JPH1188466A - Data transmission device/reception device with retransmission request - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the increase delay generated between transmission and reception by abolishing data on a block from transmission data when the delay quantity of the monitored block exceeds a setting value. SOLUTION: A delay quantity monitoring part 270 monitors the delay quantity of the data block in respective buffers 240, 250 and 260. The respective buffers 240-260 have timers for measuring time from data block input and report time to the delay quantity monitoring part 270 as delay information. The delay quantity monitoring part 270 compares delay information from the respective buffers 240-260 with an upper limit value and abolishes the data block exceeding the upper limit. Namely, the buffer where the data block abolished by data block abolishment information 270a is informed to a write control part 220. The write control part 220 updates head position information so that the data block to which abolishment is informed by data block abolishment information 270a is not outputted as generated data block 200b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for controlling an error in transmitted data in data communication.

[0002]

2. Description of the Related Art One of the methods for removing an error occurring during communication is an automatic repeater (ARQ).
t Request, automatic retransmission request) method. AR
Q is a control method for retransmitting a data unit (frame) containing an error and removing the error. About ARQ,
“Automatic Repeat Request
Error-Control Schemes "(Sh
u Lin et al., IEEE Commun. Mag. , Vo
l. 22, no. 12, Dec. '84).

FIG. 11 schematically shows the basic operation of ARQ.
In the figure, the crosses in the D received frame indicate poor reception. The arrow from the reception frame D to the transmission frame C indicates the backward line from the reception station, and P such as P1 on the arrow indicates Positive Acknowledge.
Indicates an edge, and indicates that no reception failure has occurred in the received frame. N such as N2 and N4 is Nega
Indicates active acknowledgment and indicates that a reception failure has occurred in a received frame. In the example shown in the figure, P1 means a response confirmation for the frame of sequence number 1. N2 means that the response to the frame of the sequence number 2 has not been confirmed, and it becomes a retransmission request for the corresponding frame. First, on the transmitting side, when data is input, the transmitting station divides the data into frames, which are transmission units, and stores the data in a transmission buffer. At the transmission timing, if there is no retransmission request from the receiving station, the transmitting station extracts data in frame units in the transmission buffer in the order of storage, performs transmission processing such as error detection coding, and then transmits the transmission frame. When a retransmission request is received from the receiving side, a retransmission corresponding to a transmission frame is inserted.
The retention shown in 1B will occur. The receiving station performs error detection on the received frame, and if no error is detected, stores the error in the reception buffer. As a result of the above error detection,
If an error is detected in the received frame, the sequence number of the frame is stored in the retransmission request buffer. In the case of FIG. 11, when a retransmission request (N2 or the like) is transmitted, it is not stored in the retransmission request buffer because it does not need to be stored, and if another retransmission request occurs until correct retransmission is received, it is stored. The timing from the transmission frame to the reception is displayed at two timings. The reception buffer outputs the data as the data when the reception frames are arranged according to the sequence number in the block.

FIG. 12 shows a configuration example of a conventional general ARQ transmitting station. In the figure, 10 is a retransmission request determination unit, 2
0 is a transmission buffer unit, 30 is a transmission processing unit, 40 is a retransmission buffer unit, and 50 is a logical sum. 10a is a backward signal, 10b is a retransmission request signal, 20a is generated data, 20b is a generated data block, 30a is a generated frame, 40a is a retransmission frame, and 50a is a transmission frame. When the retransmission request determination unit 10 confirms the retransmission request from the receiving station by the backward signal 10a, the retransmission request signal 1
0b is output. The transmission buffer unit 20 stores the generated data 20
a is divided into data blocks in frame units and stored. The transmission buffer unit 20 outputs the internal data blocks as the generated data blocks 20b in the order of storage, but stops the output of the generated data blocks 20b when the retransmission request signal 10b is confirmed. When the generated data block 20b is input, the transmission processing unit 30 performs framing processing such as error detection coding and outputs a generated frame 30a. The retransmission buffer unit 40 stores a copy of the transmission frame until a response to the transmission frame is confirmed. Also, it outputs a retransmission frame 40a in response to the retransmission request signal 10b. The OR 50 outputs one of the generated frame 30a and the retransmission frame 40a controlled by the retransmission request signal 10b as the transmission frame 50a.

