TRANSMISSION SYSTEM, TRANSMITTER, RECEIVER, AND METHOD

Abstract

To provide a transmission system, a transmission device, a reception device, and a method that can efficiently utilize a transmission bandwidth.SOLUTION: A transmission device 3000 that uses OTN includes mapping means 3001 that maps a first client signal to an ODU payload area by GMP and maps a second client signal that is different from the first client signal to another area of the ODU payload area.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The present disclosure relates to a transmission system, a transmitting device, a receiving device, a transmitting method, and a receiving method. [Background technology]

[0002] ITU-T G.709 OTN (Optical Transport Network) is a communication standard that maps client signals based on Ethernet and SONET / SDH (Synchronous Optical Network / Synchronous Digital Hierarchy) to ODU (Optical Data Unit) signals for transmission.

[0003] In OTN-based transmission systems, when mapping a low-speed client signal to a high-speed ODU signal, it is necessary to adjust the bit rate of the client signal and the bit rate of the ODU signal. GMP (Generic Mapping Procedure) is defined as one of the mapping methods that can be applied in such cases.

[0004] For example, Patent Document 1 describes a method for mapping client signals based on GMP. In the method described in Patent Document 1, in order to simplify the mapping process, part or all of the payload area of ​​an OPU or ODTU is divided into several sub-blocks, each having a size of N bytes. Client signals to be transmitted are mapped to the sub-blocks of the payload area with an N-byte granularity. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2010 / 091604 Summary of the Invention [Problem to be solved by the invention]

[0006] In GMP, the difference in bit rate between the client signal and the ODU signal is adjusted by inserting stuff bytes (all 0 data) into the payload portion of the OPU. However, when the difference in bit rate between the ODU signal and the client signal is large, the stuff bytes occupy most of the payload portion of the ODU signal. As a result, the utilization efficiency of the ODU signal decreases. For example, even if the mapping method described in Patent Document 1 is applied, it is not possible to improve such a decrease in utilization efficiency.

[0007] An object of the present disclosure is to provide a transmission system, a transmitting device, a receiving device, and a method that can efficiently utilize a transmission band. [Means for solving the problem]

[0008] A transmitting device according to the present disclosure is a transmitting device that uses OTN, and maps a first client signal to an ODU payload area by GMP, and The first client signal is not mapped. In the area , instead of staff part-timers, The radio communication system is characterized by comprising a mapping means for mapping a second client signal different from the first client signal.

[0009] A receiving device according to the present disclosure is a receiving device that uses OTN, and in which a first client signal is mapped to an ODU payload area by GMP, and The first client signal is not mapped. In the area Instead of staff part-timers The optical fiber communication system is characterized by comprising a demapping means for extracting the first client signal and the second client signal from an ODU signal to which a second client signal different from the first client signal is mapped.

[0010] The transmission system according to the present disclosure maps a first client signal to an ODU payload area by GMP and The first client signal is not mapped. In the area , instead of staff part-timers,a transmitting device including a mapping unit that maps a second client signal different from the first client signal; and a transmitting device in which the first client signal is mapped to an ODU payload area by GMP and the second client signal is mapped to the ODU payload area by GMP. The first client signal is not mapped. In the area Instead of staff part-timers The present invention is characterized by comprising a receiving device including a demapping means for extracting a first client signal and a second client signal from an ODU signal to which a second client signal different from the first client signal is mapped.

[0011] The transmission method according to the present disclosure is a transmission method using OTN, which maps a first client signal to an ODU payload area by GMP and The first client signal is not mapped. In the area , instead of staff part-timers, A second client signal different from the first client signal is mapped.

[0012] The receiving method according to the present disclosure is a receiving method using OTN, in which a first client signal is mapped to an ODU payload area by GMP, and The first client signal is not mapped. In the area Instead of staff part-timers The first client signal and the second client signal, which are different from the first client signal, are extracted from an ODU signal to which the second client signal is mapped. [Effects of the Invention]

[0013] According to the present disclosure, transmission bands can be used efficiently. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a block diagram showing an example of the configuration of a general OTN transmission / reception system. [Figure 2] FIG. 10 is a diagram illustrating an example in which an STM-1 signal is mapped to an ODU0 frame. [Figure 3]1 is a block diagram showing an example of the configuration of an embodiment of an OTN transmission / reception system 100. FIG. [Figure 4] 10 is a flowchart showing the processing operation of the OTN transmitter 300 in the OTN transceiver system 100. [Figure 5] 10 is a flowchart showing the processing operation of the OTN receiving device 400 in the OTN transmitting and receiving system 100. [Figure 6] 10 is a diagram showing an image of an ODU frame when a client signal: STM-1 and a second client signal: GbE are mapped to ODU0 in the OTN transmission / reception system 100. FIG. [Figure 7] FIG. 1 is a block diagram illustrating an example in which the configuration of the present disclosure is applied to a 5G base station device. [Figure 8] 1 is a block diagram illustrating an overview of a transmission device according to the present disclosure. [Figure 9] 1 is a block diagram illustrating an overview of a receiving device according to the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.

[0016] First, we will explain a general transmission method using OTN. In OTN, various bit rates are defined for ODUs, such as ODU0 (1.25 Gbps), ODU1 (2.5 Gbps), ODU2 (10 Gbps), ODU25 (25 Gbps), and ODUflex (any bit rate above 1.25 Gbps). Furthermore, in OTN, it is possible to map a low-speed ODU (LO ODU: Low Order ODU) to a higher-speed ODU (HO ODU: High Order ODU). The minimum unit for ODU mapping is 1.25 Gbps. Therefore, for example, when a client signal of 1.25 Gbps or less is mapped to ODU0, the client signal and stuff bytes (all 0 data) occupy the entire 1.25 Gbps bandwidth of ODU0. In the following explanation, Ethernet, SONET / SDH, and LO ODU are referred to as "client signals," and the HO ODU, the ODU to which the signal is mapped, is referred to as "ODU signals."

