JPH0927808A - Cell assembly / disassembly device - Google Patents

Abstract

(57) [Abstract] [Purpose] To avoid congestion when the ATM network is congested,
A cell assembling / disassembling apparatus for assembling and disassembling a cell is provided. A cell assembly side of a cell assembling / disassembling device for converting fixed bit rate data and ATM cells is provided with means for thinning out data to be transmitted when congestion is detected.
The number of cells input to the M network is reduced, the cell disassembly side is provided with means for complementing the thinned data, and the data is reproduced from the cells input from the ATM network. Then, by reducing the amount of cells input / output to / from the ATM network from the cell assembling / disassembling apparatus, the congestion recovery of the ATM network is accelerated. [Effect] When congestion occurs in the ATM network, the amount of cells to be transmitted to the ATM network can be reduced, the ATM network congestion can be quickly recovered, and the congestion time can be shortened. An ATM network capable of reducing discarded cells can be constructed.

Description

Detailed Description of the Invention

[0001]

The present invention relates to an asynchronous transfer mode (Asy
nchronous Transfer Mode: hereinafter referred to as ATM) The present invention relates to a configuration of a cell assembly and disassembly device (hereinafter referred to as CLAD) for assembling and disassembling cells, and particularly, a synchronous transfer mode (Synchronous Transfer Mode).
ous Transfer Mode: STM) signal and A
Structure of cell assembling / disassembling apparatus suitable for realizing interconnection between STM networks using ATM networks, which is also effective for network congestion control by converting to TM cells, and network congestion control using the same Regarding operation.

[0002]

2. Description of the Related Art In addition to the conventional telephone service for transmitting and receiving voice, as a network for transmitting and receiving high-speed signals (information) of various media such as data and image signals, a broadband service integrated digital network (Broadband Integrated Servic
es Network: hereinafter referred to as BISDN) is becoming widespread, and in this network, communication processing such as transmission / reception and exchange of signals (information) by ATM is performed. The International Telecommunication Union (hereinafter referred to as ITU) has established various recommendations for implementing BISDN. The ITU-
The I 362, I 363, and I 365 of T have a protocol of converting various information as described above into ATM cells corresponding to the characteristics of each information source, that is, an ATM Adaptation Layer (hereinafter referred to as AAL). Functions and specifications are specified. In this AAL protocol, a constant bit rate (Constant Bit Rate) represented by a circuit emulation service:
For services that handle signals (information) of CBR (hereinafter referred to as CBR), type 1 (hereinafter referred to as AAL1) of AAL specified by I363 is to be used. That is, when the STM high-speed digital line data that is CBR data is transmitted through the ATM network, the communication is performed using AAL1.

FIG. 14 shows data of a high-speed digital line using AAL1 and an ATM cell (hereinafter simply referred to as a cell).
3 is a format diagram showing a structure of data of a high-speed digital line and data of each cell, showing a state of conversion with the data of FIG. As shown in the figure, the cell 151 includes an AAL payload (hereinafter simply referred to as a payload) 156 of 46 or 47 bytes for transferring the data 107 of the high speed digital line, and 1 or 2 defined by the AAL1.
Byte AAL header 157 and 5 specified by ITU-T as user / network interface (UNI) or network node interface (NNI).
It is a 53-byte fixed-length packet composed of a byte ATM header 152. In the cell assembly section (sending side),
Cyclic numbers (sequence number: SN) from 0 to 7 are assigned in the sequence number field (SNF) 153 in the order in which the cells 151 are assembled, and the continuity of SNs included in the SNF 153 in the cell disassembly unit (reception side). Cell loss and erroneous insertion are detected by inspecting. In addition, SNF
The value of 153 is protected by a sequence number parity field (SNPF) 154. The pointer field (PF) 155 is an offset 15 indicating the difference between the beginning of the payload and the frame of the high-speed digital line.
9 is indicated, and depending on the value of the SNF 153, this PF 155 may or may not exist. The data 107 of the high-speed digital line is divided into cell units of 46 bytes when the PF 155 exists and 47 bytes when the PF 155 does not exist, and is loaded on the AAL payload 156 as user information, and the above-mentioned SNF153 and SNPF154 and the PF155 added when necessary. AAL header 157 consisting of
And an ATM header 152 are added and transmitted as 151. As described above, in the transmission of the data 107 on the high-speed digital line, since the data 107 continuously comes at a fixed speed and the capacity of the payload 156 of the cell 151 is constant, the amount of cells flowing into the ATM network is Be constant.

An example of a cell assembling / disassembling device (CLAD) for converting various types of data and cells includes:
There is an "ATM cell conversion system" disclosed in Japanese Patent Laid-Open No. 6-97957. This relates to the configuration of an AAL1 cell assembling / disassembling apparatus, which has a means for notifying a channel (time slot) in use in a high-speed digital line in CLAD and transmits only a signal of the channel in use as a cell. Then, as a means for notifying a specific channel in use, the call control signal is analyzed, and while the call is set, the other is considered as not in use and notified. It reduces the flow rate and improves the efficiency of the asynchronous transfer mode network.

On the other hand, ATM is a transmission method that does not depend on media, and the ATM network uses voice, data, and
In addition to AAL1 described above, AAL protocol corresponding to each data (such as variable speed (Variabl
e Bit Rate: hereinafter referred to as VBR) AAL protocol type 3 suitable for communication of data transferred in burst
5: AAL3 and AAL5) are mixed and transmitted. If the signal processed by the ATM network is only CBR data, the cell generation frequency is constant, so that the congestion of the ATM network does not occur unless the bandwidth of the data input to the ATM network exceeds the bandwidth of the network. However, when VBR data is also transmitted through the ATM network, when trying to increase the cell transmission efficiency, that is, when processing as many cells as possible in the network, a large amount of bursty data is generated in the VBR in the network. When it is input to, congestion occurs in which the number of cells in the network exceeds the processing capacity. In order to suppress this congestion, it is necessary to reduce the amount of cells that enter the ATM network when congestion is likely to occur, and to reduce the amount of cells that enter the ATM network when congestion occurs and to quickly recover from the congestion. .

[0006] As an example of congestion control of an ATM network, a journal of the Institute of Electronics, Information and Communication Engineers BI vol.J76-BI No.11 pp.838
"Cell congestion recovery control method in ATM network for high-speed data communication" shown in -848 is known. here,
As a notification method when congestion is detected, BCN (Backward Backward) is used to notify congestion to the originating exchange and the originating terminal from the congestion exchange.
Congestion Notification) method is proposed, and prompt congestion notification and suppression of the amount of cells entering the ATM network are effective for recovery from congestion in the ATM network. Is shown. In this document, the HDLC procedure is used as a protocol for data input to the ATM network. As a feature of the HDLC procedure, data is generated by VBR, there is a margin in the data transfer time that causes congestion, data transfer may be kept waiting, and cell input to the ATM network can be controlled. That is the point. Therefore, in data transfer using the HDLC procedure, it is possible to temporarily buffer data when congestion occurs and reduce the amount of data entering the ATM network. In view of this, in the same document, by buffering data for data transmission using the HDLC protocol, the flow rate of cells is temporarily reduced to recover from congestion.

