JP2016225850A - Optical cross-connect device and optical module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical cross-connect device capable of reducing a probability of wavelength collision while using such a configuration that the wavelength collision may occur in principle, and an optical module.SOLUTION: The optical cross-connect device comprises: an optical switch function part for controlling transmission of an optical signal that is a wavelength multiplex signal, for M pieces of lines; and a conversion function part which includes α pieces of input ports or output ports and performs interconversion of a client signal and the optical signal. The optical switch function part includes at least one of a wavelength cross-connect function part for controlling a transmission destination of the optical signal between the lines and between the line and the conversion function part, an optical module that is configured by integrating K pieces of M×N wavelength selection switches, an optical module that is configured by integrating K pieces of N×M wavelength selection switches, and an optical module that is configured by integrating totally K pieces of M×N wavelength selection switches and N×M wavelength selection switches.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an optical cross-connect device and an optical module used in an optical network.

  2. Description of the Related Art Conventionally, an optical network composed of optical fibers that connect a plurality of optical nodes is known. FIG. 14 is a diagram illustrating a conventional optical network. The optical network 7 includes an optical cross-connect device (OXC) 8 that is an optical node, an optical fiber 3 that is an optical transmission line that connects the OXCs 8, and a client device 4 that is connected to each OXC 8. Prepare. When communication is performed between the client device 4 on the transmission side and the reception side, the optical network 7 transmits the signal of the client device 4 through the optical paths 5 and 6 between the transmission side OXC 8 and the reception side OXC 8. The transmission side OXC 8 is an OXC 8 connected to the transmission side client device 4. The reception side OXC 8 is an OXC 8 connected to the reception side client device 4.

FIG. 15 is a diagram illustrating functional blocks of the OXC 8 that can transmit and receive signals to M routes (M is a natural number of 2 or more).
The OXC 8 includes NNI (Network Node Interface) function units 81-1 to 81-M, 85-1 to 85-M, an optical switch function unit 82, and a UNI (User Network Interface) function unit 86. In the following description, reference numerals 81-1 to 81-M are denoted as 81-1 to M, and reference numerals 85-1 to 85-M are denoted as 85-1 to M. In the present specification, other symbols including “-” are also expressed in the same manner. The OXC 8 is connected to M input routes 301-1 to M and M output routes 302-1 to M including the optical fiber 3 connected in a specific direction.

  The NNI function units 81-1 to 81-M are provided corresponding to the M input routes 301-1 to 301-M, and wavelength division multiplexed signals (Wavelength Division Multiplexing signals) input from the input routes 301-1 to 301-M. : WDM signal) and optical path quality are monitored.

  The optical switch function unit 82 includes a WXC (Wavelength Cross-connect) function unit 83 and an Add / Drop function unit 84. The NNI function units 85-1 to 85-M are provided corresponding to the M output routes 302-1 to 302-1 to amplify the signal from the optical switch function unit 82 and monitor the optical path quality. The UNI function unit 86 has a function of terminating the optical path, and includes a plurality of transponders for accommodating a client signal in the optical signal.

  Next, details of the optical switch function unit 82 will be described. The WXC function unit 83 has a function of demultiplexing the WDM signal input from the NNI function units 81-1 to 81 -M, and switching of a transmission destination route for the demultiplexed optical signal (Cross-connect), It has a function of selecting extraction (Drop) and addition (Add). The Add / Drop function unit 84 has a function of receiving the extracted optical signal in the WXC function unit 83 and outputting it to the transponder of the UNI function unit 86. The Add / Drop function unit 84 has a function of outputting the optical signal added from the UNI function unit 86 to the WXC function unit 83.

  The WXC function unit 83 performs a process of demultiplexing the WDM signals input from the NNI function units 81-1 to 81-M for each wavelength, and transmits the demultiplexed optical signal to the destination path. Select whether to switch or take out. Here, when the switching of the transmission destination route is selected, the WXC function unit 83 multiplexes the WDM signals cross-connected from the input routes 301-1 to 301 -M, and converts the multiplexed WDM signal to the NNI. Output to the functional units 85-1 to 85-M. Accordingly, the NNI function units 85-1 to 85-M receive the optical signal output from the WXC function unit 83 and output the optical signals to the corresponding output routes 302-1 to 302-1. When the extraction is selected, the WXC function unit 83 outputs a WDM signal obtained by combining the extracted optical signals to the Add / Drop function unit 84.

  The Add / Drop function unit 84 outputs the WDM signal extracted by the WXC function unit 83 to the transponder of the desired UNI function unit 86. The transponder of the UNI function unit 86 converts the optical signal received from the Add / Drop function unit 84 from the signal format for wide-area transfer into the client signal that is the signal format used by the client device 4. And output to the client device 4. Here, the client signal is a signal corresponding to a communication standard such as 1 to 100 Gigabit Ethernet (registered trademark), OC-192, OC-48, STM64, and STM16.

  Further, when a new optical signal is added to the optical switch function unit 82, the transponder of the UNI function unit 86 converts the client signal from the client device 4 into an optical signal having a signal format for wide area transfer. The UNI function unit 86 outputs the optical signal converted by the transponder to the Add / Drop function unit 84. The Add / Drop function unit 84 receives the optical signal, switches it to be output from a desired NNI output port, and transmits it to the WXC function unit 83. The WXC function unit 83 multiplexes the optical signal received from the Add / Drop function unit 84 and the optical signal cross-connected to each route, and outputs the combined signal to the NNI function units 85-1 to 85-1.

  Next, a configuration example of a portion corresponding to one route in the WXC function unit 83 will be described. FIG. 16 is a diagram illustrating a configuration example of a portion corresponding to one route in the WXC function unit 83. L (L ≧ 2) shown in this figure is defined by L = M−1 + D, for example, where the number of routes is M. However, D is the number of Drop ports provided on the output side of the WSS (Wavelength Selective Switch) corresponding to the NNI function units 81-1 to 81-M of the WXC function unit 83, or the NNI function unit 85. The number of Add ports provided on the input side of the WSS on the output side corresponding to −1 to M.

  The 1 × L WSS 831 is one of M input-side WSSs provided corresponding to the NNI function units 81-1 to 81-1 and has one input port and L output ports. The L × 1 WSS 832 is one of M output-side WSSs provided corresponding to the NNI function units 85-1 to 85-1 M, and has L input ports and one output port. Note that instead of the 1 × L WSS 831, a 1 × L optical coupler that is an optical coupler having L output ports may be used.

  The 1 × L WSS 831 demultiplexes the WDM signal input from the corresponding one of the NNI function units 81-1 to 81-M for each wavelength, and the transmission destination of the demultiplexed optical signal. The route is switched or picked up. Next, the 1 × L WSS 831 obtains a WDM signal by combining the optical signals subjected to optical switch processing according to the selection, and the WDM signal is added to the output side WSS of the Add / Drop function unit 84 or another route. To L × 1 WSS (not shown).

  The L × 1 WSS 832 multiplexes the WDM signal output from the 1 × L WSS constituting the WSS on the input side of another route and the WDM signal output from the Add / Drop function unit 84, and the NNI function unit Output to the corresponding one of 85-1 to 85-M.

  Next, a configuration example of the Add / Drop function unit 84 will be described. FIG. 17 is a diagram illustrating a configuration example of the Add / Drop function unit 84. The Add / Drop function unit 84 inputs the WDM signal extracted from the WSS on the input side to a desired transponder, so that the M × 1 WSS 841 having M input ports and one output port, and one input port And 1 × N1 optical coupler 842 having N1 (N1 ≧ 2) output ports.

  The M × 1 WSS 841 has an input port connected to the drop port of the WSS on the input side including the 1 × L WSS 831, and combines the WDM signals extracted from the WSSs on the input side to 1 × N1 optical coupler To 842.

