WO2005099149A1

WO2005099149A1 - Method for implementing data multiplex and virtual concatenation

Info

Publication number: WO2005099149A1
Application number: PCT/CN2005/000464
Authority: WO
Inventors: Yue Liu; Jingling Liao
Original assignee: Huawei Technologies Co., Ltd.
Priority date: 2004-04-09
Filing date: 2005-04-08
Publication date: 2005-10-20
Also published as: CN1681233B; CN1681233A

Abstract

The present invention discloses a method for implementing data multiplex and virtual concatenation applied in the SDH (Synchronous Digital Hierarchy) network, the method mainly includes the steps of : determining the adaptive capacity's container group containing different lever containers according to the bandwidth of the continuous data bandwidth service to be transmitting; inserting and multiplexing the data of continuous data bandwidth service into the corresponding containers in the group. The method for implementing virtual concatenation is to multiplex the data of continuous data bandwidth service into containers by using the previous method of multiplexing data, and then map the containers into the virtual containers (VCs) by adding virtual concatenation information to the containers, so that it can be transmitted in virtual concatenation manner, the receiver can receive the data of continuous data bandwidth service from the VCs according to the virtual concatenation information. The present invention can map the data flexibly, and can reduce the waste of the bandwidth.

Description

Data multiplexing and virtual cascade implementation method

TECHNICAL FIELD The present invention relates to the field of optical communication technologies, and in particular, to a method for implementing data multiplexing and virtual concatenation in an SDH (Synchronous Digital Series) network.

Background technique

As a basic mode of signal transmission, SDH performs synchronization information transmission, multiplexing, and cross-connection on the channel. SDH signals are transmitted in the form of STM (Synchronous Transmission Module), with standard rate values of 155.520 Mbits / s (STM-1), 622.080 Mbits / s (STM-4), and 2488.320 Mbits / s (STM-16). SDH uses a rectangular block-based frame structure based on a byte structure. It consists of 270 x N columns, 9 rows, and 8 bytes, where N = 1, 4, 16, or 64. The SDH frame structure consists of three areas: information payload (PayLoad), segment overhead (SOH), and management unit pointer (AU PTR). The information payload area contains various information modules to be transmitted and is used for channel performance monitoring, Management and Control Channel Overhead Byte (POH): The SOH area is located in columns 1-9xN, rows 1-3, 5-9, and contains bytes used for network operation, management, and maintenance; AU PTR is a ^ † indicator It is located in 1 ~ 9 x N columns and 4 rows in the frame, and is used to indicate the position of the first byte of the message payload in the frame.

Virtual container VCn (n = ll, 12, 1, 3, 4) is an information structure in SDH. It consists of information payload and channel overhead (P0H). VC11, VC12, VC2, and VC3 are called because of the lower code speed. Is a low-order virtual container, and VC4 is called a high-order virtual container because of its high speed. AU-n is another information structure in SDH. It consists of a high-order virtual container and a corresponding management unit pointer.

In SDH networks, cascading is widely used. Cascading is a data mapping technology implemented on MSTP (Integrated Service Transport Platform), which can combine multiple virtual containers. As a single container that maintains the integrity of the bit sequence, it realizes the transmission of large granular services. The biggest advantage of cascading is that it improves the bandwidth utilization of the transmission system when carrying multiple services (mainly data services).

The concatenation is divided into adjacent cascades and virtual concatenations. Adjacent concatenation is the concatenation of adjacent virtual containers in the same STM-N data frame into the C-4 / 3 / 12-Xc format, as a whole structure. transmission; The advantage of adjacent concatenation is that the services it transmits are a whole, each part of the data does not cause delay, and the signal transmission quality is high.

However, the application of the adjacent cascade method has certain limitations. It requires that all networks and nodes that the service passes support the adjacent cascade method. If it involves a mixed application with the original network equipment, the original equipment may be It cannot support adjacent cascading, so it is impossible to realize full-service transmission. At this time, virtual cascading can be used to complete the transmission of cascaded services.

Virtual concatenation is a method of concatenating virtual containers (which can be the same route or different routes) distributed in different STM-N data frames to form a virtual large-structure VC-4 / 3 / 12-Xv format. For transmission, it separates continuous data bandwidth into separate vx transmissions, and then combines these VCs at the end of the transmission to obtain continuous bandwidth. The adaptation between service bandwidth and SDH virtual container is realized through virtual concatenation, which makes better use of SDH link bandwidth than adjacent concatenation and improves transmission efficiency.

