JP3480548B2 - Cell disassembly transmission method and apparatus - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cell disassembling and transmitting method and device, which can be applied to, for example, an AAL type 1 network.

[0002]

2. Description of the Related Art Telecommunication Standardization Sector (International Telecom) in the International Telecommunication Union
unity Union-Telecommu
nication Standardization
Sector; hereinafter referred to as “ITU-T”) Section 2.5.2.3 (Structured Data Transfer (SDT) Method) of 363 (B-ISDN ATM Adaptation Layer (AAL) Specification) describes AAL Type 1
The method of using a pointer to indicate the boundary of the structure is defined in.

According to the above-mentioned recommendation, a pointer field is provided for every other ATM cell to be transferred, and structured data is provided in the data part of the ATM cell provided with the pointer field and the data part of the next ATM cell. If there is a boundary (structured head), the receiver side can recognize the boundary, so the pointer value (value indicating the number of octets from the beginning of the data part that boundary) is present in the pointer field. It is to set.

[0004]

However, the above-mentioned recommendation only indicates that the pointer field is provided in the ATM cell, and the ATM cell is actually decomposed at the cell receiving side to form the user data which is the structured data. There is a problem that the cell disassembling and transmitting method and device for transmitting the cell to the user side are not shown and have not been realized.

Therefore, what is applicable when user data is multiplexed by a plurality of logical channels and there is an arbitrary structured head for each logical channel, and what is applicable when there is no structured head is realized. Was not there.

Therefore, there has been a demand for a cell disassembling and transmitting method and apparatus capable of disassembling an ATM cell provided with a pointer and transmitting user data which is structured data.

[0007]

In order to solve such a problem, the first aspect of the present invention decomposes a cell transmitted from an ATM network at a fixed speed to generate user data which is structured data, and In the cell disassembly transmission method for transmitting user data to the user side network, (1)
A cell reception disassembly process for receiving a cell transmitted from the ATM network and disassembling the cell into user data and a pointer; and (2) queuing the user data disassembled by the cell reception disassembly process, A user data read control process for extracting user data queued based on a fixed speed, and (3) determining a structured start position of the user data from the pointer decomposed by the cell reception decomposition process and the fixed speed, and Cell-side structured head instruction processing for outputting the cell-side structured head signal at the same time that the user data at the determined structured head position portion is extracted by the user data read control processing,
(4) If the structured head signal from the user side generated based on the fixed speed does not match the cell-side structured head signal output by the cell-side structured head instruction processing, the user The user data extracted by the user data read control processing is discarded until the structured head signals on the user side and the cell side match next time, and when the structured head signals on the user side and the cell side match. ,
And structured match determination control processing for sending the extracted user data to the user side network.

A second aspect of the present invention is a cell disassembling and transmitting apparatus for disassembling a cell transmitted from an ATM network at a fixed speed to generate user data which is structured data and transmitting the user data to the user side network. In (1) cell reception disassembling means for receiving a cell transmitted from the ATM network and disassembling the cell into user data and a pointer; and (2) user data disassembled by the cell reception disassembling means. User data read control means for queuing and extracting user data queued based on the fixed speed; (3) Structured start position of user data based on the pointer decomposed by the cell reception decomposition means and the fixed speed. And the user data at the determined structured start position is the above user data read system. Cell side structured head indicating means for outputting the cell side structured head signal at the same time when it is taken out by the means, and (4) the structured head signal from the user side generated based on the fixed speed and the cell side structured signal. If the cell-side structured head signal output by the head instruction means does not match, the user-data read control means takes out until the user-side and cell-side structured head signals match next time. User data is discarded, and when the structured head signals on the user side and the cell side match, the structured user equipment has structured match determination control means for sending the extracted user data to the user side network. And

As described above, according to the first or second aspect of the present invention, the received cell is decomposed into user data and a pointer, the structured head is recognized based on the pointer, and the structure from the user side is recognized. After confirming the match with the
Since the user data is transmitted, the cell provided with the pointer can be disassembled and the user data that is structured data can be transmitted to the user side.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION (A) First Embodiment Hereinafter, a first embodiment in which the cell disassembling and transmitting method and device of the present invention are applied to an AAL type 1 network will be described with reference to the drawings. .

As shown in FIG. 1, in the first embodiment, an ATM cell receiving unit 1, a cell disassembling unit 2, a user data control unit 3, a cell side structured head designating unit 4, and a user side. It has a structured head designating unit 5, a structured matching determination unit 6, and a user data transmission unit 7. Further, the ATM cell receiving unit 1 outputs to the cell disassembling unit 2, the cell disassembling unit 2 outputs to the user data control unit 3 and the cell side structured head designating unit 4, and the user data control unit 3 outputs to the cell disassembling unit 2. And the cell side structured head instructing section 4 and the structured coincidence determining section 6, and the cell side structured head instructing section 4 outputs to the structured coincidence determining section 6.
The user-side structured head determination unit 5 outputs the structured match determination unit 6 and the structured match determination unit 6 outputs the user data transmission unit 7.

The ATM cell receiving section 1 receives an ATM cell transmitted from the ATM network and
The M cell is output to the cell disassembly unit 2.

The cell disassembling unit 2 uses the input ATM cell as a user data portion and a pointer portion (pointer field).
And the user data set in the user data portion is sequentially queued in a queuing unit (not shown). As will be described later, when a read signal is input from the user data control unit 3, the queuing unit sequentially outputs user data one octet at a time to the user data control unit 3 and the user of the one octet. If the data is the first part of the user data part disassembled from the ATM cell and the pointer value is set in the pointer part of the ATM cell, the pointer value is output to the cell side structured head designating section 4.

