JP2000269969A - Method for ensuring and controlling transmission band by atm communication and atm communication unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain band warrant control with higher accuracy that can cope with the case, even when a quantity of short packets to be sent is increased rapidly in a short time. SOLUTION: A quantity comparison means 12 compares a data quantity equivalent to a distributed band with an accumulated quantity of data actually sent, a read quality class discrimination means 8 selects a quality class by taking precedence of tight request delay quality from among the quality classes, where the quantity of data sent actually is not in excess of the quantity of data equivalent to the distributed band over others. When an ATM cell payload is not satisfied by only this, the means 8 selects a quality class to be read in the order of tighter request delay quality as to quality classes, where the data quantity equivalent to the distributed band is transmitted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a transmission band guarantee control method and an ATM communication apparatus in ATM communication.

[0002]

2. Description of the Related Art As a method suitable for transferring information at a low bit rate, there is an ATM communication method in which a variable-length short packet is multiplexed into an ATM cell payload and transmitted.

In this communication system, a plurality of quality classes are provided in a short packet, a transmission band is allocated for each quality class, and the band actually used for each quality class is
By controlling so as to approach the allocated band, ATM communication satisfying the required quality can be performed (transmission band guarantee control).

One example of a system for performing transmission band guarantee control is as follows.
It is described in Proceedings of the 998 IEICE General Conference (B-6-27, "Study of AAL Type 2 multiplexing system" Ono et al., Fujitsu Laboratories).

The gist of this method is to appropriately determine the scheduled output time of the next short packet in the quality class based on the distribution band and the size of the short packet read from the buffer immediately before.

[0006]

In the above conventional method,
The transmission time of the next short packet is determined based on the size of the short packet read from the buffer immediately before.

Therefore, when a large number of short packets of the priority class suddenly arrive in a period from the reading time of the previous short packet to the transmission time of the next short packet (that is, when a short packet arrives in a burst) ), Since such a state change cannot be followed, an increase in the multiplex wait delay of a short packet is assumed. AT
In M communication, data whose delay exceeds an allowable value is discarded in order to guarantee quality. Therefore, if a short packet that arrives in a burst belongs to a priority class in which the required delay quality is strict,
Since the permissible value is small, the degree of data discarding increases, and as a result, communication quality may decrease.

Further, since a short packet "read from the buffer" is not always transmitted (for example, an attempt is made to divide a short packet into front and rear portions, but the latter half times out and the short packet is timed out). Is eventually discarded and not sent),
In the band guarantee control based on the short packet size “read from the buffer” as in the above-described method, an error may occur between the calculated allocated band and the band actually used.

The present invention has been made in view of such a point, and an object of the present invention is to realize a more accurate band guarantee control which can cope with a case where the amount of short packets to be transmitted rapidly increases in a short time. And

[0010]

According to the transmission bandwidth guarantee control method for ATM communication of the present invention, the transmittable data size per predetermined time, which is determined based on the transmission bandwidth allocated to each quality class, Is compared with the total size of the data actually transmitted to the transmission line in a time not exceeding, and a quality class in which the total of the data size actually transmitted is smaller is detected. Then, from the detected quality classes, those with strict required delay quality are preferentially selected,
ATM the short packets of the selected quality class
Multiplex to cell payload.

Preferably, even if short packets are multiplexed by performing the priority control as described above, if there is still room in the ATM cell payload, the restriction on the actual transmission data size is removed and the required delay quality is reduced. The other quality class is selected under the condition that priority is given to the stricter one, and short packets of the quality class are multiplexed to assemble the ATM cell payload.

In the present invention, it is determined whether or not a short packet of the quality class can be transmitted based on the "actual transmission data amount", so that the accuracy of the transmission band guarantee can be improved.

When the actual transmission data amount does not reach the data amount corresponding to the allocated band, the quality class having the strict required delay quality is transmitted preferentially. Therefore, if short packets of a quality class with strict required delay quality arrive at the buffer in a burst manner (for example, the packet is hardly accumulated in the buffer until a certain time,
If the number of short packets suddenly increases from a certain time), short packets of the quality class are reliably prioritized and multiplexed, so that it is possible to cope with a sudden increase in the number of short packets. Service quality is improved for quality classes with strict required delay quality.

