Wavelength-supplying light source device, optical communication system, and wavelength-supplying method

Abstract

This wavelength-supplying light source device comprises: one or more multi-wavelength external light source units capable of outputting light of a plurality of wavelengths; and one or more single wavelength external light source units capable of outputting light of a single wavelength.　

Description

Wavelength supply light source device, optical communication system, and wavelength supply method

[0001] The present invention relates to a wavelength supply light source device, an optical communication system, and a wavelength supply method.

[0002] Conventionally, optical communication devices have been proposed that are composed of an optical distribution device, an optical distribution device control unit, a wavelength control unit, a terminal control unit, and an electrical processing unit (see, for example, Patent Document 1). The optical communication device described in Patent Document 1 performs electrical processing on optical signals transmitted from subscriber devices only when necessary. On the other hand, the optical communication device does not perform electrical processing when not necessary, and forwards the optical signals transmitted from the subscriber devices to the opposite subscriber device. In this way, compared to conventional optical communication devices that require electrical processing, communication with lower latency is achieved because electrical processing is not required.

[0003] Also, a technology has been proposed in which a station remotely supplies light of an assigned wavelength to a subscriber device, and the subscriber device generates an upstream signal by modulating the light of the supplied wavelength (hereinafter referred to as "remote wavelength supply technology") (see, for example, Non-Patent Document 1). By applying the remote wavelength supply technology as in Non-Patent Document 1 to the optical communication device described in Patent Document 1, it becomes possible to supply an arbitrary wavelength from an external device to the subscriber device, and modulate and transmit the supplied wavelength, as shown in Fig. 8.

[0004] FIG. 8 is a diagram showing an example of the configuration of a conventional optical communication system S. The optical communication system S includes one or more optical distribution devices 2, a WXC unit 3, an electrical processing unit 5, a multi-wavelength light source unit 6, and a control unit 7. One or more subscriber devices 8 are connected to the one or more optical distribution devices 2. In the upstream direction, the optical distribution device 2 receives signals from multiple subscriber devices 8, multiplexes signals with the same destination route, and outputs a multiplexed signal for each route. In the downstream direction, the optical distribution device 2 receives multiplexed signals from multiple routes and outputs the required signals to each subscriber device 8. Note that in Patent Document 1, the optical distribution device 2 is composed of an optical SW and an AWG (Arrayed Waveguide Grating). In Patent Document 1, wavelength multiplexing and demultiplexing are performed by the AWG, and input / output destination switching according to the route is performed by the optical SW.

[0005] The WXC unit 3 is composed of a wavelength multiplexer / demultiplexer 4 for each path, and the wavelength multiplexer / demultiplexer 4 is, for example, a WSS (Wavelength Selective Switch). In the upstream direction, the wavelength multiplexer / demultiplexer 4 multiplexes signals output from the optical distribution device 2 and outputs them to the path side, and in the downstream direction, it outputs a wavelength-multiplexed signal input from the path side to the optical distribution device 2 that accommodates the subscriber device 8 that is the destination of that wavelength. The electrical processing unit 5 processes the optical signal transmitted from the subscriber device 8 in the electrical domain as necessary.

[0006] The subscriber device 8 has an optical transceiver. The optical transceiver is a wavelength-tunable optical transmitter / receiver that can communicate at any wavelength. The optical transceiver may be an optical transceiver with an AMCC (Auxiliary Management and Control Channel) function, in which case the wavelength used can be controlled via a control signal superimposed by the AMCC. The control unit 7 controls the optical distribution device 2 and the multi-wavelength light source unit 6. In this way, by arranging the multi-wavelength light source unit 6 inside the optical communication device 1 and centralizing wavelength management, it is possible to simplify wavelength control for the subscriber device 8. The subscriber devices 8 may be geographically distributed, or multiple subscriber devices 8 may be located within the same base.

[0007] International Publication No. 2021 / 131001

[0008] Wooram Lee, “Bidirectional WDM-PON based on gain-saturated reflective semiconductor optical amplifiers”, 2005 IEEE.

[0009] In the configuration shown in Figure 8, possible patterns of optical paths opened between any subscriber devices 8 include a pattern in which the path is shared with other optical paths, and a pattern in which the path is not shared with other optical paths. The pattern in which the path is shared with other optical paths corresponds to, for example, an optical path passing through a core or metro section. In Figure 8, the pattern in which the path is shared with other optical paths corresponds to an optical path output from subscriber device 8-3 and directed to path 2 via the optical distribution device 9, optical distribution device 2, and wavelength multiplexing / demultiplexing unit 4. Note that path 1 and path 2 are core or metro sections. In the case of a pattern in which the path is shared with other optical paths, each subscriber device 8 needs to use a wavelength specified in the Dense Wavelength Division Multiplexing (DWDM) standard.

[0010] On the other hand, a pattern that does not share a route with other optical paths corresponds to, for example, an optical path that does not pass through a core or metro section. Examples of optical paths that do not pass through a core or metro section include an "optical path that is looped back and connected by an optical communication device," an "optical path heading to an electrical processing unit," and an "optical path between subscriber devices in the same base." In Fig. 8, an "optical path that is looped back and connected by an optical communication device" corresponds to an optical path that is output from subscriber device 8-1, looped back by optical distribution device 2 provided in optical communication device 1, and headed toward subscriber device 8-2.

[0011] 8, the "optical path heading to the electrical processing unit" corresponds to the optical path output from subscriber device 8-2 and heading to the optical distribution device 2 and electrical processing unit 5. In Fig. 8, the "optical path between subscriber devices at the same base" corresponds to the optical path output from subscriber device 8-3, turned back by the optical distribution device 9, and heading to subscriber device 8-4 accommodated at the same base.

[0012] As described above, the optical paths that the subscriber device 8 requests to open have different uses. Therefore, there is a problem that it is inefficient to realize optical paths for different uses using one multi-wavelength light source unit 6, as in the past. For example, when starting communication with a pattern that shares a route with other optical paths, if a large number of DWDM wavelengths have already been used for communication with a pattern that does not share a route with other optical paths, it may not be possible to open the optical path.

[0013] In view of the above circumstances, an object of the present invention is to provide a technique that can efficiently allocate wavelengths according to the purpose of opening an optical path.

[0014] One aspect of the present invention is a wavelength supply light source device that includes one or more multi-wavelength external light source units that output light of multiple wavelengths, and one or more single-wavelength external light source units that output light of a single wavelength.

