KR100334318B1 - Apparatus and method for AAL2 ATM transferring - Google Patents

Abstract

The present invention relates to an AAL2 ATM transmission apparatus and method for improving the quality of service by guaranteeing a transmission band in accordance with delay requirements for heterogeneous traffic groups.

The present invention performs AAL2 multiplexing for each traffic group for various input traffic groups having different delay characteristics, and performs cell generation by introducing a cell generation timer to suppress cell generation delay of the delay sensitive traffic group. Generated cells are multiplexed and transmitted by weighted round robin based on the load of each input traffic group and the delay requirements for each traffic group in one cell multiplexer, so that delays generated with various delay requirements according to activation of multimedia services It is possible to improve link transmission efficiency of the sensitive traffic group and the delay insensitive traffic group.

Description

Apparatus and method for AAL2 ATM transferring}

The present invention relates to an AAL2 ATM transmission apparatus and method, and more particularly, to an AAL2 ATM transmission apparatus and method for guaranteeing a transmission band according to delay requirements for heterogeneous traffic groups, thereby improving quality of service.

In general, Asynchronous Transfer Mode (hereinafter referred to as ATM) is a transmission / switching technology that is the core of the broadband integrated information network (B-ISDN), and all information is a fixed length block called an ATM cell. By dividing and transmitting them sequentially, the ATM network transmits multiplexed traffic by accommodating various traffic sources. Representative traffic includes voice, data, image, and the like.

In the past, an AAL2 multiplexing scheme was proposed to accommodate a single traffic, and an AAL2 multiplexed transmission scheme and an AAL2 / AAL5 multiplexed transmission scheme for voice and data have also been proposed. In addition, a method of introducing a cell generation timer for a real-time traffic group has also been proposed.

However, all of the above proposed schemes remain at the conceptual level, and the proposal for the overall detailed transmission apparatus configuration has not been surfaced, and no consideration has been given to the transmission scheme that can accommodate traffic groups having various delay characteristics. It is true.

On the other hand, with the activation of multimedia services, a situation arises in which a heterogeneous traffic group must be supported in an arbitrary subscriber network transmission link, and these heterogeneous traffic groups have different delay requirements.

In other words, delay-sensitive traffic groups that require real-time transmission of voice, compressed coded video, multimedia sessions of voice and video, and real-time data services will not only have different delay characteristics for each type of traffic group but also file transmission and web. Maximum delay thresholds exist even in delay-insensitive traffic groups where real-time transmission of a service is not essential.

Therefore, the AAL2 ATM transmitter needs to be able to meet all the delay requirements of the individual traffic groups.

Therefore, for the delay sensitive traffic group, it is necessary to satisfy the delay requirement by reducing the delay factor in the AAL2 ATM transmission apparatus as compared to the delay insensitive traffic group.

As described above, delay factors include delays in generating AAL2 ATM cells and delays in cell multiplexing for link transmission. Cell generation delays occur in cell payload multiplexing, which is characteristic of AAL2. ATM cell payload excluding the offset field A 47-octet ATM cell payload is generated when the input traffic group is not heavily loaded according to AAL2 ATM cell generation. There will be time to fill.

In addition, cell multiplexing delay is generated according to the size of the bandwidth of the corresponding traffic group in the transmission link band, and the appropriate link transmission band is operated for each traffic group in consideration of the requirement for the large and small load and the delay of the input traffic group. Is required.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described necessity, and includes a cell generation timer for performing AAL2 multiplexing for each traffic group for different input traffic groups having different delay characteristics and suppressing cell generation delay of the delay sensitive traffic group. In this example, cell generation is performed, and the generated cells are multiplexed in a weighted round robin method based on the load of each input traffic group and the delay requirement for each traffic group in one cell multiplexer, thereby delaying the delay value of the delay element. It is an object of the present invention to provide an AAL2 ATM transmission apparatus and method that can be adjusted to improve the overall quality of service.

1 is a diagram showing the configuration of an AAL2 ATM transmission apparatus according to the present invention.

FIG. 2 is a diagram illustrating an AAL2 ATM cell multiplexer in FIG. 1; FIG.

3 is a flowchart for explaining an AAL2 ATM transmission method according to the present invention.

4 is a flowchart for explaining the AAL2 ATM cell multiplexing process of FIG. 3 in detail.

5 is a flowchart for explaining a transmission cell determination process of FIG. 4 in detail.

