JP6200406B2 - Optical transmission apparatus and optical transmission method - Google Patents

Description

  The present invention relates to an optical transmission device and an optical transmission method.

  An OTN (Optical Transport Network) which is a large-capacity wide-area optical transport network accommodates and transfers various client signals such as SDH (Synchronous Digital Hierarchy) and Ethernet (registered trademark). In recent years, the increase in traffic of client signals has been remarkable, and along with this, standardization has been advanced so that OTN can cope with higher speed (for example, see Non-Patent Document 1). Currently, OTUCn (Cn represents 100G × n), which is an OTN technology exceeding 100 G (B100G, G is gigabit per second), is being studied (for example, see Non-Patent Document 2). In OTUCn, the transmission capacity of one optical channel is wider than that of a conventional OTU. However, due to the relationship between the operating speeds of electronic circuits used in optical signal transceivers, it is difficult to increase the capacity by expanding single carrier transmission in the band of one optical channel as in the past. Therefore, in OTUCn, it has been studied to realize a large capacity by multicarrier transmission using a plurality of optical subcarriers in a band of one optical channel.

  FIG. 11 is a block diagram illustrating a configuration example of an optical transmission apparatus 90 using an OTU / OTUCn frame structure. As shown in the figure, the optical transmission apparatus 90 includes a plurality of client side interface units 310 (310-1 to 310-k), a backplane unit 320, and two line side interface units 930 (930-1 and 930-2). ). The plurality of client side interface units 310 are provided according to the number of client signals to be accommodated.

  Each of the client side interface units 310 generates an ODTU frame as a lower order optical channel data unit (LO-ODU) including a client signal received from an external device. The client side interface unit 310 outputs the generated ODTU frame signal (hereinafter referred to as ODTU signal) to the associated line side interface unit 930 via the backplane unit 320. The client-side interface unit 310 maps the received client signal to the payload in the ODTU signal and adds an ODTU OH (overhead) to generate an ODTU signal.

  Further, each of the client side interface units 310 inputs an ODTU signal from the line side interface unit 930 via the backplane unit 320. The client side interface unit 310 extracts a client signal from the ODTU signal input from the backplane unit 320. The client side interface unit 310 transmits the extracted client signal to an external device.

  The backplane unit 320 interconnects the associated client-side interface unit 310 and the line-side interface unit 930, and exchanges ODTU signals.

  Each of the line side interface units 930 generates an ODUCn frame from an ODTU signal input via the backplane unit 320. The line side interface unit 930 transmits an optical signal obtained by performing electro-optical conversion on the electric signal of the ODCUn frame. Further, the line side interface unit 930 restores the ODTU signal from the ODUCn frame obtained by performing the photoelectric conversion on the received optical signal. The line-side interface unit 930 outputs the restored ODTU signal to the associated client-side interface unit 310 via the backplane unit 320.

  Each of the line side interface units 930 includes a backplane interface unit (backplane I / F unit) 331, a mapping unit 933, a transmission side overhead / FEC processing unit (transmission side OH-FEC processing unit) 935, a transmission unit 336, and a reception unit. 337, a reception-side overhead / FEC processing unit (reception-side OH-FEC processing unit) 938, and a demapping unit 940.

  The backplane interface unit 331 outputs the ODTU signal input from the client side interface unit 310 via the backplane unit 320 to the mapping unit 933. Further, the backplane interface unit 331 outputs the ODTU signal input from the demapping unit 940 to the client side interface unit 310 via the backplane unit 320.

  The mapping unit 933 maps the ODTU signal to the payload area of the ODUCn frame and outputs it to the transmission-side overhead / FEC processing unit 935. The transmission-side overhead / FEC processing unit 935 adds overhead and FEC (Forward Error Correction) to the ODUCn frame input from the mapping unit 933 and outputs the result to the transmission unit 336. The transmission unit 336 transmits an optical signal obtained by optically modulating the ODUCn frame input from the transmission-side overhead / FEC processing unit 935.

  The receiving unit 337 outputs an ODUCn electrical signal obtained by performing optical-electrical conversion on the received optical signal to the reception-side overhead / FEC processing unit 938. The reception-side overhead / FEC processing unit 938 performs error correction decoding using the FEC added to the ODUCn frame input from the reception unit 337 and then extracts the payload area of the ODUCn frame. The demapping unit 940 receives the payload area data extracted by the receiving-side overhead / FEC processing unit 938, and extracts the ODTU signal by performing demapping on the data. The demapping unit 940 outputs the extracted ODTU signal to the corresponding client side interface unit 310 via the backplane interface unit 331 and the backplane unit 320.

  In the optical transmission apparatus 90 configured as described above, since processing such as mapping of client signals to OTUCn frames, overhead processing, and frame synchronization is performed for each line-side interface unit 930, a plurality of line-side interface units 930 are provided. It is difficult to map a client signal to signals of different subcarriers across For example, since there is dynamic processing such as staff processing and rate processing in GMP (Generic Mapping Procedure), it is difficult to perform GMP mapping for one ODTU signal by a plurality of line side interface units 930. It has become.

As described above, when transmission using the OTU / OTUCn frame structure is performed by the optical transmission apparatus 90 having the above-described configuration, when the bandwidth per line-side interface unit 930 is smaller than the OTUCn frame, the following restrictions are imposed. There is.
(1) One client signal (OTDU signal) cannot exceed the bandwidth per line-side interface unit 930.
(2) When the line side interface unit 930 is divided and used in units of wavelengths, one ODTU signal cannot exceed the assigned divided band.
(3) Regarding transmission, it is necessary to arrange and rearrange the tributary slots so that one client signal is accommodated in one line-side interface unit 930.
(4) Regarding reception, when one client signal is accommodated in a plurality of line-side interface units 930, it is necessary to perform demapping in the client-side interface unit 310.

  FIG. 12 is a diagram illustrating an example of mapping of a client signal (ODTU signal) to an OTUCn frame in the optical transmission apparatus 90. In the example shown in the figure, a case where four client signals Sig9-a to Sig9-d are mapped to two OTUC2 frames is shown. Further, it is assumed that two wavelengths of different line side interface units 930 are used due to the limitation of the output wavelength.

  Each client signal is input to the line-side interface unit 930 via the backplane unit 320. In the example shown in the figure, the client signal Sig9-a is rearranged with respect to the tributary slot so as to be accommodated in the OTUC2 frame of the output wavelength λ2 of the line side interface unit 930-2. When rearrangement is performed, it is necessary to notify the opposite device (reception-side optical transmission device 90) of the rearrangement result via a control plane or the like. Further, since the client signal Sig9-c exceeds the allocated one wavelength band, it cannot be accommodated in the OTUC2 frame. In this case, it is necessary to reduce the bandwidth of the client signal Sig9-c.

"Interfaces for the optical transport network", ITU-T G.709 / Y.1331, February 2012 Takuya Ohara, “OTN Interface Technology and Standardization Trends”, 2014 IEICE General Conference, Proceedings of Communication Lecture 2, BI-5-1, SS-47-SS-48, March 2014

  As described above, if the client signal cannot be mapped across a plurality of line side interface units, a restriction in transmission occurs.

  In view of the above circumstances, an object of the present invention is to provide an optical transmission apparatus and an optical transmission method that enable mapping of a client signal across a plurality of line side interface units.

