Client signal mapping and de-mapping method and related equipment

Abstract

The invention provides a client signal mapping method, a client signal demapping method and related equipment, which are applied to the field of communication. The client signal mapping method comprises the following steps that a source end device obtains a client signal and maps the client signal to a first data frame, the first data frame comprises a first data block and a second data block, the second data block is the next data block adjacent to the first data block, and the first data block is the next data block adjacent to the second data block; the second data block carries the data verification overhead of the first data block; and the source end equipment maps the first data frame to the second data frame and sends the second data frame. According to the technical scheme, multi-path lossless protection can be realized, and the network reliability is improved.

Description

Technical Field

[0001] This application relates to the field of communications, and in particular, to a method for mapping and demapping customer signals and related devices. Background Art

[0002] With the development of optical transmission technology, the optical transport network (OTN) has gradually replaced the synchronous digital hierarchy (SDH) as the bearer network of the Ethernet network. As SDH devices are gradually phased out, small-grain OTN with a 10M granularity is added on the basis of the existing large-grain OTN to realize the migration of small-grain services from the SDH network to the OTN network. This small-grain OTN technology is defined as fine grain optical transport network (fgOTN). FgOTN inherits the characteristics of traditional large-grain OTN and SDH physical hard pipes and hard isolation. In addition, during the process of mapping and multiplexing customer-side services to fgODUflex, fgOTN technology retains the clock information of customer-side services, which can be used to recover the customer-side service clock at the receiving end to achieve clock transparent transmission. Therefore, full-network clock synchronization is no longer required.

[0003] The traditional protection method for OTN is subnetwork connection protection (SNCP) protection. In this solution, services are lossy during protection switching. However, in industry application scenarios such as the power production network, the reliability requirements for the bearer network are extremely high. Lossy protection switching such as SNCP does not meet the reliability requirements, and a solution that supports multi-path lossless protection needs to be proposed to improve network reliability. Summary of the Invention

[0004] This application provides a method for transmitting customer signals and related devices. By inserting the data check overhead of the current data block into the next data block, service lossless protection can be achieved and the reliability of the service can be improved.

[0005] In a first aspect, this application provides a method for mapping customer signals. This method can be executed by a source device, and the source device can be an OTN device. The method includes: The source device obtains a customer signal and maps the customer signal to a first data frame, where the first data frame includes a first data block and a second data block, the second data block is the next data block adjacent to the first data block, and the second data block carries the data check overhead of the first data block. The source device maps the first data frame to a second data frame and sends the second data frame.

[0006] The technical solution provided by this application can carry the data verification overhead of the first data block in the second data block, achieving lossless service protection and improving the reliability of the service.

[0007] In a possible implementation, the data verification overhead is located in the overhead area or the payload area of the second data block. The data verification overhead of the first data block can be carried in the reserved bytes in the overhead area of the second data block, or in any byte in the payload area of the second data block. For example, it can be carried in the first two bytes at the start of the payload area of the second data block.

[0008] In a possible implementation, the first data frame includes multiple 1904-byte data blocks and multiple 1920-byte data blocks, and the 1904-byte data blocks and the 1920-byte data blocks are alternately distributed. Dividing the first data frame into multiple data blocks is conducive to achieving lossless service protection.

[0009] In a possible implementation, the data verification overhead is any one or more of cyclic redundancy CRC verification overhead, bit-interleaved parity BIP verification overhead, frame check sequence FCS verification overhead, etc.

[0010] In a possible implementation, the first data frame is a small-granularity flexible optical data unit fgODUflex frame.

[0011] In a second aspect, this application provides a method for demapping a client signal. This method can be executed by a downstream device (an intermediate device or a sink device), and the downstream device can be an OTN device. The method includes: The downstream device receives a second data frame and demaps the second data frame to obtain a first data frame, where the first data frame includes a first data block and a second data block, the second data block is the next data block adjacent to the first data block, and the second data block carries the data verification overhead of the first data block. The downstream device demaps the first data frame to obtain the client signal.

[0012] The technical solution provided by this application can carry the data verification overhead of the first data block in the second data block, achieving lossless service protection and improving the reliability of the service.

[0013] In a possible implementation, the data verification overhead is located in the overhead area or the payload area of the second data block. The data verification overhead of the first data block can be carried in the reserved bytes in the overhead area of the second data block, or in any byte in the payload area of the second data block. For example, it can be carried in the first two bytes at the start of the payload area of the second data block.

[0014] In a possible implementation, the first data frame includes a plurality of data blocks of 1904 bytes and a plurality of data blocks of 1920 bytes, and the data blocks of 1904 bytes and the data blocks of 1920 bytes are alternately distributed. Dividing the first data frame into multiple data blocks is beneficial to realizing lossless service protection.

[0015] In a possible implementation, the data check overhead is any one or more of cyclic redundancy CRC check overhead, bit-interleaved parity BIP check overhead, frame check sequence FCS check overhead, etc.