6 is a diagram showing the configuration of an AAL2 ATM transmission apparatus according to another embodiment of the present invention.

*** Explanation of symbols for the main parts of the drawing ***

10. AAL2 multiplexer, 11-1,... , 11-N. Delay sensitive AAL2 multiplexer,

13-1,... , 13-M. Delay insensitive AAL2 multiplexer,

20. AAL2 ATM cell generation unit, 21-1,... , 21-N. Delay sensitive AAL2 ATM cell generator,

23-1,... , 23-M. Delay insensitive AAL2 ATM cell generator,

30. AAL2 ATM cell multiplexer, 31. AAL2 ATM cell multiplexer buffer,

33. buffer status monitoring unit, 35. cell multiplexing weight determination unit,

37.AAL2 ATM Cell Multiplexer

AAL2 ATM transmission apparatus of the present invention for achieving the above object, a plurality of multiplexing and Common Part Convergence Sublayer (CPCS) packet conversion for each of the different delay-sensitive and delay-sensitive traffic group inputs An AAL2 multiplexer; Delay-sensitive CPCS packets received from the corresponding AAL2 multiplexers are suppressed from the cell generation delay using a cell generation timer, and are contained in the cell payload to generate delay-sensitive AAL2 ATM cells, and delay-insensitive CPCS packets are generated from the cell payload. A plurality of AAL2 ATM cell generation units for generating delay insensitive AAL2 ATM cells; A AAL2 ATM cell multiplexer is configured to multiplex the delay sensitive AAL2 ATM cell and the delay insensitive AAL2 ATM cell received from the AAL2 ATM cell generator according to a weight-based round robin scheme.

Here, the AAL2 ATM cell multiplexing unit, one for each type of delay sensitive traffic group and delay insensitive traffic group, temporarily stores the AAL2 ATM cell received from the AAL2 ATM cell generation unit, and immediately before each cell transmission time. A buffer unit for monitoring the presence or absence of standby cells in each of the delay sensitive traffic groups and the delay insensitive traffic groups, and monitoring the number of standby cells in each of the delay insensitive traffic groups; A buffer state monitoring unit managing standby cell presence status information of each delay sensitive traffic group and delay insensitive traffic group and load state information of the delay insensitive traffic group based on the status information of each buffer received from the buffer unit; For each delay sensitive traffic group and the delay insensitive traffic group based on the standby cell presence status information of each delay sensitive traffic group and the delay insensitive traffic group and load state information of the delay insensitive traffic group received from the buffer status monitoring unit. A cell multiplexing weight determination unit determining a weight value; And a cell multiplexing unit configured to determine and multiplex the transmission cell in a weight-based round robin manner based on the weight value of each traffic group received from the cell multiplexing weight determining unit and information on standby cell presence of each traffic group.

On the other hand, AAL2 ATM transmission method according to the present invention, AAL2 multiplexing process for performing multiplexing and Common Part Convergence Sublayer (CPCS) packet conversion for each of the different delay sensitive traffic group and delay insensitive traffic group input; The delay-sensitive CPCS packets transformed in the AAL2 multiplexing process are suppressed by using a cell generation timer to suppress a cell generation delay, and a delay-sensitive AAL2 ATM cell is generated by putting them in a cell payload, and delay-insensitive CPCS packets are stored in a cell payload. Generating an AAL2 ATM cell for generating an AAL2 ATM cell; AAL2 ATM cell multiplexing is performed to multiplex the delay sensitive AAL2 ATM cell and the delay insensitive AAL2 ATM cell according to a weight-based round robin scheme.

Here, the AAL2 ATM cell multiplexing process monitors the presence or absence of a standby cell of each delay sensitive traffic group and a delay insensitive traffic group immediately before each cell transmission time point, and monitors the number of standby cells of each delay insensitive traffic group. A monitoring step of acquiring standby cell presence information of the traffic group and load state information of the delay insensitive traffic group; A weight determination process of determining a weight value of each traffic group based on standby cell presence information of each traffic group and load state information of the delay-insensitive traffic group; And a transmission cell determination process of determining and multiplexing a transmission cell in a weight-based round robin based on the determined weight value and standby cell presence information of each traffic group.