Here, the pointer value indicates, when the data portion of the ATM cell has a boundary of user data, the position of the boundary from the beginning of the data portion.
It is set in the pointer portion of the ATM cell. Therefore, if there is no boundary of user data in the data portion of the ATM cell, nothing is set in the pointer portion.

The user data control section 3 is supplied with the read timing signal output from the user side, and based on the read timing signal, the read signal is applied to the cell disassembling section 2.
To the cell-side structured head designating unit 4. as a result,
When one octet of user data is input from the cell disassembling unit 2, the user data is output to the structured match determining unit 6.

When the pointer value is input from the cell disassembling unit 2, the cell-side structured head designating unit 4 stores the pointer value in a pointer storage unit (not shown), and the read signal is input from the user data control unit 3. The pointer value is decremented each time. As a result, when the pointer value becomes 0 (that is, the boundary of the user data is detected), the cell structured head signal is output to the structured coincidence determination unit 6.

The user-side structured head instruction unit 5 receives the structured head signal output from the user side, and based on the structured head signal, sends the user structured head signal to the structured coincidence determination unit 6. Output to.

In the first embodiment, the user side outputs two reference signals (reading timing signal and structured head signal). First, the reading timing signal is the network on the user side. Is the timing generated by the user side to read the user data from the cell disassembly unit 2 so as to match the fixed transmission rate of the structured data, and the structured head signal is the structured data generated by the user side based on the read timing. Is a signal indicating the first byte of.

Therefore, if the user data is normally read based on the read timing generated by the user side, the cell structured head signal output by the cell side structured head instruction unit 4 is also the user side. The timing should match with the user structured head signal output based on the structured head signal generated by itself.

When the cell structured head signal input from the cell side structured head instructing section 4 and the user structured head signal input from the user side structured head instructing section 5 do not match, the structured coincidence judging section 6 determines that The user data input from the user data control unit 3 is output to the user data transmission unit 7 as it is except for the case where only one of the signals is output. During this period, the user data input from the user data control unit 3 is discarded and is not output to the user data transmission unit 7.

When the user data is input from the structured match determination unit 6, the user data transmission unit 7 transmits the user data to the user side network.

Next, the operation of the first embodiment will be described with reference to FIG.

A sent from the ATM network
The TM cell is received by the ATM cell receiving unit 1 and output to the cell disassembling unit 2. In the cell disassembling unit 2, the ATM cell is disassembled into a user data portion and a pointer portion and set in the user data portion. The user data is sequentially queued in a queuing unit (not shown).

When a read signal is input from the user data control section 3, the queuing section outputs user data one by one octet to the user data control section 3 each time the user data control section 3 receives the read signal. If the data is the first part of the user data part decomposed from the ATM cell and the pointer value is set in the pointer part of the ATM cell, the pointer value is output to the cell side structured head designating part 4. .

In the user data control unit 3, the read timing signal output from the user side is input, and based on the read timing signal, the read signal is transmitted to the cell disassembling unit 2 and the cell side structured head designating unit 4. Is output to. As a result, when one octet of user data is input from the cell disassembling unit 2, the user data is output to the structured match determining unit 6.

In the cell side structured head designating section 4, when the pointer value is inputted from the cell disassembling section 2, it is stored in a pointer storing section (not shown), and a read signal is inputted from the user data control section 3. Each time, the pointer value is decremented. As a result, when the pointer value becomes 0 (that is, the boundary of the user data is detected), the cell structured head signal is output to the structured coincidence determination unit 6.

The user-side structured head instruction unit 5 receives the structured head signal output from the user side, and based on the structured head signal, the user structured head signal is the structured coincidence determination unit 6. Is output to.

In the structured coincidence determination section 6, when the cell structured head signal input from the cell side structured head instruction section 4 and the user structured head signal input from the user side structured head instruction section 5 do not match. Except (when only one of the signals is output), the user data input from the user data control unit 3 is directly output to the user data transmission unit 7 and transmitted to the user side network. Next, until the two signals match, the user data input from the user data control unit 3 is discarded,
It is not sent to the user side network.

As described above, according to the first embodiment, the user data and the pointer value are decomposed from the received ATM cell, and the structured head on the cell side is recognized based on the pointer value. By confirming the match with the structured head signal from the user side and then transmitting the user data to the user side, it is possible to disassemble the ATM cell provided with the pointer and transmit the structured data.

(B) Second Embodiment A second embodiment in which the cell disassembling and transmitting method and apparatus of the present invention are applied to an AAL type 1 network will be described below with reference to the drawings.

As shown in FIG. 2, in this second embodiment, an ATM cell receiving unit 1, a cell disassembling unit 2, a user data control unit 3, a cell side structured head designating unit 4, and a user side. Structured head designating unit 5, structured match determination unit 6, user data transmission unit 7, cell-side structured number holding unit 8, and TS
It has a logical channel conversion table section 9. Here, in FIG. 2, parts that are the same as or correspond to those in FIG. 1 showing the configuration of the above-described first embodiment are denoted by the same reference numerals, and therefore the differences from the first embodiment will be mainly described below. explain. Further, the cell-side structured number holding unit 8 inputs / outputs with the cell-side structured head instruction unit 4, and the TS logical value channel conversion table unit 9 inputs / outputs with the user-side structured head instruction unit 5.

Here, in the second embodiment,
ATM cells to be input and user data to be output are time slots (hereinafter referred to as “TS”) for each logical channel.
Are provided and time-division multiplexed. Here, for example, a TS for each logical channel as shown in the upper right of FIG. 4 is provided. As will be described later, this second
In the embodiment, the signal for indicating which logical channel TS is currently being output by the user-side structured head designating unit 5.