[0016] In a possible implementation, the first data frame is transmitted through a working path or a protection path, and the data check overhead is used to instruct the downstream device to select the first data frame corresponding to the working path or the protection path to obtain the client signal. By using the data check overhead to indicate whether the downstream device performs path switching, lossless service protection is realized.

[0017] In a possible implementation, the working path and the protection path include different clock sources, and the data check overhead is used to instruct the downstream device to select the clock source of the working path or the protection path. When path switching is required, by using the data check overhead to instruct the downstream device to select the corresponding path clock source, the client signal can be restored more accurately.

[0018] In a possible implementation, the first data frame is a small-granularity flexible optical data unit fgODUflex frame.

[0019] In a third aspect, the present application provides a sending device, which may be the source device described in the first aspect. The sending device includes: an acquisition module for acquiring a client signal; a mapping module for mapping the client signal to a first data frame, where the first data frame includes a first data block and a second data block, the second data block is the next data block adjacent to the first data block, and the data check overhead of the first data block is carried in the second data block; the mapping module is further configured to map the first data frame to the second data frame; and a sending module for sending the second data frame.

[0020] The beneficial effects in the third aspect or any possible implementation manner in the third aspect may be referred to the beneficial effects described in the first aspect or any possible implementation manner in the first aspect.

[0021] In a possible implementation, the data check overhead is located in the overhead area or the payload area of the second data block.

[0022] In a possible implementation, the first data frame includes a plurality of data blocks of 1904 bytes and a plurality of data blocks of 1920 bytes, and the data blocks of 1904 bytes and the data blocks of 1920 bytes are alternately distributed.

[0023] In a possible implementation, the data verification overhead is any one or more of cyclic redundancy CRC verification overhead, bit-interleaved parity BIP verification overhead, frame check sequence FCS verification overhead, etc.

[0024] In a possible implementation, the first data frame is a small-granularity flexible optical data unit fgODUflex frame.

[0025] In a fourth aspect, the present application provides a receiving device, which may be the downstream device described in the second aspect. The receiving device includes: a receiving module for receiving a second data frame; a demapping module for demapping the second data frame to obtain a first data frame, where the first data frame includes a first data block and a second data block, the second data block is the next data block adjacent to the first data block, and the data verification overhead of the first data block is carried in the second data block; the demapping module is further configured to demap the first data frame to obtain a client signal.

[0026] The beneficial effects in the fourth aspect or any possible implementation manner in the fourth aspect may be referred to the description of the beneficial effects in the second aspect or any possible implementation manner in the second aspect.

[0027] In a possible implementation, the data verification overhead is located in the overhead area or the payload area of the second data block.

[0028] In a possible implementation, the first data frame includes a plurality of data blocks of 1904 bytes and a plurality of data blocks of 1920 bytes, and the data blocks of 1904 bytes and the data blocks of 1920 bytes are alternately distributed.

[0029] In a possible implementation, the data verification overhead is any one or more of cyclic redundancy CRC verification overhead, bit-interleaved parity BIP verification overhead, frame check sequence FCS verification overhead, etc.

[0030] In a possible implementation, the first data frame is transmitted through a working path or a protection path, and the data verification overhead is used to instruct the downstream device to select the client signal from the first data frame corresponding to the working path or the protection path.

[0031] In a possible implementation, the working path and the protection path include different clock sources, and the data verification overhead is used to instruct the downstream device to select the clock source of the working path or the protection path.

[0032] In one possible implementation, the first data frame is a small-granularity flexible optical data unit fgODUflex frame.

[0033] In a fifth aspect, the present application provides a communication system, characterized in that the communication system includes a sending device as described in the third aspect or any one of the possible implementation manners in the third aspect, and a receiving device as described in the fourth aspect or any one of the possible implementation manners in the fourth aspect.

[0034] In a sixth aspect, the present application provides a data frame, which includes a first data block and a second data block. The second data block is the next adjacent data block of the first data block, and the data check overhead of the first data block is carried in the second data block.

[0035] In a seventh aspect, the present application provides a computer storage medium. Instructions are stored in the computer storage medium, and when the instructions are executed on a computer, the computer is caused to execute the method as described in the first aspect or any one of the implementation manners in the first aspect; or the computer is caused to execute the method as described in the second aspect or any one of the implementation manners in the second aspect.

