effect obtained in the third embodiment will be described.
The SW size of the two optical SWs shown in FIG. 63 is 1st stage: S2, 2nd stage: ((ST) + T × k) ² = (S + T × (k- ^{1)) 2} ^. Therefore, the maximum size (S + T × k) ² is reduced to (S + T × (k-1)) ² , and the total number of SW fabrics is (S + T × k) ² -{(S) ² + [(S + T × (k-1)). -1)) ² ] = S (2S-2k + 1) -S ² does not decrease.

Although all ports were supposed to be connected, there may be empty ports or ports to connect to the electrical processing unit. Here, a configuration in the case of connecting an electric processing unit or the like in the third embodiment will be described. In the optical GW 200c, when passing through before multicast or without multicast, the electrical processing unit is connected by an optical SW (for example, optical switch 210c-1) near the subscriber device 40a, and when passing through after multicast, respectively. The electric processing unit is connected by other optical SW (for example, optical switch 210c-2). It should be noted that passing before multicast is suitable for batch processing of FEC (forward error correction), encryption, etc., and passing after multicast changes FEC, encryption, etc. for each destination. Suitable for cases.

In the third embodiment, two-way communication is also possible. The optical signal in the downlink direction is routed in the reverse direction to the uplink direction. In this case, the power splitter 450 is used as a turnout. The power splitter 450 used here has an H × I input / output port. When H = 1 and I = 2, the power splitter 450 branches the optical signal going up, for example, and multiplexes the optical signal going down. In the example of FIG. 63, the power splitter 450 branches the input optical signal and inputs it to a plurality of ports of the optical SW210c-2, and multiplexes the optical signals output from each of the plurality of ports of the optical SW210c-2. The light is output to port 11-2 (for example, port 11-2- (Q-1)) of the optical SW210c-1.

(Fourth Embodiment)
FIG. 64 is a diagram showing a configuration example of the optical GW200d in the optical access system of the third embodiment. In FIG. 64, the optical SW having the configuration of (11-1-P) × (11-2-Q) is described as a symmetric SW such as S × S for the sake of simplification of the explanation, but (11-1-P). It can be easily expanded even in the case of an asymmetric optical SW such as a SW having a × (11-2-Q) configuration.

The optical GW 200d shown in FIG. 64 has a first optical switch 210c-1, a second optical switch 210d-2, and power splitters 450-1 to 450-M. The difference between the optical GW 200d and the optical GW 200c is that a second optical switch 210d-2 is provided in place of the second optical switch 210c-2. In the cascade configuration of the optical GW200d in the fourth embodiment, an S × S optical SW and a (T × k) × (T × k) optical SW are used.

If the number of branches k is different for each port, T × k is replaced with the total number of branches of the port. The output of the branching T port in the S × S optical SW210c-1 is connected to the second optical switch 210d-2 via the power splitters 450-1 to 450-M. The output of the remaining (ST) ports does not pass through the second optical switch 210d-2.

The effect obtained in the fourth embodiment will be described.
The SW sizes of the two optical SWs shown in FIG. 64 are 1st stage: S2 and ^2nd stage: (T × k) ² . Therefore, the maximum size (S + T × k) ² is reduced to MAX (S ² , (T × k) ² ), and the total number of SW fabrics is (S + T × k) ² -{(S) ² + (T × k). ) ² } = 2STk decrease.

Although all ports were supposed to be connected, there may be empty ports or ports to connect to the electrical processing unit. Here, a configuration in the case of connecting an electric processing unit or the like in the fourth embodiment will be described. In the optical GW200d, an electric processing unit is connected to the optical SW (for example, an optical switch 210c-1) near the subscriber device 40a, and other optical SWs (for example, an optical switch) are used when passing through each after multicast. Connect the electric processing unit at 210d-2). It should be noted that passing before multicast is suitable for batch processing of FEC (forward error correction), encryption, etc., and passing after multicast changes FEC, encryption, etc. for each destination. Suitable for cases.

In the fourth embodiment, two-way communication is also possible. The optical signal in the downlink direction is routed in the reverse direction to the uplink direction. In this case, the power splitter 450 is used as a turnout. The power splitter 450 used here has an H × I input / output port. When H = 1 and I = 2, the power splitter 450 branches the optical signal going up, for example, and multiplexes the optical signal going down. In the example of FIG. 64, the power splitter 450 branches the input optical signal and inputs it to a plurality of ports of the optical SW210d-2, and multiplexes the optical signals output from each of the plurality of ports of the optical SW210d-2. The light is output to port 11-2 (for example, port 11-2- (Q-1)) of the optical SW210c-1.

(Fifth Embodiment)
In the basic configuration, as shown in FIGS. 3 to 5, a configuration is described in which the return transmission line is not provided with a power splitter or a WDM device, and the ports are directly connected to return the optical signal. In the fifth embodiment, variations of the configuration of the folding back of the optical signal will be described. For example, the folded transmission line may be configured by a network that is folded back via a network such as an optical SW in an intermediate layer such as a Folded Clos network. A part of the port of the input / output SW of a part of the Folded Clos network to the intermediate layer SW and a part of the port of the intermediate layer SW to the 11-2-Q side, and a part of the input / output SW to the intermediate layer SW. The return transmission line may be configured so that a part of the port or a part of the intermediate layer SW is on the 11-2-Q side. As a result, the optical SW enables return communication.