[0015] One aspect of the present invention is an optical communications system comprising: a control unit that receives a control signal including a request to open an optical path transmitted from one or more subscriber devices requesting the opening of an optical path; and a wavelength supply light source device that supplies a specific wavelength to the one or more subscriber devices in response to an instruction from the control unit, wherein the wavelength supply light source device comprises one or more multi-wavelength external light source units that output light of multiple wavelengths and one or more single-wavelength external light source units that output light of a single wavelength, and wherein light of a specific wavelength is supplied to the one or more subscriber devices from either the one or more multi-wavelength external light source units or the one or more single-wavelength external light source units in response to an instruction from the control unit.

[0016] One aspect of the present invention is a wavelength supply method that supplies light of a specific wavelength to one or more subscriber devices requesting the opening of an optical path from either a multi-wavelength external light source unit that outputs light of multiple wavelengths, or a single-wavelength external light source unit that outputs light of a single wavelength, depending on the purpose of the optical path used by the one or more subscriber devices requesting the opening of an optical path.

[0017] According to the present invention, it becomes possible to efficiently allocate wavelengths according to the purpose for which an optical path is opened.

[0018] FIG. 1 is a diagram illustrating a configuration example of an optical communication system according to a first embodiment. FIG. 2 is a diagram illustrating a configuration example of a multi-wavelength light source unit according to the first embodiment. FIG. 3 is a diagram illustrating another example of a multi-wavelength external light source unit according to the first embodiment. FIG. 4 is a sequence diagram illustrating a flow (part 1) of an optical path opening process performed by the optical communication system according to the first embodiment. FIG. 5 is a sequence diagram illustrating a flow (part 2) of an optical path opening process performed by the optical communication system according to the first embodiment. FIG. 6 is a diagram illustrating a configuration example of an optical communication system according to a second embodiment. FIG. 7 is a diagram illustrating a configuration example of an optical communication system according to a third embodiment. FIG. 8 is a diagram illustrating a configuration example of a conventional optical communication system.

[0019] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0020] 1 is a diagram showing an example of the configuration of an optical communication system 100 according to a first embodiment. The optical communication system 100 includes an optical communication device 10, a control unit 15, and an optical distribution device 80. The optical communication device 10 includes one or more optical distribution devices 20, a WXC unit 30, an electrical processing unit 50, and a multi-wavelength light source unit 60.

[0021] One or more optical distribution devices 20 are connected to one or more subscriber devices 75 directly or via an optical distribution device 80. In the following explanation, as an example, a case where there is one optical distribution device 20, 80 and four subscriber devices 75 will be explained. Subscriber devices 75-1 and 75-2 are accommodated at different bases. Subscriber devices 75-3 and 75-4 are accommodated at the same base.

[0022] Optical transmission paths are used to connect the control unit 15 and the light distribution device 20, between the light distribution device 20 and the WXC unit 30, between the light distribution device 20 and the electrical processing unit 50, between the multi-wavelength light source unit 60 and the subscriber device 75, and between the multi-wavelength light source unit 60 and the light distribution device 80. The optical transmission paths are, for example, optical fibers. Note that, between the control unit 15 and the light distribution device 20, between the control unit 15 and the WXC unit 30, between the control unit 15 and the multi-wavelength light source unit 60, and between the control unit 15 and the light distribution device 80, electric wires may be connected to perform control using electric signals from the control unit 15 to the light distribution device 20, the WXC unit 30, the multi-wavelength light source unit 60, or the light distribution device 80.

[0023] As shown in FIG. 1 , the optical distribution device 80 is provided at a base station that accommodates the subscriber devices 75-3 and 75-4. Control signals are transmitted and received between the control unit 15 and each subscriber device 75. The control signals transmitted from the control unit 15 to each subscriber device 75 are signals for controlling the subscriber device 75, and include, for example, an optical path opening permission. The control signals transmitted from each subscriber device 75 to the control unit 15 include requests to the control unit 15, such as an optical path opening request. The optical path opening request includes information indicating the communication partner. Therefore, the control unit 15 can identify the communication partner of each subscriber device 75 based on the control signals transmitted from each subscriber device 75, including an optical path opening permission. The main signal and control signal transmitted and received by the subscriber device 75 may have the same wavelength or different wavelengths. Note that if the main signal and control signal have the same wavelength, the subscriber device 75 may use an auxiliary management and control channel (AMCC), which superimposes the control signal in a low-frequency region.

[0024] The optical distribution device 20 has a plurality of first ports and a plurality of second ports. An optical signal input to a certain port of the optical distribution device 20 is output from another port. For example, an optical signal input to the first port of the optical distribution device 20 is output from the second port. In the following description, as an example, it is assumed that one or more subscriber devices 75 or optical distribution devices 80 are connected to the first port of the optical distribution device 20, and that the control unit 15 and the WXC unit 30 are connected to the second port of the optical distribution device 20.

[0025] Furthermore, it is assumed that a first port of the optical distribution device 20 is connected to a first port of the electrical processing unit 50, and a second port of the optical distribution device 20 is connected to a second port of the electrical processing unit 50. As the optical distribution device 20, for example, an optical switch or a wavelength selective cross connect (WXC) is used.

[0026] In the optical distribution device 20, an optical detector or a WDM (Wavelength Division Multiplexing) filter may be provided between the port (e.g., the first port) to which the subscriber device 75 is connected and the subscriber device 75. An optical detector is provided for each port (e.g., the first port) to which the subscriber device 75 is connected. The optical detector detects an optical signal input to a port of the optical distribution device 20. The optical detector is, for example, a power monitor. When the optical detector detects an optical signal, it notifies the optical distribution device 20 that an optical signal has been detected. The optical distribution device 20 notifies the control unit 15 of information indicating which port the optical detector installed at which it received the notification. This allows the control unit 15 to determine which port of the optical distribution device 20 the subscriber device 75 is connected to.

[0027] The WDM filter multiplexes or separates optical signals of different wavelengths. For example, the WDM filter separates a main signal and a control signal transmitted from the subscriber device 75. When the optical distribution device 20 is an optical switch, the WDM filter is provided between the optical distribution device 20 and the subscriber device 75.

[0028] In the upstream direction, the WXC unit 30 multiplexes signals from the optical distribution device 20 and outputs them to the destination path side, and in the downstream direction, it outputs wavelength-multiplexed signals input from the path side to the optical distribution device 20 that accommodates the subscriber device 75 that is the destination of that wavelength. Also, if the wavelength-multiplexed signal input from the path side is a wavelength destined for a subscriber device at another base, the WXC unit 30 outputs it to a port connected to the wavelength multiplexing / demultiplexing unit of the path toward that base. Paths 1 and 2 in Figure 1 are core or metro sections.