  The 1 × N1 optical coupler 842 branches the WDM signal input from the M × 1 WSS 841 and outputs it to each transponder of the UNI function unit 86. Here, when the transponder of the UNI function unit 86 has a local transmission light source, the frequency of the optical signal received by each transponder among the WDM signals is selected according to the frequency of the local transmission light, so that the 1 × N1 optical coupler 842 The output WDM signal is directly input to the transponder. When the transponder of the UNI function unit 86 does not have a local light source, the 1 × N1 optical coupler 842 is used to select the frequency of the optical signal received by each transponder among the WDM signals output from the 1 × N1 optical coupler 842. And an optical device having wavelength selectivity such as a variable wavelength filter is inserted between the transponder and the transponder.

  The Add / Drop function unit 84 is configured to input the WDM signal output from the transponder to the WSS on the output side, and has N1 × 1 light having N1 (N1 ≧ 2) input ports and one output port. A coupler 844 and a 1 × M WSS 843 having one input port and M output ports are provided. The N1 × 1 optical coupler 844 has N1 input ports connected to each transponder, combines the WDM signals output from the transponders, and outputs the combined WDM signal to the 1 × M WSS 843. The 1 × M WSS 843 demultiplexes the WDM signal input from the N1 × 1 optical coupler 844 into optical signals for each wavelength, and multiplexes the demultiplexed optical signals for each output-side WSS to be added. To generate a WDM signal. Next, the 1 × M WSS 843 outputs the generated WDM signal to the corresponding output-side WSS.

JP 2010-81374 A

P. Palacharla, X. Wang, I. Kim, D. Bihon, MD Feuer, SL Woodward, “Blocking Performance in Dynamic Optical Networks based on Colorless, Non-directional ROADMs”, in Optical Fiber Communication Conference / National Fiber Optic Engineers Conference (OFC / NFOEC) 2011, JWA8. R. Younce, S. Gringeri, Y. Wang, J. Larikova, “Contentionless and Near Contentionless Blocking Performance and Economics for All Coherent Metro / Regional Networks”, in Optical Fiber Communication Conference (OFC) 2014, W4B.5.

In the configuration of the Add / Drop function unit 84 shown in FIG. 17, when optical signals having the same wavelength are simultaneously extracted from a plurality of WSSs on the input side, if they are multiplexed in the M × 1 WSS 841, collision of optical signals ( Hereinafter, there is a problem of occurrence of wavelength collision).
And in order to avoid such a wavelength collision, the optical cross-connect apparatus which has the function (henceforth a contentionless function) which prevents a wavelength collision within an optical cross-connect apparatus is proposed (for example, (See Non-Patent Document 2.) Here, consider a case where the technology of the Add / Drop function unit described in Non-Patent Document 2 is applied to the Add / Drop function unit 84 shown in FIG. FIG. 18 is a diagram illustrating a first configuration example of the Add / Drop function unit that realizes the contentionless function.

  As shown in FIG. 18, the Add / Drop function unit 84a is configured as an M × N1 multicast switch including a Drop function unit 84a1 and an Add function unit 84a2. The drop function unit 84a1 includes M 1 × N1 optical couplers 84a1-1 to 84a1-1 to N1 having N1 branches, and N1 M × 1 optical switches 84a1 having M input ports and one output port. 4-6 are provided. The output port of each 1 × N1 optical coupler 84a1-1-3 and the input port of each M × 1 optical switch 84a1-4-6 are connected. A WDM signal extracted from the WSS on the input side is input to the input port of each 1 × N1 optical coupler 84a1-1-3, and the output port of each M × 1 optical switch 84a1-4-6 is connected to each transponder. Is done.

Another configuration example of the Add / Drop function unit that realizes the contentionless function will be described. FIG. 19 is a diagram illustrating a second configuration example of the Add / Drop function unit for realizing the contentionless function.
As shown in FIG. 19, the Add / Drop function unit 84b has an M × N1 contentionless WSS 84b1, which is a WSS having M input ports and N1 output ports, and has an optical system configuration in which wavelength collision does not occur. N1 × M contentionless WSS84b2 which is WSS of N1 ports and M output ports. The input port of the M × N1 contentionless WSS 84b1 receives the WDM signal extracted from the WSS on the input side. The output port of the N1 × M contentionless WSS84b2 is connected to the WSS on the output side.

  Here, problems of the Add / Drop function unit that realizes the contentionless function shown in FIGS. 18 and 19 will be described. The Add / Drop function unit 84a shown in FIG. 18 can avoid the wavelength collision, but has a principle loss due to the optical coupler, so that the loss is high and an optical amplifier is required. For this reason, there is a problem that the number of parts increases and the configuration of the apparatus becomes complicated. In addition, the Add / Drop function unit 84b shown in FIG. 19 is technically difficult to actually manufacture the M × N1 contentionless WSS84b1 and the N1 × M contentionless WSS84b2 as products, There is a problem that it is difficult to mass-produce.

  In view of the above circumstances, an object of the present invention is to provide an optical cross-connect device and an optical module that can reduce the probability of wavelength collision, in principle, using a configuration in which wavelength collision occurs.

  One embodiment of the present invention includes an optical switch function unit that controls transmission of an optical signal that is a wavelength multiplexed signal, and α input ports for M (M is a natural number of 2 or more) paths. An optical cross-connect device that performs conversion from an optical signal to a client signal or a conversion function unit that has α output ports and performs conversion from a client signal to an optical signal, the optical switch function unit The wavelength cross-connect function unit that controls the transmission destination of the optical signal between the routes and between the route and the conversion function unit, and the transmission / reception between the wavelength cross-connect function unit and the conversion function unit In order to process the optical signal, an M × N wavelength selective switch, which is a wavelength selective switch having M input ports and N (N is a natural number of 2 or more) output ports, K (K is 2 More natural numbers) An optical module in which K N × M wavelength selective switches, which are wavelength selective switches having N input ports and M output ports, are integrated, and the M × N wavelength selective switch and the N × An optical cross-connect device including at least one of K optical modules integrated with an M wavelength selective switch.

  One aspect of the present invention is the optical cross-connect device, in which the optical module controls a duplexer that demultiplexes an optical signal, and a reflection direction of the optical signal that is demultiplexed by the duplexer. Either or both of the optical switch units are shared by the K wavelength selective switches.

  One aspect of the present invention is the optical cross-connect device, wherein the optical module includes a plurality of planar lightwave circuits having K input / output ports.

  One aspect of the present invention is the optical cross-connect device, in which the planar lightwave circuit is provided when the optical module has a function corresponding to the M × N wavelength selective switch or the N × M wavelength selective switch. M + N are provided.

  One aspect of the present invention is the optical cross-connect device described above, wherein in the optical module, the value of N of the M × N wavelength selective switch or the N × M wavelength selective switch is N ≦ 20.

  One aspect of the present invention is the optical cross-connect device, wherein the conversion function unit further includes a function of transmitting / receiving the client signal to / from any of a plurality of client devices, and the output port of the conversion function unit And a first connection selection unit that connects any of the client devices, or a second connection selection unit that connects the client device and an input port of any of the conversion function units.

  One aspect of the present invention is the optical cross-connect device, wherein the conversion function unit is arranged in units of N input ports or output ports corresponding to the optical module. The connection selection unit connects the N output ports of the conversion function unit of the same unit and the different client devices, respectively, and the second connection selection unit includes a plurality of connections from the same client device. The output is connected to the input port of the conversion function unit of the different unit.

  One aspect of the present invention is the optical cross-connect device, wherein the M × N wavelength selective switch and a third connection selection unit that connects an optical path between an arbitrary input port of the conversion function unit, And a fourth connection selection unit that connects an optical path between the output port of the conversion function unit and any of the N × M wavelength selective switches.

  One aspect of the present invention is the optical cross-connect device, wherein the conversion function unit is arranged in units of N input ports or output ports corresponding to the optical module, The connection selection unit connects N outputs of the same M × N wavelength selective switch and N input ports of the conversion function unit of different units, respectively, and the fourth connection selection unit includes: N output ports of the same conversion unit of the same unit are connected to different N × M wavelength selective switches.

