Gateway device and control signal light receiving method

Abstract

Provided is a gateway device provided between a control device that controls at least one first user terminal that performs single-core bidirectional transmission and at least one second user terminal that performs two-core transmission. The gateway device comprises: a plurality of main signal control signal multiplexing / demultiplexing units that demultiplex an input optical signal into at least main signal light and control signal light; and a plurality of control signal transceivers that transmit and receive control signal light between the at least one user terminal and the at least one second user terminal via at least one of the plurality of main signal control signal multiplexing / demultiplexing units. Each of the plurality of control signal transceivers includes an output unit that outputs uplink control signal light transmitted from the at least one first user terminal or the at least one second user terminal to an optical reception unit.　

Description

Gateway device and control signal optical receiving method

[0001] The present invention relates to a gateway device and a control signal optical receiving method.

[0002] An optical communication system capable of optically connecting user terminals end-to-end has been proposed (see, for example, Patent Document 1). FIG. 4 is a diagram illustrating a method for opening an optical path in a conventional optical communication system S. As shown in FIG. 4, the conventional optical communication system S includes a user terminal 200, a filter 250, a user terminal 300, a filter 350, multiple control units 400-1 to 400-2, and multiple GW devices 500-1 to 500-2. For simplicity of explanation, FIG. 4 illustrates a case in which there is one user terminal 200 and one user terminal 300. FIG. 4 also illustrates a method for opening an optical path for connecting the user terminal 200 to the user terminal 300 with which it is communicating.

[0003] The user terminal 200 includes an optical main signal transceiver 210 and an optical control signal transceiver 220. The optical main signal transceiver 210 transmits and receives optical main signals to and from the user terminal 300, which is the communication partner. The optical control signal transceiver 220 transmits and receives optical control signals to and from the control unit 400-1. The filter 250 multiplexes or demultiplexes the input optical main signal and optical control signals.

[0004] The user terminal 300 includes an optical main signal transceiver 310 and an optical control signal transceiver 320. The optical main signal transceiver 310 transmits and receives optical main signals to and from the user terminal 200, which is the communication partner. The optical control signal transceiver 320 transmits and receives optical control signals to and from the control unit 400-2. The filter 350 multiplexes or demultiplexes the input optical main signal and optical control signal.

[0005] The control unit 400-1 includes a GW device control unit 410-1 and a user terminal control unit 420-1. The GW device control unit 410-1 controls the operation of the GW device 500-1. The user terminal control unit 420-1 manages the user terminal 200. The control unit 400-2 includes a GW device control unit 410-2 and a user terminal control unit 420-2. The GW device control unit 410-2 controls the operation of the GW device 500-2. The user terminal control unit 420-2 manages the user terminal 300.

[0006] The GW device 500-1 includes a multiplexing / demultiplexing unit 510-1, a control signal transmitting / receiving unit 520-1, and an optical distribution unit 530-1. The GW device 500-2 includes a multiplexing / demultiplexing unit 510-2, a control signal transmitting / receiving unit 520-2, and an optical distribution unit 530-2. Since the GW devices 500-1 and 500-2 have the same functional units, the functional units included in the GW device 500-1 will be described as an example. The multiplexing / demultiplexing unit 510-1 includes multiple filters 511. Each filter 511 is connected to a different filter 250 and multiplexes or demultiplexes the input control signal light and main signal light. The control signal light demultiplexed by the filter 511 is input to the control signal transmitting / receiving unit 520-1, and the main signal light demultiplexed by the filter 511 is input to the optical distribution unit 530-1.

[0007] The control signal transceiver unit 520-1 includes a plurality of control signal optical transceivers 521 and a switch 522. Each control signal optical transceiver 521 is connected to a different filter 511. Each control signal optical transceiver 521 converts the control signal light output from the filter 511 into a control signal that is an electrical signal, and outputs the control signal that is an electrical signal to the control unit 400-1 via the switch 522. Furthermore, each control signal optical transceiver 521 acquires the control signal output from the control unit 400-1 via the switch 522, converts the acquired control signal into a control signal light that is an optical signal, and outputs it to the filter 511. In this way, each control signal optical transceiver 521 transmits and receives control signal light to and from the user terminal 200 connected to the GW 500-1.

[0008] The optical distribution unit 530-1 inputs optical main signals transmitted from multiple user terminals 200 in the upstream direction (e.g., the direction from the user terminal 200 toward the user terminal 300), multiplexes the optical main signals having the same destination route, and outputs the multiplexed optical signals to the trunk network NW for each route. Also, the optical distribution unit 530-1 inputs optical multiplexed signals from multiple routes via the trunk network NW in the downstream direction (e.g., the direction from the user terminal 300 toward the user terminal 200), and outputs the required optical signals to each user terminal 200.

[0009] When a user terminal 200 is newly connected to the GW device 500-1, a link is established between the control signal optical transceiver 220 of the newly connected user terminal (hereinafter referred to as the "new connection device") and the control signal optical transceiver 521 of the GW device 500-1, and information required for registration and authentication of the new connection device is exchanged between the new connection device and the control unit 400-1, and the new connection device can be instructed on the emission wavelength to be used for transmission and reception. The new connection device transmits main signal light at the wavelength instructed by the control unit 400-1.

[0010] Furthermore, after the registration of the new connection device and the wavelength setting are completed, the GW device control unit 410-1 of the control unit 400-1 sets the optical distribution unit 530-1 of the GW device 500-1 so that the optical signal transmitted from the new connection device is forwarded to the user terminal 300, which is the communication partner. Similarly, the control unit 400-2 sets the optical distribution unit 530-2 of the GW device 500-2 so that the optical signal transmitted from the new connection device is forwarded to the user terminal 300, which is the communication partner. This makes it possible to open an optical path connecting the new connection device and the user terminal 300.

[0011] International Publication No. 2021 / 131202

[0012] As described above, when opening an optical path in the optical communication system S, it is necessary to exchange information required for user registration between the user terminals 200 and 300 and the user terminal control unit 420 of the control unit 400. Therefore, it is necessary to be able to establish a link between the control signal optical transceiver 521 of the GW device 500 and the control signal optical transceivers 220 and 320 of the user terminals 200 and 300.

[0013] Here, as shown in FIG. 5, a user terminal 200-1 (for example, an upstream control wavelength λ 1 ) that performs one-core bidirectional transmission to one GW device 500-1 is connected to the GW device 500-1. ２ , downstream control wavelength λ １ ) and a user terminal 200-2 (for example, an upstream control wavelength λ ３ , downstream control wavelength λ ３ 5, the GW device 500-1 is provided with a control signal optical transceiver 521-1 for the user terminal 200-1 that performs single-core bidirectional transmission, and a control signal optical transceiver 521-2 for the user terminal 200-2 that performs dual-core transmission.