The cell disassembling unit 2 receives the logical channel input from the user side structured head designating unit 5 and the ATM cell receiving unit 1.
If the logical channel of the ATM cell input from the same is the same, that ATM cell performs the same processing as in the first embodiment. If they are not the same, the input ATM cell is discarded and the ATM cell is not output.

When the logical channel is switched, the ATM cell of the previous logical channel is not stored in the queuing unit of the cell disassembling unit 2, and the processing of the previous logical channel is completed in all blocks. It is assumed that FIG. 3 is a detailed block diagram of the cell-side structured head designating unit 4 and the cell-side structured number holding unit 8. As shown in FIG. 3, the cell-side structured number holding unit 8 stores a pointer value for each logical channel.

When the pointer value is input from the cell disassembling unit 2, the cell-side structured head designating unit 4 stores the pointer value in the pointer storage unit 4a as the pointer value of the logical channel being input at that time and the user data. When the read signal is input from the control unit 3, the pointer value is decremented,
When the pointer value becomes 0, the cell structured head signal is output to the structured coincidence determination unit 6. Here, when the logical channel input from the user-side structured head designating unit 5 is switched, the pointer value stored in the pointer storage unit 4a is stored in the logical channel before replacement in the cell-side structured number holding unit 8, and The pointer value of the replaced logical channel is read and stored in the pointer storage unit, and the same processing is performed.

FIG. 4 shows the user-side structured head designating unit 5 and T.
FIG. 6 is a block diagram for explaining an S logical channel conversion table unit 9. As shown in FIG. 4, the TS logical channel conversion table unit 9 stores the structured head signal information and the logical channel for each TS. The structured head signal information stores information on whether or not to output the structured head signal in the TS, and in this case, top is stored if it is output, and non is stored if it is not output.

The user-side structured head designating section 5 sets the TS number to T at the predetermined upper right timing in FIG.
S logical channel conversion table section 9 outputs the result,
When the structured head signal of the TS number and the logical channel are input from the TS logical channel conversion table unit 9, the logical channel is transferred to the cell disassembly unit 2, the user data control unit 3, and the cell side structured head designating unit 4. When the structured head signal is input (when top), the user structured head signal is output to the structured coincidence determination unit 6.

Next, the operation of the second embodiment will be described with reference to FIGS.

A sent from the ATM network
The TM cell is received by the ATM cell receiving unit 1 and output to the cell disassembling unit 2. In the cell disassembling unit 2, the ATM cell is disassembled into a user data portion and a pointer portion and set in the user data portion. The user data is sequentially queued in a queuing unit (not shown). However, at this time, if the logical channel input from the user-side structured head instruction unit 5 and the logical channel of the ATM cell input from the ATM cell receiving unit 1 are not the same, the input ATM cell is not queued. Be discarded.

When a read signal is input from the user data control unit 3, the queuing unit sequentially outputs user data one octet to the user data control unit 3 each time the read signal is input to the user data control unit 3. If the data is the first part of the user data part decomposed from the ATM cell and the pointer value is set in the pointer part of the ATM cell, the pointer value is output to the cell side structured head designating part 4. .

In the user data control unit 3, the read timing signal output from the user side is input, and based on the read timing signal, the read signal is transmitted to the cell disassembling unit 2 and the cell side structured head designating unit 4. Is output to. As a result, when one octet of user data is input from the cell disassembling unit 2, the user data is output to the structured match determining unit 6.

When the pointer value is input from the cell disassembling unit 2, the cell-side structured head designating unit 4 uses the pointer storage unit 4a as the pointer value of the logical channel being input at that time.
When the read signal is input from the user data control unit 3, the pointer value is decremented,
Further, when the pointer value becomes 0, the cell structured head signal is output to the structured coincidence determination unit 6. Here, when the logical channel input from the user-side structured head instruction unit 5 is switched, the pointer value stored in the pointer storage unit 4a is stored in the logical channel before the replacement in the cell-side structured number holding unit 8 and The pointer value of the replaced logical channel is read and stored in the pointer storage unit, and the same processing is performed.

The user-side structured head designating section 5 outputs the TS number to the TS logical channel conversion table section 9 at a predetermined timing in the upper right of FIG.
When the structured head signal of the TS number and the logical channel are input from the S logical channel conversion table unit 9, the logical channel goes to the cell disassembling unit 2, the user data control unit 3, and the cell side structured head instructing unit 4. When the structured head signal is output (when top), the user structured head signal is output to the structured coincidence determination unit 6.

In the structured match determination unit 6, when the cell structured head signal input from the cell side structured head designating unit 4 does not match the user structured head signal input from the user side structured head designating unit 5. Except (when only one of the signals is output), the user data input from the user data control unit 3 is directly output to the user data transmission unit 7 and transmitted to the user side network. Next, until the two signals match, the user data input from the user data control unit 3 is discarded,
It is not sent to the user side network.

As described above, according to the second embodiment, the user data and the pointer value are decomposed from the received ATM cell, and the structured head on the cell side is recognized based on the pointer value. By confirming the match with the structured head signal from the user side and then transmitting the user data to the user side, it is possible to disassemble the ATM cell provided with the pointer and transmit the structured data.

Further, according to the second embodiment, it is also applicable to the case where the user data is multiplexed by a plurality of logical channels and each logical channel has an arbitrary structured head.

(C) Third Embodiment A third embodiment in which the cell disassembling and transmitting method and apparatus of the present invention are applied to an AAL type 1 network will be described below with reference to the drawings.