  One embodiment of the present invention includes an optical switch function unit that controls transmission of an optical signal that is a wavelength multiplexed signal, and α input ports for M (M is a natural number of 2 or more) paths. Provided in the optical switch function unit of an optical cross-connect device that performs conversion from an optical signal to a client signal or a conversion function unit that has α output ports and performs conversion from a client signal to an optical signal. An optical module comprising: M input ports and N (N is a natural number of 2 or more) output ports for processing the optical signal transmitted between the path and the conversion function unit. A configuration in which K (K is a natural number of 2 or more) M × N wavelength selective switches having a configuration, a configuration in which K N × M wavelength selective switches having N input ports and M output ports are integrated, And the M × N wavelength selective switch It is an optical module having at least one of the configurations in which K pieces are integrated together with the N × M wavelength selective switch.

  One aspect of the present invention is the optical module, further comprising: a demultiplexer that demultiplexes the optical signal; and an optical switch unit that controls a reflection direction of the optical signal demultiplexed by the demultiplexer. And at least one of the duplexer and the optical switch unit is shared by K wavelength selective switches.

  One embodiment of the present invention is the above-described optical module, which includes a plurality of planar lightwave circuits each having K input / output ports.

  According to the present invention, in an optical cross-connect device and an optical module corresponding to a plurality of routes, the probability of wavelength collision can be reduced while using a configuration in which wavelength collision occurs in principle.

It is a figure which shows the outline of the optical network in this embodiment. It is a figure which shows the functional block of OXC2 in this embodiment. It is a figure which shows the structural example of the optical switch function part 21 in this embodiment. It is a figure which shows the structural example of the drop side optical module 22a which integrated K M × N WSS in 1st Embodiment. It is a figure which shows the structural example of 2 * 3 WSS, and the example of control of the optical signal by the switch element of 2 * 3 WSS. It is a figure which shows the structural example using the planar lightwave circuit by using several MxN WSS in 2nd Embodiment as an optical module. It is a figure which shows the detailed structural example of the optical input / output part 61 shown in FIG. 6 in 2nd Embodiment. It is a graph which shows the relationship between the port number N of the M * N WSS in the optical module in 3rd Embodiment, and the probability that a wavelength collision will occur in OXC2. It is a figure which shows the structural example of the UNI function part 86 periphery in 4th Embodiment. It is a graph which shows the relationship between the presence or absence of the WSS selection parts 91 and 92 in 4th Embodiment, and the probability that a wavelength collision will occur in OXC2. It is a figure which shows the structural example of the UNI function part 86 periphery in 5th Embodiment. It is a figure which shows the structural example of the UNI function part 86 periphery in 6th Embodiment. It is a figure which shows an example of the wiring of WSS selection part 91b, 92b. It is a figure which shows the conventional optical network. It is a figure which shows the functional block of OXC8 which can transmit / receive a signal with respect to M (M is a natural number more than 2) path | route. 5 is a diagram illustrating a configuration example of a portion corresponding to one route in a WXC function unit 83. FIG. 5 is a diagram illustrating a configuration example of an Add / Drop function unit 84. FIG. It is a figure which shows the 1st structural example of the Add / Drop function part which implement | achieves a contentionless function. It is a figure which shows the 2nd structural example of the Add / Drop function part which implement | achieves a contentionless function.

Embodiments of the present invention will be described below with reference to the drawings.
(Configuration common to the first to sixth embodiments)
FIG. 1 is a diagram showing an outline of an optical network in the present embodiment. The optical network 1 shown in FIG. 1 is different from the conventional optical network 7 shown in FIG. 14 in that the optical network 1 includes an OXC 2 that is an optical cross-connect device having a different configuration from the OXC 8 shown in FIG. Since the other structure which has attached | subjected the code | symbol is the same, description is abbreviate | omitted.

FIG. 2 is a diagram showing functional blocks of the OXC 2 in the present embodiment.
2 is different from the conventional OXC 8 shown in FIG. 15 in that the optical switch function unit 21 includes an Add / Drop function unit 22, and the other components are denoted by the same reference numerals. Since the configuration of is the same, description thereof is omitted. The optical switch function unit 21 includes a WXC function unit 83 and an Add / Drop function unit 22.

  The WXC function unit 83 performs selection of transmission destination route switching (Cross-connect), extraction (Drop), and addition (Add), and controls the transmission destination of the optical signal. The Add / Drop function unit 22 outputs the WDM signal extracted by the WXC function unit 83 to the transponder of the UNI function unit 86, and outputs the WDM signal added from the transponder of the UNI function unit 86 to the WXC function unit 83. The UNI function unit 86 is a function unit (conversion function unit) that performs bidirectional conversion between an optical signal and a client signal.

  Next, the operation of OXC2 will be described. The NNI function units 81-1 to 81-M amplify the WDM signals input from the respective input routes 301-1 to 301-M and output them to the WXC function unit 83. The WXC function unit 83 performs a process of demultiplexing the WDM signals input from the NNI function units 81-1 to 81-M for each wavelength, and transmits the demultiplexed optical signal to the destination path. Select whether to switch or take out.

  Here, when switching of the destination route is selected, the WXC function unit 83 multiplexes the WDM signals cross-connected to the respective routes, and the multiplexed WDM signal is transmitted to the NNI function unit 85-1 to 85-1. Output to M. The NNI function units 85-1 to 85-M receive the optical signals output from the WXC function unit 83 and output the optical signals to the corresponding output routes 302-1 to 302-1. When the extraction is selected, the WXC function unit 83 outputs a WDM signal obtained by combining the extracted optical signals to the Add / Drop function unit 22. As a result, the Add / Drop function unit 22 outputs the received WDM signal to a desired transponder of the UNI function unit 86.

  Further, when a new optical signal is added to the optical switch function unit 21, the transponder of the UNI function unit 86 converts the client signal from the client device 4 into an optical signal having a signal format for wide area transfer. The UNI function unit 86 outputs the optical signal converted by the transponder to the Add / Drop function unit 22. The Add / Drop function unit 22 receives the optical signal, switches it to be output from a desired NNI output port, and transmits it to the WXC function unit 83. The WXC function unit 83 multiplexes the optical signal received from the Add / Drop function unit 22 and the optical signal cross-connected from each input path 301-1 to M to the NNI function unit 85-1 to 85 -M. Output.

Next, the detail of the structure of the optical switch function part 21 in this embodiment is demonstrated. FIG. 3 is a diagram illustrating a configuration example of the optical switch function unit 21 in the present embodiment.
The optical switch function unit 21 shown in FIG. 3 shows a configuration example in the case of corresponding to three input / output paths (M = 3). The WXC function unit 83 includes one input port and L output ports of 1 × L WSSs 831-1 to 83, and L input ports and one output port of L × 1 WSSs 832-1 to 83-3. The WXC function unit 83 receives the WDM signal input from the NNI function units 81-1 to 81-1M as one of L × 1 WSS 832-1 to 3 installed corresponding to the output routes 302-1 to M, or , A process of branching to the drop side optical module 22a is performed. Note that at least one of each 1 × L WSS 831-1 to 3 may be replaced with a 1 × L optical coupler that is an optical coupler having L output ports. Note that the number of input / output ports of the optical coupler to be replaced is preferably the same as the number of input / output ports of the WSS to be replaced.

The Add / Drop function unit 22 includes M × N including M input ports M (M is a natural number of 2 or more) and N output ports N (N is a natural number of 2 or more) WSSs (K is a natural number of 2 or more). A configuration including a drop-side optical module 22a in which WSSs 22a-1 to K are integrated, and an add-side optical module 22b in which N × M WSSs 22b-1 to K including N input ports and M output ports are integrated. It is.
The drop side optical module 22 a receives the WDM signal output from the 1 × L WSSs 831-1 to 83-1 and outputs it to a desired transponder of the UNI function unit 86. The add-side optical module 22b outputs the WDM signal (including a single wavelength) input from the transponder of the UNI function unit 86 to any one of L × 1 WSS 832-1 to 3 corresponding to a desired output path. .

  FIG. 3 shows a configuration in which one drop-side optical module 22a and one add-side optical module 22b are arranged. However, the number of drop-side optical modules 22a and one add-side optical module 22b is as follows. There may be a plurality.

