JP2005064864A - Transmitter and receiver of wavelength multiplexing optical signal and light wavelength multiplexing communication system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide wavelength multiplexing optical signal transmitter and receiver, and a light wavelength multiplexing communication system capable of handling with both portions corresponding to optical signals with respective wavelengths and faults in a light transmission line by a minimum and inexpensive constitution. <P>SOLUTION: Communication by the use of either the light transmission line 30a or 30b can be realized by utilizing the wavelength multiplexing optical signal transmitter 100 including an optical signal transmission circuit 110 for respectively outputting optical signals with two kinds of wavelengths according to a transmission signal, and a multiplexer 120 for combining and wavelength-multiplexing the optical signals with the two kinds of wavelengths output from the circuit 110 to separate output ports; and the wavelength multiplexing optical signal receiver 200 including a demultiplexer 220 for demultiplexing and outputting the wavelength multiplexing optical signals transmitted via light transmission lines 30a and 30b to output ports differing in each of the two kinds of wavelengths output from the circuit 110, and an optical signal reception circuit 210 for receiving the optical signals with two kinds of wavelengths and outputting a reception signal. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention switches to a backup wavelength when a failure occurs in an optical signal of a certain wavelength among optical signals transmitted by optical wavelength division multiplexing, and switches to a backup optical transmission line when a failure occurs in the optical transmission line. The present invention relates to a wavelength division multiplexing optical signal transmission apparatus, a wavelength division multiplexing optical signal reception apparatus, and an optical wavelength division multiplexing communication system that perform fault recovery.

  A method of multiplexing a plurality of optical signals having different wavelengths and transmitting them through a single optical fiber, that is, wavelength division multiplexing (WDM) transmission method, can greatly increase the transmission capacity. Furthermore, the optical wavelength router having a demultiplexing characteristic of periodic input / output relation is the center, and this is multiplexed by connecting this and a plurality of WDM transmitter / receivers in a star shape with an optical fiber to form a network. In addition, wavelength addressing capable of assigning destination information to each optical signal becomes possible, and a full mesh WDM transmission network can be constructed.

  Here, when high reliability is required for the optical communication system, a plurality of optical signal transmitters, optical signal receivers, and optical transmission lines are prepared, and when a failure occurs, the switch is controlled to control from the active system. The system is configured to switch to the standby system.

  FIG. 1 shows an example of a conventional optical wavelength division multiplexing communication system (see Patent Document 1). In the figure, 10a and 10b are wavelength multiplexed optical signal transmitters, 20a and 20b are wavelength multiplexed optical signal receivers, 30a. 30b are optical transmission lines, and 41 and 42 are switching units.

  The wavelength division multiplexing optical signal transmitters 10a and 10b respectively have four transmission circuits 11a and 11b that output optical signals having wavelengths λ1 to λ4 corresponding to the transmission signals (indicated as T1 to T4 when each circuit is shown separately). ) And multiplexers 12a and 12b that multiplex optical signals of respective wavelengths. The wavelength division multiplexing optical signal receivers 20a and 20b receive four optical signals of wavelengths λ1 to λ4 and output received signals, respectively. Four receiving circuits 21a and 21b (represented by R1 to R4 when each circuit is shown separately) And demultiplexers 22a and 22b for demultiplexing the wavelength-multiplexed optical signal into optical signals having wavelengths λ1 to λ4.

  The wavelength-multiplexed optical signal transmitter 10a and the wavelength-multiplexed optical signal receiver 20a are connected via an optical transmission line 30a, and these constitute an active system, and the wavelength-multiplexed optical signal transmitter 10b and the wavelength-multiplexed optical signal receiver 20b are These are connected via an optical transmission line 30b, and these constitute a standby system.

  In the above configuration, if all the units are all normal, a transmission signal, for example, a transmission signal 51 composed of three signals, is input to the wavelength multiplexing optical signal transmission device 10a via the switch 41, and each transmission circuit 11a (T1 to T3). ) Are respectively converted into optical signals of wavelengths λ1 to λ3, wavelength-multiplexed by the multiplexer 12a, and transmitted to the wavelength-multiplexed optical signal receiver 20a through the optical transmission line 30a. A wavelength multiplexed optical signal composed of optical signals of wavelengths λ1 to λ3 transmitted to the wavelength multiplexed optical signal receiver 20a is demultiplexed into optical signals of each wavelength by the demultiplexer 22a, and each receiving circuit 21a (R1 to R3). ) And is output as a received signal 52 comprising three signals via the switch 42.

  Here, when a failure occurs in one of the transmission circuits 11a of the wavelength multiplexing optical signal transmission apparatus 10a, for example, T1, the transmission circuit T1 is switched to the transmission circuit T4 by the switch 41, and is converted into an optical signal of wavelength λ4. Is transmitted. On the other hand, the optical signal of wavelength λ4 transmitted to the wavelength multiplexing optical signal receiver 20a is received by the receiving circuit R4, and the switching circuit 42 switches the receiving circuit R1 to the receiving circuit R4 and outputs it. The same applies when a failure occurs in the receiving circuit R1 of the wavelength division multiplexing optical signal receiving apparatus 20a, or when a failure occurs in the optical signal having the wavelength λ1 in the optical transmission line 30a.

  When a failure occurs in the optical transmission line 30a, the switchers 41 and 42 switch the wavelength multiplexed optical signal transmitter from the active system of the wavelength multiplexed optical signal transmitter 10a-optical transmission path 30a-wavelength multiplexed optical signal receiver 20a. 10b—the optical transmission line 30b—the entire system is switched to the backup system of the wavelength division multiplexing optical signal receiver 20b.

Even in the case of the failure of a part of the transmission circuit 11a of the wavelength division multiplexing optical signal transmission apparatus 10a or the failure of the reception circuit 21a of a part of the wavelength division multiplexing optical signal reception apparatus 20a, the entire system from the active system to the standby system can be obtained. Can be dealt with by simple switching.
JP 2002-141867 A

  However, in the optical wavelength division multiplexing communication system of FIG. 1, a wavelength division multiplexing optical signal transmission apparatus having a plurality of transmission circuits and multiplexers, a plurality of reception circuits and a wavelength division demultiplexing element are provided to duplex the optical transmission line. It is necessary to provide multiple multiplexed optical signal receivers. For this reason, the cost is increased, and there are two methods for dealing with the case where a failure occurs only in the portion corresponding to the optical signal of some wavelengths as described above: wavelength switching and switching for each transmission device (reception device). There was a higher redundancy than necessary.

  The present invention was created in view of the above circumstances, and the object of the present invention is to provide a minimum and low-cost configuration that includes a failure in a portion corresponding to an optical signal of each wavelength and a failure in an optical transmission line. It is an object of the present invention to provide a wavelength division multiplexing optical signal transmission apparatus, a wavelength division multiplexing optical signal reception apparatus, and an optical wavelength division multiplexing communication system that can handle both.

  The wavelength division multiplexing optical signal transmission apparatus according to the present invention includes N (N is an integer of 2 or more) optical signal transmission circuits that output optical signals of M types (M is an integer of 2 or more) according to the transmission signal. The M types of wavelengths output from each circuit include N optical signal transmission circuits that are set to form M sets of wavelength groups having different wavelengths, and the N optical signal transmission circuits. It has N input ports to be connected and M output ports to which M optical transmission lines are connected, and an optical signal input from each input port is assigned to each optical signal having a wavelength belonging to each wavelength group. And a multiplexer that outputs the signals to separate output ports. (Claim 1)

  At this time, each optical signal transmission circuit may switch and output an optical signal of a wavelength belonging to each wavelength group among optical signals of M types of wavelengths corresponding to the transmission signal.