[0036] In an eighth aspect, the present application provides a computer program product. When the computer program product is executed on a computer, the computer is caused to execute the method as described in the first aspect or any one of the implementation manners in the first aspect; or the computer is caused to execute the method as described in the second aspect or any one of the implementation manners in the second aspect. Description of the Drawings

[0037] Figure 1 It is a schematic structural diagram of an OTN;

[0038] Figure 2 It is a schematic structural diagram of an OTN device;

[0039] Figure 3 It is a schematic service mapping diagram of a fgODUflex;

[0040] Figure 4 It is a schematic frame format diagram of a fgODUflex;

[0041] Figure 5 It is a schematic diagram of a data block partitioning method for a fgODUflex frame structure provided by an embodiment of the present application;

[0042] Figure 6 It is a flowchart of a method for customer signal mapping and demapping provided by an embodiment of the present application;

[0043] Figure 7Schematic structural diagram of a communication system provided by an embodiment of the present application;

[0044] Figure 8 Schematic structural diagram of a sending device provided by an embodiment of the present application;

[0045] Figure 9 Schematic structural diagram of a receiving device provided by an embodiment of the present application;

[0046] Figure 10 Schematic structural diagram of a communication device provided by an embodiment of the present application. Detailed implementation manners

[0047] Embodiments of the present application are applicable to optical networks such as optical transport networks or metro transport networks. The optical transport network includes OTN or flexible ethernet (FlexE). In the subsequent description of the present application, OTN will be taken as an example for description. An OTN usually consists of multiple OTN devices connected by optical fibers and can be configured into different topological types such as linear, ring, and mesh according to specific needs. Figure 1 Schematic structural diagram of an OTN. As Figure 1 shown, the OTN includes a source device 101, a sink device 102, and an intermediate subnet 103. Among them, the source device 101 and the sink device 102 are respectively connected to the client devices 1 and 2. The client devices 1 and 2 can be relay protection devices of a power production network, generating E1 services or 2M optical services. The source device 101 maps the client signal generated by the client device 1 into an OTN signal. The OTN signal is transmitted through the intermediate subnet 103 and received by the sink device 102. The sink device 102 recovers the client signal from the OTN signal and sends it to the client device 2. The intermediate subnet 103 can be a fgOTN, and the source device 101 and the sink device 102 can be fgOTN devices, providing multiple fgODUflex transmission paths for the client devices, which is equivalent to a dedicated line service.

[0048] According to actual needs, an OTN device may have different functions. Generally, OTN devices are divided into optical layer devices, electrical layer devices, and optical and electrical hybrid devices. Optical layer devices refer to devices that can process optical layer signals, such as optical amplifiers (OAs) and optical add-drop multiplexers (OADMs). An OA is mainly used to amplify optical signals to support longer transmission distances while ensuring specific performance of the optical signals. An OADM is used to perform spatial transformation on optical signals so that they can be output from different output ports (also known as directions). Electrical layer devices refer to devices that can process electrical layer signals, such as devices that can process OTN signals. Optical and electrical hybrid devices refer to devices that have the ability to process both optical layer signals and electrical layer signals. It should be noted that according to specific integration needs, an OTN device can integrate multiple different functions. The technical solution provided in this application is applicable to OTN devices with electrical layer functions in different forms and integration levels.

[0049] It should be noted that the data frame structure used by the optical transmission device in the embodiments of this application can be an OTN frame, which is used to carry various service data and provide rich management and monitoring functions. The OTN frame can be an optical payload unit (OPU), an optical data unit (ODU), an optical transport unit (OTU), a flexible OTN (FlexO) frame, etc. The OPU includes OPUk, OPUCn, and OPUflex, the ODU includes ODUk, ODUCn, and ODUflex, and the OTU includes OTUk and OTUCn. Among them, the OTU frame includes the ODU frame and OTU overhead, and the ODU frame includes the OPU frame and ODU overhead. k represents different rate levels. For example, k = 1 represents 2.5 Gbps, and k = 4 represents 100 Gbps. Cn represents a variable rate, specifically a rate that is an integer multiple of 100 Gbps. Flex represents flexible. It should also be pointed out that with the development of optical transmission network technology, new types of OTN frames may be defined and are also applicable to this application. For example, the OTN frame can also include an fgOTN frame (including fgODUflex and fgOPUflex) or an optical service unit (OSU) frame. In addition, the method disclosed in this application can also be applicable to other optical transmission network frames such as FlexE frames.

[0050] Figure 2 It is a schematic structural diagram of an OTN device. The OTN device 200 can be Figure 1 any one of the OTN devices A - H inFigure 2 As shown in Figure 2 , the OTN device 200 includes tributary boards 201, cross-connect boards 202, line boards 203, optical layer processing single boards (not shown in the figure), and system control and communication single boards 204.

[0051] The tributary boards 201, cross-connect boards 202, and line boards 203 are used to process electrical layer signals. Among them, the tributary board 201 is used to implement the reception and transmission of various client signals, such as SDH services, packet services, Ethernet services, and / or fronthaul services, etc. Further, the tributary board 201 can be divided into a client-side optical transceiver module and a signal processor. Among them, the client-side optical transceiver module can also be called an optical transceiver, which is used to receive and / or transmit service data. The signal processor is used to implement the mapping and demapping processing of service data to data frames. The cross-connect board 202 is used to implement the switching of data frames and complete the switching of one or more types of data frames. The line board 203 mainly implements the processing of line-side data frames. Specifically, the line board 203 can be divided into a line-side optical module and a signal processor. Among them, the line-side optical module can be called an optical transceiver, which is used to receive and / or transmit data frames. The signal processor is used to implement the multiplexing and demultiplexing, or mapping and demapping processing of the line-side data frames. The system control and communication single board 204 is used to implement system control; specifically, it can collect information from different single boards or send control instructions to the corresponding single boards. Unless otherwise specified, the specific components (such as signal processors) can be one or more, and this application does not make any restrictions. It should also be noted that this application does not make any restrictions on the types of single boards included in the device, the functional design, and the number of single boards. It should be noted that in a specific implementation, the above two single boards may also be designed as one single board. In addition, the network device may also include a backup power supply, a fan for heat dissipation, etc.