FIG. 13 shows a configuration example of a conventional general ARQ receiving station. In the figure, 60 is an error detection unit, 70 is a reception buffer unit, 80 is a sequence number storage unit, 90 is a retransmission request buffer unit, and 100 is a backward signal generation unit. Also, 60a is a received frame, 60b is a significant frame, 60c is an error detection sequence number, 70a is received data,
80a is a response confirmation sequence number, 90a is a retransmission request sequence number, and 100a is a response confirmation frame. Error detector 6
0 detects an error in the received frame 60a, and outputs a significant frame 60b if no error is detected. When an error is detected in the received frame 60a, the sequence number of the frame is output as an error detection sequence number 60c. The reception buffer unit 70 stores the input significant frame 60b therein. When the order numbers of the significant frames are aligned, the data portion is extracted and the received data 70a is sequentially output. The sequence number storage unit 80 extracts the sequence number of the significant frame 60b. If this value is larger than the sequence number stored before, the response confirmation sequence number 80a is updated to the sequence number. The retransmission request buffer unit 90 sets the minimum value of the input error detection sequence numbers 60c to the retransmission request sequence number 9c.
Output as 0a. If the retransmission request sequence number 90a is input, the backward signal generation unit 100 outputs a retransmission request for the frame, and if the signal is not input, outputs a response confirmation corresponding to the response sequence number 80a.

FIG. 14 shows a detailed configuration example of the transmission buffer unit 20 in FIG. In the figure, 21 is a data dividing unit,
22 is a write control unit, 23 is a read control unit, 24, 2
Reference numerals 5 and 26 are buffers. 10b is a retransmission request signal, 20a is generated data, 20b is a generated data block, 21a is a data block, 22a is buffer head position information, 22b is write position information, and 23a is read position information. The data division unit 21 divides the generated data 20a input from the outside into data blocks in frame units, and outputs the data blocks 21a. The write controller 22 outputs the write position information 22b and selects the write position of the data block 21a from the buffers 24 to 26. The block updates the oldest write buffer position using the read position information 23a, and notifies the read control unit 23 of the position using the buffer head position information 22a. The read control unit 23 performs buffer head position information 2
The buffer position to be read by 2a is selected from buffers 24 to 26, and the generated data block 20b is output from the transmission buffer unit 20. However, the retransmission request signal 10
When b is input, control is performed so that the generated data block 20b is not output. As described above, this block unit cannot output a newly generated data block when there is a retransmission request. For this reason, if a retransmission request occurs frequently, the number of data blocks reserved inside the block increases, causing a delay occurring between the transmitting and receiving stations.

[0007] In the operation performed by the apparatus having the configuration shown in FIG. 14, a delay generated in the transmission buffer will be described with reference to FIG. In the figure, 27a, 27b and 27c are data blocks. The signals H to J indicate signals at the corresponding number positions in FIG. It is assumed that no delay occurs in the data block 27a. The figure shows a case where an error has occurred and the data block 27b is retained in the buffer due to the occurrence of the retransmission request signal 10b, and a delay corresponding to two data blocks has occurred. In this case, the three buffers are accumulated in the buffers 24, 25, and 26 of J, and after the retransmitted DB2 is output in the generated data block (output) 20b of K, if there is no subsequent data, the data is reduced. Thus, data block 2
7c has a delay equivalent to two data blocks because there is a data block reserved by a retransmission request that has occurred previously. As described above, the influence of the delay due to the retransmission request in the block affects data blocks after the occurrence.

