Bearing frame and bearing method for VC service, and electronic device and storage medium

Abstract

Provided in the present application are a bearing frame and bearing method for a VC service, and an electronic device and a storage medium. The bearing frame is formed by an S code block, a D code block and a T code block, and the bearing frame comprises an overhead area and a bearing area, wherein the overhead area is used for bearing overhead information of a VC service, and the bearing area is used for bearing customer content of the VC service. The bearing frame is mapped to a sub-slot of a service layer for transmission, and one bearing frame is used for bearing one VC service, wherein the VC service is a VC4 service or a VC4-N service, N being an integer greater than or equal to two.

Description

VC service carrying frame, carrying method, electronic device and storage medium

[0001] Cross-references

[0002] This application claims priority to the Chinese patent application filed with the China Patent Office on March 8, 2024, with application number 202410267644.0 and application name “Bearer frame, bearing method, electronic device and storage medium for VC service”. The entire contents of the application are incorporated by reference into this application. Technical Field

[0003] The present application relates to the field of communication technology, and in particular to a bearer frame, a bearer method, an electronic device, and a storage medium for a VC service. Background Art

[0004] The Flexible Ethernet (FlexE) protocol standard technical specification defines a method for delivering customer services at speeds of n (n is a positive integer) * 5G (in bits per second). FlexE physical interfaces can efficiently carry customer services at speeds above 5G. To address the need to carry customer services slower than 5G, the protocol standard also establishes a fine-grained frame structure. This divides a 5G-speed FlexE slot into 480 sub-slots, each with a 10M bandwidth, capable of carrying customer services of 10M or higher.

[0005] For virtual container (VC) services in the Synchronous Digital Hierarchy (SDH) standard, such as VC4 services or VC4-N services, the above-mentioned sub-time slots can also be used for service carrying in related technologies. However, there is currently no relevant solution. Summary of the Invention

[0006] The present application provides a bearer frame, a bearer method, an electronic device, and a storage medium for a VC service.

[0007] This application is implemented as follows:

[0008] In a first aspect, a bearer frame for a VC service is provided, the bearer frame being composed of an S code block, a D code block, and a T code block, the bearer frame including an overhead area and a bearer area; the overhead area being used to carry overhead information of the VC service; the bearer area being used to carry customer content of the VC service; the bearer frame being used to be mapped to a sub-time slot of a service layer for transmission, one bearer frame being used to carry one VC service, the VC service being a VC4 service or a VC4-N service, where N is an integer greater than or equal to 2.

[0009] In a second aspect, a method for carrying VC services based on the bearer frame of the VC services described in the first aspect is provided, which is applied to a transmitting end and includes: mapping the VC services to be carried into the bearer frame, wherein the VC services are VC4 services or VC4-N services; mapping the bearer frame into the sub-timeslot; and sending the sub-timeslot to a receiving end.

[0010] In a third aspect, a method for carrying a VC service based on the bearer frame of the VC service described in the first aspect is provided, which is applied to a receiving end and includes: receiving a sub-time slot sent by a transmitting end; parsing the sub-time slot to extract the bearer frame; parsing the S code block, D code block and T code block in the bearer frame to extract the customer content of the VC service carried by the bearer frame, wherein the VC service is a VC4 service or a VC4-N service.

[0011] In a fourth aspect, an electronic device is provided, comprising: a processor; and a memory for storing instructions executable by the processor; wherein the processor is configured to execute the instructions to implement the method described in the second aspect or the third aspect.

[0012] In a fifth aspect, a computer-readable storage medium is provided. When the instructions in the storage medium are executed by a processor of an electronic device, the electronic device is enabled to execute the method described in the second aspect or the third aspect.

[0013] In a sixth aspect, a computer program product is provided, comprising a computer program stored on a non-transitory computer-readable storage medium, wherein the computer program comprises program instructions, and when the program instructions are executed by a computer, the computer implements the method described in the second aspect or the third aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the technical solutions in this application or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments recorded in this application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0015] Figure 1 shows a schematic diagram of the traditional FlexE protocol combining four 100G optical modules to form a 400G transmission channel;

[0016] FIG2 is a schematic diagram of a data block transmission format of a 100G service in the related art;

[0017] FIG3 is a schematic diagram of code blocks included in a fine-grained frame structure in the related art;

[0018] FIG4 is a schematic diagram of a fine-grained frame structure developed in the related art;

[0019] FIG5 is a schematic diagram of another fine-grained frame structure developed in the related art;

[0020] FIG6 is a schematic diagram of a bearer frame of a VC service provided by an embodiment of the present application;

[0021] FIG7 is a schematic diagram of a bearer frame of a VC service provided by an embodiment of the present application;

[0022] FIG8 is a schematic diagram of a bearer frame of a VC service provided by an embodiment of the present application;

[0023] FIG9 is a schematic diagram of an overhead area provided by one embodiment of the present application;

[0024] FIG10 is a schematic diagram showing a second pointer indication value indicating an increase or decrease of one unit by bit flipping according to an embodiment of the present application;

[0025] FIG11 is a schematic diagram of judging the validity of a second pointer indication value using a majority judgment principle according to an embodiment of the present application;

[0026] FIG12 is a schematic diagram of mapping a bearer frame of a VC service to a sub-time slot for transmission according to an embodiment of the present application;

[0027] FIG13 is a schematic diagram of a VC4 service structure provided by an embodiment of the present application;

[0028] FIG14 is a schematic diagram of 2349 bytes carrying a complete VC4 service in a bearer frame of a VC service provided by one embodiment of the present application;

[0029] FIG15 is a schematic diagram of a bearer frame obtained by multiplexing the H1, H2, and H3 bytes in the AU4 service bearer frame of a VC service provided by one embodiment of the present application;

[0030] FIG16 is a schematic diagram of 2349 bytes of a complete VC4 service carried in a bearer frame of a VC service provided by one embodiment of the present application;

[0031] FIG17 is a schematic diagram of a bearer frame obtained by multiplexing the H1, H2, and H3 bytes in the AU4 service bearer frame of a VC service provided by one embodiment of the present application;

[0032] FIG18 is a schematic diagram of 2349 bytes of a complete VC4 service carried in a bearer frame of a VC service provided by an embodiment of the present application;

[0033] FIG19 is a schematic diagram of 2349 bytes of a complete VC4 service carried in a bearer frame of a VC service provided by an embodiment of the present application;

[0034] FIG20 is a schematic diagram of a bearer frame for transmitting a VC4 service provided by a transmitting end according to an embodiment of the present application;

[0035] FIG21 is a schematic diagram of a VC4-4 service structure provided by an embodiment of the present application;

[0036] FIG22 is a schematic diagram of a VC service bearer frame carrying one-Nth of a VC4-N service according to an embodiment of the present application;

[0037] FIG23 is a schematic diagram of a VC service bearer frame carrying one-Nth of a VC4-N service according to an embodiment of the present application;

[0038] FIG24 is a schematic diagram of a VC service bearer frame carrying a complete VC4-4 service according to an embodiment of the present application;

[0039] FIG25 is a schematic diagram of a VC service bearer frame carrying a complete VC4-4 service according to an embodiment of the present application;

[0040] FIG26 is a schematic diagram of a VC service bearer frame carrying a complete VC4-3 service according to an embodiment of the present application;

[0041] FIG27 is a schematic diagram of a VC service bearer frame carrying a complete VC4-3 service according to an embodiment of the present application;

[0042] FIG28 is a schematic diagram of a VC service bearer frame carrying a complete VC4-2 service according to an embodiment of the present application;

[0043] FIG29 is a schematic diagram of a VC service bearer frame carrying a complete VC4-2 service according to an embodiment of the present application;

[0044] FIG30 is a flow chart of a method for carrying VC services according to an embodiment of the present application;

[0045] FIG31 is a flow chart of a method for carrying VC services according to an embodiment of the present application;

[0046] FIG32 is a schematic structural diagram of an electronic device provided by an embodiment of the present application;

[0047] FIG33 is a schematic structural diagram of a VC service carrying device provided by an embodiment of the present application;

[0048] FIG34 is a schematic structural diagram of a VC service carrying device provided in one embodiment of the present application. DETAILED DESCRIPTION

[0049] The rapid increase in user network traffic is driving the rapid development of information transmission bandwidth in communication networks. The interface bandwidth of communication equipment has increased from 10M (unit: bits per second, the same applies to the following content) to 100M, and then from 100M to 1G and 10G, now reaching 100G bandwidth. 100G optical modules are now widely commercialized. 400G optical modules have been developed, but they are expensive, exceeding the price of four 100G modules, affecting their commercial economic value. To deliver 400G services over 100G optical modules, the International Standards Organization defined the FlexE protocol. The FlexE protocol combines multiple 100G optical modules to form a high-speed transmission channel. As shown in Figure 1, four 100G optical modules can be combined using the FlexE protocol to form a 400G transmission channel, equivalent to the transmission speed of a single 400G module. This addresses the need for 400G service delivery without increasing costs.

[0050] For 100G physical layer services, the Ethernet protocol defines that before transmitting 100G data packets, 64 / 66 encoding is performed on the data packet. This expands the 64-bit data block into a 66-bit information block. The additional two bits are placed at the beginning of the 66-bit block to mark the start of the 66-bit block. The 66-bit blocks are then transmitted from the optical port in 66-bit blocks. During reception, the optical port identifies the 66-bit blocks in the received data stream, recovers the original 64-bit data from the 66-bit blocks, and reassembles the data packet. The FlexE protocol operates below the 64-bit to 66-bit block conversion layer and sorts and arranges the 66-bit data blocks before transmission. As shown in Figure 2, for 100G services, every 20 66-bit data blocks are grouped into a data block group. Each group contains 20 data blocks, representing 20 time slots, with each time slot representing a 5G (bit / s) bandwidth service speed. When sending 66-bit data blocks, a FlexE overhead block (the black block in Figure 2) is inserted after every 1023 data block groups (1023 * 20 data blocks). After inserting the overhead block, data blocks continue to be sent. After sending the second 1023 * 20 data blocks, another overhead block is inserted, and so on. In this way, overhead blocks are periodically inserted during the data block transmission process, with the interval between two adjacent overhead blocks being 1023 * 20 data blocks. For services with a physical line speed of 100G (bit / s), the FlexE protocol divides the physical port into 20 time slots, so the bandwidth corresponding to each time slot is 5G.

[0051] The number of timeslots and bandwidth defined by the FlexE protocol can meet the transmission needs of customer services such as routers and optical transport networks (OTNs). However, applying the FlexE protocol in packet transport networks (PTNs) presents several challenges: 1. A 100G physical channel has only 20 timeslots, which is too few; 2. The bandwidth of each timeslot is 5G, and the granularity of a single timeslot is too large. The FlexE protocol has a relatively small number of timeslots and a relatively large granularity. The basic characteristics of timeslots are fewer timeslots and larger granularity. In the PTN service domain, however, the number of customer services is large, and the bandwidth of each service is relatively small. This means that the number of timeslots is large and the bandwidth granularity of each timeslot is small. This makes the FlexE protocol unsuitable for PTN service applications.

[0052] To address customer service needs at speeds less than 5G, communications network operators have defined technical requirements for fine-grained slicing of packet networks and proposed a fine-grained frame structure. This fine-grained frame structure consists of S-blocks, D-blocks, and T-blocks. These blocks are Ethernet-defined encoding blocks. Figure 3 illustrates the 64 / 66 encoding rules of the Ethernet 802.3 protocol. Each block consists of 66 bits, with the first two bits forming the synchronization header. A synchronization header of "01" indicates a D-block (data block). The following eight bytes (64 bits) contain eight bytes of data. A synchronization header of "10" indicates a control block. The first byte after the synchronization header indicates the control block type, followed by the next seven bytes, which are determined by the control block type.

[0053] As shown in Figure 3, the S block, T block, O block, and idle block (also known as IDLE block, I block, or I-block) all belong to the control block. The first byte of the S block is 0x78, indicating that the control block type is an S block. The S block represents the first block in a data message block stream. The T block represents the last block in a data message block stream and is the end block of the message. In addition to indicating the end block, the T block can also carry client byte content (located in the last 7 bytes of the block). The Ethernet standard divides T code blocks into eight types: T0, T1, T2, T3, T4, T5, T6, and T7. The first byte of a T0 code block is 0x87, and the T0 code block does not carry any client information (or client content). The first byte of a T1 code block is 0x99, and the T1 code block carries one byte of client information. The first byte of a T2 code block is 0xAA, and the T2 code block carries two bytes of client information. The first byte of a T3 code block is 0xB4, and the T3 code block carries three bytes of client information. The first byte of a T4 code block is 0xCC, and the T4 code block carries four bytes of client information. The first byte of a T5 code block is 0xD2, and the T5 code block carries five bytes of client information. The first byte of a T6 code block is 0xE1, and the T6 code block carries six bytes of client information. The first byte of a T7 code block is 0xFF, and the T7 code block carries seven bytes of client information. The IDLE block (also called the I block) is an idle block or an error indication block, and its first byte (i.e., the control word) is 0x1E. The O block is a maintenance block, and its first byte is 0x4B.