  In FIG. 3, L is 1 from the sum of the product of the number K of M × N WSSs 22a-1 to K in the drop-side optical module 22a and the number X of drop-side optical modules 22a and the number of routes M. It is a subtracted natural number (L = M + K × X−1). N is the number of ports on the UNI function unit 86 side in the M × N WSSs 22a-1 to K in the drop-side optical module 22a. M is the number of ports on the WXC function unit 83 side in the M × N WSSs 22a-1 to K in the drop-side optical module 22a, and is equal to the number M of routes. In addition, the number of input ports of a single drop-side optical module 22a in which K M × N WSSs are integrated is equal to the product of M and K, and the number of output ports is equal to the product of N and K. Similarly, the number of input ports of a single add-side optical module 22b in which K N × M WSSs are integrated is equal to the product of N and K, and the number of output ports is equal to the product of M and K.

  In the drop-side optical module 22a, M × N WSSs 22a-1 to K integrated in the drop-side optical module 22a receive WDM signals including the same wavelength from a plurality of input ports among the M input ports. In such a case, a configuration may be adopted in which wavelength collision occurs inside. Alternatively, a combination of M × N WSS and N × M WSS may be integrated and integrated, and the drop-side optical module 22a and the add-side optical module 22b may be realized by one optical module. The M × N WSS configured to cause wavelength collision inside the WSS has M × 1 WSS with M input ports and one output port, and 1 × N WSS with one input port and N output ports. This is optically and functionally equivalent to a configuration in which an output port of M × 1 WSS and an input port of 1 × N WSS are connected.

Next, the operation of the optical switch function unit 21 shown in FIG. 3 will be described.
First, an operation related to extraction in the optical switch function unit 21 will be described. The WDM signals input from the NNI function units 81-1 to 81-M corresponding to the input paths 301-1 to 301-M are demultiplexed for each wavelength by the 1 × L WSS 831-1 to 3 which are WSSs on the input side. . The 1 × L WSSs 831-1 to 3-1 generate the WDM signal by combining the demultiplexed optical signal for each output port corresponding to the switching destination route or the extraction destination. The WDM signal branched in this way is either L × 1 WSS 832-1 to WSS832-1 to 3 corresponding to the output side corresponding to each path, or M × N of the drop side optical module 22a corresponding to the extraction destination. It is output to any one of WSSs 22a-1 to K. The drop-side optical module 22a obtains an optical signal obtained by demultiplexing the WDM signal received from the 1 × L WSS 831-1 to -3 for each wavelength, and outputs the optical signal to each corresponding transponder of the UNI function unit 86. .

Next, an operation related to addition in the optical switch function unit 21 will be described.
The add-side optical module 22 b obtains an optical signal input from the transponder of the UNI function unit 86. Next, the add-side optical module 22b multiplexes the optical signal for each L × 1 WSS 832-1 to 3 corresponding to the output destination, and the multiplexed WDM signal is any of the L × 1 WSS 832-1 to L-3. To output. The L × 1 WSS 832-1 to 3 multiplex the WDM signal received from the 1 × L WSS 831-1 to 3 and the WDM signal received from the Add-side optical module 22b to the NNI function units 85-1 to 85-1M. Output.

  As described above, the feature of the configuration of the Add / Drop function unit 22 of the OXC 2 of this embodiment is that M × N WSSs are integrated compared to the configuration of the Add / Drop function unit 84 shown in FIG. The drop-side optical module 22a or the add-side optical module 22b in which K N × M WSSs are integrated is used. A configuration in which a plurality of M × N WSSs are arranged in the Add / Drop function unit 22 in the case where optical signals having the same wavelength are included in a plurality of WDM signals input from 1 × L WSSs 831-1 to 831-1. The points superior to the Add / Drop function unit 84 shown in FIG. 17 will be described. With the configuration of the Add / Drop function unit 22, the probability that a plurality of WDM signals including optical signals having the same wavelength are input to the same M × N WSS is reduced. That is, it is possible to reduce the probability that wavelength collision occurs in the Add / Drop function unit in the optical cross-connect device.

  The drop-side optical module 22a and the add-side optical module 22b of the add / drop function unit 22 are configured to integrate a plurality of WSSs into one module. Thereby, the Add / Drop function unit 22 can be reduced in size. That is, the optical cross-connect device including the Add / Drop function unit 22 can be downsized to reduce the installation area.

  Next, specific configuration examples of an optical module in which a plurality of WSSs are integrated, such as the drop-side optical module 22a or the add-side optical module 22b shown in FIG. 3, will be described as first to third embodiments. .

(First embodiment)
First, a first embodiment of an optical module in which a plurality of M × N WSSs are integrated will be described.
FIG. 4 is a diagram illustrating a configuration example of the drop-side optical module 22a in which K M × N WSSs are integrated in the first embodiment. FIG. 4 shows a configuration example of the drop-side optical module 22a when K = 3, M = 1, and N = 2.

  The drop-side optical module 22a includes light input units 41-1 to 41-3 such as a collimator, light output units 42-11 to 32 such as a collimator, a diffraction grating 43, lenses 44-1 to 43, and a switch element. 45. In the drop-side optical module 22a in which K M × N WSSs are integrated, M × K (three in FIG. 4) optical input units 41-1 to 3-3 are installed, and the optical output units 42-11 to 32 are N × K (six in FIG. 4) are installed. The diffraction grating 43 divides and reflects the WDM signals input from the optical input units 41-1 to 4-3 by diffracting and reflecting them at different angles depending on the wavelength, and is reflected by the switch element 45. The optical signals output to the optical output units 42-11 to 32 are multiplexed. The lenses 44-1 to 44-3 propagate the optical signal demultiplexed by the diffraction grating 43 to a predetermined region of the switch element 45, and transmit the optical signal whose deflection angle is controlled by the switch element 45 to the predetermined value of the diffraction grating 43. Propagate to the area.

  The switch element 45 includes K (three in FIG. 4) switch elements 45-1 to 45-3, and the optical signal demultiplexed by the diffraction grating 43 is output to an arbitrary optical output unit 42-11 for each wavelength. In order to input to 32, the beam deflection angle of the optical signal is controlled. Specifically, the switch element 45-1 performs control to input the optical signal demultiplexed by the diffraction grating 43 to any one of the light output units 42-11 and 42-12 for each wavelength. -2 performs control to input the optical signal demultiplexed by the diffraction grating 43 to one of the light output units 42-21 and 42-22 for each wavelength. The switch element 45-3 is controlled by the diffraction grating 43. Control is performed to input the demultiplexed optical signal to one of the optical output units 42-31 and 42-32 for each wavelength.

  In FIG. 4, one M × N WSS includes, for example, an optical input unit 41-1, optical output units 42-11 and 42-12, a diffraction grating 43, a lens 44-1, and a switch element 45-1. It consists of and. K M × N WSSs are stacked side by side in the y-axis direction. In addition, the light input parts 41-1 to 3 and the light output parts 42-11 to 32 are configured by, for example, fiber collimators. The switch element 45 is made of, for example, LCOS (Liquid Crystal on Silicon).

  Next, the configuration of an optical system for integrating a plurality of WSSs into one module, such as the drop-side optical module 22a shown in FIG. Spatial separation of the plurality of WSS optical systems by arranging the plurality of WSS light input units 41-1 to 4-3 and light output units 42-11 to 32 in the direction of the y-axis in FIG. Can do. At this time, the optical input units 41-1 to 41-1 and the optical output units 42-11 to 32 corresponding to the input / output ports of each WSS have the incident optical signals in the same region of the diffraction grating 43 and the switch element 45. It arrange | positions so that it may inject. Note that the drop-side optical module 22a in FIG. 4 has a configuration in which one diffraction grating 43 and one switch element 45 are shared by a plurality of WSSs. The drop side optical module 22a may have a configuration in which one of the one diffraction grating 43 and one switch element 45 is shared by a plurality of WSSs.