[0014] The control signal optical transceiver 521-1 includes an upstream / downstream filter 524, an optical transmitter 525, and an optical receiver 526. The upstream / downstream filter 524 multiplexes or demultiplexes the upstream control signal light and the downstream control signal light. For example, the upstream / downstream filter 524 multiplexes or demultiplexes the upstream control signal light and the downstream control signal light with the wavelength λ １ to the filter 511-1, and the light of wavelength λ transmitted from the user terminal 200-1 is ２ The optical transmitter 525 outputs the downstream control wavelength λ corresponding to the user terminal 200-1 to the optical receiver 526. １ The optical receiver 526 transmits a downstream control signal light of the upstream control wavelength λ corresponding to the user terminal 200-1. ２ The upstream control signal light is received.

[0015] The control signal optical transceiver 521-2 includes an optical transmitter 527 and an optical receiver 528. The optical transmitter 527 transmits a downstream control wavelength λ 1 corresponding to the user terminal 200-2. ３ The optical receiver 528 transmits a downstream control signal light of the upstream control wavelength λ corresponding to the user terminal 200-2. ３ The upstream control signal light is received.

[0016] Furthermore, the GW device 500-1 needs to prepare different filters depending on the type of user terminal (single-core or dual-core). In the example shown in Fig. 5, the GW device 500-1 is provided with a filter 511-1 for the user terminal 200-1 that performs single-core transmission, and filters 511-2 and 511-3 for the user terminal 200-2 that performs dual-core transmission. The filter 511-1 for the user terminal 200-1 that performs single-core transmission is a filter for a wavelength λ １ , λ ２ The filters 511-2 and 511-3 for the user terminal 200-2, which performs two-core transmission, are filters that can multiplex or demultiplex the control signal light of wavelength λ ３ It is a filter that can multiplex or demultiplex the control signal light of one wavelength with the main signal light of another wavelength. Note that the wavelengths used in the explanation of the filter 511 are just an example.

[0017] As described above, when user terminals of different transmission method types (single-core and dual-core) are connected to one GW device 500-1, different types of control signal optical transceivers (control signal optical transceivers 521-1 and 521-2 in FIG. 5) and different types of filters (filter 511 in FIG. 5) must be provided according to the types of user terminals connected. This means that unnecessary functional units must also be provided or prepared, which can increase the cost of the device.

[0018] In order to reduce the cost of the equipment, it is conceivable to use the control signal optical transceiver 220-2 of the user terminal 200-2, which performs two-core transmission, as the same transceiver as the control signal optical transceiver 220-1 of the user terminal 200-1, which performs single-core transmission, so that the control signal optical transceiver and filter of the GW device 500-1 can be shared. However, since only one of the two cores used in the two-core system is used as a control signal, the remaining unused core cannot be monitored.

[0019] In view of the above circumstances, the present invention aims to provide a technology that can reduce equipment costs even when a user terminal that performs single-core bidirectional transmission and a user terminal that performs two-core transmission are connected.

[0020] One aspect of the present invention is a gateway device provided between a control device that controls one or more first user terminals that perform single-core bidirectional transmission and one or more second user terminals that perform two-core transmission, the gateway device comprising: a plurality of main signal / control signal multiplexing / demultiplexing units that demultiplex an input optical signal into at least main signal light and control signal light; and a plurality of control signal transceivers that transmit and receive control signal light between the one or more first user terminals and the one or more second user terminals via at least one of the plurality of main signal / control signal multiplexing / demultiplexing units, each of the plurality of control signal transceivers comprising an output unit that outputs upstream control signal light transmitted from the one or more first user terminals or the one or more second user terminals to an optical receiving unit.

[0021] One aspect of the present invention is a control signal optical reception method performed by a gateway device provided between a control device that controls one or more first user terminals performing single-core bidirectional transmission and one or more second user terminals performing two-core transmission, in which each of a plurality of control signal transmitters and receivers that transmit and receive control signal optical signals between the one or more first user terminals and the one or more second user terminals via at least one of a plurality of main signal and control signal multiplexing / demultiplexing units that demultiplex an input optical signal into at least main signal optical signals and control signal optical signals outputs upstream control signal optical signals transmitted from the one or more first user terminals or the one or more second user terminals to an optical receiving unit.

[0022] According to the present invention, even when a user terminal that performs single-core bidirectional transmission and a user terminal that performs two-core transmission are connected, it is possible to reduce the cost of the device.

[0023] Fig. 1 is a diagram illustrating a configuration example of an optical communication system according to a first embodiment. Fig. 2 is a sequence diagram illustrating a processing flow of the optical communication system according to the first embodiment. Fig. 3 is a diagram illustrating a configuration example of an optical communication system according to a second embodiment. Fig. 4 is a diagram for explaining a method for opening an optical path in a conventional optical communication system. Fig. 5 is a diagram for explaining a conventional problem.

[0024] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0025] First Embodiment Fig. 1 is a diagram showing an example configuration of an optical communication system 100 according to a first embodiment. The optical communication system 100 includes a GW device 10, a control unit 20, and a plurality of filters 25. A user terminal 30-1 is connected to the GW device 10 via an optical transmission line L1 and a filter 25-1. Furthermore, a user terminal 30-2 is connected to the GW device 10 via an optical transmission line L2 and filters 25-2 and 25-3. In the following description, when there is no need to distinguish between the user terminals 30-1 and 30-2, they will simply be referred to as user terminal 30.

[0026] The optical transmission paths L1 and L2 are, for example, optical fibers. In the optical communication system 100 of the first embodiment, an example will be described in which the user terminal 30-1 is a device that performs single-core bidirectional transmission, and the user terminal 30-2 is a device that performs two-core transmission. The user terminal 30-1 that performs single-core bidirectional transmission is connected to the GW device 10 via the same optical transmission path L1 for sending and receiving. The user terminal 30-2 that performs two-core transmission is connected to the GW device 10 via different optical transmission paths L2 for sending and receiving. Hereinafter, when distinguishing between the user terminal 30-1 that performs single-core bidirectional transmission and the user terminal 30-2 that performs two-core transmission, they may be referred to as the single-core user terminal 30-1 and the two-core user terminal 30-2.

[0027] Although not shown in Fig. 1 for simplicity, the optical communication system 100 includes multiple GW devices and multiple control units as shown in Fig. 4. The optical communication system 100 may include a control unit for each GW device, or may include one control unit for multiple GW devices. The GW device 10 is connected to another GW device or user terminal via an optical transmission path L at a port different from the port to which one user terminal 30 is connected. The same applies to the following embodiments.