In the transmitting cell determination process, a traffic group including a standby cell exists by searching for a traffic group in a round robin order from the next traffic group of the traffic group indicated by the start pointer based on the standby cell presence information of each traffic group. Determining whether it is determined; When the traffic group in which the standby cell exists exists as a result of the determination, assigning an order index to the traffic groups in which the searched standby cell exists in an order close to the start pointer; Obtaining a random number from a random number table stored in the random number storage ROM, and separating the obtained random number by k bits by the number of traffic groups in which a standby cell exists, and normalizing the random number to a value between '0' and '1'; Comparing the normalized value one-to-one with a weight value of a traffic group in which a standby cell exists, setting a traffic group having a random number smaller than the weight value as a transmission traffic group candidate, and determining whether a transmission traffic group candidate exists; ; If the transmission traffic group candidate does not exist as a result of the determination, the cell of the traffic group having the lowest order index is determined as the transmitting cell. If the transmission traffic group candidate exists, the transport traffic group having the lowest order index among the transmission traffic group candidates Determining a cell of the candidate as a transmitting cell; And positioning the start pointer in the traffic group in which the determined transmission cell is stored.

Hereinafter, an AAL2 ATM transmission apparatus and method according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 is a road showing the configuration of the AAL2 ATM transmission apparatus according to the present invention, the AAL2 ATM transmission apparatus according to the present invention AAL2 multiplexer 10, AAL2 ATM cell generation unit 20, AAL2 ATM cell multiplexer ( 30).

In such a configuration, the AAL2 multiplexer 10 multiplexes the delay sensitive AAL2 multiplexer 11 to perform multiplexing and Common Part Convergence Sublayer (CPCS) packet conversion on each of the different delay sensitive traffic group inputs separately. 1, ..., 11-N) and a plurality of delayed insensitive AAL2 multiplexers 13-1, ..., 13-M that perform multiplexing and CPCS packet conversion separately for each of the different delayed insensitive traffic group inputs. It is made. Here, a CPCS packet has a data length of up to 44 (or 64) octets and a CPCS header of three octets.

The AAL2 ATM cell generation unit 20 suppresses the cell generation delay by using the cell generation timer to delay sensitive CPCS packets received from the corresponding delay sensitive AAL2 multiplexers 11-1, ..., 11-N. A plurality of delay sensitive AAL2 ATM cell generators 21-1, ..., 21-N for generating an AAL2 ATM cell in the payload and corresponding delay insensitive AAL2 multiplexers 13-1, ..., 13-M And a plurality of delayed insensitive AAL2 ATM cell generators 23-1, ..., 23-M for generating an AAL2 ATM cell by containing the delayed insensitive CPCS packets received from the cell payload.

As described above, the AAL2 ATM cell generator 20 generates a cell by including the CPCS packets received from the AAL2 multiplexer 10 in the cell payload, and AAL2 that several packets may be filled in one cell payload. There is a statistical multiplexing characteristic of. The statistical multiplexing characteristic of AAL2 has the advantage of increasing the transmission link efficiency, but when the load of the input traffic group is low, there is a delay in waiting for the packets previously arriving in the payload until the cell payload is filled. . In addition, when the size of the arrival packet is larger than the remaining cell payload portion, packet division is performed. In the case of accommodating several types of traffic groups in a single transmission link, such a packet is loaded under a high load situation. Link delay occurs due to the effects of packet recombination delay at the receiving end and waiting delay during recombination due to packet fragmentation.

Therefore, in order to suppress the cell generation delay as described above, a cell generation timer function having an appropriate length in accordance with the delay requirement is introduced into the delay sensitive AAL2 ATM cell generators 21-1, ..., 21-N. When the payload is formed, even if there is an empty payload portion, the padding is terminated to form a cell when the cell generation timer expires. Here, the length value of the cell generation timer is set to an appropriate value through the prediction of the maximum value of the delay requirement of the corresponding traffic group and the input packet arrival rate to prevent packet fragmentation.

The AAL2 ATM cell multiplexer 30 is a delay sensitive AAL2 ATM cell and delay insensitive AAL2 received from each corresponding AAL2 ATM cell generator 21-1, ..., 21-N, 23-1, ..., 23-M. A weighted round robin method for delayed sensitive AAL2 ATM cells and delayed insensitive AAL2 ATM cells received through a plurality of AAL2 ATM cell multiplexer buffers 31 to temporarily store ATM cells, and each of the AAL2 ATM cell multiplexer buffers 31. AAL2 ATM cell multiplexer 37 for multiplexing according to the present invention. Here, the reason for performing the multiplexing according to the weighted round robin method in the AAL2 ATM cell multiplexer 37 is to use a limited link transmission band by efficiently sharing and sharing the limited link transmission bands according to the delay requirements and the input traffic incidence. To do that.