[0017] When an ODU signal is transmitted, an OTU OH (Optical channel Transport Unit (OTU) Overhead) is added to the ODU signal and FEC (Forward Error Correction) coding is performed to form an OTU frame. When an ODU signal is received, after OTU frame synchronization, FEC decoding is performed to separate the OTU OH and the ODU signal. Furthermore, when processing these OTU frames, processing may be performed to map or demap the ODU signal to a higher-speed ODU. Note that the processing for transmitting and receiving these ODU signals is omitted in the following explanation.

[0018] An ODU signal consists of an ODU Over Head (ODU OH), which is additional information for transmission, and an Optical Payload Unit (OPU) to which a client signal is mapped. The OPU consists of an OPU Over Head (OPU OH), which indicates information about the mapped client signal, and a payload that contains the client signal. The OPU OH also has a Payload Structure Identifier (PSI). The PSI makes it possible to transmit information about the signal contained in the OPU payload.

[0019] PSI transmits 1 byte of data per frame in 256 multi-frames, allowing for the transmission of 256 bytes of information. Of the 256 bytes of PSI, 1 byte is assigned to the payload type (PT) and 1 bit to the client signal fail (CSF). The remaining areas in PSI are reserved.

[0020] When mapping a low-speed client signal to a high-speed ODU signal, it is necessary to adjust the bit rate of the client signal and the bit rate of the ODU signal. For example, the above-mentioned GMP can be used as a mapping method applicable in such cases.

[0021] GMP adjusts the difference in bit rate between the client signal and the ODU signal by inserting stuff bytes (all 0 data) into the payload of the OPU. GMP also inserts information into the OPU OH indicating the insertion position of the stuff bytes inserted into the payload of the OPU.

[0022] However, as described above, when the difference in bit rate between the ODU signal and the client signal is large, the stuff bytes occupy most of the payload portion of the ODU signal, and the utilization efficiency of the ODU signal decreases.

[0023] Fig. 1 is a block diagram showing an example of the configuration of a general OTN transmission and reception system. As shown in Fig. 1, the general OTN transmission and reception system includes an OTN transmitter 3 that receives a client signal from a client transmitter 1 and transmits an OTN signal, and an OTN receiver 4 that is connected to the OTN transmitter 3 via a transmission line, receives the OTN signal, and supplies the client signal to a client receiver 2.

[0024] The OTN transmitter 3 shown in FIG. 1 includes a client signal receiver 31, an ODU clock generator 32, a mapping controller 33, an OPU OH generator , a transmission selector 35, and an ODU frame generator .

[0025] The client signal receiving unit 31 receives the client signal transmitted by the client transmitting device 1. Then, the client signal receiving unit 31 outputs data of the client signal (hereinafter also referred to as client data) to the transmission selecting unit 35. The client signal receiving unit 31 also extracts a client clock from the client signal. Then, the client signal receiving unit 31 outputs the extracted client clock to the mapping control unit 33.

[0026] The ODU clock generating unit 32 generates an ODU clock based on, for example, the basic clock of the OTN transmission device 3. Then, the ODU clock generating unit 32 outputs the generated ODU clock to the mapping control unit 33 and the ODU frame generating unit .

[0027] The mapping control unit 33 determines the number of bytes of client data to be inserted into an ODU frame based on the difference in frequency between the client clock extracted by the client signal receiving unit 31 and the ODU clock generated by the ODU clock generating unit 32. Then, the mapping control unit 33 outputs information indicating the determined number of bytes of client data to the OPU OH generating unit 34. The OPU OH generating unit 34 inserts the information into the OH (Overhead) of the OPU frame.

[0028] Furthermore, the mapping control unit 33 generates a selection signal based on the determined number of bytes of client data and outputs it to the transmission selection unit 35. This selection signal is a signal that indicates whether the signal to be inserted into the OPU data is client data or stuff bytes.

[0029] Various methods can be applied to generate the selection signal. For example, the mapping control unit 33 can identify the position where the client data is to be inserted and the position where the stuff byte is to be inserted based on the determined number of bytes of the client data, as exemplified in Fig. 2. Based on the result of this identification, the mapping control unit 33 may generate a selection signal indicating whether the signal to be inserted into the OPU data is client data or stuff bytes.

[0030] The OPU OH generation unit 34 generates an OPU OH based on information indicating the number of bytes of client data determined by the mapping control unit 33. Then, the OPU OH generation unit 34 outputs the generated OPU OH to the ODU frame generation unit 36.

[0031] The transmission selector 35 selects either the client data or the stuff bytes output by the client signal receiver 31 based on the selection signal generated by the mapping controller 33. The transmission selector 35 outputs the selected data to the ODU frame generator 36 as OPU data.

[0032] The ODU frame generation unit 36 ​​generates an ODU frame by inserting the OPU OH output by the OPU OH generation unit 34 into the OPU data output by the transmission selection unit 35. Then, the ODU frame generation unit 36 ​​transmits the generated ODU frame to the OTN receiving device 4.

[0033] The OTN receiver 4 shown in FIG. 1 includes a client signal transmitter 41, a demapping controller 43, an OPU OH processor 44, a selector for reception 45, and an ODU frame processor 46.