[0028] In the following description, the direction from the user terminal 30 toward the control unit 20 is referred to as the upstream direction, and the direction from the control unit 20 toward the user terminal 30 is referred to as the downstream direction. The number of GW devices 10 and user terminals 30 is not particularly limited.

[0029] (Configuration of GW Device 10) The GW device 10 is a gateway device that constitutes a wavelength network, and accommodates one or more user terminals 30. The GW device 10 includes a multiplexing / demultiplexing unit 11, a control signal transmitting / receiving unit 12, and an optical distribution unit 13.

[0030] The multiplexing / demultiplexing unit 11 includes a plurality of filters 111. While FIG. 1 shows an example in which the multiplexing / demultiplexing unit 11 includes four filters 111, it is assumed that a single-core user terminal 30-1 and a dual-core user terminal 30-2 are mixed, and therefore three or more filters 111 are sufficient. Each filter 111 multiplexes or demultiplexes the input control signal light and main signal light. Each filter 111 has a first port 112, a second port 113, and a third port 114. The first port 112 of each filter 111 is connected to the filter 25 via an optical transmission path. The second port 113 of each filter 111 is connected to the control signal transmitting / receiving unit 12. The third port 114 of each filter 111 is connected to the optical distribution unit 13.

[0031] An optical signal transmitted from a connected user terminal 30 is input to a first port 112 of each filter 111 via a filter 25. Each filter 111 demultiplexes the optical signal input to the first port 112 into a main signal light and a control signal light according to the wavelength. The control signal light demultiplexed by each filter 111 is input to the control signal transmitting / receiving unit 12 via a second port 113, and the main signal light demultiplexed by the filter 111 is input to the optical distribution unit 13 via a third port 114.

[0032] Furthermore, each filter 111 receives the control signal light transmitted from the control signal transmitting / receiving unit 12 via the second port 113, and receives the main signal light transferred from the optical distribution unit 13 via the third port 114. Each filter 111 multiplexes the control signal light input to the second port 113 and the main signal light input to the third port 114. The optical signal multiplexed by each filter 111 is output to the filter 25 via the first port 112.

[0033] As described above, the filter 111 can be, for example, a wavelength filter having wavelength characteristics that reflect the wavelengths of the downstream control signal light and the upstream control signal light and transmit the wavelength band of the main signal light transmitted by the user terminal 30. Note that the wavelength characteristics of the filter 111 may also be characteristics that transmit the wavelengths of the downstream control signal light and the upstream control signal light and reflect the wavelength band of the main signal light transmitted by the user terminal 30. The filter 111 is one aspect of a main signal / control signal multiplexing / demultiplexing unit.

[0034] The control signal transmitting / receiving unit 12 includes a plurality of optical control signal transceivers 121 and a switch 122. One optical control signal transceiver 121 is connected to two filters 111. For example, the optical control signal transceiver 121-1 is connected to the filter 111-1 and the filter 111-2. Furthermore, for example, the optical control signal transceiver 121-2 is connected to the filter 111-3 and the filter 111-4. While FIG. 1 shows an example in which the control signal transmitting / receiving unit 12 includes two optical control signal transceivers 121, it is sufficient that there are two or more optical control signal transceivers 121.

[0035] Each control signal optical transceiver 121 converts the control signal light output from the filter 111 into an electrical control signal, and outputs the electrical control signal to the control unit 20 via the switch 122. Furthermore, each control signal optical transceiver 121 acquires the control signal output from the control unit 20 via the switch 122, converts the acquired control signal into an optical control signal light, and outputs it to the filter 111. In this way, each control signal optical transceiver 121 transmits and receives control signal light to and from the user terminal 30 connected to the GW 10.

[0036] The switch 122 connects the control unit 20 and each optical control signal transceiver 121. For example, the switch 122 outputs a control signal transmitted from the control unit 20 to the corresponding optical control signal transceiver 121, and outputs a control signal transmitted from each optical control signal transceiver 121 to the control unit 20.

[0037] The control signal optical transceiver 121 includes a first port 123, a second port 124, an upstream / downstream filter 125, an optical transmitter 126, a multiplexer / demultiplexer 127, and an optical receiver 128. The upstream / downstream filter 125 multiplexes or demultiplexes the upstream control signal light and the downstream control signal light. The upstream / downstream filter 125 has wavelength characteristics that reflect the wavelength of the downstream control signal light transmitted from the optical transmitter 126 and transmit the wavelength of the upstream control signal light transmitted from the user terminal 30. Alternatively, the wavelength characteristics of the upstream / downstream filter 125 may be characteristics that transmit the wavelength of the downstream control signal light and reflect the wavelength of the upstream control signal light.

[0038] The upstream / downstream filter 125 is connected to the filter 111 via the first port 123. Furthermore, the upstream / downstream filter 125 is connected to the optical transmitter 126 and the multiplexer / demultiplexer 127. The upstream / downstream filter 125 outputs the downstream control signal light transmitted from the optical transmitter 126 to the filter 111 via the first port 123. The upstream / downstream filter 125 outputs the upstream control signal light output from the filter 111 to the multiplexer / demultiplexer 127 according to the wavelength. In the following description, it is assumed that the upstream / downstream filter 125 is configured to filter the downstream control signal light of wavelength λ ２ It is assumed that the setting is such that the light of the wavelengths .gtoreq.1 and .gtoreq.2 is output to the multiplexing / demultiplexing unit 127.

[0039] In response to an instruction output from the control unit 20, the optical transmitter 126 transmits a wavelength λ 1 to the user terminal 30. １ In this example, the optical transmitter 126 transmits a downstream control signal light of wavelength λ １ However, the wavelength may be any wavelength as long as it is different from the wavelength of the upstream control signal light transmitted by the single-core user terminal 30-1.

[0040] The multiplexing / demultiplexing unit 127 multiplexes the upstream control signal light transmitted from the single-core user terminal 30-1 or the upstream control signal light transmitted from the two-core user terminal 30-2. The multiplexing / demultiplexing unit 127 is connected to the filter 111 via the second port 124. The multiplexing / demultiplexing unit 127 is further connected to the upstream / downstream filter 125 and the optical receiving unit 128. This allows the multiplexing / demultiplexing unit 127 to output at least one of the upstream control signal light demultiplexed by the upstream / downstream filter 125 or the upstream control signal light input via the second port 124 to the optical receiving unit 128.