As shown in FIG. 5, in the third embodiment, an ATM cell receiving unit 1, a cell disassembling unit 2, a user data control unit 3, a cell side structured head designating unit 4, and a user side. Structured head designating unit 5, structured match determination unit 6, user data transmission unit 7, cell-side structured number holding unit 8, and TS
It has a logical channel conversion table unit 9, a dummy data storage unit 10, and a selection unit 11. Here, in FIG. 5, parts that are the same as or correspond to those in FIG. 2 showing the configuration of the above-described second embodiment are denoted by the same reference symbols, and therefore, in the following, differences from the second embodiment will be mainly described. explain.
Further, the dummy data storage unit 10 outputs to the selection unit 11,
The selection unit 11 inputs from the user data control unit 3, the structured match determination unit 6 and the dummy data storage unit, and outputs it to the user data transmission unit 8.

The dummy data storage unit 10 stores dummy data to be output instead when the user data is not output from the user data control unit 3.

FIG. 6 is a table showing the processing conditions of the structured match determination unit 6. As shown in FIG. 6, the structured coincidence determination unit 6 of the third embodiment performs processing by further finer condition division than in the second embodiment. First, when there is no cell-side structured head signal and there is a user-side structured head signal (in the case of No1), it notifies the selection unit 11 that user data can be output because it corresponds to an ATM cell without a pointer portion, When the cell-side structured head signal is present and the user-side structured head signal is not present (No2), dummy data output is notified to the selection unit 11 until the user-side structured head signal is present, and then the user-side structured head signal is output. When the head signal is output, it notifies that user data can be output. Of course, when there is a cell-side structured head signal and also a user-side structured head signal (No3) and when there is no cell-side structured head signal and no user-side structured head signal (No4) ,
Similar to the second embodiment, the selection unit 11 is notified that user data can be output.

When the structured coincidence determination unit 6 notifies the selection unit 11 that user data can be output, the selection unit 11 transmits the user data input from the user data control unit 3 to the user data transmission unit 7.
To the dummy data output notification,
The dummy data is read from the dummy data storage unit 10 and output to the user data transmission unit 8.

Next, the operation of the third embodiment will be described with reference to FIG. 5 or FIG.

A sent from the ATM network
The TM cell is received by the ATM cell receiving unit 1 and output to the cell disassembling unit 2. In the cell disassembling unit 2, the ATM cell is disassembled into a user data portion and a pointer portion and set in the user data portion. The user data is sequentially queued in a queuing unit (not shown). However, at this time, if the logical channel input from the user-side structured head instruction unit 5 and the logical channel of the ATM cell input from the ATM cell receiving unit 1 are not the same, the input ATM cell is not queued. Be discarded.

When a read signal is input from the user data control unit 3, the queuing unit outputs user data one octet at a time to the user data control unit 3 and the user of the one octet. If the data is the first part of the user data part decomposed from the ATM cell and the pointer value is set in the pointer part of the ATM cell, the pointer value is output to the cell side structured head designating part 4. .

In the user data control unit 3, the read timing signal output from the user side is input, and based on the read timing signal, the read signal is transmitted to the cell disassembling unit 2 and the cell side structured head designating unit 4. Is output to. As a result, when one octet of user data is input from the cell disassembling unit 2, the user data is output to the selecting unit 11.

When the pointer value is input from the cell disassembling unit 2, the cell-side structured head designating unit 4 sets the pointer storage unit 4a as the pointer value of the logical channel being input at that time.
When the read signal is input from the user data control unit 3, the pointer value is decremented,
Further, when the pointer value becomes 0, the cell structured head signal is output to the structured coincidence determination unit 6. Here, when the logical channel input from the user-side structured head instruction unit 5 is switched, the pointer value stored in the pointer storage unit 4a is stored in the logical channel before the replacement in the cell-side structured number holding unit 8 and The pointer value of the replaced logical channel is read and stored in the pointer storage unit, and the same processing is performed.

The user-side structured head designating section 5 outputs the TS number to the TS logical channel conversion table section 9 at a predetermined upper right timing shown in FIG.
When the structured head signal of the TS number and the logical channel are input from the S logical channel conversion table unit 9, the logical channel goes to the cell disassembling unit 2, the user data control unit 3, and the cell side structured head instructing unit 4. When the structured head signal is output (when top), the user structured head signal is output to the structured coincidence determination unit 6.

Structured coincidence determination unit 6 of the third embodiment
Then, as shown in FIG. 6, when there is no cell-side structured head signal but there is a user-side structured head signal (No1)
Since it corresponds to an ATM cell without a pointer portion, the selection unit 11 is notified that user data can be output, and if there is a cell-side structured head signal and no user-side structured head signal (No2), The selection unit 11 is notified of the output of the dummy data until the user-side structured head signal is present, and when the user-side structured head signal is output thereafter, the user data output is notified. Of course, when there is a cell-side structured head signal and also a user-side structured head signal (No3) and when there is no cell-side structured head signal and no user-side structured head signal (No4) As in the second embodiment, the selection unit 11 is notified that user data can be output.

In the selection unit 11, when the structured-match determination unit 6 notifies that the user data can be output, the user data input from the user data control unit 3 is output to the user data transmission unit 7 as it is, and the user side network is output. When the dummy data output is notified, the dummy data is read from the dummy data storage unit 10 and similarly transmitted to the user side network.

As described above, according to the third embodiment, the user data and the pointer value are decomposed from the received ATM cell, and the structured head on the cell side is recognized based on the pointer value. By confirming the match with the structured head signal from the user side and then transmitting the user data to the user side, it is possible to disassemble the ATM cell provided with the pointer and transmit the structured data.