However, the existing technologies for implementing virtual concatenation still have the following disadvantages:

In the existing implementation method of virtual concatenation, only virtual containers of the same rate level can perform virtual concatenation. For example, ITU-T defines VC-4 / 3 / 12-Xv three types of virtual concatenation of single virtual containers. However, there are more and more data services, and the bandwidth is different. Virtual concatenation using a single rate class virtual container is always insufficient in bandwidth utilization. For example, if the data service bandwidth to be transmitted is 160Mbps, such as using VC4 For mapping, because the capacity of the VC4 virtual container is 139.264Mbps, the two VC4s are cascaded together using virtual concatenation technology, and the total capacity is 278.528Mbps, which is obviously wasteful; if VC3 is used for mapping, the If the capacity is 44.736Mbps, four VC3s need to be cascaded together. The total capacity is 178.944Mbps, which wastes 18.944Mbps, which is more efficient than using VC4 virtual concatenation. Further, VC12 can also be used for mapping. Since C12 The virtual container capacity is 2.048Mbps, and 80 VC12s need to be cascaded together to meet the requirements, and only 3.84Mbps is wasted. However, a maximum of 64 VC12 cascades are allowed in the VC12 virtual cascade protocol, so in the above case, VC12 virtual cascade cannot be adopted yet. Obviously, with the current implementation method of virtual concatenation, in many cases, the flexibility of mapping and the utilization of bandwidth are greatly restricted, and need to be further improved. SUMMARY OF THE INVENTION The technical problem to be solved by the present invention is to provide a method for implementing data multiplexing and virtual concatenation with flexible mapping and high bandwidth utilization ratio. By adopting the above method, the flexibility of the mapping body and the bandwidth utilization ratio can be further improved.

To solve the above problems, a data multiplexing method provided by the present invention includes the following steps:

A first determining step: determining a container group including different levels of containers with an adaptive capacity according to a continuous data bandwidth service to be transmitted; a first multiplexing step: inserting and multiplexing data of the continuous data bandwidth service into an office; The corresponding container in the container group.

The first multiplexing step specifically includes:

a) determining the total capacity of the corresponding row of data inserted and multiplexed in the container frame structure of each container group;

b) dividing the data of the continuous data bandwidth service to be transmitted into "" continuous data segments, where the bandwidth of the continuous data segments is adapted to the total capacity;

c) determining the capacity of each row of data inserted and multiplexed in the frame structure of each container; d) dividing the data segment into data sub-segments corresponding to each container, and the bandwidth of the data sub-segment is adapted to the capacity;

e) Interpolating and multiplexing each data sub-segment data into a corresponding guest.

Further, the step e) further includes:

el) determine the number of bytes of each data sub-segment interpolated into the corresponding container data; e2) sequentially multiplex the data of the corresponding number of bytes in each data sub-segment: multiplexed into the corresponding container. In addition, the container includes C2, C3, C4, C11 and C12.

Correspondingly, the present invention provides a method for implementing virtual concatenation, which includes the following steps: a second determining step: determining a container group including different levels of containers with an adaptive capacity according to a continuous data bandwidth service to be transmitted; The second multiplexing step: interleave multiplexing data of the continuous data bandwidth service with corresponding containers in the container group;

A mapping step: mapping the cost of the container plus the virtual concatenation information to a virtual container at a rate class;

Transmitting step: transmitting the virtual container in a virtual concatenated manner;

Receiving step: receiving the data of the continuous data bandwidth service transmitted by the virtual container according to the virtual concatenation information. The second multiplexing step specifically includes:

1) Determine the corresponding total capacity of 4 frames inserted in the container frame structure of each container group;

2) dividing the data of the continuous data bandwidth service to be transmitted into several consecutive data segments, and the bandwidth of the continuous data segment is adapted to the total capacity;

3) determining the passenger number of the corresponding row of data inserted and multiplexed in the middle of each container frame structure;

4) dividing the data segment into data sub-segments corresponding to each container, and the number of sub-segments is adapted to the capacity;

5) Interpolate and multiplex each data sub-segment data into the corresponding container in order.

In addition, the step 5) further includes:

51) Determine the number of bytes of data interleaved and multiplexed into the corresponding container for each data sub-segment;

52) Sequentially multiplex the data of the corresponding number of bytes in each data sub-segment into the phase container.