[0054] Currently, different fine-grained frame formats (also known as fine-grained bearer frames, small-grained bearer frames, or small-grained frames) have been developed according to different standards. Figure 4 shows a fine-grained frame structure developed in the related art. The fine-grained frame consists of 1 S code block, 195 D code blocks, and 1 T code block. Overhead byte information and 24 sub-time slots are divided on the D code block in a fine-grained frame. A multiframe is organized into 20 fine-grained frames, and there are 480 sub-time slots in a multiframe cycle. Figure 5 shows a fine-grained frame structure developed in a standard document in the related art. The fine-grained frame consists of 1 S code block, 990 D code blocks, and 1 T code block. Overhead byte information and 480 sub-time slots are divided on the D code block in a fine-grained frame. 480 fine-grained frames form a multiframe. Each frame in the multiframe transmits the relevant overhead information of a time slot. The relevant overhead information of 480 sub-time slots is transmitted through 480 fine-grained frames in a multiframe.

[0055] The fine-grained frames shown in Figures 4 and 5 can be carried on the 5G timeslots of the FlexE interface. Each fine-grained frame is divided into 480 sub-timeslots, dividing the bearer channel of a 5G timeslot into 480 sub-timeslots. Each sub-timeslot has a bandwidth of 10 Mbps (actually slightly higher than 10 Mbps). Therefore, a sub-timeslot in a fine-grained frame can carry a 10 Mbps customer service, which basically meets the carrying requirements of ordinary Ethernet services (current Ethernet service bandwidths include 10 Mbps, 100 Mbps, 1 Mbps, and above, and services greater than 10 Mbps are carried using multiple sub-timeslots). When a fine-grained sub-timeslot carries a 10 Mbps customer service, the 10 Mbps customer service is first 64 / 66 encoded. After encoding, some sub-timeslots are selected for carrying. The fine-grained frame is then mapped to the FlexE protocol timeslot and transmitted, and then delivered to the remote destination device via the 5G timeslots of the FlexE protocol.

[0056] The aforementioned fine-grained slicing technology for the packet network is required to carry 10M customer services. However, in some application scenarios, the device needs to replace SDH equipment and carry various VC services in the SDH system. However, no solution has been considered to achieve the carrying of VC services.

[0057] The embodiment of the present application proposes a bearer frame, a bearing method, an electronic device, and a storage medium for VC services. The bearer frame is composed of an S code block, a D code block, and a T code block. The bearer frame includes an overhead area and a bearer area. The overhead area is used to carry the overhead information of the VC service, and the bearer area is used to carry the customer content of the VC service. The bearer frame is used to be mapped to the sub-timeslot of the service layer for transmission. One bearer frame is used to carry one VC service, and the VC service is a VC4 service or a VC4-N service, where N is an integer greater than or equal to 2. In this way, when carrying a VC4 service or a VC4-N service in a sub-timeslot based on the FlexE protocol standard, the VC4 service or VC4-N service to be carried can be mapped to the bearer frame, and then the bearer frame can be mapped to the sub-timeslot for transmission. Thus, the carrying of the VC4 service or VC4-N service can be realized, and the carrying requirements for the VC4 service or VC4-N service can be met.

[0058] In order to help those skilled in the art better understand the technical solutions of this application, the following will clearly and completely describe the technical solutions of this application in conjunction with the drawings of one or more embodiments of this application. Obviously, the described embodiments are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of this application.

[0059] The terms "first," "second," and the like in this application and the claims are used to distinguish similar objects and are not used to describe a particular order or precedence. It should be understood that such terms are interchangeable where appropriate so that this application can be implemented in sequences other than those illustrated or described herein. In addition, the term "and / or" in this application and the claims refers to at least one of the connected objects, and the character " / " generally indicates that the connected objects are in an "or" relationship.

[0060] FIG6 is a schematic diagram of a bearer frame for a VC service provided by an embodiment of the present application. The bearer frame may be used to carry a VC4 service or a VC4-N service, where N is an integer greater than or equal to 2.

[0061] As shown in Figure 6, the bearer frame of the VC service provided by the embodiment of the present application is composed of an S code block, a D code block and a T code block. Among them, the S code block, the D code block and the T code block are code blocks of 66 bits in length defined by the Ethernet 802.3 international standard. The S code block is the starting code block of the bearer frame, and the number of S code blocks is 1. The D code block is the intermediate code block of the bearer frame, which is a data code block and can be used to carry customer content. One D code block can carry 8 bytes of customer content. The data of the D code block is n (n is an integer greater than 1), which can be determined according to the customer content that needs to be carried. The T code block is the intermediate code block of the bearer frame, and the data of the T code block is 1. Specifically, it can be any one of the T0 code block, T1 code block, T2 code block, T3 code block, T4 code block, T5 code block, T6 code block and T7 code block defined in the Ethernet standard.

[0062] The bearer frame for VC services includes an overhead area and a bearer area (not shown in Figure 6). The overhead area carries overhead information for the VC service (denoted as OH, meaning overhead). The overhead information indicates the characteristics of the bearer frame structure. The overhead area can include multiple bytes, such as 2, 3, or 4 bytes, though this is not specifically defined. The overhead area can be located in an S code block, in a D code block (for example, in the first D code block), or in both an S code block and a D code block (for example, in both an S code block and the first D code block).

[0063] The bearer area is used to carry customer content of VC services, and can be located in the D code block, or in the S code block and the D code block, or in the D code block and the T code block, or in the S code block, the D code block and the T code block. In some embodiments, the bearer area includes a bearer adjustment area and a fixed bearer area. In other embodiments, the bearer area may only include a fixed bearer area and not include a bearer adjustment area. In the case where the bearer area includes a bearer adjustment area, the bearer adjustment area may be located in the S code block, or in the D code block, or in the S code block and the D code block, and may carry customer content or not. Since the bearer adjustment area may carry or not carry customer content, the bearer adjustment area may be used to adjust the number of bytes carried for customer content. Whether the bearer adjustment area carries customer content can be determined based on the customer service speed that needs to be carried, and is not specifically limited here. The bearer adjustment area may include one or more bytes. If the bearer adjustment area includes multiple bytes, when carrying (or not carrying) customer content, it may be that some of the bytes carry (or not carry) customer content, or it may be that all of the bytes carry (or not carry) customer content, and this is not specifically limited here. If some of the bytes carry (or not carry) customer content, the bytes may be located at any position in the bearer adjustment area, and this is not specifically limited here. For example, if the bearer adjustment area includes two bytes, and one byte carries customer content and the other does not, it may be that the first byte carries customer content and the second byte does not, or it may be that the first byte does not carry customer content and the second byte carries customer content. In an exemplary implementation, whether to carry customer content in the bearer adjustment area can be determined based on the speed of the customer service to be carried, and the overhead information in the overhead area indicates the number of bytes in the bearer adjustment area used to carry customer content. The entire area of ​​the fixed bearer area is used to carry customer content and is not affected by the customer service speed. The fixed bearing area may include multiple bytes and may be located in a D code block, or in an S code block and a D code block, or in a D code block and a T code block, or in an S code block, a D code block and a T code block.

[0064] In some implementations, the bearer frame of a VC service may further include a fixed stuffing area. The fixed stuffing area is an invalid area that does not carry clients and can be set as needed. For example, when the bearer area in the bearer frame is too large, some fixed stuffing areas may be set to reduce the number of bytes in the bearer area used to carry client content, that is, to reduce the number of bytes carried in the effective bearer area. The fixed stuffing area may be located in the D code block, and the number of bytes may be 0 or more. 0 indicates that there is no fixed stuffing area, that is, the bearer area of ​​the bearer frame is just the right size to carry bytes and is not too large. There is no need to set a fixed stuffing area to reduce the size of the effective bearer area.

[0065] Figure 7 is a schematic diagram of the bearer frame of the VC service provided by an embodiment of the present application. The bearer frame shown in Figure 7 is composed of 1 S code block, n D code blocks and 1 T code block, and the T code block is a T7 code block. The overhead area (the OH area shown in Figure 7) is located in the S code block and includes a total of 7 bytes. The fixed stuffing area (the area where the black box shown in Figure 7 is located) is located in the first D code block and includes a total of 5 bytes. The bearer adjustment area (the area where the asterisk box shown in Figure 7 is located) is located in the first D code block and includes 2 bytes, the first byte is the -adjustment area, and the second byte is the +adjustment area. The fixed bearer area (the white box shown in Figure 7) is located in the D code block and the T code block.

[0066] Figure 8 is a schematic diagram of the bearer frame of the VC service provided by an embodiment of the present application. The bearer frame shown in Figure 8 consists of 1 S code block, n D code blocks and 1 T code block, and the T code block is a T7 code block. The overhead area (the OH area shown in Figure 8) is located in the first D code block and includes a total of 5 bytes. The fixed stuffing area (the area where the black box shown in Figure 8 is located) is located in the first D code block and includes a total of 1 byte. The bearer adjustment area (the area where the asterisk box shown in Figure 8 is located) is located in the first D code block and includes 2 bytes, the first byte is the -adjustment area, and the second byte is the +adjustment area. The fixed bearer area (the white box shown in Figure 8) is located in the D code block and the T code block.

[0067] It should be noted that Figures 7 and 8 are exemplary illustrations of the bearer frame of the VC service provided in the embodiment of the present application. In other possible implementations, the structure of the bearer frame may also be in other forms other than Figures 7 and 8. For example, the bearer frame shown in Figures 7 and 8 may not include a bearer adjustment area, or may not include a fixed insertion area, or the T code block may be a code block of other types, etc., and examples will not be given one by one here.

[0068] The bearer frame of the VC service can be used to be mapped to the sub-timeslot of the service layer for transmission. One bearer frame can be used to carry one VC4 service or one VC4-N service. Specifically, when a bearer frame is used to carry one VC4-N service, it can be used to carry part of the VC4-N service (such as one-Nth of the service) or all of the VC4-N service. When mapping the bearer frame to the sub-timeslot for transmission, when a bearer frame is used to carry one VC4 service or one-Nth of the VC4-N service, one bearer frame can be mapped to 15 or 16 sub-timeslots for transmission. When a bearer frame is used to carry all of the VC4-N service, one bearer frame can be mapped to N*15 or N*16 sub-timeslots for transmission.

[0069] Based on the bearer frame provided in the embodiment of the present application, when it is necessary to carry a VC4 service or a VC4-N service in a sub-time slot, one VC4 service or VC4-N service to be carried can be mapped to the bearer frame, and then the bearer frame is mapped to the sub-time slot for transmission. In this way, the carrying of the VC4 service or VC4-N service can be realized, meeting the carrying requirements for the VC4 service or VC4-N service.

[0070] In some implementations, the overhead information carried by the overhead area may include at least one of the following:

[0071] SDH frame overhead content, used to carry the regenerator section layer and multiplex section layer overhead;

[0072] The first pointer indication value is used to indicate whether the second pointer indication value has changed abnormally;

[0073] The second pointer indication value is used to indicate the location information of the client's specific content in the bearer frame.

[0074] The SDH frame overhead content, the first pointer indication value, and the second pointer indication value may each include one or more bytes, which is not specifically limited here.

[0075] The overhead of the regeneration section layer and the multiplexing section layer has been explained in traditional standard protocols and will not be described in detail here.

[0076] The second pointer indicator value, also known as the client-specific content location pointer value, can be used to indicate the location of the client service-specific content carried in the bearer frame. This serves as location information. For VC4 services, the client service-specific content can be the first overhead byte (e.g., the J1 byte) within the VC4 service content, or other byte content, without specific limitations here. For VC4-N services, the client service-specific content can be the first N overhead bytes (e.g., N J1 bytes) within the VC4-N service content, or other byte content, without specific limitations here. The location of the client-specific content within the bearer frame can be fluid, and therefore the second pointer indicator value can vary. Typically, changes in the second pointer indicator value are relatively small, representing normal fluctuations and not abnormal changes. However, in abnormal situations (such as service interruptions), the second pointer indicator value can change significantly, representing abnormal fluctuations. To facilitate detection of abnormal fluctuations in the second pointer indicator value, the first pointer indicator value can be used in the overhead area of ​​the bearer frame to indicate whether the second pointer indicator value has changed abnormally.

[0077] Optionally, in some implementations, the overhead information carried by the overhead area may further include at least one of the following:

[0078] Multiframe indication, used to indicate the sequence relationship of multiple bearer frames in a multiframe group;

[0079] Customer number, used to distinguish different bearer frames carrying different customer services;

[0080] Customer type, used to characterize the service type carried by the bearer frame;

[0081] Cyclic Redundancy Check (CRC) field.

[0082] The multiframe indication, client number, client type and CRC fields may each include one or more bytes, which are not specifically limited here.

[0083] A multiframe group can include multiple bearer frames. For a bearer frame, if it forms a multiframe group with other bearer frames, the bearer frame's overhead information may include a multiframe indicator. The multiframe indicator can be represented by a sequence value, such as frame 0, frame 1, frame 2, frame 3, etc., or by other means. Examples are not provided here.