[0029] The WXC unit 30 is composed of a wavelength multiplexing / demultiplexing unit 40 for each path. The wavelength multiplexing / demultiplexing unit 40 multiplexes or demultiplexes input optical signals according to their wavelengths. For example, the wavelength multiplexing / demultiplexing unit 40 multiplexes optical signals of multiple wavelengths output from one or more optical distribution devices 20 to generate a multiplexed signal. The wavelength multiplexing / demultiplexing unit 40 outputs the generated multiplexed signal in the direction of the transmission path. For example, the wavelength multiplexing / demultiplexing unit 40 demultiplexes a multiplexed signal input from the transmission path direction by wavelength and outputs it. The wavelength multiplexing / demultiplexing unit 40 is, for example, an AWG or a WSS.

[0030] The electrical processing unit 50 converts optical signals into electrical signals, performs electrical processing, and then converts the signals back into optical signals for output. The electrical processing unit 50 includes an O / E converter, a processing execution unit, and an E / O converter. The O / E converter converts optical signals output from the optical distribution device 20 into electrical signals. The processing execution unit performs electrical processing on the electrical signals converted by the O / E converter by having a processor such as a central processing unit (CPU) read and execute a program from a storage unit (not shown). This electrical processing includes electrical signal processing functions and optical line terminal (OLT) functions. The signal processing function is, for example, code error correction such as forward error correction (FEC). The E / O converter converts electrical signals into optical signals and outputs them to the optical distribution device 20. The O / E converter and E / O converter are, for example, tunable transceivers.

[0031] The multi-wavelength light source unit 60 is a light source capable of outputting light of any wavelength from each port. In this embodiment, the multi-wavelength light source unit 60 includes a light source capable of outputting light of any wavelength from among a plurality of wavelengths (hereinafter referred to as a "multi-wavelength external light source unit"), and a light source capable of outputting light of a single wavelength (hereinafter referred to as a "single-wavelength external light source unit"). The multi-wavelength light source unit 60 outputs light of a specific wavelength using a light source in accordance with instructions from the control unit 15. In this way, the multi-wavelength light source unit 60 supplies light of a specific wavelength to a subscriber device 75 that wishes to open an optical path. The multi-wavelength light source unit 60 is one aspect of a wavelength supply light source device.

[0032] The control unit 15 controls at least the optical distribution devices 20 and 80, the multi-wavelength light source unit 60, and the subscriber device 75. Here, controlling the optical distribution devices 20 and 80 includes, for example, switching the connections between the ports of the optical distribution devices 20 and 80 and setting the transmission wavelengths. For example, if the wavelengths of the main signal and the control signal are different and the optical distribution device 20 is a wavelength selective cross connect, the control unit 15 can output the control signal and the main signal to the desired destination by setting the wavelength for the control signal and the wavelength for the main signal.

[0033] Controlling the multi-wavelength light source unit 60 means, for example, causing a specific light source to output light of a specific wavelength from the multi-wavelength light source unit 60. As described above, the multi-wavelength light source unit 60 is equipped with different light sources. Therefore, the control unit 15 selects a light source that will be the source of light of a specific wavelength depending on the purpose of the optical path used by the subscriber device 75 that requests the opening of the optical path.

[0034] For example, if the optical path used by the subscriber device 75 requesting the opening of an optical path is used for communication that shares a route with other optical paths, the control unit 15 selects a multi-wavelength external light source unit as the light source that will be the supply source. On the other hand, if the optical path used by the subscriber device 75 requesting the opening of an optical path is used for communication that does not share a route with other optical paths, the control unit 15 selects a single-wavelength external light source unit as the light source that will be the supply source.

[0035] Here, communication that shares a route with other optical paths means communication that uses the same route as other optical paths through multiplexing or the like. For example, communication that shares a route with other optical paths is communication that uses an optical path that passes through a core or metro section. Therefore, communication that shares a route with other optical paths is assumed to be communication via the wavelength multiplexing / demultiplexing unit 40, for example. In FIG. 1, communication that shares a route with other optical paths corresponds to an optical path that is output from subscriber device 75-3 and heads toward path 2 via optical distribution device 80, optical distribution device 20, and wavelength multiplexing / demultiplexing unit 40. Note that this is just one example, and any optical path that heads toward at least one of the paths corresponds to communication that shares a route with other optical paths.

[0036] Furthermore, communication that does not share a route with other optical paths means communication that does not use the same route as other optical paths. For example, communication that does not share a route with other optical paths means communication that is not multiplexed with other optical paths by multiplexing or the like and uses an independent route. Therefore, communication that does not share a route with other optical paths is assumed to be, for example, communication that does not go through the wavelength multiplexing / demultiplexing unit 40. In Figure 1, communication that does not share a route with other optical paths corresponds to at least the following (1) to (3).

[0037] (1) "Optical path that is looped back and connected by optical communication equipment" (2) "Optical path that goes to the electrical processing unit" (3) "Optical path between subscriber devices within the same site"

[0038] The "optical path looped back and connected at the optical communication device" corresponds to an optical path that is looped back at the optical communication device 10 and heads toward another subscriber device 75 without passing through a wavelength multiplexing / demultiplexing unit. This is intended to communicate with a subscriber device 75 accommodated at another base station. In Figure 1, the "optical path looped back and connected at the optical communication device" corresponds to an optical path that is output from subscriber device 75-1, looped back at the optical distribution device 20, and heads toward subscriber device 75-2.

[0039] The "optical path heading towards the electrical processing unit" corresponds to an optical path heading towards the electrical processing unit 50. This is intended to cause the electrical processing unit 50 to perform signal processing through electrical processing. In FIG. 1, the "optical path heading towards the electrical processing unit" corresponds to an optical path output from the subscriber device 75-2 and heading towards the optical distribution device 20 and electrical processing unit 50.

[0040] The "optical path between subscriber devices within the same base" corresponds to an optical path heading to a subscriber device 75 accommodated in the same base. This is intended for communication with another subscriber device 75 accommodated in the same base. In Figure 1, the "optical path between subscriber devices within the same base" corresponds to an optical path output from subscriber device 75-3, turned back by optical distribution device 80, and heading to subscriber device 75-4.

[0041] The control unit 15 causes the selected light source to output light of the wavelength assigned to the subscriber device 75 requesting the opening of an optical path. As a result, the light of the assigned wavelength reaches the subscriber device 75 requesting the opening of an optical path. As a result, the subscriber device 75 requesting the opening of an optical path can open the optical path using the light of the wavelength that has arrived.

[0042] Controlling the subscriber device 75 includes, for example, controlling the timing of transmitting a control signal or issuing an optical shutdown instruction. The control unit 15 includes a terminal control unit, a wavelength control unit, and an optical distribution device control unit. The terminal control unit includes a control signal transceiver and a control signal generation unit. The control signal transceiver transmits control signals to the subscriber device 75 or receives control signals transmitted from the subscriber device 75. A control signal transceiver may be provided for each subscriber device 75, or one control signal transceiver may accommodate control signals for multiple subscriber devices 75. The control signal transceiver receives a control signal including a request to open an optical path from the subscriber device 75.

