JP4177169B2 - Data transmission method and apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a data transmission method and apparatus, and more particularly to a data transmission method and apparatus for a system that transmits a plurality of transmission frames having an overhead part and a payload part in time series.
[0002]
[Prior art]
In a transmission apparatus, there is a method in which time division multiplexing (TDM) data is mounted and transmitted in a predetermined slot of a payload portion in a transmission frame, or TDM data is packetized and mapped to an arbitrary position. Be taken. In the former case, the slot (position) to which data is mapped has meaning, and what (which channel) information is determined by the position. In the latter case, the contents of the data to be mapped are meaningful, and usually the header (data identification flag) indicates what each data is.
[0003]
Also, if you want to handle such TDM data and packet data at the same time, it is necessary to match the data format to either one. Usually, the TDM data is grouped for each user (channel) and a header is added. The packet data is unified into packet data. Also, there are ATM packets, Ether packets, etc. in the packet, and the form varies depending on the type. When several types of packets are mixed, the packets are reassembled and unified into a certain packet for data transmission. There is a need to do. For that purpose, it is necessary to have a function for processing in stages for each packet type in each device for transmission and reception, and packet data is repeatedly disassembled and assembled, which complicates the configuration of the transmission device. .
[0004]
Thus, conventionally, in order to map data of different formats to the same transmission frame, it is necessary to unify packets by performing complicated data conversion processing step by step. For this purpose, packet disassembly / assembly, etc. The complicated processing in the transmission apparatus is required. Also, by packetizing, it is necessary to add a header and an extra data area is required, so that the transmission efficiency has deteriorated.
[0005]
Under such circumstances, conventionally, a network architecture that carries digital information in a unique format or format by each container constituting a multiplexed frame is known (Patent Document 1, specification page 11, lines 8-9). Here, all domain nodes can load information into the partition allocated in the container (page 13 line 5-6, FIG. 2). Each container is provided for a specific node, and when the container reaches the destination node, the node unloads the payload loaded by another node (lines 13 to 11 on page 13). The container for node A has partitions for nodes B, C, D, and E. For example, the partition for node B in the container for node A is exclusively used for traffic from node B to node A. This is the bandwidth provided (page 13, line 13-18, FIG. 2).
[0006]
[Patent Document 1]
JP-T-2001-503949 (abstract, specification, FIG. 2).
[0007]
[Problems to be solved by the invention]
However, when the above data is mounted on each container on the transmission frame and transmitted, overhead processing for container identification is required and the data format is unified for each container (or partition). / Complex processing to unpack is required.
[0008]
The present invention has been made in view of the above problems of the prior art, and an object of the present invention is to provide a data transmission method and apparatus capable of efficiently transmitting various types of data with a simple configuration and processing. is there.
[0009]
[Means for Solving the Problems]
  The above problem is solved by the configuration of FIG. That is, the data transmission method of the present invention (1) is a data transmission method of a system for transmitting a plurality of transmission frames having an overhead part and a payload part in time series,Certain transmissionIn the overhead part of the frame, Data identification information for identifying different types of data to be mapped to the payload portion of the next transmission frameWhen, The data corresponding to this identification information isNextTransmissionflameofpayloadAnd location information when mappingpowered byAs a transmission frame next to the certain transmission frame, the data in the form indicated by the data identification information is transferred to the position indicated by the position information.It is installed and transmitted.
[0010]
  According to the present invention (1), the previous frame(Equivalent to a certain transmission frame)Data identification information and next frame that can identify what type of data (TDM data / packet data, etc.) the data is in the overhead part of i(Equivalent to the next transmission frame j)With a simple method that simply mounts information representing the write area on the payload, various types of data on the same transmission frame can be easily mapped / decoded without the need for complicated overhead processing. Mapping becomes possible. Although FIG. 1 shows a case where only packet data is mounted, the entire payload portion can be divided into a plurality of areas, and TDM data, packet data, cell data, etc. can be mounted on these areas.