[0084] Different bearer frames can carry VC services of different customers. When multiple bearer frames carry VC services of multiple customers, the overhead information in each bearer frame can include a customer number to distinguish different bearer frames carrying different customer services by the customer number.

[0085] The customer type is used to indicate the service type of the customer service carried by the bearer frame. For a bearer frame carrying VC service, the overhead information may include the customer type to indicate that the service type carried by the bearer frame is VC4 service or VC4-N service, not VC12, VC3, or VC11 type customer service.

[0086] In actual applications, the overhead information carried in the overhead area can be any one or more of the seven items of overhead information (i.e., SDH frame overhead content, first pointer indicator value, second pointer indicator value, multiframe indicator, customer number, customer type, and CRC field) described above. The specific order can be determined based on actual service requirements and is not specifically limited here. The number of bytes occupied by each item of overhead information can also be determined based on actual service requirements and is not specifically limited here. In an exemplary implementation, when the overhead area carries the seven items of overhead information described above, the overhead area can be as shown in FIG9 . In FIG9 , each item of overhead information occupies one byte, and each of the seven items of overhead information occupies seven bytes, meaning that the overhead area occupies a total of seven bytes. The order of the overhead information in the overhead area can be the order shown in FIG9 , or, of course, other orders, which are not specifically limited here.

[0087] In the case of the bearer frame of the VC service provided by the embodiment of the present application carrying the VC4 service or the VC4-N service, the bearer area in the bearer frame may include a bearer adjustment area and a fixed bearer area, or may include only the fixed bearer area but not the bearer adjustment area. In the case where the bearer area only includes the fixed bearer area, the overhead area may not include the first pointer indication value and the second pointer indication value, and the customer's specific content is in a fixed position in the bearer area. In the case where the bearer area includes the bearer adjustment area and the fixed bearer area, the overhead area may include the first pointer indication value and the second pointer indication value, so that the second pointer indication value indicates the position information of the customer's specific content in the bearer frame and the first pointer indication value indicates whether the second pointer indication value has undergone abnormal changes.

[0088] In some implementations, when the bearer area includes a bearer adjustment area, the aforementioned second pointer indicator value can also be used to indicate a change in the number of bytes used to carry the customer content in the bearer adjustment area. In other words, the second pointer indicator value can have two functions: first, indicating the location of the customer's specific content in the bearer frame, and second, indicating the number of bytes used to carry the customer content in the bearer adjustment area.

[0089] When the second pointer indicator value indicates the position of the client's specific content in the bearer frame and the number of bytes in the bearer adjustment area used to carry the client's content, in some embodiments, the indication may be performed in the following manner:

[0090] When the second pointer value increases by one, the position information of the client's specific content in the bearer frame moves backward by one unit, and the number of bytes used to carry the client's content in the bearer adjustment area decreases by one unit (the second pointer value increase indication information at this time = the bearer area adjustment decrease information);

[0091] When the second pointer indicates a value decreasing by one, the position information of the client's specific content in the bearer frame moves forward by one unit, and the number of bytes used to carry the client's content in the bearer adjustment area increases by one unit (the second pointer indicates a value decreasing at this time = the bearer area adjustment increase information);

[0092] When the second pointer indication value remains unchanged, the position information of the customer's specific content in the bearer frame remains unchanged, and the number of bytes used to carry the customer content in the bearer adjustment area remains unchanged (the second pointer indication value at this time is stable and unchanged indication information = the bearer area is adjusted to maintain the original stable value).

[0093] The above-mentioned one unit may be one byte or multiple bytes.

[0094] The position information of the client-specific content in the bearer frame is shifted forward or backward by one unit. This can be done by shifting the byte position occupied by the client-specific content in the bearer frame forward or backward by one unit. For example, if the position information of the client-specific content in the bearer frame is the fifth byte of the second D-code block, and assuming that one unit represents one byte, then after the position information of the client-specific content in the bearer frame is shifted forward by one unit, the new position information is the fourth byte of the second D-code block. After the position information of the client-specific content in the bearer frame is shifted backward by one unit, the new position information is the sixth byte of the second D-code block.

[0095] The bearer adjustment area may include at least two units of bytes. For example, when one unit represents one byte, the bearer adjustment area may include at least two bytes, and when one unit represents three bytes, the bearer adjustment area may include at least six bytes. In some embodiments, the bearer adjustment area may include two areas, namely a first adjustment area and a second adjustment area, and the first adjustment area and the second adjustment area may each include one unit of bytes (i.e., each includes one or more bytes). When the second pointer indication value is increased by one, neither the first adjustment area nor the second adjustment area carries customer content. When the second pointer indication value is decreased by one, both the first adjustment area and the second adjustment area carry customer content. When the second pointer indication value remains unchanged, the first adjustment area does not carry customer content, and the second adjustment area carries customer content.

[0096] For easier understanding, please refer to Figures 7 and 8. In Figures 7 and 8, the bearer adjustment area consists of two bytes: the - adjustment area and the + adjustment area. The - adjustment area can be considered the first adjustment area mentioned above and includes one byte, while the + adjustment area can be considered the second adjustment area mentioned above and includes one byte. Under normal and stable conditions, the second pointer indicates a stable value, and the bearer adjustment area maintains a stable bearer mode. In this stable bearer mode, the - adjustment area does not carry any customer content, and only the + adjustment area carries customer content. This state is called a stable bearer state. When the customer service speed is high and more customer content needs to be carried, the second pointer indicates a decrease of one unit, and the bearer adjustment area enters an increase bearer mode. In this increase bearer mode, both the - adjustment area and the + adjustment area carry customer content, with the - adjustment area carrying an additional unit of customer content compared to the normal stable state. Because the - adjustment area carries one more unit of customer content, all customer content in the bearer area must be shifted forward by one unit, and the customer-specific content (such as the J1 byte) is also shifted forward by one unit. The new position is the result of the second pointer indicating a decrease of one unit, and the second pointer indicates the new position of the customer-specific content. When the customer service speed is relatively slow and less customer content needs to be carried, the second pointer indication value indicates an increase of one unit, and the carrying adjustment area changes to a reduced carrying mode. In the reduced carrying mode, neither the - adjustment area nor the + adjustment area carries customer services, and the + adjustment area carries less customer content than in the normal stable state. Since the carrying adjustment area carries one unit less customer content, all customer content in the carrying area needs to be moved back one unit in turn, and the customer's specific content (such as the J1 byte) is also moved back one unit. The new position is the result of the second pointer indication value being increased by one unit, and the second pointer indication value indicates the new position of the customer's specific content.

[0097] In Figures 7 and 8 , the -adjustment area and the +adjustment area each comprise one byte. In other implementations, the -adjustment area and the +adjustment area may also comprise 2 bytes, 3 bytes, 4 bytes, 5 bytes, 6 bytes, etc. When both the -adjustment area and the +adjustment area are 2 bytes in size, this is equivalent to adding 2 bytes each time the bytes used to carry customer content are increased, and subtracting 2 bytes each time the bytes used to carry customer content are decreased. Similarly, when both the -adjustment area and the +adjustment area are 3 bytes in size, this is equivalent to adding 3 bytes each time the bytes used to carry customer content are increased, and subtracting 3 bytes each time the bytes used to carry customer content are decreased.

[0098] Changes in the second pointer indicator value indicate changes in the number of valid bytes carrying customer content in the bearer adjustment area, specifically, whether the number of valid bytes carrying customer content has increased or decreased compared to the previous number. In practical applications, when the clock frequency of a VC4 or VC4-N service is generally stable, the VC4 or VC4-N service speed is allowed to remain stable within a certain range while meeting clock jitter and drift requirements. Any changes are slow. Accordingly, the number of bytes used to carry customer content in the bearer adjustment area for a VC4 or VC4-N service is generally stable, and any changes are slow. Therefore, changes in the second pointer indicator value are also slow, meaning that the second pointer indicator value changes by only one unit at a time (i.e., plus or minus one). The new second pointer indicator value is typically plus or minus one compared to the previous value, with a limited range of variation. Therefore, when the second pointer indicator value changes, it is not necessary to immediately indicate the second pointer indicator value; it is sufficient to indicate whether the change is an increase, decrease, or no change.

[0099] Based on this idea, in some embodiments, the second pointer indication value can indicate the position information of the customer's specific content in the bearer frame and the change in the number of bytes used to carry the customer content in the bearer adjustment area by the change in the value of the bit at a specific position.

[0100] In an exemplary embodiment, taking the example of a second pointer indicator value comprising W bits (W may be an integer greater than or equal to 4), the W bits may be divided into two groups, namely a first group of bits and a second group of bits (the two groups of bits may or may not overlap), the first group of bits comprising P bits (P is an integer greater than or equal to 1 and less than W), and the second group of bits comprising Q bits (Q is an integer greater than or equal to 1 and less than W, and Q and P may be equal or unequal). If at least half of the P bits (rounded up to a maximum of P) are flipped, the second pointer indicator value is used to indicate that the position information of the client's specific content in the bearer frame is shifted backward by one unit, and the number of bytes in the bearer adjustment area used to carry the client's content is reduced by one unit. If at least half of the Q bits (rounded up to a maximum of Q) are flipped, the second pointer indicator value is used to indicate that the position information of the client's specific content in the bearer frame is shifted forward by one unit, and the number of bytes in the bearer adjustment area used to carry the client's content is increased by one unit. When the W bit values ​​remain unchanged, the second pointer indicator value indicates that the location information of the client's specific content in the bearer frame remains unchanged, and the number of bytes used to carry the client content in the bearer adjustment area remains unchanged.

[0101] For ease of understanding, the following description is given using FIG. 10 as an example.

[0102] The second pointer indication value shown in FIG10 is a 10-bit value. This 10-bit value can be divided into two groups according to even positions and odd positions: the five bits in the even positions (i.e., b9, b7, b5, b3, b1) form one group, and the five bits in the odd positions (i.e., b8, b6, b4, b2, b0) form another group. When the second pointer indication value changes, only the information of whether the change is increased or decreased is required. For example, a group of five bits in the even positions can indicate an increase in the change indication information, and a group of five bits in the odd positions can indicate a decrease in the change indication information (or, a group of five bits in the even positions can indicate a decrease in the change indication information, and a group of five bits in the odd positions can indicate an increase in the change indication information). When the second pointer indication value needs to be increased by 1, all five bits in the even positions are flipped, indicating an increase in the change indication information. When the second pointer indication value needs to be decreased by 1, all five bits in the odd positions are flipped, indicating a decrease in the change indication information. After a bit flip in the even or odd group, the next value is the new one. After all five bits in the even position flip, the next second pointer indicator value is the previous historical stable value plus one. After all five bits in the odd position flip, the next second pointer indicator value is the previous historical stable value minus one. Bit flips in the even or odd group indicate a new second pointer indicator value. At the receiving end, when the second pointer indicator value is inconsistent with the previous historical value, the bit changes in the even or odd group are analyzed separately. If the bits in the even group flip with the even bits in the previous value, the second pointer indicator value has changed by one, and the new second pointer indicator value is the result of adding one to the previous value. If the bits in the odd group flip with the odd bits in the previous value, the second pointer indicator value has changed by one, and the new second pointer indicator value is the result of subtracting one from the previous value. To avoid misjudgment in the event of a single-bit error, whether the five bits in each group have flipped can be determined by majority rule. For example, if any three of the five bits flip, it is determined that the bits in that group have flipped. If any three bits among the five bits are not flipped, it is determined that the group of bits is not flipped and the original value is retained. In this way, even if two bits of the pointer value are wrong, no misjudgment will occur during transmission.

[0103] It should be noted that the above two implementation methods are used as examples to illustrate how the second pointer indication value indicates the location information of the customer's specific content in the bearer frame and the change in the number of bytes used to carry the customer content in the bearer adjustment area. In other possible implementation methods, other indication methods can also be used for indication. Other possible indication methods will not be given one by one here.

[0104] In some embodiments, the second pointer indicator value can take effect in the current frame. After receiving the bearer frame, the receiving end can determine the location information of the customer's specific content in the current bearer frame and the number of bytes used to carry the customer content in the bearer adjustment area based on the second pointer indicator value in the bearer frame. However, in actual applications, the second pointer indicator value may cause an error due to a bit error, thereby indicating erroneous information. For the receiving end, this will also lead to an erroneous judgment result, causing the receiving end to make an error when performing service bearer recovery based on the second pointer indicator value. In order to reduce the erroneous judgment caused by the bit error, in some embodiments, the sending end can transmit the second pointer indicator value multiple times, and the receiving end can use the majority judgment principle to determine the final second pointer indicator value.

[0105] When the majority judgment principle is used to determine the final second pointer indication value, in some embodiments, the majority judgment principle may be such that, if the second pointer indication values ​​in L bearer frames out of M consecutive bearer frames undergo the same change, the second pointer indication value takes effect in the last frame of the M bearer frames. M is an integer greater than or equal to 3, and L is an integer greater than or equal to M / 2 and less than or equal to M. For example, when M is 3, L may be 2, and when M is 4, L may be 3.

