JP2009206846A - Data communication retransmission control method, and transmitting/receiving device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform communication processing by dynamically changing transmission/reception processing time (delay time in a device) of communication data, to accelerate transmission/reception processing of the communication data to raise throughput regarding a data communication retransmission control method and a transmitting/receiving device. <P>SOLUTION: In a transmitting side device 1-10, a communication data parameter indicating data processing characteristics such as a data amount or data length of the communication data is recognized by a delay time calculation part 1-11 in the transmitting side device, transmission processing time is dynamically calculated according to the communication data parameter, and a retransmission control part 1-12 performs transmission processing of the communication data within the transmission processing time to transmit the communication data to a receiving side device 1-20. The receiving side device 1-20 is notified of the transmission processing time at the time. The receiving side device 1-20 dynamically calculates reception processing time according to the communication data parameter, performs reception processing of the communication data within the reception processing time, replies response data to the transmitting side device, and simultaneously notifies the transmitting side device 1-10 of the reception processing time. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a data communication retransmission control method and a transmission / reception device, and more particularly, to a data communication retransmission control method and a transmission / reception device that perform retransmission control based on transmission delay times (RTT) of transmission side and reception side devices. About.

  In recent years, due to an increase in traffic such as voice data and image data, further improvement of the actual throughput in the network is required. Here, the actual throughput is the throughput of the effective data portion for the opposite device excluding the invalid data portion in the data communication signal, the communication data for other devices, and the like.

  In a wireless communication system such as a W-CDMA (Code Division Multiple Access) system or an OFDMA (Orthogonal Frequency Division Multiplexing) system, the conventional communication data transmission / reception process is a communication data transmission / reception process time in each device on the transmission side and the reception side. (Ie, transmission delay time) is set in advance as a fixed value, and communication data is transmitted / received in accordance with the preset fixed transmission / reception processing time (transmission delay time). The fixed transmission / reception processing time (transmission delay time) is set based on the value (data amount, data length, etc.) at the maximum load of communication data.

  An example of communication processing in a wireless interface between conventional transmission / reception apparatuses will be described with reference to FIGS. FIG. 7 shows a functional unit related to retransmission control of a conventional transmission / reception device, FIG. 8 shows a sequence of retransmission operation performed in a conventional fixed processing time, and FIG. 9 shows communication data in a conventional fixed transmission / reception processing time. The transmission / reception sequence and retransmission buffer management mode are shown.

  In FIG. 7, device A will be described as a transmitting device, and device B as a receiving device. In addition, although the process in each apparatus A and B is limited and limited to either the transmission or reception process, each apparatus A and B may perform both transmission and reception processes. In that case, each apparatus A , B each have the same processing function unit as the opposing device.

  The device A on the transmission side includes a transfer unit 7-1, a reception unit 7-2, a retransmission control unit 7-3, and a transmission unit 7-4. The transfer unit 7-1 sends communication data received from, for example, an upstream ATM interface to the retransmission control unit 7-3 (1). The receiving unit 7-2 receives the response data (retransmission request information) from the device B on the receiving side, and sends it to the retransmission control unit 7-3 (2).

  When the response data transmitted from the receiving unit 7-2 is “OK (retransmission is not required)”, the retransmission control unit 7-3 transmits the new communication data transmitted from the transfer unit 7-1 to the transmitting unit 7−. Send to 4 (3). When the response data sent from the receiving unit 7-2 is “NG (retransmission required)”, the retransmission data is sent to the transmitting unit 7-4 (4). The transmission unit 7-4 modulates the communication data transmitted from the retransmission control unit 7-3, and transmits the modulated communication data to the receiving-side apparatus B through the wireless interface (5).

  The receiving-side apparatus B includes a receiving unit 7-5, a retransmission control unit 7-6, a transmitting unit 7-7, and a transferring unit 7-8. The reception unit 7-5 receives and demodulates communication data transmitted from the device A on the transmission side via the wireless interface, and sends it to the retransmission control unit (6). The retransmission control unit 7-5 determines the communication data sent from the receiving unit 7-5. If the communication data is normal, the retransmission control unit 7-5 passes the communication data to the transfer unit 7-8 (7). Response data “OK (no retransmission required)” is sent to 7-7 (8).