  One aspect of the present invention includes a plurality of client-side interface units that input and output an ODTU signal containing a client signal, a plurality of line-side interface units that input and output an OTUCn frame contained in an optical signal, and a plurality of the clients An optical transmission apparatus including a backplane unit that exchanges an ODTU signal between the side interface unit and the plurality of line side interface units, wherein the line side interface unit is connected to the client via the backplane unit. ODTU that acquires information on the ODTU signal from the side interface unit, virtually maps the ODTU signal to an OTUCn frame across multiple wavelengths based on the information on the ODTU signal, and stores the client signal based on the mapping result A virtual map calculation unit for generating transfer instruction information for requesting the client-side interface unit to output a signal, and an ODTU signal output from the client-side interface unit according to the transfer instruction information based on the mapping result An optical transmission apparatus comprising: a mapping unit that maps to an OTUCn frame; and a transmission unit that optically modulates and outputs an OTUCn frame to which an ODTU signal is mapped by the mapping unit.

  According to another aspect of the present invention, in the optical transmission device, the line-side interface unit outputs an OTUCn frame obtained by optical demodulation of an optical signal output from another optical transmission device. And a demapping unit that outputs an ODTU signal extracted by demapping the OTUCn frame output from the optical receiving unit to the client side interface unit to the backplane unit.

  Further, according to one aspect of the present invention, a plurality of client-side interface units that input and output an ODTU signal containing a client signal, a plurality of line-side interface units that input and output an OTUCn frame contained in an optical signal, An optical transmission device comprising: a backplane unit that passes an ODTU signal between the client side interface unit and the plurality of line side interface units; and a line side interface connection unit that connects the plurality of line side interface units The line-side interface unit acquires an ODTU signal and information related to the ODTU signal from the client-side interface unit via the backplane unit, and accommodates the ODTU signal in an OTUCn frame spanning a plurality of wavelengths. Based on the virtual map calculation unit for determining the storage position and the staff position, and the storage position and the staff position determined by the virtual map calculation unit, the ODTU signal acquired from the client side interface unit via the backplane unit A mapping unit that maps to an OTUCn frame; and a transmission unit that optically modulates and outputs an OTUCn frame to which the ODTU signal is mapped by the mapping unit, wherein the virtual map calculation unit is specific to the transmission of the ODTU signal OTUCn frame that accommodates the ODTU signal addressed to the line-side interface unit that includes a transmission unit that transmits an optical signal that satisfies the constraint is provided when the optical signal having the wavelength of the optical signal is used. Control to transfer to An optical transmission apparatus characterized.

  Further, according to one aspect of the present invention, a plurality of client-side interface units that input and output an ODTU signal containing a client signal, a plurality of line-side interface units that input and output an OTUCn frame contained in an optical signal, An optical transmission method in an optical transmission device comprising a backplane unit that exchanges an ODTU signal between the client side interface unit and the plurality of line side interface units, wherein the line side interface unit includes the backplane Information about the ODTU signal is acquired from the client-side interface unit via the unit, the ODTU signal is virtually mapped to an OTUCn frame spanning a plurality of wavelengths based on the information about the ODTU signal, and the client is based on the mapping result. A first step of generating transfer instruction information requesting the client-side interface unit to output an ODTU signal containing the signal; and the client-side interface unit sends the ODTU signal to the line according to the transfer instruction information A second step of outputting to the side interface unit; a third step of mapping the ODTU signal output from the client side interface unit to an OTUCn frame based on the mapping result; And a fourth step in which the side interface unit optically modulates and outputs the OTUCn frame to which the ODTU signal is mapped in the third step.

  Further, according to one aspect of the present invention, a plurality of client-side interface units that input and output an ODTU signal containing a client signal, a plurality of line-side interface units that input and output an OTUCn frame contained in an optical signal, An optical transmission device comprising: a backplane unit that passes an ODTU signal between the client side interface unit and the plurality of line side interface units; and a line side interface connection unit that connects the plurality of line side interface units The line-side interface unit obtains an ODTU signal and information related to the ODTU signal from the client-side interface unit via the backplane unit, and the OTTUn signal spans a plurality of wavelengths. A first step of determining an accommodation position and a staff position when accommodating in the room, and the line-side interface unit determines the backplane part based on the accommodation position and the staff position determined in the first step. A second step of mapping the ODTU signal acquired from the client-side interface unit to the OTUCn frame, and the line-side interface unit optically modulates the OTUCn frame to which the ODTU signal is mapped in the second step. A third step of outputting, and a transmitter that transmits an optical signal that satisfies the restriction when the line-side interface is provided with a restriction to use an optical signal of a specific wavelength for transmission of an ODTU signal. The ODT addressed to the line side interface unit An optical transmission method characterized in that it comprises a fourth step of performing control to transfer the OTUCn frame for housing a signal to the line side interface connecting portion.

  According to the present invention, client signals can be mapped across a plurality of line side interface units.

1 is a functional block diagram of a framer 100 to which an embodiment of the present invention can be applied. It is a figure which shows the frame structure of OTUCn. OTLCn. It is a figure which shows the frame structure of n. It is a figure which shows the optical channel used for transmission of an optical signal. It is a block diagram which shows the structural example of the optical transmission apparatus 30 in 1st Embodiment which concerns on this invention. FIG. 6 is a diagram illustrating a flow of information in mapping and OTUCn frame arrangement change in the optical transmission device 30. It is a block diagram which shows the structural example of the optical transmission apparatus 40 in 2nd Embodiment. FIG. 11 is a diagram illustrating a flow of information in a virtual mapping and transfer instruction information generation process in the optical transmission device 40. It is a figure which shows an example of the address table obtained from the result of virtual mapping. FIG. 9 is a diagram illustrating an outline of an OTUCn frame generated by the line side interface unit 430 based on the result of the virtual mapping and transfer instruction information generation process illustrated in FIG. 8. It is a block diagram which shows the structural example of the optical transmission apparatus 90 using the frame structure of OTU / OTUCn. 6 is a diagram illustrating an example of mapping of a client signal (ODTU signal) to an OTUCn frame in the optical transmission device 90. FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a functional block diagram of an OTN framer 100 to which an embodiment of the present invention can be applied. The OTN framer 100 shown in the figure is an OTN (Optical Transport Network) standard OTUCn (Cn represents 100G × n, where n is 2 or more) for transmission of more than 100G (B100G, G is gigabit per second). (Integer). In the figure, an example in the case of n = 4, that is, a case where the OTN framer 100 performs communication by OTUC4 is shown.

  In the OTN transport technology, client signals of various communication methods are accommodated and transferred by optical transmission. In OTN, a fixed frame structure is used and ODU0 (ODU: Optical Channel Data Unit), which is the smallest unit capable of accommodating GbE (Gigabit Ethernet (registered trademark)), is also referred to as a 1.25G TS (Tributary slot, time slot). .) Handle client signals in units (ie by multiples thereof). The OTN provides the same path management, OAM (Operations, Administration, Maintenance) function, and protection function as SDH (synchronous digital hierarchy).

  The OTN framer 100 separates a signal of one optical channel of nx100G in which a plurality of client signals are multiplexed, and generates n 100G parallel signals. These n parallel signals are multi-carrier transmitted by a plurality of optical subcarriers, but physically one parallel signal may be transmitted by one optical subcarrier, and a plurality of parallel signals are one It may be transmitted by an optical subcarrier. Multi-carrier transmission is a communication method for increasing the capacity of one channel by transmitting a signal of one channel in parallel using a plurality of optical subcarriers. In multicarrier transmission, subcarriers are densely multiplexed for each ground (connection destination) and electrically separated. When one parallel signal is transmitted by one optical subcarrier, the bandwidth of the optical subcarrier is 100 G. When two parallel signals are transmitted by one optical subcarrier, the bandwidth of the optical subcarrier is 200 G. It is. For optical transmission, 4SC-DP-QPSK (4 subcarrier-Dual Polarization-Quadrature Phase Shift Keying), 2SC-DP-16QAM (2 subcarrier-Dual Polarization-Quadrature Amplitude Modulation), or the like is used.