[0106] For ease of understanding, please refer to Figure 11. Figure 11 illustrates the example of the second pointer indication value taking effect only once every four frames. In an exemplary embodiment, every four consecutive bearer frames can be regarded as a multiframe group, and in each multiframe group, the multiframe sequence values ​​of the four bearer frames are "00", "01", "10" and "11" respectively. For the transmitting end, when sending a bearer frame to the receiving end, the new second pointer indication value can be transmitted in all four bearer frames of the multiframe group (there may be a bit error). At the receiving end, for the bearer frames in a multiframe group, the three bearer frames with multiframe sequence values ​​of "00", "01" and "10" operate according to the historical second pointer indication value, but at the same time, the second pointer indication value carried by these three frames and the frame with a multiframe sequence of "11" is extracted. In the case of a single-bit error, even if a bit error occurs and causes one of the values ​​to be wrong, the other three values ​​are correct and the values ​​are completely consistent. According to the majority judgment principle, the three identical second pointer indication values ​​are the updated second pointer indication values, and the updated second pointer indication value will take effect in the frame with a multiframe sequence value of "11", that is, the updated second pointer indication value is used in the frame with a multiframe sequence value of "11" to determine the location information of the customer-specific content and the number of bytes used to carry the customer content in the bearer adjustment area, and the customer content status carried by the bearer adjustment area is determined according to this value and the customer content is extracted. Since the four frames of "00", "01", "10" and "11" all have second pointer indication values, the second pointer indication values ​​of any three frames are selected from these four second pointer indication values ​​for majority judgment principle and the final second pointer indication value is given. This can reduce the erroneous judgment caused by bit errors, ensure the correctness of the receiving end when restoring the service bearer according to the second pointer indication value, and avoid service errors.

[0107] It should be noted that, for the four carrying frames of the above-mentioned multi-frame group, when using the majority judgment principle to judge the second pointer indication value, in addition to using three frames for judgment, two frames can also be used for judgment. That is to say, as long as the second pointer indication values ​​of at least two frames among the four frames have changed and are consistent, it can be considered that the second pointer indication value has changed and takes effect in the last frame.

[0108] Based on the bearer frame of the VC service provided in the embodiment of the present application, when carrying VC4 service or VC4-N service, the format of the bearer frame can be first determined, and then the VC4 service or VC4-N service can be encapsulated according to the format, that is, the VC4 service or VC4-N service is mapped into the bearer frame, and finally the bearer frame is mapped into the sub-time slot of the service layer for transmission. Among them, before the bearer frame is mapped into the sub-time slot, idle code blocks and operation, administration and maintenance (OAM) code blocks can be inserted between the bearer frames. In an exemplary embodiment, the process can be shown in Figure 12. In Figure 12, after the VC4 service or VC4-N service is mapped into the bearer frame, a certain number of idle code blocks (IDLE code blocks, or I blocks or I blocks for short) can be inserted between the bearer frames. In this way, the intermediate network device nodes in the network can adapt to the clock deviation between different network device nodes by adding or deleting idle code blocks. In order to monitor the service quality of the service layer during the bearer transmission process, such as delay time and bit error status, idle code blocks can be inserted between bearer frames. An appropriate number of OAM code blocks (abbreviated as o-code blocks, o-blocks) can also be inserted between bearer frames. After inserting IDlE blocks and o-blocks between bearer frames, they are sent out through the fine-grained pipe bearer formed by the service layer sub-time slots.

[0109] When determining the format of a bearer frame, in an exemplary embodiment, a bearer frame consists of one S code block, multiple D code blocks, and one T code block. The S code block is a frame header marker block, the D code block is a data block, and the T code block is an end marker block. The bearer frame includes an overhead area and a bearer area. The bearer area includes a bearer adjustment area and a fixed bearer area, or the bearer area includes only a fixed bearer area but does not include the bearer adjustment area. The overhead area carries overhead information. The bearer adjustment area is a dynamic area that may or may not carry customer services, and the specific determination can be made based on the speed of the customer services to be carried. The fixed bearer area carries customer services at all locations and is not affected by the speed of the customer services. Optionally, when the bearer capacity of the bearer frame is too large, a fixed stuffing area can be set in the bearer frame. The fixed stuffing area does not carry customer services. When the bearer capacity of the bearer frame is just right, the fixed stuffing area can be omitted from the bearer frame.

[0110] The length of a bearer frame is a key characteristic of a bearer frame. It is determined by the number of D blocks in the bearer frame and is related to the bearer frame's carrying efficiency. The bearer frame's carrying efficiency is the ratio of the number of bytes in the bearer frame used to carry customer services to the total number of bytes in the bearer frame. Because the overhead area, fixed insertion area, control word portion of the S block, and control word portion of the T block in the bearer frame do not carry customer services, the bearer frame's carrying efficiency is less than 100%. Generally speaking, the greater the number of D blocks in a bearer frame, the longer the bearer frame length, and the greater the number of bytes in the bearer frame used to carry customer services, the higher the bearer frame's carrying efficiency. When carrying VC4 or VC4-N services, the required carrying efficiency of the bearer frame can be determined based on the desired VC service's client speed and the selected number of service layer subslots (the number of service layer subslots is equivalent to the total service layer rate). Based on this carrying efficiency requirement, the number of D blocks in the bearer frame is determined, which in turn determines the bearer frame length and ultimately the bearer frame format.

[0111] Figure 13 shows the VC4 service structure in the SDH system standard. A VC4 service consists of nine groups, each consisting of one overhead byte and 260 content bytes, totaling 261 bytes per group and 2349 bytes in all nine groups. The first byte of a VC4 service is the J1 byte. The VC4 service speed is 150.336 Mbps. The nominal speed of a sub-timeslot in a fine-grained frame is 10 Mbps (in bits per second), with the actual speed slightly exceeding 10 Mbps. One Slicing Packet Network (SPN) standard is 10.1 Mbps, which has a 1% bandwidth margin over 10 Mbps. Therefore, at least 15 sub-timeslots are required in a fine-grained frame to carry one VC4 client service. In some implementations, 15 or 16 sub-timeslots can be used to carry one VC4 service. When 15 sub-timeslots are used to carry one VC4 service, the carrying efficiency of the VC4 service bearer frame must reach at least 150.336 / (15*10.1)=99.2317%, so that 15 10.1M sub-timeslots can carry one VC4 service. When 16 sub-timeslots are used to carry one VC4 service, the carrying efficiency of the VC4 service bearer frame must reach at least 150.336 / (16*10.1)=93.03%, so that 16 10.1M sub-timeslots can carry one VC4 service (if calculated based on a 10M speed per sub-timeslot, the carrying efficiency of the VC4 service bearer frame must reach at least 150.336 / (16*10)=93.96%), so that 16 10M sub-timeslots can carry one VC4 service). Of course, in other possible implementations, more sub-timeslots may be used to carry one VC4 service. The specific number may be determined based on the actual application scenario and is not specifically limited here. The embodiments of this application are described using 15 or 16 sub-timeslots carrying one VC4 service as an example.

[0112] When a bearer frame is used to carry a VC4 service, in some implementations, a bearer frame can be composed of 1 S code block, 293 D code blocks, and 1 T code block. The overhead area of ​​the bearer frame can be located in the S code block, and the bearer area of ​​the bearer frame can be located in the S code block, the D code block, and the T code block. The bearer area includes a 6-byte bearer adjustment area and a 2346-byte fixed bearer area. The first 3 bytes of the bearer adjustment area are the first adjustment area, and the last 3 bytes are the second adjustment area. The fixed bearer area includes 782 groups of bytes, each group of bytes includes 3 bytes, and the J1 byte of the VC4 service is located at the first position of one of the groups of bytes. For details, please refer to Figure 14.

[0113] Figure 14 is a schematic diagram of a VC4 service bearer frame carrying 2349 bytes of a complete VC4 service. The bearer frame shown in Figure 14 consists of one S code block, 293 D code blocks, and one T code block. The bearer frame's overhead area includes six bytes (the OH area in Figure 14), located within the S code block. The bearer adjustment area of ​​the bearer frame consists of a - adjustment area and a + adjustment area. The - adjustment area includes three bytes, and the + adjustment area includes three bytes. The two adjustment areas have a total adjustment capacity of six bytes. The bearer area contains a fixed bearer area of ​​3*782=2346 bytes. In actual applications, the bearer area can be grouped, with each adjacent three bytes forming a group. For example, the three bytes in the - adjustment area form a group, and the three bytes in the + adjustment area form a group. In the fixed bearer area, each consecutive three bytes form a group. The 2346 bytes are divided into 782 groups: the first, second, and third bytes form a group, the fourth, fifth, and sixth bytes form a group, the seventh, eighth, and ninth bytes form a group, and so on. Similarly, the 2344th, 2345th, and 2346th bytes form a group, as shown in Figure 14. The overhead byte J1 in the VC4 service can be located at a fixed byte position within a group of bytes in the fixed bearer area. For example, as shown in Figure 14, the J1 byte is fixed at the first byte position in the second group of bytes.

[0114] During normal transmission, the bearer frame shown in Figure 14 does not carry customer services in the - adjustment area. Customer services are carried in the 2346 byte positions in the + adjustment and fixed bearer areas, for a total of 2349 bytes. This bearer frame can precisely carry the 2349 bytes of a VC4 service. In this case, the bearer frame's carrying efficiency is 99.53% (excluding the insertion of idle code blocks), meeting the 99.2317% carrying efficiency requirement. When a complete VC4 service content is carried in a bearer frame, the VC4 service can float every three bytes within the bearer frame. The group number of the first J1 byte of the VC4 service is not fixed, but its position within the group is fixed, for example, only the first byte within the group. The customer-specific content location pointer value (i.e., the second pointer indicator value) in the overhead area can indicate the group number position of the J1 byte. In Figure 14 , the J1 byte is located at the first byte position of the second D code block in the bearer frame. If the - adjustment area position is used as a reference, and the - adjustment area position is defined as the 0th byte group position, then the + adjustment area position is the 1st byte group position. Similarly, the J1 byte position in Figure 14 is the 3rd byte group position, and the client-specific content location pointer value in the overhead area can be equal to 3. At the receiving end, when the client-specific content location pointer value is extracted as 3, the client-specific content location pointer value remains unchanged from its previous value. This indicates that the - adjustment area does not carry any customer service, and that customer service begins to be carried in the + adjustment area. That is, the VC4 service is carried in the 2346 byte positions of the + adjustment area and the fixed bearer area, and the first J1 byte in the customer service is at the first byte position of the 3rd byte group.

[0115] When the VC4 customer service speed is relatively slow, the customer-specific content position pointer value increases by 1. In the bearer frame of the VC4 service, neither the - adjustment area nor the + adjustment area carries customer services. Only the 2346-byte fixed bearer area carries customer services. Each VC4 service bearer frame carries only 2346 bytes of VC4 services, reducing the number of carried customer services and adapting to the slow VC4 service speed. The first J1 byte position in the customer service also lags behind by one group position.

[0116] When the speed of a VC4 service is too high, the client-specific content position pointer value decreases by 1. In the VC4 service bearer frame, the - adjustment area, the + adjustment area, and the 2346-byte fixed bearer area all carry the customer service. Each VC4 service bearer frame carries a total of 2352 bytes of VC4 service. The bearer space becomes larger to accommodate the faster VC4 service. The first J1 byte in the customer service is also moved forward by one group position to carry the service.

[0117] In the SDH architecture, an AU4 consists of 2349 bytes, including H1, H2, and H3 bytes, and VC4. H1 is a single byte with a valid value (the contents of the second and third H1 bytes are ignored and invalid, equivalent to the absence of the second and third H1 bytes). H2 is a single byte (the contents of the second and third H2 bytes are ignored and invalid, equivalent to the absence of the second and third H2 bytes). The H3 byte position is three bytes. The H1 and H2 bytes form a pointer value, indicating the position of the J1 byte relative to the H3 byte in the AU4. When the pointer value of the combined H1 and H2 bytes decreases, the three bytes of H3 carry customer traffic, and the J1 byte position moves forward by three bytes. When the pointer value of the combined H1 and H2 bytes remains unchanged, the three bytes of H3 do not carry customer traffic, and the area after the three bytes of H3 begins to carry customer traffic, while the J1 byte position remains unchanged. When the pointer value of the H1 byte and H2 byte combination increases, the three byte positions of H3 and the three byte positions after the H3 byte position do not carry customer services, the byte area after the H3 three byte position starts to carry customer services, and the J1 byte position lags behind by 3 bytes. It can be seen that the function of the pointer value of the H1 byte and H2 byte combination of AU4 is equivalent to the function of the customer-specific content position pointer value (i.e., the second pointer indication value) in the embodiment of the present application, the H3 byte position is equivalent to the - adjustment area, and the first three bytes after the H3 byte position are equivalent to the + adjustment area. In this way, when generating the bearer frame of the VC4 service, the three byte contents of the H1 byte, H2 byte, and H3 of AU4 and the 2349 bytes of VC4 can be copied into the VC4 bearer frame. For example, as shown in Figure 15, the H1 byte and H2 byte are placed in the customer-specific content position pointer value in the overhead area, the three bytes of H3 are placed in the - adjustment area, and all VC4 bytes after H3 in AU4 are placed in the area after the H3 byte position of the VC4 service bearer frame (including the + adjustment area and the fixed bearing area).