[0041] The multiplexing / demultiplexing unit 127 is, for example, an optical coupler. The optical coupler multiplexes or demultiplexes the input optical signal. Note that the multiplexing / demultiplexing unit 127 may be configured to use a multiplexer / demultiplexer instead of an optical coupler, which can multiplex or demultiplex optical signals having a plurality of wavelengths (for example, wavelengths λ １ and wavelength λ ２ 1, the multiplexing / demultiplexing unit 127 receives the upstream control signal light transmitted from the single-core user terminal 30-1 via the upstream / downstream filter 125, and receives the upstream control signal light transmitted from the two-core user terminal 30-2 without passing through the upstream / downstream filter 125. The multiplexing / demultiplexing unit 127 is one aspect of the output unit.

[0042] The optical receiving unit 128 receives the upstream control signal light output from the multiplexing / demultiplexing unit 127. The optical receiving unit 128 receives at least one of the upstream control signal light transmitted from the one-core user terminal 30-1 and the upstream control signal light transmitted from the two-core user terminal 30-2. The optical receiving unit 128 converts the received upstream control signal light into an electrical signal and outputs it to the control unit 20 via the switch 122.

[0043] In the direction from the user terminal 30 toward the user terminal of the communication partner, the optical distribution unit 13 inputs optical main signals transmitted from multiple user terminals 30, multiplexes the optical main signals having the same destination route, and outputs the multiplexed optical signals to the trunk network NW for each route. In addition, in the direction from the user terminal of the communication partner toward the user terminal 30, the optical distribution unit 13 inputs multiplexed optical signals from multiple routes via the trunk network NW, and outputs the required optical signals to each user terminal 30.

[0044] (Configuration of the control unit 20) The control unit 20 controls the GW device 10 and the user terminal 30. Here, the control of the GW device 10 includes, for example, setting up connections between ports of the optical distribution unit 13 (for example, setting up a forwarding path). The control of the user terminal 30 includes, for example, processing such as authentication and registration with a new connection device, allocation of an emission wavelength to the user terminal 30, and issuing instructions to stop light and change wavelengths.

[0045] The control unit 20 includes a user terminal control unit and a GW device control unit. The user terminal control unit performs the above-described control on user terminals 30 connected to the GW device 10 (including, for example, user terminals 30 already connected to the GW device 10 and newly connected devices).

[0046] The GW device control unit performs routing control in the GW device 10 so that the user terminal 30 can communicate with the subscriber device that is the communication partner.

[0047] (Configuration of filter 25) The filter 25 multiplexes or demultiplexes the input control signal optical and main signal optical. The filter 25 has a first port 251, a second port 252, and a third port 253. The first port 251 of the filter 25 is connected to the control signal optical transceiver 32 of the user terminal 30. The second port 252 of the filter 25 is connected to the main signal transceiver 31 of the user terminal 30. The third port 253 of the filter 25 is connected to the filter 111 of the GW device 10 via an optical transmission path.

[0048] The filter 25 demultiplexes the optical signal input to the third port 253 into an optical main signal and an optical control signal according to their wavelengths. The optical control signal demultiplexed by the filter 25 is input to the optical control signal transceiver 32 of the user terminal 30 via the first port 251, and the optical main signal demultiplexed by the filter 25 is input to the optical main signal transceiver 31 of the user terminal 30 via the second port 252.

[0049] Furthermore, the filter 25 receives an upstream control signal optical signal transmitted from the control signal optical transceiver 32 of the user terminal 30 via a first port 251, and receives a main signal optical signal transmitted from the main signal transceiver 31 of the user terminal 30 via a second port 252. The filter 25 multiplexes the control signal optical signal input to the first port 251 and the main signal optical signal input to the second port 252. The optical signal multiplexed by the filter 25 is output to the GW device 10 via a third port 253 and the optical transmission path.

[0050] As described above, the filter 25 can be, for example, a wavelength filter having wavelength characteristics that reflect the wavelengths of the downstream control signal light and the upstream control signal light and transmit the wavelength band of the main signal light transmitted by the user terminal 30. Note that the wavelength characteristics of the filter 25 may also be characteristics that transmit the wavelengths of the downstream control signal light and the upstream control signal light and reflect the wavelength band of the main signal light transmitted by the user terminal 30.

[0051] (Configuration of the single-core user terminal 30-1) The single-core user terminal 30-1 includes a main signal transceiver 31-1 and a control signal optical transceiver 32-1. The main signal transceiver 31-1 transmits and receives main signal light with a communication device of a communication partner via a transmission / reception port 311-1. The transmission / reception port 311-1 is a port used for both transmitting and receiving optical signals. The wavelength of the main signal light transmitted by the main signal transceiver 31-1 included in the single-core user terminal 30-1 may be assigned to the single-core user terminal 30-1 by the control unit 20 and notified by the control unit 20. The notification of the wavelength can be notified as a downstream control signal. Note that the single-core user terminal 30-1 uses the same optical transmission line L1 for transmission and reception. Therefore, it is desirable that the wavelength used by the single-core user terminal 30-1 for transmission is different from the wavelength used for reception.

[0052] The control signal optical transceiver 32-1 is used to transmit and receive control signals. The control signal optical transceiver 32-1 includes an optical transmitter 321-1, an optical receiver 322-1, an upstream / downstream filter 323-1, and a transmission / reception port 324-1. The optical transmitter 321-1 transmits upstream control signal light at a predetermined wavelength (for example, wavelength λ ２The optical transmitter 321-1 transmits at a predetermined wavelength (for example, wavelength λ ２ The optical receiver 322-1 receives an upstream control signal light of a predetermined wavelength (for example, wavelength λ １ The optical receiver 322-1 receives downstream control signal light transmitted at a predetermined wavelength (for example, wavelength λ １ The optical receiver 322-1 receives a downstream control signal light from the optical fiber 322-1. The optical receiver 322-1 has a function of detecting and demodulating the optical signal.

[0053] The upstream / downstream filter 323-1 multiplexes or demultiplexes the upstream control signal light and the downstream control signal light. The upstream / downstream filter 323-1 has wavelength characteristics that reflect the wavelength of the upstream control signal light transmitted from the optical transmitter 321-1 and transmit the wavelength of the downstream control signal light transmitted from the GW device 10. Alternatively, the wavelength characteristics of the upstream / downstream filter 323-1 may be characteristics that transmit the wavelength of the upstream control signal light and reflect the wavelength of the downstream control signal light.

[0054] The upstream / downstream filter 323-1 is connected to the optical transmitter 321-1, the optical receiver 322-1, and the transmission / reception port 324-1. The upstream / downstream filter 323-1 outputs the upstream control signal light transmitted from the optical transmitter 321-1 to the filter 25-1 via the transmission / reception port 324-1. The upstream / downstream filter 323-1 outputs the downstream control signal light transmitted from the GW device 10 to the optical receiver 322-1 according to the wavelength. In the following description, it is assumed that the upstream / downstream filter 323-1 outputs the downstream control signal light transmitted from the GW device 10 according to the wavelength λ １ It is assumed that the setting is such that the light of the optical receiver 322-1 is output to the optical receiver 322-2.