  As shown in FIG. 1, the OTN framer 100 includes a transmission processing unit 110 and a reception processing unit 150. The transmission processing unit 110 includes a client signal receiving unit 120, a multiprocessing unit 130, and a line side transmission processing unit 140.

  The client signal receiving unit 120 includes a receiving unit 121, a mapping unit 122, and an OH processing unit 123. The receiving unit 121 receives a client signal. The mapping unit 122 maps one client signal received by the receiving unit 121 to a payload of a LO-ODU (Lower Order Optical Channel Data Unit) frame. The OH processing unit 123 adds OH (overhead) to the LO-ODU frame in which the mapping unit 122 sets the client signal. The OH processing unit 123 outputs the electrical path signal of the LO-ODU frame to the ODU-switch (hereinafter referred to as “ODU-SW”) 210. The ODU-SW 210 is also connected to other OTN framers 100, and performs path exchange of electrical path signals.

  The multiprocessing unit 130 includes a multiplexing unit 131 and a framing unit 132. The multiplexing unit 131 sets the electrical path signal received from the ODU-SW 210 in the LO-ODU frame. The multiplexing processing unit 130 once maps the LO-ODU frame to an ODTU (Optical Channel Data Tributary Unit) frame, and then time-multiplexes the plurality of ODTU frames to generate an ODUCn frame that is a HO-ODU (Higher Order ODU). . The framing unit 132 adds OH and FEC (forward error correction) to the ODUCn frame generated by the multiprocessing unit 130 to generate an OTUCn frame. The framing unit 132 outputs the signal of the OTUCn frame to the line side transmission processing unit 140.

The line side transmission processing unit 140 includes an interleaving unit 141, OH processing units 142-1 to 142-n, and multilane transmission units 143-1 to 143-n.
The interleaving unit 141 receives an OTUCn frame signal from the multiprocessing unit 130, byte-interleaves the received n × 100G OTUCn frame signal, and generates n OTLCn. An n-frame signal is generated. OTLCn. The n frame is a frame of a 100 G parallel signal. i-th OTLCn. n frames, OTLCn. n # i frame (where i is an integer from 1 to n). The interleaving unit 141 includes the generated n OTLCn. Each n # i frame is output to the OH processing unit 142-i.

The OH processing units 142-1 to 142-n receive the OTLCn. Set OH to n frames. The OH processing unit 142-i is an OTLCn. The n # i frame is output to the multilane transmission unit 143-i.
The multilane transmission units 143-1 to 143-n receive the OTLCn. The n-frame parallel signal is output to the transmitter 220. For example, the multi-lane transmission unit 143-i uses four 28G electric wires in parallel to perform OTLCn. The parallel signal of the n # i frame is output to the transmitter 220. Each transmitter 220 uses an optical subcarrier having a different wavelength. The transmitter 220 converts the received parallel signal from an electrical signal to an optical signal and performs multicarrier transmission. A plurality of multilane transmission units 143-i may be connected to one transmitter 220. When j (j is 2 or more and n or less) multi-lane transmission units 143-i are connected to one transmitter 220, the transmitter 220 transmits j parallel signals using j × 100G optical subcarriers. To transmit.

  The reception processing unit 150 includes a line side reception processing unit 160, a separation processing unit 170, and a client signal transmission unit 180.

The line side reception processing unit 160 includes multilane reception units 161-1 to 161-n, OH processing units 162-1 to 162-n, and a deinterleaving unit 163.
The multilane receiving units 161-1 to 161-n receive optical signals received by the receiver 230 through multicarrier transmission as electrical signals. The receiver 230 receives optical signals using optical subcarriers having different wavelengths, converts the received optical signals into electrical signals, and outputs the electrical signals to the multilane receivers 161-1 to 161-n. The multilane receiving unit 161-i outputs, for example, an electrical signal received in parallel from the receiver 230 using four 28G electrical wirings to the OH processing unit 162-i.

The OH processing units 162-1 to 162-n receive OTLCn. The head of the frame is detected based on FAS (frame alignment signal) and MFAS (multi frame alignment signal) set in OH of n frames. The OH processing unit 162-i detects the head position, compensates for the delay time difference, and detects the OTLCn. The n # i frame is extracted and output to the deinterleave unit 163.
The deinterleaving unit 163 receives the OTLCn.1 received from the OH processing units 162-1 to 162-n. n # 1 frame to OTLC n. n # n frames are deinterleaved to generate one OTUCn frame.

  The separation processing unit 170 includes a deframing unit 171 and a demultiplexing unit 172. The deframing unit 171 performs FEC decoding on the signal of the OTUCn frame generated by the deinterleaving unit 163, extracts an ODUCn frame in which the LO-ODU frame is time-multiplexed from the decoded OTUCn frame, and outputs the ODUCn frame to the demultiplexing unit 172. . The demultiplexing unit 172 extracts the LO-ODU frame in which each client signal is set from the ODUCn frame signal extracted by the deframing unit 171, and outputs the LO-ODU frame electrical path signal to the ODU-SW 210.

  The client signal transmission unit 180 includes an OH processing unit 181, a demapping unit 182, and a transmission unit 183. The OH processing unit 181 receives the electrical path signal from the ODU-SW 210 and decodes the LO-ODU frame from the received electrical path signal. The OH processing unit 181 performs processing related to OH on the LO-ODU frame and outputs the OH processing unit 181 to the demapping unit 182. The demapping unit 182 receives the electrical path signal of the LO-ODU frame from the OH processing unit 181, extracts a client signal from the received electrical path signal, and outputs the client signal to the transmission unit 183. The transmission unit 183 transmits the client signal extracted by the demapping unit 182.

  Note that the client signal receiving unit 120 and the multiplex processing unit 130 may directly input / output the electrical path signal of the LO-ODU frame without going through the ODU-SW 210. Further, the separation processing unit 170 and the client signal transmission unit 180 may directly input / output the electrical path signal of the LO-ODU frame without going through the ODU-SW 210.

  FIG. 2 is a diagram illustrating a frame structure of OTUCn. OTUCn is generated by adding FACnOH, OTUCnOH, OPUCnOH, and OTUCnFEC to ODUCn. The frame structure of OTUCn is represented by 4 rows and 4080 × n columns.

  A client signal is mapped to the OPUCn payload (Payload) in the ((7 + 7 + 2) × n + 1) to 3824 × n columns of OTUCn. OH is set in the 1st to (7 + 7 + 2) × n columns of the OTUCn frame. FACnOH is set in the first row of 1-7 × n columns in OH. The FACnOH includes information necessary for frame synchronization. OTUCnOH is set in the (7 × n + 1) to 14 × n columns in OH. The OTUCnOH contains section monitoring information for the optical channel. ODUCnOH is set in the 1st to 14th × nth columns of the 2nd to 4th rows in OH. ODUCnOH is set to OPUCnOH in the (14 × n + 1) to 16 × n columns that store path management operation information of optical channels. OPUCnOH contains information necessary for mapping / demapping of client signals. OPUCnFEC is set in the 3824 × n + 1 to 4080 × n columns. OPUCnFEC contains a parity check byte for FEC.

