JP2013183371A - Optical identification regeneration device and optical path switching device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve problems that, if a regenerative repeater supporting each intermediate band transmission rate is prepared for regenerative repeating optical signals of many intermediate transmission bands, development cost and operation and management cost increase, and that although there is another approach of using a regenerative repeater capable of changing its transmission rate, those kinds of regenerative repeaters need a high performance for regenerating a signal of a transmission rate of the maximum capacity, and if this repeater is used for regenerating an optical signal of lower transmission rate, regenerative repeating cost per bit increases.SOLUTION: There are provided an optical identification regeneration device having a function of identification regenerative repeating an optical signal which is deteriorated during transmission, an optical path switching device having the same, an optical identification regeneration device especially having means for identification regenerating one or more wavelength multiplex optical signals of various transmission rates, and a band variable optical path switching device having the optical identification regeneration device.

Description

  The present invention relates to an optical identification / reproduction device having a function of identifying and repeating an optical signal deteriorated by transmission, and an optical path switching device equipped with the same, and in particular, one or a plurality of wavelength-multiplexed lights having various transmission rates. The present invention relates to an optical identification / reproduction device including means for identifying and reproducing a signal and a band-variable optical path switching device including the same.

  Commercial introduction of wavelength division multiplexing networks has been started that utilizes wavelength division multiplexing transmission technology in optical fiber transmission technology to associate optical signal wavelengths with transmission / reception destinations and realize multipoint-to-multipoint optical communication. Such an optical wavelength multiplexing network connects optical path switching devices called ROADMs (Reconfigurable Optical Add Drop Multiplexers) and WXCs (Wavelength Cross-connect devices) with optical fibers. Thus, a ring-shaped or mesh-shaped optical wavelength division multiplexing network is constructed.

  The transmission loss of the optical fiber is compensated by an optical amplifier. A client signal of a client communication device such as a router is converted into an optical signal suitable for transmission on an optical network, and also has a function of converting a received optical signal into a client signal, via an optical communication device called an optical transponder. And connected to the optical path switching device. In an optical path switching device, wavelength-multiplexed optical signals are wavelength-separated, edited for each destination, and wavelength-multiplexed to perform optical communication between any client communication devices connected to the optical wavelength-multiplexed network. Realized.

  Optical signals in an optical wavelength division multiplexing network that is currently commercially introduced are arranged on a frequency grid specified by ITU-T, and the interval between the center frequencies of adjacent optical signals is constant, for example, 100 GHz. . In addition, the optical transport network (OTN) standardized by ITU-T has four transmission rates of 2.5 Gb / s (OTU1), 10 Gb / s (OTU2), 40 Gb / s (OTU3), and 100 Gb / s (OTU4). Is stipulated. Here, OTU is an abbreviation for Optical channel Transport Unit, and is a transfer frame in which management information and an error correction code are added to a client signal in order to transfer the client signal with high reliability by OTN.

  The quality of individual optical signals passes through optical fibers, optical amplifiers, and optical path switching devices in multiple stages, which degrades the waveform and signal-to-noise ratio. Therefore, the required signal quality is required for large-scale optical networks. In order to secure the optical signal, the optical signal that needs to be identified and reproduced out of the wavelength multiplexed optical signal is branched by the optical path switching device and input to the optical identification and reproduction device to perform waveform shaping and signal-to-noise ratio recovery. After you have inserted into the optical network.

  FIGS. 15 to 17 are diagrams for explaining a conventional method for realizing identification reproduction when the optical path switching device is ROADM. For simplicity, only one direction is shown. FIG. 15 is a functional block of a conventional optical path switching device with an optical identification / reproduction device, FIG. 16 is an example of a spectrum in each unit, and FIG. 17 is a functional block of the conventional optical identification / reproduction device. The input optical signal of the optical identification / reproduction device 153 is once converted into an electric signal by the optical receiving unit 1531 and converted into a digital signal by threshold processing, and then the frame processing unit 1532 performs code error correction and management information processing. Thereafter, the optical transmission unit 1533 converts the electrical signal into an optical signal and outputs it.