[0014] Further, in the state where the ATM cell payload is not satisfied, there is no short packet to be transmitted for a quality class that has not yet transmitted a short packet of the total size corresponding to the allocated band (that is, a priority quality class). If this happens (or if it does not exist from the beginning), short packets of the quality class that have already sent short packets of total size
Since transmission can be further performed in the order of the required quality, the line use efficiency can be improved.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In a first aspect of the transmission bandwidth guarantee control method for ATM communication according to the present invention, when information is transmitted by multiplexing a short packet with an ATM cell payload, a quality class of the short packet is used for each packet. A transmission band assurance control method for guaranteeing a transmission band, which is determined based on a transmission band allocated to each quality class, a transmittable data size per a predetermined time, and an actual data size within a time not exceeding the predetermined time. A quality class in which the total size of the actually transmitted data does not reach the transmittable data size is detected by comparing the total size of the transmitted data with the total size of the transmitted data. Is selected under the condition that priority is given to the short packet belonging to the selected quality class.
It is multiplexed with the M cell payload and transmitted.

Thus, it is possible to accurately determine whether or not the data amount corresponding to the allocated bandwidth has actually been transmitted, and the accuracy of the bandwidth guarantee is improved. Further, even when short packets of a class with strict required delay quality arrive in a burst manner, the quality class can be efficiently multiplexed with priority given to the quality class, so that the service quality of the quality class with strict required quality is improved.

Further, in the second aspect of the transmission bandwidth guarantee control method for ATM communication according to the present invention, when deciding which quality class to select short packets to be multiplexed in the ATM cell payload, the short packets are allocated to each quality class. The size of data that can be transmitted per predetermined time, which is determined based on the transmission band, and the total size of data that is actually transmitted within a time that does not exceed the predetermined time, and the total size of data that is actually transmitted. Detects a quality class that does not reach the data size that can be transmitted, and selects one quality class under the condition that priority is given to a shorter allowable delay time from the detected quality classes,
If the short packet belonging to the selected one quality class alone cannot satisfy the ATM cell payload, priority is further given to a packet having a short permissible delay time regardless of the total size of the data actually transmitted. Other quality classes are selected according to the condition that the short packets belonging to each of the selected quality classes are ATM-selected.
It is multiplexed with the cell payload and transmitted. .

In this embodiment, if there is a margin in the ATM cell payload, short packets of a quality class which have already transmitted short packets of the total size corresponding to the distribution band can be further multiplexed in the order of the required quality. In addition to the effects of the first aspect, it is possible to further obtain the effect of increasing the line use efficiency.

In a first aspect of the ATM communication apparatus of the present invention, a plurality of buffers provided for each of the quality classes for storing multiplex-waiting short packets and read from one of these buffers are provided. ATM cell payload assembling means for multiplexing the short packets into the ATM cell payload, and allocation band equivalent data size obtaining means for obtaining a transmittable data size in a predetermined time determined for each quality class based on the allocation of the transmission band. When,
For each quality class, a transmission total size obtaining means for obtaining a total size of data actually transmitted in a time not exceeding the predetermined time, and a transmission total size obtained by the transmission total size obtaining means is equivalent to the distribution band. From among the quality classes smaller than the distribution band equivalent data size obtained by the data size obtaining means, a quality class is selected under the condition that the one with the shorter allowable delay time is given priority, and thereby, the plurality of buffers among the plurality of buffers are selected. Quality class selecting means for specifying from which buffer a short packet is read.

As a result, it is possible to provide an ATM communication device that enables high-efficiency and high-quality short packet transmission.

According to a second aspect of the ATM communication apparatus of the present invention, a short packet assembling means for assembling a short packet from information to be transmitted, and a short packet output from the short packet assembling means for each short packet quality class Buffer means for buffering the short packets buffered in the buffer means, ATM cell payload assembling means for reading the short packets from the buffer means and assembling an ATM cell payload, A which adds an ATM cell header to the ATM cell payload output from the ATM cell payload assembling means to assemble the ATM cell and outputs the ATM cell
TM cell assembling means, ATM cell sending timing managing means for giving a cell sending request as a cell payload assembling start timing to the ATM cell payload assembling means, and data which can be transmitted at a predetermined time based on a sending band allocated to each quality class. Means for calculating and holding the distribution band equivalent data amount for calculating and holding the amount, and sending and calculating the accumulated data amount of the short packets output to the transmission line for each quality class during a time not exceeding the predetermined time. Means for calculating and holding the total size,
Cycle timer means for clearing the value held by the holding means at a predetermined cycle, and magnitude comparing means for comparing the magnitudes of the output from the distribution bandwidth equivalent data amount calculating / holding means and the transmission total size calculating / holding means, Reading a short packet from a buffer unit of any quality class based on each output of an allowable delay time holding unit for holding an allowable delay time for each quality class, the magnitude comparison unit, the allowable delay time holding unit, and the buffer management unit. Reading quality class determining means for determining whether

As a result, it is possible to provide an ATM communication apparatus which enables high-efficiency and high-quality short packet packet transmission.