In addition, the virtual container includes VC2, VC3, VC4, VC11, and VC12. The virtual concatenation information of the VC3, VC4 is transmitted through H4 bytes, and the virtual concatenation information of the VC11, VC12, and VC2 is transmitted through K4 bytes.

Specifically, the virtual concatenation information is a multi-frame number and a virtual container sequence number.

Preferably, the virtual concatenation method is a virtual concatenation of a combination of VC3 and / or VC4 with VC11 and VC12 and / or VC2 virtual containers, and the VC11 / VC12 / VC2 serial number is arranged first in the mapping step. Preferably, the virtual cascading method is a virtual cascade of a combination of VC3 and / or VC4 with VC11 or VC12 and / or VC2 virtual container, and then further expands VC3 and / or VC4 mapped to H4 in VC3 and / or VC2. The byte multiframe indication is used as the virtual concatenation VC11 / VC12 / VC2 virtual concatenation multiframe indication.

Preferably, the virtual concatenation method is a virtual concatenation of a combination of VC3 and VC4 virtual containers. Preferably, the virtual concatenation method is a virtual concatenation of a combination of VC11, VC12, and VC2.

Compared with the prior art, the present invention has the following advantages:

1. According to the bandwidth size of the continuous data bandwidth service, the present invention selects a container of the same level to load, and the data mapping multiplexing is more flexible. If it is applied to the virtual concatenation, it can be selected according to the bandwidth of the continuous data bandwidth service. The rate-level virtual container transmission can improve the flexibility of service mapping in virtual concatenation and enrich the particles of virtual concatenated service mapping.

2. Further, according to the size of the service bandwidth, the present invention selects virtual containers of different rate classes adapted to the corresponding bandwidth to perform virtual concatenation, which can improve the utilization rate of the bandwidth, and avoids the bandwidth caused by the virtual concatenation of the single rate class virtual containers of the prior art. waste.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram of a VC3 / VC4 frame structure in the prior art; FIG. 2 is a schematic diagram of a VC11 / VC12 / VC2 frame structure in the prior art; FIG. 3 is a diagram of multiplexing data into a container in the data multiplexing method of the present invention A flowchart of an alternative embodiment; FIG. 4 is a schematic diagram of data multiplexing in a specific embodiment of the data multiplexing method of the present invention; FIG. 5 is a flowchart of an embodiment of a method for implementing virtual concatenation of the present invention; FIG. 6 is a flowchart of the embodiment of FIG. A flowchart of a preferred embodiment of data multiplexing into a container; FIG. 7 is a schematic diagram of data multiplexing of VC11 and VC12 virtual cascade transmission data according to a specific embodiment of the present invention; Method specific embodiment VC3 and C12 virtual level Schematic diagram of the first line of data reuse for concatenated transmission data;

FIG. 9 is a schematic diagram of the VC3 and VC12 virtual cascade transmission of other row data multiplexing in a specific embodiment of the method for implementing virtual cascading according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention is applied to an SDH network. By improving the method for mapping data of continuous data bandwidth services into virtual containers, a new virtual concatenation method is implemented, which can improve the flexibility of service mapping and enrich the granularity of service mapping. And further improve the utilization rate of bandwidth, so as to achieve the best bandwidth allocation for data transmission services.

In order to better understand the idea of the present invention, first briefly introduce the container / virtual container frame structure and related virtual concatenation technology in the prior art. Referring to FIG. 1 and FIG. 2, FIG. VC11 / VC12 / VC2 frame structure diagram of the virtual container. The frame structure of the virtual container at each rate level is the same as defined in the G.707 protocol. Specifically, the basic structures of VC3 and VC4 are the same. The main difference is the amount of payload. VC4 is 261 columns x 9 rows of payload, VC3 is 85 columns x 9 rows; VC1 K VC12 and VC2 have the same basic structure. It is a 9-row structure, but the payload capacity is different.

In the prior art, in VC3 and VC4, H4 bytes are used to transmit virtual concatenation information. For the meaning of H4 bytes, refer to Table 1.