[0118] When the bearer frame shown in FIG. 14 or FIG. 15 is mapped to a sub-timeslot for transmission, one such bearer frame may be mapped to 15 or 16 sub-timeslots.

[0119] The bearer frame shown in Figure 14 consists of one S code block, 293 D code blocks, and one T code block. If the overhead is located in the first D code block, the bearer frame can consist of one S code block, 294 D code blocks, and one T code block, as shown in Figure 16. Compared to the bearer frame shown in Figure 14, the bearer frame shown in Figure 16 has an additional D code block, and the overhead bytes are located in the D code block instead of the S code block.

[0120] The bearer frame shown in Figure 15 consists of one S code block, 293 D code blocks, and one T code block. If the overhead is located in the first D code block, the bearer frame can consist of one S code block, 294 D code blocks, and one T code block, as shown in Figure 17. Compared to the bearer frame shown in Figure 15, the bearer frame shown in Figure 17 has an additional D code block, and the overhead bytes are located in the D code block instead of the S code block.

[0121] When the bearer frame shown in FIG. 16 or FIG. 17 is mapped to a sub-time slot for transmission, one such bearer frame may be mapped to 16 sub-time slots.

[0122] It should be noted that in the bearer frames shown in Figures 14 to 17, the -Adjustment Zone and the +Adjustment Zone each comprise three bytes. Therefore, the bearer adjustment zone has an adjustment capacity of three bytes. That is, when the client-specific content location pointer value increases or decreases by one, the bytes carrying the client content can be reduced or increased by three bytes. In other possible implementations, the -Adjustment Zone and the +Adjustment Zone can also consist of other numbers of bytes. By flexibly setting the number of bytes in the -Adjustment Zone and the +Adjustment Zone, the adjustment capacity of the bearer adjustment zone can be flexibly adjusted to accommodate changes in client service speeds.

[0123] When mapping VC4 service bearer frames into sub-timeslots, an appropriate number of idle blocks can be inserted between bearer frames (to meet bearer efficiency, an excessive number should be avoided). Intermediate devices in the network adapt the block rate to the device clock speed by adding and removing idle blocks. For the bearer frames shown in Figures 14 or 15 above, 7 idle blocks can be inserted between every 8 bearer frames. This insertion of idle blocks will reduce the equivalent bearer efficiency of the VC4 service bearer frames (counting the idle blocks as part of the bearer frame), but the reduced bearer efficiency can still achieve the desired 99.2317% bearer efficiency. Similarly, for the bearer frames shown in Figures 16 or 17 above, an appropriate number of idle blocks can be inserted. The specific number of idle blocks inserted is not limited, as long as the bearer efficiency after the insertion of the idle blocks is guaranteed to reach 93.03% (or 93.96%).

[0124] In the embodiments shown in Figures 14 to 17 above, the speed (i.e., rate) of the VC4 service bearer frame and the speed of the sub-timeslot are derived from the same source. The two operating clocks originate from the same clock source and vary in speed synchronously. When the clock drifts faster, the speed of the bearer frame and the speed of the sub-timeslot increase synchronously; when the clock drifts slower, the speed of the bearer frame and the speed of the sub-timeslot decrease synchronously. The speed of the VC4 service is derived from the client service. There is no relationship between the speed of the client service and the speed of the VC4 service bearer frame. The speed deviation between the speed of the client service and the speed of the VC4 service bearer frame needs to be adapted via the bearer adjustment area (-adjustment area and +adjustment area) to accommodate the speed deviation between the two. In some embodiments, an improved scheme for the VC4 service bearer frame is provided to synchronize the speed of the VC4 service bearer frame with the speed of the VC4 client service. That is, the clock of the VC4 service bearer frame and the clock of the VC4 client service originate from the same clock and vary synchronously. In this way, the speed of the VC4 service bearer frame and the speed of the VC4 client service are synchronized, and there is no need to adapt to the speed deviation between the two. In this case, each VC4 service bearer frame can just carry a complete VC4 service. The bearer adjustment area may not be set in the bearer frame, and only a fixed bearer area may be set. The size of the fixed bearer area is equal to the total number of bytes of a complete VC4 service, 2349.

[0125] When no bearer adjustment area is set in the VC4 service bearer frame and one bearer frame carries a complete VC4 service, in some implementations, the VC4 service bearer frame may be as shown in FIG. 18 .

[0126] The bearer frame shown in Figure 18 consists of 1 S code block, 293 D code blocks, and 1 T code block. The overhead area of ​​the bearer frame is located in the D code block, and the bearer area is located in the D code block and the T code block. The bearer area only includes a fixed bearer area of ​​2349 bytes and does not include a bearer adjustment area. When carrying a VC4 service, the VC4 service can be carried in the bearer frame starting from the first byte (or other fixed byte). One bearer frame just carries a complete VC4 service. In each bearer frame, each byte in the VC4 service is in a fixed position in the bearer. For example, in Figure 18, the J1 byte of the VC4 service is always in the first byte position in the fixed bearer area of ​​the bearer frame.

[0127] Since the bearer frame shown in FIG18 does not include a bearer adjustment area, the first pointer indication value and the second pointer indication value may not be required in the overhead field, that is, the specific content location pointer value field is not required, thereby simplifying the structure of the VC4 bearer frame.

[0128] The bearer frame shown in Figure 18 consists of one S code block, 293 D code blocks, and one T code block. If the overhead is located in the first S code block, the bearer frame can consist of one S code block, 292 D code blocks, and one T code block, as shown in Figure 19. Compared to the bearer frame shown in Figure 18, the bearer frame shown in Figure 19 lacks one D code block, and the overhead bytes are moved forward from being located in the D code block to being located in the S code block.

[0129] When the bearer frame shown in FIG. 18 or FIG. 19 is mapped to a sub-time slot for transmission, one such bearer frame may be mapped to 15 or 16 sub-time slots.

[0130] In an exemplary embodiment, when a bearer frame is used to carry one VC4 service, the bearer frame consists of one S code block, X D code blocks, and one T code block, the overhead area is located in the D code block, and the bearer area is located in the D code block and the T code block; or, the bearer frame consists of one S code block, Y D code blocks, and one T code block, the overhead area is located in the S code block, and the bearer area is located in the S code block, the D code block, and the T code block; wherein the bearer area includes a fixed bearer area of ​​2349 bytes, the J1 byte of the VC4 service is located at a fixed position in the fixed bearer area, and X and Y are both integers greater than 1.

[0131] In an exemplary embodiment, X is 293.

[0132] In an exemplary embodiment, Y is 292.

[0133] In an exemplary embodiment, the fixed position includes the first byte.

[0134] In an exemplary embodiment, the overhead area includes multiple bytes; and the overhead information further includes at least one of the following:

[0135] Multiframe indication, used to indicate the sequence relationship of multiple bearer frames in a multiframe group;

[0136] Customer number, used to distinguish different bearer frames carrying different customer services;

[0137] Customer type, used to characterize the service type carried by the bearer frame;

[0138] Cyclic Redundancy Check field.

[0139] The improved scheme for the VC4 service bearer frame structure shown in Figures 18 and 19 synchronizes the speed of the VC4 service bearer frame with the speed of the VC4 client service, omits the content of the bearer adjustment area and the specific content location pointer value in the overhead field of the bearer frame, and simplifies the structure and implementation complexity of the VC4 service bearer frame.

[0140] When the speed of a VC4 service bearer frame is synchronized with the speed of a VC4 client service, the speed of the VC4 service bearer frame will be out of sync with the speed of the service layer sub-timeslot. This will result in a clock offset between the VC4 service bearer frame and the service layer sub-timeslot, and this clock offset needs to be accommodated. Because some IDLE blocks need to be inserted between VC4 service bearer frames to meet the needs of network intermediate equipment for IDLE addition and deletion operations, in some embodiments, the clock offset between the VC4 service bearer frame and the service layer sub-timeslot can be accommodated by inserting IDLE blocks. In a scheme for clock synchronization between VC4 service bearer frames and service layer sub-timeslots, the number of inserted IDLE blocks is fixed, with the number of bearer frames and the number of IDLE blocks being inserted in a fixed ratio (e.g., m:n, where n IDLE blocks are inserted between every m bearer frames, where m and n are positive integers). In an improved scheme for the VC4 service bearer frame structure, because the clock offset between the VC4 service bearer frame and the service layer sub-timeslot exists, the number of inserted IDLE blocks fluctuates, allowing the number of inserted IDLE blocks to be flexibly adjusted based on the speed of the bearer frame and the clock offset between the service layer sub-timeslots. Specifically, when the bearer frame speed decreases compared to the service layer sub-timeslot speed, more IDLE blocks can be inserted. When the bearer frame speed increases compared to the service layer sub-timeslot speed, fewer IDLE blocks can be inserted. This flexible insertion of IDLE blocks ensures that the total block speed (the sum of the number of blocks in the VC4 service bearer frame and the number of IDLE blocks) equals the block speed required by the service layer sub-timeslot speed.

[0141] To accommodate clock skew between VC4 service bearer frames and service layer sub-timeslots, in some embodiments, when a transmitter uses VC4 service bearer frames to carry VC4 services and transmits the bearer frames using sub-timeslots, an exemplary implementation can be shown in Figure 20. In the implementation shown in Figure 20, the transmitter can receive each VC4 service, with each VC4 service bearer frame carrying only one VC4 service. Each byte in the VC4 service is located at a fixed position within the VC4 service bearer frame, thus synchronizing the rate of the VC4 service bearer frame with the rate of the VC4 service. When mapping the VC4 service bearer frames to sub-timeslots, depending on the VC4 service bearer frame speed, if the VC4 service bearer frame and the sub-timeslot are inconsistent, the gap between the two VC4 service bearer frames is uncertain. Therefore, a corresponding number of IDLE blocks are inserted based on the gap between the two VC4 service bearer frames, filling the gap between the two VC4 service bearer frames with the number of IDLE blocks. In one exemplary implementation, a certain number of VC4 bytes can be reserved for reception. Then, while receiving VC4 services, the VC4 services can be encapsulated into VC4 service bearer frames and transmitted in sub-timeslots. This ensures that a continuous stream of VC4 service bearer frame content is transmitted before the VC4 service bearer frame is completed. This ensures that a complete VC4 service bearer frame is transmitted continuously without interruption. After a VC4 service bearer frame is transmitted, an IDLE block is inserted into the idle time segment before the next VC4 service bearer frame is allowed to be transmitted.

[0142] In the SDH system, there's a VC concatenation service that cascades multiple VC services together to achieve a higher-speed VC service. This is typically VC4 concatenation, where N VC4 services are concatenated to form a VC4-N service (N is an integer greater than or equal to 2, such as 2, 3, or 4. VC4-4, with N being 4, is common). For example, a VC4-N service can be formed by concatenating four VC4s, resulting in a VC4-4 service with four times the speed of a single VC4 service. As shown in Figure 21, all bytes in the four VC4 services are aligned, and then the four VC4 services are interleaved on a byte-by-byte basis to form a VC4-4 service. In the SDH system, the VC4-4 service is transmitted as a whole, meaning the four VC4s are transmitted synchronously and in parallel.

[0143] When carrying VC4-N services, one bearer frame can carry one-Nth of a VC4-N service, N bearer frames can carry all of the VC4-N service, or one bearer frame can carry all of the VC4-N service. When one bearer frame carries one-Nth of a VC4-N service, the bearer frame structure can be the same as that of the VC4 service bearer frame.

[0144] In some embodiments, when one bearer frame is used to carry one-Nth of a VC4-N service, and N bearer frames are used to carry all of the services of a VC4-N service, one bearer frame may consist of one S code block, 293 D code blocks, and one T code block. The overhead area of ​​the bearer frame is located in the D code block, and the bearer area is located in the D code block and the T code block. The bearer area only includes the fixed bearer area and does not include the bearer adjustment area. The fixed bearer area includes 2349 bytes. The specific content of the VC4-N service (e.g., N J1 bytes) is located at a fixed position in the N bearer frames. This position can be indicated by an overhead field in the overhead area. In addition, since the bearer area does not include the bearer adjustment area, the overhead area may not include a second pointer indicator value (or it may include a second pointer indicator value, but the second pointer indicator value is only used to indicate the position information of the specific content of the VC4-N service (e.g., N and J1 bytes) in the bearer frame, and is not used to indicate changes in the number of bytes in the bearer adjustment area used to carry customer content).