  Such an optical signal transmission circuit is composed of a wavelength tunable light source that is driven by a transmission signal and can switch and output optical signals of M types of wavelengths (claim 3), or outputs optical signals of M types of wavelengths, respectively. M possible light emitting elements and an optical switch for switching and outputting optical signals from the M light emitting elements, and the M light emitting elements are switched and driven by a transmission signal (claim 4), or M Equipped with M light-emitting elements that can output optical signals of various wavelengths and optical couplers or optical filters that combine the optical signals from the M light-emitting elements, and the M light-emitting elements are switched by a transmission signal M light-emitting elements that can be driven or can output optical signals of M types of wavelengths, respectively, and an optical switch that switches and outputs optical signals from the M light-emitting elements. Each light-emitting element is driven simultaneously by a transmission signal Is may be a (claim 6) ones.

  Each optical signal transmission circuit may simultaneously output optical signals of M types of wavelengths corresponding to the transmission signal.

  Such an optical signal transmission circuit includes M light emitting elements each capable of outputting optical signals of M types of wavelengths, and an optical coupler or an optical filter for multiplexing the optical signals from the M light emitting elements, The M light emitting elements can be driven simultaneously by a transmission signal (claim 8).

  The multiplexer is composed of an array waveguide diffraction grating having N inputs and M outputs (Claim 9), or a circular array waveguide diffraction grating having N inputs and M outputs (Claim 10). Can do.

  The wavelength division multiplexing optical signal receiving apparatus of the present invention receives N optical signals of M types (M is an integer of 2 or more) and outputs N received signals (N is an integer of 2 or more). N optical signal receiving circuits that are set so as to constitute M sets of wavelength groups each having a different wavelength are connected to the M optical transmission lines. M input ports and N output ports to which the N optical signal receiving circuits are connected, and an optical signal having a wavelength belonging to each wavelength group input from each input port, for each wavelength. And a demultiplexer that outputs the signals to different output ports (claim 11).

  At this time, each optical signal receiving circuit is composed of a light receiving element that receives optical signals of M types of wavelengths and can output received signals (claim 12), or receives optical signals of M types of wavelengths. , M light receiving elements that can output received signals, an optical switch that switches and outputs optical signals from the duplexer to M light receiving elements, and a switch circuit that switches and outputs received signals from the M light receiving elements (Claim 13) or M light receiving elements that can receive optical signals of M types of wavelengths and output received signals, and the optical signals from the demultiplexer to M light receiving elements. An optical switch for switching output and a coupling circuit for synthesizing and outputting received signals from M light receiving elements (claim 14), or receiving optical signals of M types of wavelengths, respectively, M light receiving elements that can be output and light from the duplexer An optical coupler or an optical filter that outputs the signal to both of the M light receiving elements, and a switch circuit that switches and outputs the received signals from the M light receiving elements (claim 15), or M types of wavelengths. M light receiving elements that receive optical signals and can output received signals, optical couplers or optical filters that output optical signals from the duplexers to both M light receiving elements, and M light receiving elements And a coupling circuit for synthesizing and outputting the received signals.

  The duplexer is made of an array waveguide diffraction grating having M inputs and N outputs (Claim 17), or a circular array waveguide diffraction grating having M inputs and N outputs (Claim 18). Can do.

  An optical wavelength division multiplexing communication system according to the present invention includes a wavelength division multiplexing optical signal transmission apparatus according to any one of claims 1 to 10, and a wavelength division multiplexing optical signal reception apparatus according to any one of claims 11 to 18. It comprises M optical transmission lines capable of transmitting wavelength-division multiplexed optical signals connecting these devices (claim 19).

  Furthermore, the optical wavelength division multiplexing communication system of the present invention includes N communication nodes, M wavelength routers having N input ports and N output ports, and the communication nodes and wavelength routers are N × M. 11. An optical wavelength division multiplexing communication system connected via two optical transmission lines, wherein each of the communication nodes is a wavelength division multiplexing optical signal transmission apparatus according to claim 1 and claim 11. A wavelength-multiplexed optical signal receiver according to any one of claims 18 to 20. (Claim 20).

  According to the wavelength division multiplexing optical signal transmission apparatus, wavelength division multiplexing optical signal reception apparatus and optical wavelength division multiplexing communication system of the present invention, when a failure occurs only in a part corresponding to an optical signal of a part of wavelengths in the wavelength division multiplexing optical signal. Can switch to the spare wavelength, and when a failure occurs in the optical transmission line or wavelength router, a configuration for switching to the spare optical transmission line or wavelength router can be realized at low cost.

  At this time, if a transmitter and a receiver that simultaneously transmit and receive optical signals of M types of wavelengths are used, even if a failure occurs only in a portion corresponding to an optical signal of some wavelengths, Even if a failure occurs in the optical transmission path or wavelength router, communication can be continued without requiring switching control.

[First Embodiment]
FIG. 2 shows a first embodiment of an optical wavelength division multiplexing communication system including a wavelength division multiplexing optical signal transmission apparatus and wavelength division multiplexing optical signal reception apparatus according to the present invention. In the figure, reference numerals 30a and 30b denote optical transmission lines; Is a wavelength-multiplexed optical signal transmitter, and 200 is a wavelength-multiplexed optical signal receiver.

  The wavelength division multiplexing optical signal transmission apparatus 100 includes four optical signal transmission circuits 110 (indicated as T1 to T4 when each circuit is shown separately) and the four optical signal transmission circuits 110, respectively. It is composed of a 4-input 2-output (4 × 2) type multiplexer 120 having two input ports and two output ports to which two optical transmission lines 30a and 30b are respectively connected.

  Each of the optical signal transmission circuits 110 has two wavelengths corresponding to transmission signals input to the respective circuits. Here, T1 is λ1, λ2, T2 is λ2, λ3, T3 is λ3, λ4, and T4 is λ4. , Λ5 optical signals are output. The two types of wavelengths described above are set so as to form two sets of wavelength groups composed of different wavelengths. Here, a set of wavelength groups consisting of λ1, λ2, λ3, and λ4 and λ2, λ3, λ4, and λ5 are included. It is set so as to constitute a set of wavelength groups.

  In addition, as will be described later, each optical signal transmission circuit 110 is configured to switch and output only one of the two types of optical signals described above, that is, an optical signal having a wavelength belonging to each wavelength group. However, when switching output is performed, each circuit is switched individually or all circuits simultaneously according to an instruction from a control circuit (not shown).

  The multiplexer 120 multiplexes optical signals input from the input ports for each optical signal having a wavelength belonging to each wavelength group, and outputs the multiplexed optical signals to separate output ports. More specifically, the multiplexer 120 selectively outputs an optical signal input from each input port to an output port corresponding to the input port and the wavelength, and here is the first to which the transmission circuit T1 is connected. The optical signal having the wavelength λ1 input from the input port is output to the first output port 121, the optical signal having the wavelength λ2 is output to the second output port 122, and the second input to which the transmission circuit T2 is connected. The optical signal having the wavelength λ2 input from the port is output to the first output port 121, and the optical signal having the wavelength λ3 is output to the second output port 122. From the third input port to which the transmission circuit T3 is connected. The input optical signal of wavelength λ3 is output to the first output port 121, the optical signal of wavelength λ4 is output to the second output port 122, and input from the fourth input port to which the transmission circuit T4 is connected. Wavelength 4 is output to the first output port 121, and the optical signal having the wavelength λ5 is output to the second output port 122. From the first output port 121, a wavelength group including λ1, λ2, λ3, and λ4. The second output port 122 outputs an optical signal having a wavelength group consisting of λ2, λ3, λ4, and λ5. The relationship between the wavelength and the input / output port in the multiplexer 120 is shown in FIG.

  When the function of the multiplexer 120 is expressed in a general expression, an output port is selected based on the input port and wavelength of the input optical signal, and the combined output is performed. More specifically, for each of the N input ports, The input / output relationship is set so that the optical signal of the mth (1 ≦ m ≦ M) wavelength among the M types of optical signals is output to the mth output port among the M output ports. It has a function to output combined signals.