Further, by constructing a communication system, an ATM switch, or a wireless base station device using the ATM communication device of the present invention, it is possible to realize unprecedented high-quality information transmission.

Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of the ATM communication system of the present invention.

The ATM cell transmitting device 13 has a “transmission band guarantee control function” according to the quality class of the short packet multiplexed in the ATM cell payload, and is transmitted to the ATM cell receiving device 14 via the physical line L1. Send an ATM cell.

[0027] Here, "transmission band guarantee" means that when a certain long time is taken and the average is viewed, the actual used band of each quality class approaches the band allocated to each quality class. It is to control.

For example, if the maximum transmission amount of a physical line is 1 Mb
ps] and 600 k [bp] for quality class 1.
s], 400 k [bps] is assigned (allocated) for quality class 2 in the long run (on average)
When viewed, the control is performed so that the actual bandwidth used does not fall below the data amount corresponding to the allocated bandwidth.

As a technique for realizing such a bandwidth guarantee, in the present embodiment, when a short packet is read from a multiplex wait buffer provided for each quality class, a "predetermined time (unit time)" is used. And the data size corresponding to the allocated bandwidth in the above "predetermined time (unit time)"
Within the time that does not exceed the actual transmission data size, and detects a quality class whose actual transmission data size is smaller.If there are multiple detected quality classes, the allowable delay time is shorter. (That is, a method of selecting a quality class of a short packet to be multiplexed each time based on an actual transmission data size).

Here, the "data size corresponding to the allocated band within the predetermined time (unit time)" means that the data can be transmitted in the predetermined time (unit time) calculated based on the transmission band allocated to the quality class. When the distribution of the transmission band is determined, the data size is uniquely determined.

On the other hand, “the size of data actually transmitted within a time not exceeding a predetermined time (unit time)” is
For example, the first time which is the starting point of the above-mentioned predetermined time (unit time)
The measurement of the accumulated value of the transmission data size is started from the timing of the second time, and the second time after the lapse of the time t that does not exceed the predetermined time (satisfies the relationship of 0 ≦ t ≦ T when the predetermined time is T) from that time. At the time point (measured value (cumulative value of transmission data)). More specifically, according to the present embodiment, “the period from the time when the measured value is periodically reset (cleared) by the periodic timer to the time when the reading of the short packet is to be performed is started. (Period) t, the total size of the data actually transmitted.

In the ATM cell transmitting apparatus 13 shown in FIG.
FIG. 3 shows a basic operation for guaranteeing the transmission band of the short packet.

That is, as the first stage, the actual output to the transmission path from the time of zero clear to the time of trying to read out the short packet is smaller than the amount of data that can be transmitted in the distribution band for the predetermined time T (T> 0). Quality classes are selected in ascending order of the allowable delay time from the quality classes in which the data amount of the short packets is small (step 40).
Then, if the short packet that satisfies the ATM cell payload cannot be read by the first step alone, the second step is to determine the allowable delay irrespective of the accumulated data of the short packet output to the transmission line. Quality classes are selected in ascending order of time (step 41).

That is, for a quality class in which data corresponding to the allocated band has already been transmitted per predetermined time, the data size that can be transmitted in the allocated band has already been transmitted, so that the data size equivalent to the allocated band is still transmitted. The quality class that does not transmit the data amount is transmitted with priority.

The first feature in this case is that it is determined whether or not data corresponding to the allocated band has been transmitted, based on the "cumulative amount of data actually output to the transmission path".
The second feature is that a "rule of giving the highest priority to the one with strict required delay quality as a criterion for selecting a quality class" is applied.

[0036] Thus, accurate bandwidth guarantee with little error can be performed, and when short packets of a quality class with a short required delay quality reach the buffer in bursts, data equivalent to the allocated bandwidth has already been transmitted. Except in the case where there is, first, transmission of such a strict quality class is given priority and is efficiently transmitted to the transmission path, so that deterioration of transmission quality is prevented.

Even if such control is performed, the AT
In the case where the M cell payload cannot be satisfied, the quality class that has already transmitted data equivalent to the allocated bandwidth is also subject to the condition that priority is given to those with strict required delay quality.
By making the transmission target, the utilization efficiency of the physical line can be improved.