Table 1

H4 Byte Small Multiframe Number Large Multiframe Number

Bit7 Bit6 Bit5 Bit 4 Bit3 Bit2 Bitl BitO

Small recharge number:

MSB of serial number (bits 4-7) 1 1 1 0 14 n-1 LSB of serial number (bits 0-3) 1 1 1 1 15

MSB for large multiframe number 0 0 0 0 0 n

(bits 4-7)

LSB with large multiframe number 0 0 0 1 1

(bits 0-3) Reserved ("0000") 0 0 1 0 2

Reserved ("0000") 0 0 1 1 3

Reserved ("0000") 0 1 0 0 4

Reserved ("0000") 0 1 0 1 5

Reserved ("0000") 0 1 1 0 6

Reserved ("0000") 0 1 1 1 7

Reserved ("0000") 1 0 0 0 8

Reserved ("0000") 1 0 0 1 9

Reserved ("0000") 1 0 1 0 10

Reserved ("0000") 1 0 1 1 11

Reserved ("0000") 1 1 0 0 12

Reserved ("0000") 1 1 0 1 13 In H4 bytes, there are mainly three meanings: large multiframe number (8bit), 'multiframe number (4bit), and serial number (8bit). One of the large multiframe number and the small multiframe number can be regarded as a multiframe indication. The multiframe indication is the basis for delay alignment of the receiving end. The size of the multiframe capacity directly affects the ability to transmit data delay. Therefore, the ITU-T defines a 12-bit multiframe indicator, which is transmitted in two segments, which are a large multiframe number and a small multiframe number. The lower 4bit of the H4 word is the small multiframe number. When the value of the lower 4bit is 0 and 1, the corresponding high 4bit is the MSB (high 4bit) and LSB (low 4bit) of the large multiframe number. The multi-frame in the virtual concatenation refers to the frame marker that can be sent, which is used to indicate the number of frames that are being sent. At the same time, the frames sent by J should have the same multi-frame number.

In VC12 and VC11, the virtual concatenation information is represented by bit 6 of K4 bytes, as shown in Table 2:

Table 2

As can be seen from the frame structure of VC12 / VC11 in Figure 2, a complete VC11 / VC12 frame is 500us, of which K4 byte is an overhead byte. Because VC11 / VC12 has too few overhead bytes, each overhead byte has several meanings. It is related to the virtual concatenation. Only bit 6 in the K4 byte is shown in Table 2. As shown in Table 2, there are 32 consecutive 32 frames. Bit 6 of the K4 byte constitutes a complete virtual concatenation information, which is used to indicate the sequence number and the multi-frame number, of which bitl-bit5 Is the multi-frame number, bit6 ~ bitll is the serial number, the function and meaning of the multi-frame number and the serial number are the same as those in the H4 byte.

In the SDH network, for continuous bandwidth services, the data multiplexing technology currently used can be selected to load a single information container at an appropriate level of capacity according to the bandwidth of the service. For example, for a branch signal of 2.048 Mbit / s, it can be selected. The information container C12 is loaded. For the data of 34.368Mbit / s and 44.736Mbit / s, the information container C3 can be loaded, and multiple low-order containers C11 or C12 can also be loaded, and further mapped and multiplexed to the high-order container for transmission. In the prior art, a single container is used to load data of a continuous data bandwidth service, the service mapping is monotonous, and data multiplexing cannot fully utilize bandwidth resources. Therefore, the present invention proposes a new data multiplexing method, which mainly uses the following two methods: Steps:

In the first step, a container group including different levels of containers is determined according to the bandwidth of the continuous data bandwidth service to be transmitted;

Because the loading capacity of each container in the SDH network is different, if a single container is used to load the data of the continuous data bandwidth service, there may be a waste of bandwidth. For example, the continuous data bandwidth of the service is 100 Mbps. If C4 is used to load the service data, due to the C4 container ’s If the capacity is 139.264 Mbps, 39.264 Mbps of bandwidth resources will be wasted, and if different levels of containers are used for mixed loading, the bandwidth can be wasted P by arbitrarily combining containers. Therefore, in the data multiplexing method of the present invention, according to The bandwidth of the continuous service is determined to include container groups of different levels of containers. The total capacity of the container group should be adapted to the bandwidth of the continuous service to load the service data. For example, for a service with a continuous data bandwidth of 100 Mbps, two containers C3 can be selected. Add 5 C12 containers to load, because the capacity of C3 container is about 45Mbps, the capacity of C12 container is about 2Mbps, so the capacity of 2 C3 containers, and the capacity of 5 C12 containers is about 100Mbps, so it will not be wasted bandwidth.