[0034] The ODU frame processing unit 46 receives the ODU frame transmitted by the OTN transmission device 3. The ODU frame processing unit 46 extracts OPU data, an ODU clock, and an OPU OH from the received ODU frame. The ODU frame processing unit 46 outputs the extracted OPU data to the reception selection unit 45. The ODU frame processing unit 46 outputs the extracted ODU clock to the demapping control unit 43. The ODU frame processing unit 46 outputs the extracted OPU OH to the OPU OH processing unit 44.

[0035] The OPU OH processing unit 44 identifies the number of bytes of the client data in the ODU frame based on the OPU OH. The OPU OH processing unit 44 outputs the identified number of bytes of the client data to the demapping control unit 43.

[0036] The demapping control unit 43 generates a selection signal based on the ODU clock and the number of bytes of the client data. The demapping control unit 43 outputs the generated selection signal to the reception selection unit 45.

[0037] The demapping control unit 43 also generates a client clock based on the ODU clock and the number of bytes of the client data. The demapping control unit 43 outputs the generated client clock to the client signal transmitting unit 41.

[0038] The reception selection unit 45 extracts client data from the OPU data and discards stuff bytes based on the selection signal generated by the demapping control unit 43. The reception selection unit 45 outputs the extracted client data to the client signal transmission unit 41.

[0039] The client signal transmitting unit 41 generates a client signal based on the client data extracted by the reception selecting unit 45 and the client clock generated by the demapping control unit 43. That is, the client signal transmitting unit 41 regenerates the client signal. The client signal transmitting unit 41 transmits the regenerated client signal to the client receiving device 2.

[0040] In the above-mentioned general OTN transmission / reception system, a case will be described in which the client signal is a 155.52 Mbps STM-1 (Synchronous Transport Module level-1) signal and the ODU signal is ODU0 (payload portion 1238.95 Mbps).

[0041] Figure 2 shows an example of mapping an STM-1 signal to an ODU0 frame. An ODU0 frame consists of 4 rows and 3824 columns of bytes. Figure 2 shows the first 24 columns of the ODU0 frame.

[0042] Columns 1 to 14 of the ODU0 signal are ODU OH, where information required for transmission is inserted. Columns 15 and 16 of the ODU0 signal are OPU OH, where information related to the client signal in the payload portion is inserted. Columns 17 to 3824 of the ODU0 signal are payload, where the client signal is inserted.

[0043] When a 155.52 Mbps STM-1 signal is mapped to an ODU0 signal with a 1238.95 Mbps payload, the ratio of the former to the latter is 155.52 ÷ 1238.95 ≒ 1 / 8. Therefore, a client signal (STM-1 signal) is inserted into one byte of the eight bytes of the ODU0 payload, and stuff bytes are inserted into the remaining seven bytes.

[0044] 2 shows an example in which stuff bytes are inserted into seven bytes in columns 17 to 23 of the ODU0 signal, and one byte of STM-1 signal is inserted into column 24. Furthermore, stuff bytes are inserted into seven bytes in columns 25 to 31 of the ODU0 signal, and one byte of STM-1 signal is inserted into column 32, and from then on, up to column 3824, seven stuff bytes and one byte of STM-1 signal are alternately mapped.

[0045] In the example shown in Figure 2, the 1238.95 Mbps payload of the ODU0 signal, which is the difference between the 155.52 Mbps bit rate of the STM-1 signal and the 1083.43 Mbps payload, is stuff bytes. If stuff bytes account for 87% of the bit rate, the utilization efficiency of the ODU0 transmission band will be very poor.

[0046] <Embodiment> Next, preferred embodiments of the present disclosure will be described with reference to the drawings.

[0047] 3 is a block diagram showing an example of the configuration of an embodiment of an OTN transmission / reception system 100. The OTN transmission / reception system 100 includes an OTN transmitter 300 that receives a client signal and transmits an OTN signal, and an OTN receiver 400 that is connected to the OTN transmitter 300 via a transmission path, receives the OTN signal, and transmits the client signal.

[0048] 3 shows an example in which a client signal transmitted by a client transmitting device 1 is transmitted by an OTN transmitting device 300 and an OTN receiving device 400 and is received by a client receiving device 2. Also, FIG. 3 shows an example in which a second client signal transmitted by a second client transmitting device 11 is transmitted by an OTN transmitting device 300 and an OTN receiving device 400 and is received by a second client receiving device 12.

[0049] 3 simply indicates the direction of signal (data) flow, but does not exclude bidirectionality. This also applies to other block diagrams.

[0050] The OTN transmitting device 300 shown in FIG. 3 includes a client signal receiving unit 31, a second client signal receiving unit 301, an encapsulation unit 302, an ODU clock generating unit 32, a mapping control unit 33, an OPU OH generating unit 34, a transmission selecting unit 35, and an ODU frame generating unit 36.

[0051] The second client signal receiving unit 301 has a function of receiving the second client signal transmitted by the second client transmitting device 11 and buffering the data of the second client signal (hereinafter also referred to as second client data). The second client signal receiving unit 301 also has a function of outputting the buffered second client data to the encapsulating unit 302 based on the selection signal output by the mapping control unit 33.

[0052] The encapsulation unit 302 has a function of encapsulating the second client data output by the second client signal receiving unit 301. The encapsulation unit 302 outputs the encapsulated second client data to the transmission selector .