  On the other hand, in order to accommodate optical signals with different bit rates and optical signals with different transmission distances more efficiently from the viewpoint of frequency utilization efficiency, the center frequency interval between adjacent optical signals is set as a requirement of each optical signal. Elastic optical path networks that are appropriately adjusted according to the proposal have been proposed (see, for example, Patent Documents 1 and 2 and Non-Patent Documents 1 and 2). In the elastic optical path network, the transmission rate in finer units such as 10 Gb / s, 20 Gb / s, 30 Gb / s,... 90 Gb / s, 100 Gb / s is set according to the actual transmission capacity between client devices. to support.

  As a method for realizing such a transfer frame for transferring the intermediate band client signal, a plurality of existing OTUs are concatenated (for example, three OTU2s are concatenated to provide a transmission rate of 30 Gb / s), and A method of newly defining an OTU in an intermediate band (for example, defining a new frame that provides a transmission rate of 30 Gb / s and expressing it as OTU23 or the like) has been studied (Non-Patent Document 3). In addition, a super channel technique has been proposed as a technique for generating and receiving a large-capacity optical signal without being limited by the speed of an electronic circuit (for example, Non-Patent Document 4). In this technology, on the transmission side, optical subchannel signals generated by a plurality of low-speed optical transmitters are multiplexed in the optical frequency domain to form a superchannel signal, which is collectively switched as a unit within the optical network. On the receiving side, the super channel is separated into the original low-speed optical signal and received by a plurality of low-speed optical receivers. The bit rate and occupied band of the super channel can be appropriately adjusted by changing the number of optical subchannels constituting the superchannel, the symbol rate of each optical subchannel, and the number of bits per symbol.

Japanese Patent Application No. 2008-241773 Japanese Patent Application No. 2009-212148

Masahiko Kanno, Hidehiko Takara, Bartolomelko Sitsuki "Dynamic and Band-Scalable Optical Network and its Realization Technology" IEICE Japanese Journal Vol. J93-B No. 3, pp. 403-411, 2010. M.M. Jinno, H .; Takara, B.A. Kozicki, Y .; Tsukishima, Y .; Sone, and S.M. Matsuoka, “Spectrum-Efficient and Scalable Optical Path Network: Architecture, Benefits, and Enabling Technologies,” IEEE Commun. Mag. , Vol. 47, Issue 11, pp. 66-73, 2009. M.M. Jinno, T .; Ohara, Y. et al. Sone, A.M. Hirano, O .; Ishida, and M.I. Tomizawa, “Elastic and Adaptive Optical Networks: Possible Adoption Scenarios and Future Standardization Aspects,” IEEE Communications Mags. 49, Issue. 10, pp. 164-172, 2011. Gabriella Bosco, Andrea Carena, Vittorio Curri, Pierluigi Poggiolini, and Fabrizio Forghieri, "Performance Limits of Nyquist-WDM and CO-OFDM in High-Speed PM-QPSK Systems," IEEE PHOTONICS TECHNOLOGY LETTERS, VOL. 22, NO. 15, AUGUST 1, 2010. H. Sanjoh, E .; Yamada, and Y.K. Yoshikuni, “Optical ortho frequency division multiplexing using frequency / time domain filtering for high spectral efficiency up to 1 Hz”, Yoshikuni, “Optical ortho frequency division multiplexing using frequency / time domain filtering for high spectral efficiency up to 1 Hz. OFC 2002, ThD1 (2002) G. Baxter et al. , "Highly Programmable Wavelength Selective Switch Based on Liquid Crystal on Silicon Switching Elements," Proc. OFC / NFOEC 2006, OTuF2, 2006. S. Griinger, et al. "Flexible Architectures for Optical Transport Nodes and Networks," IEEE Commun. Mag. , Vol. 48, Issue. 7, pp. 40-50, 2010.

  In the current optical wavelength division multiplexing network system, the transmission rate employed by the system is usually at most two types (for example, 40 Gb / s and 100 Gb / s). There are at most two types. On the other hand, in an elastic optical path network, it is necessary to regenerate and repeat optical signals with many intermediate band transmission rates.

  As an approach to achieve this, it is conceivable to prepare regenerative repeaters corresponding to each intermediate band transmission rate. Development costs and management operation costs increase because they must be managed together. Another approach is to use a regenerative repeater that can change the transmission rate, but such a regenerative repeater must have high performance to regenerate the signal of the maximum capacity transmission rate, When used for regeneration of an optical signal with a low transmission rate, there is a disadvantage that the processing capacity of the remaining capacity is wasted and the regeneration relay cost per bit is expensive.