In the second step, the data of the continuous data bandwidth service is interleaved and multiplexed into the corresponding containers in the container group.

The above first step determines the corresponding container for loading data according to the bandwidth of the continuous data bandwidth service. In this step, the above-mentioned continuous bandwidth service data can be multiplexed into the corresponding container using the interleaved multiplexing method, because the total capacity of the container group Adapt to service bandwidth, can make bandwidth Waste is further reduced. Various methods can be used to specifically multiplex data into each container in the container group. The following is a description of a preferred embodiment. Specifically, considering that the frame structure of various containers in the SDH network is mostly 9 The block-like frame structure of a line may adopt a line multiplexing method. Referring to FIG. 3, a preferred embodiment uses the following steps to process data:

At step s31, determine the total capacity of the corresponding row of data inserted and multiplexed in the container frame structure of each container group;

In step s32, the data of the continuous data bandwidth service to be transmitted is divided into several continuous data segments, and the continuous data segment bandwidth is adapted to the total capacity;

In step s33, determine the capacity of the corresponding row of data inserted and multiplexed in the middle of each container frame structure;

In step s34, the data segment is divided into data sub-segments corresponding to each container, and the bandwidth of the data sub-segment is adapted to the capacity;

At step s35, the data of each data sub-segment is interleaved and multiplexed into a corresponding container. Complete the data reuse process.

The above data segment bandwidth may be the sum of the data capacity of one line in each virtual container frame structure of the virtual concatenation transmission, or may be the sum of the data capacity of multiple lines. Similarly, the data subband bandwidth may be the corresponding virtual container frame The data capacity of one line in the structure may also be the data capacity of multiple lines. In addition, the data sub-segment may be a continuous data sub-segment of continuous bandwidth in the data segment, or it may be a logical data sub-segment (that is, a distribution Non-contiguous data sub-segments in the data segment), the data sub-segments can be multiplexed into corresponding containers in step s35 in a variety of ways, for example, continuous data sub-segments can be directly multiplexed into entire segments in sequence. In the corresponding row of the corresponding container, the number of bytes of data in each data sub-segment can be further interpolated into the corresponding container, and then the corresponding number of bytes in each data sub-segment can be interleaved and multiplexed into the corresponding In the container.

The following is an example for illustration. Referring to FIG. 4, a continuous data bandwidth service with a bandwidth of 185 Mbps is used for description. First, a container group for loading data is determined. As an optional example, for example, a container group C3 and a container group C4 are selected. Loading, since C4 and C3 are both 9-line frame structures, in one line, C4 has 260 payloads and C3 has 84. It can divide the 185Mbps bandwidth into 344 (260 + 84) byte payload data segments , Of course After that, the data segment is further divided into a data sub-segment with a payload of 260 bytes and a data sub-segment of 84 payloads. The data sub-segment may be a continuous data sub-segment, for example, in a 344-byte payload. The first 260 consecutive byte payloads are used as the data sub-segment corresponding to the C4 container, and the last 84 consecutive byte payloads are used as the data sub-segment corresponding to the C3 container. When multiplexed, the 260 bytes corresponding to the C4 container are directly used at one time. The payload is multiplexed into the C4 container, while the 84-byte payload corresponding to the C3 container is multiplexed directly into the C3 container at one time.

As another preferred method that can be implemented, the data sub-segments corresponding to each container may be non-contiguous data sub-segments, the number of bytes of each data sub-segment multiplexed into the corresponding container can be further divided, and then the corresponding bytes in the data sub-segment The number of data is interleaved and multiplexed into the corresponding container. For example, considering the relationship between the capacity of the C4 container and the C3 container is 3 times + 8, for each 3 data multiplexed into C4, one data is multiplexed into C3, to C3— After the lines are multiplexed, C4 multiplexes 252 data. At this time, 8 data are continuously multiplexed into C4 to complete one line of multiplexing, and the multiplexing of the next line is continued. Each line is performed in the same way until All data is reused. For actual business, it is obviously impossible to have a completely matched container, that is, the total capacity of the selected container group will be appropriately larger than the actual continuous data bandwidth. In this way, padding bytes can be added to the remaining part of the container. The key is not detailed here.

The method for implementing the virtual concatenation of the present invention is described below.