Hereinafter, a specific configuration and operation of the ATM cell transmitting device 13 will be described.

As shown in FIG. 1, the ATM cell transmitting apparatus 13 includes a short packet assembling means 1 for assembling a short packet from information to be transmitted, and a short packet output from the short packet assembling means 1 as a short packet quality. Buffer means 2-1 to 2-m (m> 1) for buffering each class, and a buffer for managing the size and waiting time of short packets buffered in these buffer means 2-1 to 2-m Management means 6, ATM cell payload assembling means 3 for reading short packets from buffer means 2-1 to 2-m and assembling an ATM cell payload; Assemble the ATM cell by adding
ATM cell assembling means 4 for outputting M cells, ATM cell transmission timing managing means 5 for giving the ATM cell payload assembling means 3 a cell transmission request which is a cell payload assembling start timing, and time T ( (T> 0) calculating and holding a distribution band equivalent data amount calculating / holding unit 9 for calculating / holding the amount of data that can be transmitted, and calculating / holding the accumulated data amount up to time T of the short packet output to the transmission line for each quality class. Sending total size calculating / holding means 10, a period timer means 11 for clearing the value held by the sending total size calculating / holding means 10 with a cycle T, and an output and sending sum of the distribution band equivalent data amount calculating / holding means 9. A magnitude comparing means 12 for comparing the output from the size calculating / holding means 10 to determine the magnitude thereof; Allowable delay time holding means 7 for holding the delay time, magnitude comparing means 12, allowable delay time holding means 7
And read quality class determining means 8 for determining from which output of the buffer means the buffer packet of which quality class is to be read. Reference numeral 15 is a distribution gate for distributing short packets to each of the buffers 2-1 to 2-m, and reference numeral 16 is a read gate for selectively reading short packets of a specific quality class. is there.

The basic (general) operation of such an ATM cell transmitting apparatus 13 will be described.

The information to be transmitted is assembled into short packets by the short packet assembling means 1 and buffered in the buffer means 2-1 to 2-m according to the quality class. The waiting time of the short packet in the buffer means 2-1 to 2-m is managed by the buffer managing means 6 based on the information from the permissible delay time holding means 7, and the short packet whose waiting time exceeds the permissible delay is discarded. You.

ATM cell payload assembling means 3 receiving a cell transmission request from ATM cell transmission timing management means 5
Sends a short packet read request to the read quality class determination means 8 if there is an empty area in the cell payload being assembled. The read request is repeatedly output until all the ATM cell payloads are satisfied. There are two cases in which the ATM cell payload is satisfied. One is when the total size of the multiplexed short packets is exactly the size of the ATM cell payload, and the other is when the total exceeds the size of the ATM cell payload. If the size of the ATM cell payload is exceeded, the short packet read last is divided, and the latter half of the divided packet is multiplexed with the cell payload assembled at the time of the next cell transmission request. Since the divided second half is output at the time of the next cell transmission request, a waiting time occurs in the ATM cell payload assembling means 4, and the waiting time combined with the waiting time in the buffer means exceeds the allowable delay time. If discarded.

Upon receipt of the read request, the read quality class determining means 8 selects one of the buffer means 2-1 to 2-m, and a short packet is output from the selected buffer means to the ATM cell payload assembling means 3. You. When the short packet no longer exists in any of the buffer units 2-1 to 2-m, the short packet is notified from the buffer management unit 6 to the quality class determination unit 8, and the quality class determination unit 8 outputs the ATM cell payload assembling unit 3 To the end of reading. As a result, the ATM cell payload assembling means 3 pads the empty area of the ATM cell payload and outputs the ATM cell payload.

The general operation of the ATM cell transmitting device 13 has been described above. Next, an operation of determining a read quality class, which is a characteristic operation of the present embodiment, will be specifically described with reference to FIG.

First, the distribution band equivalent data amount calculating / holding means 9 calculates the distribution band equivalent data amount for each quality class (step 20). The distribution band-equivalent data amount i of the quality class i is represented by Ri (0 ≦ Ri ≦ 1), which is the ratio of the distribution band of the quality class i, and V = the band available for transmission of short packets in the VC (virtual channel).
[Bps], the distribution band equivalent data amount i = T × V
× Ri [bit].

Further, the sending total size calculating / holding means 10
, The transmission total size is cleared to "0" for each quality class (step 21).

Next, a clear request from the cycle timer means 11 is determined (step 22). If there is a request, the total transmission size for each quality class is cleared to "0" (step 23). If there is no request, it is determined whether there is a read request from the ATM cell payload assembling means 3 (step 24).