  The present invention has been made in view of the above points, and provides an optical identification / reproduction device including means for identifying and reproducing one or a plurality of wavelength-multiplexed optical signals having various transmission rates, and an optical path switching device including the same. The purpose is to provide it economically.

  In order to solve the above problems, an optical identification / reproduction apparatus according to the present invention selectively selects one or more wavelength-division-multiplexed optical signals into N and one optical subchannel in the branched optical signal. N optical subchannel identifying and reproducing means for receiving and outputting as identified and reproduced optical subchannels, and means for combining and outputting the identified and reproduced optical subchannels, and deteriorated due to transmission One or a plurality of wavelength multiplexed optical signals are identified and reproduced and output.

  Also, the optical identification / reproduction apparatus of the present invention corrects and outputs a code error included in the identified signal.

  Also, the wavelength of the selectively received optical subchannel is converted into another wavelength and output.

  In addition, the optical identification / reproduction apparatus of the present invention converts the modulation format of the selectively received optical subchannel into another modulation format and outputs it.

  Furthermore, the optical path switching apparatus of the present invention is connected to the optical identification / reproduction apparatus at the branch port, the output thereof is connected to the insertion port, and only the signals that require identification / regeneration relay among the input wavelength multiplexed optical signals. Is reproduced and output to the required output port.

  According to the optical identification and reproduction apparatus of the present invention, one or a plurality of wavelength multiplexed optical signals to be input are each composed of one or a plurality of optical subchannels, and the total of those optical subchannels is N or less. Thus, it becomes possible to identify and reproduce an arbitrary number of wavelength multiplexed optical signals having an arbitrary transmission rate (the number of optical subchannels), which could not be realized by the prior art.

  According to the optical identification / reproduction device of the present invention, there are provided an optical identification / reproduction device including means for identifying and reproducing one or a plurality of wavelength-multiplexed optical signals having various transmission rates, and an optical path switching device including the same. Can do.

It is 1 of the structural example of the basic functional block of the optical identification reproducing | regenerating apparatus in the 1st Embodiment of this invention. An example of a spectrum of the first embodiment of the present invention, (a) shows the optical signal _{L B, L C1 ~L C4,} L E, (b) shows the optical signal _{L D1,} (c) _{Represents the} optical signal L _D2 , (d) represents the optical signal L _D3 , and (e) represents the optical signal L _D4 . It is 2 of the structural example of the basic functional block of the optical identification reproducing | regenerating apparatus in the 1st Embodiment of this invention. An example of a spectrum of the first embodiment of the present invention, (a) shows the optical signal _{L B0, L B1, L B2} , (b) shows the optical signal _{L C1,} (c) an optical signal _Lc2 is shown, (d) shows the optical signal _LC3 , and (e) shows the optical signal _LC4 . It is an example of the spectrum in the 1st Embodiment of this invention, (a) shows the optical signal L _D1 , (b) shows the optical signal L _D2 , (c) shows the optical signal L _D3 , ( d) shows the optical signal L _D4 , (e) shows the optical signal L _E1 , (f) shows the optical signal L _E2 , and (g) shows the optical signal L _E0 . FIG. 5 is a functional block when a shared frame processing unit is installed in the optical identification reproducing apparatus according to the first embodiment of the present invention. FIG. It is 1 of the structural example of the optical path switching apparatus in the 2nd Embodiment of this invention. An example of a spectrum in one of the second configuration example of the optical path switching device in an embodiment of the present invention, (a) shows an input wavelength-multiplexed optical signal L _A, the (b) is branched optical signal L _B1 shown, (c) shows a branch optical signal _{L B2,} indicating the (d) shows the output wavelength-multiplexed optical signal _{L G.} It is 2 of the structural example of the optical path switching apparatus in the 2nd Embodiment of this invention. It is 3 of the structural example of the optical path switching apparatus in the 2nd Embodiment of this invention. An example of a wavelength conversion in the present invention, (a) shows the optical signal L _B, indicating the (b) the optical signal L _E. An example of a modulation format conversion of the optical signal in the present invention, (a) shows the optical signal L _B, indicating the (b) the optical signal L _E. An example of a coupling of the frequency slots in the present invention, (a) shows the optical signal L _B, indicating the (b) the optical signal L _E. An example of the separation of the optical signal in the present invention, (a) shows the optical signal L _B, indicating the (b) the optical signal L _E. It is a basic functional block of a conventional optical path switching device with an optical identification reproducing device. The spectrum of each part of the conventional optical regenerator equipped optical path switching device, (a) shows the input wavelength-multiplexed optical signal L _A, (b) shows the optical signal L _B1, (c) the optical signal L shows the _B2, (d) shows the output wavelength-multiplexed optical signal _{L G.} It is a basic functional block of a conventional optical identification reproducing apparatus.