2 is a road showing the AAL2 ATM cell multiplexer 30 in FIG. 1, the AAL2 ATM cell multiplexer 30 includes an AAL2 ATM cell multiplexer buffer 31, an AAL2 ATM cell multiplexer 37, and a buffer state. The monitoring unit 33 and the cell multiplexing weight determination unit 35 are provided.

In such a configuration, in the AAL2 ATM cell multiplexer buffer 31, which exists for each type of delay sensitive and desensitized traffic group, each AAL2 ATM cell multiplexer buffer 31 immediately before a fixed cell transmission time point. It monitors the number of standby cells of the AAL2 ATM cell multiplexer buffer 31 for each traffic group, and monitors the presence of standby cells, and AAL2 for the AAL2 ATM cell multiplexer buffer 31 for each delay insensitive traffic group. Reference value indicating that the number of standby cells in the ATM cell multiplexer buffer 31 is high a reference value for monitoring whether (i = 1, 2, ..., M) is exceeded and indicating that the number of standby cells is small It is monitored to decrease below (i = 1, 2, ..., M).

The variable i described above indicates the type of delay insensitive traffic group and the reference value. Becomes a boundary for allocating more bands to the delay insensitive traffic group when the number of standby cells in the AAL2 ATM cell multiplexer buffer 31 increases. The delay is sufficiently resolved due to the reduced load or increased bandwidth allocation of the corresponding input traffic group, and becomes a boundary for recovering a previously allocated transmission band when the number of standby cells in the AAL2 ATM cell multiplexer buffer 31 decreases. . Here, the reason for setting two reference values and the difference between the two values is to prevent the continuous repetitive transition of the number of standby cells.

Therefore, the number of standby cells is the reference value In the case where the delay-insensitive AAL2 ATM cell multiplexer buffer 31 increases, the overall state is set to a high load state, and the number of standby cells is a reference value. The threshold number of standby cells in the traffic group that increased more than Decreases below, original reference value When the traffic groups having the following number of standby cells remain in the state, the whole state is set to the low load state.

The buffer status monitoring unit 33 is based on the status information of each monitored traffic group AAL2 ATM cell multiplexer buffer 31 received from the AAL2 ATM cell multiplexer buffer 31 to determine each AAL2 ATM cell multiplexer. If there is a standby cell for the buffer 31, the standby cell presence state flag is set to '1' state, and if the standby cell is not present, the standby cell existence state flag is set to '0' state. The standby cell presence state information is transmitted to the cell multiplexing weight determination unit 35 only when another state occurs. In the case of the delay insensitive traffic group, the load state flag of the delay insensitive traffic group is set to 'H' when the state of the number of standby cells in the at least one delay insensitive AAL2 ATM cell multiplexer buffer 31 is high. When the state of the number of standby cells of the delay insensitive AAL2 ATM cell multiplexing buffer 31 is a low load state, the load state flag of the delay insensitive traffic group is set to 'L', and only delayed when a state different from the previous state occurs. The load state information of the desensitized traffic group is transmitted to the cell multiplexing weight determination unit 35.

The cell multiplexing weight determination unit 35 generates a change in the standby cell presence state in the AAL2 ATM cell multiplexing buffer 31 for any delay sensitive traffic group, or the AAL2 ATM cell multiplexing buffer (for any delay insensitive traffic group). In the case where the load state change of 31) occurs, the buffer state monitoring unit 33 receives the information on the presence or absence of a standby cell for each traffic group and the load state information of the entire delay insensitive traffic group.

As described above, the cell multiplexing weight determination unit 35 receives the information on whether there is a standby cell for each traffic group and the load state information of the entire delay-insensitive traffic group from the buffer state monitoring unit 33. Delay desensitization using a delay desensitized traffic group weight table indicating a weight for each delay desensitized traffic group provided in the weight determination unit 35 and a delay sensitive traffic group weight table indicating a weight for each delay sensitive traffic group. The weight value for each delay sensitive traffic group and delay insensitive traffic group is determined according to the presence or absence of a high load state among the load states of the entire traffic group.