[0055] (Configuration of the two-core user terminal 30-2) The two-core user terminal 30-2 includes a main signal transceiver 31-2 and an optical control signal transceiver 32-2. Unlike the single-core user terminal 30-1, the two-core user terminal 30-2 has the main signal transceiver 31-2 and the optical control signal transceiver 32-2 connected to different filters 25. The main signal transceiver 31-2 transmits an optical main signal to a communication device of a communication partner via a transmission port 312-2.

[0056] The transmission port 312-2 is a port used for transmitting the optical main signal. The transmission port 312-2 is connected to the second port 252-2 of the filter 25-2 via an optical transmission line. Therefore, the optical main signal transmitted from the optical main signal transceiver 31-2 is input to the second port 252-2 of the filter 25-2 via the transmission port 312-2.

[0057] The wavelength of the optical main signal transmitted by the optical main signal transceiver 31-2 included in the two-core user terminal 30-2 may be assigned to the two-core user terminal 30-1 by the control unit 20 and notified by the control unit 20. The notification of the wavelength can be notified as a downstream control signal. The two-core user terminal 30-2 uses different optical transmission lines L2 for transmission and reception. Therefore, the wavelength used by the two-core user terminal 30-2 for transmission and the wavelength used for reception may be the same as or different from each other. The optical main signal transceiver 31-2 receives the optical main signal transmitted from the communication device of the other party via the reception port 313-2. The reception port 313-2 is a port used to receive the optical main signal. The reception port 313-2 is connected to the second port 252-3 of the filter 25-3 via an optical transmission line.

[0058] The control signal optical transceiver 32-2 is used to transmit and receive control signals. The control signal optical transceiver 32-2 includes an optical transmitter 321-2, an optical receiver 322-2, a receiving port 325-2, and a transmitting port 326-2. The optical transmitter 321-2 transmits an upstream control signal light at a predetermined wavelength (for example, wavelength λ １ The optical transmitter 321-2 transmits at a predetermined wavelength (for example, wavelength λ １ The optical receiver 322-2 receives an upstream control signal light of a predetermined wavelength (for example, wavelength λ １ The optical receiver 322-2 receives downstream control signal light transmitted at a predetermined wavelength (for example, wavelength λ １ The optical receiver 322-2 has the function of detecting and demodulating the optical signal.

[0059] The receiving port 325-2 is a port used to receive downstream control signal light. The receiving port 325-2 is connected to the first port 251-2 of the filter 25-2 via an optical transmission line. The transmitting port 326-2 is a port used to transmit upstream control signal light. The transmitting port 326-2 is connected to the first port 251-3 of the filter 25-3 via an optical transmission line.

[0060] When a user terminal 30, before an optical path is opened, is newly connected to the GW device 10, it exchanges information necessary for registration and authentication and for opening an optical path with the control unit 20. The information necessary for opening an optical path includes, for example, information on the wavelengths used for transmission and reception, and information indicating the communication device to be communicated with. The user terminal 30 may output an upstream control signal light to the control unit 20 as an optical signal with a wavelength different from that of the main signal light. The user terminal 30 is, for example, an ONU (Optical Network Unit) installed in a subscriber's premises.

[0061] The user terminal 30 may have the filter 25 built-in.

[0062] 2 is a sequence diagram showing the flow of processing in the optical communication system 100 according to the first embodiment. In explaining the flow of processing, it is assumed that the connections of the user terminals 30 are as shown in FIG.

[0063] Assume that a user connects one optical transmission line L1 to the single-core user terminal 30-1 via a filter 25-1 to connect to the GW device 10 (step S101). As a result, as shown in Fig. 1, the control signal optical transceiver 32-1 of the single-core user terminal 30-1 is connected to the first port 251-1 of the filter 25-1, and the main signal transceiver 31-1 of the single-core user terminal 30-1 is connected to the second port 252-1 of the filter 25-1.

[0064] The single-core user terminal 30-1 connects to the GW device 10 via the filter 25-1, and then generates an upstream control signal including instructions requesting authentication, registration, etc. The control signal optical transceiver 32-1 of the single-core user terminal 30-1 converts the generated upstream control signal into an optical signal with a wavelength λ ２is sent out as an upstream control signal light (step S102).

[0065] The wavelength λ 2 sent from the control signal optical transceiver 32-1 of the single-core user terminal 30-1 ２ The upstream control signal light of wavelength λ is input to the first port 112-1 of the filter 111-1 of the GW device 10 via the filter 25-1. ２ The upstream control signal light of wavelength λ is outputted to the control signal optical transceiver 121-1 via the second port 113-1. The second port 113-1 of the filter 111-1 is connected to the first port 123-1 of the control signal optical transceiver 121-1 via an optical wiring. Therefore, the upstream control signal light of wavelength λ is outputted from the second port 113-1 of the filter 111-1. ２ The upstream control signal light is input to the first port 123-1 of the control signal optical transceiver 121-1.

[0066] The wavelength λ input to the first port 123-1 of the control signal optical transceiver 121-1 ２ The upstream control signal light of the wavelength λ is input to the upstream / downstream filter 125-1. ２ The upstream / downstream filter 125-1 separates the upstream control signal light of wavelength λ ２ to the optical receiving unit 128. As a result, the upstream / downstream filter 125-1 outputs the light of the input wavelength λ ２ The multiplexer / demultiplexer 127-1 outputs the upstream control signal light of the wavelength λ ２ The upstream control signal light of λ 1 is multiplexed with the optical signal input from the second port 124-1, and the multiplexed signal is output to the optical receiving unit 128-1. However, no optical signal is input from the second port 124-1. Therefore, the multiplexing / demultiplexing unit 127-1 multiplexes the input wavelength λ 1 ２ The upstream control signal light is output to the optical receiver 128-1.

[0067] The optical receiving unit 128-1 receives the input wavelength λ ２The optical receiving unit 128-1 detects and demodulates the upstream control signal light of the signal 128-1. The optical receiving unit 128-1 outputs the demodulated upstream control signal to the control unit 20 via a control line (not shown) (step S103).

[0068] In response to receiving the upstream control signal, the control unit 20 recognizes that the new connection device has been connected to the GW device 10. Then, the control unit 20 transmits a downstream control signal to the control signal optical transceiver 121-1 that includes the optical receiving unit 128-1 that output the upstream control signal (step S104).