[0053] In this embodiment, the bandwidth of the second client data is adjusted according to the difference between the bandwidth of the ODU signal and the bandwidth of the client signal (hereinafter also referred to as stuff byte bandwidth). As an encapsulation method for adjusting the bandwidth of the second client data, various methods can be applied. For example, ITU-T G.7041 GFP-F (Frame mapped GFP (Generic Framing Procedure)) may be applied as an encapsulation method for adjusting the bandwidth of the second client data.

[0054] The encapsulation unit 302 adjusts the bandwidth of the second client data to match the stuff byte bandwidth. The method of bandwidth adjustment is determined by the encapsulation method. For example, when ITU-T G.7041 GFP-F is applied, the encapsulation unit 302 can adjust the bandwidth of the second client data by inserting a GFP idle.

[0055] The mapping control unit 33 of this embodiment has the function of determining the number of bytes of client data and generating a selection signal, similar to the mapping control unit 33 shown in Fig. 1. However, in this embodiment, the mapping control unit 33 outputs the generated selection signal to the second client signal receiving unit 301 and the transmission selection unit 35. Also, in this embodiment, second client data is inserted instead of stuff bytes (00h). Therefore, the selection signal is a signal that indicates whether the signal to be inserted into the OPU data is client data or second client data.

[0056] The transmission selector 35 of this embodiment has a function of selecting either the client data output by the client signal receiver 31 or the second client data encapsulated by the encapsulator 302, based on a selection signal generated by the mapping controller 33. The transmission selector 35 outputs the selected data to the ODU frame generator 36 as OPU data.

[0057] The operations of the client signal receiving unit 31, the ODU clock generating unit 32, the OPU OH generating unit 34, and the ODU frame generating unit 36 ​​of the OTN transmitting device 300 shown in FIG. 3 are the same as the operations of the client signal receiving unit 31, the ODU clock generating unit 32, the OPU OH generating unit 34, and the ODU frame generating unit 36 ​​of the general OTN transmitting device 3 shown in FIG. 1.

[0058] The OTN receiving device 400 shown in Figure 3 includes a demapping control unit 43, an OPU OH processing unit 44, a receiving selection unit 45, an ODU frame processing unit 46, a client signal transmitting unit 41, a decapsulation unit 402, a second client signal transmitting unit 401, and a second client clock generating unit 403.

[0059] The selector for reception 45 of this embodiment has a function of extracting client data and encapsulated second client data from OPU data based on a selection signal generated by the demapping controller 43. In this embodiment, the selector for reception 45 outputs the client data to the client signal transmitter 41 and outputs the encapsulated second client data to the decapsulator 402.

[0060] The decapsulating unit 402 has a function of decapsulating the encapsulated second client data using a method corresponding to the encapsulation method used by the encapsulating unit 302 of the OTN transmitting device 300. The decapsulating unit 402 outputs the decapsulated second client data to the second client signal transmitting unit 401.

[0061] The second client signal transmitting unit 401 has a function of generating (regenerating) a second client signal based on the second client data decapsulated by the decapsulating unit 402 and the second client clock generated by the second client clock generating unit 403. The second client signal transmitting unit 401 transmits the generated (regenerated) second client signal to the second client receiving device 12.

[0062] The second client clock generating unit 403 has a function of generating a second client clock corresponding to the second client signal. The clock generated by the second client clock generating unit 403 may be generated from a clock signal from a fixed oscillator, or may be generated from a clock generated by the demapping control unit 43 or the decapsulating unit 402.

[0063] The operations of the demapping control unit 43, the OPU OH processing unit 44, the ODU frame processing unit 46, and the client signal transmitting unit 41 of the OTN receiving device 400 shown in FIG. 3 are the same as the operations of the demapping control unit 43, the OPU OH processing unit 44, the ODU frame processing unit 46, and the client signal transmitting unit 41 of the general OTN receiving device 4 shown in FIG. 1.

[0064] As described above, the general OTN transmitting device 3 shown in Fig. 1 is configured to insert a stuff byte (00h) into OPU data, and the general OTN receiving device 4 shown in Fig. 1 is configured to discard the stuff byte (00h) inserted into the OPU data.

[0065] In contrast, the OTN transmission / reception system 100 of this embodiment includes an OTN transmission device 300 and an OTN reception device 400 instead of the OTN transmission device 3 and OTN reception device 4 shown in Fig. 1. The OTN transmission device 300 is configured to insert a second client signal transmitted from the second client transmission device 11 into the OPU data instead of a stuff byte (00h). The OTN reception device 400 is configured to extract the second client signal inserted into the OPU data and transmit it to the second client reception device 12.

[0066] Next, a description will be given of the processing operations of the OTN transmitting and receiving system 100. Note that a description of the same processing operations as those of the general OTN transmitting and receiving system shown in Fig. 1 will be omitted, and the processing operations unique to the OTN transmitting and receiving system 100 will be mainly described.

[0067] FIG. 4 is a flowchart showing the processing operation of the OTN transmitter 300 in the OTN transceiver system 100.

[0068] When the client signal receiving unit 31 of the OTN transmission device 300 receives the client signal transmitted by the client transmission device 1, it extracts client data and a client clock from the client signal (step S11). Then, the client signal receiving unit 31 outputs the client data to the transmission selector 35 and outputs the client clock to the mapping control unit 33.

[0069] Next, the mapping control unit 33 determines the number of bytes of client data to be inserted into the ODU frame based on the difference in frequency between the client clock extracted by the client signal receiving unit 31 and the ODU clock generated by the ODU clock generating unit 32. Furthermore, the mapping control unit 33 generates a selection signal based on the determined number of bytes of client data (step S12).