The third embodiment can also be applied to the case where user data is multiplexed by a plurality of logical channels and an arbitrary structured head is provided for each logical channel.

Furthermore, according to the third embodiment, even when the structured head signals of both do not match, the user data is not discarded, and it can be applied to an ATM cell having no pointer field.

(D) Fourth Embodiment A fourth embodiment in which the cell disassembly and transmission method and apparatus of the present invention are applied to an AAL type 1 network will be described below with reference to the drawings.

As shown in FIG. 7, in the fourth embodiment, the ATM cell receiving unit 1, the cell disassembling unit 2, the user data control unit 3, the user data transmitting unit 7, and the cell side structured number. Holding 8, TS logical channel conversion table unit 9,
It has a cell side structured head operation unit 12, a user side structured head operation unit 13, a structured operation comparison unit 14, and a user data reading unit 15. Here, in FIG. 7, parts that are the same as or correspond to those in FIG. 2 showing the configuration of the above-described second embodiment are denoted by the same reference numerals, and therefore, in the following, differences from the second embodiment will be mainly described. explain. Further, the cell-side structured head calculation unit 12 receives inputs from the cell decomposition unit 2, the user data control unit 3, and the user-side structured head calculation unit 13,
Input / output to / from the cell side structured number holding unit 8 and output to the structured operation / comparison unit 14; user side structured head operation unit 13 inputs / outputs to / from the TS logical channel conversion table unit 9;
To the cell-side structured head operation unit 12, the structured operation comparison unit 14 outputs to the user data read control unit 7, and the user data read unit 15 to the user data control unit 3 and the structured operation comparison unit 14. From the user data output unit 7.

The cell-side structured head operation unit 12 is
This is mainly similar to the cell-side structured head designating unit 4 in the above embodiment, but when the pointer value is input from the cell disassembling unit 2, the expected time at which the pointer value becomes 0 can be calculated. . When the scheduled time is calculated here, it is output to the structured operation comparison unit 14 as the next cell structured head signal.

The user-side structured head operation unit 13 is mainly the same as the user-side structured head instruction unit 5 in the second embodiment, but the next structured head signal that has not been actually input has been input. It is possible to calculate the expected input time of. When the scheduled input time of the next structured head signal is calculated, the scheduled time is output to the structured operation / comparison unit 14 as the next user structured head signal.

The structured operation comparison unit 14 receives the expected time of the next cell structured head signal input from the cell side structured head operation unit 12 and the next user structured head signal input from the user side structured head operation unit 13. If the scheduled times of the two coincide with each other, the user data output unit 15 is notified that the user data can be output and the scheduled times of the coincidence are output. If the times do not match, the user waits until the next scheduled time matches. The data read unit 15 is notified that the user data cannot be output and outputs the scheduled time that does not match.

When the structured data comparison unit 14 notifies the user data output and the output of the scheduled time, the user data reading unit 15 inputs the user data from the user data control unit 3 at the scheduled time. Preparation for outputting the user data to the user data transmitting unit 7 as it is is performed in advance, and at the scheduled time, the user data is output to the user data transmitting unit 7 as prepared. Further, if there is a notification that the user data cannot be output and the scheduled time is output, preparation is made in advance for discarding the user data input from the user data control unit 3 when the scheduled time comes,
When the scheduled time comes, the user data is discarded as prepared and the user data is not output.

Next, the operation of the fourth embodiment will be described with reference to FIG.

A sent from the ATM network
The TM cell is received by the ATM cell receiving unit 1 and output to the cell disassembling unit 2. In the cell disassembling unit 2, the ATM cell is disassembled into a user data portion and a pointer portion and set in the user data portion. The user data is sequentially queued in a queuing unit (not shown). However, at this time, if the logical channel input from the user-side structured head instruction unit 5 and the logical channel of the ATM cell input from the ATM cell receiving unit 1 are not the same, the input ATM cell is not queued. Be discarded.

When a read signal is input from the user data control unit 3, the queuing unit outputs user data one octet at a time to the user data control unit 3 and the user of the one octet. If the data is the first part of the user data part disassembled from the ATM cell and the pointer value is set in the pointer part of the ATM cell, the pointer value is output to the cell side structured head computing unit 12. .

In the user data control unit 3, the read timing signal output from the user side is input, and the read signal is transmitted to the cell disassembling unit 2 and the cell side structured head computing unit 12 based on the read timing signal. Is output to. As a result, when one octet of user data is input from the cell disassembling unit 2, the user data is output to the user data reading unit 15.

The cell-side structured head computing unit 12 is mainly similar to the cell-side structured head instructing unit 4 in the second embodiment, except that when the pointer value is input from the cell disassembling unit 2, The scheduled time when the pointer value becomes 0 is calculated, and when the scheduled time is calculated here, it is output to the structured operation comparison unit 14 as the next cell structured head signal.

The user-side structured head operation unit 13 is mainly the same as the user-side structured head instruction unit 5 in the second embodiment, but the next structured head signal that has not yet been input is actually used. When the scheduled input time of is calculated and the scheduled input time of the next structured head signal is calculated, the scheduled time is output to the structured operation comparison unit 14 as the next user structured head signal.

In the structured operation comparison unit 14, the scheduled time of the next cell structured head signal input from the cell side structured head operation unit 12 and the next user structured head signal input from the user side structured head operation unit 13 If the scheduled time of
The user data output unit 15 is notified that the user data can be output and the corresponding scheduled time is output. If the times do not match, the user data cannot be output to the user data read unit 15 until the next scheduled time matches. Will be notified.