  If the communication data sent from the receiver 7-5 is abnormal, response data “NG (retransmission required)” is sent to the transmitter 7-7 (8). The transmission unit 7-7 transmits the response data sent from the retransmission control unit 7-6 to the device A on the transmission side (9). The transfer unit 7-8 transmits the communication data sent from the retransmission control unit 7-6 to a downstream, for example, IP interface (10).

The signal processing time in the series of transmission processes (1) to (5) of the transmission-side apparatus A is referred to as a transmission-side apparatus delay time, and the series of (6) to (10) of the reception-side apparatus B. The signal processing time (response processing time) in the receiving process is referred to as a receiving apparatus internal delay time. The transmission / reception processing time (transmission delay time) that combines the transmission and reception processing times is the sum of the transmission-side device delay time and the reception-side device delay time. That is,
Transmission / reception processing time (transmission delay time) = delay time in transmission side apparatus + delay time in reception side apparatus

  FIG. 8 shows an example of the transmission delay time in the conventional retransmission operation. (A) of the figure shows the reference unit of the delay time in the transmission side apparatus. (B) of the figure shows the processing time of demodulation processing and decoding processing of retransmission control information (“OK” or “NG”) in the receiving unit of the transmitting side device, and (c) shows data in the transferring unit of the transmitting side device. (D) shows the processing time of the retransmission control process in the retransmission control unit of the transmission side apparatus, and (e) shows the processing time of the encoding process and the modulation process in the transmission unit of the transmission side apparatus. Show.

  Each processing time is fixedly set based on a communication data parameter such as a data amount or a data length at the time of maximum load of communication data, and is shown by being surrounded by a square frame in FIG. When the communication data load is low, the processing should be completed in the processing time with the sand pattern. However, since each processing time is fixedly set, the blank area in the square frame is not processed. The time zone only waits for the fixed processing time to expire, and the processing capability in the apparatus is not fully utilized, resulting in waste.

  FIG. 9 shows an example of a conventional transmission / reception sequence of communication data and a mode of retransmission buffer management of the receiving side apparatus. In one data storage area of the retransmission buffer, communication data of any level from level 0 to level 3 shown in FIG. 3 is stored. The illustrated example shows an example in which five communication data (# 1 to # 5) of level 2 are stored.

  The example shown in FIG. 9 shows a transmission / reception sequence with a transmission-side apparatus delay time of 8 and a reception-side apparatus delay time of 7, and a total of 15 transmission delay times. When communication data (data 1) is transmitted from the transmission side device, response data (“OK” or “NG”) for the communication data (data 1) is transmitted from the reception side device. Is transmitted to the transmission side device after the transmission delay time 15 elapses.

  The retransmission data of the communication data (data 1) is received by the receiving side apparatus after the transmission delay time 15 has elapsed since the response data (“OK” or “NG”) is transmitted from the receiving side apparatus, and is stored in the retransmission buffer. Stored cyclically.

  As a prior art document, the following Patent Document 1 describes data stored in a holding circuit of a local station that is input from a LAN and each of the wireless stations constituting a bidirectional wireless line using a variable TDD system. Measure the total amount and notify each other station of the total amount of the measured data, and each station will receive a radio frame according to the ratio of the total amount of data measured by itself and the total amount of data notified from the partner station A variable TDD control method is disclosed in which the division ratio of the section is determined by the control means of the own station.

  Patent Document 2 below performs a process of updating a threshold of a length parameter related to a queue length as a function of a link round-trip time (RTT), a data rate (DR), or a link bit rate. A queue buffer control method is disclosed.

  Further, in Patent Document 3 below, when each packet of a plurality of channels is multiplexed into a cell, the maximum delay time for cellization corresponding to information including the number of channels to be multiplexed and the data type of each channel is disclosed. Is set at the maximum delay time for cellization, and is transmitted to the ATM cell receiving device, and is the ATM cell transmission device that is dynamically set at the maximum delay time for cellization. An ATM cell transmitting apparatus having means for notifying the ATM cell receiving apparatus of the above is disclosed.