[0070] When the second client signal receiving unit 301 of the OTN transmission device 300 receives the second client signal transmitted by the second client transmission device 11, it buffers the data of the second client signal (second client data) (step S13). Note that the process of step S13 may be executed in parallel with steps S11 and S12, starting from before the process of steps S11 and S12.

[0071] Next, the second client signal receiving unit 301 outputs the buffered second client data to the encapsulating unit 302 based on the selection signal generated by the mapping control unit 33. Note that if the buffer of the second client receiving unit 301 overflows, the second client signal receiving unit 301 discards the second client data.

[0072] Next, the encapsulation unit 302 encapsulates the second client data output by the second client signal receiving unit (step S14), and outputs the encapsulated second client data to the transmission selector 35.

[0073] Next, the transmission selection unit 35 selects either the client data or the encapsulated second client data based on the selection signal generated by the mapping control unit 33, and outputs it to the ODU frame generation unit 36 ​​as OPU data (step S15).

[0074] Next, the ODU frame generation unit 36 ​​generates an ODU frame by inserting the OPU OH output by the OPU OH generation unit 34 into the OPU data output by the transmission selection unit 35 (step S16).The ODU frame generation unit 36 ​​then transmits the generated ODU frame to the OTN receiving device 400 (step S17).

[0075] FIG. 5 is a flowchart showing the processing operation of the OTN receiver 400 in the OTN transmitter-receiver system 100. As shown in FIG.

[0076] When the ODU frame processing unit 46 of the OTN receiving device 400 receives the ODU frame transmitted by the OTN transmitting device 300, it extracts the OPU data, the ODU clock, and the OPU OH from the received ODU frame (step S21). Then, the ODU frame processing unit 46 outputs the OPU data to the receiving selector 45. In addition, the ODU frame processing unit 46 outputs the ODU clock to the demapping control unit 43. In addition, the ODU frame processing unit 46 outputs the OPU OH to the OPU OH processing unit 44.

[0077] Next, the OPU OH processing unit 44 identifies the number of bytes of the client data in the ODU frame based on the OPU OH (step S22). Then, the OPU OH processing unit 44 outputs the identified number of bytes of the client data to the demapping control unit 43.

[0078] Next, the demapping control unit 43 generates a selection signal and a client clock based on the ODU clock and the number of bytes of the client data (step S23). Then, the demapping control unit 43 outputs the generated selection signal to the reception selection unit 45. In addition, the demapping control unit 43 outputs the generated client clock to the client signal transmission unit 41.

[0079] Next, the selector for reception 45 extracts the client data and the encapsulated second client data from the OPU data based on the selection signal generated by the demapping controller 43 (step S24). Then, the selector for reception 45 outputs the client data to the client signal transmitter 41 and outputs the encapsulated second client data to the decapsulator 402.

[0080] Next, the client signal transmitting unit 41 generates (regenerates) a client signal based on the client data extracted by the receiving selector 45 and the client clock generated by the demapping control unit 43. Then, the client signal transmitting unit 41 transmits the generated (regenerated) client signal to the client receiving device 2 (step S25).

[0081] Furthermore, the decapsulating unit 402 decapsulates the encapsulated second client data using a method corresponding to the encapsulation performed by the encapsulating unit 302 of the OTN transmitting device 300 (step S26). Then, the decapsulating unit 402 outputs the second client data to the second client signal transmitting unit 401.

[0082] Next, the second client signal transmitting unit 401 generates a second client signal based on the second client data decapsulated by the decapsulating unit 402 and the second client clock generated by the second client clock generating unit 403. Then, the second client signal transmitting unit 401 transmits the generated second client signal to the second client receiving device 12 (step S27). Note that the processes of generating and transmitting the second client signal in steps S26 and S27 may be performed before the process of generating and transmitting the first client signal in step S25.

[0083] In this embodiment, in addition to or instead of the above-described configuration, a configuration can be applied in which information about the second client signal is transmitted via the OPU OH. For example, the OPU OH generation unit 34 of the OTN transmission device 300 inserts information such as the type and clock frequency of the second client into the reserved area of ​​the PSI of the OPU OH. Then, the OPU OH processing unit 44 of the OTN reception device 400 extracts this information from the OPU OH. With this configuration, the OTN reception device 400 can configure the operations of the second client signal transmission unit 401, decapsulation unit 402, and second client clock generation unit 403 based on the extracted information.

[0084] Next, as a specific example of this embodiment, we will explain the operation processing of the OTN transceiver system 100 when the client signal is STM-1 (155.52 Mbps), the ODU signal is ODU0 (payload portion 1238.95 Mbps), and the second client signal is GbE (Gigabit Ethernet) such as 1000BASE-T or 1000BASE-X.

[0085] First, we will explain the operation process of the OTN transmission device 300 in this specific example. The second client signal receiving unit 301 of the OTN transmission device 300 receives the second client signal (GbE signal) transmitted by the second client signal transmitting device 11. The second client signal receiving unit 301 deletes idles from the second client signal (GbE signal) and buffers the packets.

[0086] Next, the second client receiving unit 301 outputs the buffered packets to the encapsulating unit 302 based on the selection signal generated by the mapping control unit 33. Note that the second client receiving unit 301 may perform flow control on the second client transmitting device 11 as necessary.

[0087] Next, the encapsulation unit 302 encapsulates the packet output by the second client receiving unit 301 based on, for example, ITU-T G.7041 GFP-F. The encapsulation unit 302 outputs the encapsulated data to the transmission selecting unit 35. Note that if the buffer of the second client signal receiving unit 301 is empty, the encapsulation unit 302 outputs GFP Idle.