[0007]

When data of a high-speed digital line is transferred using an ATM network, continuous data having a high real-time property is transferred from the high-speed digital line. Therefore, data transfer using the above-mentioned HDLC protocol is performed. It is not possible to temporarily buffer data as in. That is, even if the congestion notification is given to the data on the high-speed digital line, continuous data with high real-time property needs to be sequentially converted into cells and transferred, so that the ATM network is temporarily buffered. The amount of cells cannot be reduced. Therefore, in the above-mentioned Japanese Patent Laid-Open No. 6-97957, the ATM is reduced by reducing the cell amount without transmitting the unused channel of the high-speed digital line.
Improves network efficiency, but if all channels of the high-speed digital line are used and there are no unused channels, the cell amount cannot be reduced, and even if congestion notification is received, unused cells are not used. Since the cell amount cannot be reduced until the number of channels increases, it cannot be said to be sufficient as a means for congestion recovery when congestion occurs in the ATM network.

The ATM network accommodates and processes data of various media such as CBR data and VBR data. In such a network, the rate at which cells corresponding to data of media having various properties are input and processed varies depending on the installation location and time of use of the network. Looking at the introduction form, AT
The M network is a network that has just been introduced, and there are many STM networks. In the future, the ATM network will be configured to connect (accommodate) these existing STM networks. That is, CBR
Even in a network in which data of various media such as data and VBR data are mixed, it is difficult to reduce the cell amount in order to avoid congestion, and a large proportion of cells of CBR data are input, thus increasing the capacity of the network. Unless otherwise provided, cells such as VBR data, which can temporarily reduce the cell flow rate by buffering the data to be transmitted, become a network configured to reduce the cell amount in order to avoid congestion of the entire network. There are cases. In view of the use of communication services using VBR data, this is likely to cause congestion even though it is a network that can handle high-speed and wideband signals, resulting in a long cell transmission waiting time for avoidance and cell discard. BISD, such as increase in number, time required for information transfer, etc.
The net is not easy to use because the characteristics of N cannot be utilized.

Therefore, an AT for accommodating and processing data of various media such as CBR data and VBR data
In the M-switched network, a means for temporarily reducing the cell flow rate without buffering is also provided for high-speed digital line data so as to improve transmission efficiency and prevent congestion, and CBR data, VBR data, etc. It is desirable that the ATM network can efficiently transfer data of various media and can easily recover in a short time even when congestion occurs.

An object of the present invention is to eliminate the above-mentioned problems and to process data of various media in a mixed manner.
The purpose of the present invention is to realize an ATM switching network capable of handling various data such as CBR data and VBR data at an appropriate ratio in a TM switching network and performing efficient cell processing. Further, when congestion occurs in the ATM switching network, the cell amount of the cells transmitting the CBR data is reduced in addition to the cells transmitting the VBR data, and the ATM switching network can recover the congestion quickly. It is to realize an ATM switching network. And to realize these switching networks,
An object of the present invention is to provide a cell assembling / disassembling apparatus capable of reducing the cell amount so that even in the case of CBR data, the buffering is not performed and the real-time property is not impaired at the time of congestion. Further, when congestion occurs in the ATM switching network, the subscriber terminal is notified that congestion has occurred, and the subscriber side controls the data transfer so as to avoid congestion, which is complicated and time-consuming for the subscriber. It is an object of the present invention to provide a cell assembling / disassembling apparatus capable of avoiding congestion at high speed with a simple configuration, which can detect congestion and perform avoidance processing only by the equipment in the ATM network without performing such congestion control. More specifically, without a high-performance device such as a voice compression encoding device, at the time of congestion, it is possible to reduce a part of the CBR data to reduce the cell amount, a simple configuration, economical, and An object is to provide a cell assembling / disassembling apparatus whose operation control is easy.

[0011]

The CBR data, which is transmitted mainly through a high-speed digital line, is mainly a voice signal. In the high-speed digital line, if the time slot (TS) in the frame is the same, the destination of the data does not change, and the voice signal is a continuous signal and is sampled due to its correlation and redundancy. Even if the data changes slightly and noise is generated, conversation is possible.

Therefore, as means for solving the above problems,
Means for assembling cells by thinning out data on the transmitting side (cell assembling side) of the cell assembling / disassembling device for converting data and cells of the high-speed digital line of the present invention, and the receiving side of the cell assembling / disassembling device (cell disassembling side). ) Is provided with a means for decomposing cells and complementing thinned data, and when congestion notification from the ATM network is detected, data is thinned and the amount of cells input to the network is reduced so that congestion can be recovered.

More specifically, on the cell assembling side, the TS and the number of bits to be thinned out in the TS are selected from the data of the TS of the high-speed digital line according to a predetermined rule, and the bits (data) of the TS are thinned out to make the cell. And a means for complementing the bits on the cell disassembling side by the bits thinned out on the assembling side to reproduce the data on the high-speed digital line.

Alternatively, on the cell assembling side, after converting the data of the high-speed digital line into cells, the cells are selected according to a predetermined rule, and the means for thinning out the data in cell units and the number of thinned cells are added to the cell header. A means for advancing the included sequence number to give a sequence number to the cell and a means for compensating the cell disassembly side with cell-unit data of the number of the skipped number when the sequence numbers of the received cells are not continuous , I tried to play the data on the high-speed digital line.

Alternatively, on the cell assembling side, a cell is selected according to a predetermined rule, the data is thinned out from the data of the high-speed digital line in cell units to assemble the cell, and the cell disassembling side is set at the set time. When a cell is not received, a means for complementing cell-by-cell data is provided to reproduce the data on the high-speed digital line. In each of the above configurations, the cell assembling side thins out the data to reduce the amount of cells to be transmitted through the ATM network, and the cell disassembling side uses the same amount of data for transmission and reception, and the same data configuration for the high-speed digital line is used for transmission and reception. It is configured to be kept at.

Further, as means for solving the above problems,
In the cell assembling / disassembling apparatus for converting the data of the high-speed digital line and the cell of the present invention, the transmitting side (cell assembling side) and the receiving side (cell disassembling side) normally perform cell assembling and disassembling, respectively. (Normal mode) and when congestion occurs, the assembly side thins the data to reduce the amount of cells transmitted on the ATM network,
It is equipped with a state (congestion mode) in which cells are assembled and disassembled in a congested state in which data is complemented on the disassembly side. When network congestion is detected, the normal mode is transferred to the congested mode and the ATM is transferred.
When the congestion of the network is detected by reducing the amount of cells transmitted in the network and the release of the congestion of the network is detected, the normal mode is set and the cell is assembled and disassembled. Also, the transmission side (cell assembly side)
And the receiving side (cell disassembling side) are provided with means for notifying the switching of the mode between the assembling side and the disassembling side so that the above two normal modes and the congestion mode are synchronously transitioned. The configuration is such that there is no inconsistency in the conversion operation between line data and cells.