Table 1 is a table showing the weight table of delay insensitive traffic group. If the status of the total delayed desensitized traffic group for each non-homogeneous traffic is high, If (i = 1, 2, ..., M), and the state of the overall delay-insensitive traffic group is a low load state, the weight value is (i = 1, 2, ..., M). Therefore, when the state of the entire delay insensitive traffic group is a high load state, the weight value for each delay insensitive traffic group is determined. (i = 1, 2, ..., M), and if the state of the entire delay insensitive traffic group is a low load state, the weight value for each delay insensitive traffic group is set. (i = 1, 2, ..., M). Where the weight value Is Is greater.

Table 2 shows the delay sensitive traffic group weight table. Weighted value when the load of the total delay-insensitive traffic group is high under each load. If (j = 1, 2, ..., N), and the state of the overall delay-insensitive traffic group is a low load state, the weight value is (j = 1, 2, ..., N). Therefore, if the load condition of the entire delay insensitive traffic group is a high load state, the weight value for each delay sensitive traffic group is determined. If the state load of the entire delay-insensitive traffic group is under low load, set the weighting value for each delay-sensitive traffic group. Set to. Here, the variable j represents the type of delay sensitive traffic group, the weight value Is Is greater.

As described above, the weight values for each traffic group determined by the cell multiplexing weight determination unit 35 are transferred to the AAL2 ATM cell multiplexer 37.

In addition, the standby cell presence status information for each traffic group is transmitted to the AAL2 ATM cell multiplexer 37 with the changed weight value when there is a change in the load state information of the delay insensitive traffic group, and the load state of the delay insensitive traffic group. If there is no information change, only standby cell presence status information for the delay sensitive traffic group is transmitted to the AAL2 ATM cell multiplexer 37.

The AAL2 ATM cell multiplexer 37 performs a weighted round robin multiplexing process with transmission intervals of a predetermined interval according to a given transmission speed of a transmission link. The determination of a transmission cell is performed from the cell multiplexing weight determination unit 35. Based on the weight values for each traffic group and the standby cell presence status of the AAL2 ATM cell multiplexing buffer 31 for each traffic group, the transmission band is assigned to each traffic group.

FIG. 3 is a flowchart illustrating an AAL2 ATM transmission method according to the present invention, and performs multiplexing and CPCS packet conversion for each different delay sensitive traffic group input and inputs different delay insensitive traffic group. AAL2 multiplexing process (S100) for performing multiplexing and CPCS packet conversion separately for the AAL2 multiplexing process (S100), and a cell generation timer having an appropriate length for delay sensitive CPCS packets converted in the above-described AAL2 multiplexing process (S100). AAL2 ATM cell generation by suppressing cell generation delay and generating an AAL2 ATM cell in a cell payload, and generating an AAL2 ATM cell by putting delay-insensitive CPCS packets converted in the AAL2 multiplexing process (S100) in a cell payload. The round robin method weights the delay sensitive AAL2 ATM cell and the delay insensitive AAL2 ATM cell generated in step S200 and the AAL2 ATM cell generation step S200. An AAL2 ATM cell multiplexing process (S300) for multiplexing according to comprise.

FIG. 4 is a flowchart for describing the AAL2 ATM cell multiplexing process S300 of FIG. 3 in detail. The AAL2 ATM cell multiplexing process S300 is performed in the AAL2 ATM cell multiplexer buffer 31 existing in each traffic group. Monitors cell presence to obtain standby cell presence information of each traffic group, and monitors load state of the AAL2 ATM cell multiplexer buffer 31 for the delay insensitive traffic group to obtain load state information of the delay insensitive traffic group. Cell multiplexing weight determination process for determining the weight value of each traffic group based on the monitoring process (S310), the standby cell presence state information obtained in the monitoring process (S310), and the load state information of the delay-insensitive traffic group. And a transmission cell for determining a transmission cell based on the weight value of each traffic group and the standby cell presence status information determined in the cell multiplexing weight determination process (S320). It comprises an information process (S330).

FIG. 5 is a flowchart for describing the transmission cell determination process (S330) of FIG. 4. The traffic group (buffer) indicated by the start pointer Start_Pointer using information on the presence or absence of a standby cell at each transmission cell determination time is shown. The traffic group (buffer) is searched from the next traffic group (buffer) in the order of round robin (S332), and it is determined whether there is a traffic group (buffer) in which the standby cell exists (S334).

When there is a traffic group (buffer) in which the standby cell exists, as a result of the determination of step S334, an order index is assigned to the traffic groups (buffers) in which the searched standby cell exists in the order close to the start pointer (S336).