[0088] Next, the transmission selector 35 selects either the client data output by the client signal receiver 31 or the data encapsulated by the encapsulator 302, based on the selection signal generated by the mapping controller 33. The transmission selector 35 outputs the selected data to the ODU frame generator 36.

[0089] Fig. 6 is a diagram showing an image of an ODU frame when a client signal: STM-1 and a second client signal: GbE are mapped to ODU0 in the OTN transmission / reception system 100. Fig. 6 shows an example in which a GbE signal is inserted into 7 bytes from columns 17 to 23 of the ODU0 signal, and one byte of an STM-1 signal is inserted into column 24. Furthermore, a GbE signal is inserted into 7 bytes from columns 25 to 31 of the ODU0 signal, and one byte of an STM-1 signal is inserted into column 32, and from then on up to column 3824, 7 bytes of GbE signals and 1 byte of STM-1 signals are alternately mapped. As shown in Fig. 6, the OTN transmission / reception system 100 can map one byte of the 8 bytes of the ODU0 payload to STM-1 and the remaining 7 bytes to a GbE signal.

[0090] Next, a description will be given of the operation process of the OTN receiver 400 in this specific example. When the OTN receiver 400 receives the ODU frame transmitted by the OTN transmitter 300, the OTN receiver 400 performs the same processes as steps S21 to S23 described above.

[0091] Next, the reception selection unit 45 of the OTN receiving device 400 extracts the client data and the encapsulated data from the OPU data output by the ODU frame processing unit 46, based on the selection signal generated by the demapping control unit 43. The reception selection unit 45 outputs the client data to the client signal transmission unit 41, and outputs the encapsulated data to the decapsulation unit 402.

[0092] Next, the decapsulating unit 402 decapsulates, based on ITU-T G.7041 GFP-F, the encapsulated data output by the receiving selector 45. The decapsulating unit 402 extracts packets and outputs them to the second client signal transmitting unit 401.

[0093] The second client signal transmitting unit 401 transmits the packet output by the decapsulating unit 402 to the second client receiving device 12 as a GbE signal based on the clock generated by the second client clock generating unit 403 .

[0094] In this way, in this embodiment, the second client signal can be transmitted from the second client transmitting device 11 to the second client receiving device 12 by utilizing the band that was used to transmit stuff bytes in a typical OTN transmitting / receiving system.

[0095] As described above, in a typical OTN transmission / reception system, when mapping an STM-1 signal to ODU0, the STM-1 signal is mapped to one byte of the eight bytes of the ODU0 payload. Furthermore, in a typical OTN transmission / reception system, a stuff byte (00h) is inserted into the remaining seven bytes of the ODU0 payload. In a typical OTN transmission / reception system, the stuff byte (00h) is discarded on the receiving side, resulting in poor utilization of the transmission bandwidth.

[0096] In contrast, in this embodiment, it is possible to map a second client signal (GbE signal) to the remaining 7 bytes of the ODU0 payload. With this configuration, this embodiment can improve the utilization efficiency of the transmission band. That is, in this embodiment, when mapping is performed according to GMP in ITU-T G.709 OTN, other client signals are inserted into stuff bytes where invalid data (00h) is normally inserted, thereby enabling transmission that makes efficient use of the band.

[0097] Furthermore, this embodiment is configured to encapsulate and insert the second client signal. With this configuration, this embodiment makes it possible to insert variable-length data such as the main signal (i.e., the second client signal).

[0098] Next, another application example of the configuration of the present disclosure will be described. The configuration of the present disclosure can be applied to a 5G (5th Generation) base station device, and can multiplex a C / U-Plane that transmits and receives control signals and user data and an M-Plane that transmits and receives maintenance monitoring signals.

[0099] 7 is a block diagram showing an example in which the configuration of the present disclosure is applied to a 5G base station device. In the application example shown in Fig. 7, a DU (Distributed Unit) device (transmission) 500 and an RU (Radio Unit) device (reception) 600 are connected by a 25 Gbps ODU signal: ODU25.

[0100] The DU device (transmitting) 500 includes a C / U-Plane transmitting unit 501, an M-Plane transmitting unit 511, an ODUflex mapping unit 531, a second client signal receiving unit 301, an encapsulation unit 302, an ODU25 clock generating unit 532, a mapping control unit 33, an OPU OH generating unit 34, a transmission selecting unit 35, and an ODU25 frame generating unit 536.

[0101] The RU device (receiving) 600 includes a demapping control unit 43, an OPU OH processing unit 44, a receiving selection unit 45, an ODU frame 25 processing unit 646, an ODUflex demapping unit 641, a decapsulation unit 402, a second client signal transmitting unit 401, a second client clock generating unit 403, a C / U-Plane receiving unit 602, and an M-Plane receiving unit 612.

[0102] In addition, in the application example shown in Figure 7, a client signal, C / U-Plane (25GBASE-R), is transmitted from the C / U-Plane transmitter 501 in the DU device (transmitting) 500 to the C / U-Plane receiver 601 in the RU device (receiving).

[0103] The C / U-Plane (25GBASE-R) is mapped to ITU-T G.709 ODUflex in the DU device (transmitting) 500 based on BMP (Bit-synchronous Mapping Procedure), and then mapped to ODU25 based on GMP (Generic Mapping Procedure).

[0104] In addition, in the application example shown in Figure 7, the M-Plane, which is a second client signal, is transmitted from the M-Plane transmission unit 511 in the DU device (transmission) 500 to the C / U-Plane reception unit 611 in the RU device (reception).