  The wavelength division multiplexing optical signal receiving apparatus 200 includes two optical signal receiving circuits 210 (R1 to R4 when each circuit is shown separately) and two optical transmission lines 30a and 30b, respectively. It comprises a 2-input 4-output (2 × 4) type duplexer 220 having four input ports and four output ports to which the four optical signal receiving circuits 210 are respectively connected.

  Each of the optical signal receiving circuits 210 constitutes two types of wavelengths, here, two sets of wavelength groups λ1, λ2, λ3, λ4 and λ2, λ3, λ4, λ5 in the wavelength multiplexed optical signal transmitting apparatus 100 described above. Receive optical signals of two wavelengths set as follows: R1 is λ1, λ2, R2 is λ2, λ3, R3 is λ3, λ4, R4 is λ4, λ5. The received signal is output.

  As will be described later, each optical signal receiving circuit 210 is configured to switch and receive only one of the above-described two types of wavelengths, that is, an optical signal having a wavelength belonging to each wavelength group. There are cases where both are configured to receive simultaneously, but when switching is received, each circuit is switched individually or all circuits simultaneously according to an instruction from a control circuit (not shown). However, as the optical signal receiving circuit 210, even if the optical signal transmitting circuit 110 switches and outputs optical signals of two types of wavelengths, it is necessary to use one that switches and receives optical signals of two types of wavelengths. However, it is also possible to use one that receives both at the same time.

  The demultiplexer 220 demultiplexes the optical signals having the wavelengths belonging to the wavelength groups input from the input ports for each wavelength, and outputs the demultiplexed signals to different output ports. More specifically, the duplexer 220 selectively outputs an optical signal input from each input port to an output port corresponding to the input port and wavelength. Here, the optical transmission line 30a is connected to the 1 The optical signal of the wavelength group consisting of λ1, λ2, λ3, and λ4 input from the first input port 221 is output to the first output port for the optical signal of wavelength λ1, and to the second output for the optical signal of wavelength λ2. The optical signal of wavelength λ3 is output to the third output port, the optical signal of wavelength λ4 is output to the fourth output port, and the second optical signal line 30b is connected. An optical signal having a wavelength group consisting of λ2, λ3, λ4, and λ5 input from the input port 222 is transmitted to the first output port for the optical signal having the wavelength λ2, and to the second output port for the optical signal having the wavelength λ3. The optical signal with wavelength λ4 is output at the third And outputs to the port, also, the optical signal of the wavelength λ5 is made as to output to the fourth output port. The relationship between the wavelength and the input / output port in the duplexer 220 is shown in FIG.

  When the function of the duplexer 220 is expressed in a general expression, the output port is selected based on the input port and wavelength of the input optical signal, and output is demultiplexed, more specifically, for each of the M input ports. The input / output relationship is set so that the optical signal having the nth (1 ≦ n ≦ N) wavelength among the optical signals having the wavelengths belonging to each wavelength group is output to the nth output port among the N output ports. And has a function of outputting a demultiplexed wave.

  In the wavelength division multiplexing optical signal transmission apparatus 100 and the wavelength division multiplexing optical signal reception apparatus 200, the output port 121 of the multiplexer 120 and the input port 221 of the demultiplexer 220 are connected via the optical transmission line 30a. The output port 122 of 120 and the input port 222 of the duplexer 220 are connected via the optical transmission line 30b to constitute a duplexed optical wavelength division multiplexing communication system.

  In the above-described configuration, a transmission signal, for example, a transmission signal 61 composed of four signals, is input to the wavelength-multiplexed optical signal transmission apparatus 100, and each transmission circuit 110, for example, an optical signal of a wavelength group composed of wavelengths λ1 to λ4, that is, T1 Is converted to an optical signal of λ1, T2 of λ2, T3 of λ3, and T4 of λ4, multiplexed by the multiplexer 120, and wavelength-multiplexed. From the output port 121 through the optical transmission line 30a, the wavelength-multiplexed optical signal It is transmitted to the receiving device 200. A wavelength-multiplexed optical signal consisting of optical signals of the wavelength group consisting of wavelengths λ1 to λ4 transmitted to the wavelength-multiplexed optical signal receiving apparatus 200 is input to the input port 221 of the demultiplexer 220 and demultiplexed into optical signals of each wavelength. Then, each receiving circuit 210 receives an optical signal of λ1 at R1, λ2 at R2, λ3 at R3, and λ4 at R4, and is converted into a received signal 62 composed of four signals and output.

  The transmission signal 61 and the reception signal 62 include both electric signals and optical signals.

  Here, when a failure occurs in the optical transmission line 30a, each optical signal transmission circuit 110 is controlled to output an optical signal of a wavelength group consisting of wavelengths λ2 to λ5 in accordance with an instruction from a control circuit (not shown), that is, T1. Is controlled to output optical signals of λ2, T2 of λ3, T3 of λ4, and T4 of λ5. These optical signals are combined by the multiplexer 120 and wavelength-multiplexed as described above. In this case, the optical signals are transmitted from the output port 122 to the wavelength-multiplexed optical signal receiver 200 via the optical transmission line 30b. The wavelength multiplexed optical signal composed of the optical signals of the wavelength group consisting of the wavelengths λ2 to λ5 transmitted to the wavelength multiplexed optical signal receiving apparatus 200 is input to the input port 222 of the demultiplexer 220 and is demultiplexed into the optical signals of the respective wavelengths. In this case, an optical signal of λ2 at R1, λ3 at R2, λ4 at R3, and λ5 at R4 is received and output as a received signal 62 consisting of four signals. .

  At this time, when each optical signal receiving circuit 210 of the wavelength division multiplexing optical signal receiving apparatus 200 switches and receives an optical signal of a wavelength group consisting of wavelengths λ1 to λ4 or a wavelength group consisting of wavelengths λ2 to λ5, In accordance with an instruction from a control circuit (not shown) according to the control on the transmission side, the optical signal of the wavelength group consisting of wavelengths λ1 to λ4 is controlled from the state of receiving the optical signal of wavelength group consisting of wavelengths λ2 to λ5. Shall be.

  When a failure occurs in an optical signal having a certain wavelength, for example, the wavelength λ1, in the optical transmission line 30a, only the optical signal transmission circuit 110 that outputs an optical signal corresponding to the wavelength, that is, T1 (optical signal reception) If the circuit 210 switches and receives the optical signal of each wavelength group (including the corresponding optical signal receiving circuit R2), it can be dealt with by switching the wavelength of the optical signal to be output, that is, switching to λ2. Needless to say.

  Further, as each optical signal transmission circuit 110 of the wavelength division multiplexing optical signal transmission apparatus 100 and each optical signal reception circuit 210 of the wavelength division multiplexing optical signal reception apparatus 200, a wavelength group consisting of wavelengths λ1 to λ4 and a wavelength group consisting of wavelengths λ2 to λ5. When a wavelength-multiplexed optical signal is transmitted using both of the optical transmission lines 30a and 30b, and a failure occurs in either of the optical transmission lines 30a or 30b. Even including obstacles to some wavelengths), communication can be continued without requiring any control.

  An optical amplification repeater may be inserted into the optical transmission lines 30a and 30b as necessary. Further, here, a configuration is shown in which M = 2 and the optical transmission path is duplexed. However, transmission may be performed in parallel on an optical transmission path of M = 3 or more, in which case transmission corresponding to M types of wavelengths is possible. A circuit and a receiving circuit, an N-input M-output multiplexer, and an M-input N-output duplexer may be used.

  FIG. 5 shows an example of a detailed configuration of the optical signal transmission circuit 110 and the optical signal reception circuit 210 in the first embodiment. Here, one of the four systems shown in FIG. 2 (T1, R1). ) Only, and the other three systems are omitted.