In the user data reading unit 15, when the structured operation comparing unit 14 notifies the user data output is possible and outputs the scheduled time, the user data control unit 3 inputs the scheduled time. The preparation for directly outputting the user data to the user data transmitting unit 7 is performed in advance, and when the scheduled time comes, the user data is output to the user data transmitting unit 7 according to the preparation and transmitted to the user side network. Further, when the notification that the user data cannot be output is given, when the scheduled time comes, preparations for discarding the user data input from the user data control unit 3 are made in advance. User data is discarded and not sent to the user side network.

As described above, according to the fourth embodiment, the user data and the pointer value are decomposed from the received ATM cell, and the structured head on the cell side is recognized based on the pointer value. By confirming the match with the structured head signal from the user side and then transmitting the user data to the user side, it is possible to disassemble the ATM cell provided with the pointer and transmit the structured data.

The fourth embodiment can also be applied to the case where user data is multiplexed by a plurality of logical channels and each logical channel has an arbitrary structured head.

Furthermore, according to the fourth embodiment, it is possible to know in advance whether or not both structured head signals match, so that the processing can be prepared in advance.

(E) Fifth Embodiment Hereinafter, a fifth embodiment in which the cell disassembling and transmitting method and device of the present invention are applied to an AAL type 1 network will be described with reference to the drawings.

As shown in FIG. 8, in the fifth embodiment, an ATM cell receiving unit 1, a cell disassembling unit 2, a user data control unit 3, a user data transmitting unit 7, and a cell side structured number. Holding unit 8 and TS logical channel conversion table unit 9
It has a dummy data storage unit 10, a cell side structured head operation unit 12, a user side structured head operation unit 13, a structured operation comparison unit 14, and a user data reading unit 15. Here, in FIG. 8, parts that are the same as or correspond to those in FIG. 7, which shows the configuration of the above-described fourth embodiment, are denoted by the same reference symbols, and therefore, in the following, differences from the fourth embodiment will be mainly described. explain. In addition, the dummy data storage unit 10 outputs the data to the user data reading unit 15.

The dummy data storage unit 10 stores the dummy data to be output when the user data is not output from the user data control unit 3.

Structured operation comparison unit 1 of the fifth embodiment
4 is mainly the same as the fourth embodiment, but further has the same function as the structured match determination unit 6 in the third embodiment. That is, referring to FIG. 6,
Is the scheduled time of the structured head signal on the next cell side not input?
Alternatively, when the scheduled time of the next user-side structured head signal is faster than the scheduled time of the next-cell-side structured head signal (corresponding to No 1), the user data reading unit also supports an ATM cell having no pointer portion. A notification that the user data can be output is output to 15 and the scheduled time of the next user side structured head signal is output. Of course, the scheduled time of the next cell side structured head signal and the scheduled time of the next user side structured head signal are In the case where they match (in the case of No3), and when neither the scheduled time of the next cell-side structured head signal nor the scheduled time of the next user-side structured head signal is input (in the case of No4), the fourth embodiment Is the same as.

When the scheduled time of the next user side structured head signal is later than the scheduled time of the next cell side structured head signal (corresponding to No 2), the structured operation comparison of the fifth embodiment is performed. Further, a threshold value is set in advance in the unit 14, and if the time difference between the scheduled times is larger than the threshold value, it is notified that user data cannot be output.
If it is small, first, the dummy data output is notified and the scheduled time of the next cell side structured head signal is output, and then the user data output is possible notification and the scheduled time of the next user side structured head signal is output. And

When the structured data comparison unit 14 notifies the user data output permission and the output of the scheduled time, the user data reading unit 15 inputs from the user data control unit 3 at the scheduled time. Preparation for outputting the user data to the user data transmitting unit 7 as it is is performed in advance, and at the scheduled time, the user data is output to the user data transmitting unit 7 as prepared. Further, if there is a notification that the user data cannot be output and the scheduled time is output, preparation is made in advance for discarding the user data input from the user data control unit 3 when the scheduled time comes,
When the scheduled time comes, the user data is discarded as prepared and the user data is not output. Further, when the notification of the dummy data output and the output of the scheduled time are given, the dummy data is read from the dummy data storage unit 10 in advance, and when the scheduled time comes, the dummy data is output to the user data transmission unit 8.

Next, the operation of the fifth embodiment will be described with reference to FIG.

A sent from the ATM network
The TM cell is received by the ATM cell receiving unit 1 and output to the cell disassembling unit 2. In the cell disassembling unit 2, the ATM cell is disassembled into a user data portion and a pointer portion and set in the user data portion. The user data is sequentially queued in a queuing unit (not shown). However, at this time, if the logical channel input from the user-side structured head instruction unit 5 and the logical channel of the ATM cell input from the ATM cell receiving unit 1 are not the same, the input ATM cell is not queued. Be discarded.

When a read signal is input from the user data control unit 3, the queuing unit outputs user data one octet to the user data control unit 3 each time the user data control unit 3 receives the read signal. If the data is the first part of the user data part disassembled from the ATM cell and the pointer value is set in the pointer part of the ATM cell, the pointer value is output to the cell side structured head computing unit 12. .

In the user data control unit 3, the read timing signal output from the user side is input, and the read signal is transmitted to the cell disassembling unit 2 and the cell side structured head computing unit 12 based on the read timing signal. Is output to. As a result, when one octet of user data is input from the cell disassembling unit 2, the user data is output to the user data reading unit 15.

The cell-side structured head calculator 12 is mainly the same as the cell-side structured head instructor 4 in the second embodiment, but when the pointer value is input from the cell disassembly unit 2, The scheduled time when the pointer value becomes 0 is calculated, and when the scheduled time is calculated here, it is output to the structured operation comparison unit 14 as the next cell structured head signal.