[0011]
  The data transmission method of the present invention (2)The heterogeneous data isPacket data and / or cell dataThe data identification information and the corresponding position information are the overhead of the certain transmission frame.PartAre mounted on the board.
[0012]
The payload part of the present invention (2) is basically all for mounting TDM data, but packet data and / or cell data can be transmitted by setting an arbitrary area on it. . Therefore, for TDM data, it is not necessary to provide data identification information and area designation information in the overhead part, so that unused areas on the overhead part can be used effectively.
[0013]
  Further, the data transmission method of the present invention (3) includes an overhead unit.WhenA data transmission method of a system for transmitting a plurality of transmission frames having a payload portion in time series,Certain transmissionIn the overhead part of the frameInformation indicating the mounting pattern of a plurality of heterogeneous data to be mapped to the payload portion of the next transmission framepowered byAs a transmission frame next to the certain transmission frame, the plurality of different forms are provided at the positions defined by the mounting pattern.DataRespectivelyIt is installed and transmitted.
[0014]
In the present invention (3), the type and position of various data mounted on the payload of the next frame are specified by information representing a simple heterogeneous data mounting pattern. For example, when pattern information indicating that TDM data is M bytes (or slots) and packet data is N bytes (or slots) is written in the overhead portion of the previous frame, the TDM data is first started from the beginning of the payload portion of the next frame. Is loaded in order with a repeating pattern of M bytes and then packet data of N bytes. Therefore, the unused area on the overhead portion can be used more effectively.
[0015]
  The data transmission device of the present invention (4) is an overhead unit.WhenA data transmission device of a system for transmitting a plurality of transmission frames having a payload portion in time series,From an external deviceA receiver for receiving and terminating time division multiplexed data and packet data and / or cell data;Received by the receiverBuffer each received data individuallyRuA buffer section;Data identification information of packet data and / or cell data mapped to the payload portion of the next transmission frame, and data corresponding to this identification information are transmitted to the overhead portion of a certain transmission frame transmitted by the local station, and An overhead insertion part for inserting position information when mapping to the payload part;Your station sendsSaidNextTransmissionFor the payload part of the frame,The packet data and / or cell data stored in the buffer unit are mapped in accordance with the data identification information inserted by the overhead insertion unit and the corresponding position information.And a data mapping unit.
[0016]
  In the present invention (5), in the present invention (4), a flow rate measuring unit for measuring the flow rate of each received data is provided, and the data mapping unit is provided in the payload portion according to the measured flow rate.mappingDoPacket data and / or cellThe data size is changed. Therefore, the bandwidth of the payload portion can be used efficiently according to the flow rate of the received data.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described in detail with reference to the accompanying drawings. Note that the same reference numerals denote the same or corresponding parts throughout the drawings.
[0018]
2 and 3 are diagrams (1) and (2) showing the configuration of the data transmission system according to the embodiment, and show a case where TDM data and packet data are transmitted in the same transmission frame. FIG. 2 shows the configuration of the data transmission side. In the figure, 10A is a TDM communication apparatus that transmits TDM data, 20A is a packet communication apparatus that transmits packet data, 100A is a transmission apparatus that accommodates communication apparatuses 10A and 20A, 30 is a transmission unit thereof, and 31 is a terminal that terminates TDM communication. TDM interface unit (TDMIF) 32, a flow rate monitoring unit 32 for monitoring the flow rate of received TDM data, 33 a FIFO buffer (FIFO) for temporarily buffering TDM data, and 34 a TDM data write control unit (WC) ), 35 is a TDM data read control unit (RC), 41 is a packet interface unit (PCDIF) that terminates packet communication, 42 is a flow rate monitoring unit that monitors the flow rate of received packet data, and 43 temporarily stores packet data. FIFO buffer to be buffered (FIFO) 44 is packet data The write control unit (WC), 45 is a packet data read control unit (RC), and 46 is a distribution of data (data) mounted in the transmission frame (payload) of the own station based on the flow rate monitoring results of TDM data and packet data. A flow control unit for controlling the size etc., 51 a data mapping unit for mapping TDM data and packet data to each corresponding area according to the size information of the flow control unit 46, and 52 for transmitting the mapped TDM data and packet data to the transmission frame Multiplexer (MUX) 53 for multiplexing in the payload portion of the packet, 53 is an overhead for inserting predetermined overhead information (including packet data identification information and offset information indicating the mounting area on the payload) into the overhead portion of the transmission frame An insertion unit 54 is an E / O unit that converts an electrical signal (transmission frame) into an optical signal, 2 0 is an optical transmission line consisting of optical fiber.