[0043] The control signal generating unit generates a control signal including a permission to open an optical path in response to receiving a control signal including a request to open an optical path.

[0044] Based on the control signal received by the terminal control unit, the wavelength control unit controls the light source used by the multi-wavelength light source unit 60. When a single-wavelength external light source unit is to be used, the wavelength control unit outputs a control signal to the multi-wavelength light source unit 60, the control signal including information indicating that a single-wavelength external light source unit is to be used and information indicating the subscriber device 75 to which power is to be supplied.

[0045] When a multi-wavelength external light source unit is used, the wavelength control unit controls the wavelengths and bandwidths used by the subscriber device 75 for transmission and reception. The wavelength control unit maintains a management table in which wavelengths assigned to the subscriber device 75 correspond to information on bandwidths. The wavelength control unit determines the wavelengths and bandwidths to be assigned to the subscriber device 75 based on the current bandwidth usage status registered in the management table. For example, the wavelength control unit sets wavelength intervals at intervals (fixed) that assume the maximum possible bandwidth for the main signal. The wavelength control unit outputs a control signal to the multi-wavelength light source unit 60, the control signal including information indicating the use of a multi-wavelength external light source unit, information indicating the subscriber device 75 to be supplied with the signal, and information on the determined center wavelength.

[0046] The light distribution device control unit controls the light distribution device 20. The light distribution device control unit performs, for example, any of setting the connection between ports of the light distribution device 20, switching the connection, setting the optical path, and setting the transmission wavelength.

[0047] The subscriber device 75 communicates with the other subscriber device using light of the wavelengths supplied from the multi-wavelength light source unit 60. The subscriber device includes a control signal transceiver unit, a control unit, and a main signal transceiver unit. The control signal transceiver unit transmits and receives control signals to the control unit 15. The control signal transceiver unit transmits a control signal including, for example, a request to open an optical path to the control unit 15. The control signal transceiver unit receives a control signal including, for example, permission to open an optical path from the control unit 15. The control signal transceiver unit outputs the received control signal to the control unit.

[0048] The control unit controls each functional unit of the subscriber device 75. For example, in response to an external request, the control unit causes the control signal transceiver unit to transmit a control signal including a request to open an optical path. For example, after receiving permission to open an optical path included in the control signal output from the control signal transceiver unit, the control unit causes the main signal transceiver unit to transmit a main signal.

[0049] The main signal transceiver transmits and receives a main signal based on instructions from the control unit. For example, in response to instructions from the control unit, the main signal transceiver generates an optical signal containing the data to be transmitted by modulating light of a wavelength supplied from the multi-wavelength light source unit 60 with the data to be transmitted. The main signal transceiver outputs the generated optical signal to the optical transmission path. In this way, the subscriber device 75 realizes communication using light of a specific wavelength supplied from an external source.

[0050] 2 is a diagram showing an example of the configuration of the multi-wavelength light source unit 60 in the first embodiment. The multi-wavelength light source unit 60 is made up of a multi-wavelength external light source unit 61, a single-wavelength external light source unit 62, and a light distribution device 63.

[0051] The multi-wavelength external light source unit 61 is a light source capable of outputting light of multiple wavelengths. The multi-wavelength external light source unit 61 is, for example, a light source that has multiple ports and can output DWDM wavelengths from each port. The multi-wavelength external light source unit 61 may be, for example, a configuration in which multiple tunable lasers are arranged in an array, a configuration in which multiple single-wavelength lasers are arranged in an array, or a configuration using an optical comb light source. A single-wavelength laser is a laser that can output light of a specific wavelength.

[0052] 2 shows an example in which the multi-wavelength external light source unit 61 is composed of N (N is an integer of 2 or more) single-wavelength light sources 65-1 to 65-N. Each of the N single-wavelength light sources 65-1 to 65-N outputs light of a different single wavelength. For example, the single-wavelength light source 65-1 outputs light of a wavelength λ １ The single wavelength light source 65-N outputs a wavelength of light λ Ｎ The multi-wavelength external light source unit 61 includes a control unit (not shown), and controls each single-wavelength light source 65 to output light of one or more wavelengths under the control of the control unit (not shown).

[0053] The single-wavelength external light source unit 62 is a light source capable of outputting light of a single wavelength. The single-wavelength external light source unit 62 is composed of a single-wavelength light source 66 and a branching unit 67. The single-wavelength light source 66 outputs light of a single wavelength. The wavelength of the single-wavelength light source 66 may be any wavelength, including a non-DWDM wavelength. A non-DWDM wavelength is a wavelength that is not included in the DWDM wavelengths (for example, a wavelength included in the O band, E band, or S band). The branching unit 67 branches and outputs light of a wavelength output from the single-wavelength light source 66. For example, an optical coupler or the like is used as the branching unit 67. The single-wavelength external light source unit 62 is equipped with a control unit (not shown), and causes the single-wavelength light source 66 to output light of a single wavelength under the control of the control unit (not shown).

[0054] As described above, either the multi-wavelength external light source unit 61 or the single-wavelength external light source unit 62 included in the multi-wavelength light source unit 60 outputs light of one or more wavelengths.

[0055] The optical distribution device 63 outputs an optical signal input to any port from any port. The optical distribution device 63 switches the connection between ports under the control of the control unit 15, and outputs light of the wavelength output from the multi-wavelength external light source unit 61 or the single-wavelength external light source unit 62 from the port to which the target subscriber device 75 is connected.

[0056] 3 is a diagram showing another example of the multi-wavelength external light source unit 61 in the first embodiment. The multi-wavelength external light source unit 61 is composed of an optical comb light source 68 and a wavelength demultiplexer 69. The optical comb light source 68 collectively generates light of different wavelengths spaced apart by a central wavelength and outputs the collectively generated light of different wavelengths as a wavelength multiplexed signal. The wavelength demultiplexer 69 outputs light of a specific wavelength from the wavelength multiplexed signal output from the optical comb light source 68 in accordance with settings from the control unit 15. The wavelength demultiplexer 69 is, for example, an AWG or a WSS.

[0057] 4 is a sequence diagram showing the flow (part 1) of the optical path opening process performed by the optical communication system 100 in the first embodiment. Note that the process in FIG. 4 will be described with reference to FIG. 1 assuming that the optical path used by the subscriber device 75 requesting the opening of the optical path is used for communication that shares a route with other optical paths. Here, the case where the subscriber device 75 requesting the opening of the optical path is subscriber device 75-3 will be described as an example.