  In the figure, reference numeral 111 denotes a wavelength tunable light source (TLD), which constitutes an optical signal transmission circuit 110. The wavelength tunable light source 111 is driven by a transmission signal (electric signal), and switches and outputs two types of wavelengths, λ1 and λ2 optical signals according to the transmission signal, in accordance with an instruction from a control circuit (not shown).

  Reference numeral 211 denotes a light receiving element (PD), which constitutes an optical signal receiving circuit 210. The light receiving element 211 receives optical signals of two types of wavelengths, here λ1 or λ2, or both, and outputs a received signal (electric signal) corresponding to the optical signal.

  When the received signal 61 (one of them) is input to such an optical signal transmission circuit 110, it is converted into an optical signal of λ1 by the wavelength variable light source 111 and input to the multiplexer 120, and other wavelengths ( Wavelength-multiplexed with the optical signals λ2 to λ4 (omitted in the figure) and output from the output port 121 to the optical transmission line 30a. The wavelength multiplexed optical signal transmitted through the optical transmission line 30 a is input to the input port 221 of the demultiplexer 220 and is demultiplexed, and the optical signal of wavelength λ1 is received by the light receiving element 211 of the optical signal receiving circuit 210. , Converted into a received signal 62 and output.

  Here, when a failure occurs in the optical transmission line 30a, the output wavelength of the wavelength variable light source 111 of the optical signal transmission circuit 110 (T1) is changed from λ1 to λ2 in accordance with an instruction from a control circuit (not shown). In other omitted wavelength variable light sources, the wavelength is changed from λ2 → λ3, λ3 → 4, λ4 → 5. As described above, the optical signals having the wavelengths λ2 to λ5 are combined by the multiplexer 120 to become a wavelength multiplexed optical signal. However, since the output port is changed to 122, the optical signal is output to the optical transmission line 30b. On the receiving side, the signal is input to the input port 222 of the duplexer 220 and demultiplexed. The optical signal having the wavelength λ2 is received by the light receiving element 211 of the optical signal receiving circuit 210 (R1), converted into the received signal 62, and output. Is done.

  As the wavelength tunable light source 111, any type of element such as an element that changes the element temperature of a laser diode, an element that changes the resonator length, an element that changes an injection current, and a multiwavelength light source element can be applied. As the light receiving element 211, a photodiode can be used.

  Further, the multiplexer 120 and the duplexer 220 can be configured by an arrayed waveguide diffraction grating (AWG) or a dielectric multilayer filter.

  FIG. 6 shows another example of the detailed configuration of the optical signal transmission circuit 110 and the optical signal reception circuit 210 in the first embodiment. Like FIG. 5, one of the four systems shown in FIG. Only the minute was shown, and the other three lines were omitted.

  In the figure, 112 and 113 are light emitting elements (LD), 114 is a switch circuit (electric switch), and 115 is an optical switch, and these constitute an optical signal transmission circuit 110. The light emitting elements 112 and 113 are driven by transmission signals (electrical signals), and output optical signals having different wavelengths according to the transmission signals, here, λ1 and λ2. The switch circuit 114 supplies a transmission signal (electric signal) to either the light emitting element 112 or 113 in accordance with an instruction from a control circuit (not shown). The optical switch 115 inputs one of the optical signals output from the light emitting elements 112 and 113 to the multiplexer 120 in accordance with an instruction from a control circuit (not shown).

  In addition, 212 and 213 are light receiving elements (PD), 214 is an optical switch, 215 is a switch circuit (electric switch), and the optical signal receiving circuit 210 is constituted by these. The light receiving elements 212 and 213 receive optical signals having different wavelengths, here λ1 and λ2, and output reception signals (electrical signals) corresponding to the optical signals. The optical switch 214 supplies an optical signal output from the duplexer 220 to either the light receiving element 212 or 213 in accordance with an instruction from a control circuit (not shown). The switch circuit 215 outputs one of the reception signals output from the light receiving elements 212 and 213 in accordance with an instruction from a control circuit (not shown).

  In such a configuration, the optical signal transmission circuit is controlled so that the switch circuit 114 and the optical switch 115 select the light emitting element 112, and the optical switch 214 and the switch circuit 215 select the light receiving element 212. When the received signal 61 (one of them) is input to 110, it is supplied to the light emitting element 112 via the switch circuit 114, converted into an optical signal of λ1 by the light emitting element 112, and then passed through the optical switch 115. The signal is input to the multiplexer 120, wavelength-multiplexed with optical signals of other wavelengths (λ2 to λ4, not shown), and output from the output port 121 to the optical transmission line 30a. The wavelength multiplexed optical signal transmitted through the optical transmission line 30 a is input to the input port 221 of the demultiplexer 220 and demultiplexed, and the optical signal of wavelength λ1 is transmitted through the optical switch 214 of the optical signal receiving circuit 210. Light is received by the light receiving element 212, converted into a reception signal 62, and output via the switch circuit 215.

  Here, when a failure occurs in the optical signal transmission circuit 110 (T1), particularly the light emitting element 112, the switch circuit 114 and the optical switch 115 select the light emitting element 113 in accordance with an instruction from a control circuit (not shown), and the optical switch 214 and the switch circuit 215 are controlled to select the light receiving element 213. As a result, the wavelength of the optical signal input from the optical signal transmission circuit 110 (T1) to the multiplexer 120 is changed from λ1 to λ2, so the output port changes to 122 and is output to the optical transmission line 30b. On the receiving side, the light is input to the input port 222 of the demultiplexer 220 and demultiplexed, and the optical signal having the wavelength λ2 is received by the light receiving element 213 of the optical signal receiving circuit 210 (R1), converted into the received signal 62, and output. Is done.

  The same applies when a failure occurs in the optical signal receiving circuit 210 (R1), in particular, the light receiving element 212, or a failure occurs in the optical signal having the wavelength λ1 in the optical transmission line 30a.

  When a failure occurs in the optical transmission line 30a, the switch circuit 114 and the optical switch 115 select the light emitting element 113 in all four systems of the optical signal transmission circuit 110 and the optical signal reception circuit 210, and the optical switch It goes without saying that 214 and the switch circuit 215 are controlled so as to select the light receiving element 213 and the wavelength used is changed from λ1 → 2, λ2 → λ3, λ3 → 4, λ4 → 5.

  In the optical signal transmission circuit 110, an optical coupler or an optical filter for multiplexing optical signals from the light emitting elements 112 and 113 may be used instead of the optical switch 115. Further, the transmission signal is supplied to both the light emitting elements 112 and 113 by omitting the switch circuit 114 (or in place of an appropriate branch circuit), and two types of light corresponding to the transmission signal from both the light emitting elements 112 and 113. A signal may be output. Furthermore, an optical coupler or an optical filter is used in place of the optical switch 115, a transmission signal is supplied to both the light emitting elements 112 and 113, and an optical signal is simultaneously output from both the light emitting elements 112 and 113, thereby transmitting. It is also possible to configure the optical signal transmission circuit 110 that simultaneously outputs optical signals of two types of wavelengths corresponding to the signals.

  In the optical signal receiving circuit 210, a coupling circuit that synthesizes and outputs received signals from the light receiving elements 212 and 213 may be used instead of the switch circuit 215. Further, instead of the optical switch 214, an optical coupler or an optical filter is used to supply an optical signal from the duplexer 220 to both the light receiving elements 212 and 213, and reception according to the optical signal from both the light receiving elements 212 and 213. A signal may be output. Furthermore, by using a coupling circuit instead of the switch circuit 215 and using an optical coupler or optical filter instead of the optical switch 214, it is possible to simultaneously output reception signals corresponding to optical signals of two types of wavelengths. You can also.

  Furthermore, the optical signal transmission circuit using the wavelength tunable light source shown in FIG. 5 or the optical signal reception circuit using a single light receiving element is combined with the optical signal transmission circuit or optical signal reception circuit shown in FIG. Also good.