Subsequently, when obtaining a random number from the random number table consisting of a plurality of random numbers stored in the random number storage ROM (not shown) (S338), when obtaining a random number from the random number table stored in the random number storage ROM (not shown), The random number at the location pointed to by the search pointer is read and output, and the search pointer is placed next to perform a sequential search in a round-robin fashion. Here, the random numbers are composed of a bit sequence of '0' or '1', and the number of bits of the random sequence to be compared with the weight of any traffic group (buffer) is called k, and the total number of input traffic groups (buffers) is k. When N is the number of delay sensitive traffic groups + M (the number of delay insensitive traffic groups), one random number of bits becomes k × (N + M).

Subsequently, the random numbers obtained in the above process S338 are separated by k bits by the number of traffic groups (buffers) in which the standby cell exists among all the bit sequences (S340), and the k-bit random numbers of the respective bits are '0'. And normalize to a value between '1' (S342).

Thereafter, the value normalized in step S342 is compared with the weight value of the traffic group (buffer) in which the standby cell exists one-to-one, and a random traffic group (buffer) having a random number smaller than the weight value is transmitted. In this case, it is determined whether there is a transmission traffic group candidate among all the input traffic groups (buffers) (S344, S346).

In step S346, when the traffic group having a random number smaller than the weight value is transmitted as a result of comparing the value normalized in step S344 with the weight value of the traffic group (buffer) in which the standby cell exists, one-to-one, respectively. If it is determined that there is a traffic group candidate, and there is no group having a random number smaller than the weight value, it is determined that there is no transmission traffic group candidate.

As a result of the determination in step S346, when there is no transmission traffic group candidate, the standby cell in the AAL2 ATM cell multiplexing buffer of the traffic group having the lowest order index located in the round robin direction from the start pointer is determined as the transmission cell ( S348). On the other hand, if the transmission traffic group candidate is present as a result of the determination in step S346, the standby cell in the AAL2 ATM cell multiplexing buffer of the transmission traffic group candidate having the lowest order index among the plurality of transmission traffic group candidates is determined as the transmission cell (S350). ).

As described above, when the transmission cell is determined through the above-described process S348 or S350, the start pointer is placed in the AAL2 ATM cell multiplexing buffer in which the transmission cell determined in the above-described process S348 or S350 is stored (S352).

6 is a diagram illustrating a configuration of an AAL2 ATM transmission apparatus according to another embodiment of the present invention, and the AAL2 ATM transmission apparatus according to another embodiment of the present invention multiplexes input packets of a delay sensitive traffic group and a delay insensitive traffic group. AAL2 multiplexer (50, 55) for performing CPCS packet conversion, and delay sensitive AAL2 ATM for generating AAL2 ATM cells while suppressing cell generation delay using a cell generation timer in consideration of delay requirements of delay sensitive traffic groups. A cell generator 60, a delay insensitive AAL2 ATM cell generator 65 for generating an AAL2 ATM cell containing delay insensitive CPCS packets of a delay insensitive traffic group in a cell payload, a delay sensitive AAL2 ATM cell and a delay insensitive AAL2 ATM cell AAL2 ATM cell multiplexer 70 is multiplexed according to a weighted round robin scheme.

Since the operation of the AAL2 ATM transmission apparatus according to another embodiment of the present invention shown in FIG. 6 is the same as the operation of the AAL2 ATM transmission apparatus according to the present invention described above, a detailed description thereof will be omitted.

The AAL2 ATM transmission apparatus and method of the present invention are not limited to the above-described embodiments, and can be implemented in various modifications within the scope of the technical idea of the present invention.

According to the AAL2 ATM transmission apparatus and method of the present invention as described above, performing AAL2 multiplexing for each traffic group for different input traffic groups having different delay characteristics, and suppressing the cell generation delay of the delay sensitive traffic group In order to perform cell generation by introducing a cell generation timer, the generated cells are multiplexed in a weighted round robin manner based on the load of each input traffic group and the delay requirement for each traffic group in a single cell multiplexer, thereby providing a multimedia service. By activating, it is possible to improve the link transmission efficiency of delay sensitive traffic groups and delay sensitive traffic groups that occur with various delay requirements.