[0052] It should be understood that Figure 2 this is only an example of the OTN device provided by this application. According to specific needs, the types and numbers of single boards included in the OTN device may be different. For example, the OTN device as a core node does not have a tributary board 201. Another example is that the OTN device as an edge node has multiple tributary boards 201 or does not have an optical cross-connect board 202. Another example is that the OTN device that only supports the electrical layer function may not have an optical layer processing single board.

[0053] According to the previous description, this application describes the method provided in this application by taking OTN as an example. At this time, the data frame can be an fgOTN frame or a multiframe composed of multiple fgOTN frames. The data frame can be an ODU frame or an OPU frame. Hereinafter, the OTN device will be described exemplarily by taking the data frame as an fgOTN frame as an example.

[0054] The fgOTN path layer provides a more efficient bearer path for services smaller than 1G (sub-1Gbit / s) based on traditional OTN. Figure 3 It is a schematic diagram of service mapping for fgODUflex. As Figure 3 shown, the fgODUflex layer is the client layer of the OPUk / flex layer. The client signal is first mapped to fgOPUflex, and PM overhead and TCM overhead are respectively added to fgOPUflex to generate fgODUflex, which is then mapped into one or more time slots of the OPU.

[0055] Figure 4 It is a schematic diagram of the frame format of fgODUflex. As Figure 4 shown, the frame structure of fgODUflex includes 4 rows and 3824 columns. Among them, columns 1-16 and 1905-1920 are the overhead areas, and columns 17-1904 and 1921-3824 are the payload areas. The meanings of the fields included in the overhead area are shown in Table 1. The frame structure of fgODUflex can be divided into 8 half-rows, and the first 16 bytes of each half-row are FAS and other overheads. For example, the first half-row includes 8-byte FAS0, MFAS, RES, and 8-byte other overheads, and the second half-row includes 4-byte FAS1 and 12-byte other overheads.

[0056] Table 1

[0057]

[0058]

[0059] Figure 5 It is a schematic diagram of the data block division method for the fgODUflex frame structure provided by the embodiment of the present application. As Figure 5 shown, the frame structure of fgODUflex is divided into 8 data blocks in units of bytes, namely 4 data blocks of 1904B (bytes) and 4 data blocks of 1920B (bytes), and 1904B and 1920B are alternately distributed. The first data block of 1904B corresponds to the first half-row of the fgODUflex frame structure (columns 1-1904 in row 1), the second data block of 1920B corresponds to the second half-row of the fgODUflex frame structure (columns 1905-3824 in row 1), and so on.

[0060] It should be noted that Figure 5 what is provided is an example of data block division, and data block division can also be performed in units of 66 bits or 257 bits.

[0061] Based on Figure 5For the divided data blocks, in the embodiments of this application, data verification is performed on the data blocks, and the verification result of the current data block (or referred to as data verification overhead) is inserted into the next data block. For example, cyclic redundancy check (CRC) is performed on each data block, and the CRC verification result of the current data block (or referred to as CRC overhead) is inserted into the next data block. CRC can use 16-bit CRC16 or 32-bit CRC32. The CRC overhead of the current data block is inserted into the overhead area or payload area of the next data block. The CRC overhead can be inserted into the reserved (RES) field in the overhead area, or into the idle bytes of other overhead fields. In the embodiments of this application, BIP verification or frame check sequence (FCS) verification can also be performed on the data blocks, and similarly, the BIP verification result (BIP overhead) of the current data block or the verification result of FCS (FCS overhead) can be inserted into the next data block.

[0062] Table 2 shows an example of the insertion position of the CRC overhead provided by the embodiments of this application. As shown in Table 2, the CRC overhead of data block 1 is inserted into columns 1912 and 1918 of row 1 of the current fgODUflex frame (the overhead area of data block 2), the CRC overhead of data block 2 is inserted into columns 11 and 14 of row 2 of the current fgODUflex frame (the overhead area of data block 3),..., the CRC overhead of data block 8 is inserted into columns 11 and 14 of row 1 of the next fgODUflex frame (the overhead area of data block 1 of the next fgODUflex frame).