FIG. 65 is a diagram showing a configuration example of the optical GW200e in the optical access system of the fifth embodiment. In FIG. 65, three configurations (first configuration to third configuration) will be described as variations of the configuration for folding back the optical signal.

(First configuration of optical signal folding)
In the first configuration of optical signal folding, the optical GW200e has an optical SW210e-1 and a WDM device 80-1. Subscriber devices 40a-1 to 40a-2 are connected to ports 11-1-1 to 11-1-2 of the optical GW 200e by transmission lines 50-1-1 to 50-1-2. The WDM device 80-1 is connected to the ports 11-2-1 to 11-2-2 of the optical GW200e. The subscriber devices 40a-1 to 40a-2 transmit and receive optical signals having different wavelengths. The WDM device 80-1 combines the optical signals output from the ports 11-2-1 and 11-2-2 and outputs them to the folded transmission line 51a-1. The return transmission line 51a-1 is connected to the port 11-2-3. With such a configuration, the optical signal can be folded back.

(Second configuration of optical signal folding)
In the second configuration of optical signal folding, the optical GW200e has an optical SW210e-1, a plurality of WDM devices 80-2 to 80-3, and a plurality of monitoring units 60-1 and 60-2. Subscriber devices 40ap to 40a- (p + 1) are connected to ports 11-1-p to 11-1- (p + 1) of the optical GW200e via transmission lines 50-1-p to 50-1- (p + 1). Has been done. The WDM device 80-2 is connected to the ports 11-2-q to 11-2- (q + 1) of the optical GW200e.

The subscriber devices 40a-p to 40a- (p + 1) transmit and receive optical signals having different wavelengths. The WDM device 80-2 combines the optical signals output from the ports 11-2-1 and 11-2-2 and outputs them to the folded transmission line 51a-2. The folded transmission line 51a-2 is connected to the WDM device 80-3. The WDM device 80-3 demultiplexes the input optical signal and outputs the demultiplexed optical signal to the monitoring units 60-1 and 60-2, respectively. The monitoring units 60-1 and 60-2 monitor the optical signal transmitted through the transmission line. With such a configuration, the optical signal can be folded back.

(Third configuration of optical signal folding)
In the third configuration of folding back the optical signal, the optical GW200e has an optical SW210e-1 and an optical SW210e-2. The subscriber device 40a-P is connected to the port 11-1- (P-1) of the optical GW 200e by a transmission line 50-1-P. The optical SW210e-2 is connected to the port 11-2- (Q-1) of the optical GW200e. The subscriber device 40a-P transmits and receives optical signals. The optical SW210e-1 outputs an optical signal input from the port 11-1- (P-1) from the port 11-2- (Q-1). The optical signal output from port 11-2- (Q-1) is output to the optical SW210e-2. The optical SW210e-2 outputs the input optical signal to the port 11-2-Q. With such a configuration, the optical signal can be folded back.

According to the optical GW200e configured as described above, it is possible to apply a return communication configuration other than the configuration shown in the basic configuration. As a result, the degree of freedom of combination is improved, and it becomes possible to improve the convenience.

Next, a configuration for reducing the port use of the optical SW accommodating the subscriber device 40 will be presented. Although the optical SW1010 shown in FIGS. 27 and 28 will be described here as an example, the same can be applied to other optical SWs (for example, optical SW10, optical SW210, etc.) shown in the above description.
In the configuration shown in FIGS. 27 and 28, as a transmission line, for example, when viewed from the subscriber device 40 on the port 11-1 side (ONU in FIGS. 27 and 28), it is clearly connected to the port 11-2. This corresponds to an increase in the number of connections on the output route. Therefore, as described above, the optical SW1010 is connected to the subscriber device 40 on the port 11-1 side of another optical SW1010 (for example, the optical SW1010-2 to 1010-4), and the optical SW1010 is a full mesh as shown in FIG. 27. When connected to the mold, port 11-1 of optical SW1010-1 (for example, port 11-1-1 (connected to ONU # 11)) and port 11-2 (for example, port 11-2-q1 (* a connection)) )), Port 11-1 and port 11-2 (for example, port 11-1-p1 (* a connection)) of the optical SW1010-2 to which the opposing subscriber device 40 is connected on the port 11-1 side. Port 11-2-x (connected to the return transmission line), port 11-2 and port 11-2 (for example, port 11-2-y, port 11-2-z) connected to the return transmission line, and the opposite ONU. It occupies 6 ports with the port 11-1 to be connected (for example, port 11-1-1 (connected to ONU # 21)). The same applies when the return transmission line is installed in the optical SW1001.

When connected in a ring shape as shown in FIG. 28, port 11-1 and port 11-2 of the optical SW1010-1 (for example, port 11-1-1 (connected to ONU # 11), port 11-2- q1 (connection of * a)), port 11-1 and port 11-2 of optical SW1010-2 via (for example, port 11-1-p1 (connection of * a)), port 11-2-q1 (* d) (Connection), port 11-1 and port 11-2 (for example, port 11-1-p1 (* d connection)) of the optical SW1010-3 to which the opposing subscriber device 40 is connected on the port 11-1 side. Port 11-2-x (connected to the return transmission line), port 11-2 and port 11-2 (for example, port 11-2-y, port 11-2-z) connected to the return transmission line, and the opposite ONU. It occupies 8 ports with the port 11-1 to be connected (for example, port 11-1-1 (connected to ONU # 21)). The same applies when the return transmission line is installed in the optical SW1010-1 or the optical SW1010-2. Is.