[0145] Figure 22 is a schematic diagram of a VC service bearer frame carrying one-Nth of a VC4-N service provided by an embodiment of the present application. The bearer frame shown in Figure 22 consists of 1 S code block, 293 D code blocks and 1 T code block. The overhead area (OH area) is located in the first D code block and includes 2 bytes. The bearer area is located in the D code block and the T code block, and the bearer area only includes a fixed bearer area of ​​2349 bytes (the white box area in Figure 22). In Figure 22, each byte in the VC4-N service is carried and stored in a fixed position in the bearer frame. Taking the VC4-4 service as an example, the 4 consecutive J1 bytes can always be located in the 4 byte positions after the overhead byte position, that is, the 3rd, 4th, 5th and 6th byte positions in the first D code block (Figure 22 shows 4 J1 bytes, corresponding to the VC4-4 service. For other VC4-N services, the number of J1 bytes is N, and can always be located in the first N byte positions after the overhead byte position). The bearer frame in Figure 22 has a carrying capacity of 2349 bytes, one-fourth of the N*2349 bytes of VC4-N traffic. Therefore, N consecutive bearer frames are required to carry all VC4-N traffic, i.e., N*2349 bytes. The bearer frame's overhead field can indicate the bearer frame in which the N J1 bytes in the VC4-N are located. For example, the multiframe indicator in the overhead area is used to indicate the order of each frame in a multiframe group, typically represented by a sequence value, such as frame 0, frame 1, frame 2, frame 3, etc. When sequence values ​​appear in the form of 0, 1, 2, 3, 0, 1, 2, 3, 0, 1, 2, 3, etc., it can be agreed that the J1 byte is located in a fixed sequence value, for example, J1 is located in a VC4-N bearer frame with a sequence value of 0. In other implementations, other overhead fields can also be used to indicate the bearer frame in which J1 is located.

[0146] When carrying VC4-N services, the bearer frame shown in Figure 22 can begin carrying the VC4-N service starting with the first J1 byte (or another fixed byte) within the bearer frame. A bearer frame ends after carrying exactly 2349 bytes, and then begins carrying the remaining VC4-N services in the next bearer frame, and so on, until the Nth bearer frame has carried N*2349 bytes of the VC4-N service. In each bearer frame, each byte of the VC4-N service is at a fixed position within the bearer frame. Therefore, the bearer frame does not require a bearer adjustment area, and the overhead field does not require a specific content location pointer value field, thereby simplifying the bearer frame structure.

[0147] The bearer frame shown in Figure 22 consists of one S code block, 293 D code blocks, and one T code block. If the overhead is located in the first S code block, the bearer frame can consist of one S code block, 292 D code blocks, and one T code block, as shown in Figure 23. Compared to the bearer frame shown in Figure 22, the bearer frame shown in Figure 23 lacks one D code block, and the overhead bytes are moved forward from being located in the D code block to being located in the S code block.

[0148] When the bearer frames shown in Figure 22 or Figure 23 are mapped to sub-timeslots for transmission, one such bearer frame can be mapped to 15 or 16 sub-timeslots for transmission. In the case where N such bearer frames carry the complete service of the VC4-N service, the N bearer frames can be mapped to N*15 or N*16 sub-timeslots for transmission.

[0149] The speed of the bearer frame shown in Figure 22 or Figure 23 is synchronized with the speed of the VC4-N client service, but is not synchronized with the clock between the server layer sub-timeslots. To accommodate the deviation, in actual applications, each VC4-N service bearer frame can be mapped to a sub-timeslot for each VC4-N service content received. Depending on the VC4-N bearer frame speed, when the speed of the VC4-N service bearer frame is inconsistent with the speed of the sub-timeslot, the spacing between the two VC4-N service bearer frames is uncertain. Based on the spacing between the two VC4-N service bearer frames, a corresponding number of IDLE code blocks are inserted to fill the gap between the two VC4-N service bearer frames with the IDLE code blocks. In one exemplary implementation, a certain number of VC4-N bytes is reserved for reception. This allows VC4-N services to be received, encapsulated into VC4-N service bearer frames, and transmitted in sub-timeslots. This ensures that a continuous stream of VC4-N service bearer frames is transmitted before the VC4-N service bearer frames are completed. This ensures that a complete VC4-N service bearer frame is transmitted continuously without interruption. After a VC4-N service bearer frame is transmitted, an IDLE block is inserted into the idle time segment before the next VC4-N service bearer frame is allowed to be transmitted.

[0150] It should be noted that, although the bearer adjustment area is not provided in the bearer frame of the VC4-N service shown in FIG22 and FIG23 , in some implementation manners, a bearer area may also be provided in the bearer frame of the VC4-N service. For example, the bearer frame shown in any one of the embodiments of FIG14 to FIG17 may also carry one-Nth of the VC4-N service. N such bearer frames may carry all the services of the VC4-N service.

[0151] The bearer frame provided in the embodiment of the present application can also be used to carry all services of a VC4-N service. The following uses N as 2, 3, or 4 as an example to illustrate the possible frame structure of the VC4-N service bearer frame when carrying all services of the VC4-N service.

[0152] When N is 4 and a bearer frame is used to carry all services of a VC4-4 service, in some implementations, a bearer frame may consist of one S code block, 1174 D code blocks, and one T code block. The bearer frame's overhead area is located in the D code block. The bearer area is located between the D code block and the T code block. The bearer area does not include the bearer adjustment area and only includes a 9396-byte fixed bearer area. The four J1 bytes of the VC4-4 service are located in a fixed position in the fixed bearer area, which may be the first four bytes of the bearer area.

[0153] See Figure 24. The VC-4 service shown in Figure 24 consists of one S code block, 1174 D code blocks, and one T code block. The bearer frame's overhead area (OH area) is located in the first D code block and consists of three bytes. The bearer area is located between the D code block and the T code block. The bearer area does not include the bearer adjustment area and consists only of the 9396-byte fixed bearer area (white box area). The four J1 bytes of the VC4-4 service are located in the first four bytes of the fixed bearer area.

[0154] The bearer frame shown in Figure 24 consists of one S code block, 1174 D code blocks, and one T code block. If the overhead is located in the first S code block, the bearer frame can consist of one S code block, 1173 D code blocks, and one T code block, as shown in Figure 25. Compared to the bearer frame shown in Figure 24, the bearer frame shown in Figure 25 lacks one D code block, and the overhead bytes are moved forward from being located in the D code block to being located in the S code block.

[0155] When the bearer frames shown in Figures 24 or 25 are mapped to sub-timeslots for transmission, one such bearer frame can be mapped to 4*15 or 4*16 sub-timeslots for transmission. For the transmitter, when using the bearer frames shown in Figures 24 or 25 to carry VC4-4 services, it can receive VC4-4 services while encapsulating the VC4-4 services into VC4-4 service bearer frames and simultaneously transmitting the VC4-4 service bearer frames in sub-timeslots. This is achieved by ensuring that a continuous VC4-4 service bearer frame is transmitted before the VC4-4 service bearer frame is completed. This ensures that a complete VC4-4 service bearer frame is continuously transmitted without interruption. After a VC4-4 service bearer frame is transmitted, an IDLE block is inserted into the idle time segment before the next VC4-4 service bearer frame is allowed to be transmitted.

[0156] When N is 3 and a single bearer frame carries all services of a VC4-3 service, in some implementations, a bearer frame may consist of one S code block, 881 D code blocks, and one T code block. The bearer frame's overhead area is located within the D code block. The bearer area is located within the D code block and the T code block. The bearer area does not include the bearer adjustment area and consists only of a 7047-byte fixed bearer area. The three J1 bytes of the VC4-3 service are located in a fixed position in the fixed bearer area, which may be the first three bytes of the bearer area.

[0157] See Figure 26. The VC-3 service shown in Figure 26 consists of one S code block, 881 D code blocks, and one T code block. The overhead area (OH area) of the bearer frame is located in the first D code block and consists of 8 bytes. The bearer area is located between the D code block and the T code block. The bearer area does not include the bearer adjustment area and only includes the 7047-byte fixed bearer area (white box area). The three J1 bytes of the VC4-3 service are located in the first three bytes of the fixed bearer area.

[0158] The bearer frame shown in Figure 26 consists of one S code block, 881 D code blocks, and one T code block. If the overhead is located in the first S code block, the bearer frame can consist of one S code block, 880 D code blocks, and one T code block, as shown in Figure 27. Compared to the bearer frame shown in Figure 26, the bearer frame shown in Figure 27 lacks one D code block, and the overhead bytes are moved forward from being located in the D code block to being located in the S code block.

[0159] When the bearer frames shown in Figures 26 or 27 are mapped to sub-timeslots for transmission, one such bearer frame can be mapped to 3*15 or 3*16 sub-timeslots for transmission. For the transmitter, when using the bearer frames shown in Figures 26 or 27 to carry VC4-3 services, it can receive VC4-3 services while encapsulating the VC4-3 services into VC4-3 service bearer frames and simultaneously transmitting the VC4-3 service bearer frames in sub-timeslots. This is achieved by ensuring that a continuous VC4-3 service bearer frame is transmitted before the VC4-3 service bearer frame is completed. This ensures that a complete VC4-3 service bearer frame is continuously transmitted without interruption. After a VC4-3 service bearer frame is transmitted, an IDLE block is inserted into the idle time segment before the next VC4-3 service bearer frame is allowed to be transmitted.

[0160] When N is 2 and a single bearer frame carries all services of a VC4-2 service, in some implementations, a bearer frame may consist of one S code block, 587 D code blocks, and one T code block. The bearer frame's overhead area is located within the D code block. The bearer area is located within the D code block and the T code block. The bearer area does not include the bearer adjustment area and consists only of a 4698-byte fixed bearer area. The two J1 bytes of the VC4-2 service are located in a fixed position in the fixed bearer area, which may be the first two bytes of the bearer area.

[0161] See Figure 28. The VC-2 service shown in Figure 28 consists of one S code block, 587 D code blocks, and one T code block. The bearer frame's overhead area (OH area) is located in the first D code block and consists of 5 bytes. The bearer area is located between the D code block and the T code block. The bearer area does not include the bearer adjustment area and only includes the 4698-byte fixed bearer area (white box area). The two J1 bytes of the VC4-2 service are located in the first two bytes of the fixed bearer area.

[0162] The bearer frame shown in Figure 28 consists of one S code block, 587 D code blocks, and one T code block. If the overhead is located in the first S code block, the bearer frame can consist of one S code block, 586 D code blocks, and one T code block, as shown in Figure 29. Compared to the bearer frame shown in Figure 28, the bearer frame shown in Figure 29 lacks one D code block, and the overhead bytes are moved forward from being located in the D code block to being located in the S code block.

[0163] When the bearer frames shown in Figures 28 or 29 are mapped to sub-timeslots for transmission, one such bearer frame can be mapped to 2*15 or 2*16 sub-timeslots for transmission. For the transmitter, when using the bearer frames shown in Figures 28 or 29 to carry VC4-2 services, it can receive VC4-2 services while encapsulating the VC4-2 services into VC4-2 service bearer frames and simultaneously transmitting the VC4-2 service bearer frames in sub-timeslots. This is achieved by ensuring that a continuous VC4-2 service bearer frame is transmitted before the VC4-2 service bearer frame is completed. This ensures that a complete VC4-2 service bearer frame is continuously transmitted without interruption. After a VC4-2 service bearer frame is transmitted, an IDLE block is inserted into the idle time segment before the next VC4-2 service bearer frame is allowed to be transmitted.

[0164] It should be noted that the bearer adjustment area is not provided in the bearer frame of the VC4-N service shown in Figures 24 to 29 above. In some implementations, a bearer area can be provided in the VC4-N bearer frame. The number of bytes included in the bearer adjustment area and the number of bytes used to carry customer content in the bearer adjustment area can be determined based on actual bearer requirements. For example, the bearer frame shown in Figure 24 can add a D code block. The overhead area is located in the first D code block and includes 8 bytes. The bearer adjustment area is located in the first six bytes of the first D code block. Of these six bytes, the first three bytes are the - adjustment area, and the last three bytes are the + adjustment area. The bytes following the bearer adjustment area are all fixed bearer areas, totaling 2346 bytes. During normal bearer operation, the - adjustment area does not carry customer content, while the + adjustment area and the 2346-byte fixed bearer area carry customer content. When the VC4-4 service speed is high, the - adjustment area, the + adjustment area, and the 2346-byte fixed bearer area are used to carry customer content. When the VC4-4 service speed is low, the - adjustment area and the + adjustment area do not carry customer content, leaving only the 2346-byte fixed bearer area. The bearer adjustment area can also be configured for VC4-3 and VC4-2 service frames based on the same principle, so detailed examples are not provided here.

[0165] The bearer frames shown in Figures 14 to 19 and 22 to 29 above are exemplary illustrations of the bearer frames for VC services provided in the embodiments of the present application. In other possible implementations, the bearer frames for VC services may also be in formats other than those shown in Figures 14 to 19 and 22 to 29, or in other variations of the bearer frames shown in Figures 14 to 19 and 22 to 29, which are not further illustrated here. Furthermore, the bearer adjustment field in the bearer frames shown in Figures 14 to 17 is illustrated using 6 bytes as an example. In other possible implementations, it may include more bytes, which are not further illustrated here.