[0063] Table 2

[0064] Data block number CRC overhead position Data block 1 1 row, columns 1912, 1918 Data block 2 2 rows, columns 11, 14 Data block 3 2 rows, columns 1912, 1918 Data block 4 3 rows, columns 10, 14 Data block 5 3 rows, columns 1912, 1918 Data block 6 4 rows, columns 11, 14 Data block 7 4 rows, columns 1912, 1918 Data block 8 1 row, columns 11, 14

[0065] The CRC overhead can also be inserted into the payload area of the data block. For example, the CRC overhead of data block 1 is inserted into columns 1921 and 1922 of row 1 of the current fgODUflex frame (the payload area of data block 2), and the CRC overhead of data block 2 is inserted into columns 17 and 18 of row 2 of the current fgODUflex frame (the payload area of data block 3). When the CRC overhead is inserted into the payload area of the data block, the customer signal mapping to the payload area of fgODUflex needs to be adapted. For example, when the CRC overhead is inserted into columns 1921 and 1922 of row 1 of the current fgODUflex frame, the mapping start position of the customer signal is column 1923 of row 1 of the current fgODUflex frame. Since the minimum bandwidth of fgODUflex is 10.4M and the bandwidth occupied by the customer signal (such as E1 service) is 2.4M, occupying 2 bytes in the payload area to carry the CRC overhead does not affect the transmission of the customer signal.

[0066] Figure 6 This is a flowchart of a method for client signal mapping and demapping provided by an embodiment of the present application. As Figure 6 shown, this method can be implemented by an OTN device, which includes a source device, an intermediate device, and a sink device. In some cases, the intermediate device may not be included. Figure 7 This is a schematic structural diagram of a communication system provided by an embodiment of the present application. As Figure 7 shown, this communication system includes a source device and a downstream device. The source device performs the following steps S601 and S602, and the downstream device performs the following steps S602 and S603.

[0067] S601: The source device obtains a client signal and maps the client signal to a first data frame. The first data frame includes a first data block and a second data block. The second data block is the next adjacent data block of the first data block, and the second data block carries the data check overhead of the first data block.

[0068] This step can be implemented on the tributary board of the source device. For example, it can be implemented through a framer chip on the tributary board. The client signal can be a packet service, a constant bit rate (CBR) service, or a variable bit rate (VBR) service. The packet service can also be referred to as an Ethernet service, and the CBR service can include synchronous digital hierarchy (SDH) services, E1 services, etc.

[0069] Reference Figure 7, taking the customer signal as an E1 service and the first data frame as fgODUflex as an example for illustration. The source device receives the E1 service from the customer device, maps the E1 service to a virtual container 12 (VC12), then maps the VC12 to a TU12, and the TU12 is further mapped to the fgODUflex. Among them, the mapping from the E1 service to the VC12 can adopt asynchronous mapping according to the plesiochronous digital hierarchy (PDH) or SDH standard, the mapping from the VC12 to the TU12 can adopt synchronous mapping, and the mapping from the TU12 to the fgODUflex can adopt GMP mapping. The clocks of the VC12, TU12, and fgODUflex are the system local clocks, and the clock of the E1 service input from the customer side is an external clock (provided by the customer device). Therefore, the mapping from the E1 service to the VC12 adopts asynchronous mapping. In addition, since the frequencies of the clocks of the VC12 and TU12 are inconsistent with the system local clock, the system local clock is divided in frequency, and the divided clock is used as the clocks of the VC12 and TU12. For example, if the system local clock is 155.52M, the fgODUflex can directly adopt the system local clock, while the VC12 and TU12 adopt the divided clock of 77M. The frame format of the fgODUflex can be 4 rows and 3824 columns as shown in Figure 4 . The minimum bandwidth of the fgODUflex is 10M, and the time required to send one frame is about 12ms. In order to reduce the cache size and delay introduced by downstream data alignment, the fgODUflex can be partitioned into data blocks in the manner shown in Figure 5 . Data verification is performed on each data block, and the data verification overhead of the current data block is inserted into the overhead area or payload area of the next data block. Among them, the data verification overhead is used to indicate the transmission quality of the data block, and based on the data verification overhead, it can be detected whether there are errors such as bit errors and packet losses. The data verification overhead can be any one or more verification methods such as CRC overhead, BIP overhead, and FCS overhead.

[0070] In the embodiments of this application, the first data frame can be partitioned before the customer signal is mapped to the first data frame. It is also possible to partition the first data frame while the customer signal is being mapped to the first data frame, or to partition the first data frame after the customer signal is mapped to the first data frame.

[0071] S602: The source device maps the first data frame to a second data frame and sends the second data frame.