[0058] The control signal transmitting / receiving unit of the subscriber device 75-3 generates a control signal including a request to open an optical path. At this time, the subscriber device 75-3 includes in the optical path opening request information indicating that it will communicate with another subscriber device located on direction 2. The control signal transmitting / receiving unit transmits the generated control signal including the optical path opening request (step S101). The control signal transmitted from the subscriber device 75-3 is input to a first port of the optical distribution device 20 via the optical transmission path. The control signal input to the first port of the optical distribution device 20 is output from a second port of the optical distribution device 20 to which the control unit 15 is connected.

[0059] The terminal control unit of the control unit 15 receives the control signal output from the optical distribution device 20. The terminal control unit acquires the optical path opening request included in the received control signal. The terminal control unit outputs the acquired optical path opening request to the wavelength control unit. The wavelength control unit determines the light source to be used in accordance with the optical path opening request (step S102). For example, the wavelength control unit determines the light source to be used in accordance with the purpose of the optical path used by the subscriber device 75-3, which is the sender of the optical path opening request. In this case, the purpose of the optical path used by the subscriber device 75-3, which is the sender of the optical path opening request, is for communication that shares a route with other optical paths. In this case, the wavelength control unit determines to use the multi-wavelength external light source unit 61.

[0060] The wavelength control unit refers to the management table and determines the center wavelength to be assigned to the subscriber device 75 (hereinafter referred to as the "opening request subscriber device") that is the sender of the optical path opening request. The wavelength control unit registers the determined center wavelength and bandwidth information in the management table in association with the identification information of the subscriber device 75-3. Here, the bandwidth is the maximum possible bandwidth for the main signal. The wavelength control unit outputs a control signal including information on the determined center wavelength to the optical distribution device control unit.

[0061] The optical distribution device control unit controls the optical distribution device 20 based on the information on the center wavelength included in the control signal output from the wavelength control unit (step S103). Specifically, the optical distribution device control unit performs setting between ports so as to form an optical path connecting the first port of the optical distribution device 20 to which the opening requesting subscriber device is connected and the second port of the optical distribution device 20 to which the subscriber device with which communication is to be performed is connected.

[0062] The first port of the optical distribution device 20 to which the activation-requesting subscriber device is connected may be identified based on the detection result of the optical detector provided between the optical distribution device 20 and the subscriber device 75-3, as described above. This makes it possible to form an optical path between the activation-requesting subscriber device and the subscriber device with which it communicates.

[0063] After the process of step S103, the wavelength control unit outputs a control signal to the multi-wavelength light source unit 60, which signal includes information indicating the use of the multi-wavelength external light source unit 61, information indicating the subscriber unit 75-3 to be supplied with light, and information on the determined center wavelength (step S104). The multi-wavelength light source unit 60 determines the use of the multi-wavelength external light source unit 61 based on the information indicating the use of the multi-wavelength external light source unit 61, which is included in the control signal output from the wavelength control unit. Furthermore, the multi-wavelength light source unit 60 determines the wavelength to be supplied to the subscriber unit 75-3 based on the information on the center wavelength included in the control signal. For example, the multi-wavelength light source unit 60 determines the wavelength λ as the wavelength to be supplied to the subscriber unit 75-3. ３ Furthermore, the multi-wavelength light source unit 60 controls the light distribution device 63 in response to an instruction from the control unit 15 to determine the determined wavelength λ ３The optical distribution device 63 is set so that the light of the above signal is output to the target subscriber device 75-3.

[0064] The multi-wavelength external light source unit 61 receives light of wavelength λ from each of the single-wavelength light sources 65-1 to 65-N. １ ~λ Ｎ The light having a wavelength λ output from the multi-wavelength external light source unit 61 is output (step S105). The light having a wavelength specified by the central wavelength information is light having a wavelength having a central wavelength specified by the central wavelength information. １ ~λ Ｎ The light of wavelength λ is input to the light distribution device 63. １ ~λ Ｎ Of the light of the set wavelength λ ３ For example, if the optical distribution device 63 is an optical switch, the optical distribution device 63 outputs the light of wavelength λ ３ The port connected to the single wavelength light source 65-3 outputting light of wavelength λ 1 is connected to the port connected to the subscriber device 75-3. ３ The light is input to the subscriber device 75-3, which is the opening request subscriber device, via the optical transmission line.

[0065] The main signal transmitting / receiving unit of the subscriber device requesting the opening receives the input wavelength λ ３ The modulated wavelength λ output from the subscriber device requesting activation is ３The light is input to the first port of the optical distribution device 20. The optical signal input to the first port of the optical distribution device 20 is output from the second port. In the processing of step S103, the ports are set so that an optical path can be formed between the first port of the optical distribution device 20 to which the establishment requesting subscriber device is connected and the second port of the optical distribution device 20 to which the communication partner subscriber device is connected. As a result, the optical signal input to the first port of the optical distribution device 20 is output from the second port of the optical distribution device 20 to which the communication partner subscriber device is connected. The optical signal output from the second port of the optical distribution device 20 is input to the wavelength multiplexing / demultiplexing unit 40 to which the communication partner subscriber device is connected. In this way, an optical path is opened between the establishment requesting subscriber device and the communication partner subscriber device (step S106).

[0066] When the optical distribution device 20 completes the setting of the connection between the ports, it transmits a setting completion notification indicating the completion of the setting to the control unit 15. When the terminal control unit of the control unit 15 receives the setting completion notification from the optical distribution device 20, it generates a control signal including an opening permission. The terminal control unit transmits the control signal including the opening permission to the opening request subscriber device (step S107). The control signal transmitted from the terminal control unit is input to the opening request subscriber device via the optical transmission path. The control signal transmitting / receiving unit of the opening request subscriber device receives the input control signal. The control signal transmitting / receiving unit outputs the opening permission included in the received control signal to the control unit. The control unit becomes ready for communication in response to the opening permission output from the control signal transmitting / receiving unit.

[0067] When the subscriber device that requests the connection to be established performs communication, the control unit instructs the main signal transmitting / receiving unit to transmit the data to be transmitted. In response to the instruction from the control unit, the main signal transmitting / receiving unit transmits the data at the wavelength λ ３ The optical signal transmitting / receiving unit outputs the generated optical signal to the optical transmission path (step S108). As a result, the optical signal output from the access requesting subscriber device reaches the subscriber device with which the communication is to be performed via the optical path.

[0068] 5 is a sequence diagram showing the flow (part 2) of the optical path opening process performed by the optical communication system 100 in the first embodiment. Note that the process in FIG. 5 will be described assuming that the optical path used by the subscriber device 75 requesting the opening of the optical path is used for communication that does not share a route with other optical paths.