Based on the above points, a configuration for reducing the use of the optical SW port for accommodating the subscriber device 40 will be described with reference to FIG. FIG. 66 shows four configurations as configurations for reducing the use of the optical SW port.

(First configuration)
As shown in FIG. 66 (A), in the first configuration, the optical SW1010-1 to the optical SW1010-3 and the optical SW1200 are shown. In the first configuration, the transmission line across the optical SW is set to the optical SW1200 from the viewpoint of improving the degree of freedom of connection for changing the ratio of the ports of the optical SW passed through the transmission line across the optical SW. The configuration of the optical SW1200 is basically the same as that of the other optical SW1010. If the transmission line across the optical SW is an optical SW, the use of the optical SW port accommodating the subscriber device 40 can be reduced.

A means for reducing the use of the optical SW port for accommodating the subscriber device 40 will be described. In FIG. 27, the transmission lines connected to the optical SW1010-1 to 1010-4 are shown in one set, but the ONU of the same optical SW occupies the transmission line from a single optical SW1010. Connect with. For example, in the example of FIG. 27, when connecting from ONU # 11, ONU # 12, and ONU # 13 to ONU # 21, ONU # 22, and ONU # 23, for example, 6 ports and 8 ports are connected via another optical SW. , Occupies 22 ports of 8 ports. On the other hand, assuming that the transmission path across the optical SW is the optical SW1200 as shown in FIG. 66A, 18 ports are sufficient as the ports of the optical SW1010-1 and the optical SW1010-2 accommodating the subscriber device 40. Optical SW1010-1 to 1010-4 are one aspect of a plurality of optical switches. In this description, the optical SW1010-1 will be described as one aspect of the first optical switch among the plurality of optical switches, and the optical SW1010-2 will be described as one aspect of the second optical switch among the plurality of optical switches. do.

More specifically, the optical SW1200 is connected to the ports 11-1 and 11-2 of the optical SW1010-1, and further, the ports 11-1 and 11-2 of the optical SW1010-2 and the optical SW1010-3. It is connected to port 11-1 and port 11-2 of. As described above, the optical SW1200 is the first port (for example, port 11-1) of the plurality of optical switches and the side different from the first port (for example, the side where the port 11-1 is provided in the plurality of optical switches). It is connected to the second port (for example, port 11-2) on the side different from the above. The first port and the second port shown here are examples, and port 11-1 may be the second port and port 11-2 may be the first port. The same applies to the following description. Then, the optical SW1200 connects the port 11-2 on the output side of the plurality of optical SW1010s and the port 11-1 on the input side of the plurality of optical SW1010s. For example, the optical SW1200 connects the port 11-2 on the output side of the optical SW1010-1 and the port 11-1 on the input side of the optical SW1010-2. The optical SW control unit 320 controls the optical SW 1200 so that the path inside the optical SW 1200 becomes a path toward the transfer destination on the route to the communication destination. With this configuration, the number of ports that pass through the other optical SW1010-2 and 1010-3 can be reduced as shown in FIG. 27.

(Second configuration)
As shown in FIG. 66 (B), in the second configuration, optical SW1010-1 to optical SW1010-3 are shown. In the second configuration, the folded transmission line is not connected to the same optical SW, but is connected between the optical SWs connected by the respective subscribers facing each other. For example, port 11-1-1 connecting optical SW1010-1 and ONU # 11, port 11-2-x of optical SW1010-1, folded transmission line, port 11-2-y of optical SW1010-2, optical SW1010. Connect -2 and ONU # 21 as in port 11-1-1. That is, in the second embodiment, the ports 11-2 on the same side of the different optical SW1010 are connected by a folded transmission line. In the example shown in FIG. 66B, the port 11-2 of the optical SW1010-1 and the port 11-2 of the optical SW1010-2 are connected by a folded transmission line, and the port 11-2 of the optical SW1010-2 and the optical SW1010 are connected. The port 11-2 of -3 is connected by a folded transmission line, and the port 11-2 of the optical SW1010-1 and the port 11-2 of the optical SW1010-3 are connected by a folded transmission line. In this case, since 4 ports are used, it can be seen that the use of 2 ports can be reduced as compared with the use of 6 ports.

(Third configuration)
As shown in FIG. 66 (C), in the third configuration, the optical SW1010-1 to the optical SW1010-3 and the optical SW1200 are shown. In the third configuration, the optical SW1200 is used as the return transmission line. When the optical SW1200 is a SW such as the (11-1-P) × (11-2-Q) configuration, light is emitted from a single optical SW (eg, optical SW1010-1) accommodating the subscriber device 40. It is connected to each of port 11-1 and port 11-2 of the optical SW1200 which is a transmission line across the SW, and is connected from port 11-1 to port 11-2 and from port 11-2 to port 11-1. When different optical SWs accommodating the subscriber device 40 are connected to each other, it becomes a transmission line across the optical SW, and when the same optical SW through is connected, it becomes a return transmission line in the same SW. That is, in the third configuration, a part of the port 11-2 on the output side of the optical SW1010-1 to the optical SW1010-3 is connected to the port 11-1 of the optical SW1200, and the optical SW1010-1 to the optical SW1010-3 are connected. The other part of port 11-2 on the output side is connected to port 11-2 of the optical SW1200. As a result, the optical SW1200 connects the ports 11-2 on the output side of the optical SW1010-1 to the optical SW1010-3. The optical SW control unit 320 controls the optical SW1200 so that the path inside the optical SW1200 connects the ports 11-2 on the output side of the optical SW1010-1 to the optical SW1010-3.
The second or third configuration may be combined with the mesh type or ring type optical SW crossing transmission line of FIG. 27 or the first configuration.