FIG. 16 shows a detailed configuration example of the reception buffer unit 70 in FIG. In the figure, 71 is a data extraction unit,
72 is a write control unit, 73 is a read control unit, 74 is a sequence number storage unit, and 75, 76, and 77 are buffers. Also, 60b is a significant frame, 70a is received data, 71
a is a sequence number, 71b is a data block, 72a is buffer top position information, 72b is write position information, 73a is read position information, and 74a is a significant frame number. The data extracting unit 71 extracts the sequence number and the data block from the significant frame 60b and outputs the sequence number 71a and the data block 71b. The write control unit 72 has a sequence number 71
The write buffer is selected based on the relative value between a and the sequence number of the data block stored in the first buffer, and the write position information 72b is output. The read control unit 73 can know the frame number of the received data 70a output from this block from the significant frame number 74a. The read control unit 73 starts reading control from the buffer when the sequence number of the data block stored in the first buffer is greater than the significant frame number 74a by one.
Reading is performed until an empty buffer is detected. The read control unit 73 outputs read position information 73a according to the above control. The sequence number storage unit 74 stores the sequence number of the last output data block according to the operation of the read control unit 73. Buffers 75 to 77 have write position information 72
The data block 71b is stored according to a, and the received data 70a is output according to the read position information 73a. As described above, this block reserves the data block of the received frame without error until the sequence numbers are aligned. For this reason, when retransmission of an arbitrary frame occurs continuously or when retransmission frequently occurs, the delay of the data block reserved in this block increases.

The delay occurring in the reception buffer in the operation performed by the apparatus having the configuration shown in FIG. 16 will be described with reference to FIG. In the figure, 78a, 78b, 78c, 78
d and 78e are received frames. The signals L to 0 indicate the signals at the corresponding number positions in FIGS. 13 and 16 with respect to the time axis. In addition, 1 to 10 in a rectangular frame represent each data block, and the same number represents the same data block. In the figure, the reception frames 78a, 78
The numbers 8b, 78c, 78d, and 78e represent the sequence numbers, and it is assumed that an error has occurred in the received frames 78b and 78d. Since the received frame 78a arrives according to the sequence number, no delay occurs in the block. The received frame 78b is not stored in the buffer because an error has occurred. The received frame 78c is stored in the buffer of the block since the frame having the sequence number 2 is not output as the received data. The frame is retained in the buffer until the received frame having the sequence number 2 is received without error. Therefore, the data is output as the reception data after waiting until the reception frame 78e, and a delay corresponding to 7 reception frames occurs in the block.

FIG. 18 shows a detailed configuration example of the retransmission request buffer unit in FIG. In the figure, 91 is a write control unit,
92 is a read control unit, and 93, 94 and 95 are buffers. 60c is an error detection order number, 90a is a retransmission request order number, 91a is buffer head position information, 91b is write position information, and 92a is read position information. Here, the write control unit 91, the read control unit 92, and the buffer head position information 91a, the write position information 91b, and the read position information 92a correspond to the write control unit 22, the read control unit 23, and the buffer in FIG. Since they are the same as the start position information 22a, the write position information 22b, and the read position information 23a, the description is omitted. The buffers 93 to 95 receive the error detection sequence number 60c according to the write position information 91b. Further, it outputs the retransmission request sequence number 90a according to the read position information 92a.

Referring to FIG. 19, a description will be given of a delay caused by an increase in retransmission requests in an operation performed by the apparatus having the configuration shown in FIGS. In the figure, 96a, 96
b, 96c, 96d, 96e and 96f are received frames. The signals P to S indicate the signals at the corresponding numbered positions in FIGS. 13, 16, and 18 with respect to the time axis. Numerals 1 to 13 in a rectangular frame represent each data block, and the same number represents the same data block. In the figure, the received frames 96a, 96b,
The numbers 96c, 96d, 96e, and 96f represent the sequence numbers, and it is assumed that an error has occurred in the received frames 96b, 96d, and 96e. Since the received frame 96a arrives according to the sequence number, no delay occurs. The reception frame 96c is stored in the reception buffer until the frame of the sequence number 2 is received without error, so that a delay equivalent to four reception frames occurs. On the other hand, the reception frame 96f is stored in the reception buffer until the frames of order numbers 6 and 8 are received without error, so that a delay corresponding to 5 reception frames occurs.