The ATM network is equipped with the cell assembling / disassembling apparatus, which also transfers CBR data, which is transmitted using a high-speed digital line, and when the network congestion occurs, the cell assembling / disassembling apparatus is used. Also, the CBR data is not buffered and the congestion is recovered by the configuration and operation of reducing the cell amount so as not to impair the real-time property.

[0018]

By providing the above means, the amount of cells entering the ATM network can be reduced and the congestion can be restored by the means for thinning out the data on the transmitting side. However, on the transmitting side, the amount of data is thinned out, and the amount of data in one frame decreases, so that the cycle of one frame becomes shorter.
Therefore, the means for complementing the data thinned out on the receiving side complements the missing data, so that the data structures on the transmitting side and the receiving side can be made the same.

Alternatively, the amount of cells that enter the ATM network is reduced by the number of cells thinned by the means for thinning cells on the transmitting side, and congestion can be recovered. However, since the receiving side knows that the sequence numbers are skipped and the data is thinned out by the amount of the sequence number skipped, the thinned-out data can be complemented. That is, by complementing the thinned-out data, it is possible to make the data configurations of the transmitting side and the receiving side the same.

Further, by thinning out data on a cell-by-cell basis on the transmitting side, the number of cells that enter the ATM network is reduced by the number of thinned-out cells and congestion can be restored. In the case of CBR data, the cycle at which cells arrive at the receiving side is almost constant, but the cell arrival cycle becomes longer by the amount of data thinned out at the transmitting side during congestion. Therefore, when the cell arrival period is set in advance and the set time cell is not received, the data structure on the transmission side and the reception side can be made the same by complementing the data in cell units.

Due to the above-mentioned characteristics of the voice signal, even if the cell assembling / disassembling apparatus thins out and complements the data, the sampled data is slightly changed to generate noise, but conversation is possible. Of course, because it is configured to perform data thinning and complement only when congestion occurs,
In the normal state, the quality of the voice signal does not deteriorate. In addition, the data is thinned and complemented with a simple structure, and LD-
A high-performance voice signal compression device typified by CELP is not necessary, and congestion can be recovered by performing data thinning and complementing only during congestion with an economical configuration. Further, since the cell assembling side and the disassembling side operate in synchronization, the data at the normal time is not erroneously thinned out or supplemented, and the data structure of the transmitting side and the receiving side are the same. can do.

In the ATM network, by providing the cell assembling / disassembling apparatus according to the present invention, when congestion occurs, the amount of cells can be reduced and the congestion recovery operation can be performed even with CBR data. In order to avoid congestion in the entire network, the amount of cells is not reduced, and both can appropriately reduce the number of cells to perform the congestion recovery, so that the congestion recovery becomes faster and the cell discard during the congestion can be reduced. Moreover, even if the generation of congestion is not notified to the terminal on the subscriber side which is the data generation source, if the cell assembling / disassembling apparatus according to the present invention is notified of the occurrence of congestion, the congestion avoiding operation is executed there. That is, A that processes data of various media in a mixed manner
In the TM switching network, efficient cell processing can be performed for both users of CBR data and VBR data, congestion recovery can be speeded up, cell discard during congestion can be reduced, and special congestion control for subscriber terminals is possible. It is possible to provide an easy-to-use ATM network that makes use of the characteristics of BISDN with a simple structure without providing any operation or equipment.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a cell assembling / disassembling apparatus according to the present invention and an embodiment of ATM network congestion control using the same will be described below in detail with reference to the drawings. FIG. 1 shows an ATM using a cell assembling / disassembling apparatus (CLAD) according to the present invention.
It is a network block diagram which shows the structure of a communication network. In the figure, the cell assembly unit 101a of CLAD uses the data from the high-speed digital line 107a as a cell 151 to form an ATM.
Congestion notification receiving means 103 for transmitting to the network 106, and receiving a message when the ATM network 106 is congested.
By knowing the congestion, the means 104 for thinning out data thins out the data from the high-speed digital line 107a. After thinning out the data, the cells are assembled by the cell assembling means 105 and the cell 151 is transmitted to the ATM network 106. Also, CLA
The cell disassembling unit 101b of D receives cell 1 from the ATM network 106.
After receiving 51, the cell disassembling means 109 disassembles the cell 151 and transmits the data to the high-speed digital line 107b. When the ATM network 106 is congested, the congestion notification receiving means 108 receives the message. Know the congestion,
The data complementing means 110 adds dummy data corresponding to the data thinned out in the cell assembling unit 101a and transmits the data to the high-speed digital line 107b.

FIG. 2 is a sequence diagram showing a congestion processing sequence when the network of FIG. 1 is congested. This sequence is used when congestion occurs in the ATM network 106.
By limiting the amount of cells input to the ATM network 106, it is possible to speed up recovery from the congestion state, and the cell assembling unit 101a receives the congestion notification 205 to send the AT.
Knowing that congestion has occurred in the M network 106, the normal mode 2
From 01a to the congestion mode 202, data is thinned out to reduce the cell amount to recover from the congestion state.
Further, the congestion notification 205 is periodically (in the present embodiment,
Cell assembly unit 101a.
Knows that the congestion notification 205 is no longer present and recovery from congestion is achieved. The cell assembling unit 101a returns from the congestion mode 202 to the normal mode 201b when it knows the recovery from the congestion,
It works to stop thinning data and reducing the amount of cells. Further, the cell disassembling unit 101b uses the ATM network 106.
When the congestion notification 205 is received from the normal mode 203a
To the congestion mode 204, and data is complemented.
Then, similarly to the cell assembling unit 101a, when the recovery from the congestion is known, the congestion mode 204 returns to the normal mode 203b, and the data complementation is stopped.

The congestion notification 205 from the ATM network 106
Causes the CLAD (101a, 101a)
Each of b) is in the normal mode (201a, 201b,
203a, 203b) and congestion mode (202, 204)
When the modes are switched between the two modes, the CLAD (101a, 101b) processing on the transmission side and the reception side cause inconsistency due to the timing shift between the modes and the cell arrival delay. For example, in the figure, the cell 151j generated in the normal mode on the transmission side is a cell that is transmitted by the cell assembling unit 101a and does not thin out data, but is received on the reception side after the congestion mode 204 is reached. Because
The cell disassembling unit 101b determines that a cell from which data has been thinned has been received, and complements the data when converting the cell into data. Therefore, the CLAD of the present invention
Then, CLAD (101a, 101a) of the transmission side and the reception side
Since a means for adjusting the timing of mode switching is required in b), this means will be described below. FIG.
FIG. 6 is a sequence diagram showing a network congestion processing sequence using the mode switching notification cell 206 according to the present invention. The cell assembling unit 101a on the transmission side receives the congestion notification 205 from the ATM network 106, switches the mode to the congestion mode 202, and transmits the mode switching notification cell 206 before transmitting the next cell 205j. In the cell disassembling unit 101b on the receiving side, the mode switching notification cell 2
When 06 is received, the mode is switched to the normal mode 203a, 203b or the congestion mode 204. In the present embodiment, the mode switching notification cell 206 has a specific pattern A
A cell having an AL header 157 was used. In particular,
A normal cell 151 is added to the PF 155 of the AAL header 157.
A cell having a value (a value of 93 or more that exceeds the number of bytes of the payload 156) exceeding a range that represents an offset, which is an impossible value, is used as the mode switching notification cell 206. Mode switching notification cell 206
Is different only in the value in the PF 155, and the ATM network 10
The handling in 6 is the same as the cell 151 that transmits data. Therefore, the order of arrival of cells is guaranteed, and the receiving side can switch the mode after receiving the cell after the mode switching on the transmitting side.