(Fourth configuration)
As shown in FIG. 66 (D), in the fourth configuration, the optical SW1010-1 to the optical SW1010-3 and the optical SW1200 are shown. The fourth configuration is an extension of the third configuration. In the third configuration, at least a part of the uplink is installed not on the port 11-2 side but on the port 11-1 side, and when connecting to the uplink, the uplink is connected via the return transmission line. That is, in the fourth configuration, the ports 11-1 of the optical switches 1010-1 to 1010-3 that are not connected to the optical SW1200 are connected to the uplink. This configuration is suitable when folding is the main case. For example, when the subscriber devices 40 are connected to each other in a full mesh or a form close to a full mesh, the number of ports 11-1 is smaller than that of the port 11-2. In such a case, when the optical SW is a symmetric SW of P × P, the port 11-1 side to connect the subscriber is left over, so it is diverted to the uplink side and the port is effectively utilized.

Next, as another aspect (modification example) of the monitoring unit 60 shown in FIGS. 33 to 36, a configuration in which the monitoring unit includes a transmitter will be specifically described with reference to FIGS. 67 to 69. 67 to 69 are block diagrams of another aspect (modification example) of the monitoring unit 60. Although the monitoring unit 60 will be described as an example in FIGS. 67 to 69, the monitoring unit 260 may be used instead of the monitoring unit 60, and the configuration of the monitoring unit 260 may be the configuration shown in FIGS. 67 to 69. .. 67 and 68 show an example in which a transmitter and a receiver are connected to a transmission line on the same side in opposite directions as a configuration in which a signal is transmitted toward an object to be monitored. FIG. 69 shows a configuration in which a transmitter and a receiver are connected in the same direction when merging into a transmission line opposite to the input of the main signal in the same direction as the main signal.

The monitoring unit 75a shown in FIG. 67A has a power splitter 61, a receiver 62, and a transmitter 76. The monitoring unit 75a shown in FIG. 67 (A) differs from the monitoring unit 60a shown in FIG. 33 (A) in that it includes one transmitter 76 and one receiver 62. The transmitter 76 transmits the optical signal input via the power splitter 61 toward the object to be monitored (for example, the control unit 20 or the OPS300). As shown in FIG. 67 (A), the transmitter 76 and the receiver 62 are connected to the transmission lines on the same side in opposite directions.

The monitoring unit 75b shown in FIG. 67B includes a power splitter 61, a plurality of receivers 62-1 to 62-3, a plurality of WDM devices 63b-1 to 63b-2, and a plurality of transmitters 76-1. It has ~ 76-3. The difference between the monitoring unit 75b shown in FIG. 67 (B) and the monitoring unit 60b shown in FIG. 33 (B) is that the three receivers 62- instead of the six receivers 62-1 to 62-6. The point is that 1 to 62-3 and three transmitters 76-1 to 76-3 are provided. Transmitters 76-1 to 76-3 are connected to the WDM device 63b-1. Receivers 62-1 to 62-3 are connected to the WDM device 63b-2. The WDM device 63b-1 splits the optical signal branched by the power splitter 61 and outputs the branched optical signals to the transmitters 76-1 to 76-3. As shown in FIG. 67 (B), the transmitters 76-1 to 76-3 and the receivers 62-1 to 62-3 are connected to the transmission lines on the same side in opposite directions.

The monitoring unit 75c shown in FIG. 67C has a power splitter 61, a receiver 62, a WDM device 63c, and a transmitter 76. The difference between the monitoring unit 75c shown in FIG. 67 (C) and the monitoring unit 60c shown in FIG. 33 (C) is that the receiver 62 and the transmitter are replaced with the two receivers 62-1 to 62-2. It is a point to have 76.

The monitoring unit 75d shown in FIG. 68 (A) includes a plurality of power splitters 61-1 to 61-3, a plurality of receivers 62-1 to 62-3, a WDM device 63d, and a plurality of transmitters 76-1. It has ~ 76-3. The difference between the monitoring unit 75d shown in FIG. 68 (A) and the monitoring unit 60d shown in FIG. 34 (A) is that the three receivers 62- instead of the six receivers 62-1 to 62-6. The point is that 1 to 62-3 and three transmitters 76-1 to 76-3 are provided. A power splitter 61-1 is provided on the transmission line 606-1, and a receiver 62-1 and a transmitter 76-1 are connected to the power splitter 61-1. A power splitter 61-2 is provided on the transmission line 606-2, and a receiver 62-2 and a transmitter 76-2 are connected to the power splitter 61-2. A power splitter 61-3 is provided on the transmission line 606-3, and a receiver 62-3 and a transmitter 76-3 are connected to the power splitter 61-3.

The monitoring unit 75e shown in FIG. 68B has a plurality of power splitters 61-1 to 61-2, a receiver 62, a plurality of WDM devices 63e-1 to 63e-2, and a transmitter 76. The difference between the monitoring unit 75e shown in FIG. 68 (B) and the monitoring unit 60e shown in FIG. 34 (B) is that the receiver 62 and the transmitter are replaced with the two receivers 62-1 to 62-2. It is a point to have 76. A power splitter 61-1 is provided on the transmission line 602-1, and a transmitter 76 is connected to the power splitter 61-1. A power splitter 61-2 is provided on the transmission line 602-2, and a receiver 62 is connected to the power splitter 61-2.