The user-side structured head operation unit 13 is mainly the same as the user-side structured head instruction unit 5 in the second embodiment, but the next structured head signal that has not yet been input is actually used. When the scheduled input time of is calculated and the scheduled input time of the next structured head signal is calculated, the scheduled time is output to the structured operation comparison unit 14 as the next user structured head signal.

Structured operation comparison unit 1 of the fifth embodiment
4 mainly has the same function as the fourth embodiment, but further has the same function as the structured match determination unit 6 in the third embodiment. Referring to FIG. If the scheduled time of the side structured head signal is not input, or if the scheduled time of the next user side structured head signal is faster than the scheduled time of the next cell side structured head signal (in case of No1)
Responds to an ATM cell having no pointer portion, the user data reading unit 15 is notified that user data can be output and the scheduled time of the next user side structured head signal is output. When the scheduled time of the signal and the scheduled time of the next user-side structured head signal match (No3
(Corresponding case), and the case where neither the scheduled time of the next cell side structured head signal nor the scheduled time of the next user side structured head signal is input (corresponding to No4), it is the same as the fourth embodiment.

When the scheduled time of the next user-side structured head signal is later than the scheduled time of the next cell-side structured head signal (corresponding to No2), the structured operation comparison of the fifth embodiment is performed. Further, a threshold value is set in advance in the unit 14, and if the time difference between the scheduled times is larger than the threshold value, a notification that the user data cannot be output is given. If it is smaller, the dummy data output is first notified and the scheduled time of the next cell side structured head signal is output, and then the notification of user data output enabled and the scheduled time of the next user side structured head signal is output. Be cut off.

In the user data reading section 15, when the structured data comparing section 14 notifies the user data output is possible and outputs the scheduled time, the user data control section 3 inputs the scheduled time. Preparations for directly outputting the user data to the user data transmitting unit 7 are performed in advance, and when the scheduled time comes, the user data is output to the user data transmitting unit 7 according to the preparation and transmitted to the user side network. Further, if there is a notification that the user data cannot be output and the scheduled time is output, preparation is made in advance to discard the user data input from the user data control unit 3 when the scheduled time comes, and the scheduled time is set. If so, the user data is discarded as prepared and is not transmitted to the user side network. Further, when the dummy data output is notified and the scheduled time is output, the dummy data is read from the dummy data storage unit 10 in advance and is transmitted to the user side network at the scheduled time.

As described above, according to the fifth embodiment, the user data and the pointer value are decomposed from the received ATM cell, and the structured head on the cell side is recognized based on the pointer value. By confirming the match with the structured head signal from the user side and then transmitting the user data to the user side, it is possible to disassemble the ATM cell provided with the pointer and transmit the structured data.

Further, according to the fifth embodiment, the user data can be applied when a plurality of logical channels are multiplexed and each logical channel has an arbitrary structured head.

Furthermore, according to the fifth embodiment, it is possible to know in advance whether or not the structured head signals of both match, so that the processing can be prepared in advance.

Furthermore, according to the fifth embodiment, discarding of user data is minimized even when the structured head signals of both do not match, and it can be applied to an ATM cell having no pointer field. .

(F) Other Embodiments In the first and second embodiments, the case where the user data is discarded when the structured head signals of both do not match has been described. However, the pointer value is not always set in the pointer field. However, the user data may be transmitted when there is no cell-side structured head signal and there is a user-side structured head signal, as in the third embodiment.

In the fourth embodiment, the case where the user data is discarded when the scheduled times of the two next structured head signals do not match has been described, but a pointer value is always set in the pointer field. Therefore, as in the fifth embodiment, the scheduled time of the next cell side structured head signal is not input, or the next user side structured head is shorter than the scheduled time of the next cell side structured head signal. User data may be transmitted when the scheduled time of the signal is fast.

[0101]

As described above, according to the present invention, the received cell is decomposed into user data and a pointer, the structured head is recognized based on the pointer, and the structured head from the user side is recognized. Since the user data is transmitted after confirming the coincidence, the cell provided with the pointer can be disassembled and the user data as the structured data can be transmitted to the user side.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a first exemplary embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a second exemplary embodiment of the present invention.

FIG. 3 is a block diagram showing a detailed configuration of a cell side structured head designating section 4 and a cell side structured number holding section 8 in a second embodiment of the present invention.

FIG. 4 is a block diagram showing a detailed configuration of a user-side structured head designating unit 5 and a TS logical channel conversion table unit 9 according to the second embodiment of the present invention.

FIG. 5 is a block diagram showing a configuration of a third exemplary embodiment of the present invention.

FIG. 6 is a table showing processing conditions of a structured match determination unit 6 according to the third exemplary embodiment of the present invention.

FIG. 7 is a block diagram showing a configuration of a fourth exemplary embodiment of the present invention.

FIG. 8 is a block diagram showing a configuration of a fifth exemplary embodiment of the present invention.

[Explanation of symbols]

1 ... ATM cell receiving unit, 2 ... Cell disassembling unit, 3 ... User data control unit, 4 ... Cell side structured head instructing unit, 5 ... User side structured head instructing unit, 6 ... Structured matching determination unit, 7 ... User data transmission unit.