In the prior art, a single virtual container has a problem of bandwidth waste due to virtual concatenated transmission. To overcome this problem, the above data multiplexing method can be used to load data in different containers and then transmitted in a virtual concatenated manner. This can reduce the bandwidth. Waste, referring to FIG. 5, the method for implementing virtual concatenated transmission of the present invention is described in detail below. Specifically, the method mainly includes the following steps:

In step s51, a container group including different levels of containers with an adaptive capacity is determined according to the bandwidth of the continuous data bandwidth service to be transmitted;

In step s52: data of a continuous data bandwidth service is interleaved and multiplexed into a corresponding container in the container group;

At step s53: mapping the cost of the container plus the virtual concatenation information to a virtual container of a corresponding rate level; At step s54: transmitting the virtual container in a virtual concatenation manner; at step s55: receiving the data of the continuous data bandwidth service transmitted by the virtual container according to the virtual concatenation information receiving end.

The above virtual concatenation implementation method uses the data multiplexing method (ie, steps s51, s52) of the present invention, which is the same as the data multiplexing method. Specifically, when data is multiplexed into each container for loading, for various container combinations, It is better to use a row multiplexing method, which is convenient for demultiplexing data when receiving. Specifically, to implement step s52, referring to FIG. 6, the following optimized method is adopted:

In step S521: determine the total capacity of the corresponding row of the multiplexed data inserted in the container frame structure of each container group;

In step s522, the data of the continuous data bandwidth service to be transmitted is divided into several continuous data segments, and the continuous data segment bandwidth is adapted to the total capacity;

In step s523: determine the capacity of the corresponding row of the data field data interpolated and multiplexed between each container frame structure;

At step s524: dividing the data segment into data sub-segments corresponding to each container, and the bandwidth of the data sub-segment is adapted to the capacity;

In step s525: the data of each data sub-segment is interleaved and multiplexed into a corresponding container.

Since SDH is processed in units of bytes, for step s525, the number of bytes of data in each data sub-segment can be further interleaved and multiplexed into the corresponding container; then the corresponding number of bytes in each data sub-segment is sequentially Data is multiplexed into corresponding containers.

In the following, different virtual container combinations are used to illustrate in detail.

1. Implementation of VC3 / VC4 virtual cascade with the same structure Refer to Figure 7. The mixed virtual cascade of VC3 and VC4 is basically similar to the current single container virtual cascade. First determine the VC3 and VC4 time slots for virtual concatenation transmission, and then the network manager allocates the sequence numbers that should be in each time slot, and performs data mapping in order according to the size of the sequence number. No data mapping is performed for the time slots that are not allocated. The information of the virtual concatenation, the multiframe number and sequence number, are included in the overhead byte H4 of each VC4 and VC3. In the process of data mapping and demapping, C3 and C4 are multiplexed first, then C3 plus overhead mapping becomes VC3, C4 plus overhead mapping becomes VC4, and the next mapping is performed according to the mapping structure defined by G.707.

2, VC11 / VC12 virtual cascade implementation of the same structure

The basic structure of mixed VC12 and VC11 virtual cascade transmission is similar to the current single container virtual cascade transmission. First, determine the VC12 and VC11 time slots for virtual cascade transmission, and then the network management assigns the sequence numbers that should be in each time slot. Data mapping is performed in order according to the size of the sequence number, and data mapping is not performed for the unassigned time slots. The information of the virtual concatenation—multiframe number and sequence number are included in the overhead byte K4 of each VC11 and VC12.

As with the mixed data multiplexing of C3 and C4, C11 and C12 are preferably multiplexed line by line. Except for line 9, each line of C12 is 1 byte more than C11, so when multiplexing the first 8 lines There will be two consecutive bytes of data multiplexed into C12; and in line 9, since C12 has one more padding byte, the payloads of C12 and C11 are the same, both are 2 bytes, so the data is multiplexed into C3 and C4 are the same. Refer to Figure 7 for the data multiplexing process.

3. Implementation of virtual cascade with different structures

The implementation of virtual cascade with different structures is quite different from the existing virtual cascade implementation. It mainly refers to the different structural combinations of VC3 and / or VC4 and VC11 and / or VC12 and / or VC2. The following uses VC3 and VC12 virtual stages As an example, the implementation method is divided into a sending end and a receiving end for explanation.