  As described above, according to the optical wavelength division multiplexing transmission system of the present embodiment, the optical transmission path can be backed up by one set of the wavelength division multiplexing optical signal transmission device 100 and the wavelength division multiplexing optical signal reception device 200, and further, the wavelength unit. Can also be backed up.

[Second Embodiment]
FIG. 7 shows a second embodiment of an optical wavelength division multiplexing communication system including the wavelength division multiplexing optical signal transmission apparatus and wavelength division multiplexing optical signal reception apparatus of the present invention. Here, the multiplexer of the wavelength division multiplexing optical signal transmission apparatus is shown. In addition, an example is shown in which a demultiplexer of a wavelength division multiplexing optical signal receiving apparatus has a wavelength revolving property.

  That is, in the figure, reference numeral 310 denotes a wavelength division multiplexing optical signal transmission apparatus, which includes four optical signal transmission circuits 311 (represented by T1 to T4 when each circuit is shown separately) and the four optical signal transmission circuits. A 4 input 2 output (4 × 2) type multiplexer 312 having 4 input ports to which 311 is connected and 2 output ports to which 2 optical transmission lines 30a and 30b are respectively connected. It is configured.

  Each of the optical signal transmission circuits 311 has two wavelengths corresponding to transmission signals input to the respective circuits. Here, T1 is λ1, λ2, T2 is λ2, λ3, T3 is λ3, λ4, and T4 is λ4. , Λ1 optical signals are output. The two types of wavelengths described above are set so as to form two sets of wavelength groups composed of mutually different wavelengths. Here, a set of wavelength groups consisting of λ1, λ2, λ3, and λ4, and λ2, λ3, λ4, and λ1. It is set so as to constitute a set of wavelength groups.

  The multiplexer 312 multiplexes the optical signals input from the input ports for each optical signal having a wavelength belonging to each wavelength group, and outputs the combined optical signal to each output port. More specifically, the multiplexer 312 selectively outputs an optical signal input from each input port to an output port corresponding to the input port and the wavelength, and here is the first to which the transmission circuit T1 is connected. The optical signal having the wavelength λ1 input from the input port is output to the first output port 313, the optical signal having the wavelength λ2 is output to the second output port 314, and the second input to which the transmission circuit T2 is connected. The optical signal of wavelength λ2 input from the port is output to the first output port 313, and the optical signal of wavelength λ3 is output to the second output port 314, from the third input port to which the transmission circuit T3 is connected. The input optical signal of wavelength λ3 is output to the first output port 313, the optical signal of wavelength λ4 is output to the second output port 314, and input from the fourth input port to which the transmission circuit T4 is connected. Wavelength 4 optical signal is output to the first output port 313, and the optical signal of wavelength λ1 is output to the second output port 314. From the first output port 313, a wavelength group consisting of λ1, λ2, λ3, and λ4 The second output port 314 outputs an optical signal having a wavelength group consisting of λ2, λ3, λ4, and λ1. The relationship between the wavelength and the input / output port in the multiplexer 312 is shown in FIG.

  Reference numeral 320 denotes a wavelength division multiplexing optical signal receiving device, which includes four optical signal receiving circuits 321 (indicated as R1 to R4 when each circuit is shown separately) and two optical transmission lines 30a and 30b, respectively. 2 input 4 output (2 × 4) type duplexer 322 having 2 input ports to be connected and 4 output ports to which the 4 optical signal receiving circuits 321 are respectively connected. Yes.

  Each of the optical signal receiving circuits 321 constitutes two types of wavelengths, here, two sets of wavelength groups λ1, λ2, λ3, λ4 and λ2, λ3, λ4, λ1 in the wavelength-multiplexed optical signal transmitter 310 described above. Receive optical signals of two wavelengths set as follows: R1 is λ1, λ2, R2 is λ2, λ3, R3 is λ3, λ4, R4 is λ4, λ1. The received signal is output.

  The demultiplexer 322 demultiplexes the optical signal input from each input port for each optical signal having a wavelength belonging to each wavelength group and outputs the demultiplexed optical signal to each output port. More specifically, the duplexer 322 selectively outputs an optical signal input from each input port to an output port corresponding to the input port and the wavelength, and here, the optical transmission line 30a is connected to the 1 The optical signal of the wavelength group consisting of λ1, λ2, λ3, and λ4 input from the first input port 323, the optical signal of wavelength λ1 to the first output port, and the optical signal of wavelength λ2 to the second output The optical signal of wavelength λ3 is output to the third output port, the optical signal of wavelength λ4 is output to the fourth output port, and the second optical signal line 30b is connected. An optical signal having a wavelength group consisting of λ2, λ3, λ4, and λ1 input from the input port 324, an optical signal having the wavelength λ2 to the first output port, and an optical signal having the wavelength λ3 to the second output port. The optical signal with wavelength λ4 is output at the third And outputs to the port, also, the optical signal of wavelength λ1 is made as to output to the fourth output port. FIG. 9 shows the relationship between the wavelength and the input / output port in the duplexer 322.

  The wavelength multiplexed optical signal transmitter 310 and the wavelength multiplexed optical signal receiver 320 are configured such that the output port 313 of the multiplexer 312 and the input port 323 of the duplexer 322 are connected via the optical transmission line 30a. The output port 314 of 312 and the input port 324 of the demultiplexer 322 are connected via the optical transmission line 30b to constitute a duplexed optical wavelength division multiplexing communication system.

  In the above-described configuration, a transmission signal, for example, a transmission signal 61 composed of four signals, is input to the wavelength-multiplexed optical signal transmission device 310, and each transmission circuit 311 has an optical signal of a wavelength group composed of, for example, wavelengths λ1 to λ4, that is, T1. Is converted into an optical signal of λ1, T2 of λ2, T3 of λ3, and T4 of λ4, multiplexed by a multiplexer 312 and wavelength-multiplexed, and output from its output port 313 via an optical transmission line 30a. It is transmitted to the receiving device 320. The wavelength multiplexed optical signal composed of the optical signals of the wavelength group consisting of the wavelengths λ1 to λ4 transmitted to the wavelength multiplexed optical signal receiving device 320 is input to the input port 323 of the demultiplexer 322 and demultiplexed into optical signals of each wavelength. Then, each receiving circuit 321 receives an optical signal of λ1, R2, λ2, R3, λ3, and R4, λ4, and is converted into a received signal 62 composed of four signals.

  Here, when a failure occurs in the optical transmission line 30a, each optical signal transmission circuit 311 is controlled to output an optical signal having a wavelength group consisting of wavelengths λ2 to λ1, in accordance with an instruction from a control circuit (not shown), that is, T1. Is controlled to output optical signals of λ2, T2 of λ3, T3 of λ4, and T4 of λ1. These optical signals are combined and wavelength-multiplexed by the multiplexer 312 as described above. In this case, the optical signals are transmitted from the output port 314 to the wavelength-multiplexed optical signal receiver 320 via the optical transmission line 30b. The wavelength multiplexed optical signal composed of the optical signals of the wavelength group consisting of wavelengths λ2 to λ1 transmitted to the wavelength multiplexed optical signal receiving device 320 is input to the input port 324 of the demultiplexer 322 and is demultiplexed into the optical signals of the respective wavelengths. In this case, an optical signal of λ2 at R1, λ3 at R2, λ4 at R3, and λ1 at R4 is received and output as a received signal 62 composed of four signals. .

  As in the case of the first embodiment, each optical signal transmission circuit 311 may output both optical signals of two types of wavelengths at the same time, and each optical signal reception circuit 321 has two types. Only one of the optical signals having the wavelength of 2 may be switched and received, or both may be received simultaneously. Further, it goes without saying that the details of each optical signal transmission circuit 311 and each optical signal reception circuit 321 can also be realized with the same configuration as in FIGS. 5 and 6 described in the first embodiment. .