  FIG. 3 shows OTLCn. It is a figure which shows the frame structure of n. OTLCn. n is represented by 4 rows and 4080 columns. OTLCn. n # 1-OTLC n. n # n is obtained by dividing the OTUCn frame by byte interleaving. The OTUCn payload of OTUCn is OTLCn. n # i of OPUCn. Maps to n # i payload.

  OTLCn. OH is set in the 1st to 16th columns of n # i. OTLCn. The OH of n # i is set based on OTUCnOH or the like. In the 1st to 7th columns of the first row, FALCn. n # iOH is set. FALCn. n # iOH includes information necessary for frame synchronization. In the 8th to 14th columns, OTLCn. n # iOH is set. OTLCn. n # iOH accommodates section monitoring information of the optical channel. In the 1st to 14th nth columns of the 2nd to 4th rows, ODLCn. n # iOH is set. ODLCn. The n # iOH accommodates optical channel path management operation information. In columns 15-16, OPLCn. n # iOH is set. OPLCn. n # iOH stores information necessary for mapping / demapping of client signals. OTUC # iFEC is set in the 3825th to 4080th columns. OUTC # iFEC contains a parity check byte for FEC.

  FIG. 4 is a diagram illustrating an optical channel used for transmission of an optical signal. 4A is a diagram showing an optical channel when a 400G optical signal is serially transmitted by one optical carrier, and FIG. 4B is a parallel transmission of a 400G optical signal by four optical subcarriers. It is a figure which shows the optical channel in the case of (multicarrier transmission). In an electronic circuit, it is difficult to continue to expand the capacity of a band that can be serially transmitted by one optical carrier beyond 100 G, as shown in FIG. Therefore, in OTUCn, broadband transmission is realized without being restricted by the operation speed of the electronic circuit by performing parallel transmission of a band exceeding 100 G using a plurality of optical subcarriers. For this parallel transmission, polarization multiplexing, multilevel modulation, or the like is used. The optical subcarrier band varies depending on the modulation method.

  FIG. 4B shows an example in which one 400 G optical channel is transmitted in parallel by 100 G four optical subcarriers. FIG. 4C shows one 400 G optical channel through 200 G two optical subcarriers. This is an example when parallel transmission is performed. Further, by changing n, as shown in FIG. 4D, the transmission band can be increased in units of 100G.

(First embodiment)
FIG. 5 is a block diagram illustrating a configuration example of the optical transmission device 30 according to the first embodiment of the present invention. As shown in the figure, the optical transmission device 30 includes a plurality of client side interface units 310 (310-1 to 310-k), a backplane unit 320, and two line side interface units 330 (330-1 and 330-2). ), A control signal transmission unit 341, and a control signal reception unit 342. The plurality of client side interface units 310 are provided according to the number of client signals to be accommodated. In the optical transmission device 30, the same components as those included in the optical transmission device 90 illustrated in FIG. In the configuration example illustrated in FIG. 5, the optical transmission device 30 includes two line-side interface units 330, but may include three or more line-side interface units 330.

  In the optical transmission device 30, the client side interface unit 310 corresponds to the client signal reception unit 120 and the client signal transmission unit 180 in FIG. The backplane unit 320 corresponds to the ODU-SW 210 in FIG. Each of the line side interface units 330-1 and 330-2 corresponds to the multiplex processing unit 130, the line side transmission processing unit 140, the transmitter 220, the receiver 230, the line side reception processing unit 160, and the separation processing unit 170 in FIG. To do.

  The line side interface unit 330 includes a backplane interface unit 331, a virtual map calculation unit 332, a mapping unit 333, a line side interface connection unit 334, a transmission side overhead / FEC processing unit 335, a transmission unit 336, a reception unit 337, and a reception unit. Side overhead / FEC processing unit 338, line side interface connection unit 339, and demapping unit 340. Note that the line-side interface connection unit 334 connects the two line-side interface units 330 and exists as one component in the optical transmission device 30. Similarly, the line side interface connection unit 339 connects the two line side interface units 330 and exists as one component in the optical transmission device 30.

  The virtual map calculation unit 332 acquires the ODTU signal, OTDU signal identifier, data amount, payload type, and client side time information output from the client side interface unit 310 via the backplane unit 320 and the backplane interface unit 331. To do. The virtual map calculation unit 332 calculates the ratio between the bit rate in the OTDU signal input from the client side interface unit 310 and the bit rate in the line side interface unit 330 in real time. Note that the virtual map calculation unit 332 calculates the average value of the bit rate on the client side using the client side time information.

  The virtual map calculation unit 332 determines whether the ITU-T G.I. The number of client data entities Cm and ΣCnD for the OTUCn frame determined in 709 is calculated. The virtual map calculation unit 332 calculates the calculated client data entity numbers Cm and ΣCnD and ITU-T G.D. Using the GMP mapping algorithm defined in 709, the accommodation position and the stuff position in the OTUCn frame that spans a plurality of wavelengths of the ODTU signal are determined, and the ODTU signal is virtually mapped.

  The virtual map calculation unit 332 determines whether or not part or all of the virtually mapped OTUCn frame needs to be transmitted by the other line side interface unit 330 due to restrictions such as the output wavelength. The restriction on the output wavelength is, for example, when a specific wavelength needs to be used for transmission of the ODTU signal (client signal). When the output wavelength of the optical signal output from the transmission unit 336 of the line-side interface unit 330 in which the virtual map calculation unit 332 is provided does not satisfy the constraint, the virtual map calculation unit 332 stores an OTUCn frame containing the ODTU signal having the constraint. Is output to the other line side interface unit 330.

  The virtual map calculation unit 332 outputs mapping information indicating mapping of the calculated OTUCn frame to the mapping unit 333. When the OTUCn frame is output to the other line side interface unit 330, the virtual map calculation unit 332 outputs switching information indicating the output target OTUCn frame and the output side line side interface unit 330 of the OTUCn frame as a control signal. The data is output to the transmission unit 341.

  The control signal transmission unit 341 controls the line side interface connection unit 334 based on the switching information input from the virtual map calculation unit 332 of each of the line side interface units 330-1 and 330-2. In addition, the control signal transmission unit 341 sends a change signal including the presence / absence of the change in the arrangement of the OTUCn frame between the line side interface units 330 and the change when the arrangement change is performed to the opposite device (the optical transmission device on the reception side). 30).

  The mapping unit 333 acquires the ODTU signal output from the client side interface unit 310 via the backplane unit 320 and the backplane interface unit 331. The mapping unit 333 performs mapping for accommodating the ODTU signal in the OTUCn frame based on the accommodation position and the staff position indicated by the mapping information output from the virtual map calculation unit 332. The mapping unit 333 outputs the OTUCn frame containing the ODTU signal to the line side interface connection unit 334.

  Under the control of the control signal transmission unit 341, the line side interface connection unit 334 converts the OTUCn frames output from the mapping units 333 of the line side interface units 330-1 and 330-2 into the line side interface unit 330-1. And 330-2 to the transmission-side overhead / FEC processing unit 335. When there is a change in the arrangement of the OTUCn frame between the line side interface units 330, the line side interface connection unit 334 transmits the transmission side of the other line side interface unit 330 in which the OTUCn frame specified as the target of the arrangement change is specified. It outputs to the overhead / FEC processing unit 335, and outputs the OTUCn frame not designated as the target of the arrangement change to the transmission side overhead / FEC processing unit 335 of the same line side interface unit 330 as the output source. When there is no change in the arrangement of the OTUCn frame, the line-side interface connection unit 334 outputs the OTUCn frame to the transmission-side overhead / FEC processing unit 335 of the same line-side interface unit 330 as each output source.