FIG. 4 is a block diagram showing the configuration of the cell assembling / disassembling apparatus (CLAD) according to the present invention. The CLAD 901 of the present invention is a combination of the cell assembling unit 101a on the transmitting side and the cell disassembling unit 101b on the receiving side of the CLAD shown in FIG. 1, and transmits the data of the high-speed digital line 107a into the cell 151 to the ATM network 106. And also ATM
The cell 151 received from the network 106 is converted into data and transmitted to the high-speed digital line 107b. The AAL type 1 cell 151 conforming to the ITU-T recommendation is assembled and disassembled. First, the configuration and operation on the cell assembly side in the normal mode 201 (FIG. 2) will be described with reference to the format diagram shown in FIG. Line terminator (TPH
Y) 902 terminates the frame of the high speed digital line 107a. The transmission side control unit (TCTL) 904 is a TPH.
The data of the terminated high-speed digital line 107a is transferred to the signal line 92 in accordance with the frame signal 921 from the Y902.
Transmit memory (TMEM) 9 assigned via 0
Control to write in the signal line 922.
Supplied from). Here, TCTL904 is TME
When data is written to the M903 via the signal line 920,
When a built-in counter means (not shown) is counted up and data is read from the TMEM 903, the count means is counted down to manage the amount of data in the TMEM 903, and the amount of data that can be transmitted for one cell (main In the embodiment, when 46 bytes or 47 bytes are written, the cell assembly unit (ASSM) 907 is read from the TMEM 903.
The control for reading out the data 156 is performed. The transmission side ATM header holding unit (TATM) 90 of the CLAD according to the present embodiment.
5 includes an ATM header 15 defined by the ITU-T recommendation.
2 As information, the VP corresponding to the side receiving the cell 151
Information such as I and VCI is given in advance at the start of call processing from a call processor (not shown) or the like. The TATM 905 transmits the ATM header 157 to the ASMS 907 according to the control signal 924 from the TCTL 904. Also, the sender AAL header holding unit (TAA
L) 906 has a circuit for generating and holding the AAL header 157 shown in FIG. 14, and generates the AAL header 157 by the control signal 923 from the TCTL 904 to generate the ASMS.
Send to 907. Specifically, a cyclic number from 0 to 7 (sequence number: SN) is added to the SNF 153 of the AAL header 157, a cyclic code (CRC code) for error protection of the SNF 153 is added to the SNPF 154, and the PF 155 is included in the AAL payload. Data 156 and the offset value 159 between the start position of the frame of the high-speed digital line 107a are added. ASME907 is TME
Data 156 from M903 and A from TATM905
The ATM header 152 and the AAL header 157 from the TAAL 906 are combined to generate the cell 151, and the ATM 151 is generated.
The cell is transmitted to the network 106.

Next, the structure and operation of the cell disassembly side in the normal mode 201 (FIG. 2) will be described with reference to the format diagram shown in FIG. Cell disassembly unit (DIS
Upon receiving the cell 151 from the ATM network 106, the ASS) 910 stores the ATM header 157 in the receiving side ATM header holding unit (RATM) 911, the AAL header 152 in the receiving side AAL header holding unit (RAAL) 912, and the AAL payload. Data 156 is received in memory (RMEM) 91
4 respectively. Similar to the cell assembling side, the RATM 911 has a configuration in which the value of the ATM header is registered in advance. The ATM header 157 of the receiving cell 151 is compared with the registered value, and if the contents match, reception is performed. The cell reception signal 934 is transmitted to the side controller (RCTL) 913. This RATM 911 is R when the ATM header 157 has an error and has a value that is not registered.
The cell reception signal 934 is not transmitted to the CTL 913. RAAL912 is an SN from 0 to 7 of SNF153.
Is received, the continuity of the numbers is checked, and when a cell loss is detected, a cell loss notification 935 is transmitted to the RCTL 913. Also, an offset value 159 indicating the beginning of the frame
Is read from PF155 and notified to RCTL913 935
I do. The RCTL 913 notifies the cell loss signal 931 from the RATM 911 and the cell loss notification 9 from the RAAL 912.
35, the control signal 938 controls the writing and reading of data to and from the RMEM 914. Furthermore, RCT
The L913 generates a frame signal 936, and controls the RME by the control signal 938 so that the data indicated by the offset value 159 is at the head of the frame of the high-speed digital line.
Control to read data 937 from M914 to RPHY915 is performed. The RPHY 915 is a frame signal 936.
A frame is generated in accordance with the above, the data is placed on the frame, and the data is transmitted to the high-speed digital line 107b.

Next, the cell assembling / disassembling apparatus (CLA) of the present invention.
The operation in the congestion mode of D) will be described in detail with reference to the drawings. The main data transmitted by the high-speed digital line 107 is a voice signal. This audio signal is a continuous signal, and the correlation and redundancy between signals are large, so even if the amount of data to be transmitted is reduced,
Although the quality is deteriorated, it is possible to talk between the sender and the receiver. Therefore, in the cell assembling / disassembling apparatus (CLAD) of the present invention, in the cell assembling apparatus (FIG. 1, 101a and FIG. 9, 901) for assembling the cells, in normal time (when operating in the normal mode described above). , All the data from the high-speed digital line is made into cells and put into the ATM network, but when the ATM network is congested, it operates in the congestion mode focusing on the characteristics of the voice signal described above, Congestion is avoided by thinning out data from the high-speed digital line according to a predetermined rule, such as thinning out (TS) data, to generate cells and reducing the number of cells to be put in the ATM network. In addition, a cell disassembly device for disassembling the cell (see FIGS. 1 and 101b and FIGS. 9 and 9).
In 01), the data from the high-speed digital line is
When the data is thinned out on the assembly side, the data thinned out at the time of cell disassembly is complemented to reproduce the data on the high-speed digital line. It should be noted that the rule of thinning out data, such as designation of TS for reducing data, uses a call processor (not shown) or the like in advance so that the quality of the audio signal allowed by the system or the user of the system is maintained. It is configured to be set between the cell assembling / disassembling devices at the time of initial setting or call processing.