The monitoring unit 77a shown in FIG. 69A has a power splitter 61, a receiver 62, and a transmitter 76. The monitoring unit 77a shown in FIG. 69A differs from the monitoring unit 60a shown in FIG. 33A in that the receiver 62 and the transmitter are replaced with the two receivers 62-1 to 62-2. It is a point to have 76. As shown in FIG. 69 (A), the transmitter 76 and the receiver 62 are connected to a transmission line on the same side in the same direction.

The monitoring unit 77b shown in FIG. 69B includes a power splitter 61, a plurality of receivers 62-1 to 62-4, a plurality of WDM devices 63b-1 to 63b-2, and a plurality of transmitters 76-1. It has ~ 76-4 and a plurality of power splitters 78-1 to 78-4. The monitoring unit 77b shown in FIG. 69 (B) differs from the monitoring unit 60b shown in FIG. 33 (B) in that the four receivers 62- instead of the six receivers 62-1 to 62-6. It is provided with 1 to 62-4, four transmitters 76-1 to 76-4, and four power splitters 78-1 to 78-4. Power splitters 78-1 and 78-2 are connected to the WDM device 63b-1, and power splitters 78-3 and 78-4 are connected to the WDM device 63b-2. The transmitter 76-1 and the receiver 62-1 are connected to the power splitter 78-1, the transmitter 76-2 and the receiver 62-2 are connected to the power splitter 78-2, and the power splitter 78-3 is connected. Is connected to the transmitter 76-3 and the receiver 62-3, and the transmitter 76-4 and the receiver 62-4 are connected to the power splitter 78-4. As shown in FIG. 67 (B), the transmitters 76-1 to 76-4 and the receivers 62-1 to 62-4 are transmission lines on the same side in the same direction in the pair of the transmitter 76 and the receiver 62. Is connected to. In FIG. 69B, the transmitters 76-2 and 76-4 are provided outside the monitoring unit 77b, but may be provided inside the monitoring unit 77b.

The monitoring unit 77c shown in FIG. 69C has a power splitter 61, a plurality of receivers 62-1 to 62-2, a WDM device 63c, and a plurality of transmitters 76-1 to 76-2. The monitoring unit 77c shown in FIG. 69C differs from the monitoring unit 60c shown in FIG. 33C in that two transmitters 76-1 to 76-2 are newly provided. The monitoring unit 77c shown in FIG. 69 (C) has a different connection relationship from the receivers 62-1 to 62-2 of the monitoring unit 60c shown in FIG. 33 (C). Specifically, in the monitoring unit 77c, the receivers 62-1 to 62-2 and the transmitters 76-1 to 76-2 are connected to the power splitter 61, and the receivers 62-1 and the transmitters 76-1 are connected. Is connected to the transmission line on the same side, and the receiver 62-2 and the transmitter 76-2 are connected to the transmission line on the same side.
The number of the power splitter 61, the receiver 62, the WDM device 63, and the transmitter 76 shown in FIGS. 67 to 69 is an example and may be changed depending on the situation.

The superimposition of the AMCC signal on the main signal will be explained. Since they are superimposed, the main signal and the AMCC signal are carried by optical signals of the same wavelength. The main signal is a signal such as CPRI (Common Public Radio Interface) such as an OK (On-off keying) signal of 10 Gbit / s (Gigabit per second). The AMCC signal does not overlap with the main signal of electricity, for example, and is superimposed on the main signal with a carrier wave having a carrier frequency such as 1 MHz or 500 kHz. The modulation method is intensity modulation, phase modulation, or the like. For superimposition, for example, a power combiner synthesizes a main signal of electricity of 10 GHz and an AMCC signal of electricity of 1 MHz, and the combined signal is modulated to generate a main signal on which the AMCC signal is superimposed. The superimposed AMCC signal can be separated from the main signal.

In the electrical region, the AMCC signal and the main signal use different frequencies. The AMCC signal has a narrower band than the main signal. For example, OITDA standard TP20 optical transmission active component-performance standard-GPON optical transceiver (Reference 1: http://www.oitda.or.jp/main/st/TP20-1.pdf) and ITU-TG. As shown in .958 Appendix I, if the standard of continuous bearing capacity of the same code is 72 bits, the lower limit of GE-PON of 1.25 Gbit / s is sufficiently lower than about 20 MHz, for example, half of it or 1.25 GHz. High enough, for example twice that, or well below the lower limit of 720 kHz for STM-0 at 51.84 Mbit / s for slow signals, for example half that or well above 51.84 MHz, for example twice that. good.
As the carrier frequency, another frequency that does not overlap with the main signal of electricity such as 500 kHz may be used, and another modulation method such as phase modulation may be used as the modulation method.

When the subscriber device 40 and the control unit 20 have a single-core bidirectional transmitter / receiver, the power splitter used in each of the above embodiments goes through the same path of the optical SW210 while remaining in the single-core bidirectional manner. It may be connected by means of two cores, or it may be separated into two cores and connected via each route. When the subscriber device 40 and the control unit 20 have a two-core bidirectional transmitter / receiver, they may be bundled in a single-core bidirectional manner and then connected via the same path of the optical SW210, or the two-core remains. You may connect via each route. When one of the subscriber device 40 and the control unit 20 has a single-core bidirectional transmitter and the other has a bidirectional transmitter / receiver, the two-core bidirectionality is bundled into one core and connected via the same path of the optical SW210. Alternatively, one core bidirectional may be separated into two cores and connected via their respective routes.