[0012]

In the error control system based on the conventional ARQ, retransmission is continued until an error in a frame is eliminated in order to transmit data between a transmitting station and a receiving station without error. Therefore, the above-mentioned method has a problem that if retransmission frequently occurs due to deterioration of a line state, a delay generated between transmission and reception increases. On the other hand, at the application level, requirements for communication quality such as an error rate and a delay amount differ depending on each data characteristic such as image data and audio data.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and by allowing a certain amount of error, that is, discarding retransmission request data exceeding a certain standard, reducing delay and expanding the delay distribution. It is an object of the present invention to obtain a data transmission device having a small value.

[0014]

According to the present invention, there is provided a data transmission / transmission apparatus with a retransmission request, which transmits data in units of blocks and retransmits in units of blocks when an error occurs. A transmission buffer unit that holds until transmission in block units, a delay amount monitoring unit that monitors the delay amount of each block of the transmission buffer unit, and a delay amount of the monitored block that exceeds a set value. Transmission control means for discarding data from transmission data.

Furthermore, the delay amount monitoring unit has a timer,
When a block of untransmitted data in the transmission buffer stays for a predetermined time or longer, discard instruction information is output to the transmission control means.

A data transmission / reception apparatus with a retransmission request according to the present invention is a data transmission / reception apparatus for receiving data in block units and requesting retransmission in block units in the event of an error. A reception buffer unit that holds the data until they are aligned, a delay amount monitoring unit that monitors the delay amount of each block of the reception buffer unit, and data that excludes the block when the delay amount of the monitored block exceeds a set value. And reception control means for outputting the same.

Alternatively, in a data transmission receiving apparatus which receives data in units of blocks and requests retransmission in units of blocks for an occurrence error, the data transmission receiving apparatus holds a retransmission request for an erroneous block until a predetermined timing. A buffer amount monitoring unit that monitors a delay amount of each block of the retransmission request buffer unit, and a retransmission request of the buffer when the delay amount of the monitored buffer exceeds a set value. Receiving control means for stopping and outputting data excluding the corresponding block.

Further, the delay amount monitoring unit or the buffer amount monitoring unit notifies the reception control unit to stop the data output or the retransmission request when the number of blocks to be monitored exceeds the predetermined number. did.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1 FIG. Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a configuration diagram of a data transmission / transmission apparatus with a retransmission request according to the present embodiment. In the figure, 200 is a transmission buffer unit, 200b is a generated data block, and the others are the same as or equivalent to the elements of the same numbers shown in FIG. Transmission buffer unit 200
Divides the generated data 20a into data blocks in frame units and stores them. The transmission buffer unit 200 outputs the internal data blocks as the generated data blocks 200b in the order of storage. When the retransmission request signal 10b is confirmed, the transmission buffer unit 200 stops outputting the generated data blocks 200b. Further, the transmission buffer unit 200 internally has a delay detection method, and stops the output as the generated data block 200b when the delay amount of the stored data block exceeds the reference value. Other operations are the same as those of the apparatus having the configuration shown in FIG.

Hereinafter, the transmission operation of the apparatus having the configuration shown in FIG. 1 will be described. FIG. 2 shows a detailed configuration of the transmission buffer unit 200 in FIG. In the figure, 220 is a write control unit, 24
Reference numerals 0, 250, and 260 denote buffers, and reference numeral 270 denotes a delay amount monitoring unit that monitors delay amounts of data blocks in the individual buffers 240, 250, and 260. 200b is a generated data block, 220a is buffer head position information, 22
0b is writing position information, 240a, 250a, 260a
Is buffer delay information, and 270a is data block discard information. Others are the same as or equivalent to the elements of the same numbers shown in FIG. Each buffer has a timer for measuring the time from the input of the data block, and reports this to the delay monitor 270 as delay information. Delay monitor 27
0 compares the delay information from each buffer with the upper limit and discards data blocks exceeding the upper limit. More precisely, the buffer storing the data block discarded by the data block discard information 270a is stored in the write control unit 2.
Notify 20. The write control unit 220 updates the head position information 220a so that the data block notified of the discard by the data block discard information 270a is not output as the generated data block 200b.