  Further, in the drop side optical module 22a of FIG. 4, a configuration example in which three 1 × 2 WSSs are integrated is shown. The configuration of FIG. 4 can also be applied to the configuration. That is, by using the same optical system member as in FIG. 4 and changing the arrangement and control method of some optical system members, an optical module in which a plurality of M × N WSSs with M and N being 2 or more are integrated is obtained. It is possible to realize. A configuration example of M × N WSS for realizing an optical module in which a plurality of M × N WSSs having M and N of 2 or more are integrated will be described below.

A configuration example of M × N WSS for realizing an optical module in which a plurality of M × N WSSs having M and N of 2 or more will be described.
FIGS. 5A and 5B are diagrams illustrating a configuration example of 2 × 3 WSS when M = 2 and N = 3 and an example of optical signal control by a switching element of 2 × 3 WWS.

  The 2 × 3 WSS in FIGS. 5A and 5B includes an optical input unit 41-11 provided corresponding to the first input port and an optical input unit 41 provided corresponding to the second input port. -12, an optical output unit 42-11 provided corresponding to the first output port, an optical output unit 42-12 provided corresponding to the second output port, and corresponding to the third output port The optical output part 42-13 provided and the switch element 45-1 which reflects the optical signal input from the optical input parts 41-11-12 to either of the optical output parts 42-11-13 are provided. 5A and 5B, the diffraction grating 43 and the lens 44-1 are omitted.

  In the 2 × 3 WSS of FIG. 5A, the optical signal from the first input port is coupled to the switch element 45-1 via the optical input unit 41-11. The optical signal input to the switch element 45-1 is demultiplexed by the diffraction grating 43 and becomes an optical signal for each wavelength. The switch element 45-1 is an optical signal from the first input port, and the optical signal demultiplexed for each wavelength is output to the optical output units 42-11 corresponding to the first to third output ports for each wavelength. The beam deflection angle of the optical signal is controlled so as to be coupled to any one of 13. In the example of FIG. 5A, the switch element 45-1 transmits an optical signal having a specific wavelength obtained by demultiplexing the optical signal from the first input port to the optical output unit 42-11 corresponding to the first output port. Reflect toward you.

  Next, in FIG. 5B, an example of control of the switch element when an optical signal is input from a second input port different from the first input port of FIG. In the 2 × 3 WSS of FIG. 5B, the optical signal from the second input port is coupled to the switch element 45-1 via the optical input unit 41-12. The switch element 45-1 is an optical signal from the second input port, and the optical output unit 42-11 corresponding to the first to third output ports for each wavelength of the optical signal demultiplexed for each wavelength. The beam deflection angle of the optical signal is controlled so as to be coupled to any one of 13. In the example of FIG. 5B, the switch element 45-1 sends an optical signal having a specific wavelength obtained by demultiplexing the optical signal from the second input port to the optical output unit 42-13 corresponding to the third output port. The reflection direction is controlled so as to reflect the light toward the screen.

  Thus, as shown in FIGS. 5A and 5B, the beam deflection control corresponding to each input port and output port pair is realized by the switch element 45, whereby the 1 × 2 WSS shown in FIG. The M × N WSS in which M and N are 2 or more can be realized with the same configuration as the configuration of the optical system. Accordingly, the optical module may be configured to share the optical system members such as the diffraction grating 43 and the switch element 45 in a plurality of M × N WSSs by the same configuration as the configuration of the optical system shown in FIG. it can. Furthermore, the drop-side optical module 22a in which K pieces of M × N WSSs are integrated can be realized by performing beam deflection control in the switch element 45-1 as shown in the examples of FIGS. 5 (a) and 5 (b). It becomes possible.

(Second Embodiment)
Next, a modification of the optical module in which a plurality of M × N WSSs are integrated will be described as a second embodiment.
FIG. 6 is a diagram illustrating a configuration example using a planar lightwave circuit using a plurality of M × N WSSs as optical modules in the second embodiment. 6 outputs an optical signal from each input port to the optical system of the optical module 60, or outputs an optical signal from the optical system of the optical module 60 to an output port. A diffraction grating 43, a lens 62, and a switch element 45. The optical input / output unit 61 includes a planar lightwave circuit such as a quartz-based planar lightwave circuit (PLC) that performs processing such as branching and coupling of optical signals.

The optical module 60 in FIG. 6 is mainly different from the drop-side optical module 22a shown in FIG. 4 in the following points.
(1) The shape of the light input / output unit 61 is changed to have a plurality of input ports or output ports.
(2) Instead of the configuration including the optical input units 41-1 to 4-3 and the optical output units 42-11 to 32, the configuration includes a planar lightwave circuit. (3) A plurality of installed in each integrated WSS The point which becomes a structure corresponding to several WSS with the single lens 62 instead of the structure provided with the lenses 44-1.

Next, a detailed configuration example of the light input / output unit 61 illustrated in FIG. 6 will be described.
FIG. 7 is a diagram illustrating a detailed configuration example of the light input / output unit 61 illustrated in FIG. 6. As shown in FIG. 7, the optical input / output unit 61 includes an input / output port 601 including a plurality of input / output waveguides, and a plurality of slab waveguide units 602 each connected to K input / output ports. And an arrayed waveguide 603 and a slab waveguide 604. The plurality of slab waveguide portions 602 having K input / output ports are constituted by a planar lightwave circuit.

  The optical module 60 shown in FIG. 7 includes three slab waveguide portions 602. This indicates that the value of M + N in the M × N WSS built in the optical module 60 is 3. That is, when the optical module 60 has a function corresponding to M × N WSS, the optical module 60 includes M + N slab waveguide portions 602. Therefore, it can be said that the optical module 60 shown in FIG. 7 includes 1 × 2 WSS. In the three waveguides 601-1 included in the input / output port 601, an optical signal is input to one, and an optical signal is output from the two. Each slab waveguide 602 shown in FIG. 7 is connected to two waveguides 601-1 and 601-2. This indicates the number of M × N WSSs built in the optical module 60. Therefore, it can be said that the optical module 60 shown in FIG. 7 includes two 1 × 2 WSSs.

  Note that the slab waveguide 602 is not limited to the configuration shown in FIG. 7, and has one or more input ports and one or more output ports. It is sufficient if the number of the total is K.

  In the slab waveguide unit 602 alone, the traveling direction of the optical signal output from the slab waveguide unit 602 differs for each optical signal input from each input port of the slab waveguide unit 602. The light input / output unit 61 can also integrate a plurality of slab waveguides 602. As shown in FIG. 7, when a plurality of slab waveguides 602 are integrated in one optical input / output unit 61, optical signals input from input ports having the same port number in each slab waveguide 602 are as follows: At the output port of each slab waveguide 602, the signals are output in the same traveling direction. As a result, the optical signal input from each input port of the same M × N WSS is input to the input port having the same port number of each slab waveguide unit 602, so that K M × N WSSs are input. These optical systems can be realized by spatially separating them.

  As shown in FIG. 7, by configuring the slab waveguide 602 with a planar lightwave circuit having a plurality of input ports and output ports, it is possible to use a planar lightwave circuit miniaturization technique. That is, the optical input / output unit 61 can be miniaturized and integrated in the input / output ports increased by the number of M × N WSSs included in the optical module 60.

(Third embodiment)
Next, a modification of the optical module in which a plurality of M × N WSSs are integrated will be described as a third embodiment.
This embodiment shows a preferable value for the number of ports on the UNI function unit 86 side of each WSS in the optical module in which a plurality of M × N WSSs are integrated in the Add / Drop function unit 22.

  FIG. 8 is a graph showing the relationship between the number N of M × N WSS ports in the optical module according to the third embodiment and the probability that a wavelength collision will occur in OXC2. This graph is a graph showing the result of evaluating the relationship between the number of M × N WSSs in the optical module and the probability that wavelength collision occurs in the OXC 2 by computer simulation. This evaluation was performed on the Add / Drop function unit 22 included in the OXC2 alone shown in FIG. Specifically, first, whether wavelength collision occurs inside the drop side optical module 22a and the add side optical module 22b, or all the transponders in the UNI function unit 86 of the OXC2 are used, or all paths of the optical node A model is set in which only an optical path is added (no path is released) until any of the following events occurs. Next, the probability when a wavelength collision occurs inside the OXC 2 and the path setting is completed is obtained. In the evaluation, the optical path opening request to the OXC 2 was evaluated by changing the ratio of the number of Add / Drop optical path requests and the number of Through optical path requests.