The power splitter used in both the upper and lower directions is suitable when the usable wavelength bands do not overlap in the up direction and the down direction, for example, the 1.3 micron band and the 1.55 micron band. When at least one of them sends and receives an optical signal with a single-core bidirectional optical transmitter / receiver, it may be connected by one set of ports of the optical SW, or it may be connected by two sets of ports and a duplexer (for example, a duplexer). It may be multiplexed in the opposite direction with a WDM device or a WDM filter) or a power splitter. For each transmission / reception, different sets of ports may be connected to connect one optical transmitter to the other optical receiver and the other optical transmitter to one optical receiver. This is suitable when a two-core optical transmitter / receiver is used. In this case, different routes can be used on the transmitting side and the receiving side.

You may connect to the sender in multiple sets or to the receiver in multiple sets. In this case, it is possible to connect and control a plurality of devices or functional units. Multiple separation of connections and controls can use source or destination ports, wavelengths and devices or functional parts, such as identifiers that identify subscriber devices, such as MAC addresses.

The optical SW, the port, the transmission line, or their connection point may be provided with a power splitter or a duplexer between the optical SW and the transmission line connected to another ground, the optical SW, or an upper network. The combined duplexer combines optical signals of different wavelengths output from each of different subscriber devices, etc. from multiple ports of the optical SW, and outputs them to another ground, an optical SW, or a transmission line connected to an upper network. .. The combined demultiplexer demultiplexes the optical signal transmitted from any other ground, optical SW, or higher network according to the wavelength, and inputs the optical signal to the optical SW from the port corresponding to the wavelength. In each of the above embodiments, the duplexer and the power splitter have been described, but if the duplexer does not combine and split depending on the wavelength, the duplexer may be a power splitter, and depending on the wavelength, only the combine and the demultiplexer, In the case of only merging multiplex regardless of wavelength and only branching regardless of wavelength, it may be a combiner, a demultiplexer, a merging device, and a branching device, respectively.

The power splitter is suitable when the uplink and downlink signals are multiplexed by, for example, time division multiplexing other than wavelength division multiplexing, and when the wavelength bands used by the uplink and downlink signals overlap at least partially. In the latter case, the filter may be filtered between the optical receiver, the transmission line before it, between the power splitter and the transmission line, etc., and when passing through multiple sections, when multiplexing with other signals, another signal may be used. It is desirable to filter before multiplexing so as not to affect the signal. If the wavelength to be filtered can be changed by the combined duplexer or the combination of the power splitter and the filter, the subscriber device may change the wavelength according to the wavelength transmitted and received, or the control unit may change the wavelength.

In the above, the wavelength change process performed by the subscriber device 40 requesting the wavelength change has been described, but the same applies to the wavelength change process performed by the control unit 20 based on the monitoring information or the like.
The control signal is exchanged between the control unit 20 and the subscriber device 40. For example, the subscriber device 40 transmits a connection request to the control unit 20, and the control unit 20 transmits a control signal to the subscriber device 40. For example, the control unit 20 allocates a wavelength used for communication by the subscriber device 40.

The control signal may be monitored by the monitoring unit 60 and may be exchanged between the monitoring unit 60 and the subscriber device 40, or between the monitoring unit 60 and the control unit 20.
The wavelength control unit 310 and the optical SW control unit 320 may be mounted using one information processing device, or may be mounted using a plurality of information processing devices communicably connected via a network. good.
As shown in FIG. 70, the optical GW includes an OPS300 or a control unit 20, an optical SW, a monitoring unit, an electric processing unit, a folded transmission line, a power splitter (power splitter), and a demultiplexer (WDM device, WDM filter). It may be configured as a device (optical communication device of the present invention) including any or all of the above.

In each of the above embodiments, the assignment of wavelengths to the subscriber device 40 has been described as an example, but wavelength, time, polarizations orthogonal to each other, modes orthogonal to each other, codes orthogonal to each other, frequencies, cores, core wires or them. Even if the configuration is such that the wavelength, etc., which is a combination of the above, is assigned. For example, when the allocation is time, polarization, mode, sign, core, and core wire, the duplexer is a combination of a turnout and a delay line, a polarization mode coupler, a mode coupler, a decoding device, and a core. The same applies if the switch is replaced with a turnout, a turnout between core wires, or the like.

The

control units

20, 230, 235, the

monitoring unit

260, 265, 267, the wavelength control unit 310, and the optical SW control unit 320 described above include a CPU, a memory, an auxiliary storage device, and the like connected by a bus, and execute a program. By doing so, some or all of the above-mentioned functions may be realized. Note that some or all of the functions of the

control units

20, 230, 235, the

monitoring unit

260, 265, 267,267, the wavelength control unit 310, and the optical SW control unit 320 use hardware such as ASIC, PLD, and FPGA. It may be realized. The programs of the

control units

20, 230, 235, the

monitoring unit

260, 265, 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 portable medium such as a magneto-optical disk, ROM, or CD-ROM, or a storage device such as a hard disk built in a computer system. The program may be transmitted over a telecommunication line.

As described above, the embodiment of the present invention has been described in detail with reference to the drawings, but the specific configuration is not limited to this embodiment, and the design and the like within a range not deviating from the gist of the present invention are also included.

The present invention can be applied to an optical access system technique using an optical switch.