[0105] When 25GBASE-R is mapped to ODUflex, the bit rate is 25,890 Mbps. The bit rate of the ODU25 payload is 26,299 Mbps. This means that there is approximately 400 Mbps free space in the ODU25 payload bandwidth.

[0106] In a typical transmission method, stuff bytes (00h) are transmitted in this free band, but by applying the configuration of this disclosure, it is possible to transmit low-speed signals such as M-Plane. Note that when transmitting from an RU device to a DU device, the configuration is similar to the application example shown in Figure 7.

[0107] Next, a specific transmission method of the application example shown in Fig. 7 will be described. An ODUflex mapping unit 531 in the DU device (transmission) 500 maps the C / U-Plane sent from the C / U-Plane transmission unit 501 to an ODUflex of ITU-G.709.

[0108] The ODU25 clock generating unit 532 generates an ODU clock of ODU25. Then, the ODU25 clock generating unit 532 outputs the generated ODU clock of ODU25 to the mapping control unit 33 and the ODU25 frame generating unit 536.

[0109] Based on the selection signal generated by the mapping control unit 33, the transmission selection unit 35 selects either the client data output by the ODUflex mapping unit 531 or the M-Plane encapsulated by the encapsulation unit 302, and outputs it to the ODU25 frame generation unit 536 as OPU data.

[0110] The ODU25 frame generator 536 generates an ODU25 based on the OPU data output by the transmission selector 35 and the OPU OH generated by the OPU OH generator 34. Then, the ODU25 frame generator 536 transmits the generated ODU25 to the RU device (reception) 600.

[0111] The operations of the second client signal receiving unit 301, the encapsulation unit 302, the mapping control unit 33, and the OPU OH generation unit 34 in the DU device (transmission) 500 are similar to the operations of the second client signal receiving unit 301, the encapsulation unit 302, the mapping control unit 33, and the OPU OH generation unit 34 of the OTN transmission device 300 shown in Figure 3.

[0112] In RU device (receiving) 600, ODU25 frame processing section 646 extracts OPU data, OPU OH, and ODU clock from the received ODU25.

[0113] The ODUflex demapping unit 641 demaps the C / U-Plane from the ODUflex of ITU-T G.709 and sends it to the C / U-Plane receiving unit 602 .

[0114] The operations of the OPU OH processing unit 44, demapping control unit 43, reception selection unit 45, decapsulation unit 402, second client signal transmission unit 401, and second client clock generation unit 403 in the RU device (reception) 600 are similar to the operations of the OPU OH processing unit 44, demapping control unit 43, reception selection unit 45, decapsulation unit 402, second client signal transmission unit 401, and second client clock generation unit 403 in the OTN reception device 400 shown in Fig. 3. Also, the operation of the M-Plane reception unit 612 is similar to that of the second client reception device 12 shown in Fig. 3.

[0115] Next, an overview of the present disclosure will be described. Fig. 8 is a block diagram showing an overview of a transmission device according to the present disclosure. A transmission device 3000 (implemented by an OTN transmission device 300 in the embodiment) shown in Fig. 8 includes mapping means 3001 (implemented by a mapping control unit 33 and a transmission selector 35 in the embodiment) that maps a first client signal (corresponding to an STM-1 signal in the embodiment) to an ODU payload area by GMP, and maps a second client signal (corresponding to a GbE signal in the embodiment) different from the first client signal to another area of ​​the ODU payload area.

[0116] 9 is a block diagram showing an outline of a receiving device according to the present disclosure. The receiving device 4000 shown in Fig. 9 (implemented by the OTN receiving device 400 in the embodiment) includes a demapping means 4001 (implemented by the demapping control unit 43 and the receiving selector 45 in the embodiment) that extracts a first client signal and a second client signal from an ODU signal (corresponding to the ODU signal in which an STM-1 signal and a GbE signal are mapped as shown in Fig. 6) in which a first client signal is mapped to an ODU payload area by GMP and a second client signal different from the first client signal is mapped to another area of ​​the ODU payload area.

[0117] A part or all of the above-described embodiments can be described as, but not limited to, the following supplementary notes.

[0118] (Appendix 1) A transmitting device that uses OTN, characterized in that it comprises a mapping means that maps a first client signal to an ODU payload area using GMP and maps a second client signal different from the first client signal to another area of ​​the ODU payload area.

[0119] (Appendix 2) 2. The transmitting device according to claim 1, further comprising: an encapsulation means for encapsulating the second client signal, wherein the mapping means maps the first client signal to the ODU payload area using the GMP, and maps the second client signal encapsulated by the encapsulation means to another area of ​​the ODU payload area.

[0120] (Appendix 3) 3. The transmitting device according to claim 2, wherein the encapsulating means encapsulates the second client signal based on ITU-T G.7041 GFP-F.

[0121] (Appendix 4) A receiving device that uses OTN, comprising: a demapping means that extracts a first client signal and a second client signal from an ODU signal in which a first client signal is mapped to an ODU payload area by GMP and a second client signal different from the first client signal is mapped to another area of ​​the ODU payload area.

[0122] (Appendix 5) The receiving device according to Supplementary Note 4, further comprising: a decapsulating means for extracting the first client signal and the encapsulated second client signal from an ODU signal in which the first client signal is mapped to the ODU payload area by the GMP and the second client signal encapsulated in another area of ​​the ODU payload area, and for decapsulating the encapsulated second client signal extracted by the demapping means.