Embodiments of the present invention will be described below with reference to the drawings.
[First Embodiment]
FIG. 1 is a diagram for explaining basic functional blocks of the optical identification reproducing apparatus according to the first embodiment of the present invention. The optical identification / reproduction device of this embodiment shown in FIG. 1 includes a 1: N optical branching unit 10, N optical subchannel identification / reproduction units 20, and an N: 1 optical multiplexing unit 30. Here, N is an integer of 2 or more, for example, about 4 to 10. In the figure, the case where N is 4 is described.

  Each optical subchannel identification / reproduction unit 20 includes an optical subchannel selection reception unit 21, a threshold processing unit 22, a frame processing unit 23, and an optical subchannel transmission unit 24.

Examples of the input optical signal L _B, as shown in the spectrum diagram of FIG. 2 (a), the considered optical signals 1 and 2. Here, the optical signal 1 is a super channel with a total transmission rate of 300 Gb / s in which three optical subchannels of 100 Gb / s are arranged adjacent to each other, and the optical signal 2 is composed of one optical subchannel of 100 Gb / s. This is a super channel with a total transmission rate of 100 Gb / s (a special case where the number of optical subchannels is 1). These input optical signal _{L B} is 1: N optical branching unit 10, is divided into N optical signal _L C1 _{~L C4} is input to the optical sub-channel reproducing unit 20.

  In each optical subchannel identifying / reproducing unit 20, the optical subchannel selective receiving unit 21 selectively receives only one optical subchannel among the optical subchannels constituting the optical signal 1 and the optical signal 2, Convert to electrical signal.

  For selective reception of the optical subchannel, for example, a coherent optical reception technique can be used. Specifically, after the coherent reception is performed by matching the center frequency of the local light with the center frequency of the optical subchannel to be selectively received, an electric filter having a passband equal to the band of the optical subchannel is used. What is necessary is just to remove an optical subchannel component. In addition to such a homodyne reception technique, a heterodyne reception technique or an intradyne reception technique may be used. When the super channel has no spectrum overlap between the optical sub-channels, only the optical sub-channel may be extracted using an optical filter having a band equal to the optical sub-channel desired to be selectively received. If the optical orthogonal frequency domain multiplexing (optical OFDM) technology with spectral overlap between optical subchannels is adopted as a super channel multiplexing method, an optical filter and an optical gate are used in addition to the coherent reception technology. Thus, selective reception of the optical subchannel may be performed using a method of performing Fourier transform in the optical domain. A method for such optical OFDM reception is described in detail in Non-Patent Document 5, for example.

Each optical subchannel signal converted into an electrical signal by selective reception is converted into a digital signal by the threshold processing unit 22, and then the frame processing unit 23 performs section monitoring for code error correction, alarm monitoring / quality monitoring, etc. Management information processing is performed. Then, after being converted into an optical signal by the optical subchannel transmission unit 24, as shown in FIGS. 2B to 2E, it is output as optical subchannel signals L _{D1 to} L _D4 that are identified and reproduced. . Thereafter, each optical sub-channel signal _L D1 _{~L D4} is, N: at 1 optical multiplexer 30, are wavelength-multiplexed output optical signal _{L E} is output.