  The transmission-side overhead / FEC processing unit 335 adds overhead and FEC to the OTUCn frame output from the line-side interface connection unit 334 and outputs the result to the transmission unit 336. The transmission unit 336 transmits an optical signal obtained by optical modulation with the electrical signal of the OTUCn frame output from the transmission-side overhead / FEC processing unit 335.

  The reception unit 337 outputs the electrical signal of the OTUCn frame obtained by optical demodulation of the optical signal received from the opposite device (the transmission-side optical transmission device 30) to the reception-side overhead / FEC processing unit 338. The receiving-side overhead / FEC processing unit 338 extracts the payload area of the OTUCn frame after performing error correction decoding using the FEC added to the OTUCn frame output from the receiving unit 337. The reception-side overhead / FEC processing unit 338 outputs the extracted payload area of the OTUCn frame to the line-side interface connection unit 339.

  The control signal receiving unit 342 receives a change signal from the opposite device (the transmission-side optical transmission device 30), and controls the line-side interface connection unit 339 based on the received change signal. Under the control of the control signal receiving unit 342, the line side interface connecting unit 339 determines the payload area of the OTUCn frame output from the receiving side overhead / FEC processing unit 338 of each of the line side interface units 330-1 and 330-2. , Output to the demapping unit 340 of each of the line side interface units 330-1 and 330-2.

  When there is a change in the arrangement of the OTUCn frame between the line side interface units 330, the line side interface connection unit 339 demaps the other line side interface unit 330 in which the OTUCn frame designated as the arrangement change target is designated. The OTUCn frame that is not designated as the target of the arrangement change is output to the demapping unit 340 of the same line side interface unit 330 as the output source. When the arrangement of the OTUCn frame is not changed, the line side interface connection unit 339 outputs the OTUCn frame to the demapping unit 340 of the line side interface unit 330 that is the same as each output source.

  The demapping unit 340 extracts the ODTU signal assigned to the payload area of the OTUCn frame input from the line side interface connection unit 339. The demapping unit 340 outputs the extracted ODTU signal to the backplane interface unit 331 as a signal addressed to the client side interface unit 310 corresponding to the ODTU signal. The signal output from the demapping unit 340 is transmitted to the destination client side interface unit 310 via the backplane interface unit 331 and the backplane unit 320.

  FIG. 6 is a diagram illustrating a flow of information in mapping and OTUCn frame arrangement change in the optical transmission apparatus 30. In the example shown in the figure, the optical transmission device 30 includes four client-side interface units 310-1 to 310-4 and two line-side interface units 330-1 and 330-2. Each of the four client side interface units 310-1 to 310-4 outputs the ODTU signals Sig1 to Sig4 to the backplane unit 320, and the ODTU signals Sig1 and Sig2 are input to the line side interface unit 330-1, and the ODTU signal Sig3 and Sig4 is input to the line side interface unit 330-2. Each of the line side interface units 330-1 and 330-2 transmits two OTUC2 frames at two output wavelengths.

  In the line side interface unit 330-1, the virtual map calculation unit 332 has the ODTU signals Sig1 and Sig2 based on the data amount of the input ODTU signals Sig1 and Sig2, the ratio of the bit rate between the client side and the line side, and the like. Is mapped to determine the accommodation position and stuff position of each signal when the signal is accommodated in two OTUCn frames. Further, the virtual map calculation unit 332 determines to output the OTUC2 frame including only a part of the ODTU signal Sig1 to the line side interface unit 330-2 based on the output wavelength constraint. The mapping unit 333 accommodates the ODTU signals Sig1 and Sig2 in two OTUC2 frames based on the virtual mapping result by the virtual map calculation unit 332, and outputs them to the line side interface connection unit 334.

  In the line side interface unit 330-2, the virtual map calculation unit 332 has the ODTU signals Sig3 and Sig4 based on the data amount of the input ODTU signals Sig3 and Sig4, the ratio of the bit rate between the client side and the line side, and the like. Is mapped to determine the accommodation position of each signal and the stuff position when it is accommodated in two OTUC2 frames. Also, the virtual map calculation unit 332 determines to output the OTUC2 frame including only a part of the ODTU signal Sig3 to the line side interface unit 330-1 based on the output wavelength constraint. The mapping unit 333 accommodates the ODTU signals Sig3 and Sig4 in two OTUC2 frames based on the virtual mapping result by the virtual map calculation unit 332, and outputs them to the line side interface connection unit 334.

  The line-side interface connection unit 334 generates an OTUC2 frame including only a part of the ODTU signal Sig1 and the ODTU signal Sig3 based on the determination of the arrangement change by the virtual map calculation unit 332 of the line-side interface units 330-1 and 330-2. Exchange is performed to output the OTUC2 frame including only a part to the other line side interface unit 330. The OTUC2 frame including a part of the ODTU signals Sig2 and Sig1 and the OTUC2 frame including only a part of the ODTU signal Sig3 are input to the transmission-side overhead / FEC processing unit 335 of the line-side interface unit 330-1. The OTUC2 frame including only a part of the ODTU signal Sig1 and the OTUC2 frame including a part of the ODTU signal Sig3 and Sig4 are input to the transmission side overhead / FEC processing unit 335 of the line side interface unit 330-2.

  Two OTUC2 frames input to the transmission side overhead / FEC processing unit 335 of the line side interface unit 330-1 and two OTUC2 frames input to the transmission side overhead / FEC processing unit 335 of the line side interface unit 330-2 Is modulated every 100 Gbit / s and output as a four-wave optical signal. As for reception, the four ODU signals Sig1 to Sig4 are demodulated and decoded from the four-wave optical signals in the reverse order to the description regarding the transmission and output to the client side interface units 310-1 to 310-4. . The reception-side overhead / FEC processing unit 338 performs a deskew process that absorbs a delay difference between the four-wave optical signals.

  As described above, according to the optical transmission device 30 of the first embodiment, the OTUCn frame accommodating the OTDU signal is exchanged between the line side interface units 330 using the line side interface connection units 334 and 339. Thus, the OTDU signal (or client signal) can be accommodated in the OTUCn frame across the line side interface unit 330.

(Second Embodiment)
FIG. 7 is a block diagram illustrating a configuration example of the optical transmission device 40 according to the second embodiment. As shown in the figure, the optical transmission device 40 includes a plurality of client side interface units 410 (410-1 to 410-k), a backplane unit 320, and two line side interface units 430 (430-1 and 430-2). ). The client side interface unit 410 is provided according to the number of client signals to be accommodated. In the optical transmission apparatus 40, the same components as those included in the optical transmission apparatus 30 shown in FIG. 1 or the optical transmission apparatus 90 shown in FIG. . In the configuration example illustrated in FIG. 7, the optical transmission device 40 includes two line-side interface units 430, but may include three or more line-side interface units 430.

  In the optical transmission apparatus 40, the client-side interface unit 410 corresponds to the client signal receiving unit 120 and the client signal transmitting unit 180 in FIG. The backplane unit 320 corresponds to the ODU-SW 210 in FIG. Each of the line side interface units 430-1 and 430-2 corresponds to the multiplex processing unit 130, the line side transmission processing unit 140, the transmitter 220, the receiver 230, the line side reception processing unit 160, and the separation processing unit 170 in FIG. To do.