[0019]
FIG. 3 shows the configuration of the data receiving side. In the figure, 100B is a transmission device opposite to the transmission device 100A, 60 is a receiving unit thereof, 61 is a 0 / E unit that converts an optical signal into an electric signal (received frame), and 62 is an overhead information (from overhead portion of the received frame). An overhead extraction unit for extracting packet data identification information and offset information), 63 is a separation unit (DMUX) for separating TDM data and packet data in a received frame (payload portion) based on the extracted offset information, 64 is a data demapping unit for demapping TDM data and packet data from each separated data block, 65 is a TDM interface unit (TDMIF) for terminating TDM communication, and 66 is a packet interface unit for terminating packet communication. (PCDIF) 10B receives TDM data T M communication devices, 20B is a packet communication device that receives the packet data.
[0020]
Next, an example transmission frame will be described. FIG. 4 is a diagram for explaining a transmission frame according to the first embodiment, and basically shows a case where one or more types of packet data are multiplexed and transmitted in a payload portion for transmitting TDM data. ing. In the figure, a transmission frame i at a certain point in time and the next transmission frame j are shown. A transmission frame is composed of an overhead part and a payload part, and a head frame synchronization signal (Fsync), parity bit information for monitoring a transmission path error, and the like are embedded in the overhead part. As the overhead information, information used in SONET, SDH, and the like can be used, and thus description thereof is omitted here.
[0021]
In this embodiment, the unused area of the overhead part is used to write the packet data type information and the offset information of the area where the packet data is mounted on the payload. Note that where these pieces of information are written in the overhead section is fixed or previously decided between transmission and reception.
[0022]
FIG. 4 shows a case where two types of packet data are mounted. “Packet A” is the type information of the packet data sent from the packet communication device 20A, and “Packet B” is the type information of the system monitoring packet data generated by the own station. The offset information indicating the payload area includes a “start offset” indicating the start slot position of the packet data area and an “end offset” indicating the end slot position. The area designation may be expressed by “start offset” and “number of data” or “number of slots”.
The payload part can be addressed in units of bytes (slots), and various data are mapped here. The first payload slot in a row with the frame synchronization signal “Fsync” is the offset number “0”, and the last payload slot of one transmission frame is the offset number “X”. In the example shown in the figure, “start offset” of “packet A” = “M”, “end offset” = “N”, and packet data “PcA1”, “PcA2”,. There is no need to perform header or format conversion on the packet data received from the packet communication device 20A, and the packet data as received are sequentially mounted in the area. Further, “start offset” = “P” and “end offset” = “Q” of “packet B”, and packet data “PcB1”, “PcB2”,. In other areas of the payload portion, TDM data such as audio data is mapped in order corresponding to the slots of channels CH1 to CHn.
[0023]
Next, the operation of this transmission system will be described taking the case of transmitting the transmission frame of FIG. 4 as an example. In FIG. 2, input TDM data is received by a TDMIF unit 31 and input to a flow rate monitoring unit 32 after processing such as serial / parallel (S / P) conversion. In the flow rate monitoring unit 32, the write control unit 34 sequentially writes the input TDM data in the FIFO buffer 33, measures the flow rate of the write data, and outputs the measurement result to the flow rate control unit 46. On the other hand, the input packet data is received by the PCDIF unit 41 and input to the flow rate monitoring unit 42 after processing such as serial / parallel (S / P) conversion. In the flow rate monitoring unit 42, the write control unit 44 sequentially writes the input packet data in the FIFO buffer 43, measures the flow rate of the write data, and outputs the measurement result to the flow rate control unit 46. The flow rate is measured, for example, by counting the number of data written per unit time. The FIFO buffers 33 and 43 both have a sufficient capacity. However, in order to avoid overflow of the FIFO buffer 33/43, if the data storage amount exceeds a predetermined ratio, that fact is a flow rate. The control unit 46 is informed.