[0069] The control signal transmitting / receiving unit of the subscriber device 75 generates a control signal including a request to open an optical path. The control signal transmitting / receiving unit transmits the generated control signal including the request to open an optical path (step S201). The control signal transmitted from the subscriber device 75 is input to a first port of the optical distribution device 20 via an optical transmission path. The control signal input to the first port of the optical distribution device 20 is output from a second port of the optical distribution device 20 to which the control unit 15 is connected.

[0070] The terminal control unit of the control unit 15 receives the control signal output from the optical distribution device 20. The terminal control unit acquires the optical path opening request included in the received control signal. The terminal control unit outputs the acquired optical path opening request to the wavelength control unit. The wavelength control unit determines the light source to be used in accordance with the optical path opening request (step S202). For example, the wavelength control unit determines the light source to be used in accordance with the purpose of the optical path used by the subscriber device 75 that is the sender of the optical path opening request. Here, it is assumed that the purpose of the optical path used by the subscriber device 75 that is the sender of the optical path opening request is for communication that does not share a route with other optical paths. In this case, the wavelength control unit determines to use the single-wavelength external light source unit 62.

[0071] The optical distribution device control unit controls the optical distribution device 20 or 80 depending on the application for communication that does not share a route with other optical paths (step S203). In the case where the opening requesting subscriber device is the subscriber device 75-1 and an optical path for return communication from the subscriber device 75-1 to the subscriber device 75-2 is to be opened, the optical distribution device control unit performs port settings so as to form an optical path connecting the first port of the optical distribution device 20 to which the subscriber device 75-1 is connected and the first port of the optical distribution device 20 to which the communication partner subscriber device (e.g., the subscriber device 75-2) is connected.

[0072] In the case where the subscriber device requesting the opening is subscriber device 75-2 and the pattern is to open an optical path for communication from subscriber device 75-2 to the electrical processing unit 50, the optical distribution device control unit configures the ports so that an optical path can be formed connecting the first port of the optical distribution device 20 to which subscriber device 75-2 is connected and the second port of the optical distribution device 20 to which the electrical processing unit 50 is connected.

[0073] In the case where the subscriber device requesting the opening is subscriber device 75-3 and an optical path for intra-site communication from subscriber device 75-3 to subscriber device 75-4 is to be opened, the optical distribution device control unit configures the ports so that an optical path can be formed connecting the port of the optical distribution device 80 to which subscriber device 75-3 is connected and the port of the optical distribution device 80 to which subscriber device 75-4 is connected.

[0074] After the processing of step S203, the wavelength control unit outputs information indicating the use of the single-wavelength external light source unit 62 and information indicating the subscriber device 75 to be supplied to the multi-wavelength light source unit 60 (step S204). The multi-wavelength light source unit 60 determines to use the single-wavelength external light source unit 62 based on the information indicating the use of the single-wavelength external light source unit 62, which is included in the control signal output from the wavelength control unit. The multi-wavelength light source unit 60 controls the light distribution device 63 in response to an instruction from the control unit 15, and sets the light distribution device 63 so that light of the wavelength output from the single-wavelength external light source unit 62 is output to the target subscriber device 75.

[0075] The single-wavelength external light source unit 62 outputs light of a single wavelength (step S205). The light of the wavelength output from the single-wavelength external light source unit 62 is input to the optical distribution device 63. The optical distribution device 63 outputs the light of the input wavelength from a port to which the activation request subscriber device is connected. For example, if the optical distribution device 63 is an optical switch, the optical distribution device 63 may connect the single-wavelength external light source unit 62 to a port to which the activation request subscriber device is connected. The light of the wavelength output from the optical distribution device 63 is input to the activation request subscriber device via an optical transmission path.

[0076] The main signal transceiver of the activation requesting subscriber device modulates and outputs the light of the input wavelength. The modulated light of the wavelength output from the activation requesting subscriber device is input to the first port of the optical distribution device 20. The optical signal input to the first port of the optical distribution device 20 is output from the second port. The optical signal input to the first port of the optical distribution device 20 is output from the port of the optical distribution device 20 to which the subscriber device with which it will communicate is connected. The optical signal output from the port of the optical distribution device 20 is input to the subscriber device with which it will communicate. In this way, an optical path is opened between the activation requesting subscriber device and the subscriber device with which it will communicate (step S206).

[0077] When the optical distribution device 20 completes the setting of the connection between the ports, it transmits a setting completion notification indicating the completion of the setting to the control unit 15. When the terminal control unit of the control unit 15 receives the setting completion notification from the optical distribution device 20, it generates a control signal including an opening permission. The terminal control unit transmits the control signal including the opening permission to the opening request subscriber device (step S207). The control signal transmitted from the terminal control unit is input to the opening request subscriber device via the optical transmission path. The control signal transmitting / receiving unit of the opening request subscriber device receives the input control signal. The control signal transmitting / receiving unit outputs the opening permission included in the received control signal to the control unit. The control unit becomes ready for communication in response to the opening permission output from the control signal transmitting / receiving unit.

[0078] When the activation requesting subscriber device is to communicate, the control unit instructs the main signal transceiver unit to transmit the data to be transmitted. In response to the control unit's instruction, the main signal transceiver unit generates an optical signal containing the data to be transmitted by modulating the light of the wavelength supplied from the multi-wavelength light source unit 60 with the data to be transmitted. The main signal transceiver unit outputs the generated optical signal to the optical transmission path (step S208). As a result, the optical signal output from the activation requesting subscriber device reaches the subscriber device with which it is to communicate via the optical path.

[0079] In the optical communication system 100 configured as described above, the multi-wavelength light source unit 60 includes a multi-wavelength external light source unit 61 that outputs light of multiple wavelengths and a single-wavelength external light source unit 62 that outputs light of a single wavelength. The multi-wavelength light source unit 60 supplies light of a specific wavelength to the subscriber device 75 from either the multi-wavelength external light source unit 61 or the single-wavelength external light source unit 62 in response to an instruction from the control unit 15. In this manner, the multi-wavelength light source unit 60 switches between the multi-wavelength external light source unit 61 and the single-wavelength external light source unit 62 in response to an instruction from the control unit 15 to supply light of a specific wavelength to the subscriber device 75. This allows the multi-wavelength external light source unit 60 to assign a wavelength from the multi-wavelength external light source unit 61 that is different from the wavelengths used in the other optical paths when used for communication that shares a route with other optical paths, and to assign a single wavelength output by the single-wavelength external light source unit 62 when used for communication that does not share a route with other optical paths. This enables efficient wavelength assignment according to the purpose of opening an optical path.