  Each of the client side interface units 410 receives a client signal from an external device, and generates an ODTU signal as an LO-ODU including the received client signal. The client-side interface unit 410 generates an ODTU signal by mapping a client signal for the data capacity specified in the transfer instruction information to the payload of the ODTU signal and adding an ODTU OH. The client side interface unit 410 outputs an ODTU signal addressed to the line side interface unit 430 specified in the transfer instruction information to the backplane unit 420. The client side interface unit 410 acquires transfer instruction information from the line side interface unit 430 via the backplane unit 420.

  Each of the client side interface units 410 inputs an ODTU signal from the line side interface unit 430 via the backplane unit 420. The client side interface unit 410 extracts a client signal from the input ODTU signal, and outputs the extracted client signal to an external device.

  The backplane unit 420 interconnects the plurality of client side interface units 410 and the two line side interface units 430, and exchanges ODTU signals and transfer instruction information.

  Each of the line side interface units 430 generates transfer instruction information from the information of the ODTU signal input via the backplane unit 420, and transfers the generated transfer instruction information to the client side interface unit 410 via the backplane unit 420. Output information. Further, the line side interface unit 430 generates an ODUCn frame from the ODTU signal input via the backplane unit 420. The line side interface unit 430 transmits an optical signal obtained by performing electro-optical conversion on the electric signal of the ODUCn frame. Further, the line side interface unit 430 restores the ODTU signal from the electrical signal of the ODUCn frame obtained by performing the optical-electrical conversion on the received optical signal. The line side interface unit 430 outputs the restored ODTU signal to the associated client side interface unit 410 via the backplane unit 420.

  The line side interface unit 430 includes a backplane interface unit 431, a virtual map calculation unit 432, a mapping unit 433, a transmission side overhead / FEC processing unit (transmission side OH-FEC processing unit) 435, a transmission unit 336, and a reception unit 337. A receiving side overhead / FEC processing unit (receiving side OH-FEC processing unit) 438 and a demapping unit 440.

  The backplane interface unit 431 outputs information related to the ODTU signal input from the client side interface unit 410 via the backplane unit 420 to the virtual map calculation unit 432. The information related to the ODTU signal includes an ODTU signal identifier, a data amount, an address where the ODTU signal in the client side interface unit 410 is stored, a payload type, client side time information, and the like. The backplane interface unit 431 outputs the transfer instruction information input from the virtual map calculation unit 432 to each of the client side interface units 410 via the backplane unit 420.

  In addition, the backplane interface unit 431 outputs the ODTU signal input from the client side interface unit 410 via the backplane unit 420 to the mapping unit 433. Further, the backplane interface unit 431 outputs the ODTU signal input from the demapping unit 440 to the backplane unit 420 as a signal addressed to the client side interface unit 410 specified as the destination of the ODTU signal.

  The virtual map calculation unit 432 performs virtual mapping based on information regarding the ODTU signal input via the backplane interface unit 431. The virtual map calculation unit 432 calculates the bit rate and the ratio of each of the client side interface unit 410 and the line side interface unit 430 based on the input information. The virtual map calculation unit 432 uses the calculated bit rate and ratio, and the input information, to determine the ITU-T G. The number of client data entities Cm and ΣCnD for the OTUCn frame determined in 709 is calculated. The virtual map calculation unit 432 calculates the calculated client data entity numbers Cm and ΣCnD and the ITU-T G.D. The GMP mapping image of the ODTU signal input to the line side interface units 430-1 and 430-2 is generated by the GMP mapping algorithm defined in 709. That is, the virtual map calculation unit 432 virtually maps the ODTU signal to an OTUCn frame that spans a plurality of wavelengths.

  ITU-T G. Even when the payload area of the OTUCn frame extends over a plurality of output wavelengths by the GMP mapping algorithm defined in 709, if the accommodation order of the ODTU signal in the tributary slot (or time slot) is determined, The accommodation position and the staff position in the OTUCn frame of the ODTU signal are uniquely determined. Further, by using the accommodation order of the tributary slots at each output wavelength and the client data entities Cm and ΣCnD, independent GMP mapping is possible for each output wavelength.

  Therefore, for each line-side interface unit 430 that transmits an OTUCn frame, the identifier of the line-side interface unit 430 and the address of the ODTU signal to be accommodated are extracted from the GMP mapping image, and are converted into the GMP mapping image for the client-side interface unit 410. In addition, by outputting the client signal to the line-side interface unit 430, the client signal can be accommodated and transmitted in an OTUCn frame extending over a plurality of output wavelengths.

  The line-side interface unit 430 can directly generate an output OTUCn frame from the received ODTU signal, the number of client data entities Cm and ΣCnD, and the accommodation order of the tributary slots. The transfer of the OTUCn frame can be made unnecessary.

  The virtual map calculation unit 432 generates transfer instruction information based on the generated GMP mapping image and the output wavelength of the transmission unit 336, and transmits the generated transfer instruction information via the backplane interface unit 431 and the backplane unit 420. The data is output to the client side interface unit 410. The transfer instruction information includes an identifier of the line side interface unit 430 and an address table of an ODTU signal corresponding to the client signal output to the line side interface unit 430 of the identifier.

  The mapping unit 433 acquires the ODTU signal output from the client side interface unit 410 via the backplane unit 420 and the backplane interface unit 431. The mapping unit 433 performs mapping that accommodates the ODTU signal in the OTUCn frame based on the GMP mapping image generated by the virtual map calculation unit 332. The mapping unit 433 outputs the OTUCn frame containing the ODTU signal to the transmission-side overhead / FEC processing unit 435. The transmission-side overhead / FEC processing unit 435 adds overhead and FEC to the OTUCn frame input from the mapping unit 433 and outputs the result to the transmission unit 336.

  The receiving-side overhead / FEC processing unit 438 performs error correction decoding using the FEC added to the OTUCn frame output from the receiving unit 337 and then extracts the payload area of the OTUCn frame. The reception-side overhead / FEC processing unit 438 outputs the extracted payload area of the OTUCn frame to the demapping unit 440.

  The demapping unit 440 extracts the ODTU signal assigned to the payload area of the OTUCn frame output from the receiving side overhead / FEC processing unit 438. The demapping unit 440 outputs the extracted ODTU signal to the backplane interface unit 431 as a signal addressed to the client side interface unit 410 corresponding to the ODTU signal. The signal output from the demapping unit 440 is transmitted to the destination client side interface unit 410 via the backplane interface unit 431 and the backplane unit 420.

  FIG. 8 is a diagram illustrating a flow of information in the virtual mapping and transfer instruction information generation process in the optical transmission device 40. In the example in the figure, the optical transmission device 40 includes four client side interface units 410-1 to 410-4 and two line side interface units 430-1 and 430-2. Each of the line side interface units 430-1 and 430-2 transmits and receives optical signals having two different output wavelengths. The four client side interface units 410-1 to 410-4 each output a signal related to the ODTU signals Sig 1 to Sig 4 to the backplane unit 420.

  In the line side interface units 430-1 and 430-2, the virtual map calculation unit 432 converts the ODTU signals Sig1 to Sig4 into the payload area of the OTUCn frame based on the information about the ODTU signal output from each of the client side interface units 410. Perform virtual mapping. As a result of the virtual mapping, the ODTU signal Sig1 is arranged across two OTUCn frames. Further, the ODTU signal Sig3 is also arranged across the two OTUCn frames.