[Third Embodiment]
FIG. 10 shows a third embodiment of an optical wavelength division multiplexing communication system including the wavelength division multiplexing optical signal transmission apparatus and wavelength division multiplexing optical signal reception apparatus of the present invention. Here, the multiplexer of the wavelength division multiplexing optical signal transmission apparatus is shown. In addition, an example in which a demultiplexer of the wavelength division multiplexing optical signal receiving apparatus has no wavelength recursion is shown.

  That is, in the figure, reference numeral 410 denotes a wavelength division multiplexing optical signal transmission apparatus, which includes four optical signal transmission circuits 411 (each circuit is represented by T1 to T4) and the four optical signal transmission circuits. A 4-input 2-output (4 × 2) type multiplexer 412 having four input ports to which 411 is connected and two output ports to which two optical transmission lines 30a and 30b are respectively connected. It is configured.

  Each of the optical signal transmission circuits 411 has two wavelengths corresponding to transmission signals input to the respective circuits. Here, T1 is λ1, λ5, T2 is λ2, λ6, T3 is λ3, λ7, and T4 is λ4. , Λ8 optical signals are output. The above-mentioned two types of wavelengths are set so as to form two sets of wavelength groups composed of mutually different wavelengths. Here, a set of wavelength groups composed of λ1, λ2, λ3, and λ4, and λ5, λ6, λ7, and λ8. It is set so as to constitute a set of wavelength groups.

  The multiplexer 412 multiplexes the optical signals input from the input ports for each optical signal having a wavelength belonging to each wavelength group, and outputs the combined optical signal to each output port. More specifically, the multiplexer 412 selectively outputs an optical signal input from each input port to an output port corresponding to the input port and the wavelength, and here is the first to which the transmission circuit T1 is connected. The optical signal having the wavelength λ1 input from the input port is output to the first output port 413, the optical signal having the wavelength λ5 is output to the second output port 414, and the second input to which the transmission circuit T2 is connected. The optical signal of wavelength λ2 input from the port is output to the first output port 413, and the optical signal of wavelength λ6 is output to the second output port 414. From the third input port to which the transmission circuit T3 is connected The input optical signal of wavelength λ3 is output to the first output port 413 and the optical signal of wavelength λ7 is output to the second output port 414, and input from the fourth input port to which the transmission circuit T4 is connected. Wavelength 4 is output to the first output port 413, and the optical signal having the wavelength λ8 is output to the second output port 414. From the first output port 413, a wavelength group consisting of λ1, λ2, λ3, and λ4 The second output port 414 outputs an optical signal having a wavelength group consisting of λ5, λ6, λ7, and λ8. FIG. 11 shows the relationship between the wavelength and the input / output port in the multiplexer 412.

  Reference numeral 420 denotes a wavelength-multiplexed optical signal receiving device, which includes four optical signal receiving circuits 421 (represented by R1 to R4 when each circuit is shown separately) and two optical transmission lines 30a and 30b. It is composed of a 2-input 4-output (2 × 4) type duplexer 422 having two input ports to be connected and four output ports to which the four optical signal receiving circuits 421 are respectively connected. Yes.

  Each of the optical signal receiving circuits 421 constitutes two types of wavelengths, here, two sets of wavelength groups λ1, λ2, λ3, λ4 and λ5, λ6, λ7, λ8 in the wavelength multiplexing optical signal transmission apparatus 410 described above. Receive optical signals of two wavelengths set as follows: R1 receives λ1, λ5, R2 receives λ2, λ6, R3 receives λ3, λ7, R4 receives λ4, λ8 optical signals, and responds to the optical signals The received signal is output.

  The demultiplexer 422 demultiplexes the optical signal input from each input port for each optical signal having a wavelength belonging to each wavelength group and outputs the demultiplexed optical signal to each output port. More specifically, the duplexer 422 selectively outputs an optical signal input from each input port to an output port corresponding to the input port and the wavelength, and here, the optical transmission line 30a is connected to the 1 An optical signal having a wavelength group consisting of λ1, λ2, λ3, and λ4 input from the first input port 423, an optical signal having the wavelength λ1 to the first output port, and an optical signal having the wavelength λ2 to the second output The optical signal of wavelength λ3 is output to the third output port, the optical signal of wavelength λ4 is output to the fourth output port, and the second optical signal line 30b is connected. An optical signal having a wavelength group consisting of λ5, λ6, λ7, and λ8 input from the input port 424 is transmitted to the first output port for the optical signal having the wavelength λ5, and to the second output port for the optical signal having the wavelength λ6. The optical signal with wavelength λ7 is the third output. And outputs to the port, also, the optical signal of the wavelength λ8 is made as to output to the fourth output port. The relationship between the wavelength and the input / output port in the duplexer 422 is shown in FIG.

  The wavelength multiplexed optical signal transmitter 410 and the wavelength multiplexed optical signal receiver 420 are configured such that the output port 413 of the multiplexer 412 and the input port 423 of the duplexer 422 are connected via the optical transmission line 30a. The output port 414 of 412 and the input port 424 of the duplexer 422 are connected via the optical transmission line 30b to constitute a duplexed optical wavelength division multiplexing communication system.

  In the above-described configuration, a transmission signal, for example, a transmission signal 61 composed of four signals, is input to the wavelength-multiplexed optical signal transmission apparatus 410, and each transmission circuit 411, for example, an optical signal of a wavelength group composed of wavelengths λ1 to λ4, that is, T1. Is converted to an optical signal of λ1, T2 of λ2, T3 of λ3, and T4 of λ4, multiplexed by a multiplexer 412 and wavelength-multiplexed, and output from its output port 413 via an optical transmission line 30a. It is transmitted to the receiving device 420. A wavelength-multiplexed optical signal consisting of optical signals of the wavelength group consisting of wavelengths λ1 to λ4 transmitted to the wavelength-multiplexed optical signal receiving device 420 is input to the input port 423 of the demultiplexer 422 and demultiplexed into optical signals of each wavelength. Then, each receiving circuit 421 receives, that is, an optical signal of λ1 at R1, λ2 at R2, λ3 at R3, and λ4 at R4, converted into a received signal 62 composed of four signals, and output.

  When a failure occurs in the optical transmission line 30a, each optical signal transmission circuit 411 is controlled to output an optical signal having a wavelength group consisting of wavelengths λ5 to λ8 in accordance with an instruction from a control circuit (not shown), that is, T1. Is controlled to output optical signals of λ5, T2 of λ6, T3 of λ7, and T4 of λ8. These optical signals are multiplexed by the multiplexer 412 and wavelength-multiplexed as described above. In this case, the optical signals are transmitted from the output port 414 to the wavelength-multiplexed optical signal receiver 420 via the optical transmission line 30b. The wavelength multiplexed optical signal composed of the optical signals of the wavelength group consisting of wavelengths λ5 to λ8 transmitted to the wavelength multiplexed optical signal receiving device 420 is input to the input port 424 of the demultiplexer 422 and demultiplexed into optical signals of each wavelength. In this case, an optical signal of λ5 at R1, λ6 at R2, λ7 at R3, and λ8 at R4 is received and output as a received signal 62 composed of four signals. .

  As in the case of the first embodiment, each optical signal transmission circuit 411 may output both optical signals of two types of wavelengths at the same time, and each optical signal reception circuit 421 has two types. Only one of the optical signals having the wavelength of 2 may be switched and received, or both may be received simultaneously. Further, it goes without saying that the details of each optical signal transmission circuit 411 and each optical signal reception circuit 421 can also be realized with the same configuration as in FIGS. 5 and 6 described in the first embodiment. .

[Fourth Embodiment]
FIG. 13 shows a fourth embodiment of an optical wavelength division multiplexing communication system according to the present invention, in this case, N communication nodes and M wavelength routers composed of a wavelength division multiplexing optical signal transmission apparatus and a wavelength division multiplexing optical signal reception apparatus. Shows an example of a system in which N is connected via N × M × 2 optical transmission lines.