[0166] The bearer frame provided in the embodiment of the present application is composed of an S code block, a D code block, and a T code block. The bearer frame includes an overhead area and a bearer area. The overhead area is used to carry overhead information of the VC service, and the bearer area is used to carry customer content of the VC service. The bearer frame is used to be mapped to a sub-timeslot of the service layer for transmission. One bearer frame is used to carry one VC service, which is a VC4 service or a VC4-N service, and N is an integer greater than or equal to 2. In this way, when a VC4 service or VC4-N service is carried in a sub-timeslot based on the FlexE protocol standard, the VC4 service or VC4-N service to be carried can be mapped to the bearer frame, and then the bearer frame can be mapped to the sub-timeslot for transmission. In this way, the carrying of the VC4 service or VC4-N service can be realized, and the carrying requirements for the VC4 service or VC4-N service can be met.

[0167] In an exemplary embodiment, the bearer frame is used to insert idle code blocks between the bearer frames and then mapped to the sub-time slot of the service layer for transmission.

[0168] Based on the bearer frame of the VC service provided in the embodiment of the present application, when carrying a VC4 service or a VC4-N service, for the transmitting end, its bearing method may be as shown in FIG30 .

[0169] Figure 30 is a flow chart of a method for carrying VC services provided by an embodiment of the present application. The carrying method shown in Figure 30 can be executed by a transmitting end and may include the following steps.

[0170] S302: Map the VC service to be carried into a bearer frame, where the VC service is a VC4 service or a VC4-N service.

[0171] The bearer frame here is the bearer frame of the VC service provided in the embodiment of the present application. The specific structure of the bearer frame can be found in the embodiments shown in Figures 6 to 29 above, and will not be described in detail here.

[0172] When carrying VC4 services or VC4-N services, the transmitting end can map the VC4 services or VC4-N services to be carried into the corresponding bearer frames. One VC service can be mapped into one bearer frame.

[0173] For example, when carrying VC4 services, the VC4 services can be mapped to the bearer frames shown in any of the embodiments shown in Figures 14 to 19. When carrying VC4-N services, the VC4-N services can be mapped to the bearer frames shown in Figures 22 or 23. When carrying VC4-4 services, the VC4-4 services can be mapped to the bearer frames shown in Figures 24 or 25. When carrying VC4-3 services, the VC4-3 services can be mapped to the bearer frames shown in Figures 26 or 27. When carrying VC4-2 services, the VC4-2 services can be mapped to the bearer frames shown in Figures 28 or 29.

[0174] S304: Map the bearer frame to the sub-time slot.

[0175] When mapping bearer frames to sub-timeslots, one bearer frame can be mapped to multiple sub-timeslots. For example, for the bearer frames shown in any of the embodiments of Figures 14, 15, 18, and 19, one such bearer frame can be mapped to 15 or 16 sub-timeslots (one bearer frame is used to carry one VC4 service). For the bearer frames shown in Figures 16 or 17, one such bearer frame can be mapped to 16 sub-timeslots (one bearer frame is used to carry one VC4 service). For the bearer frames shown in Figures 22 or 23, one such bearer frame can be mapped to 15 or 16 sub-timeslots (one bearer frame is used to carry 1 / N of a VC4-N service). For the bearer frames shown in Figures 24 or 25, one such bearer frame can be mapped to 4*15 or 4*16 sub-timeslots (one bearer frame is used to carry a complete VC4-4 service). For the bearer frames shown in Figure 26 or Figure 27, one such bearer frame can be mapped to 3*15 or 3*16 sub-timeslots (one bearer frame is used to carry one complete VC4-3 service). For the bearer frames shown in Figure 28 or Figure 29, one such bearer frame can be mapped to 2*15 or 2*16 sub-timeslots (one bearer frame is used to carry one complete VC4-2 service).

[0176] When mapping bearer frames to sub-timeslots, idle blocks can optionally be inserted between bearer frames. This allows intermediate devices in the network to adapt the block rate to the speed of their device clocks by adding or removing idle blocks. The number of idle blocks inserted must meet the bearer frame's load efficiency requirements.

[0177] When inserting idle blocks between bearer frames, you can also insert OAM blocks (abbreviated as O-blocks or O-blocks) based on actual needs. OAM blocks can be used to monitor the service quality of the service layer during bearer frame transmission, such as delay time and bit error status. When OAM monitoring is required, an appropriate number of OAM blocks can be inserted between bearer frames.

[0178] S306: Send the sub-time slot to the receiving end.

[0179] After the bearer frame is mapped into the sub-timeslot, the sub-timeslot can be sent to the receiving end, thereby realizing the bearing and transmission of the VC4 service or VC4-N service.

[0180] Figure 31 is a flow chart of a method for carrying VC services provided by an embodiment of the present application. The carrying method shown in Figure 31 can be executed by a receiving end and may include the following steps.

[0181] S312: Receive the sub-time slot sent by the transmitting end.

[0182] When the transmitting end maps the bearer frame to the sub-timeslot based on the method described in the embodiment shown in FIG. 30 and sends the sub-timeslot to the receiving end, the receiving end can receive the sub-timeslot.

[0183] S314: Parse the sub-timeslot and extract the bearer frame in the sub-timeslot.

[0184] In some embodiments, when the transmitting end maps the bearer frame to the sub-timeslot, the idle code block and / or the OAM code block can be inserted between the bearer frames. Then, when the receiving end parses the sub-timeslot, the OAM code block and the idle code block can be stripped off first, and then the bearer frame can be extracted.

[0185] S316: Parse the S code block, D code block, and T code block in the bearer frame to extract the customer content of the VC service carried by the bearer frame. The VC service is a VC4 service or a VC4-N service.

[0186] After extracting the bearer frame from the sub-timeslot, the receiver can first parse the S and D blocks in the bearer frame to obtain the overhead field in the overhead area of ​​the bearer frame. Based on the indication in the overhead field, the receiver can determine the byte positions of the D and T blocks carrying the customer content and then extract the customer content carried in these byte positions. After parsing the T block, the customer content of the VC4 or VC4-N service carried in the bearer frame can be extracted.

[0187] In some embodiments, when a second pointer indicator value is included in the overhead area of ​​the carrier frame and the second pointer indicator value is effective only in a multi-frame case, after the receiving end parses the overhead area and extracts the second pointer indicator value from the overhead area, it is necessary to use a majority judgment principle to determine the validity of the second pointer indicator value, and when it is determined that the second pointer indicator value is valid, determine the location information of the customer's specific content in the carrier frame and the number of bytes in the carrier adjustment area used to carry the customer content based on the second pointer indicator value. For specific implementation methods, please refer to the embodiments shown in Figures 10 and 11, which will not be explained in detail here.

[0188] Based on the VC bearer frame provided in the embodiment of the present application, when carrying VC4 services or VC4-N services based on the sub-timeslots in the FlexE protocol standard, one VC4 service or VC4-N service to be carried can be mapped into the bearer frame, and then the bearer frame is mapped into the sub-timeslot for transmission. In this way, the carrying of VC4 services or VC4-N services can be realized, meeting the carrying requirements for VC4 services or VC4-N services.

[0189] The foregoing description describes specific embodiments of the present application. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recited in the claims can be performed in an order different from that described in the embodiments and still achieve the desired results. Furthermore, the processes depicted in the accompanying drawings do not necessarily require the specific order shown or the sequential order to achieve the desired results. In certain embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0190] Figure 32 is a schematic diagram of the structure of an electronic device provided by an embodiment of the present application. Please refer to Figure 32. At the hardware level, the electronic device includes a processor, and optionally also includes an internal bus, a network interface, and a memory. Among them, the memory may include a memory, such as a high-speed random access memory (RAM), and may also include a non-volatile memory (non-volatile memory), such as at least one disk storage, etc. Of course, the electronic device may also include hardware required for other services.

[0191] The processor, network interface, and memory can be interconnected via an internal bus, such as an ISA (Industry Standard Architecture) bus, a PCI (Peripheral Component Interconnect) bus, or an EISA (Extended Industry Standard Architecture) bus. These buses can be classified as address buses, data buses, and control buses. For ease of illustration, FIG32 shows only one bidirectional arrow, but this does not imply that there is only one bus or only one type of bus.

[0192] The memory is used to store programs. Specifically, the program may include program code, which includes computer operating instructions. The memory may include internal memory and non-volatile memory, and provides instructions and data to the processor.

[0193] The processor reads the corresponding computer program from the non-volatile memory into the internal memory and then runs it, forming a carrier device for VC services at the logical level. The processor executes the program stored in the memory and is specifically used to perform the following operations:

[0194] Mapping the VC service to be carried into the bearer frame of the VC service, where the VC service is a VC4 service or a VC4-N service;

[0195] Mapping the bearer frame into a sub-time slot;

[0196] The sub-time slot is sent to a receiving end.

[0197] Or, to do the following:

[0198] Receive the sub-time slot sent by the transmitter;

[0199] parsing the sub-timeslot to extract a bearer frame for carrying a VC service in the sub-timeslot;

[0200] The S code block, the D code block and the T code block in the bearer frame are parsed to extract the customer content of the VC service carried by the bearer frame, where the VC service is a VC4 service or a VC4-N service.

[0201] The method performed by the VC service carrier device disclosed in the embodiment shown in FIG32 of the present application can be applied to or implemented by a processor. The processor may be an integrated circuit chip with signal processing capabilities. During implementation, each step of the method can be completed by hardware integrated logic circuits or software instructions in the processor. The processor can be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc.; it can also be a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. The methods, steps, and logic block diagrams disclosed in this application can be implemented or executed. The general-purpose processor can be a microprocessor or any conventional processor. The steps of the method disclosed in this application can be directly implemented and executed by a hardware decoding processor, or by a combination of hardware and software modules in the decoding processor. The software module can be located in a storage medium well-known in the art, such as random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, registers, etc. The storage medium is located in the memory, and the processor reads the information in the memory and, in conjunction with its hardware, completes the steps of the above method.

[0202] The electronic device can also execute the methods of Figures 30 and 31 and implement the functions of the VC service bearer device in the embodiments shown in Figures 30 and 31, which will not be described in detail in this application.

[0203] Of course, in addition to software implementation, the electronic device of this application does not exclude other implementation methods, such as logic devices or a combination of software and hardware, etc. That is to say, the execution subject of the following processing flow is not limited to each logic unit, but can also be hardware or logic devices.

[0204] The present application also provides a computer-readable storage medium storing one or more programs, wherein the one or more programs include instructions. When executed by a portable electronic device including multiple application programs, the instructions enable the portable electronic device to perform the method of the embodiments shown in FIG. 30 and FIG. 31 , and are specifically configured to perform the following operations:

[0205] Mapping the VC service to be carried into the bearer frame of the VC service, where the VC service is a VC4 service or a VC4-N service;

[0206] Mapping the bearer frame into a sub-time slot;

[0207] The sub-time slot is sent to a receiving end.

[0208] Or, to do the following:

[0209] Receive the sub-time slot sent by the transmitter;

[0210] parsing the sub-timeslot to extract a bearer frame for carrying a VC service in the sub-timeslot;

[0211] The S code block, the D code block and the T code block in the bearer frame are parsed to extract the customer content of the VC service carried by the bearer frame, where the VC service is a VC4 service or a VC4-N service.

[0212] FIG33 is a schematic diagram of the structure of a VC service carrying device 330 provided by an embodiment of the present application. Referring to FIG33 , in a software implementation, the VC service carrying device 330 may include: a first mapping module 331, a second mapping module 332, and a sending module 333, wherein:

[0213] A first mapping module 331 maps a VC service to be carried into the bearer frame, wherein the VC service is a VC4 service or a VC4-N service;

[0214] A second mapping module 332 maps the bearer frame to a sub-time slot;

[0215] The sending module 333 sends the sub-time slot to the receiving end.

[0216] In some implementations, the second mapping module 332 maps the bearer frame to the sub-timeslot, including:

[0217] When one of the bearer frames is used to carry one VC4 service, mapping the bearer frame to the 15 sub-timeslots;

[0218] In the case where one of the bearer frames is used to carry one-Nth service of a VC4-N service, mapping the one bearer frame to 15 sub-timeslots;

[0219] In the case where one bearer frame is used to carry all services of one VC4-N service, the one bearer frame is mapped to N*15 sub-time slots.

[0220] The VC service carrying device 330 provided in the present application can also execute the method of FIG30 and realize the functions of the VC service carrying device 330 in the embodiment shown in FIG30 , which will not be described in detail in the present application.

[0221] FIG34 is a schematic diagram of the structure of a VC service carrying device 340 provided by an embodiment of the present application. Referring to FIG34 , in a software implementation, the VC service carrying device 340 may include: a receiving module 341, a first parsing module 342, and a second parsing module 343, wherein:

[0222] The receiving module 341 receives the sub-time slot sent by the transmitting end;

[0223] A first parsing module 342 parses the sub-timeslot to extract a bearer frame for carrying a VC service in the sub-timeslot;

[0224] The second parsing module 343 parses the S code block, the D code block and the T code block in the bearer frame to extract the customer content of the VC service carried by the bearer frame, where the VC service is a VC4 service or a VC4-N service.