1 ... Optical communication system,
10, 10a, 10b, 10c, 10d, 10e, 10f, 10g, 34, 95a-1, 95a-2, 95b-1, 95b-2, 96a-1, 96a-2, 96b-1, 96b-2, 210, 210a-1 to 210a-2, 210b, 210c-1 to 210c-2, 210d-2, 210e-1 to 210e-2, 211, 212a, 212b, 212c, 1001, 1002, 1003, 1004, 1005, 1006, 1007, 1008, 1009a, 1009b, 1010-1 to 1010-4 ... 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, 262 ... Optical receiver,
25 ... Wavelength control unit,
26, 320 ... Optical SW control unit,
30 ... Optical communication network,
31 ... WDM access ring network,
32-1 to 32-r ... Add / Drop node,
33 ... Demultiplexing part,
35 ... Combined wave part,
40, 40-1 to 40-M, 40a-1 to 40a-3, 40b-1 to 40b-3, 40c-1 to 40c-3, 40a-1-1, 40a-1-2, 40-p- 1-40-p-Np, 40-p-N, 40-p-40- (p + N) ... Subscriber device,
46-1, 46-3 ... User,
46-2 ... Mobile base station,
50, 50-1, 50-2, 50-1-p to 50-1- (p + N), 50-1-p1 to 50-1-pN, 50-1-p-1 to 50-p-Np, 50-2-1 to 50-2-q, 50-2- (N-1), 50-2-N, 50-2-q-1 to 50-2-q-N, 50-2- (1 + N) ), 53, 54a, 54b, 54c, 54d, 92, 93-1 to 93-N, 501, 503, 504, 511, 512, 521, 522, 513, 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,
51, 73 ... Return transmission line,
55, 55-1, 55-2, 55-p, 55- (p + 1), 56, 57a, 57b, 61, 66, 69, 71, 72, 251, 251a, 251b, 252, 252b, 254, 258, 259, 270, 271, 272, 273, 502, 507 ... Power Splitter,
58, 59 ... Distributor,
60, 60a-60h, 65 ... Monitoring unit,
67, 68, 80, 80a, 80b, 80c, 81, 89, 97 ... WDM device,
82a-1 to 82a-n, 82b-1 to 82b-m, 241 and 247, 458 ... Combiner,
83a-1 to 83a-n, 83b-1 to 83bm, 242, 248, 457 ... Demultiplexer,
85, 610 ... O / E conversion unit,
86, 620 ... Processing execution unit,
87, 630 ... E / O converter,
88 ... Memory,
90, 91 ... Multiplex communication transmission line,
100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117 ... Optical access system,
200, 200a-200e, 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, 235 ... Control unit,
231 and 261 ... Wavelength demultiplexer,
233, 269 ... Tunable transmitter,
250, 250a, 250b, 253, 255 ... Branch,
260, 265 ... Monitoring unit,
266 ... Tunable optical receiver,
267 ... Monitoring Department,
268 ... Tunable wavelength receiver,
300 ... Operation system,
301 ... Control unit,
310 ... Wavelength control unit,
350 ... Management database,
452 ... Tunable wavelength receiver,
453 ... Tunable wavelength filter,
459, 459a-459e ... WDM filter,
84, 600 ... Electrical processing unit,
861 ... Processor,
862 ... Accelerator