  As shown in FIG. 3, the 1: N optical branching unit 10 and the N: 1 optical multiplexing unit 30 in FIG. 1 include the 1: 2 optical branching unit 11, the wavelength selective switches 12 and 13, and the wavelength selective switches 32 and 33. The 2: 1 optical multiplexing unit 31 may be replaced. Here, consecutive optical subchannels belonging to a certain super channel are numbered sequentially from 1. As shown in FIGS. 4B and 4C, the wavelength selective switch 12 connected to one output of the 1: 2 optical branching unit 11 sets the center frequency of the passband to, for example, odd-numbered light. By matching with the subchannel, the odd-numbered optical subchannel is demultiplexed. As shown in FIGS. 4D and 4E, the wavelength selective switch 13 connected to the other output matches the even-numbered optical subchannel with the center frequency of the passband so that the even-numbered optical subchannel is matched. The optical subchannel is demultiplexed. Assuming that the typical loss of the wavelength selective switch is 6 dB, and considering the branch loss 3 dB that does not include the excess loss of the 1: 2 optical branching unit 11, the number of branches N is 8 or more (the wavelength of the multiplexer / demultiplexer loss) When the branching loss not including excess loss is 9 dB or more), it is possible to reduce the input / output loss of the optical subchannel identification / reproduction unit 20. Further, the total input optical power to each optical subchannel identification / reproduction unit 20 can be reduced, and the input power limitation to the optical subchannel selection receiving unit 21 can be relaxed.

  The wavelength selective switches 12, 13, 32, and 33 may be band variable wavelength selective switches. In this case, the optical subchannel selective receiver 21 changes the reception wavelength in accordance with the wavelength selected by the wavelength selective switches 12, 13, 32, and 33, and the optical subchannel transmitter 24 includes the wavelength selective switches 12, 13, 32, The transmission wavelength is changed in accordance with the 33 selection wavelengths.

  As shown in FIG. 6, the frame processing unit 23 is provided with a shared frame processing unit 25 in addition to the method of installing the optical subchannel identification / reproduction unit 20 individually, and the frame processing function is set to the transmission rate of the optical signal ( The optical signal 1 may be assigned to processing of each optical signal according to 300 Gb / s and the optical signal 2 may be 100 Gb / s). The allocated part constitutes virtual frame processing units 251 and 252.

  The optical subchannel identification / reproduction unit 20 reproduces an optical subchannel having a predetermined transmission rate for each optical subchannel identification / reproduction unit 20. Accordingly, as shown in FIG. 4, the wavelength selective switch 12 connected to one output of the 1: 2 optical branching unit 11 matches the center frequency of the passband with, for example, an odd-numbered subchannel. , Demultiplex odd-numbered subchannels. The wavelength selective switch 13 connected to the other output can demultiplex even-numbered subchannels by matching the center frequency of the passband with the even-numbered subchannels.

  Information necessary for reproducing the optical subchannel in the optical subchannel identification / reproduction unit 20 may be held in the optical subchannel identification / reproduction unit 20 in advance, or may be acquired from the outside. Necessary information includes, for example, a modulation format, a frame structure, an occupied frequency width, a frequency interval between adjacent ones, a polarization, a wavelength, a correction code, and a hierarchical structure. The acquisition source of such information is, for example, a management system.

  The input optical signal does not need to be limited to 300 Gb / s and 100 Gb / s as shown in FIG. 2, and the total transmission rate is 100 Gb / s or less in increments of 100 Gb / s, and optical signals that do not overlap in spectrum. If so, it is possible to identify and reproduce wavelength-division multiplexed optical signals having a plurality of transmission rates in any combination. For example, a combination of four optical signals (100 Gb / s, 100 Gb / s, 100 Gb / s, 100 Gb / s), a combination of three optical signals (100 Gb / s, 100 Gb / s, 200 Gb / s), (100 Gb / S, 300 Gb / s), a combination of two optical signals (400 Gb / s). The total transmission rate does not need to be the maximum 400 Gb / s. For example, a combination of three optical signals (100 Gb / s, 100 Gb / s, 100 Gb / s), (100 Gb / s, 200 Gb / s) A combination of two optical signals may be used. The above is an explanation when N is 4, and as described above, N can take an integer of 2 or more.

  According to the optical identification and reproduction apparatus of the present invention, one or a plurality of wavelength multiplexed optical signals to be input are each composed of one or a plurality of optical subchannels, and the total of those optical subchannels is N or less. Thus, it becomes possible to identify and reproduce an arbitrary number of wavelength multiplexed optical signals having an arbitrary transmission rate (the number of optical subchannels), which could not be realized by the prior art. As a result, it is possible to perform regenerative relaying in response to optical signals of various transmission rates with one type of optical identification / reproduction device. Furthermore, since one optical identification / reproduction device can identify and reproduce a plurality of optical signals, even if the transmission rate of the optical signal is lower than the maximum reproduction relay rate of the optical identification / reproduction device, the remaining processing of the optical identification / reproduction device Since the capability can be used for identifying and reproducing another optical signal, the capability of the optical identifying and reproducing apparatus can be utilized to the maximum, and the identification and reproducing cost per bit can be minimized.