[0072] This step can be implemented on the tributary board of the source device. For example, it can be implemented through the framer chip on the tributary board. Generally speaking, the rate of the second data frame is higher than that of the first data frame. For example, the first data frame can be fgODUflex or fgOPUflex, and the second data frame can be OPUk, OPUflex or OPUCn. The second data frame can also be any one of ODUk, ODUCn, ODUflex, OTUk, OTUCn, and FlexO. Map the fgODUflex to a higher-rate OPU, ODU or OTU, and then send it to the optical fiber line through the optical interface. In the embodiments of the present application, a 1+1 protection method can be adopted to protect services, that is, the E1 service is mapped to two fgODUflexes, and the two fgODUflexes are transmitted through the working path and the protection path respectively. The receiving end can select the path with higher communication quality to receive services according to the status of the working path and the protection path.

[0073] S603: The downstream device receives the second data frame and demaps the second data frame to obtain the first data frame, where the first data frame includes a first data block and a second data block, the second data block is the next data block adjacent to the first data block, and the data check overhead of the first data block is carried in the second data block.

[0074] This step can be implemented on the tributary board of the downstream device. For example, it can be implemented through the framer chip on the tributary board. The downstream device can be an intermediate device or a sink device. When the 1+1 protection method is adopted, the downstream device can receive the second data frame on the working path and the second data frame on the protection path, and demap the two second data frames respectively to obtain two first data frames. The first data frame can be fgODUflex or fgOPUflex, and the second data frame can be OPUk, OPUflex or OPUCn. The second data frame can also be any one of ODUk, ODUCn, ODUflex, OTUk, OTUCn, and FlexO.

[0075] The downstream device configures caches for the working path and the protection path respectively. Both the working path and the protection path can transmit fgODUflex. For example, the cache size configured for the working path is: the delay difference between the working path and the protection path + the first data block + the front part of the second data block. The second data block is the next data block adjacent to the first data block. In some cases, there are multiple protection paths. For example, protection path 1 and protection path 2, and protection path 1 and protection path 2 have different delays. The delay difference between the working path and protection path 1 is D1, and the delay difference between the working path and protection path 2 is D2. The delay difference between the working path and the protection path based on which the cache size is set can be the larger one of D1 and D2. The front part of the second data block can include the bytes carrying the data check overhead of the first data block, and the bytes before the data check overhead of the first data block. The data check overhead can be CRC overhead, BIP overhead, FCS overhead, etc. For example, when the CRC overhead of the first data block is carried in the overhead area of the second data block, such as columns 1912 and 1918 in the first row of the fgODUflex frame, the front part of the second data block can include the partial bytes from column 1905 to column 1918, or include the partial bytes from column 1905 to column 1920 (i.e., the overhead area of the second data block). The cache size configured for the protection path is: the delay difference between the working path and the protection path + the first data block + the front part of the second data block. The delay difference between the working path and the protection path and the front part of the second data block are as described above and will not be elaborated here. The set cache size includes the first data block and the front part of the second data block. When parsing the first data block, the data check overhead of the first data block can be extracted from the second data block to evaluate the transmission quality of the first data block. In addition, considering the larger value of the delay difference between the working path and different protection paths when setting the cache size is beneficial to the alignment of data blocks.

[0076] The downstream device aligns the data blocks in the working path and the protection path according to the multiframe number, and restores the clocks of the working path and the protection path according to the aligned data blocks. The multiframe number can be the MFAS carried in the overhead area of fgODUflex, and its value ranges from 0 to 255. Generally speaking, the delays of the working path and the protection path are different, and delay compensation is required.

[0077] Based on the data check overhead of the first data block carried by the second data block and the first data block, judge the transmission status of the working path and / or the protection path. The judgment of the transmission status of the working path and the protection path can be independent, that is, judge the transmission status of the working path based on the first data block and the data check overhead on the working path, and judge the transmission status of the protection path based on the first data block and the data check overhead on the protection path. The transmission status of the working path and / or the protection path can be judged based on the alarm status:

[0078] Alarm status = Detect Frame Alignment Signal Loss of Frame (Detect FAS_LOF, dFAS_LOF) || Detect Alarm Indication Signal (Detect AIS, dAIS) || Detect Lock (Detect LCK, dLCK) || Detect Out-of-Service Indication (Detect OCI, dOCI) || Detect Cyclic Redundancy Check Error (Detect CRC ERR, dCRC_ERR)

[0079] The alarm status can be one or more of dFAS_LOF, dAIS, dLCK, dOCI, and dCRC_ERR. dCRC_ERR can be obtained by detecting the data check overhead of the first data block carried in the second data block, and dFAS_LOF, dAIS, dLCK, and dOCI can be obtained by detecting the overhead area of the first data block. The downstream device determines the transmission status of the working path according to the alarm status. For example, when one or more of dFAS_LOF, dAIS, dLCK, dOCI, and dCRC_ERR occur in the working path, it is determined that the working path has a fault. The determination of the transmission status of the protection path is similar.

[0080] S604: The downstream device demaps the first data frame to obtain the client signal.