[0225] The VC service carrying device 340 provided in this application can also execute the method of Figure 31 and realize the functions of the VC service carrying device 340 in the embodiment shown in Figure 31, which will not be repeated in this application.

[0226] In short, the above description is only a preferred embodiment of the present application and is not intended to limit the scope of protection of the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

[0227] The systems, devices, modules, or units described in the above embodiments may be implemented by computer chips or entities, or by products having certain functions. A typical implementation device is a computer. Specifically, the computer may be, for example, a personal computer, a laptop computer, a cellular phone, a camera phone, a smartphone, a personal digital assistant, a media player, a navigation device, an email device, a game console, a tablet computer, a wearable device, or a combination of any of these devices.

[0228] Computer-readable media includes permanent and non-permanent, removable and non-removable media that can be implemented by any method or technology to store information. The information can be computer-readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, compact disc read-only memory (CD-ROM), digital versatile disc (DVD) or other optical storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device. As defined herein, computer-readable media does not include transitory computer-readable media (transitory media), such as modulated data signals and carrier waves.

[0229] An embodiment of the present application also provides a computer program product, which includes a computer program stored on a non-transitory computer-readable storage medium, and the computer program includes program instructions. When the program instructions are executed by a computer, the computer implements the method as shown in Figures 30 and 31 and can achieve the same technical effect. To avoid repetition, they will not be repeated here.

[0230] It should also be noted that the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, commodity, or apparatus that includes a series of elements includes not only those elements but also other elements not explicitly listed, or includes elements inherent to such process, method, commodity, or apparatus. In the absence of further limitations, an element defined by the phrase "comprises a ..." does not exclude the presence of other identical elements in the process, method, commodity, or apparatus that includes the element.

[0231] The various embodiments in this application are described in a progressive manner. Similar parts between the various embodiments can be referred to in conjunction with each other. Each embodiment focuses on the differences between the other embodiments. In particular, the system embodiment is generally similar to the method embodiment, so the description is relatively simple. For relevant parts, refer to the partial description of the method embodiment.

Claims

1. A bearer frame for a VC service, the bearer frame comprising an S code block, a D code block, and a T code block, and including an overhead area and a bearer area; The overhead area is used to carry overhead information of VC services; The bearer area is used to carry customer content of VC services; The bearer frame is used for mapping to a sub-time slot of a service layer for transmission. One bearer frame is used for carrying one VC service. The VC service is a VC4 service or a VC4-N service, where N is an integer greater than or equal to 2.

2. The bearer frame according to claim 1, wherein the overhead information includes at least one of the following: SDH frame overhead content, used to carry the regenerator section layer and multiplex section layer overhead; The first pointer indication value is used to indicate whether the second pointer indication value has changed abnormally; The second pointer indication value is used to indicate the location information of the client's specific content in the bearer frame; Multiframe indication, used to indicate the sequence relationship of multiple bearer frames in a multiframe group; Customer number, used to distinguish different bearer frames carrying different customer services; Customer type, used to characterize the service type carried by the bearer frame; Cyclic Redundancy Check field.

3. The bearer frame according to claim 2, wherein the bearer area includes a bearer adjustment area and a fixed bearer area, or the bearer area includes the fixed bearer area but does not include the bearer adjustment area; In the case where the bearer area includes a bearer adjustment area, the second pointer indication value is further used to indicate a change in the number of bytes used to bear client content in the bearer adjustment area; In the case that the bearer area does not include the bearer adjustment area, the overhead information does not include the first pointer indication value and the second pointer indication value, and the customer's specific content is in a fixed position in the bearer area.

4. The bearer frame according to claim 3, wherein the second pointer indication value multiplexes the H1 byte and the H2 byte in the AU4 service bearer frame.

5. The bearer frame according to claim 3, wherein when the second pointer indicates a value incremented by one, the position information of the client's specific content in the bearer frame is shifted backward by one unit, and the number of bytes used to carry the client's content in the bearer adjustment area is reduced by one unit; When the second pointer indicates a value minus one, the position information of the client's specific content in the bearer frame moves forward by one unit, and the number of bytes used to carry the client's content in the bearer adjustment area increases by one unit; When the second pointer indication value remains unchanged, the location information of the client's specific content in the bearer frame remains unchanged, and the number of bytes used to carry the client's content in the bearer adjustment area remains unchanged; The unit includes one or more bytes.

6. The bearer frame according to claim 3, wherein the second pointer indicator value comprises W bits, the W bits comprising a first group of bits and a second group of bits, the first group of bits comprising P bits, the second group of bits comprising Q bits, W is an integer greater than or equal to 4, P is an integer greater than or equal to 1 and less than N, and Q is an integer greater than or equal to 1 and less than N; in, When at least half of the bit values ​​in the P bits are flipped, the position information of the client's specific content in the bearer frame is moved backward by one unit, and the number of bytes used to carry the client content in the bearer adjustment area is reduced by one unit; When at least half of the bit values ​​in the Q bits are flipped, the position information of the client's specific content in the bearer frame is moved forward by one unit, and the number of bytes used to carry the client content in the bearer adjustment area is increased by one unit; When the values ​​of the W bits remain unchanged, the location information of the client's specific content in the bearer frame remains unchanged, and the number of bytes used to carry the client's content in the bearer adjustment area remains unchanged; The unit includes one or more bytes.

7. The bearer frame according to claim 5, wherein the bearer adjustment area comprises a first adjustment area and a second adjustment area, and the first adjustment area and the second adjustment area each comprise one or more bytes; in, When the second pointer indication value is used to indicate an increase of one unit, the first adjustment area and the second adjustment area do not carry customer content; In a case where the second pointer indication value is used to indicate a decrease of one unit, both the first adjustment area and the second adjustment area carry customer content; When the value indicated by the second pointer remains unchanged, the first adjustment area does not carry the user content, and the second adjustment area carries the user content.

8. The bearer frame according to claim 7, wherein the first adjustment area multiplexes the H3 byte in the AU4 service bearer frame, and the second adjustment area multiplexes the first byte to the third byte after the H3 byte.

9. According to the bearer frame as described in any one of claims 2 to 8, when the second pointer indication value in L of the consecutive M bearer frames undergoes the same change, the second pointer indication value takes effect in the last frame of the M bearer frames, where M is an integer greater than or equal to 3, and L is an integer greater than or equal to M / 2. 10 . The bearer frame according to claim 9 , wherein when M is equal to 3, L is equal to 2; and when M is equal to 4, L is equal to 3.

11. The bearer frame according to any one of claims 1 to 8, wherein, when one of the bearer frames is used to carry one VC4 service, the bearer frame consists of one S code block, 293 D code blocks, and one T code block, the overhead area is located in the S code block, and the bearer area is located in the S code block, the D code block, and the T code block; or, the bearer frame consists of one S code block, 294 D code blocks, and one T code block, the overhead area is located in the D code block, and the bearer area is located in the D code block and the T code block. in, The bearer area includes a 6-byte bearer adjustment area and a 2346-byte fixed bearer area. The first 3 bytes of the bearer adjustment area are the first adjustment area, and the last 3 bytes are the second adjustment area. The fixed bearer area includes 782 groups of bytes, each group of bytes includes 3 bytes, and the J1 byte of the VC4 service is located at the first position of a group of bytes.

12. The bearer frame according to any one of claims 1 to 8, wherein, when one of the bearer frames is used to carry one VC4 service, the bearer frame comprises one S code block, X D code blocks, and one T code block, the overhead area is located in the D code block, and the bearer area is located in the D code block and the T code block; or, the bearer frame comprises one S code block, Y D code blocks, and one T code block, the overhead area is located in the S code block, and the bearer area is located in the S code block, the D code block, and the T code block. in, The bearer area includes a fixed bearer area of ​​2349 bytes. The J1 byte of the VC4 service is located at a fixed position in the fixed bearer area. Both X and Y are integers greater than 1.

13. The bearer frame as claimed in claim 12, wherein X is 293.

14. The bearer frame as described in claim 12, wherein Y is 292. The bearer frame according to claim 12 , wherein the fixed position includes a first byte.

16. The bearer frame according to claim 12, wherein the overhead area comprises a plurality of bytes; and the overhead information further comprises at least one of the following: Multiframe indication, used to indicate the sequence relationship of multiple bearer frames in a multiframe group; Customer number, used to distinguish different bearer frames carrying different customer services; Customer type, used to characterize the service type carried by the bearer frame; Cyclic Redundancy Check field.

17. The bearer frame according to any one of claims 1 to 8, wherein, when one bearer frame is used to carry one-Nth of a VC4-N service, and N bearer frames are used to carry all services of a VC4-N service, one bearer frame consists of one S code block, 293 D code blocks, and one T code block, the overhead area is located in the D code block, and the bearer area is located in the D code block and the T code block; or, one bearer frame consists of one S code block, 292 D code blocks, and one T code block, the overhead area is located in the S code block, and the bearer area is located in the D code block and the T code block; in, The bearer area includes a fixed bearer area of ​​2349 bytes, and the overhead area is used to indicate the positions of N J1 bytes of the VC4-N service in the N bearer frames.

18. The bearer frame according to any one of claims 1 to 8, wherein, when one bearer frame is used to carry all services of a VC4-4 service, one bearer frame consists of one S code block, 1174 D code blocks, and one T code block, the overhead area is located in the D code block, and the bearer area is located in the D code block and the T code block; or, one bearer frame consists of one S code block, 1173 D code blocks, and one T code block, the overhead area is located in the S code block, and the bearer area is located in the D code block and the T code block; in, The bearer area includes a fixed bearer area of ​​9396 bytes, and the four J1 bytes of the VC4-4 service are located in the first four bytes of the fixed bearer area.

19. The bearer frame according to any one of claims 1 to 8, wherein, when one bearer frame is used to carry all services of a VC4-3 service, one bearer frame consists of one S code block, 881 D code blocks, and one T code block, the overhead area is located in the D code block, and the bearer area is located in the D code block and the T code block; or, one bearer frame consists of one S code block, 880 D code blocks, and one T code block, the overhead area is located in the S code block, and the bearer area is located in the D code block and the T code block; in, The bearer area includes a fixed bearer area of ​​7047 bytes, and the three J1 bytes of the VC4-3 service are located in the first three bytes of the fixed bearer area.

20. The bearer frame according to any one of claims 1 to 8, wherein, when one bearer frame is used to carry all services of a VC4-2 service, one bearer frame consists of one S code block, 587 D code blocks, and one T code block, the overhead area is located in the D code block, and the bearer area is located in the D code block and the T code block; or, one bearer frame consists of one S code block, 586 D code blocks, and one T code block, the overhead area is located in the S code block, and the bearer area is located in the S code block, the D code block, and the T code block. in, The bearer area includes a fixed bearer area of ​​4698 bytes, and the two J1 bytes of the VC4-2 service are located in the first two bytes of the fixed bearer area.

21. The bearer frame according to claim 1, wherein when one of the bearer frames is used to carry one VC4 service or one-Nth of one VC4-N service, the one bearer frame is used to be mapped to 15 or 16 of the sub-timeslots; In the case where one bearer frame is used to carry all services of one VC4-N service, one bearer frame is used to be mapped to N*15 or N*16 sub-timeslots.

22. The bearer frame according to any one of claims 1 to 21, wherein the bearer frame is used to insert idle code blocks between the bearer frames and then map them to the sub-time slot of the service layer for transmission.

23. A method for carrying a VC service based on the bearer frame of the VC service according to any one of claims 1 to 22, applied to a transmitting end, comprising: Mapping a VC service to be carried into the bearer frame, wherein the VC service is a VC4 service or a VC4-N service; Mapping the bearer frame into the sub-time slot; The sub-time slot is sent to a receiving end.

24. The bearer method according to claim 23, wherein mapping the bearer frame to the sub-timeslot comprises: When one of the bearer frames is used to carry one VC4 service, mapping the bearer frame to the 15 sub-timeslots; In the case where one of the bearer frames is used to carry one-Nth service of a VC4-N service, mapping the one bearer frame to 15 sub-timeslots; In the case where one bearer frame is used to carry all services of one VC4-N service, the one bearer frame is mapped to N*15 sub-time slots.

25. A method for carrying a VC service based on the bearer frame of the VC service according to any one of claims 1 to 22, applied to a receiving end, comprising: Receive the sub-time slot sent by the transmitter; Parsing the sub-time slot to extract the bearer frame; The S code block, the D code block and the T code block in the bearer frame are parsed to extract the customer content of the VC service carried by the bearer frame, where the VC service is a VC4 service or a VC4-N service.

26. An electronic device comprising: processor; a memory for storing instructions executable by the processor; The processor is configured to execute the instructions to implement the method according to any one of claims 23 to 25.

27. A computer-readable storage medium, when instructions in the storage medium are executed by a processor of an electronic device, enables the electronic device to perform the method according to any one of claims 23 to 25.

28. A computer program product, comprising a computer program stored on a non-transitory computer-readable storage medium, the computer program comprising program instructions, which, when executed by a computer, enable the computer to implement the method according to any one of claims 23 to 25.

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