[0024]
The flow control unit 46 determines and outputs the read size of TDM data and packet data (ratio mounted in the payload part) based on the input flow measurement result. The read control units 35 and 45 read the corresponding flow rate data from the FIFO buffers 33 and 43 based on the read size information, and the data mapping unit 51 maps each read data to each area provided for the payload.
[0025]
Preferably, data from the FIFO buffers 33 and 43 is read in consideration of a preset priority order. An example priority is
(1) System alarm packet B
(2) TDM data that requires real-time performance such as voice
(3) User packet A, ATM cell, normal monitoring packet, monitoring cell
The lower the number, the higher the priority.
[0026]
Now, it is assumed that TDM data and user packet A are transmitted at a payload occupancy rate of, for example, 7: 3 according to the respective measured flow rates. In this state, if an alarm on the system is detected by the transmission apparatus 100A, the alarm packet B for notifying the transmission apparatus 100B of the alarm has a high priority (1). In such a case, the alarm packet B generated by the transmission device 100A can be preferentially mounted on the payload portion and transmitted regardless of the measured flow rate. By setting priorities in this way, system monitoring data is usually mixed with TDM data and sent regularly, and when an alarm occurs, an alarm packet can be sent immediately, and the data transmission service and system Management and operation can be performed efficiently.
[0027]
Each of the mapped data is multiplexed on the payload portion of the next frame by the MUX unit 52. On the other hand, in the overhead portion of the previous frame, the overhead insertion unit 53 writes the identification information of various multiplexed data and offset value information indicating these mapping (multiplexed) areas at a required position. Each transmission frame (electrical signal) formed in this way is converted into serial data, converted into an optical signal by the E / 0 unit 54, and transmitted to the optical fiber 200.
[0028]
In FIG. 3, a transmission frame (optical signal) transmitted from the opposite device 100A through the optical fiber 200 is converted into an electric signal by the O / E unit 61 of the transmission device 100B, and then S / P converted to extract overhead. Input to the unit 62. The overhead extraction unit 62 uses the frame synchronization signal (Fsync) in the overhead to perform frame synchronization, and extracts and outputs identification information and region designation information (offset value) of various multiplexed data based on the frame synchronization signal (Fsync). The DMUX unit 63 separates various multiplexed data based on corresponding area designation information.
[0029]
In the example of FIG. 4, the packet A is separated from “start offset = M” to “end offset = N” in the payload portion of the next frame, and from “start offset = P” to “end offset = Q”. Packet B is separated, and TDM data is separated from other areas.
[0030]
The data demapping unit 64 demaps the data in each area. The demapping of the packet data does not require a separate header process as a packet, and it is only necessary to accumulate the data separated from the payload portion in order. Various kinds of data (TDM data, packet data, etc.) demapped in this way are sent to the TDM communication apparatus 10B and the packet communication apparatus 20B via the corresponding IF units 65 and 66, respectively. If necessary, processing as packet data is performed by the PCDIF unit 56.
[0031]
  As described above, according to the first embodiment, the previous frame is displayed.-With the simple area designation information written in the barhead part, the payload part of the next frame can be freely separated and handled as a virtual space, and even if the form of the data multiplexed in the frame is not unified, the heterogeneous form Data (TDM data, various packet data, cell data, etc.) can be easily stored and transmitted in the same frame.
[0032]
FIG. 5 is a diagram for explaining a transmission frame according to the second embodiment. Basically, the next frame for mounting the TDM data is based on the information representing the mounting pattern of the different data mounted in the overhead portion of the previous frame. In this example, one or two or more areas are provided on the payload, and packet data and / or cell data are mounted in the area for transmission. The configuration of this communication system may be the same as that shown in FIGS. Below, a different part from 1st Embodiment is demonstrated.