FIG. 3 shows an example of the control operation. In the figure,
280a, 280b and 280c are buffers 24 in FIG.
Data blocks in 0, 250, 260, etc. The signals a, b, and d in the figure indicate signal examples at the corresponding number positions in FIG. FIG. 3 is an explanatory timing chart showing the control operation of the present invention when an error of the same condition as in FIG. 15 occurs. In the control shown in the figure, the upper limit of the reservation of the data block is equivalent to two data blocks. In FIG. 2, the number of buffers is three (B1,
B2, B3). When B1, B2, and B3 are all empty, the write control unit 23 and the read control unit 2
20 designates B1 as a data write destination.
In FIG. 3, when there is generated data 20a, the data is divided into buffer sizes and stored in the order of B1 and B2. That is, first, the data DB1 stores the buffer B1 24
0 is stored. At this time, the writing control unit 23 moves the pointer to the buffer B2 250 which is the next writing position. Since the data DB1 is transmitted immediately after being stored in the buffer B1 240, no delay occurs. In addition, the read control unit 220 determines whether the buffer B2
Move the pointer to 250. The data DB2 is stored in the buffer B2 250. The pointer of the write control unit 23 points to B3, and the pointer of the read control unit 220 is B2.
Point to 2. Next, when data X indicated by a white frame in the figure is input to the buffer, the pointer of the write control unit 23 points to B1, and the pointer of the read control unit 220 points to B2. At time t2, another data is input after a further elapse of one timing, and at time t2, the hold time of data DB2 elapses for two operation timings, and DB2 is discarded from the buffer. Thus, the generated data block 20 of the two displays of FIG.
0b time series data is obtained. By this control, the delay of the data block 280c is equivalent to one data block, and the delay amount is smaller than that of the data block 27c in FIG.

In the configuration described above, the delay amount monitoring unit monitors the delay of the operation timing from the buffer.
The time of the buffer switching operation may be monitored,
The buffer overflow may be detected by inputting more data than the number of buffers prepared.

Embodiment 2 FIG. Although the data transmitting apparatus has been described in the first embodiment, the present invention may be applied to a receiving apparatus. FIG. 4 shows a configuration diagram of a data transmission / reception device as another embodiment of the present invention. In the figure, 700 is a reception buffer unit, and 700a is reception data. Others are shown in Figure 1
4 is the same as or equivalent to the element of the same number described in 4. The reception buffer unit 700 stores the input significant frame 60b therein. When the order numbers of the significant frames are aligned, the data portion is extracted and the received data 700a is sequentially output. In addition, the reception buffer unit 700 has a delay detection method therein, and when the delay amount of the stored data block exceeds the reference value, stops the retransmission wait of the data block having the sequence number smaller than the data block. , And outputs the data block from the data block to the data block with the same sequence number as the received data 700a. Other operations are the same as those described with reference to FIG.

The receiving operation of the device having the configuration shown in FIG. 4 will be described below. FIG. 5 shows a detailed configuration of the reception buffer unit 700 in FIG. In the figure, reference numeral 720 denotes a write control unit;
0 is a sequence number storage unit, 750, 760, and 770 are buffers, and 780 is a delay amount monitoring unit.
Monitor the delay of the data block at 760,770. 700a is received data, 720a is buffer top position information, 720b is write position information, 740a is a significant frame number, 750a, 760a, and 770a are buffer delay information, and 780a is a discard sequence number. The rest is the same as the configuration of FIG. Each buffer has a timer that measures the time from when the data block is input, and reports this to the delay monitor 780 as delay information. The delay amount monitoring unit 780 compares the delay information from each buffer with the upper limit value, and outputs from the data block exceeding the upper limit to the data block with the same sequence number as the received data 700a. More correctly, the sequence number storage unit 740 is notified of a value smaller by 1 than the sequence number of the data block exceeding the upper limit of the delay in the discard sequence number 780a. The sequence number storage unit 740 updates the significant frame number 740a to the notified discard sequence number 780a.