  That is, in the figure, 501, 502, 503 and 504 are four communication nodes, 601 and 602 are two wavelength routers, 701, 702, 703, 704, 705, 706, 707 and 708 are eight optical transmissions. (N × M × 2 out of “N × M × 2” represents a round-trip portion and is omitted in this figure), and nodes 501, 502, 503, and 504 are optical transmission paths 701, The active system is configured by being connected to the wavelength router 601 via 702, 703, and 704, and the standby system is configured by being connected to the wavelength router 602 via the optical transmission lines 705, 706, 707, and 708. .

  Each of the communication nodes 501 to 504 includes a wavelength multiplexing optical transmitter and a wavelength multiplexing optical receiver that transmit and receive optical signals of N = 4 wavelengths, and is wavelength-routed by the wavelength router 601 or 602, and is a full mesh between the nodes. Connection is realized.

  FIG. 14 shows an example of a detailed configuration of the communication node, here, only one of the four communication nodes shown in FIG. 13, that is, only the communication node 501, will be described below along with the operation of the wavelength router. To do.

  The communication node 501 includes the wavelength multiplexed optical signal transmitter 100 and the wavelength multiplexed optical signal receiver 200 shown in FIG. 2, and the output ports 121 and 122 of the multiplexer 120 of the wavelength multiplexed optical signal transmitter 100 and the wavelength router. 601 and 602 are respectively connected via M (= 2) optical fibers 701 and 705 (for the forward path), and the input ports 221 and 222 of the duplexer 220 of the wavelength multiplexed optical signal receiving apparatus 200 are connected to the wavelength. Similarly, routers 601 and 602 are connected via optical fibers 701 and 705 (for return path), respectively.

  Here, the wavelength routing table of the wavelength router 601 is shown in FIG. 15, and the wavelength routing table of the wavelength router 602 is shown in FIG.

  In the active system, the wavelength multiplexed optical signal transmitted from the wavelength multiplexed optical signal transmission apparatus 100 of the communication node 501 via the optical transmission path 701 (outward path) is routed by the wavelength router 601 according to the wavelength routing table shown in FIG. The That is, the optical signal of λ1 is returned to the communication node 501, the optical signal of λ2 is routed to the communication node 502, the optical signal of λ3 is routed to the communication node 503, and the optical signal of λ4 is routed to the communication node 504. Wavelength multiplexed optical signals sent from other communication nodes via the active optical transmission paths 702, 703, and 704 are also routed in the same manner, and then multiplexed again to form a transmission path 701 (return path) as a wavelength multiplexed optical signal. ) Is received by the wavelength multiplexing optical signal receiver 200 of the communication node 501.

  Here, when a failure occurs in the optical transmission line 701, each optical signal transmission circuit 110 of the wavelength division multiplexing optical signal transmission device 100 receives an optical signal of a wavelength group consisting of wavelengths λ2 to λ5 in accordance with an instruction from a control circuit (not shown). Control is performed so that an optical signal with T1 of λ2, T2 of λ3, T3 of λ4, and T4 of λ5 is output. These optical signals are multiplexed by the multiplexer 120 and wavelength-multiplexed in the same manner as described above. In this case, the optical signal is transmitted from the output port 122 to the wavelength router 602 via the optical transmission line 705, and is transmitted to the wavelength router 602 in FIG. Are routed according to the wavelength routing table shown in FIG. That is, the optical signal of λ2 is returned to the communication node 501, the optical signal of λ3 is routed to the communication node 502, the optical signal of λ4 is routed to the communication node 503, and the optical signal of λ5 is routed to the communication node 504. Wavelength multiplexed optical signals sent from other communication nodes via backup optical transmission paths 706, 707, and 708 are also routed in the same manner, and then multiplexed again to form a transmission path 702 (return path) as a wavelength multiplexed optical signal. ) Is received by the wavelength multiplexing optical signal receiver 200 of the communication node 501.

  FIG. 17 shows another example of the detailed configuration of the communication node, here, only one of the four communication nodes shown in FIG. 13, ie, only the communication node 501 is shown. It explains together.

  The communication node 501 includes the wavelength multiplexed optical signal transmitter 310 and the wavelength multiplexed optical signal receiver 320 shown in FIG. 7, and the output ports 313 and 314 of the multiplexer 312 of the wavelength multiplexed optical signal transmitter 310 and the wavelength router. 601 and 602 are connected to each other via M (= 2) optical fibers 701 and 705 (for the forward path), and the input ports 323 and 324 of the duplexer 322 of the wavelength division multiplexing optical signal receiving apparatus 320 are connected to the wavelength. Similarly, routers 601 and 602 are connected via optical fibers 701 and 705 (for return path), respectively.

  In this case, the wavelength routing table of the active wavelength router 601 is the same as that in FIG. 15, and the wavelength routing table of the standby wavelength router 602 is shown in FIG.

  With this configuration method, a redundant configuration of full mesh connection between nodes by wavelength routing can be realized between the communication node 501 and the communication node 504.

  Although the wavelength routers 601 and 602 have different wavelength routing tables, optical components having the same characteristics may be used and only the input port numbering may be changed.

  An optical amplification repeater may be inserted into the optical transmission lines 701 to 708 as necessary. In addition, here, a configuration is shown in which M = 2 and the optical transmission path is duplexed. However, transmission may be performed in parallel to an optical transmission path of M = 3 or more. In this case, N input M output multiplexing is performed. And a M-input N-output duplexer may be used.

  The wavelength arrangement shown as an example so far is not limited to this, and is determined by which port of the multiplexer / demultiplexer to be used and the input / output port of the wavelength router to be connected. Is possible.

  The number M of multiplexing, the number N of ports of the optical wavelength router, and the number N of transmission / reception devices used in the above description are not limited to these numbers.

  On the other hand, in configuring a network, an amplifier may be required due to optical transmission loss, but this optical amplifier may be installed anywhere between the transmitting and receiving apparatuses.

Configuration diagram showing an example of a conventional optical wavelength division multiplexing communication system The block diagram which shows 1st Embodiment of the optical wavelength division multiplexing communication system of this invention Explanatory drawing which shows the relationship between the wavelength in the multiplexer of the wavelength division multiplexing optical signal transmitter of 1st Embodiment, and an input / output port Explanatory drawing which shows the relationship between the wavelength and input / output port in the duplexer of the wavelength division multiplexing optical signal receiver of the first embodiment The figure which shows an example of the detailed structure of the optical signal transmission circuit and optical signal receiving circuit in 1st Embodiment The figure which shows the other example of the detailed structure of the optical signal transmission circuit in 1st Embodiment, and an optical signal receiving circuit The block diagram which shows 2nd Embodiment of the optical wavelength division multiplexing communication system of this invention Explanatory drawing which shows the relationship between the wavelength in the multiplexer of the wavelength division multiplexing optical signal transmitter of 2nd Embodiment, and an input / output port Explanatory drawing which shows the relationship between the wavelength in an optical demultiplexer of the wavelength division multiplexing optical signal receiver of 2nd Embodiment, and an input / output port The block diagram which shows 3rd Embodiment of the optical wavelength division multiplexing communication system of this invention Explanatory drawing which shows the relationship between the wavelength and input / output port in the multiplexer of the wavelength division multiplexing optical signal transmitter of 3rd Embodiment Explanatory drawing which shows the relationship between the wavelength and input / output port in the splitter of the wavelength division multiplexing optical signal receiver of 3rd Embodiment The block diagram which shows 4th Embodiment of the optical wavelength division multiplexing communication system of this invention The figure which shows an example of a detailed structure of the communication node in 4th Embodiment Explanatory drawing which shows the wavelength routing table of the wavelength router corresponding to the structure of the communication node of FIG. Explanatory drawing which shows the wavelength routing table of the wavelength router corresponding to the structure of the communication node of FIG. The figure which shows the other example of a detailed structure of the communication node in 4th Embodiment. Explanatory drawing which shows the wavelength routing table of the wavelength router corresponding to the structure of the communication node of FIG.