[0033]
In FIG. 5, “mounting pattern” information is written in the overhead portion of the transmission frame i. In an example mounting pattern, TDM data of user channels CH1 to CH3 is multiplexed in the first three slots (that is, offset numbers “0” to “2”) in the payload of the next frame, and the subsequent three slots ( That is, offset numbers “3” to “5”) indicate that 3 bytes (slots) of user packet A are cut out and multiplexed. In the following, this mounting pattern is repeated until the end of the payload portion (however, a multiple of 6 slots). If necessary, the size of the mounting pattern (slot size per pattern) and the division ratio can be changed according to each measured flow rate. On the other hand, on the receiving side of the transmission frame, each corresponding data is demapped from the payload portion of the next frame based on the “mounting pattern” information extracted from the overhead portion of the previous frame. Therefore, according to the second embodiment, data of different types can be efficiently contained in the same frame and transmitted by simpler area designation information that simply specifies the mounting pattern of the data of different types. Things are possible.
[0034]
In each of the above embodiments, basically, a case has been described in which one or more types of packet data are multiplexed and transmitted in a payload portion for transmitting TDM data. However, the present invention is not limited to this. The payload area may be divided by adding data identification information and area designation information or mounting pattern information to the TDM data.
[0035]
In each of the above embodiments, TDM data and packet data (Ethernet packet, IP packet, etc.) are multiplexed and transmitted. However, the present invention is not limited to this. It goes without saying that ATM cells (fixed length packet data) may be multiplexed and transmitted.
[0036]
Moreover, although several embodiment suitable for the said invention was described, it cannot be overemphasized that the structure of each part, control, a process, and these combination can be variously changed within the range which does not deviate from this invention. .
[0037]
(Supplementary note 1) A data transmission method of a system for transmitting a plurality of transmission frames having an overhead part and a payload part in time series, wherein the payload part of the next frame is data identification information mounted on the overhead part of the previous frame; A data transmission method characterized in that data is divided into a plurality of areas according to information representing an area on the next frame payload portion, and different types of data are mounted and transmitted in each area.
[0038]
(Supplementary note 2) A data transmission method of a system for transmitting a plurality of transmission frames having an overhead part and a payload part for mounting time division multiplexed data in time series, wherein One or more areas are provided by data identification information mounted in the overhead part of the frame and information indicating an area on the next frame payload part, and packet data and / or cell data are mounted in the area for transmission. Data transmission method.
[0039]
(Supplementary note 3) A data transmission method for a system for transmitting a plurality of transmission frames having an overhead part and a payload part in time series, and mounting different types of data in which the payload part of the next frame is mounted on the overhead part of the previous frame A data transmission method characterized in that data is divided into a plurality of areas according to information representing a pattern, and different types of data are mounted and transmitted in each area.
[0040]
(Supplementary note 4) A data transmission method of a system for transmitting a plurality of transmission frames having an overhead part and a payload part for mounting time division multiplexed data in time series, wherein A data transmission method characterized in that one or two or more areas are provided according to information representing a mounting pattern of different kinds of data mounted in an overhead part of a frame, and packet data and / or cell data are mounted in the area and transmitted.
[0041]
(Additional remark 5) The data transmission method of Additional remark 1 or 2 characterized by the information showing the area | region on a payload part consisting of the start offset value and end offset value of the area | region in a next frame payload part.
[0042]
(Additional remark 6) The data transmission method of Additional remark 1 or 2 characterized by the information showing the area | region on a payload part consisting of the start offset value and data amount of the area | region in a next frame payload part.