[0123] (Appendix 6) 6. The receiving device according to claim 5, wherein the decapsulating means decapsulates the second client signal encapsulated in accordance with ITU-T G.7041 GFP-F in accordance with ITU-T G.7041 GFP-F.

[0124] (Appendix 7) A transmission system comprising a transmitting device according to any one of Supplementary Note 1 to Supplementary Note 3 and a receiving device according to any one of Supplementary Note 4 to Supplementary Note 6.

[0125] (Appendix 8) A transmission method using OTN, characterized in that a first client signal is mapped to an ODU payload area by GMP, and a second client signal different from the first client signal is mapped to another area of ​​the ODU payload area.

[0126] (Appendix 9) 2. The transmission method according to claim 1, further comprising: encapsulating the second client signal; mapping the first client signal to the ODU payload area using the GMP; and mapping the encapsulated second client signal to another area of ​​the ODU payload area.

[0127] (Appendix 10) 10. The transmission method of claim 9, wherein the second client signal is encapsulated according to ITU-T G.7041 GFP-F.

[0128] (Appendix 11) A receiving method using OTN, characterized in that a first client signal and a second client signal are extracted from an ODU signal in which a first client signal is mapped to an ODU payload area by GMP and a second client signal different from the first client signal is mapped to another area of ​​the ODU payload area.

[0129] (Appendix 12) 12. The receiving method according to claim 11, wherein the first client signal is mapped to the ODU payload area by the GMP and the second client signal encapsulated in another area of ​​the ODU payload area is mapped, and the first client signal and the encapsulated second client signal are extracted from the ODU signal, and the extracted encapsulated second client signal is decapsulated.

[0130] (Appendix 13) 13. The receiving method according to claim 12, wherein the second client signal encapsulated in accordance with ITU-T G.7041 GFP-F is decapsulated in accordance with ITU-T G.7041 GFP-F. [Industrial Applicability]

[0131] The present disclosure is suitably applied to transmission devices and systems that perform optical transmission. [Explanation of symbols]

[0132] 1. Client transmitter 2. Client receiving device 3,300 OTN transmission equipment 4,400 OTN receivers 11 Second client transmitter 12 Second client receiving device 31 Client signal receiver 32 ODU clock generation unit 33 Mapping control section 34 OPU OH generation section 35 Transmission selection section 36 ODU frame generator 301 Second client signal receiving unit 302 Encapsulation Department 41 Client signal transmitter 43 Demapping control section 44 OPU OH processing unit 45 Receiving selection section 46 ODU frame processing section 401 Second client signal transmitting unit 402 Decapsulator 403 Second client clock generation unit 100 OTN transmission and reception system 500 DU device (transmitting) 501 C / U-Plane transmitter 511 M-Plane transmitter 531 ODUflex Mapping Section 532 ODU25 clock generation unit 536 ODU25 frame generator 600 RU device (receiving) 602 C / U-Plane receiver 612 M-Plane receiver 641 ODUflex Demapping Unit 646 ODU frame 25 processing section 3000 Transmitting Device 3001 Mapping Method 4000 receiving device 4001 Demapping means

Claims

1. A transmitting device using OTN, The present invention includes a mapping unit that maps a first client signal to an ODU payload area by GMP, and maps a second client signal different from the first client signal, instead of stuff bytes, to an area of ​​the ODU payload area where the first client signal is not mapped. A transmitting device characterized by:

2. An encapsulation means for encapsulating the second client signal based on a difference between a bandwidth of an ODU signal and a bandwidth of the first client signal, The mapping means maps the first client signal to the ODU payload area according to the GMP, and maps the second client signal encapsulated by the encapsulation means to an area of ​​the ODU payload area to which the first client signal is not mapped, in place of stuff bytes.

2. The transmitting device according to claim 1.

3. The encapsulation means encapsulates the second client signal based on ITU-T G. 7041 GFP-F.

3. The transmitting device according to claim 2.

4. A receiving device that uses OTN, The ODU signal is provided with a demapping means for extracting the first client signal and the second client signal from an ODU signal in which a first client signal is mapped to an ODU payload area by GMP and a second client signal different from the first client signal is mapped in place of stuff bytes in an area of ​​the ODU payload area where the first client signal is not mapped. A receiving device characterized by:

5. the demapping means extracts the first client signal and the encapsulated second client signal from an ODU signal in which the first client signal is mapped to the ODU payload area by the GMP and the second client signal is encapsulated based on a difference between a bandwidth of the ODU signal and a bandwidth of the first client signal and mapped in place of stuff bytes to an area of ​​the ODU payload area in which the first client signal is not mapped, The second client signal is extracted by the de-mapping means.

5. The receiving device according to claim 4.

6. The decapsulating means decapsulates the second client signal encapsulated based on ITU-T G. 7041 GFP-F based on ITU-T G. 7041 GFP-F.

6. The receiving device according to claim 5.

7. A transmitting device according to any one of claims 1 to 3; The receiving device according to any one of claims 4 to 6 is provided. A transmission system characterized in that:

8. A transmission method using OTN, A first client signal is mapped to an ODU payload area by GMP, and a second client signal different from the first client signal is mapped to an area of ​​the ODU payload area where the first client signal is not mapped, instead of stuff bytes. A transmission method comprising:

9. A receiving method using OTN, A first client signal is mapped to an ODU payload area by GMP, and a second client signal different from the first client signal is mapped in place of stuff bytes in an area of ​​the ODU payload area where the first client signal is not mapped, and the first client signal and the second client signal are extracted from the ODU signal. A receiving method characterized by:

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