FIG. 6 shows an example of the control operation. In the figure,
790a, 790b, 790c, 790d, and 790e are received frames. The signals E, G, and J in the figure are
6 shows an example of a signal at a corresponding number position in FIGS. 4 and 5. FIG. 6 is an explanatory timing chart showing the control operation of the present invention when an error of the same condition as in FIG. 17 occurs. In the control shown in the figure, the upper limit value of the reservation of the data block is equivalent to 5 received frames. Also, in the figure, the numbers of the received frames 790a to 790e represent the sequence numbers, and it is assumed that an error has occurred in the received frames 790b and 790d. The reason why no delay occurs in the received frame 790a of FIG. 6 in the timing explanatory diagram of FIG. 6 is that there is no error in the received frame 790a and that the frame is immediately output, which is the same as FIG. At the next timing, since an error has occurred in the received frame 790b,
Do not store in buffer. The received frame 790c is stored in the buffer of the block since the frame having the sequence number 2 is not output as the received data. At this time,
Start timer operation. Since the data block 790b has been reserved for 5 reception frames in the block at the time t2, the delay exceeds the set delay, and the subsequent sequence numbers stored in the buffer are aligned. The received data block is output as received data. By this control, the delay of the data block 790c is equivalent to 5 received frames, and the delay amount is smaller than that of the data block 78c in FIG.

In the configuration described above, the delay amount monitoring unit counts the operation timing from the buffer. However, even if the number of received frames during that time is counted and the number of received frames exceeds a predetermined value, the received data is not output. The delay may be detected, or the delay may be detected due to the reception data overflow exceeding a predetermined number of buffers as in the transmission.

Embodiment 3 A case where the present invention is applied to another data transmission receiving device will be described. FIG. 7 is a configuration diagram of the receiving apparatus. In the figure, 7000 is a reception buffer unit, 800 is a sequence number storage unit, and 900 is a retransmission request buffer. Also, 7000a is the received data, 800a is the response confirmation sequence number, 900a is the retransmission request sequence number, 90a
0b is a discard sequence number. Others are the same as or correspond to the same-numbered elements shown in FIG. The retransmission request buffer unit 900 receives the input error detection sequence number 60c
Among them, the minimum value is output as the retransmission request sequence number 900a. Further, the retransmission request buffer unit 900 monitors the buffer amount, and when the buffer amount exceeds the reference value, stops the retransmission request for the stored sequence number. For example, the discard sequence number 900b is output to notify the sequence number storage unit 800 and the reception buffer unit 7000. The order number storage unit stores the discard order number 900b as the response confirmation order number 8
If it is larger than 00a, the response confirmation sequence number 800a is updated. The reception buffer unit 7000 stores the reception data 7000
At the time of output of a, the data block in the buffer is output on the assumption that the unacknowledged data block having the sequence number smaller than the discard sequence number 900b is discarded.

Hereinafter, the receiving operation of the device having the configuration shown in FIG. 7 will be described. FIG. 8 shows a detailed configuration of the retransmission request buffer 900 in FIG. In the figure, 920 is a read control unit, 9
60 is a buffer amount monitoring unit, 930, 940, and 950 are buffers, 900a is a retransmission request sequence number, 900b
Is a discard sequence number, 920a is read position information, and 930
a, 940a and 950a are buffer data, and 960a is read control information. Others are the same as those of the same numbers described in FIG. The buffer amount monitoring unit 960 monitors the number of retransmission requests stored in the buffers 930, 940, and 950, and if this value exceeds the upper limit, stops all retransmission requests stored in the buffer. More precisely, read control information 960a is output, and the read operation of read control unit 920 is stopped. Further, the buffer amount monitoring unit 960 outputs the maximum value of the sequence number among the stopped retransmission requests as 900b.