  The conditions set for the evaluation are as follows. First, it is assumed that the number of routes to which the OXC 2 to be evaluated is connected is 4, and the number of transponders in the UNI function unit 86 of the entire OXC 2 is 40. For both Add / Drop traffic and Through traffic, the probability of occurrence follows a Poisson distribution. When setting an optical path, the optical path is set in which path, and the optical path signal is input to which M × N WSS. Each of them was decided at random. The number of transponders in the UNI function unit 86 is the number of K M × N WSS in the drop-side optical module 22a and K number of N × M WSS in the add-side optical module 22b on the UNI function unit 86 side. Equal to the sum of the numbers.

  Next, the evaluation result of the computer simulation shown in the graph of FIG. 8 will be described. In FIG. 8, the horizontal axis represents the ratio of the number of Add / Drop path requests and Through path requests arriving at a single optical node. The vertical axis represents the ratio of the number of times that the path setting is completed due to the occurrence of wavelength collision in OXC2 with respect to 100,000 trials. In addition, cases of 10, 20, and 40 are shown as the number of transponders per M × N WSS in the drop side optical module 22a.

  In the graph of FIG. 8, the evaluation results indicated by dotted lines are the results when the number of transponders per M × N WSS is 10 (the number of M × N WSSs K = 4, N = 10). The evaluation results indicated by broken lines are the results when the number of transponders per M × N WSS is 20 (the number of M × N WSSs K = 2, N = 20). For comparison, the solid line shows the results when using one M × N WSS in which wavelength collision occurs internally (the number of transponders per M × N WSS is 40, N = 40).

  As shown in FIG. 8, as the number K of M × N WSSs in the optical module increases and the number of transponders per M × N WSS (= the number N of ports of M × N WSS) decreases, It can be seen that it is possible to reduce the probability of occurrence of wavelength collision in the connect device. Here, the number N of ports on the UNI function unit 86 side of each M × N WSS in an optical module in which a plurality of M × N WSSs are integrated (hereinafter simply referred to as “the number N of ports of each M × N WSS”) is appropriate. The upper limit will be described.

First, the upper limit of the number N of ports of each M × N WSS in the case of a small-scale optical transmission system provided with about 15 optical cross-connect devices will be described. In such an optical transmission system, the probability that a wavelength collision will occur in one optical cross-connect device in the optical transmission system is 1/15 = 7 × 10 ⁻² . Therefore, the probability of occurrence of wavelength collision that can ignore wavelength collision in the optical cross-connect device is considered to be about 1/5 of the probability 7 × 10 ⁻² that wavelength collision occurs in the optical cross-connect device. Here, when the number N of ports per M × N WSS is 40, referring to the graph of FIG. 8, the probability that a wavelength collision will occur in the optical cross-connect device is about 6 × 10 ⁻² . This probability is a probability that the occurrence of wavelength collision cannot be ignored at the optical node in the optical transmission system. On the other hand, assuming that the number of ports N per M × N WSS is 20 by dividing into K = 2, the probability of wavelength collision occurring in the optical cross-connect device is about 5 × 10 ⁻³ from the graph of FIG. It is possible to suppress. In other words, in the case of a small-scale optical transmission system in which about 15 optical cross-connect devices are deployed, the number of transponders per M × N WSS is set to 20, so that wavelength collisions in the optical cross-connect device occur. The probability can be suppressed to a level at which the occurrence of wavelength collision can be ignored.

Next, the upper limit of the number N of ports of each M × N WSS in the case of a large-scale optical transmission system provided with about 200 optical cross-connect devices will be described. In such an optical transmission system, the probability that a wavelength collision occurs in one optical cross-connect device in the optical transmission system is 1/200 = 5 × 10 ⁻³ . Therefore, the probability of occurrence of wavelength collision that can ignore wavelength collision in the optical cross-connect device is considered to be about 1/5 of the probability of wavelength collision occurring in the optical cross-connect device, 5 × 10 ⁻³ . Here, when the number N of ports per WSS is 20, referring to the graph of FIG. 8, the probability that a wavelength collision will occur in the optical cross-connect device is about 5 × 10 ⁻³ . This probability is a probability that the occurrence of wavelength collision cannot be ignored at the optical node in the optical transmission system. On the other hand, if the number of ports N per M × N WSS is set to 10 by dividing K = 4, it is possible to suppress the probability of wavelength collision in the optical cross-connect device to about 1 × 10 ^−3. (See graph in FIG. 8). That is, in the case of a large-scale optical transmission system in which about 200 optical cross-connect devices are deployed, the number of transponders per M × N WSS is set to 10, so that wavelength collisions in the optical cross-connect device occur. The probability can be suppressed to a level at which the occurrence of wavelength collision can be ignored.

As described above, the value of the number N of ports of each M × N WSS has a predetermined probability of wavelength collision in the optical cross-connect device according to the number of optical cross-connect devices arranged in the optical transmission system. It is preferable to set to be smaller than the threshold value. The same applies to the number N of ports on the UNI function unit 86 side of each N × M WSS in an optical module in which a plurality of N × M WSSs on the Add side are integrated.
In the above description, the probability that a wavelength collision occurs in the optical cross-connect device is 1 / (the optical cross-connect device included in the optical transmission system as a condition that the occurrence of the wavelength collision can be ignored in the optical node in the optical transmission system. However, the present invention is not limited to this. For example, a condition that 1 / (the number of optical cross-connect devices included in the optical transmission system) is a threshold value and is smaller than the threshold value may be used.

(Fourth embodiment)
Next, a configuration in which a WSS selection unit is provided between the UNI function unit 86 and the client device 4 will be described as the OXC 2 of the fourth embodiment. The WSS selector is connected to any WSS in the drop-side optical module 22a in which M × N WSSs 22a-1 to K are integrated, or in the add-side optical module 22b in which N × M WSSs 22b-1 to K are integrated. Has a function to select.

  FIG. 9 is a diagram illustrating a configuration example around the UNI function unit 86 of the OXC 2 according to the fourth embodiment. As shown in FIG. 9, between the UNI function unit 86 and the client apparatus 4, a WSS selection unit 91 that selects connection with an arbitrary M × N WSS in the drop-side optical module 22a, and an add-side optical module 22b A WSS selection unit 92 that selects a connection with any N × M WSS. The UNI function unit 86 includes transponder units 86 a-1 to 86 a-1 to K and three transponder units 86 b-1 to 86 K that accommodate three transponders. In the UNI function unit 86, transponder units 86a-1 to 86a-1 to K are provided corresponding to the M × N WSSs 22a-1 to K, respectively, and the transponder units 86b-1 are respectively corresponding to the N × M WSSs 22b-1 to K. ~ K are provided. Since one transponder unit that accommodates three transponders corresponds to one WSS, the number of output ports of one WSS is three.

  In FIG. 9, the configuration within the optical switch function unit 21 including the Add / Drop function unit 22 is the same as the configuration illustrated in FIG. 3, and the configuration other than the Add / Drop function unit 22 is omitted. doing.

  The WSS selection unit 91 has a function of connecting each of the transponders in the transponder units 86a-1 to 86a-1K in the UNI function unit 86 to an arbitrary client device 4. The WSS selection unit 92 has a function of connecting each client apparatus 4 to any transponder in the transponder units 86b-1 to 86b-1 to K in the UNI function unit 86. The WSS selectors 91 and 92 are configured by, for example, a matrix SW (switch) or a combination of selectors.