  Further, since the wavelength of the optical subchannel can be converted into an arbitrary wavelength and output, blocking due to wavelength collision can be alleviated. In addition, the optical spectrum resources of the network can be used effectively because it can be output after being converted into a modulation format that minimizes the spectral width of the optical subchannel according to the transmission distance after regenerative relaying. Can do.

[Second Embodiment]
Next, FIG. 7 shows a configuration of an optical switching device according to the second embodiment of the present invention. FIG. 7 is a diagram for explaining an implementation method when the optical path switching device is ROADM. For simplicity, only one direction is shown. Moreover, the spectrum in each point of FIG. 7 is shown in FIG. The optical switching device of the present invention shown in FIG. 7 includes an optical splitter 51, a branching variable bandwidth wavelength selection switch 52, an insertion variable bandwidth wavelength selection switch 54, an output variable bandwidth wavelength selection switch 55, and an optical identification and reproduction device of the present invention. The device 53 is configured.

  The variable wavelength selective switch 55 is an optical switch having a plurality of input ports and one output port, and outputs an arbitrary optical signal among a plurality of wavelength multiplexed optical signals input from a certain input port to the output port. It is possible to operate in the opposite direction. Furthermore, the optical frequency range to be switched can be changed according to the occupied spectrum width of the optical signal to be switched. Hereinafter, the optical frequency range to be switched is referred to as a frequency slot.

The frequency slot can be defined by the center frequency and the width of the frequency slot. Such a band variable wavelength selective switch can be realized by combining an optical spatial modulation element and a diffraction grating as shown in Non-Patent Document 6, for example. The input wavelength-multiplexed optical signal L _A, consider a case composed of a plurality of super-channel optical signal transmission rates are different as shown in FIG. 8 (a).

Wavelength-multiplexed optical signal L _A that is input is 2 minutes by an optical splitter 51, one output for the band variable wavelength selection switch 55, the other branch for the band variable wavelength selection switch 52 are input. The branching variable bandwidth wavelength selection switch 52 outputs only the optical signals 1 to 3 that require identification and reproduction to the port to which the optical identification and reproduction devices 53-1 and 53-2 are connected. In this example, the optical signals 1 and 2 are input to the optical identification / reproduction device 53-1, and the optical signal 3 is input to the optical identification / reproduction device 53-2. The optical identification / reproduction devices 53-1 and 53-2 perform identification / reproduction processing of a plurality of wavelength-multiplexed optical signals by the mechanism described in the first embodiment of the present invention and Lead. The insertion band variable wavelength selection switch 54 multiplexes the discriminated and reproduced optical signal and the optical signal to be inserted, and inputs the multiplexed optical signal to the output band variable wavelength selection switch 55. Band tunable wavelength selective switch output 55 of the input wavelength-multiplexed optical signal L _A, and the optical signal L _A to be as it passes through the optical path switching device, the inserted optical signal L _F of the reproducing optical signal Are combined and output.

  Next, an example of an implementation method when the optical path switching device is WXC will be described with reference to FIG. In the case of WXC, since there are a plurality of routes connected to the optical network, the output band variable wavelength selective switch 55 is arranged according to the number of routes. When a wavelength collision occurs in the output band variable wavelength selective switch 55 connected to the branching band variable wavelength selective switch 52, a plurality of output band variable wavelength selective switches 55 can be arranged to avoid this. .

  Further, as shown in FIG. 10, n-input m-output band variable wavelength selective switches may be used for the branching variable band wavelength selective switch 52 and the inserting band variable wavelength selective switch 54, respectively. In either case, the input / output ports of the optical output regenerators 53-1 and 53-2 need to be arranged so that the spectra of a plurality of super channels that pass through do not overlap.

  The configuration of the band optical path switching unit is not limited to the configuration illustrated in FIG. 9. For example, even in the configuration in which the band variable function is added to the switch element in the node device configuration described in Non-Patent Document 7, It can be used as the band variable optical switching function of the present invention.