[0080] Furthermore, in the optical communication system 100, when used for communication that does not share a route with other optical paths, it is possible to reduce light source costs by branching light of a single wavelength. Furthermore, when communication that does not share a route with other optical paths is performed, the wavelength to be used is fixed, and wavelengths can be quickly assigned regardless of the wavelength usage status of communications that share a route with other optical paths, thereby simplifying wavelength control.

[0081] Second Embodiment As in the first embodiment, the optical transmission paths connecting the subscriber devices and the optical communication devices may be prepared in the number corresponding to the number of passing signals or wavelengths as shown in Fig. 1, but it is expected that the number of optical fibers will be large. A configuration that reduces the number of optical fibers is desirable from the viewpoint of fiber costs. Therefore, in the second embodiment, a configuration will be described in which the optical communication devices and base stations are connected by multiple wavelength multiplexing / demultiplexing units and the access fiber sections are wavelength-multiplexed to reduce the number of optical fibers.

[0082] 6 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 an optical communication device 10a, a control unit 15a, an optical distribution device 80, a wavelength multiplexing / demultiplexing unit 85, and a branching unit 90. The optical communication device 10a also includes one or more optical distribution devices 20, a WXC unit 30, an electrical processing unit 50, a multi-wavelength light source unit 60, and a wavelength multiplexing / demultiplexing unit 86.

[0083] As shown in FIG. 6, a wavelength multiplexer / demultiplexer 85 and a wavelength multiplexer / demultiplexer 86 are provided in the access fiber section between the optical communication device 10 a and the subscriber device 75 .

[0084] Optical transmission paths are used to connect the control unit 15a and the optical distribution device 20, between the optical distribution device 20 and the WXC unit 30, between the optical distribution device 20 and the electrical processing unit 50, between the multi-wavelength light source unit 60 and the subscriber device 75, between the multi-wavelength light source unit 60 and the wavelength multiplexing / demultiplexing unit 86, between the wavelength multiplexing / demultiplexing unit 85 and the wavelength multiplexing / demultiplexing unit 86, between the wavelength multiplexing / demultiplexing unit 85 and the optical distribution device 80, and between the wavelength multiplexing / demultiplexing unit 85 and the branching unit 90. The optical transmission paths are, for example, optical fibers. Note that, between the control unit 15a and the optical distribution device 20, between the control unit 15a and the WXC unit 30, between the control unit 15a and the multi-wavelength light source unit 60, and between the control unit 15a and the optical distribution device 80, electric wires may be connected to perform control using electric signals from the control unit 15a to the optical distribution device 20, the WXC unit 30, the multi-wavelength light source unit 60, or the optical distribution device 80.

[0085] The control unit 15 a controls at least the optical distribution devices 20 and 80 , the multi-wavelength light source unit 60 , and the subscriber device 75 .

[0086] The wavelength multiplexing / demultiplexing unit 85 is provided, for example, at a base station. The wavelength multiplexing / demultiplexing unit 85 multiplexes or demultiplexes input optical signals. The wavelength multiplexing / demultiplexing unit 85 multiplexes optical signals of different wavelengths output from multiple subscriber devices 75 in the upstream direction, and demultiplexes a wavelength-multiplexed signal output from the optical communication device 10 a in the downstream direction.

[0087] The wavelength multiplexing / demultiplexing unit 86 is provided, for example, inside the optical communication device 10 a. The wavelength multiplexing / demultiplexing unit 86 demultiplexes wavelength-multiplexed signals in the upstream direction, and multiplexes optical signals of different wavelengths output from the multi-wavelength light source unit 60 or optical signals of different wavelengths output from the optical distribution device 20 in the downstream direction.

[0088] The branching unit 90 is connected to a port of the wavelength multiplexing / demultiplexing unit 85 and branches the light of the wavelengths separated by the wavelength multiplexing / demultiplexing unit 85. The branching unit 90 outputs the branched light of the wavelengths to the multiple subscriber devices 75 connected thereto. When wavelength multiplexing / demultiplexing units 85, 86 are provided in the access fiber section, only one wavelength from the single-wavelength external light source unit 62 can be sent per fiber at the base. Therefore, by providing a branching unit 90 within the base as shown in FIG. 6, the number of single-wavelength fibers can be increased.

[0089] The locations of the wavelength multiplexing / demultiplexing units 85 and 86 are not limited to the configuration shown in Fig. 6. For example, the wavelength multiplexing / demultiplexing units 85 and 86 may be provided between the optical communication device 10a and the subscriber devices 75-1 and 75-2.

[0090] According to the optical communication system 100a configured as above, it is possible to obtain the same effects as those of the first embodiment.

[0091] Furthermore, in the optical communication system 100a, a wavelength multiplexing / demultiplexing unit that performs wavelength multiplexing or wavelength demultiplexing is provided in the access fiber section. This makes it possible to reduce the number of optical fibers used in the access fiber section, thereby making it possible to reduce fiber costs.

[0092] Third Embodiment In each of the above-described embodiments, when a single base station accommodates a large number of subscriber devices, or when there are multiple base stations and each base station accommodates multiple subscriber devices, it is difficult from a budget perspective to supply wavelengths to each of the subscriber devices accommodated at each base station from a single optical communication device. Therefore, it is considered effective to provide a separate multi-wavelength light source unit within a base station that accommodates multiple subscriber devices. Therefore, in the third embodiment, a configuration is described in which a supply source (e.g., a multi-wavelength light source unit) that supplies light of a specific wavelength to the subscriber devices is provided separately within the base station in addition to the optical communication device. Note that the supply source installed within the base station may be only a multi-wavelength external light source unit, only a single-wavelength external light source unit, or both a multi-wavelength external light source unit and a single-wavelength external light source unit. In the third embodiment, a case in which a single-wavelength external light source unit is provided at the base station is described as an example.

[0093] 7 is a diagram showing an example of the configuration of an optical communication system 100b according to the third embodiment. The optical communication system 100b includes an optical communication device 10a, a control unit 15b, an optical distribution device 80, a wavelength multiplexing / demultiplexing unit 85, and a single-wavelength external light source unit 95. The optical communication device 10a includes one or more optical distribution devices 20, a WXC unit 30, an electrical processing unit 50, a multi-wavelength light source unit 60, and a wavelength multiplexing / demultiplexing unit 86.

[0094] The optical communication system 100b differs from the optical communication system 100a in that it includes a control unit 15b instead of the control unit 15a, does not include a branching unit 90, and is newly provided at a base with a single-wavelength external light source unit 95. Note that the optical communication system 100b may include a branching unit 90, as in the optical communication system 100a. The following description will focus on the differences from the optical communication system 100a.