FIG. 9 shows the reception buffer section 700 in FIG.
0 shows a detailed configuration. In the figure, reference numeral 7300 denotes a read control unit, 900b denotes a discard sequence number, and 7000a denotes received data. Others are the same as those of the same numbers described in FIG. Read control unit 7300 discards sequence number 9
If 00b is not input, the operation is the same as in FIG. When the discard sequence number 900b is input, the reading control unit 7300 performs a reading operation assuming that the corresponding frame is discarded, without waiting for retransmission of a frame having a sequence number smaller than the discard sequence number.

FIG. 10 shows an example of the control operation. In the figure, 960a, 960b, 960c, 960d, 960
e and 960f are received frames. 7 and 9 show signal examples at the corresponding number positions in FIGS. FIG. 10 is a timing chart showing the control operation of the present invention when an error of the same condition as in FIG. 19 occurs. In the control in the figure, the upper limit of the reservation of the retransmission request is set to 0. Receive frames 960a, 96
The numbers 0b, 960c, 960d, 960e, and 960f represent the sequence numbers, and the received frames 960b,
It is assumed that an error has occurred in 60d and 960e. In the timing explanatory diagram of FIG.
The reason why no delay occurs is that the output is immediately made assuming that there is no error, for the same reason as in FIG. by the way,
In the case of FIG. 10, the upper limit of the reservation is 0, and no retransmission is requested by the control of the retransmission request buffer even if an error is detected in the received frame 960e. Therefore, the reception frame 96
0f is output as received data when the frame of the reception number 6 is received without error, and the delay is equivalent to one received frame.

[0031]

Since the present invention is configured as described above, it is possible to prevent an increase in delay occurring between transmission and reception and to perform error control suitable for communication requiring real-time transmission such as voice transmission. There is.

Further, since it is possible to prevent the distribution of delay occurring between transmission and reception from being widened, there is an effect that error control with little fluctuation due to delay can be performed.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a data transmission / transmission apparatus according to Embodiment 1 of the present invention.

FIG. 2 is a detailed configuration diagram of a transmission buffer unit according to the first embodiment.

FIG. 3 is a diagram illustrating an operation of the transmission buffer unit of FIG. 2;

FIG. 4 is a configuration diagram of reception of a data transmission / transmission apparatus according to Embodiment 2 of the present invention.

FIG. 5 is a detailed configuration diagram of a reception buffer unit according to the second embodiment.

FIG. 6 is a diagram illustrating the operation of the reception buffer unit of FIG.

FIG. 7 is a configuration diagram of a data transmission / reception device according to Embodiment 3 of the present invention.

FIG. 8 is a diagram illustrating a configuration in which a retransmission request buffer unit according to Embodiment 3 is omitted.

FIG. 9 is a detailed configuration diagram of a reception buffer unit according to the third embodiment.

FIG. 10 is a diagram illustrating the operation of a retransmission request buffer unit and a reception buffer unit in FIGS. 8 and 9;

FIG. 11 is a diagram illustrating the concept of ARQ.

FIG. 12 is a configuration diagram of a conventional data transmission / transmission device.

FIG. 13 is a configuration diagram of a conventional data transmission / reception device.

FIG. 14 is a detailed configuration diagram of a transmission buffer unit in a conventional data transmission transmission device.

FIG. 15 is a diagram illustrating a delay that occurs in a transmission buffer unit of a conventional data transmission transmission device.

FIG. 16 is a detailed configuration diagram of a reception buffer unit in a conventional data transmission / reception device.

FIG. 17 is a diagram illustrating a delay that occurs in a reception buffer unit of a conventional data transmission reception device.

FIG. 18 is a detailed configuration diagram of a retransmission request buffer unit in a conventional data transmission / reception device.

FIG. 19 is a diagram illustrating a delay caused by an increase in retransmission requests in a conventional data transmission / reception device.