[0043]
(Supplementary note 7) A data transmission apparatus of a system for transmitting a plurality of transmission frames having an overhead part and a payload part for mounting time division multiplexed data in time series, the time division multiplexed data and packet data and / or cell A receiving section that terminates data reception, a buffer section that buffers each received data, and a payload section of the next frame transmitted by the local station. A data transmission apparatus comprising: a data mapping unit that provides one or two or more areas of a predetermined size according to information representing an area on the frame payload portion and mounts packet data and / or cell data in the area .
[0044]
(Supplementary note 8) The data transmission device according to supplementary note 7, further comprising a flow rate measurement unit that measures a flow rate of each received data, wherein the data mapping unit changes a size of data mounted on the payload unit according to the measured flow rate. .
[0045]
【The invention's effect】
As described above, according to the present invention, since different types of data can be mapped to the same transmission frame in the same data format, processing for unifying data becomes unnecessary, and complicated data conversion processing and extra processing circuits are required. I don't need it. In addition, since there is no need to newly packetize, the header area added in the past in the packetization becomes unnecessary, and the transmission efficiency is improved.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating the principle of the present invention.
FIG. 2 is a diagram (1) illustrating a configuration of a data transmission system according to an embodiment;
FIG. 3 is a diagram (2) illustrating the configuration of the data transmission system according to the embodiment;
FIG. 4 is a diagram illustrating a transmission frame according to the first embodiment.
FIG. 5 is a diagram illustrating a transmission frame according to the second embodiment.
[Explanation of symbols]
10 TDM communication equipment
20 Packet communication device
31, 65 TDM interface (TDMIF)
32, 42 Flow rate monitoring unit
33, 43 FIFO buffer (FIFO)
34, 44 Write controller (WC)
35, 45 Read controller (RC)
41, 66 Packet interface unit (PCDIF)
46 Flow control unit
51 Data mapping part
52 Multiplexer (MUX)
53 Overhead insertion part
62 Overhead extraction unit
63 Separation unit (DMUX)
64 Data demapping part
100 Transmission equipment
200 Optical transmission line (optical fiber)

Claims (5)

A data transmission method for a system for transmitting a plurality of transmission frames having an overhead part and a payload part in time series,
Data identification information for identifying different types of data to be mapped to the payload portion of the next transmission frame in the overhead portion of a transmission frame, and data corresponding to this identification information are mapped to the payload portion of the next transmission frame And the position information at the time of transmission
A data transmission method characterized in that data in a form indicated by the data identification information is mounted and transmitted at a position indicated by the position information as a transmission frame subsequent to the certain transmission frame . The heterogeneous data is packet data and / or cell data ,
2. The data transmission method according to claim 1 , wherein a plurality of the data identification information and the corresponding position information are mounted in an overhead part of the certain transmission frame . A data transmission method for a system for transmitting a plurality of transmission frames having an overhead part and a payload part in time series,
In the overhead part of a certain transmission frame, information representing a mounting pattern of a plurality of heterogeneous data to be mapped to the payload part of the next transmission frame is mounted and transmitted,
A data transmission method characterized in that, as a transmission frame next to the certain transmission frame, the plurality of different types of data are mounted and transmitted at positions defined by the mounting pattern . A data transmission device of a system for transmitting a plurality of transmission frames having an overhead part and a payload part in time series,
A receiving unit for receiving and terminating time division multiplexed data and packet data and / or cell data from an external device ;
And Baffaringusu Ru buffer unit in each of the reception data received by the reception unit,
Data identification information of packet data and / or cell data mapped to the payload portion of the next transmission frame, and data corresponding to this identification information are transmitted to the overhead portion of a certain transmission frame transmitted by the local station, and An overhead insertion part for inserting position information when mapping to the payload part;
Packet data and / or cells stored in the buffer unit according to the data identification information inserted by the overhead insertion unit and position information corresponding to the payload portion of the next transmission frame to be transmitted by the local station A data transmission apparatus comprising: a data mapping unit that maps data. It has a flow rate measurement unit that measures the flow rate of each received data,
5. The data transmission apparatus according to claim 4, wherein the data mapping unit changes a size of packet data and / or cell data to be mapped to the payload according to the measured flow rate.

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