If there is no read request, the flow returns to step 22. If there is a read request, the ATM cell payload assembling means 3 detects the size of the latter half of the short packet divided at the time of the previous cell transmission request. The total sending size calculating / holding means 10 adds the total sending size of the corresponding quality class (step 25). Subsequently, a quality class selection routine to be read (steps 26 to 35) is executed. In this routine, the quality class to be read out is specified by using the variable "n" in consideration of the plurality of quality classes while performing the classification.

First, 1 is assigned to a variable n (step 2
6) It is determined whether there is a short packet in the buffer means of the quality class having the nth shortest allowable delay time (step 27). If there is, it is determined whether or not the total read size is smaller than the data amount corresponding to the allocated band in the quality class (step 31). If the quality class is smaller, the quality class has not yet been transmitted corresponding to the allocated bandwidth, so it is determined that the quality class can be read, and one short packet is read from the buffer means of the quality class (step 32). 3 receives the short packet transmission size corresponding to the short packet, and adds the value to the total transmission size of the quality class (step 33). Here, the short packet transmission size is equal to the short packet size if the short packet is not divided, and is a value obtained by subtracting the size of the latter half part from the short packet size if the short packet is divided.

Next, it is determined whether or not there is a read request from the ATM cell payload assembling means 3 (step 34). If there is a request, the flow returns to step 27;
Return to step 22.

If the total read size is not smaller than the data amount corresponding to the allocated bandwidth in step 31 described above, the data corresponding to the allocated bandwidth has already been transmitted for the quality class. For the quality class having a long allowable delay time, it is determined whether there is a short packet in the buffer means and whether the total read size is smaller than the amount of data corresponding to the allocated band (step 35). 4
2; if yes, proceed to step 28, where variable n
Is incremented (increased by 1).

Also, if the determination in step 27 is No, the value of the variable n is increased by 1 (step 28). Then, it is determined whether the value of n is larger than the total number of quality classes (step 29). If it is not larger, the process returns to step 27, and if it is larger, a read end notification is sent to the ATM cell payload assembling means 3 ( Step 30) and return to step 22.

As described above, according to the embodiment of the present invention, a quality class selection method for assembling a cell payload by reading a short packet from a multiplex waiting buffer existing for each quality class in response to a cell transmission request is as follows.
In the first stage, among the quality classes in which the accumulated data amount of the short packets actually output to the transmission path is smaller than the data amount that can be transmitted in a predetermined time based on the distribution band, the quality classes are arranged in ascending delay time order. If the short packet that satisfies the cell payload cannot be read out only in the first stage, in the second stage, regardless of the accumulated data amount of the short packet output to the transmission path,
By selecting quality classes in the order of the shortest allowable delay time, short packets of a quality class with strict delay quality are preferentially transmitted to suppress quality deterioration, and the calculated allocation bandwidth by discarding the latter half of the short packet division Band assurance control that eliminates an error between the band and the band actually allocated. In addition, if there are no short packets in the quality class that does not transmit the short packets for the allocated bandwidth, short packets of the quality class that have already transmitted the short packets for the distributed bandwidth can be further transmitted, so that the line use efficiency is reduced. Can be enhanced.

[0054]

As described above, according to the present invention,
It is possible to realize more accurate bandwidth guarantee control that can cope with a case where the amount of short packets to be transmitted increases rapidly in a short time. In particular, transmission quality degradation can be suppressed by preferentially sending short packets of a quality class with a strict delay quality, and furthermore, the actual allocation and calculated allocation bandwidth due to discarding the latter half of the short packet division Bandwidth guarantee control that eliminates errors from the band can be realized. Also, if there are no short packets in the quality class that has not transmitted the short packets corresponding to the distribution band, the short packets of the quality class that have already transmitted the short packets corresponding to the distribution band can be further transmitted. Usage efficiency can also be increased.

[Brief description of the drawings]

FIG. 1 is a block diagram of an ATM communication system according to an embodiment of the present invention.

FIG. 2 is a flowchart showing a specific operation procedure in the embodiment of the present invention.