Patent Document 4 below is a control device that controls a wireless communication system having wireless communication modules of different wireless communication systems, and controls transmission / reception timing based on the communication state in each wireless communication system. A control apparatus for a wireless communication system that generates a transmission / reception timing control signal and performs transmission / reception control in each wireless communication system based on the transmission / reception timing control signal is disclosed.
JP 2007-49450 (paragraph 0025, etc.) JP-A-2004-532566 (paragraph 0026, etc.) JP 2000-49807 A (Claim 1 etc.) JP-A-2005-45330 (Claim 1 etc.)

  In a conventional communication system, the transmission / reception processing time (transmission delay time) of communication data is fixedly set based on the data amount or the data length at the time of maximum load of communication data. For this reason, even if the signal processing ends when the amount of data is small or the data length is short, the next signal processing is performed after the transmission / reception processing time (transmission delay time) at the time of maximum data elapses. The capacity was not utilized effectively, and the actual throughput was low accordingly.

  The disclosed system performs communication processing while dynamically changing communication data transmission / reception processing time (in-device delay time), thereby speeding up communication data transmission / reception processing and improving throughput. A communication system is provided.

  The data communication retransmission control method in the communication system recognizes a communication data parameter indicating a data processing characteristic such as a data amount or a data length of communication data in the transmission side apparatus, and in the transmission side apparatus according to the communication data parameter. A step of dynamically calculating a transmission processing time, performing a transmission process of the communication data within the transmission processing time and transmitting the communication data to the reception side device; and a communication data parameter indicating a data processing characteristic of the communication data in the reception side device Recognizing and dynamically calculating the reception processing time in the reception side device according to the communication data parameter, performing the reception processing of the communication data within the reception processing time, and returning the response data to the transmission side device Including the steps of:

  Further, the transmission / reception device includes a transmission processing time calculation unit that dynamically calculates a transmission processing time of communication data according to the communication data parameter, and the transmission processing time calculated by the transmission processing time calculation unit, And a retransmission control means for performing communication data transmission processing and transmitting the communication data to the receiving side device.

  Further, the transmission / reception device includes: a reception processing time calculation unit that dynamically calculates a reception processing time of communication data according to the communication data parameter; and within the reception processing time calculated by the reception processing time calculation unit, And a retransmission control unit that performs communication data reception processing and transmits response data of the communication data to the transmission side device.

  According to the data communication retransmission control described above, communication data can be transmitted with a delay of only the time necessary for the transmission or reception processing of the communication data during normal operation (when the load is below the maximum load). The transmission / reception process is increased in speed, the effective data throughput is improved, and the actual throughput can be improved.

  In addition, there is no invalid processing waiting time that occurs when a fixed transmission / reception processing time (transmission delay time) is set, and the processing capability (performance) of the device can be used effectively. Since the channel for transmission and reception can be released in a short time, transmission resources such as radio resources between the transmission and reception apparatuses can be effectively used.

  A configuration example and an operation example of communication processing in a wireless interface between transmission and reception apparatuses according to the present embodiment will be described with reference to FIGS. FIG. 1 shows a functional unit having a configuration related to retransmission control of a transmission / reception apparatus. In the figure, the transmission side device 1-10 includes a transfer unit 7-1, a reception unit 7-2, a transmission side intra-device delay time calculation unit 1-11, a retransmission control unit 1-12, and a transmission unit 7-4. Is provided. The transfer unit 7-1, the reception unit 7-2, and the transmission unit 7-4 have the same functions as those described with reference to FIG.

  The transmission-side in-device delay time calculation unit 1-11 recognizes the data amount, data length, and data type of the communication data output from the transfer unit 7-1 and determines the modulation method and the like set in the device. Parameters are acquired, and parameters such as a demodulation method of response data obtained from the receiving unit 7-2 are input.

  The transmission-side device delay time calculation unit 1-11 transmits the transmission processing time (transmission delay time) in the transmission-side device 1-10 according to the communication data parameter indicating the data processing characteristics related to the processing time required for the communication data. ) Dynamically. The retransmission control unit 1-12 is notified of the calculated transmission processing time (transmission delay time).