Sender:

1) Select a container according to the bandwidth size of the continuous data bandwidth service that needs to be virtual concatenated. Taking the 100M service as an example, the container size of C3 is about 45M, and the container size of C12 is about 2M. In this way, two C3 containers and five C12 containers can be selected;

2) Number the selected virtual container, that is, determine the size and sequence of the SQ (serial number). Considering that the range of VC12 / VC11's serial number is small, the serial number is arranged from VC11 / VC12 and then VC3 / VC4, for example, 1), the serial numbers of 5 C12 containers are 0 ~ 4, 2 C3 containers The serial number is 5 ~ 6; 3) The data of the continuous data bandwidth service are respectively mapped into the corresponding virtual containers according to the serial number and the multi-frame number.

Because the first and last rows of C12 only have 2 payloads, and the other rows are all 4, the data reuse method of the first and last rows is the same as shown in Figure 8, and the data reuse method of the middle 7 rows is the same. See Figure 9. In the present invention, for the virtual container of the mixed virtual concatenation, in the arrangement of the multiframe number, for every 125us of the VC3 structure, the multiframe count of H4 bytes is incremented by one; and for VC12, the multiframe number is determined by the second stage.

According to the definition of the multiframe number of VC3, we also refer to the two-level multiframe of VC12 as the small multiframe (MF1) and the large multiframe (MF2). In the first stage, the lowest multiframe number (ie, MF1) is determined according to the lower 2 bits of the H4 byte (multiframe indication byte) of VC3 mapped into VC12. In the upper-level mapping of VC12 / VC11, first map into TUG-2-add pointer indication on the basis of VC12, and then map into VC3 or TUG3 and then VC4. In this way, if the mapping of VC12 / VC11 is selected, the superior VC3 or VC4 cannot be virtual concatenated, so their overhead H4 bytes are no longer the content defined by the virtual concatenation, but the VC12 / VC11. The multiframe indication byte is not a multiframe indication in the virtual concatenation, but a 500us multiframe indication. At this time, only the bit0 and bitl of the H4 byte are significant. When it is 00, it means that the first subframe in the 500us multiframe is the first 125us, and when it is 01, it means that the second subframe in the 500us multiframe is the first. Two 125us, when it is 10, it means the third 125us, and at 11 it means 1254 125us. In fact, this definition is basically the same as the multiframe indication use in virtual concatenation. Therefore, when the present invention implements hybrid virtual concatenation, VC3 (or VC4) is extended, which mainly depends on whether the further mapping of VC12 is mapped into VC3 or VC4. VC12 is mapped into VC3 in this embodiment) The H4 byte multiframe indication byte is used as the small multiframe of VC11 / VC12 (the concept of small multiframe was not originally included in the VC11 / VC12 virtual cascade definition, only FrameCounter is a multiframe Count :), used to implement virtual concatenated multiframe indication. Because the virtual concatenation needs to receive the multi-frame number before starting to demap the data, the virtual concatenation in VC11 / VC12 alone will have a large waiting time, resulting in a large delay in the data transmission process. And if it also has a multi-frame number every 125us (that is, the copy instruction of the extended H4 byte of the present invention), then VC3 / VC4—Like, wait for 125us for demapping, greatly reducing processing delay. In addition, during the demapping, the frame number of each specific frame in the multi-frame is further determined, that is, the second-level multi-frame number (that is, the large multi-frame number) is determined according to the multi-frame number of the K4 byte. This is the same as the current multi-frame number. The definition of virtual concatenation is the same and will not be described in detail.

At the receiving end: First, determine the delay difference according to the multiframe number, and align the virtual containers of different structures in the same virtual concatenation group. The virtual containers may be the virtual concatenation of VC3 / VC4 and VC11VC12. It may be the virtual concatenation of VC3, VC4 and VC11 / VC12. Further, the virtual containers in the same virtual concatenated group are sorted according to the sequence numbers, and then the data is recovered, and corresponding multiframe numbers, sequence numbers, and delays out of range alarms are generated.

The above only describes the present invention with preferred embodiments, which does not limit the scope of the rights of the present invention. Therefore, without departing from the idea of the present invention, any equivalent changes made using the description and drawings of the present invention are equivalent. The same is included in the scope of claims of the present invention.