FIG. 3 is a flowchart showing a characteristic operation in the embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Short packet assembling means 2-1 to 2-m buffer means 3 ATM cell payload assembling means 4 ATM cell assembling means 5 ATM cell transmission timing managing means 6 Buffer managing means 7 Allowable delay time holding means 8 Read quality class determining means 9 Allocation Band-equivalent data amount calculating / holding means 10 Total sending size calculating / holding means 11 Period timer means 12 Size comparing means 13 ATM cell transmitting device 14 ATM cell receiving device

Claims (7)

[Claims] 1. A transmission band guarantee control method for guaranteeing a transmission band for each quality class of a short packet when information is transmitted by multiplexing a short packet on an ATM cell payload. Determined based on the transmission band
By comparing the transmittable data size per predetermined time and the total size of the data actually transmitted within a time not exceeding the predetermined time, the total size of the data actually transmitted becomes the transmittable data size. A quality class that has not been reached is detected, a quality class is selected under a condition that priority is given to a quality class having a shorter allowable delay time from the detected quality classes, and short packets belonging to the selected quality class are transferred to the ATM cell payload. A transmission bandwidth guarantee control method for ATM communication, characterized in that the transmission band is multiplexed and transmitted. 2. A transmission band assurance control method for guaranteeing a transmission band for each quality class of the short packet when transmitting information by multiplexing a short packet in the ATM cell payload, comprising: When deciding which quality class to select short packets to be determined, it is determined based on the transmission bandwidth allocated to each quality class.
By comparing the transmittable data size per predetermined time and the total size of the data actually transmitted within a time not exceeding the predetermined time, the total size of the data actually transmitted becomes the transmittable data size. A quality class which has not been reached is detected, and one quality class is selected under the condition that priority is given to a quality class having a shorter allowable delay time from the detected quality classes, and a short circuit belonging to the selected one quality class is selected. If the packet alone cannot satisfy the ATM cell payload, another quality class is further selected according to the condition that priority is given to one having a shorter allowable delay time, irrespective of the total size of the data actually transmitted. ATM short packets belonging to each selected quality class
A characterized by being multiplexed and transmitted to a cell payload
Transmission bandwidth guarantee control method for TM communication. 3. An ATM communication apparatus for performing transmission band control for each quality class of a short packet when multiplexing and transmitting a short packet to an ATM cell payload, wherein the short packet waiting for multiplexing is stored. A plurality of buffers provided for each quality class; ATM cell payload assembling means for multiplexing short packets read from one of these buffers into the ATM cell payload; A distribution band-equivalent data size obtaining means for obtaining a transmittable data size in a predetermined time, which is determined based on the data; and a transmission total for obtaining, for each quality class, a total size of data actually transmitted in a time not exceeding the predetermined time. Size obtaining means, and the transmission determined by the transmission total size obtaining means Quality class selection for selecting the quality class under the condition that the total size is smaller than the distribution band equivalent data size obtained by the distribution band equivalent data size obtaining means and the one with the shorter allowable delay time is prioritized. ATM communication device comprising: 4. An ATM communication apparatus for performing transmission band control for each quality class of a short packet when multiplexing and transmitting a short packet to an ATM cell payload, wherein the short packet assembles the short packet from information to be transmitted. Assembling means, buffer means for buffering the short packets output from the short packet assembling means for each quality class of the short packets, and buffer managing means for managing the size of the short packets buffered in the buffer means. ATM cell payload assembling means for reading out short packets from the buffer means to assemble an ATM cell payload, and adding an ATM cell header to the ATM cell payload outputted from the ATM cell payload assembling means to form an ATM cell. ATM cell assembling means for outputting vertical ATM cells, ATM cell sending timing managing means for giving the ATM cell payload assembling means a cell sending request which is a cell payload assembling start timing, and ATM cell assembling means based on the sending bandwidth allocated to each quality class. Calculates and holds the amount of data that can be transmitted in a predetermined time
Holding means, total sending size calculating and holding means for calculating and holding the accumulated data amount of the short packets output to the transmission path for each quality class in a time not exceeding the predetermined time, and Cycle timer means for clearing the value held by the holding means at a predetermined cycle, and magnitude comparing means for comparing the magnitudes of the output from the distribution bandwidth equivalent data amount calculating / holding means and the transmission total size calculating / holding means, Reading a short packet from a buffer unit of any quality class based on each output of an allowable delay time holding unit for holding an allowable delay time for each quality class, the magnitude comparison unit, the allowable delay time holding unit, and the buffer management unit. An ATM communication device, comprising: a read quality class determining unit that determines whether the data is read or not. 5. The ATM communication device according to claim 3, which functions as an ATM cell transmitting device, and an ATM receiving device that receives an ATM cell transmitted via a transmission line. ATM communication system. 6. An ATM exchange comprising the ATM communication device according to claim 3. 7. A radio base station apparatus comprising the ATM communication apparatus according to claim 3.