Explanation of symbols

  30a, 30b, 61: transmission signal, 62: reception signal, 701 to 708: optical transmission line, 100, 310, 410: wavelength multiplexed optical signal transmitter, 200, 320, 420: wavelength multiplexed optical signal receiver, 110, 311, 411: optical signal transmission circuit, 111: wavelength variable light source, 112 and 113: light emitting element, 114 and 215: switch circuit (electric switch), 115 and 214: optical switch, 120, 312 and 412: multiplexer, 121, 122, 313, 314, 413, 414: output port, 210, 321, 421: optical signal receiving circuit, 211, 212, 213: light receiving element (PD), 220, 322, 422: duplexer, 221, 222, 323, 324, 423, 424: input ports, 501 to 504: communication nodes, 601, 602: wavelength routers.

Claims (20)

N (N is an integer of 2 or more) optical signal transmission circuits that output M types of optical signals (M is an integer of 2 or more) according to the transmission signal, and M types of output from each circuit N optical signal transmission circuits set so as to constitute M sets of wavelength groups having different wavelengths,
N input ports to which the N optical signal transmission circuits are connected and M output ports to which M optical transmission lines are connected. The optical signals input from the input ports are A wavelength-multiplexed optical signal transmission apparatus comprising: a multiplexer that multiplexes optical signals having wavelengths belonging to a wavelength group and outputs the multiplexed signals to separate output ports. In the wavelength division multiplexing optical signal transmitter according to claim 1,
Each optical signal transmission circuit switches and outputs an optical signal having a wavelength belonging to each wavelength group among optical signals having M types of wavelengths corresponding to the transmission signal. In the wavelength division multiplexing optical signal transmitter according to claim 2,
Each optical signal transmission circuit comprises a wavelength variable light source that is driven by a transmission signal and can switch and output optical signals of M types of wavelengths. In the wavelength division multiplexing optical signal transmitter according to claim 2,
Each optical signal transmission circuit includes M light-emitting elements that can output optical signals of M types of wavelengths, and an optical switch that switches and outputs optical signals from the M light-emitting elements. Is a wavelength-division-multiplexed optical signal transmitter characterized by being switched and driven by a transmission signal. In the wavelength division multiplexing optical signal transmitter according to claim 2,
Each optical signal transmission circuit includes M light emitting elements each capable of outputting optical signals of M types of wavelengths, and optical couplers or optical filters that multiplex optical signals from the M light emitting elements. The wavelength-division-multiplexed optical signal transmission apparatus, wherein the light-emitting element is switched and driven by a transmission signal. In the wavelength division multiplexing optical signal transmitter according to claim 2,
Each optical signal transmission circuit includes M light-emitting elements that can output optical signals of M types of wavelengths, and an optical switch that switches and outputs optical signals from the M light-emitting elements. Is a wavelength-multiplexed optical signal transmitter characterized by being simultaneously driven by a transmission signal. In the wavelength division multiplexing optical signal transmitter according to claim 1,
Each optical signal transmission circuit simultaneously outputs optical signals of M types of wavelengths according to the transmission signal. In the wavelength division multiplexing optical signal transmitter according to claim 7,
Each optical signal transmission circuit includes M light emitting elements each capable of outputting optical signals of M types of wavelengths, and optical couplers or optical filters that multiplex optical signals from the M light emitting elements. The wavelength-multiplexed optical signal transmitter is characterized in that the light emitting elements are simultaneously driven by a transmission signal. In the wavelength division multiplexing optical signal transmitter according to any one of claims 1 to 8,
2. The wavelength division multiplexing optical signal transmission apparatus according to claim 1, wherein the multiplexer is composed of an arrayed waveguide diffraction grating having N inputs and M outputs. In the wavelength division multiplexing optical signal transmitter according to any one of claims 1 to 8,
2. The wavelength division multiplexing optical signal transmission apparatus according to claim 1, wherein the multiplexer comprises an N-input M-output circular array waveguide diffraction grating. M (N is an integer of 2 or more) optical signal receiving circuits that receive optical signals of M types of wavelengths (M is an integer of 2 or more) and output received signals. N types of wavelengths are set so as to constitute M sets of wavelength groups composed of different wavelengths, and N optical signal receiving circuits,
It has M input ports to which M optical transmission lines are connected and N output ports to which the N optical signal receiving circuits are connected, and belongs to each wavelength group input from each input port. A wavelength division multiplexing optical signal receiving apparatus comprising: a demultiplexer that demultiplexes an optical signal having a wavelength for each wavelength and outputs the demultiplexed optical signal to different output ports. The wavelength division multiplexing optical signal receiver according to claim 11,
Each optical signal receiving circuit includes a light receiving element capable of receiving optical signals of M types of wavelengths and outputting the received signals. The wavelength division multiplexing optical signal receiver according to claim 11,
Each optical signal receiving circuit receives optical signals of M types of wavelengths, and outputs M light receiving elements that can output the received signals, and light that switches and outputs the optical signals from the duplexer to the M light receiving elements. A wavelength-multiplexed optical signal receiver comprising: a switch; and a switch circuit that switches and outputs reception signals from M light receiving elements. The wavelength division multiplexing optical signal receiver according to claim 11,
Each optical signal receiving circuit receives optical signals of M types of wavelengths, and outputs M light receiving elements that can output the received signals, and light that switches and outputs the optical signals from the duplexer to the M light receiving elements. A wavelength multiplexed optical signal receiving apparatus comprising: a switch; and a coupling circuit that synthesizes and outputs reception signals from M light receiving elements. The wavelength division multiplexing optical signal receiver according to claim 11,
Each optical signal receiving circuit receives optical signals of M types of wavelengths, and outputs the M light receiving elements that can output the received signals and the optical signal from the duplexer to both of the M light receiving elements. An optical coupler or optical filter, and a switch circuit that switches and outputs received signals from M light receiving elements. The wavelength division multiplexing optical signal receiver according to claim 11,
Each optical signal receiving circuit receives optical signals of M types of wavelengths, and outputs the M light receiving elements that can output the received signals and the optical signal from the duplexer to both of the M light receiving elements. A wavelength-multiplexed optical signal receiver comprising: an optical coupler or an optical filter; and a coupling circuit that synthesizes and outputs received signals from M light receiving elements. In the wavelength division multiplexing optical signal receiver according to any one of claims 11 to 16,
2. The wavelength division multiplexing optical signal receiving apparatus according to claim 1, wherein the duplexer includes an arrayed waveguide diffraction grating having M inputs and N outputs. In the wavelength division multiplexing optical signal receiver according to any one of claims 11 to 16,
2. The wavelength division multiplexing optical signal receiving apparatus according to claim 1, wherein the duplexer includes a circular array waveguide diffraction grating having M inputs and N outputs. The wavelength division multiplexing optical signal transmission apparatus according to any one of claims 1 to 10,
A wavelength division multiplexing optical signal receiver according to any one of claims 11 to 18,
An optical wavelength division multiplexing communication system comprising M optical transmission lines capable of transmitting wavelength division multiplexed optical signals for connecting these devices. N communication nodes, M wavelength routers having N input ports and N output ports, and the communication nodes and wavelength routers are connected via N × M × 2 optical transmission lines. An optical wavelength division multiplexing communication system,
Each said communication node is comprised with the wavelength division multiplexing optical signal transmitter in any one of Claims 1 thru | or 10, and the wavelength division multiplexing optical signal receiver in any one of Claims 11 thru | or 18. Optical wavelength division multiplexing communication system.

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