Claims

Rights request

1. A data multiplexing method, which is applied to a synchronous digital series network and is characterized in that it includes the following steps:

Step a: Determine a container group including different levels of containers with an adaptive capacity according to a bandwidth of a continuous data bandwidth service to be transmitted;

Step b: Interleave multiplexing data of the continuous data bandwidth service into corresponding containers in the container group.

2. The data multiplexing method according to claim 1, wherein the step b specifically comprises:

bl) determining the total capacity of the corresponding row of data inserted and multiplexed in the container frame structure of each container group;

b2) dividing the data of the continuous data bandwidth service to be transmitted into several continuous data segments, and the continuous data segment bandwidth is adapted to the total capacity;

b3) determining the capacity of a corresponding row of data inserted and multiplexed in the frame structure of each container; b4) dividing the data segment into data sub-segments corresponding to each container, and the bandwidth of the data sub-segment is adapted to the capacity;

b5) Interpolating and multiplexing each data sub-segment data into a corresponding container.

3. The data multiplexing method according to claim 2, wherein the step b5 further comprises:

b51) determining the number of bytes of the data of each data sub-segment multiplexed into the corresponding container; b52) sequentially interleaving the data of the corresponding number of bytes in each data sub-segment into the corresponding container.

4. The data multiplexing method according to any one of claims 1, 2 or 3, wherein the container comprises C2, C3, C4, C11 and C12.

5. A method for implementing virtual concatenation, which is applied to a synchronous digital series network, and is characterized by including the following steps:

Step 1: Determine a container group including different levels of containers with an adaptive capacity according to the bandwidth of the continuous data bandwidth service to be transmitted;

Step 2: interleave multiplexing data of the continuous data bandwidth service into the container group Corresponding container in

Step 3: Map the container plus the overhead including the virtual concatenation information to a virtual container of a corresponding rate level;

Step 4: transmitting the virtual container in a virtual concatenated manner;

Step 5: Receive the data of the continuous data bandwidth service transmitted by the virtual container according to the virtual concatenation information receiving end.

6. The method for implementing virtual concatenation according to claim 5, wherein the step 2 specifically comprises:

21) Determine the total capacity of the corresponding row of data inserted and multiplexed in the container frame structure of each container group;

22) dividing the data of the continuous data bandwidth service to be transmitted into several continuous data segments, and the continuous data segment bandwidth is adapted to the total capacity;

23) determining the capacity of the corresponding row of data inserted and multiplexed in the frame structure of each container; 24) dividing the data segment into data sub-segments corresponding to each container, and the bandwidth of the data sub-segment is adapted to the capacity;

25) Interpolating and multiplexing each data sub-segment data into a corresponding container in order.

7. The method for implementing virtual concatenation according to claim 6, wherein the step 25) further comprises:

251) Determine the number of bytes of data multiplexed into the corresponding container between each data sub-segment; 252) Sequentially multiplex the data of the corresponding byte number in each data sub-segment into the corresponding container.

8. The method for implementing virtual concatenation according to claim 5, wherein the virtual container comprises VC2, VC3, VC4, VC11, and VC12, and the virtual concatenation information of the VC3 and VC4 is transmitted through H4 bytes. The virtual concatenation information of VC11, VC12 and VC2 is transmitted through K4 bytes.

9. The method for implementing virtual concatenation according to claim 8, wherein the virtual concatenation information is a multi-frame number and a virtual container sequence number.

10. The method for implementing virtual concatenation according to any one of claims 5-9, wherein the virtual concatenation mode is VC3 and / or VC4 and VC11 and / or VC12 and / or VC2 The virtual concatenation of the virtual container combination arranges the VC11 / VC12 / VC2 serial numbers first in the mapping step.

11. The method for implementing virtual concatenation according to claim 10, wherein the virtual concatenation method is a virtual concatenation of a combination of VC3 and / or VC4 and VC11 and / or VC12 and / or VC2 virtual containers, then The H4 byte multiframe indication in VC3 and / or VC4 mapped into VC11 / VC12 / VC2 is further extended as the virtual concatenated VC11 / VC12 / VC2 virtual concatenated multiframe indication.

12. The method for implementing virtual concatenation according to any one of claims 5 to 9, wherein the virtual concatenation method is a virtual concatenation of a combination of VC3 and VC4 virtual containers.

13. The method for implementing virtual concatenation according to any one of claims 5-9, wherein the virtual concatenation method is a virtual concatenation of any combination of virtual containers of VC11, VC12, and VC2.