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 another transmission line.
A combined turnout that branches the input optical signal to a plurality of ports of the optical switch and outputs or multiplexes the output.
At least the optical signal output from the junction branching device to the plurality of ports is output to another plurality of ports to which the transmission path corresponding to the transfer destination on the path to the communication destination is connected, or the junction branching device. With an optical switch control unit that controls the optical switch so that optical signals input from the plurality of ports are input from other plurality of ports to which a transmission path corresponding to a path from a communication source device is connected. ,
An optical communication device equipped with.
The junction branching device is provided with another optical switch provided on the first port side of the optical switch and connected to the second port of the optical switch or a second port on a side different from the first port of the optical switch. , Connected by a transmission line without going through the optical switch,
The optical switch control unit further sets the optical switch so as to output an optical signal input from any one of the plurality of first ports of the optical switch to the second port of the optical switch. Control and
The joint branching device inputs an optical signal output from the second port of the optical switch or the other optical switch via the transmission path, and the input optical signal is used as the first optical signal of the optical switch. The optical communication device according to claim 1, wherein the optical communication device outputs to a plurality of first ports different from the ports directly or via another junction / branching device.
A first optical switch that is connected to a plurality of transmission lines and outputs an optical signal input from one of the transmission lines to another transmission line.
A second optical switch cascaded to the first optical switch,
The optical signal output from a part of the ports of the first optical switch is branched into a plurality of ports of the second optical switch and output, or is output from a plurality of ports of the second optical switch. A branching device that multiplexes the optical signal and outputs it to the first optical switch,
An optical switch control unit that controls the first optical switch and the second optical switch so that the optical signal transmitted from the subscriber device is output to a transmission path corresponding to the transfer destination on the path to the communication destination. When,
An optical communication device equipped with.
The remaining second port excluding a part of the second port among the plurality of second ports of the first optical switch is directly connected to the first port of the second optical switch.
The optical signal output from the remaining second port of the first optical switch is input to the first port of the second optical switch.
The light according to claim 3, wherein the optical signal output from the second port of the part of the first optical switch is input to the first port of the second optical switch via the junction switch. Communication device.
The optical signal output from the remaining second port excluding some of the second ports among the plurality of second ports of the first optical switch is output without going through the second optical switch.
The optical communication according to claim 3, wherein the optical signal output from the second port of the part of the first optical switch is input to the first port of the second optical switch via the branching device. Device.
A first optical switch that is connected to a plurality of transmission lines and outputs an optical signal input from one of the transmission lines to another transmission line.
A second optical switch connected to the second port of the first optical switch,
Equipped with
The second optical switch is an optical communication device that inputs an optical signal output from the second port and outputs the input optical signal to another second port of the first optical switch.
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 another transmission line.
An optical signal transmitted from each of the plurality of subscriber devices is input via the optical switch, the input optical signal is converted into an electric signal and multiplexed, and the multiplexed electric signal is modulated to have a plurality of wavelengths. The electric signal converted into the optical signal of 1 or more and input to the optical switch, or the multiplexed electric signal or the multiplexed electric signal is converted into one or more optical signals of one or more wavelengths and input to the optical switch. Processing unit and
The plurality of optical signals input to the optical switch are output to the electric processing unit according to the combination of the plurality of subscriber devices that have transmitted the input plurality of optical signals and the wavelength of the input optical signals. An optical switch control unit that controls the optical switch so that a signal input from the electric processing unit is output to the transmission path according to the transfer destination on the path to the communication destination.
An optical communication device equipped with.
A plurality of optical switches connected to a plurality of transmission lines and outputting an optical signal input from one of the transmission lines to another transmission line, and a plurality of optical switches.
Other optical switches different from the plurality of optical switches connected to the first port of the plurality of optical switches and the second port on the side different from the first port, and
Equipped with
The other optical switch is an optical communication device that connects the second port of the first optical switch among the plurality of optical switches and the first port of the second optical switch among the plurality of optical switches. ..
A plurality of optical switches that are connected to a plurality of transmission lines and output an optical signal input from one of the transmission lines to another transmission line.
Equipped with
An optical communication device that connects ports on the same side of different optical switches with a folded transmission line.
A plurality of optical switches connected to a plurality of transmission lines and outputting an optical signal input from one of the transmission lines to another transmission line, and a plurality of optical switches.
A part of the second port of the plurality of optical switches is connected to the first port, the other part of the second port of the plurality of optical switches is connected to the second port, and the second of the plurality of optical switches is connected. With other optical switches that connect ports to each other,
An optical communication device equipped with.
The optical communication device according to claim 10, wherein the ports of the plurality of optical switches on the side not connected to the other optical switches are connected to the uplink.
Further, a monitoring unit for monitoring an optical signal transmitted through the transmission line is provided.
The monitoring unit has a plurality of receivers, a plurality of switches for branching an optical signal transmitted through the transmission line, and a combiner / demultiplexer for combining or demultiplexing an input optical signal.
A turnout is provided in each of the plurality of transmission lines through which the optical signal demultiplexed by the combine demultiplexer is transmitted.
The optical communication device according to any one of claims 1 to 11, wherein the receiver receives an optical signal branched by the turnout.
Further, a monitoring unit for monitoring an optical signal transmitted through the transmission line is provided.
The monitoring unit includes one or more receivers, a branching device that branches an optical signal transmitted through the transmission line, and a modulator that modulates the optical signal transmitted through the transmission line.
The optical communication device according to any one of claims 1 to 11, wherein the receiver receives an optical signal branched by the turnout.
Further, a monitoring unit for monitoring an optical signal transmitted through the transmission line is provided.
The monitoring unit includes a plurality of receivers, a plurality of branching devices for branching an optical signal transmitted through the transmission line, a plurality of duplexing devices for combining or demultiplexing an input optical signal, and a modulator. And have
A turnout is provided in each of the plurality of transmission lines through which the optical signal demultiplexed by the combine demultiplexer is transmitted.
The modulator modulates the optical signal demultiplexed by the combine demultiplexer.
The optical communication device according to any one of claims 1 to 11, wherein the receiver receives an optical signal branched by the turnout.
An optical communication system having a plurality of subscriber devices and the optical communication device according to any one of claims 1 to 14.
The subscriber device is
An optical transmitter that transmits an optical signal of a set wavelength via a wavelength variable filter for the optical signal output from the light source.
Among the input optical signals, the optical receiver that receives the optical signal of the set wavelength, and
15. The optical communication system according to claim 15.
The subscriber device is
An optical transmitter that combines and transmits optical signals of different wavelengths output from each of multiple light sources,
Among the input optical signals, the optical receiver that receives the optical signal of the set wavelength and
15. The optical communication system according to claim 15.
The subscriber device is
An optical transmitter that combines and transmits optical signals of different wavelengths output from each of multiple light sources,
An optical receiver that demultiplexes the input optical signal and receives the demultiplexed optical signals of different wavelengths,
15. The optical communication system according to claim 15.
The subscriber device is
One of claims 15 to 18, further comprising a separation unit that outputs an optical signal transmitted from the optical transmission unit to a transmission line and outputs an optical signal input from the transmission line to the optical reception unit. The optical communication system described in.
An optical switch is connected to a plurality of transmission lines, and an optical signal input from one of the transmission lines is output to another transmission line.
The combined branching device branches the input optical signal to a plurality of ports of the optical switch and outputs or multiplexes the input signal to output the signal.
The optical switch control unit outputs at least the optical signal output from the junction branch to the plurality of ports to the other plurality of ports to which the transmission path corresponding to the transfer destination on the path to the communication destination is connected. The optical switch is controlled so that an optical signal input from the plurality of ports to the joint branching device is input from another plurality of ports to which a transmission path corresponding to a path from a communication source device is connected. Optical communication method.