  The retransmission control unit 1-12 performs communication data signal processing within the transmission processing time (transmission delay time) notified from the transmission-side in-device delay time calculation unit 1-11, and transmits the communication data. At this time, the data in the retransmission control buffer is based on the reception processing time (reception delay time) notified from the reception side device 1-20 and the transmission processing time (transmission delay time) calculated by the transmission side device 1-10. The storage area is specified. If the response data is “NG (retransmission required)”, the communication data read from the data storage area is notified. If the response data is “OK (retransmission is not required)”, the transfer unit 7-1 notifies. Performs signal processing of the communication data and transmits it. The transmission data is saved in the data storage area to prepare for the next retransmission control. When transmitting communication data, the transmission processing time (transmission delay time) is transmitted in the control information storage area of the communication data frame, and the transmission processing time (transmission delay time) is transmitted to the receiving side apparatus.

  The reception side device 1-20 includes a reception unit 7-5, a reception side in-device delay time calculation unit 1-21, a retransmission control unit 1-22, a transmission unit 7-7, and a transfer unit 7-8. The reception unit 7-5, the transmission unit 7-7, and the transfer unit 7-8 have the same functions as those described with reference to FIG.

  The reception side in-device delay time calculation unit 1-21 recognizes the demodulation method of the communication data received by the reception unit 7-5, acquires parameters such as the modulation method set in the device, and The reception processing time (reception delay time) in the reception side apparatus 1-20 is dynamically calculated according to the communication data parameter indicating the data processing characteristics related to the required processing time of the communication data. The retransmission control unit 1-22 is notified of the calculated reception processing time (reception delay time).

  The retransmission control unit 1-22 performs response data generation signal processing within the reception processing time (reception delay time) notified from the reception-side in-device delay time calculation unit 1-21, and transmits the response data to the transmission-side device 1 Reply to -10. At this time, based on the transmission processing time (transmission delay time) notified from the transmission side device 1-10 and the reception processing time (reception delay time) calculated by the reception side device 1-20, data in the retransmission control buffer Signal processing such as response data generation, OK data transfer unit 7-8 notification, etc., based on the previous received data read from the data storage region and the received data notified from the receiving unit 7-5 I do. The data generated here is stored in the data storage area and prepared for the next retransmission control. Further, when reply data is returned, the reception processing time (reception delay time) is transmitted in the control information storage area of the communication data frame, and the reception processing time (reception delay time) is transmitted to the transmission side device.

  FIG. 2 shows a sequence example of a retransmission operation that is processed in the dynamic transmission / reception processing time (transmission delay time). This figure shows an example of a retransmission operation when transmission processing is performed by changing the transmission processing time (transmission delay time) in a case where the amount of communication data is small.

  (A) of the figure shows the reference unit of the delay time in the transmission side apparatus, (b) shows the processing time of the demodulation process and the decoding process of the control information in the reception unit of the transmission side apparatus, and (c) shows the transmission side. (D) shows the processing time of the retransmission control process in the retransmission control unit of the transmission side device, (e) shows the encoding process in the transmission unit of the transmission side device, The processing time of the modulation process is shown.

  Each of the above processing times is set by dynamically calculating a necessary minimum value based on a communication data parameter value such as a data amount or a data length of the communication data. In FIG. 2, each processing time is enclosed by a square frame. As is clear from comparison with FIG. 8, immediately after each process is completed, the process immediately shifts to the next process, so that an invalid process standby time does not occur and the processing load (data amount or data length, etc.) of communication data is small. In this case, the entire transmission processing time (transmission delay time) is reduced, the transmission processing speed can be increased, and the throughput of communication data can be improved.

FIG. 3 shows an example of communication data that is a source of calculation of transmission / reception processing time (transmission delay time). In transmitting side apparatus, the data _{# 1 L3} Level 3 received from the upstream or downstream, data _{# 2 L3,} the data _{# 3 L3} ~ data _{#N L3,} so that it can communicate wirelessly interface, level 2, level 1 and level Modulate to 0 data and transmit. On the receiving side, the level 0 data received by the wireless interface is demodulated into level 3 data and sent upstream or downstream.