As described above, the cell assembling / disassembling apparatus (CLAD) of the present invention has a configuration and operation for reducing the number of cells of AAL1 and a configuration for complementing the reduced data in order to avoid network congestion. An example showing the operation,
Hereinafter, a detailed description will be given with reference to the drawings. FIG. 5 is an operation explanatory view on the CLAD assembling side showing a state in which the cell assembling / disassembling apparatus (CLAD) of the present invention thins out the bits of the data of the high-speed digital line and converts them into cells in the congestion mode. In this embodiment, the TS1 of the high speed digital line 107a is used.
And TS2 are placed in the same cell for transmission. In the congestion mode, the high-speed digital line 107a is shown.
The operation on the CLAD assembling side for reducing the number of cells input to the ATM communication network by thinning out the bits of each TS of FIG. Specifically, in the congestion mode, the CLAD assembling side puts the 4 bits 301 and 303 from the upper bit (MSB) in each TS of the data of the high-speed digital line 107a on the AAL payload 156 of the cell 151 and This is to assemble the cells of AAL1 by discarding the 4 bits 302 and 304 from the lower bit (LSB).

Further, FIG. 6 shows how the cell assembling / disassembling apparatus (CLAD) of the present invention complements the data obtained by disassembling the cells in the congestion mode and converts the data into high-speed digital line data. FIG. 6 is an operation explanatory diagram, showing a state of complementing data corresponding to the thinning out of the data, which is described above and in FIG. 5. CL of the present invention
In the congestion mode, the AD decomposition side uses the CL shown in FIG.
When the cell 151 from which data has been thinned on the AD assembly side is received, from the beginning of the AAL payload 156 of the cell 151,
The data corresponding to each TS is read out as 4 bits of 301 and 303, and is set as the upper bit (4 bits from MSB) of each TS, and the dummy data 305 and 306 is added to the lower bit (4 bits from LSB) of each TS. Each one
The data is for one TS.

FIG. 7 is a detailed explanatory diagram showing a partial configuration and operation of the CLAD of the present invention for carrying out the above-described data thinning and complement, and a detailed description of the CLAD of the present invention using a block diagram and a timing chart. The configuration and operation will be described. The block configuration diagram of this figure is a part of the block configuration diagram of the CLAD of the present invention shown in FIG. 4, and the reference numerals and abbreviations are the same as those in FIG. On the cell assembly side, when the TCTL 904 receives the congestion notification from the ATM network (205 in FIG. 2), the TMEM 90 outputs only the upper 4 bits of each TS of the output data 920 of the TPHY 902.
The control signal 922 for controlling the writing to the
Send to M903. As a result, as shown in FIG.
The upper 4 bits are extracted from the MSB of the data of each TS, and L
The lower 4 bits from SB are discarded, that is, the thinned data is input to TMEM903. Therefore,
Only the thinned data is input to the payload 156 of the cell 151, converted into the AAL1 cell, and the AT
It is transmitted to the M network 6.

On the other hand, on the cell disassembly side, RCTL91
3 is data 93 from RMEM914 to RPHY915.
7 is read, but the data 93
When the data of 7 is read, the data in the RMEM 914 is insufficient by the amount of data thinned on the transmitting side. Therefore, at the time of congestion, TS1 indicated by the offset value 159 of the PF 155
The upper 4 bits of are read and the reading is stopped 4 times.
As shown in the time chart of the read signal 938 of FIG. 7, this is because the RMEM read signal 938 of a form in which the transmission of the transmission pulse is continuously transmitted for 4 pulses and then the transmission of the pulse for 4 pulses is stopped from the RCTL 913. It is performed by transmitting to RMEM914. RPHY914 is RMEM9
The data 937 from 14 is always read and output to the high speed digital line. Therefore, while the reading from the RMEM 914 is stopped, the last read data is output, and the value of the 4th bit data is the dummy data 305 of the lower 4 bits of TS. The same applies to the data output of the high-speed digital line after TS2.

According to the operation of the CLAD of the present invention as described above, the data to be transmitted can be halved by thinning out 4 bits from the lower bit of the voice signal at the time of congestion, and the number of cells to be transmitted can be reduced. It can be reduced to 1/2.
Further, if the audio data is data sampled by μ-low, even if only 4 bits are selected from the MSB as described above, the audio signal continuously changes, and the volume of the calling side and When the pronunciation content changes suddenly, unclear voice will be sent for a moment at the beginning or end of the word.
In normal conversation, the LSB of the sampled signal
Since only the part showing the fluctuation of the fine voice level on the side is deleted, the other party can hear and recognize the voice of the speaker by the continuity of the voice signal and the correlation and redundancy of information. That is, communication with the other party by a voice signal will not be disabled. That is, according to the CLAD of the present invention, it is possible to realize an ATM communication network capable of efficiently processing data having various properties such as voice and data while avoiding network congestion, although some voice quality deterioration occurs. Further, since the CLAD of the present invention performs the congestion avoidance operation without notifying the terminal on the subscriber side of the occurrence of congestion, a device for special congestion avoidance is provided in the terminal of the subscriber who handles fixed speed data. In addition, the subscriber does not need to perform congestion avoidance control, and an ATM communication network with an economical configuration that allows existing terminals to be used as is can be realized.

In the above embodiment, the method of deleting 4 bits of each TS signal in order to halve the cell transmission amount has been described. However, the amount of data to be thinned out is determined in advance on the transmitting side and the receiving side. The number of bits to be deleted can be changed by the same method as described above. Further, the same operation is possible even if the number of TSs from which data is thinned out or the number of TSs to be transmitted in the same cell is changed or set.

FIG. 8 shows a cell assembling / disassembling apparatus (CL of the present invention.
AD) shows the operation of another embodiment on the cell assembling side, showing a state in which the bits of the data of the high-speed digital line are thinned out and converted into cells in a configuration different from the above-mentioned embodiment in the congestion mode. It is an explanatory view of the operation. In the figure, the above embodiment shows that each TS (or a specific T
S) data is thinned out, whereas a specific cell is thinned out in cell units to reduce the amount of cells to avoid congestion. The number of cells thinned out in cell units and thinned out is shown. It shows the operation of advancing and adding the SN input to the SNF 153, assembling the cell and transmitting the cell to the ATM network. Specifically, in the congestion mode, CLAD
The assembling side sequentially divides the high-speed digital line data 107a into data blocks A, B, C, D, and E for one cell unit (46 bytes or 47 bytes), and assembles these into cells 151, respectively. At this time, the value of SN is 1 for cells containing A data, 2 for cells containing B data, hereafter C is 3, D is 4, and E is 5. Here, in order to avoid congestion, according to a rule previously set between the transmission and reception CLAD, in the present embodiment, the cell 151c whose SN for transmitting the data C is 3 is discarded (501). This reduces the number of cells transmitted to the ATM network by one cell.