  FIG. 9 is a diagram illustrating an example of an address table obtained from the result of virtual mapping. As shown in the figure, the ODTU signal Sig2 output from the client side interface unit 410-1 as a result of the virtual mapping is accommodated in the tributary slot 520 of the OTUCn frame 501. The ODTU signal Sig1 output from the client side interface unit 410-2 is accommodated in the tributary slot 510 that straddles the OTUCn frames 501 and 502.

  When it is determined that the OTUCn frame 501 is output to the line-side interface unit 430-1 and the OTUCn frame 502 is output to the line-side interface unit 430-2 due to output wavelength restrictions or the like, the slot of the tributary slot 520 The virtual map calculation unit 432 generates transfer instruction information for outputting the data in the region 521 and the slot region 511 of the tributary slot 510 to the line side interface unit 430-1. Also, the virtual map calculation unit 432 generates transfer instruction information for outputting the data in the slot areas 512 and 513 of the tributary slot 510 to the line side interface unit 430-2.

  As shown in FIG. 9, the address table includes items of “client side I / F”, “line side I / F”, “tributary slot area”, “tributary slot accommodation order”, and “client buffer address”. Have. “Client side I / F” indicates a corresponding client side interface unit 410, and “Line side I / F” indicates a corresponding line side interface unit 430. The “tributary slot area” indicates a tributary slot in which an ODTU signal output from the client side interface unit 410 to the line side interface unit 430 is accommodated. “Tributary slot accommodation order” is an order in which ODTU signals are accommodated in the tributary slot, and is determined by setting / control information from the outside. The “client buffer address” is an address at which data accommodated in the corresponding tributary slot area is stored in a buffer included in the client side interface unit 410.

  The virtual map calculation unit 432 performs virtual GMP mapping before the mapping unit 433 performs actual mapping in which the ODTU signal is accommodated in the OTUCn frame, and generates an address table based on the GMP mapping result. The virtual map calculation unit 432 outputs transfer instruction information to each of the client side interface units 410 included in the generated address table. In the example illustrated in FIG. 9, the data stored in the buffer address “0x000-0x0ff” is output to the line side interface unit 430-2 as an ODTU signal to the client side interface unit 410-1, The data stored in the buffer address “0x100-0x1ff” is output as an ODTU signal to the line side interface unit 430-1, and then the data stored in the buffer address “0x200-0x2ff” is output to the line side interface unit 430. -2 is output to the transfer instruction information instructing to be output as an ODTU signal to -2.

  FIG. 10 is a diagram showing an outline of an OTUCn frame generated by the line side interface unit 430 based on the result of the virtual mapping and transfer instruction information generation process shown in FIG. Each of the client side interface units 410-1 to 410-4 sends an OTDU signal containing a client signal to the line side interface units 430-1 and 430-2 based on the transfer instruction information output from the virtual map calculation unit 432. Output.

  As shown in FIG. 10, the client side interface unit 410-1 divides the client signal into two OTDU signals Sig1a and Sig1b, outputs the OTDU signal Sig1a to the line side interface unit 430-1, and outputs the ODTU signal Sig1b to the line. To the side interface unit 430-2. The client side interface unit 410-2 outputs an ODTU signal Sig2 containing the client signal to the line side interface unit 430-1. The client side interface unit 410-3 divides the client signal into two ODTU signals Sig3a and Sig3b, outputs the ODTU signal Sig3a to the line side interface unit 430-1, and sends the ODTU signal Sig3b to the line side interface unit 430-2. Output. The client side interface unit 410-4 outputs the ODTU signal Sig4 containing the client signal to the line side interface unit 430-2.

  The line side interface unit 430-1 generates an OTUCn frame containing the ODTU signals Sig2 and Sig1a and an OTUCn frame containing the ODTU signal Sig3, and transmits the generated OTUCn frames as optical signals having output wavelengths λ1 and λ3, respectively. To do. The line-side interface unit 430-2 generates an OTUCn frame containing the ODTU signal Sig1b and an OTUCn frame containing the ODTU signals Sig3b and Sig4, and outputs the generated OTUCn frames to the optical signals having the output wavelengths λ2 and λ4 Send with. The reception process is the reverse of the above-described transmission process.

  As described above, according to the optical transmission device 40 in the second embodiment, the virtual map calculation unit 432 acquires information on the transmission target ODTU signal from each of the client side interface units 410 and virtually performs GMP mapping. Do. The virtual map calculation unit 432 determines allocation of accommodation of the OTDU signal to the OTUCn frame based on the result of the GMP mapping and the restriction on the line side interface unit 430 (for example, restriction on the output wavelength, etc.). And output the transfer instruction information to each of the client side interface units 410. Each of the client side interface units 410 outputs an OTDU signal containing a client signal to the line side interface unit 430 based on the transfer instruction information. By such an operation, the client signal across the line side interface unit 430 can be accommodated in the OTUCn frame by the distribution of the OTDU signal by the client side interface unit 410 and the distribution of the OTDU signal in the backplane unit 420. can do.

  In the optical transmission device 30 according to the first embodiment, the OTUCn frames are exchanged between the line side interface units 430. Since the exchange of the OTUCn frame in the line side interface unit 430 requires substantially the same bandwidth as the input / output bandwidth of the line side interface unit 430, the processing in the line side interface connection units 334 and 339 is twice the input / output bandwidth. Bandwidth is required. Since it is difficult for the line-side interface unit 430 operating at a high speed to process a band twice as large as the input / output band, the line-side interface unit 430 is limited by the band in the line-side interface connection units 334 and 339. In some cases, it may be difficult to accommodate a client signal straddling the OTUCn frame. On the other hand, in the optical transmission device 40, since it is not necessary to exchange the OTUCn frame between the line side interface units 430, there is no restriction as described above, so that the OTUCn frame of the client signal straddling the line side interface unit 430 is transferred. Can be easily accommodated.

  In the optical transmission device 40 of the second embodiment, the GMP mapping result or the transfer instruction information calculated by the virtual map calculation unit 432 is transmitted to the opposite device (receiving optical transmission device 40) of the optical transmission device 40 as a control plane. Or you may notify using the overhead of an OTUCn frame. The notified GMP mapping result or transfer instruction information is used to specify the client-side interface unit 410 that is the output destination of the ODTU signal extracted by the demapping unit 440. Similarly to the optical transmission device 30, the optical transmission device 40 includes a control signal transmission unit and a control signal reception unit, and the control signal transmission unit and the control signal reception unit transmit and receive a control plane or an OTUCn frame. Good.

In the optical transmission device in each embodiment, the number of client data entities Cm and ΣCnD and the order in which the tributary slots are accommodated may be included in the transfer instruction information and the OTDU signal.
In each embodiment, the configuration in which the optical transmission device includes two line-side interface units has been described. However, the optical transmission device may have a configuration including three or more line-side interface units.