  The time required for conversion from level 3 to level 0 is the delay time in the transmitting apparatus, and the time required for returning the response data (CRC determination result) after converting from level 0 to level 2 is the delay in the receiving apparatus. It's time. Below, an example of a calculation formula for calculating the transmission side in-device delay time (transmission side RTT) using the communication data parameter in the figure is shown. The calculation formula for the delay time in the reception side apparatus (reception side RTT) is also basically expressed by the same formula and is adjusted by the coefficients a1 to a11.

Transmission side RTT = RTTmax− (a1 / Ldata + a2 / Ndata + a3 / Lblk + a4 / Nblk + a5 / Krm + a6 / Kcode + a7 / Kpunc + a8 / Ksf + a9 / Lcode + a10 / Ncode + a11 / Kmod)
Here, Ldata is the data length, Ndata is the number of data, Lblk is the block length, Nblk is the number of blocks, Krm is the retransmission management method, Kcod is the coding rate, Kpunc is the puncture pattern, Ksf is the spreading factor, and Lcode is the code block length. , Ncode is the number of code blocks, Kmod is a modulation scheme, and a1 to a11 are delay time reduction coefficients for each parameter.

  FIG. 4 shows an example of a frame format for notifying the partner apparatus of the transmission / reception processing time (transmission delay time). (A) of the figure shows a format configuration example of a communication data frame transmitted and received by a conventional wireless interface, and (b) of FIG. 6 shows a format configuration example of a communication data frame transmitted and received by the wireless interface according to the present embodiment. Show.

  In this figure, the transmission destination ID is identification information for identifying the transmission destination device, the data number is a serial number assigned to each level 0 data, the data type is a data type classified by transmission priority, and the number of valid data is data The number of data included in the part, data # is data such as packet data, and CRC is a cyclic error correction code check result for the number of data.

  In the present embodiment, areas of the transmission side RTT and the reception side RTT are provided in the above format configuration, and transmission processing time (transmission delay time) in communication data transmission from the transmission side apparatus to the reception side apparatus is provided in the area of the transmission side RTT. And the information on the reception processing time (reception delay time) in the response data response from the reception side apparatus to the transmission side apparatus is stored in the area of the reception side RTT.

  FIG. 5 shows an example of a communication data transmission / reception sequence in the dynamic transmission / reception processing time (transmission delay time) according to this embodiment. The example shown in FIG. 5 shows a transmission / reception sequence in which the maximum value of the delay time in the transmission side apparatus is 8, the maximum value of the delay time in the reception side apparatus is 7, and a maximum of 15 transmission delay times are included.

  Assuming that the transmission side device delay time requires a maximum value of 8 and the reception side device delay time of a maximum value of 7, the communication data of data 1 to data 3 is transmitted from the transmission side device to the communication data (data 1 to data 3), the response data (“OK” or “NG”) for the communication data (data 1 to data 3) is transmitted from the receiving side device after the transmission of the communication data (data 1). Is received by the transmission side device after elapse of time.

  On the other hand, the data 4 is received in a short time as shown by the one-dot chain line in FIG. It is received by the side device and stored in the retransmission buffer of the reception side device. Compared to the conventional transmission by the delay time in the transmission side apparatus indicated by the dotted line, since the data is stored in the retransmission buffer of the reception side apparatus in a short time, the decoding process is performed after all of the plurality of communication data are gathered. The receiving side apparatus can perform the decoding process promptly, and can improve the throughput.

  FIG. 6 shows an example of a retransmission buffer management mode of the receiving side apparatus. In the figure, (a) is the reception processing time (reception side RTT) calculated by the reception side device, (b) is the transmission processing time (transmission side RTT) notified from the transmission side device, and (c) is the reception processing time. (Reception side RTT) and transmission processing time (transmission side RTT) plus transmission delay time (total RTT), (d) shows retransmission buffer, and (e) shows the value of the reception counter for each buffer point of the retransmission buffer. ing.