Further, FIG. 9 shows another state of the CLAD disassembling side showing how the cell assembling / disassembling apparatus (CLAD) of the present invention complements the cell data and converts it into high-speed digital line data in the congestion mode. FIG. 9 is an operation explanatory diagram, showing how data is complemented in accordance with the thinning out of the data described above and in FIG. 8. In the congestion mode, the CLAD disassembling side of the present invention has a cell 151b with an SN of 2.
Then, the cell 151d having an SN of 4 arrives, so it is understood that one cell has not been sent. That is, it can be seen that in the congestion mode, the cell 151c whose SN is 3 is discarded on the CLAD assembling side. Here, dummy data 601 is provided only for the data (deficient data) sent in the cell whose SN is 3.
Is inserted (complementary) between the data blocks B and D to reproduce high-speed digital line data. Of course, data C
This is the dummy data 601, and a bit change occurs at the time of transmission, but the frame structure of the high-speed digital line data 107b can be restored to the same as that on the transmission side.

FIG. 10 is a detailed explanatory view showing another partial configuration and operation of the CLAD of the present invention for carrying out the above-described data thinning and complementation. The CLAD of the present invention will be described using a block configuration diagram and a timing chart. The detailed configuration and operation will be described. The block diagram of this figure is also shown in FIG.
4 is a partial block diagram of the CLAD block diagram of the present invention shown in FIG.
Is the same as On the cell assembly side, TCTL904
Sends a TATM transmission request 924 to TATM 905, TA
TAAL transmission request 923 to AL906, TMEM90
3 sequentially transmits the TMEM transmission request signal 922 to each of the cells for assembling the data to the ASMS 907. The ASMS 907 receives each data and assembles a cell. Here, when the TCTL 904 receives the congestion notification, the TCTL 904 sends a cell 1 with an SN of 3 to the ASMS 907.
A cell discard request signal 925 for discarding 51c is transmitted. The ASMS 907 performs cell discard 501.
Instead, the empty cell 502 is transmitted. That is, by discarding the cell, the AA carrying the data that the SN has captured
L1 valid cells will be transmitted to the ATM network.

On the other hand, on the cell disassembly side, RAAL91
No. 2 monitors that the SNs of the arriving cells are continuous, and when detecting that the SN has stopped, it transmits a sequence number error signal 935 to the RCTL 913. RC
The TL 913 controls the RMEM 914, and stops writing the next data whose SN continuity is interrupted. The RCTL 913 also controls the RMEM 914, and stops the transmission of the RMEM read signal 938 before reading the RMEM 914 to stop the reading of data for one cell. The RPHY 915 sends the data 937 from the RMEM 914 in a frame and transmits it.
Even when data does not come from 914, the dummy data signal 951 is continuously placed on the frame and transmitted. The dummy data 951 is the data 9 of the RMEM 914 and the RPHY 915.
If the signal level of 37 is H, 1 is inserted, and if L, 0 is inserted.

According to the CLAD operation of the present invention as described above, by discarding a predetermined cell at the time of congestion, A
Congestion can be avoided by reducing the number of cells input to the TM communication network. Even if only a specific cell is deleted as described above, from the viewpoint of the receiving side, 1 to several bytes of data are erroneously or omitted from the audio signals arriving consecutively for each TS. , Click noise is generated in the voice signal, but the continuity of the voice signal and the correlation and redundancy of information allow the other party to hear and recognize the voice of the speaker. That is, communication with the other party by a voice signal will not be disabled. That is, the C of the present invention
According to LAD, although some voice quality deterioration occurs,
It is possible to realize an ATM communication network capable of efficiently processing data having various properties such as voice and data while avoiding network congestion.

Further, in the above embodiment, the method of deleting one cell in order to reduce the transmission amount of cells has been shown. However, the amount of data to be thinned out can be determined in advance on the transmitting side and the receiving side. By the same method, the number of cells to be deleted and the deletion cycle can be changed.

FIG. 11 shows a cell assembling / disassembling apparatus (C
LAD) shows the operation of another embodiment on the cell assembling side in which the bits of the data of the high-speed digital line are thinned out and converted into cells in a configuration different from the above-mentioned embodiment in the congestion mode. It is an explanatory view of the operation. This embodiment utilizes the delay of the cell arrival time by thinning out the data in cell units, whereas the previous embodiment selected and discarded a specific cell after cell assembly. Data block A, B, C of high-speed digital line for one cell unit
When D and E are sequentially assembled in the cell 151, the data of the data block C corresponding to the cell whose SN is 3 is discarded (701) before the cell assembly, as shown in the same example as the previous embodiment. . When data of C is discarded due to occurrence of congestion, cell 151b carrying data B and cell 1 carrying data D
The cell transmission interval with 51f is increased by one cell excluding C, and the cells are transmitted to the ATM network with the cells reduced.

FIG. 12 shows another state of the CLAD disassembling side showing how the cell assembling / disassembling apparatus (CLAD) of the present invention complements the cell data and converts it into high-speed digital line data in the congestion mode. FIG. 12 is an operation explanatory diagram, and shows a state of complementing data in accordance with the thinning out of the data described above and in FIG. 11. CLA of the present invention
On the D decomposition side, the transferred cell is A with a fixed bit rate.
Since the cell is an AL1 type cell, the cell arrives almost periodically (period Td in this embodiment), but in the congestion mode, after the cell 151b carrying the data B arrives,
For about Td, the cell does not come when the next cell should arrive. In this case, the CLAD decomposition side puts dummy data for one cell. Then, since the cell 151f carrying the data D arrives at the next cell arrival timing, the bit of the data C changes from the time of transmission due to the dummy data, but the frame structure of the high-speed digital line 107b is the same as that of the transmission side. Can be restored to the same one.

FIG. 13 is a detailed explanatory view showing another partial configuration and operation of the CLAD of the present invention for carrying out the above-described data thinning and complementation. The CLAD of the present invention will be described with reference to a block diagram and a timing chart. The detailed configuration and other operations will be described. In addition, the block diagram of this figure also
Similar to FIG. 7 and FIG. 10, the CL of the present invention previously shown in FIG.
A part of the block diagram of AD is extracted, and the reference numerals and abbreviations are the same as those in FIG. On the cell assembly side, TC
The TL 904 sends a TATM transmission request 92 to the TATM 905.
4, a TAAL transmission request 923 to the TAAL 906, T
The TMEM transmission request signal 922 is transmitted to the MEM 903 in order, and the respective data for assembling the cell is sent to the ASMS.
907 to send. Then, the ASMS 907 receives each data and assembles a cell. Where T
Upon receiving the congestion notification, the CTL 904 sends a TATM transmission request signal 924 to the TATM 905 and TAAL to the TAAL.
The transmission of the transmission request signal 923 and the TMEM transmission request signal 923 to the TMEM 903 is stopped. As a result, ASS
The M907 transmits cells to the ATM network in the form of inserting empty cells between the valid cells of AAL1 carrying the data B and D, respectively.