Continuation of front page (56) Reference JP-A-8-265330 (JP, A) JP-A-8-186586 (JP, A) JP-A-7-99497 (JP, A) JP-A-7-99493 (JP , A) JP-A-9-331329 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) H04L 12/28 H04Q 3/00

Claims (8)

(57) [Claims] 1. A cell disassembling and transmitting method of disassembling cells transmitted from an ATM network at a fixed speed to generate user data which is structured data and transmitting the user data to a user side network. Cell reception disassembly processing that receives the cell transmitted from the cell and disassembles the cell into user data and pointer, and queues the user data disassembled by the cell reception disassembly processing, and queues based on the fixed speed. The structured start position of the user data is determined from the user data read control process for extracting the ingested user data, the pointer decomposed by the cell reception disassembly process and the fixed speed, and the user of the determined structured start position portion is determined. At the same time as the data is retrieved by the user data read control process described above. A cell-side structured head instruction processing for outputting a cell-side structured head signal to the cell-side structured head signal, and a structured head signal from the user side generated based on the fixed speed and the cell-side structured head instruction processing output If the cell-side structured head signal does not match, the user data extracted by the user data read control processing is discarded until the user-side and cell-side structured head signals match next time, and And a structured matching determination control process for sending the extracted user data to the user side network when the structured head signals on the user side and the cell side match. 2. The user data is provided with a time slot for each connection, and the user data of each connection is transferred in the time slot of its own connection. When a cell that is not a slot connection is received, the cell is discarded, and the cell-side structured head indication processing outputs the cell-side structured head signal for each connection, and the structured match determination control processing. Does not match the structured head signal from the user side generated for each connection based on the fixed speed and the cell side structured head signal for each connection output by the cell side structured head instruction processing. In this case, the user is connected until the structured head signals on the user side and cell side of the connection match. The user data of the connection extracted by the data read control process is discarded, and when the structured head signals on the user side and the cell side match, the user data of the connection is sent to the user side network. The cell disassembly and transmission method according to claim 1. 3. The structured coincidence determination control processing, when the user-side structured head signal is not present and the cell-side structured head signal is present, sends dummy data to the user-side structured head signal. When the user-side structured head signal is output within a predetermined period after prompting the signal output, the user data is sent to the user-side network without being discarded, and the user-side structured head signal is not output. Has a dummy data transmission process for discarding user data, and when the user-side structured head signal is present and the cell-side structured head signal is not present, or when the user-side and cell-side structured head signals match. 3. The cell disassembling and transmitting method according to claim 1 or 2, wherein the user data is transmitted to the user side network without being discarded. 4. The cell-side structured start instruction processing calculates in advance the timing at which the user data at the determined structured start position portion is taken out by the user data read control processing, and the result is calculated as the cell-side structured start instruction. It has a cell-side structured head calculation process for outputting as a signal, and the structured matching determination process calculates the timing of the structured head signal output from the user side in advance, and the result is the user-side structured head signal. And a user side structured head calculation signal output by the cell side structured head calculation process and a user side structure output by the user side structured head calculation process. 4. The method according to claim 1, wherein it is determined in advance whether or not the structured head signals of both of them coincide with each other based on the head signal of the structured head. The cell disassembly and transmission method described therein. 5. A cell disassembling and transmitting apparatus for disassembling cells transmitted from an ATM network at a fixed speed to generate user data, which is structured data, and transmitting the user data to a user side network. Cell reception disassembling means for receiving a cell transmitted from the cell and disassembling the cell into user data and a pointer, queuing the user data disassembled by the cell reception disassembling means, and queuing based on the fixed speed. The structured start position of the user data is determined from the user data read control means for extracting the ingested user data, the pointer decomposed by the cell reception disassembly means, and the fixed speed, and the user of the determined structured start position portion is determined. At the same time as the data is retrieved by the user data readout control means A cell-side structured head indicating means for outputting a cell-side structured head signal, a structured head signal from the user side generated based on the fixed speed and the cell-side structured head indicating means If the cell-side structured head signal does not match, the user data fetched by the user data read control means is discarded until the user-side and cell-side structured head signals match next, A cell disassembling and transmitting apparatus comprising: structured coincidence determination control means for transmitting the extracted user data to the user side network when the structured head signals on the user side and the cell side match. 6. The user data is provided with a time slot for each connection, and the user data of each connection is transferred in the time slot of its own connection. When a cell that is not a slot connection is received, the cell is discarded, and the cell-side structured head instruction means outputs the cell-side structured head signal for each connection, and the structured coincidence determination control means. Indicates that the structured head signal from the user side generated for each connection based on the fixed speed does not match the cell side structured head signal for each connection output by the cell side structured head instruction means. In this case, the user is connected until the structured head signals on the user side and cell side of the connection match. The user data of the connection extracted by the data read control means is discarded, and when the structured head signals of the user side and the cell side match, the user data of the connection is sent to the user side network. The cell disassembly / delivery device according to claim 5. 7. The structured match determination control means sends dummy data by sending dummy data when the cell-side structured head signal is present without the user-side structured head signal. When the user-side structured head signal is output within a predetermined period after prompting the signal output, the user data is sent to the user-side network without being discarded, and the user-side structured head signal is not output. Has a dummy data transmission unit for discarding user data, and when the user-side structured head signal is present and the cell-side structured head signal is not present, or when the user-side and cell-side structured head signals match. The cell disassembling and transmitting apparatus according to claim 5 or 6, wherein the user data is transmitted to the user side network without being discarded. 8. The cell side structured head instructing means calculates in advance the timing at which the user data of the determined structured head position portion is taken out by the user data read control means, and the result is the cell side structured head position. The cell-side structured head calculating unit outputs the signal as a signal, and the structured coincidence determination unit calculates in advance the timing of the structured head signal output from the user side, and the result is the user-side structured head signal. And a user-side structure output by the user-side structured head calculation unit, the cell-side structured head signal output by the cell-side structured head calculation unit, and the user-side structure output by the user-side structured head calculation unit. The structured head signal is used to determine in advance whether or not the two structured head signals coincide with each other. On-board cell disassembly / delivery device.