  As a retransmission buffer management technique, a reception counter that counts reception data for each buffer may be provided, and a technique in which the timing when the reception counter = total RTT + 1 is determined as the retransmission data reception timing (sand pattern portion in FIG. 6) can be used. . Then, based on the buffer point where the reception data is stored and the value of the reception counter, the buffer point where the retransmission data is stored can be specified.

  In the illustrated example, for data 1 to data 3, the reception side RTT is 7 and the transmission side RTT is 8, the total RTT is 15, and the reception timing of the retransmission data is 15 + 1 = 16 for each buffer. Based on the buffer points of data 1 to data 3 and the value 16 of the reception counter, the retransmission data storage buffer point is specified.

  For data 4, the reception side RTT is 6 and the transmission side RTT is 6, the total RTT is 12, and the reception timing of the retransmission data is the timing when the reception counter for each buffer becomes 12 + 1 = 13. Yes, based on the buffer point of data 4 and the value 13 of the reception counter, the storage buffer point of retransmission data is specified.

It is a figure which shows the function part which concerns on the retransmission control of a transmission / reception apparatus. It is a figure which shows the example of a sequence of the resending operation | movement processed by dynamic processing time. It is a figure which shows the example of the communication data used as the origin of calculation of dynamic processing time. It is a figure which shows an example of the data format which notifies transmission / reception processing time (transmission delay time) to the other party apparatus. It is a figure which shows an example of the transmission / reception sequence of the communication data in dynamic processing time. It is a figure which shows an example of the aspect of the retransmission buffer management of a receiving side apparatus. It is a figure which shows the function part which concerns on the retransmission control of the conventional transmission / reception apparatus. It is a figure which shows the sequence of the resending operation | movement processed in the conventional fixed processing time. It is a figure which shows the aspect of the transmission / reception sequence in the conventional fixed transmission / reception processing time, and retransmission buffer management.

Explanation of symbols

1-10 Transmission Side Device 1-11 Transmission Side Device Delay Time Calculation Unit 1-12 Retransmission Control Unit of Transmission Side Device 1-20 Reception Side Device 1-21 Reception Side Device Delay Time Calculation Unit 1-22 Reception Side Device 7-1 Retransmission control unit 7-1 Transmission unit of transmission side device 7-2 Reception unit of transmission side device 7-4 Transmission unit of transmission side device 7-5 Reception unit of reception side device 7-7 Transmission unit of reception side device 7 -8 Transfer unit of receiving device

Claims (5)

The transmission side device recognizes a communication data parameter indicating the data processing characteristics of the communication data, dynamically calculates a transmission processing time in the transmission side device according to the communication data parameter, and the communication is performed within the transmission processing time. Performing data transmission processing and transmitting to the receiving side device;
Receiving the communication data parameter indicating the data processing characteristics of the communication data in the receiving side device, dynamically calculating the reception processing time in the receiving side device according to the communication data parameter, and the communication within the reception processing time Performing a data reception process and returning response data to the transmitting device;
A data communication retransmission control method including:   The transmission side device notifies the reception side device of the transmission processing time when transmitting communication data to the reception side device, and the reception side device calculates the notified transmission processing time and the calculated reception processing time. The data communication retransmission control method according to claim 1, wherein a reception timing of retransmission data is specified on the receiving side device.   When the reception side device returns response data to the transmission side device, the reception side device notifies the transmission side device of the reception processing time, and the transmission side device calculates the notified reception processing time and the calculated transmission processing time. The data communication retransmission control method according to claim 1, wherein the reception timing of response data in the transmission side device is specified based on the transmission data. A transmission processing time calculating means for recognizing a communication data parameter indicating data processing characteristics of the communication data and dynamically calculating a transmission processing time of the communication data according to the communication data parameter;
Retransmission control means for performing transmission processing of the communication data and transmitting to the receiving side device within the transmission processing time calculated by the transmission processing time calculation means;
A transmission / reception device comprising: A reception processing time calculating means for recognizing a communication data parameter indicating data processing characteristics of the communication data and dynamically calculating a reception processing time of the communication data according to the communication data parameter;
Retransmission control means for performing reception processing of the communication data within the reception processing time calculated by the reception processing time calculation means, and transmitting response data of the communication data to the transmission side device;
A transmission / reception device comprising:

Images