  The OXC 2 includes WSS selection units 91 and 92, thereby outputting client signals from the transponders in the transponder units 86 a-1 to K in the UNI function unit 86 to an arbitrary client device 4, and each client. The client signal from the device 4 can be output to any transponder in the transponder units 86b-1 to 86K in the UNI function unit 86. Each transponder in the UNI function unit 86 is connected to one of M × N WSSs 22 a-1 to K and N × M WSSs 22 b-1 to K in the Add / Drop function unit 22. Therefore, the WSS selection unit 91 can connect each M × N WSS 22 a-1 to K to any client device 4 by selecting any client device 4. Similarly, the WSS selection unit 92 connects each client apparatus 4 to any N × M WSS in the N × M WSS 22b-1 to K by selecting any transponder in the UNI function unit 86. be able to.

  Hereinafter, the effect when the OXC 2 is configured to include the WSS selection units 91 and 92 will be described with a specific example. As described above, by providing the WSS selection unit 91, any M × N WSS in the M × N WSSs 22 a-1 to K connected to each client device 4 is selected as an optical path route accommodating the client signal. can do.

  For example, when setting an optical path, when a certain M × N WSS in the M × N WSSs 22 a-1 to K is selected and the optical path cannot be set due to a wavelength collision, the WSS selection unit 92 The connection can be switched to another M × N WSS. Thereby, the probability of the wavelength collision which generate | occur | produces in OXC2 can be lowered | hung by selecting another MxN WSS.

  Furthermore, a case where traffic (optical path setting request) is concentrated on the client apparatus 4 connected to a certain M × N WSS among the M × N WSSs 22a-1 to K will be described. In the absence of the WSS selectors 91 and 92, wavelength collision is likely to occur in the M × N WSS corresponding to the client apparatus 4 in which traffic is concentrated. However, the WSS selectors 91 and 92 can avoid the concentration of signals on one M × N WSS or N × M WSS by selecting connection destinations in the order according to round robin, etc., and the probability of wavelength collision Can be lowered.

Here, in the above-described configuration of OXC2, the result of evaluating the relationship between the number of M × N WSSs in the optical module and the probability of occurrence of wavelength collision in OXC2 by computer simulation will be described using a graph.
FIG. 10 is a graph showing the relationship between the presence / absence of the WSS selectors 91 and 92 and the probability that a wavelength collision occurs in the OXC 2 in the fourth embodiment. In this evaluation, the WSS selection units 91 and 92 are not adopted, and the optical path is allocated in the M × N WSS 22a-1 until the transponder of the transponder unit 86a-1 connected to the M × N WSS 22a-1 is used up. When all the transponders of the transponder unit 86a-1 are used, the transponder unit 86a-2 connected to the M × N WSS 22a-2 is added and the M × N WSS 22a-2 is used until the transponder unit 86a-2 is used up. In the case where the optical path is allocated by sequentially increasing the transponder units connected to the M × N WSSs 22a-1 to K as in the case of performing the optical path allocation, When selecting WSS or N × M WSS in the order according to round robin, within OXC2 A comparative evaluation of the probability that the length collision occurs went. Other simulation settings / conditions are the same as the simulation settings / conditions of the graph shown in FIG. FIG. 10 shows the results when the number of transponders per M × N WSS is 10 or 20 with or without the WSS selection units 91 and 92. The evaluation results indicated by the dotted lines are the results when the WSS selection units 91 and 92 are provided and the number of transponders per M × N WSS is 10, and the evaluation results indicated by the broken lines are the WSS selection units 91. , 92 and the number of transponders per M × N WSS is 20. On the other hand, the evaluation result indicated by the alternate long and short dash line is the result when the number of transponders per M × N WSS is 10 without the WSS selection unit, and the evaluation result shown in practice is the WSS selection This is a result in the case where the number of transponders per M × N WSS is set to 20.

  From the graph of FIG. 10, under the condition where the number of transponders per M × N WSS is the same, the use of the WSS selectors 91 and 92 can reduce the probability of wavelength collision in OXC2. Thus, by providing the WSS selectors 91 and 92, it is possible to reduce the probability that a wavelength collision occurs in the OXC2.

(Fifth embodiment)
Next, as the OXC2 of the fifth embodiment, the drop side optical module 22a in which M × N WSSs 22a-1 to K are integrated between the UNI function unit 86 and the client device 4 or the N × M WSS 22b— A configuration in which a WSS selection unit that selects connection with different WSSs in the add-side optical module 22b in which 1 to K are integrated will be described.
FIG. 11 is a diagram illustrating a configuration example around the UNI function unit 86 of the OXC 2 in the fifth embodiment. As shown in FIG. 11, between the UNI function unit 86 and the client device 4, a different M × N WSS in the drop side optical module 22 a and a WSS selection unit 91 a that connects one client device 4, respectively. Each client apparatus 4 includes a WSS selection unit 92a that connects different N × M WSSs in the add-side optical module 22b.

  OXC2 shown in FIG. 11 is different from OXC2 shown in FIG. 9 in that it includes WSS selectors 91a and 92a, and the other configurations are the same. The WSS selection unit 91a connects the plurality of output ports of each transponder unit 86a-1 to K to different client devices 4. The WSS selection unit 92 a connects a plurality of output ports of the same client device 4 to different transponder units 86 b-1 to 86 b -K in the UNI function unit 86. The wiring of the WSS selection units 91a and 92a is, for example, a wiring of a medium capable of transmitting a client signal.

  The WSS selectors 91a and 92a send a plurality of client signals transmitted and received by the same client device 4 to one transponder unit 86a-1 to another transponder unit 86a-1 to 86K and a transponder unit 86b in the UNI function unit 86, respectively. One transponder unit can be selected and input / output from −1 to K. In addition, the transponder units 86a-1 to 86a-1 to K in the UNI function unit 86 are arranged and connected to correspond to the M × N WSSs 22a-1 to K in the drop side optical module 22a. Therefore, when signals from the M × N WSSs 22 a-1 to K are converted into client signals by the transponder units 86 a-1 to K, client signals from different M × N WSSs 22 a-1 to K are transmitted to the same client device 4. Entered. Similarly, the transponder units 86b-1 to 86b-1 to K in the UNI function unit 86 are arranged and connected corresponding to the N × M WSSs 22b-1 to K in the Add-side optical module 22b. Therefore, a plurality of client signals output from the same client device 4 can be client signals input to different N × M WSSs 22b-1 to K, respectively.

  Hereinafter, an effect when the OXC 2 is configured to include the WSS selection units 91a and 92a will be described with a specific example. For example, in a certain optical network, a case is assumed in which a small number of client devices are introduced and then client devices are added in response to an increase in traffic demand. In this case, if all the signals of one client device are connected to the same M × N WSS, the optical path settings are concentrated on one M × N WSS, so that wavelength collision is likely to occur.

  However, by providing the WSS selectors 91a and 92a, it is possible to connect each input port or output port of one client device 4 to different M × N WSSs. Similarly, each input port or output port and a different M × N WSS are connected to the added client device 4. Further, according to an increase in traffic demand (increase in the number of optical paths), the M × N WSS and the client device 4 can be connected in an order corresponding to round robin. Thereby, it is possible to avoid concentration of optical paths to one M × N WSS, and to reduce the probability of occurrence of wavelength collision.

(Sixth embodiment)
Next, as the OXC 2 of the sixth embodiment, a configuration in which a WSS selection unit is provided between the Add / Drop function unit 22 and the UNI function unit 86 will be described. The WSS selection unit is an optical signal from any M × N WSS in the drop side optical module 22a in which M × N WSSs 22a-1 to K are integrated, or an add side light in which N × M WSSs 22b-1 to K are integrated. It has a function of selecting an optical signal to an arbitrary N × M WSS in the module 22b.

  FIG. 12 is a diagram illustrating a configuration example around the UNI function unit 86 of the OXC 2 in the sixth embodiment. As shown in FIG. 12, between the Add / Drop function unit 22 and the UNI function unit 86, M × N WSSs 22a-1 to 22K-1 in the drop-side optical module 22a, and any transponder in the UNI function unit 86, Are connected to each other, a WSS selection unit 92b for connecting a transponder in the UNI function unit 86, and an arbitrary N × M WSS in the Add-side optical module 22b.