On the other hand, on the cell disassembly side, DISASS
910 monitors the cell arrival period (Td) and transmits a cell arrival delay signal 931 to the RCTL 913 when the cell arrival interval becomes long. RCTL913 is the same as RMEM914
When the cell arrival delay signal 931 is received, the transmission of the RMEM read signal 938 is stopped and the reading of data for one cell is stopped before reading the RMEM 914. The RPHY 915 sends the data 937 from the RMEM 914 in a frame and transmits it.
Even when the data does not come from 914, the dummy data 951 is continuously put on the frame and transmitted. Dummy data is R
If the signal level of the data 937 of MEM 914 and RPHY 915 is H, 1 is inserted, and if L, 0 is inserted.

According to the CLAD operation of the present invention as described above, by discarding predetermined block data at the time of congestion, it is possible to reduce the number of cells input to the ATM communication network and avoid congestion. Even if only specific block data is deleted as described above, from the viewpoint of the receiving side, only one byte to several bytes of data will be erroneous or omitted from the audio signals arriving consecutively for each TS. Therefore, although click noise is generated in the voice signal, the voice of the speaker can be heard and recognized on the other side due to the continuity of the voice signal and the correlation and redundancy of information. That is, communication with the other party by a voice signal does not become impossible. That is, according to the CLAD of the present invention, it is possible to realize an ATM communication network capable of efficiently processing data having various properties such as voice and data while avoiding network congestion, although some voice quality deterioration occurs.

In the above embodiment, the method of deleting one data block in order to reduce the cell transmission amount is shown. However, the amount of data to be thinned out can be determined in advance on the transmitting side and the receiving side. By the same method, the number of data blocks to be deleted and the deletion cycle can be changed.

[0047]

According to the present invention, when congestion occurs in the ATM network, the amount of cells transmitted to the ATM network can be reduced, and recovery from congestion in the ATM network becomes faster. By shortening the congestion time, it is possible to reduce discarded cells due to congestion. Therefore, even in an ATM network that processes various types of data by converting them into cells, an efficient ATM network that can perform high-speed communication processing with fast congestion recovery, few discarded cells, and low data transmission wait time is provided. Can be built.

[Brief description of drawings]

FIG. 1 is a network configuration diagram showing a configuration of an ATM communication network using a cell assembling / disassembling apparatus of the present invention.

FIG. 2 is a sequence diagram showing a congestion processing sequence of the ATM network shown in FIG.

FIG. 3 is a sequence diagram showing congestion processing of an ATM network using a mode switching notification cell according to the present invention.

FIG. 4 is a block diagram showing the configuration of a cell assembling / disassembling apparatus according to the present invention.

FIG. 5 is an operation explanatory view showing an operation example of the cell assembling side of the cell assembling / disassembling apparatus of the present invention.

FIG. 6 is an operation explanatory view showing an operation example on the cell disassembly side of the cell assembling / disassembling apparatus of the present invention.

FIG. 7 is a detailed explanatory view showing a detailed partial configuration and operation of the cell assembling / disassembling apparatus of the present invention.

FIG. 8 is an operation explanatory view showing another operation example on the cell assembly side of the cell assembling / disassembling apparatus of the present invention.

FIG. 9 is an operation explanatory view showing another operation example on the cell disassembly side of the cell assembling / disassembling apparatus of the present invention.

FIG. 10 is a detailed explanatory view showing a detailed partial configuration and another operation of the cell assembling / disassembling apparatus of the present invention.

FIG. 11 is an operation explanatory view showing another operation example on the cell assembling side of the cell assembling / disassembling apparatus of the present invention.

FIG. 12 is an operation explanatory view showing another operation example on the cell disassembly side of the cell assembling / disassembling apparatus of the present invention.

FIG. 13 is a detailed explanatory view showing a detailed partial configuration and other operations of the cell assembling / disassembling apparatus of the present invention.

FIG. 14 is a format diagram showing the structure of cells and data processed by the cell assembling / disassembling apparatus.

[Explanation of symbols]

101 ... Cell assembling / disassembling device, 103 ... Congestion notification receiving means, 104 ... Data thinning means, 105.
..Cell assembly means 106 ... ATM network,
107 ... High-speed digital line, 109 ... Cell disassembling means,
110 ... Means for complementing data, 151 ...
Cell 205: Congestion notification.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kenji Hiraiwa 216 Totsuka-cho, Totsuka-ku, Yokohama-shi, Kanagawa Hitachi Information Technology Division

Claims (18)