  The optical transmission device in the above-described embodiment may be realized by a computer. In that case, it is realized by recording a program for realizing each component included in the optical transmission apparatus on a computer-readable recording medium, causing the computer system to read and execute the program recorded on the recording medium. May be. Here, the “computer system” includes an OS and hardware such as peripheral devices. The “computer-readable recording medium” refers to a storage device such as a flexible medium, a magneto-optical disk, a portable medium such as a ROM and a CD-ROM, and a hard disk incorporated in a computer system. Further, the “computer-readable recording medium” is a program that dynamically holds a program for a short time, like a communication line when a program is transmitted via a network such as the Internet or a communication line such as a telephone line. In this case, a volatile memory inside a computer system serving as a server or a client in that case may be included and a program held for a certain period of time. Further, the program may be for realizing a part of the above-described constituent elements, and may be realized by combining the above-described constituent elements with a program already recorded in a computer system. It may be realized by using hardware such as PLD (Programmable Logic Device) or FPGA (Field Programmable Gate Array).

  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.

  It can also be applied to applications where mapping of client signals across a plurality of line side interface units is indispensable.

DESCRIPTION OF SYMBOLS 30, 40, 90 ... Optical transmission apparatus 100 ... Framer 110 ... Transmission processing part 120 ... Client signal receiving part 121 ... Reception part 122 ... Mapping part 123 ... OH processing part 130 ... Multiplexing part 131 ... Multiplexing part 132 ... Framing part 140 ... line side transmission processing unit 141 ... interleaving unit 142, 142-1, 142-2, 142-3, 142-4, 142-i ... OH processing unit 143, 143-1, 143-2, 143-3 143-4, 143-i ... multilane transmission unit 150 ... reception processing unit 160 ... line side reception processing unit 161-1, 161-2, 161-3, 161-4, 161-i ... multilane reception unit 162 1, 162-2, 162-3, 162-4, 162-i ... OH processing unit 163 ... deinterleaving unit 170 ... separation processing unit 171 Deframing portion 172 ... demultiplexer 180 ... client signal transmitting unit 181 ... OH processing unit 182 ... demapper 183 ... transmitting portion 210 ... ODU-SW
220 ... Transmitter 230 ... Receiver 310, 310-1, 310-2, 310-3, 310-4, 310-k, 410, 410-1, 410-2, 410-3, 410-4, 410- k: Client side interface unit 320, 420 ... Backplane unit 330, 330-1, 330-2, 430, 430-1, 430-2 ... Line side interface unit 331, 431 ... Backplane interface unit 332, 432 ... Virtual map calculation unit 333, 433, 933 ... mapping unit 334, 339 ... line side interface connection unit 335, 435, 935 ... transmission side overhead / FEC processing unit 336 ... transmission unit 337 ... reception unit 338, 438, 938 ... reception side Overhead / FEC processing unit 340, 440, 940 ... Demappi 341 ... Control signal transmission unit 342 ... Control signal reception unit 510,520 ... Tributary slot 511,512,513,521 ... Slot area 930,930-1,930-2 ... Line side interface unit

Claims (5)

A plurality of client side interface units for inputting / outputting ODTU signals containing client signals, a plurality of line side interface units for inputting / outputting OTUCn frames contained in optical signals, a plurality of the client side interface units, An optical transmission device including a backplane unit that exchanges an ODTU signal with a line-side interface unit,
The line side interface unit is
Information on the ODTU signal is acquired from the client side interface unit via the backplane unit, and the ODTU signal is virtually mapped to an OTUCn frame spanning a plurality of wavelengths based on the information on the ODTU signal. A virtual map calculation unit that generates transfer instruction information for requesting the client-side interface unit to output an ODTU signal containing a client signal.
A mapping unit that maps an ODTU signal output from the client-side interface unit according to the transfer instruction information to an OTUCn frame based on the mapping result;
A transmitter that optically modulates and outputs an OTUCn frame in which the ODTU signal is mapped by the mapping unit;
An optical transmission device comprising: The optical transmission device according to claim 1,
The line side interface unit is
An optical receiver that outputs an OTUCn frame obtained by optically demodulating an optical signal output from another optical transmission device;
A demapping unit that outputs an ODTU signal extracted by demapping the OTUCn frame output from the optical receiving unit to the client side interface unit;
An optical transmission device, further comprising: A plurality of client side interface units for inputting / outputting ODTU signals containing client signals, a plurality of line side interface units for inputting / outputting OTUCn frames contained in optical signals, a plurality of the client side interface units, An optical transmission device comprising a backplane unit that exchanges an ODTU signal with a line side interface unit, and a line side interface connection unit that connects the plurality of line side interface units,
The line side interface unit is
A virtual map for acquiring an ODTU signal and information related to the ODTU signal from the client-side interface unit via the backplane unit, and determining an accommodation position and a staff position when accommodating the ODTU signal in an OTUCn frame spanning a plurality of wavelengths. A calculation unit;
A mapping unit that maps the ODTU signal acquired from the client side interface unit to the OTUCn frame via the backplane unit based on the accommodation position and the staff position determined by the virtual map calculation unit;
A transmitter that optically modulates and outputs an OTUCn frame in which the ODTU signal is mapped by the mapping unit;
With
The virtual map calculation unit
When there is a restriction to use an optical signal having a specific wavelength for the transmission of the ODTU signal, the ODTU signal is accommodated to the line-side interface unit including a transmission unit that transmits an optical signal that satisfies the restriction. An optical transmission device that performs control to transfer an OTUCn frame to the line-side interface connection unit. A plurality of client side interface units for inputting / outputting an ODTU signal accommodating a client signal, a plurality of line side interface units for inputting / outputting an OTUCn frame accommodated in an optical signal, a plurality of the client side interface units, and a plurality of the plurality of the interface units An optical transmission method in an optical transmission device including a backplane unit that exchanges an ODTU signal with a line-side interface unit,
The line-side interface unit acquires information about the ODTU signal from the client-side interface unit via the backplane unit, and virtually converts the ODTU signal into an OTUCn frame that spans multiple wavelengths based on the information about the ODTU signal. A first step of mapping and generating transfer instruction information for requesting the client side interface unit to output an ODTU signal containing a client signal based on the mapping result;
A second step in which the client-side interface unit outputs an ODTU signal to the line-side interface unit according to the transfer instruction information;
A third step in which the line side interface unit maps an ODTU signal output from the client side interface unit to an OTUCn frame based on the mapping result;
A fourth step in which the line side interface unit optically modulates and outputs the OTUCn frame to which the ODTU signal is mapped in the third step;
An optical transmission method comprising: A plurality of client side interface units for inputting / outputting an ODTU signal accommodating a client signal, a plurality of line side interface units for inputting / outputting an OTUCn frame accommodated in an optical signal, a plurality of the client side interface units, and a plurality of the plurality of the interface units An optical transmission method in an optical transmission device comprising: a backplane unit that exchanges an ODTU signal with a line side interface unit; and a line side interface connection unit that connects the plurality of line side interface units,
The line-side interface unit acquires an ODTU signal and information related to the ODTU signal from the client-side interface unit via the backplane unit, and an accommodation position when accommodating the ODTU signal in an OTUCn frame spanning a plurality of wavelengths, and A first step of determining staff positions;
The line side interface unit maps the ODTU signal acquired from the client side interface unit to the OTUCn frame via the backplane unit based on the accommodation position and the staff position determined in the first step. Steps,
A third step in which the line side interface unit optically modulates and outputs the OTUCn frame to which the ODTU signal is mapped in the second step;
When the line-side interface unit is provided with a constraint that uses an optical signal having a specific wavelength for transmission of an ODTU signal, the line-side interface unit includes a transmission unit that transmits an optical signal that satisfies the constraint. A fourth step of performing control to transfer an OTUCn frame accommodating the ODTU signal to the line side interface connection unit;
An optical transmission method comprising:

Images