[0095] The control unit 15b controls at least the optical distribution devices 20 and 80, the multi-wavelength light source unit 60, and the subscriber device 75. If a multi-wavelength light source unit having a configuration similar to that of the multi-wavelength light source unit 60 is provided in the base station, the control unit 15b controls the optical distribution device provided in the multi-wavelength light source unit provided in the base station.

[0096] The single-wavelength external light source unit 95 is a light source capable of outputting light of a single wavelength. The single-wavelength external light source unit 95 has a configuration similar to that of the single-wavelength external light source unit 62. That is, the single-wavelength external light source unit 95 is composed of a single-wavelength light source 66 and a branching unit 67. The single-wavelength light source 66 outputs light of a single wavelength. The branching unit 67 branches the light of the wavelength output from the single-wavelength light source 66 and outputs it.

[0097] According to the optical communication system 100b configured as described above, a light source that serves as a wavelength supply source is also provided at the base station where the subscriber device 75 is accommodated. This eliminates the need to supply wavelengths from the optical communication device 10a to all of the subscriber devices 75. This makes it possible to allocate wavelengths efficiently.

[0098] (Modifications Common to the First to Third Embodiments) In each of the above-described embodiments, the multi-wavelength light source unit 60 is provided inside the optical communication device 10, 10a. However, the installation location of the multi-wavelength light source unit 60 is not limited to this. For example, the multi-wavelength external light source unit 61 and the single-wavelength external light source unit 62 constituting the multi-wavelength light source unit 60 may be provided outside the optical communication device 10, 10a. For example, at least one of the multi-wavelength external light source unit 61 and the single-wavelength external light source unit 62 may be provided outside the optical communication device 10, 10a. Alternatively, the multi-wavelength external light source unit 61 and the single-wavelength external light source unit 62 may be installed at different arbitrary locations (e.g., within a base), or may be installed at multiple arbitrary locations (e.g., both the multi-wavelength external light source unit 61 and the single-wavelength external light source unit 62 within a base different from the optical communication device 10, 10a).

[0099] Alternatively, either the multi-wavelength external light source unit 61 or the single-wavelength external light source unit 62 constituting the multi-wavelength light source unit 60 may be provided in the optical communication device 10, 10a, or either the multi-wavelength external light source unit 61 or the single-wavelength external light source unit 62 may be provided outside the optical communication device 10, 10a. For example, the multi-wavelength external light source unit 61 may be provided in the optical communication device 10, 10a, and the single-wavelength external light source unit 62 may be provided outside the optical communication device 10, 10a (for example, within a base), or the single-wavelength external light source unit 62 may be provided in the optical communication device 10, 10a, and the multi-wavelength external light source unit 61 may be provided outside the optical communication device 10, 10a (for example, within a base). In addition, when either the multi-wavelength external light source unit 61 or the single-wavelength external light source unit 62 is provided in the optical communication device 10, 10a, an optical distribution device 63 is provided at the output destination of the multi-wavelength external light source unit 61 or the single-wavelength external light source unit 62 provided in the optical communication device 10, 10a.

[0100] At least some or all of the functional units of the control units 15, 15a, and 15b, or some or all of the functional units of the subscriber device 75, are realized as software by a processor such as a central processing unit (CPU) executing a program stored in a storage device having a non-volatile storage medium (non-transitory storage medium) and the storage unit. The program may be recorded on a computer-readable non-transitory storage medium. Examples of computer-readable non-transitory storage media include portable media such as flexible disks, magneto-optical disks, read-only memories (ROMs), and compact disc read-only memories (CD-ROMs), and storage devices such as hard disks built into computer systems.

[0101] At least some or all of the functional units of the control units 15, 15a, and 15b, or some or all of the functional units of the subscriber device 75, may be realized using hardware including electronic circuits (electronic circuits or circuitry) using, for example, an LSI (Large Scale Integrated circuit), an ASIC (Application Specific Integrated Circuit), a PLD (Programmable Logic Device), or an FPGA (Field Programmable Gate Array).

[0102] Although an embodiment of the present invention has been described above in detail 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 an optical communication system that performs an optical path opening process.

[0104] 10...optical communication device, 15, 15a, 15b...control unit, 20, 63, 80...optical distribution device, 30...WXC unit, 40, 85, 86...wavelength multiplexing / demultiplexing unit, 50...electrical processing unit, 60...multiplexing light source unit, 61...multiplexing external light source unit, 62, 95...single-wavelength external light source unit, 65, 65-1 to 65-N...single-wavelength light source, 66...single-wavelength light source, 67, 90...branching unit, 68...optical comb light source, 69...wavelength demultiplexing unit, 100, 100a, 100b...optical communication system

Claims

1. A wavelength supply light source device comprising one or more multi-wavelength external light source units that output light of multiple wavelengths, and one or more single-wavelength external light source units that output light of a single wavelength.

2. A wavelength supply light source device as described in claim 1, which supplies light of a specific wavelength to one or more subscriber devices from either one or more multi-wavelength external light source units or one or more single-wavelength external light source units, depending on the purpose of the optical path used by the one or more subscriber devices requesting the opening of an optical path.

3. A wavelength supply light source device as described in claim 2, wherein when the optical path is used for communications that share a route with other optical paths, light of a specific wavelength is supplied from the one or more multi-wavelength external light source units to the one or more subscriber devices.

4. A wavelength supply light source device as described in claim 2, wherein when the optical path is used for communication that does not share a route with other optical paths, light of the single wavelength is supplied from the one or more single-wavelength external light source units to the one or more subscriber devices.

5. A wavelength supply light source device according to claim 1 or 2, wherein at least one of the one or more multi-wavelength external light source units or the one or more single-wavelength external light source units is arranged within a base station that accommodates one or more subscriber devices.

6. An optical communications system comprising: a control unit that receives a control signal including a request to open an optical path transmitted from one or more subscriber devices requesting the opening of an optical path; and a wavelength supply light source device that supplies a specific wavelength to the one or more subscriber devices in response to an instruction from the control unit, wherein the wavelength supply light source device comprises one or more multi-wavelength external light source units that output light of multiple wavelengths and one or more single-wavelength external light source units that output light of a single wavelength, and supplies light of a specific wavelength to the one or more subscriber devices from either the one or more multi-wavelength external light source units or the one or more single-wavelength external light source units in response to an instruction from the control unit.

7. A wavelength supply method that supplies light of a specific wavelength to one or more subscriber devices requesting the opening of an optical path from either a multi-wavelength external light source unit that outputs light of multiple wavelengths, or a single-wavelength external light source unit that outputs light of a single wavelength, depending on the purpose of the optical path used by the one or more subscriber devices requesting the opening of an optical path.

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