[Claims] 1. A cell assembling / disassembling apparatus for converting first data having a fixed bit rate into an ATM cell and transferring the first data in the cell through an ATM network. A detecting means for detecting a congestion notification from the network; a cell assembling means for assembling and transferring to the cell second data obtained by thinning out predetermined data from the first data corresponding to the output of the detecting means; A cell disassembling means for complementing the data thinned out by the assembling means after the second data disassembling, and when the ATM network is congested, the first data is thinned out to reduce the amount of cells transferred to the ATM network to reduce congestion. A cell assembling / disassembling device that is avoided 2. A cell assembling / disassembling apparatus for converting fixed bit rate data and an ATM cell and transferring the data in the cell through an ATM network, wherein the cell assembling / disassembling apparatus notifies a congestion notification from the ATM network. Detecting means for detecting and data thinning means for thinning out predetermined data from the data corresponding to the output of the detecting means, cell assembling means for assembling and transferring cells, disassembling means for receiving and disassembling cells, and the data thinning means after disassembling Data complementation means for complementing the thinned-out data, and transferring the first cell obtained by converting the data into cells by the cell assembling means as it is and decomposing the received first cell into data by the decomposing means. And a second operation mode in which the data thinned out by the data thinning means at the time of ATM network congestion is made into cells by the cell assembling means and transferred. A second operation mode is provided in which the received second cell is decomposed into data by the decomposing means and the thinned data is complemented by the data complementing means, and when the ATM network is congested, the second operation mode is changed from the first operation mode. A cell assembling / disassembling apparatus which shifts to the second operation mode and transfers the second cell to avoid congestion of an ATM network. 3. The first operation from the cell assembling side including the cell assembling means of the cell assembling / disassembling apparatus to the cell disassembling side including the cell disassembling means corresponding to the output of the detecting means. 3. The cell assembling / disassembling apparatus according to claim 2, further comprising means for notifying the mode switching between the mode and the second operation mode, wherein the cell assembling side and the cell disassembling side are synchronously operated in the same operation mode. 4. A cell assembling / disassembling apparatus which converts fixed bit rate data and ATM cells and transfers the fixed bit rate data by the cells in an ATM network. Detecting the congestion notification of the cell, selecting a predetermined time slot from the data of the fixed bit rate corresponding to the output of the detecting means and the number of bits to thin the data in the time slot to thin the data And cell disassembling means for compensating the data thinned by the assembling means after reproducing the received cells and reproducing data of a fixed bit rate after disassembling the received cells. A cell assembling / disassembling apparatus which thins out data to reduce the amount of cells transferred to the ATM network and avoid congestion. 5. A cell assembling / disassembling apparatus for converting fixed bit rate data and an ATM cell and transferring the data in the cell through an ATM network, wherein the cell assembling / disassembling apparatus notifies a congestion notification from the ATM network. Detecting means for detecting, means for selectively discarding predetermined cells corresponding to the output of the detecting means and thinning out data in cell units, and advancing the sequence number contained in the header of the cell by the number of thinned cells A means for giving a sequence number, a cell assembling means for transferring cells, and a fixed bit rate for detecting the discontinuity of the received cell sequence numbers and complementing the data of cells selectively discarded by the cell assembling means. Cell decomposing means for reproducing the data of the ATM, and when the ATM network is congested, the data of the fixed bit rate is thinned out in cell units,
A cell assembling / disassembling device that avoids network congestion. 6. A cell assembling / disassembling apparatus which converts fixed bit rate data and ATM cells and transfers the data in the cells via an ATM network, wherein the cell assembling / disassembling apparatus notifies a congestion notification from the ATM network. Detecting means for detecting, thinning means for selecting and thinning out data in predetermined cell units corresponding to the output of the detecting means, cell assembling means for assembling and transferring cells, and disassembling received cells into data Decomposing means, timing means for detecting the interval between the receiving cells, and complementing and fixing the data thinned out in cell units by the thinning means in the idle time between the receiving cells corresponding to the output of the timing means. A data complementing means for reproducing bit rate data is provided, and when the ATM network is congested, the fixed bit rate data is thinned out in cell units to avoid congestion of the ATM network. Assembly and disassembly apparatus. 7. A cell assembling / disassembling apparatus which converts fixed bit rate data and ATM cells and transfers the data in the cells through an ATM network, wherein the cell assembling / disassembling apparatus converts predetermined data from the data. It consists of a cell assembling unit for thinning out and assembling and transferring to a cell, and a cell disassembling unit for compensating the data thinned out at the cell assembling unit after disassembling the received cell. The cell assembling side thins out the ATM network. A cell assembling / disassembling apparatus configured to reduce the amount of cells to be transmitted and complement the same amount of data for transmission / reception on the cell disassembly side to maintain the same data structure of fixed bit rate between transmission and reception. 8. A cell assembling / disassembling apparatus which converts fixed bit rate data and ATM cells and transfers the data in the cells through an ATM network, wherein the cell assembling / disassembling apparatus converts predetermined data from the data. It comprises a cell assembling unit for thinning out and assembling and transferring to a cell, and a cell disassembling unit for compensating the data thinned out by the cell assembling unit after disassembling the received cell, and converting the data as it is into cells at the cell assembling unit. A first operation mode in which the first cell is transferred and the received first cell is decomposed into data by the decomposition means,
When the ATM network is congested, the cell thinning data is thinned and transferred to a second cell, and the second cell received by the disassembling means is disassembled to complement the data thinned out by the cell assembling section. A second operation mode for
A cell assembling / disassembling apparatus for avoiding ATM network congestion by shifting from the first operation mode to the second operation mode when the network is congested. 9. A cell assembling side including the cell assembling means of the cell assembling and disassembling apparatus, and a first cell disassembling side including the cell disassembling means from the cell assembling side corresponding to an output of the detecting means. 9. The cell assembling / disassembling apparatus according to claim 8, further comprising means for notifying a mode switching between the operation mode and the second operation mode, wherein the cell assembling side and the cell disassembling side are synchronously operated in the same operation mode. 10. A cell assembling / disassembling device for converting fixed bit rate data and variable bit rate data into ATM and transferring or exchanging ATM cells.
In the TM communication network, the fixed bit rate data and A
The cell assembling / disassembling device for converting to a TM cell is thinned out by the cell assembling unit after disassembling the received cell and a cell assembling unit for assembling and transferring predetermined data from the fixed bit rate data to the cell. A cell assembling / disassembling device for converting data of the fixed bit rate and ATM cells when congestion occurs in the ATM network, and a cell amount for transmitting the data of the fixed bit rate. ATM for reducing congestion and recovering congestion of the ATM network
Communication network. 11. A cell assembling apparatus for converting fixed bit rate data into an ATM cell and transferring the cell to an ATM network, wherein the cell assembling apparatus detects a congestion notification from the ATM network. A cell assembling apparatus, comprising: notifying means for notifying the apparatus for receiving and disassembling cells from the cell assembling apparatus that the cell assembling operation corresponding to the output of the detecting means will be performed. 12. A cell assembling apparatus for converting fixed bit rate data into ATM cells and transferring the cells to an ATM network, wherein the cell assembling apparatus responds to the congestion notification when detecting the congestion notification from the ATM network. A cell assembling apparatus that reduces the amount of cells to be transferred to the ATM network, and reduces the amount of cells into which the data of the fixed bit rate is converted when congestion of the ATM network is smaller than that before the congestion notification is detected. 13. A cell disassembling device for disassembling an ATM cell transferred from an ATM network and converting the ATM cell into fixed bit rate data, wherein the cell disassembling device receives an ATM network congestion notification from an ATM network or a cell assembling device. Then, the cell disassembling apparatus that complements the dummy bits to the data obtained by disassembling the received cells and outputs the fixed bit rate data including the dummy bits when the ATM network is congested. 14. An ATM communication network for converting fixed bit rate data and variable bit rate data into ATM cells and transferring or exchanging the ATM cells. When the ATM network is congested, the fixed bit rate is fixed. An ATM communication network in which a cell assembling device for converting bit rate data into ATM cells reduces the amount of cells transmitted to the ATM network to recover congestion of the ATM network. 15. A cell assembling apparatus for converting fixed bit rate data into ATM cells and transferring the cells to an ATM network, wherein the cell assembling apparatus detects the congestion notification from the ATM network, and then the fixed bit rate. A cell assembling apparatus for assembling a cell by deleting at least 1 bit or more of the data of the time slot carrying the data, and transmitting the cell to the ATM network. 16. A cell assembling apparatus for converting fixed bit rate data into an ATM cell and transferring the cell to an ATM network, wherein the cell assembling apparatus detects the congestion notification from the ATM network, and then the fixed bit rate. A cell assembling apparatus that discards at least one or more cells from a cell string composed of a plurality of cells obtained by converting the above data and transmits the cells to the ATM network. 17. A cell assembling apparatus for converting fixed bit rate data into ATM cells and transferring the cells to an ATM network, wherein the cell assembling apparatus detects the congestion notification from the ATM network, and then the fixed bit rate. A cell assembling apparatus which discards at least one or more cells from a cell string composed of a plurality of cells obtained by converting the data and transmits a cell string having discontinuous identifiers for identifying the cell order to the ATM network. 18. A cell assembling apparatus for converting fixed bit rate data into ATM cells and transferring the cells to an ATM network, wherein the cell assembling apparatus detects the congestion notification from the ATM network, and then the fixed bit rate. A cell assembling apparatus for assembling cells by discarding at least one bit number of cells from the data string and transmitting the cells to the ATM network.