  The WSS selector 91b has a function of connecting an optical path from the M × N WSSs 22a-1 to K in the drop side optical module 22a to an arbitrary transponder in the transponders 86a-1 to 86K in the UNI function unit 86. . The WSS selection unit 92b has a function of connecting an optical path from each transponder of the transponder units 86b-1 to 86b-1 to K in the UNI function unit 86 to any N × M WSSs 22b-1 to K in the Add-side optical module 22b. Have. The WSS selectors 91b and 92b can be realized by a combination of an optical fiber and an optical switch.

  Hereinafter, the effect when the OXC 2 is configured to include the WSS selection units 91b and 92b will be described with a specific example. By providing the WSS selectors 91b and 92b, an optical path terminated (transmitted / received) by each transponder in the UNI function unit 86 can be any optical path in the drop-side optical module 22a or the add-side optical module 22b. An optical path connected to the WSS can be selected. As a result, when an optical path cannot be set due to the occurrence of a wavelength collision when an optical path is set and a wavelength collision occurs, another M * N WSS is switched by switching the WSS selector 91b. You can choose. That is, the probability that a wavelength collision will occur inside OXC2 can be reduced.

  Further, a case will be described in which wavelength collisions in the corresponding M × N WSS are likely to occur due to the concentration of optical path setting requests to specific transponders in the UNI function unit. For example, by selecting different M × N WSSs in the order of round robin or the like in the WSS selection unit 91b, it is possible to avoid the concentration of optical paths to specific M × N WSSs. Thereby, the probability that a wavelength collision will occur inside OXC2 can be lowered.

  In addition, as a method of setting a plurality of optical paths that terminate in the transponder included in the same transponder unit in the UNI function unit 86 shown in FIG. 12, each transponder of the same transponder unit and the drop-side optical module 22a or Add There is a method of setting an optical path that connects different WSSs in the side optical module 22b. The wiring of the WSS selection units 91b and 92b at this time can be realized by wiring of a medium capable of transmitting an optical signal. An example of the wiring of the WSS selectors 91b and 92b is shown in FIG. The effect in this case is the same as the effect of the fifth embodiment shown in FIG. For example, even in the case where a small number of transponders of the UNI function unit 86 are introduced at the initial stage and the transponders of the UNI function unit 86 are added in response to an increase in traffic demand, M × N WSS can be selected in the round robin order. Concentration on one M × N WSS can be avoided. Thereby, the probability that a wavelength collision will occur inside OXC2 can be lowered.

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and includes designs and the like that do not depart from the gist of the present invention.

  An optical cross-connect device and an optical module according to the present invention are devices incorporated in an optical node in an optical network composed of an optical fiber and an optical node connected between the optical fibers. For example, it is suitable as a device for controlling a transmission destination of a multiplexed optical signal such as a WDM signal transmitted.

DESCRIPTION OF SYMBOLS 1, 7 ... Optical network, 2 ... Optical cross-connect apparatus, 3 ... Optical fiber, 4 ... Client apparatus, 21, 82 ... Optical switch function part, 81-1 to 81-M, 85-1 to 85-M ... NNI Function part, 83 ... WXC function part, 22, 84 ... Add / Drop function part, 22a ... Drop side optical module, 22b ... Add side optical module, 41-1 to 41-3 ... Light input part, 42-11 to 42 -32 ... optical output unit, 43 ... diffraction grating, 44-1 to 44-3, 62 ... lens, 45, 45-1 to 45-3 ... switch element, 60 ... optical module, 61 ... optical input / output unit, 602 ... Slab waveguide part, 86 ... UNI function part, 301-1 to 301-M ... Input route, 302-1 to 302-M ... Output route, 831-1 to 831-3 ... 1 x L WSS, 832 1~832-3 ... L × 1 WSS, 86a-1~86a-K, 86b-1~86b-K ... transponder, 91,91a, 91b, 92,92a, 92b ... WSS selector

Claims (12)

For M (M is a natural number greater than or equal to 2) paths, an optical switch function unit that controls transmission of an optical signal that is a wavelength multiplexed signal, and α input ports, from the optical signal to the client signal An optical cross-connect device including a conversion function unit that performs conversion, or has α output ports and performs conversion from a client signal to an optical signal,
The optical switch function unit is
A wavelength cross-connect function unit that controls a transmission destination of the optical signal between the routes and between the route and the conversion function unit;
A wavelength having M input ports and N (N is a natural number of 2 or more) output ports for processing the optical signal transmitted and received between the wavelength cross-connect function unit and the conversion function unit. N × M wavelength selection switch, which is a wavelength selection switch having K (where K is a natural number of 2 or more) integrated optical modules, N input ports, and M output ports. An optical cross-connect device comprising: an optical module in which K switches are integrated; and at least one of an optical module in which the M × N wavelength selective switch and the N × M wavelength selective switch are integrated together.   The optical module selects K wavelengths, either or both of a demultiplexer that demultiplexes an optical signal and an optical switch unit that controls the reflection direction of the optical signal demultiplexed by the demultiplexer. The optical cross-connect device according to claim 1, which is shared by switches.   The optical cross-connect device according to claim 1, wherein the optical module includes a plurality of planar lightwave circuits having K input / output ports.   The optical cross-connect device according to claim 3, wherein the optical module includes M + N planar lightwave circuits as a configuration that realizes a function equivalent to the M × N wavelength selective switch or the N × M wavelength selective switch.   5. The optical cross-connect device according to claim 1, wherein a value of N of the M × N wavelength selective switch or the N × M wavelength selective switch is N ≦ 20 in the optical module. The conversion function unit further includes a function of transmitting / receiving the client signal to / from one of a plurality of client devices,
A first connection selection unit that connects an output port of the conversion function unit and an arbitrary client device, or a second connection unit that connects the client device and an input port of an arbitrary conversion function unit. The optical cross-connect device according to any one of claims 1 to 5, further comprising a connection selection unit. The conversion function unit is arranged in units of N input ports or output ports corresponding to the optical module,
The first connection selection unit connects the N output ports of the conversion function unit of the same unit and the different client devices, respectively.
The optical cross-connect device according to claim 6, wherein the second connection selection unit connects a plurality of outputs from the same client device and input ports of the conversion function units of different units. A third connection selection unit for connecting an optical path between the M × N wavelength selective switch and an input port of an arbitrary conversion function unit;
The optical cross according to any one of claims 1 to 5, further comprising a fourth connection selection unit that connects an optical path between the output port of the conversion function unit and any of the N × M wavelength selective switches. Connect device. The conversion function unit is arranged in units of N input ports or output ports corresponding to the optical module,
The third connection selection unit connects N outputs of the same M × N wavelength selective switch and N input ports of the conversion function unit of different units, respectively.
9. The optical cross-connect device according to claim 8, wherein the fourth connection selection unit connects N output ports of the conversion function unit of the same unit and the different N × M wavelength selective switches. For M (M is a natural number greater than or equal to 2) paths, an optical switch function unit that controls transmission of an optical signal that is a wavelength multiplexed signal, and α input ports, from the optical signal to the client signal An optical module provided in the optical switch function unit of an optical cross-connect device that performs conversion or includes a conversion function unit that has α output ports and performs conversion from a client signal to an optical signal,
M × N wavelength selection having M input ports and N (N is a natural number of 2 or more) output ports for processing the optical signal transmitted between the path and the conversion function unit A configuration in which K switches (K is a natural number of 2 or more) are integrated, a configuration in which K N × M wavelength selective switches having N input ports and M output ports are integrated, and the M × N An optical module comprising at least one of a configuration in which a total of K wavelength selective switches and N × M wavelength selective switches are integrated. A demultiplexer for demultiplexing an optical signal;
An optical switch for controlling the reflection direction of the optical signal demultiplexed by the demultiplexer,
The optical module according to claim 10, wherein at least one of the duplexer and the optical switch unit is shared by K wavelength selective switches.   The optical module according to claim 10 or 11, comprising a plurality of planar lightwave circuits having K input / output ports.

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