[0081] This step can be implemented by the tributary board of the downstream device. For example, it can be implemented through the framer chip on the tributary board. The first data frame can be fgODUflex. When the 1+1 protection mode is adopted, fgODUflex can be transmitted on both the working path and the protection path. The downstream device determines the transmission status of the working path and / or the protection path according to the alarm status described in S603, and selects the receiving path of the client signal based on the transmission status of the working path and / or the protection path, that is, selects the fgODUflex for obtaining the client signal. When the working path fails and the protection path is normal, select to obtain the client signal from the protection path. When the fault of the working path is restored, the client signal can be obtained from the working path.

[0082] The downstream device recovers the clocks of the working path and the protection path, and also selects a clock source. Both the working path and the protection path can perform clock recovery based on the clock difference accumulation (DAi) field in the fgODUflex overhead area. Clock recovery can be performed first and then the clock source is selected, or the clock source can be selected first and then clock recovery is performed. The path for clock source selection can be the same as the receiving path of the client signal. For example, when the downstream device selects to obtain the client signal from the working path, it selects the clock of the working path; when the downstream device selects to obtain the client signal from the protection path, it selects the clock of the protection path. In some examples, such as when the client signal is a VBR service, the steps of clock switching and clock recovery may not be performed.

[0083] In the embodiments of the present application, since the first data frame is divided into data blocks and the data check overhead of the current data block is carried in the next data block, the transmission status of the working path can be judged based on the data check overhead. When a fault occurs in the working path, the service can be switched to the protection path without loss, improving the reliability of service transmission.

[0084] Figure 8 It is a schematic structural diagram of the sending device provided by the embodiments of the present application. As Figure 8 shown, the sending device 800 includes an obtaining module 801, a mapping module 802, and a sending module 803. The obtaining module 801 is used to obtain a client signal. The mapping module 802 is used to map the client signal to a first data frame, where the first data frame includes a first data block and a second data block, the second data block is the next data block adjacent to the first data block, and the second data block carries the data check overhead of the first data block. The mapping module is also used to map the first data frame to a second data frame. The sending module 803 is used to send the second data frame. It should be understood that the implementation manner of the sending device 800 can refer to the execution steps of the source device as shown in Figure 6 、 7 shown.

[0085] Figure 9 It is a schematic structural diagram of the sending device provided by the embodiments of the present application. As Figure 9 shown, the receiving device 900 includes a receiving module 901 and a demapping module 902. The receiving module 901 is used to receive the second data frame. The demapping module 902 is used to demap the second data frame to obtain the first data frame, where the first data frame includes a first data block and a second data block, the second data block is the next data block adjacent to the first data block, and the second data block carries the data check overhead of the first data block. The demapping module 902 is also used to demap the first data frame to obtain the client signal. It should be understood that the implementation manner of the receiving device 900 can refer to the execution steps of the source device as shown in Figure 6 、7 Execution steps of the host device shown

[0086] Figure 10 Schematic structural diagram of the communication device provided by the embodiment of the present application. The communication device may be a sending device or a receiving device. As Figure 10 shown, the communication device 1000 includes a processor 1001 and a transceiver 1002. The processor 1001 may be a central processing unit (CPU), a network processor (NP), or a combination of a CPU and an NP. The processor 1001 may further include a hardware chip or other general-purpose processor. The above hardware chip may be an application specific integrated circuit (ASIC), a programmable logic device (PLD), or a combination thereof. The transceiver 1002 may be an optical transceiver (or referred to as an optical module).

[0087] When the communication device 1000 is a sending device, the processor 1001 is used to obtain a client signal. The processor 1001 is further used to map the client signal to a first data frame, where the first data frame includes a first data block and a second data block, the second data block is the next adjacent data block of the first data block, and the second data block carries the data check overhead of the first data block. The processor 1001 is further used to map the first data frame to a second data frame. The transceiver 1002 is used to send the second data frame.

[0088] When the communication device 1000 is a receiving device, the transceiver 1002 is used to receive the second data frame. The processor 1001 is used to demap the second data frame to obtain the first data frame, where the first data frame includes a first data block and a second data block, the second data block is the next adjacent data block of the first data block, and the second data block carries the data check overhead of the first data block. The processor 1001 is further used to demap the first data frame to obtain the client signal.

[0089] In other embodiments, the communication device 1000 may further include a memory 1003. The memory 1003 may be a volatile memory or a non-volatile memory, or may include both volatile and non-volatile memories. Among them, the non-volatile memory may be a read-only memory (ROM), a programmable ROM (PROM), an erasable programmable ROM (EPROM), or a flash memory, etc. The volatile memory may be a random access memory (RAM). The memory 1003 may be used to store data frames or other codes for controlling the communication device.

[0090] The above are only the specific embodiments of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present application can easily think of changes or substitutions, which should all be covered within the protection scope of the present application.

Claims

1. A customer signal mapping method, characterized in that, The method includes: The source device obtains a client signal and maps the client signal to a first data frame, where the first data frame includes a first data block and a second data block, the second data block is the next data block adjacent to the first data block, and the second data block carries the data check overhead of the first data block; The source device maps the first data frame to the second data frame and sends the second data frame.