[Explanation of symbols]

10 retransmission request determination unit, 20 transmission buffer unit, 30
Transmission processing unit, 40 retransmission buffer unit, 50 logical sum, 6
0 error detection unit, 70 reception buffer unit, 80 sequence number storage unit, 90 retransmission request buffer unit, 100 backward signal generation unit, 21 data division unit, 22 write control unit, 23 read control unit, 24 buffer, 25 buffer, 26 buffers, 71 data extraction unit, 72
Write control unit, 73 read control unit, 74 sequence number storage unit, 75 buffers, 76 buffers, 77 buffers, 91 write control units, 92 read control units, 93 buffers, 94 buffers, 95 buffers, 220 write control units, 240 buffers , 250 buffers, 26
0 buffer, 270 delay amount monitoring unit, 700 reception buffer unit, 7000 reception buffer unit, 800 sequence number storage unit, 900 retransmission request buffer, 960 buffer amount monitoring unit, 930 buffer, 940 buffer, 9
50 buffer, 10a backward signal, 10b
Retransmission request signal, 20a generated data, 20b generated data block, 30a generated frame, 40a retransmitted frame, 50a transmitted frame, 60a received frame,
60b significant frame, 60c error detection sequence number, 7
0a Received data, 80a Response confirmation sequence number, 90a
Retransmission request sequence number, 100a response confirmation frame, 2
1a data block, 22a buffer head position information, 22b write position information, 23a read position information, 27a data block, 27b data block, 27c data block, 71a sequence number, 71
b data block, 72a buffer head position information,
72b Write position information, 73a Read position information, 7
4a Significant frame number, 78a Received frame, 78
b received frame, 78c received frame, 78d received frame, 78e received frame, 91a buffer head position information, 91b write position information, 92a read position information, 96a received frame, 96b received frame, 96c received frame, 96d received frame,
96e received frame, 96f received frame, 200
b generated data block, 220a buffer head position information, 220b write position information, 240a buffer delay information, 250a buffer delay information, 260a buffer delay information, 270a data block discard information,
280a data block, 280b data block, 280c data block, 700a received data, 790a received frame, 790b received frame, 790c received frame, 790d received frame,
790e received frame, 7000a received data, 8
00a Response confirmation sequence number, 900a Retransmission request sequence number, 900b Discard sequence number, 920a Read position information, 930a buffer data, 940a buffer data, 950a buffer data, 960a Read control information, 960a receive frame, 960b receive frame, 960c receive frame , 960d received frame, 960e received frame, 960f received frame.

Claims (5)

[Claims] 1. A data transmission and transmission apparatus for transmitting data in units of blocks and retransmitting in case of an error occurring in units of blocks, comprising: a transmission buffer unit for holding transmission data until transmission in units of blocks; A delay amount monitoring unit that monitors a delay amount of the block; and a transmission control unit that discards data of the corresponding block from transmission data when the delay amount of the monitored block exceeds a set value. Data transmission / transmission device with a retransmission request to be sent. 2. The delay amount monitoring unit has a timer, and outputs discard instruction information to a transmission control unit when a block of untransmitted data in a transmission buffer unit stays for a predetermined time or more. Item 2. A data transmission / transmission apparatus with a retransmission request according to item 1. 3. A data transmission receiving apparatus for receiving data in units of blocks and requesting retransmission in units of blocks in the event of an error, comprising: a receiving buffer unit for holding received data until the order is made in units of blocks; A delay amount monitoring unit that monitors a delay amount of each block of the unit, and a reception control unit that outputs data excluding the block when the delay amount of the monitored block exceeds a set value. A data transmission / reception device accompanied by a retransmission request. 4. A data transmission receiving apparatus for receiving data in units of blocks and requesting retransmission in units of blocks when an error occurs, wherein the data transmission receiving apparatus holds a retransmission request for a block in which an error has occurred until a predetermined timing. A buffer amount monitoring unit that monitors a delay amount of each block of the retransmission request buffer unit, and a retransmission request of the buffer when the delay amount of the monitored buffer exceeds a set value. A data transmission / reception device with a retransmission request, comprising: reception control means for stopping and outputting data excluding a corresponding block. 5. A delay amount monitoring unit or a buffer amount monitoring unit notifies a reception control unit to stop data output or a retransmission request when the number of monitored blocks exceeds a predetermined number. 4. The method according to claim 3, wherein
5. A data transmission / reception device with a retransmission request according to claim 4.