[0069] In response to receiving a downstream control signal transmitted from the control unit 20, the control signal optical transceiver 121-1 transmits a downstream control signal of wavelength λ 1 from the optical transmitting unit 126-1. １ The downstream control signal light of wavelength λ 1 transmitted from the optical transmitter 126-1 is transmitted (step S105). １ The downstream control signal light is input to the upstream / downstream filter 125-1. The upstream / downstream filter 125-1 filters the input wavelength λ １ The downstream control signal light of wavelength λ 1 is output to the filter 111-1 via the first port 123-1. １ and the main signal light transferred from the optical distribution unit 13. Here, the filter 111-1 does not have the main signal light transferred from the optical distribution unit 13. Therefore, the filter 111-1 multiplexes the downstream control signal light of wavelength λ 1 output from the upstream / downstream filter 125-1. １ The downstream control signal light is output to the filter 25-1 via the first port 112-1.

[0070] The filter 25-1 receives the input wavelength λ １ The downstream control signal light of wavelength λ 1 input to the control signal light transceiver 32-1 is output to the control signal light transceiver 32-1. １ The downstream control signal light is output to the optical receiver 322-1 by the upstream / downstream filter 323-1. １ The downstream control signal light is received (step S106).

[0071] Upon receiving the downstream control signal light, the single-core user terminal 30-1 exchanges control signal light containing information necessary for authentication, registration, and optical path opening with the control unit 20 (step S107).

[0072] Next, suppose that the user connects the two optical transmission lines L2 to the dual-core user terminal 30-2 via the filters 25-2 and 25-3, thereby connecting to the GW device 10 (step S108). As a result, as shown in Fig. 1, suppose that the control signal optical transceiver 32-2 of the dual-core user terminal 30-2 is connected to the first port 251-2 of the filter 25-2 and the first port 251-3 of the filter 25-3, and the main signal transceiver 31-2 of the dual-core user terminal 30-2 is connected to the second port 252-2 of the filter 25-2 and the second port 252-3 of the filter 25-3.

[0073] The two-core user terminal 30-2, after connecting to the GW device 10 via 25-2 and 25-3, generates an upstream control signal including instructions requesting authentication, registration, etc. The control signal optical transceiver 32-2 of the two-core user terminal 30-2 converts the generated upstream control signal into an optical signal with a wavelength λ ２ is sent out as an upstream control signal light (step S109).

[0074] The wavelength λ 2 transmitted from the control signal optical transceiver 32-2 of the two-core user terminal 30-2 １ The upstream control signal light of wavelength λ is input to the first port 112-4 of the filter 111-4 of the GW device 10 via the filter 25-3. １ The upstream control signal light of wavelength λ is outputted to the control signal optical transceiver 121-2 via the second port 113-4. The second port 113-4 of the filter 111-4 is connected to the second port 124-2 of the control signal optical transceiver 121-2 via an optical wiring. Therefore, the upstream control signal light of wavelength λ is outputted from the second port 113-4 of the filter 111-4. １ The upstream control signal light is input to the second port 124-2 of the control signal optical transceiver 121-2.

[0075] The wavelength λ input to the second port 124-2 of the control signal optical transceiver 121-2 １The upstream control signal light of wavelength λ is input to the multiplexer / demultiplexer 127-2. １ The upstream control signal light of λ 1 is multiplexed with the optical signal input from the upstream / downstream filter 125-2, and the multiplexed signal is output to the optical receiving unit 128-2. However, no optical signal is input from the upstream / downstream filter 125-2. Therefore, the multiplexer / demultiplexer 127-2 multiplexes the input wavelength λ 1 １ The upstream control signal light is output to the optical receiver 128-2.

[0076] The optical receiving unit 128-2 receives the input wavelength λ １ The optical receiving unit 128-2 detects and demodulates the upstream control signal light of the signal 128-2. The optical receiving unit 128-2 outputs the demodulated upstream control signal to the control unit 20 via a control line (not shown) (step S110).

[0077] In response to receiving the upstream control signal, the control unit 20 recognizes that the new connection device has been connected to the GW device 10. Then, the control unit 20 transmits a downstream control signal to the control signal optical transceiver 121-2 that includes the optical receiving unit 128-2 that output the upstream control signal (step S111).

[0078] In response to receiving the downstream control signal transmitted from the control unit 20, the control signal optical transceiver 121-2 transmits a downstream control signal of wavelength λ 1 from the optical transmitting unit 126-2. １ The downstream control signal light of wavelength λ 1 transmitted from the optical transmitter 126-2 is transmitted (step S112). １ The downstream control signal light is input to the upstream / downstream filter 125-2. The upstream / downstream filter 125-2 filters the input wavelength λ １ The downstream control signal light of wavelength λ 1 is output to the filter 111-3 via the first port 123-2. １ and the main signal light transferred from the optical distribution unit 13. Here, the filter 111-3 does not have the main signal light transferred from the optical distribution unit 13. Therefore, the filter 111-3 multiplexes the downstream control signal light of wavelength λ 1 output from the upstream / downstream filter 125-2. １ The downstream control signal light is output to the filter 25-2 via the first port 112-3.

[0079] The filter 25-2 receives the input wavelength λ １ The downstream control signal light of wavelength λ 1 input to the control signal optical transceiver 32-2 is output to the control signal optical transceiver 32-2. １ The downstream control signal light is output to the optical receiver 322-2 via the receiving port 325-2. １ The downstream control signal light is received (step S113).

[0080] Upon receiving the downstream control signal light, the two-core user terminal 30-2 exchanges control signal light containing information necessary for authentication, registration, and optical path opening with the control unit 20 (step S114).

[0081] According to the optical communication system 100 configured as described above, by connecting the single-core user terminal 30-1 to a port having an upstream / downstream filter 125 in the control signal optical transceiver 121 of the GW device 10 and connecting the transmitting side and receiving side of the two-core user terminal 30-2 in the correct direction, when the control signal optical transceiver 121 and filter 111 of the GW device 10 are made common, control signal light can be transmitted and received between the GW device 10 and the user terminal 30 regardless of the type of transmission method (single-core or two-core) of the user terminal 30. Therefore, regardless of the type of transmission method of the connected user terminal (single-core user terminal, two-core user terminal), it is sufficient to prepare a common filter 111 and control signal optical transceiver 121. Therefore, even when a user terminal performing single-core bidirectional transmission and a user terminal performing two-core transmission are connected, it is possible to suppress device costs.

[0082] Second Embodiment In the first embodiment, a case where a single-core user terminal and a dual-core user terminal are user terminals that support continuous signals has been described. In the second embodiment, a configuration will be described where a single-core user terminal is a user terminal that supports burst signals (user terminal that supports time division multiplexing).