Claims (6)

A plurality of AAL2 multiplexers which perform multiplexing and common part convergence sublayer (CPCS) packet conversion on each of different delay sensitive traffic group and delay insensitive traffic group inputs; By using a cell generation timer, delay-sensitive CPCS packets received from each of the corresponding AAL2 multiplexers are suppressed from the cell generation delay and included in the cell payload to generate delay-sensitive AAL2 ATM cells, and delay-insensitive CPCS packets are generated by the cell payload. A plurality of AAL2 ATM cell generation units for generating delay insensitive AAL2 ATM cells; And an AAL2 ATM cell multiplexer configured to multiplex the delay sensitive AAL2 ATM cell received from the AAL2 ATM cell generator and the delay insensitive AAL2 ATM cell according to a weight-based round robin scheme. The method of claim 1, wherein the cell generation timer, And a cell generation time is set through prediction of a maximum value of a packet arrival rate for preventing packet division and a delay requirement of a corresponding traffic group. The method of claim 1, wherein the AAL2 ATM cell multiplexer, Each delay sensitive traffic group and delay insensitive traffic group are provided one by one to temporarily store the AAL2 ATM cells received from the AAL2 ATM cell generation unit, and before each cell transmission time, respectively, the delay sensitive traffic group and delay insensitivity. A buffer unit for monitoring the presence or absence of standby cells in the traffic group and monitoring the number of standby cells in each of the delayed and insensitive traffic groups; A buffer state monitoring unit managing standby cell presence status information of each delay sensitive traffic group and delay insensitive traffic group and load state information of the delay insensitive traffic group based on the status information of each buffer received from the buffer unit; For each delay sensitive traffic group and the delay insensitive traffic group based on the standby cell presence status information of each delay sensitive traffic group and the delay insensitive traffic group and load state information of the delay insensitive traffic group received from the buffer status monitoring unit. A cell multiplexing weight determination unit determining a weight value; And a cell multiplexing unit configured to multiplex by determining a transmission cell in a weight based round robin manner based on the weight value of each traffic group received from the cell multiplexing weight determining unit and information on standby cell presence of each traffic group. ALS2 AT transmission device. AAL2 multiplexing for performing multiplexing and Common Part Convergence Sublayer (CPCS) packet conversion for each of the different delay sensitive traffic group and delay insensitive traffic group inputs; The delay-sensitive CPCS packets transformed in the AAL2 multiplexing process are suppressed by using a cell generation timer to suppress a cell generation delay, and a delay-sensitive AAL2 ATM cell is generated by putting them in a cell payload, and delay-insensitive CPCS packets are stored in a cell payload. Generating an AAL2 ATM cell for generating an AAL2 ATM cell; And an AAL2 ATM cell multiplexing step of multiplexing the delay sensitive AAL2 ATM cell and the delay insensitive AAL2 ATM cell according to a weight-based round robin scheme. The method of claim 4, wherein the AAL2 ATM cell multiplexing process, Immediately before each cell transmission time, the presence or absence of standby cells of each delay sensitive traffic group and the delay insensitive traffic group is monitored, and the number of standby cells of each delay insensitive traffic group is monitored so that the standby cell presence information and delay insensitivity of each traffic group are monitored. A monitoring process of obtaining load state information of the traffic group; A weight determination process of determining a weight value of each traffic group based on standby cell presence information of each traffic group and load state information of the delay-insensitive traffic group; And a transmission cell determination process of determining and multiplexing a transmission cell in a weight-based round robin based on the determined weight value and standby cell presence information of each traffic group. The method of claim 5, wherein the transmission cell determination process, Searching the traffic groups in the order of round robin from the next traffic group of the traffic group indicated by the start pointer based on the standby cell presence information of each traffic group to determine whether there is a traffic group in which the standby cell exists; When the traffic group in which the standby cell exists exists as a result of the determination, assigning an order index to the traffic groups in which the searched standby cell exists in an order close to the start pointer; Obtaining a random number from a random number table stored in the random number storage ROM, and separating the obtained random number by k bits by the number of traffic groups in which a standby cell exists, and normalizing the random number to a value between '0' and '1'; Comparing the normalized value one-to-one with a weight value of a traffic group in which a standby cell exists, setting a traffic group having a random number smaller than the weight value as a transmission traffic group candidate, and determining whether a transmission traffic group candidate exists; ; As a result of the determination, if there is no transmission traffic group candidate, the cell of the traffic group having the lowest order index is determined as the transmitting cell. If there is a transmission traffic group candidate, the transmission traffic group having the lowest order index among the transmission traffic group candidates is determined. Determining a cell of the candidate as a transmitting cell; And positioning a start pointer in a traffic group in which the determined transmission cell is stored.