2. The method according to claim 1, wherein The data check overhead is located in the overhead area or the payload area of the second data block.

3. The method according to claim 1 or 2, characterized in that, The first data frame includes multiple 1904-byte data blocks and multiple 1920-byte data blocks, and the 1904-byte data blocks and the 1920-byte data blocks are alternately distributed.

4. The method according to any one of claims 1 to 3, characterized in that, The data check overhead is any one or more of cyclic redundancy CRC check overhead, bit-interleaved parity BIP check overhead, frame check sequence FCS check overhead, etc.

5. The method according to any one of claims 1-4, characterized in that, The first data frame is a small-granularity flexible optical data unit fgODUflex frame.

6. A method for demapping customer signals, characterized in that, The method includes: The downstream device receives the second data frame and demaps the second data frame to obtain the first data frame, where the first data frame includes a first data block and a second data block, the second data block is the next data block adjacent to the first data block, and the second data block carries the data check overhead of the first data block; The downstream device demaps the first data frame to obtain the client signal.

7. The method according to claim 6, characterized in that, The data check overhead is located in the overhead area or the payload area of the second data block.

8. The method according to claim 6 or 7, characterized in that, The first data frame includes multiple 1904-byte data blocks and multiple 1920-byte data blocks, and the 1904-byte data blocks and the 1920-byte data blocks are alternately distributed.

9. The method according to any one of claims 6-8, characterized in that, The data check overhead is any one or more of cyclic redundancy CRC check overhead, bit-interleaved parity BIP check overhead, frame check sequence FCS check overhead, etc.

10. The method according to any one of claims 6-9, characterized in that, The first data frame is transmitted through a working path or a protection path, and the data check overhead is used to instruct the downstream device to select the first data frame corresponding to the working path or the protection path to obtain the client signal.

11. The method according to any one of claims 10, characterized in that, The working path and the protection path include different clock sources, and the data check overhead is used to instruct the downstream device to select the clock source of the working path or the protection path.

12. According to the method described in any one of claims 6-11, characterized in that, The first data frame is a small-granularity flexible optical data unit fgODUflex frame.

13. A transmitting device, characterized in that, The sending device includes: An obtaining module, configured to obtain a client signal; A mapping module, configured to map the client signal to a first data frame, where the first data frame includes a first data block and a second data block, the second data block is the next data block adjacent to the first data block, and the second data block carries the data check overhead of the first data block; The mapping module is further configured to map the first data frame to the second data frame; A sending module, configured to send the second data frame.

14. The transmitting device according to claim 13, wherein The data check overhead is located in the overhead area or the payload area of the second data block.

15. The transmitting device according to claim 13 or 14, characterized in that, The first data frame includes a plurality of data blocks of 1904 bytes and a plurality of data blocks of 1920 bytes, and the data blocks of 1904 bytes and the data blocks of 1920 bytes are alternately distributed.

16. The transmitting device according to any one of claims 13-15, characterized in that, The data check overhead is any one or more of cyclic redundancy CRC check overhead, bit-interleaved parity BIP check overhead, frame check sequence FCS check overhead, etc.

17. The transmitting device according to any one of claims 13-16, characterized in that, The first data frame is a small-granularity flexible optical data unit fgODUflex frame.

18. A receiving device, characterized in that, The receiving device includes: a receiving module, configured to receive a second data frame; a de-mapping module, configured to de-map the second data frame to obtain a first data frame, where the first data frame includes a first data block and a second data block, the second data block is the next adjacent data block of the first data block, and the data check overhead of the first data block is carried in the second data block; The de-mapping module is further configured to de-map the first data frame to obtain a client signal.

19. The receiving device according to claim 18, characterized in that, The data check overhead is located in the overhead area or the payload area of the second data block.

20. The receiving device according to claim 18 or 19, characterized in that, The first data frame includes a plurality of data blocks of 1904 bytes and a plurality of data blocks of 1920 bytes, and the data blocks of 1904 bytes and the data blocks of 1920 bytes are alternately distributed.

21. The receiving device according to any one of claims 18-20, characterized in that, The data check overhead is any one or more of cyclic redundancy CRC check overhead, bit-interleaved parity BIP check overhead, frame check sequence FCS check overhead, etc.

22. The receiving device according to any one of claims 18-21, characterized in that, The first data frame is transmitted through a working path or a protection path, and the data check overhead is used to instruct the downstream device to select the first data frame corresponding to the working path or the protection path to obtain the client signal.

23. The receiving device according to any one of claims 21, characterized in that, The working path and the protection path include different clock sources, and the data check overhead is used to instruct the downstream device to select the clock source of the working path or the protection path.

24. The receiving device according to any one of claims 18-23, characterized in that, The first data frame is a small-granularity flexible optical data unit fgODUflex frame.

25. A communication system, characterized in that, The communication system includes the transmitting device according to any one of claims 13-17 and the receiving device according to any one of claims 18-24.

Images