[0083] 3 is a diagram showing an example of the configuration of an optical communication system 100a according to the second embodiment. The optical communication system 100a includes a GW device 10a, a control unit 20, and a plurality of filters 25. A user terminal 30a-1 is connected to the GW device 10a via an optical transmission line L1 and a filter 25-1. Furthermore, a user terminal 30a-2 is connected to the GW device 10a via an optical transmission line L2 and filters 25-2 and 25-3.

[0084] In the optical communication system 100a of the second embodiment, an example will be described in which the user terminal 30a-1 is a device that performs single-core bidirectional transmission, and the user terminal 30a-2 is a device that performs dual-core transmission. The user terminal 30a-1 that performs single-core bidirectional transmission is connected to the GW device 10a via the same optical transmission line L1 for sending and receiving. The user terminal 30a-2 that performs dual-core transmission is connected to the GW device 10a via different optical transmission lines L2 for sending and receiving. Hereinafter, the user terminal 30a-1 that performs single-core bidirectional transmission will be referred to as the single-core user terminal 30a-1, and the user terminal 30a-2 that performs dual-core transmission will be referred to as the dual-core user terminal 30a-2. The configuration of the dual-core user terminal 30a-2 is the same as in the first embodiment.

[0085] (Configuration of the single-core user terminal 30a-1) The single-core user terminal 30a-1 transmits and receives control signal optical signals to and from the GW device 10a by time division multiplexing. The single-core user terminal 30a-1 includes a main signal transceiver 31-1 and a control signal optical transceiver 32a-1. The main signal transceiver 31-1 transmits and receives main signal optical signals to and from a communication device of a communication partner via a transmission / reception port 311-1. The wavelength of the main signal optical signals transmitted by the main signal transceiver 31-1 included in the single-core user terminal 30a-1 may be assigned to the single-core user terminal 30a-1 by the control unit 20 and notified by the control unit 20. The notification of the wavelength can be notified as a downstream control signal.

[0086] The control signal optical transceiver 32a-1 is used to transmit and receive control signals. The control signal optical transceiver 32a-1 includes an optical transmitter 327-1, an optical receiver 328-1, a multiplexer / demultiplexer 329-1, and a transmission / reception port 324-1. The optical transmitter 327-1 transmits an upstream control signal light at a predetermined wavelength (for example, wavelength λ １The optical transmitter 327-1 transmits at a predetermined wavelength (for example, wavelength λ １ The optical receiver 328-1 receives an upstream control signal light of a predetermined wavelength (for example, wavelength λ １ The optical receiver 328-1 receives downstream control signal light transmitted at a predetermined wavelength (for example, wavelength λ １ ) receives a downstream control signal light. The optical receiving unit 328-1 has the function of detecting and demodulating an optical signal. In this way, the single-core user terminal 30a-1 can use the same wavelength for both upstream and downstream to accommodate burst signals. That is, in the second embodiment, the single-core user terminal 30a-1 can use the same wavelength for both transmission and reception.

[0087] The multiplexer / demultiplexer 329-1 multiplexes the upstream control signal light transmitted from the optical transmitter 327-1. The multiplexer / demultiplexer 329-1 demultiplexes the optical signal input from the transmission / reception port 324-1. The multiplexer / demultiplexer 329-1 is, for example, an optical coupler.

[0088] The single-core user terminal 30a-1 and the dual-core user terminal 30a-2 may have a built-in filter 25.

[0089] (Configuration of GW device 10a) The GW device 10a is an optical node device that constitutes a wavelength network, and accommodates one or more single-core user terminals 30a-1 and one or more dual-core user terminals 30-2. The GW device 10a includes a multiplexing / demultiplexing unit 11, a control signal transmitting / receiving unit 12a, and an optical distribution unit 13.

[0090] The control signal transceiver 12a includes a plurality of optical control signal transceivers 121a and a switch 122. One optical control signal transceiver 121a is connected to two filters 111. For example, the optical control signal transceiver 121a-1 is connected to the filter 111-1 and the filter 111-2. Furthermore, for example, the optical control signal transceiver 121a-2 is connected to the filter 111-3 and the filter 111-4. While FIG. 3 shows an example of a configuration in which the control signal transceiver 12a includes two optical control signal transceivers 121a, it is sufficient that there are two or more optical control signal transceivers 121a.

[0091] Each control signal optical transceiver 121a converts the control signal light output from the filter 111 into an electrical control signal, and outputs the electrical control signal to the control unit 20 via the switch 122. Furthermore, each control signal optical transceiver 121a acquires the control signal output from the control unit 20 via the switch 122, converts the acquired control signal into an optical control signal light, and outputs it to the filter 111. In this way, each control signal optical transceiver 121a transmits and receives control signal light to and from the single-core user terminal 30a-1 and the dual-core user terminal 30-2 connected to the GW 10a.

[0092] The switch 122 connects the control unit 20 and each optical control signal transceiver 121 a. For example, the switch 122 outputs a control signal transmitted from the control unit 20 to the corresponding optical control signal transceiver 121 a, and outputs a control signal transmitted from each optical control signal transceiver 121 a to the control unit 20.

[0093] The control signal optical transceiver 121a includes a first port 123, a second port 124, an optical transmitter 126, a multiplexing / demultiplexing unit 127, an optical receiving unit 128, and an optical transmitter 129. The control signal optical transceiver 121a differs in configuration from the control signal optical transceiver 121 in that it does not include the upstream / downstream filter 125, that it newly includes the optical transmitter 129, and that the connection relationship of the multiplexing / demultiplexing unit 127 is different. The following description will focus on the differences from the control signal optical transceiver 121.

[0094] The optical transmitter 126 transmits a signal of a specific wavelength (for example, wavelength λ １ The optical transmitter 126 transmits a downstream control signal light of a specific wavelength (for example, wavelength λ ) for the single-core user terminal 30-1. １ ) as a burst signal. The optical transmitting unit 126 may stop emitting light when the optical receiving unit 128 receives an upstream control signal light as a burst signal. For example, the optical transmitting unit 126 operates in response to an instruction from the control unit 20 when the new connecting device is a single-core user terminal 30-1. The control unit 20 may determine that the new connecting device is a user terminal 30 that performs single-core bidirectional transmission by a notification from the new connecting device, or may determine this when a burst signal is received.

[0095] The multiplexing / demultiplexing unit 127 multiplexes the upstream control signal light of a burst signal transmitted from the single-core user terminal 30-1 or the upstream control signal light of a continuous signal transmitted from the two-core user terminal 30-2. The multiplexing / demultiplexing unit 127 is connected to the filter 111 via the first port 123. The multiplexing / demultiplexing unit 127 is further connected to the optical transmitting unit 126 and the optical receiving unit 128. This allows the multiplexing / demultiplexing unit 127 to output at least either the upstream control signal light of a burst signal or the upstream control signal light of a continuous signal input via the first port 123 to the optical receiving unit 128.