  The wavelength of the optical signal to be identified and reproduced by the optical identification / reproduction devices 53, 53-1, and 53-2 does not have to be the same as the input optical signal, and is converted to an arbitrary wavelength and output as shown in FIG. Can do. Thereby, the spectrum utilization efficiency of the whole optical network can be improved.

  Further, the modulation format of the optical signal to be identified and reproduced by the optical identification / reproduction devices 53, 53-1, and 53-2 does not have to be the same as the input optical signal, and is converted into an arbitrary modulation format as shown in FIG. Can be output. For example, when the transfer distance after the identification reproduction is short, a modulation method such as 16-QAM or 64-QAM that employs a modulation method with high multilevel and high frequency utilization efficiency, and a client signal with a long transfer distance after identification reproduction. For the conversion to an optical signal corresponding to the above, a modulation method having a low multi-value level and an excellent SNR tolerance such as BPSK (Binary Phase Shift Keying) and QPSK (Quadrature Phase Shift keying) can be adopted. In this way, the spectrum utilization efficiency of the entire optical network can be increased by assigning the minimum required optical spectrum according to the transfer distance.

  Further, for a plurality of optical signals having the same path after identification and reproduction, as shown in FIG. 13, the wavelength can be converted and output so that the optical subchannels are adjacent to each other with a minimum interval. In this way, it is only necessary to optically switch in one frequency slot with a narrow occupied spectrum width in the subsequent paths, and the spectrum utilization efficiency of the entire optical network can be improved.

  Further, when a group of frequency slots cannot be secured in the path after the identification reproduction, one optical signal can be divided into a plurality of frequency slots and transferred as shown in FIG. In this case, the transfer route need not be the same, and may be sent by another route.

  The present invention can be applied to the information communication industry.

10: 1 to N optical branching unit 11: 1 to 2 optical branching unit 12, 13: wavelength selective switch 20: optical subchannel identification / reproducing unit 21: optical subchannel selection receiving unit 22: threshold processing unit 23: frame processing unit 24 : Optical subchannel transmission unit 25: Shared frame processing unit 251 and 252: Virtual frame processing unit 30: Optical multiplexing unit 31: 2 to 1 optical multiplexing unit 32 and 33: Band variable wavelength selective switch 51: Optical splitter 52: Branch Band variable wavelength selective switches 53, 53-1, 53-2: optical discriminating / reproducing device 54: insertion band variable wavelength selective switch 55: output band variable wavelength selective switch 151: optical splitter 152: wavelength separation unit 153: light Identification / reproduction device 1531: optical receiver 1532: frame processor 1533: optical transmitter 154: wavelength multiplexer 155: wavelength selective switch

Claims (5)

An optical identification / reproduction device that identifies and reproduces one or a plurality of wavelength-multiplexed optical signals deteriorated by transmission,
Each optical signal included in the wavelength multiplexed optical signal consists of one or a plurality of optical subchannels,
Means for branching the optical signal into N parts;
N optical subchannel identifying and reproducing means for selectively receiving one optical subchannel in the branched optical signal and outputting the optical subchannel as an identified and reproduced optical subchannel;
Means for combining and outputting the optical subchannels identified and reproduced by the optical subchannel identification and reproduction means;
An optical identification reproducing apparatus comprising:   2. The optical identification / reproduction apparatus according to claim 1, wherein the optical sub-channel identification / reproduction means includes a function of correcting a code error included in the identified optical sub-channel.   3. The optical identification / reproduction apparatus according to claim 1, wherein the optical sub-channel identification / reproduction means includes a function of converting the wavelength of the selectively received optical sub-channel into another wavelength and outputting the wavelength.   4. The optical sub-channel identification / reproducing unit includes a function of converting a modulation format of a selectively received optical sub-channel into another modulation format and outputting it. Optical identification reproduction device. In an optical path switching device having a function of multiplexing, demultiplexing, inserting, branching and route allocation of wavelength multiplexed optical signals,
The input port of the optical identification reproducing device according to any one of claims 1 to 4 is connected to at least one of the branch ports for branching the wavelength multiplexed optical signal,
The output port of the optical identification reproducing device according to any one of claims 1 to 4 is connected to at least one of the insertion ports into which the wavelength multiplexed optical signal is inserted.
Optical path switching device.

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