[0096] The multiplexing / demultiplexing unit 127 is, for example, an optical coupler. Note that the multiplexing / demultiplexing unit 127 may be configured to use a multiple wavelength (for example, wavelength λ １ and wavelength λ ２ The optical receiver 128 receives the upstream control signal light transmitted from the user terminal 30.

[0097] The optical receiving unit 128 receives the upstream control signal light output from the multiplexing / demultiplexing unit 127. For example, the optical receiving unit 128 receives the upstream control signal light, which is a burst signal transmitted from the single-core user terminal 30-1, or the upstream control signal light, which is a continuous signal transmitted from the two-core user terminal 30-2. The optical receiving unit 128 converts the received upstream control signal light into an electrical signal and outputs it to the control unit 20 via the switch 122.

[0098] The optical transmitter 129 transmits a signal of a specific wavelength (for example, wavelength λ １ The optical transmitter 129 transmits a downstream control signal light of a specific wavelength (for example, wavelength λ １ ) as a continuous signal. For example, the optical transmitting unit 129 operates in response to an instruction from the control unit 20 when the new connecting device is a two-core user terminal 30-2. The control unit 20 may determine that the new connecting device is a user terminal 30 that performs two-core transmission by a notification from the new connecting device, or may determine that the new connecting device is a user terminal 30 that performs two-core transmission by receiving a continuous signal.

[0099] The optical communication system 100a configured as above can also be applied to a time division multiplexing system.

[0100] Some of the functional units of the control unit 20 in the above-described embodiment may be implemented by a computer. In this case, a program for implementing the functions may be recorded on a computer-readable recording medium, and the program recorded on the recording medium may be read into a computer system and executed. Note that the term "computer system" here includes hardware such as an OS (Operating System) and peripheral devices.

[0101] Furthermore, "computer-readable recording media" refers to portable media such as flexible disks, optical magnetic disks, ROMs (Read Only Memory), and CD-ROMs, as well as storage devices such as hard disks built into computer systems. Furthermore, "computer-readable recording media" may also include devices that dynamically store programs for a short period of time, such as communication lines used when transmitting programs over networks like the Internet or communication lines like telephone lines, or devices that store programs for a fixed period of time, such as volatile memory within the computer systems that serve as servers or clients. Furthermore, the programs may be designed to realize some of the aforementioned functions, or may be capable of realizing the aforementioned functions in combination with programs already stored in the computer system, or may be realized using programmable logic devices such as FPGAs (Field Programmable Gate Arrays).

[0102] Although an embodiment of the present invention has been described in detail above with reference to the drawings, the specific configuration is not limited to this embodiment, and includes designs within the scope of the gist of the present invention.

[0103] The present invention can be applied to a technique for opening an optical path.

[0104] 10, 10a...GW device, 11...Multiplexing / demultiplexing unit, 12, 12a...Control signal transmitting / receiving unit, 13...Optical distribution unit, 20...Control unit, 30...User terminal, 30-1, 30a-1...1-core user terminal, 30-2...2-core user terminal, 31...Main signal transceiver, 32...Control signal optical transceiver, 100, 100a...Optical communication system, 111, 111-1 to 111-4...Filter, 121, 121-1 to 121-2, 121a-1 to 121a-2...Control signal optical transceiver, 122...Switch, 123, 123-1 to 123-2...First port, 124, 124-1 to 124-2...Second port, 125, 125-1 to 125-2...Upstream / downstream filter 126, 126-1 to 126-2...optical transmitting units, 127, 127-1 to 127-2...multiplexing / demultiplexing units, 128, 128-1 to 128-2...optical receiving units, 129, 129-1 to 129-2...optical transmitting units, 311...transmitting / receiving ports, 321, 321-1 to 321-2...optical transmitting units, 322, 322-1 to 322-2...optical receiving units, 323, 323-1...upstream / downstream filters, 324, 324-1...transmitting / receiving ports, 325, 325-2...receiving ports, 326, 326-2...transmitting ports, 327-1...optical transmitting units, 328-1...optical receiving units, 329-1...multiplexing / demultiplexing units

Claims

1. A gateway device provided between a control device that controls one or more first user terminals that perform single-core bidirectional transmission and one or more second user terminals that perform dual-core transmission, comprising: a plurality of main signal and control signal multiplexing / demultiplexing sections that demultiplex an input optical signal into at least main signal light and control signal light; and a plurality of control signal transceivers that transmit and receive control signal light between the one or more first user terminals and the one or more second user terminals via at least one of the plurality of main signal and control signal multiplexing / demultiplexing sections, each of the plurality of control signal transceivers comprising: an output section that outputs upstream control signal light transmitted from the one or more first user terminals or the one or more second user terminals to an optical receiving section.

2. The gateway device according to claim 1, further comprising an upstream / downstream filter that outputs upstream control signal light transmitted from the one or more first user terminals to the output unit according to wavelength, and the output unit outputs the upstream control signal light output from the upstream / downstream filter to the optical receiving unit.

3. A gateway device as described in claim 1 or 2, wherein the output unit acquires the upstream control signal light transmitted from the one or more second user terminals from one of the plurality of main signal and control signal multiplexing / demultiplexing units to which the one or more second user terminals that are the source of the upstream control signal light are connected, and outputs the acquired upstream control signal light to the optical receiving unit.

4. The gateway device according to claim 2, wherein the output unit is an optical coupler that multiplexes or branches input optical signals, or a wavelength filter that multiplexes light of multiple wavelengths.

5. The gateway device according to claim 1, further comprising: one or more first optical transmitting units that transmit burst signals to the one or more first user terminals; and one or more second optical transmitting units that transmit continuous signals to the one or more second user terminals, wherein the output unit further outputs the burst signals transmitted from the one or more first optical transmitting units to the one or more first user terminals.

6. A control signal optical reception method performed by a gateway device provided between a control device that controls one or more first user terminals performing single-core bidirectional transmission and one or more second user terminals performing dual-core transmission, wherein each of a plurality of control signal transmitters and receivers that transmit and receive control signal optical signals between the one or more first user terminals and the one or more second user terminals via at least one of a plurality of main signal and control signal multiplexing / demultiplexing sections that demultiplex an input optical signal into at least main signal optical signals and control signal optical signals outputs upstream control signal optical signals transmitted from the one or more first user terminals or the one or more second user terminals to an optical receiving section.

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