JP5230665B2 - Data receiving apparatus and data receiving method - Google Patents

Description

  The present invention relates to a data reception apparatus and a data reception method, and more particularly to suitable control of a reception buffer size for each of a plurality of channels.

  In recent years, with the spread of the Internet, networking has rapidly progressed, and devices that perform a plurality of LAN (Local Area Network) transmission controls have been developed. In the LAN transmission control device, a buffer is conventionally provided for temporarily storing signal transmission / reception data. Here, for the purpose of reducing the cost, the storage capacity of the buffer should be as small as possible.

  On the other hand, when the storage capacity of the buffer is smaller than the capacity of the received data, that is, the received packet, the received data cannot be received, a retransmission request is generated, and the system performance is degraded. That is, in the buffer size, the cost and the system performance are in a trade-off relationship, and it is required to improve the system performance while suppressing the cost.

  Therefore, a method of dynamically managing the storage capacity of the buffer by dividing it into a storage area for transmission data and a storage area for reception data has been proposed (for example, see Patent Document 1). Also, a method has been proposed in which a storage area for transmission data and a storage area for reception data are used in common (see, for example, Patent Document 2).

JP-A-11-196097 JP 2009-10835 A

  However, in the conventional LAN transmission control device, the device as in Patent Document 1 changes the buffer size every time transmission / reception processing occurs, and returns the buffer size to the original capacity after the processing is completed. When the channels are controlled simultaneously, there is a problem that the processing load increases and the throughput decreases.

  Further, in the apparatus as disclosed in Patent Document 2, since the transmission / reception transmission buffer is switched and used, LAN data cannot be transmitted while the transmission buffer is used for reception. For this reason, when transmitting a signal for real-time control, there is a problem that transmission / reception control with guaranteed time criticality cannot be performed.

  The present invention has been made to solve the above-described problems of throughput reduction and time criticality, and is a data receiving apparatus capable of controlling a retransmission rate for each channel of a plurality of LAN channels with a limited buffer size. The purpose is to provide.

  In order to solve the above-described problem, an aspect of the present invention is a data receiving device that receives data input from a plurality of channels via a network by storing the data in a buffer area provided for each of the plurality of channels. A request retransmission rate storage unit that stores, for each of the plurality of channels, a requested retransmission rate that is information on a retransmission rate requested by another device that transmits data to the channel; Based on the data size storage unit that stores a predetermined number of data sizes of data to be transmitted to the channel for each of the plurality of channels, and for each of the plurality of channels based on the stored information on the predetermined number of data sizes. And a buffer size determining unit that determines the size of the buffer area so as to satisfy the stored request retransmission rate.

  Here, the buffer size determination unit determines a threshold for the stored predetermined number of data sizes as a temporary buffer size, and a calculated retransmission rate that is a ratio of the number of values exceeding the threshold in the predetermined number of data sizes It is preferable that the size of the buffer area is determined by setting the threshold value so as to satisfy the requested retransmission rate.

  Further, the buffer size determining unit obtains the calculated retransmission rate while gradually increasing the determined threshold value, and determines the maximum threshold value at which the calculated retransmission rate is equal to or less than the requested retransmission rate as the size of the buffer area. It is preferable to do.

  In addition, the buffer size determination unit, when the total size of the buffer area determined for the plurality of channels exceeds the upper limit of the available storage area, each based on the stored request retransmission rate The size of the buffer area of the channel is adjusted.

  In addition, the buffer size determination unit preferentially selects a channel with a low request retransmission rate when the total size of the buffer areas determined for the plurality of channels exceeds an upper limit of an available storage area. A size of the determined buffer area is allocated.

  And a data reception processing unit that receives the data input to the channel by storing the data in the buffer area, wherein the data reception processing unit is configured such that a size of the data input to the channel is a buffer of the channel. If the value exceeds the value determined as the size of the area, the value determined as the size of the buffer area of the other channel is reduced to determine the size of the buffer area of the channel to which the data is input. And a retransmission request is made to the transmission source of the input data.

  In addition, when the size of the data input to the channel exceeds the value determined as the size of the buffer area of the channel, the data reception processing unit sets the shortage size to the number of the other channels. Is reduced to a value determined as the size of the buffer area of the channel to which the data is input. It is characterized by adding.

  In addition, when the size of data input to the channel exceeds the value determined as the size of the buffer area of the channel, the data reception processing unit responds to the requested retransmission rate of the other channel. It is preferable to increase the value determined as the size of the buffer area of the channel to which the data is input by decreasing the value determined as the size of the buffer area of the channel.

Further, when the size of the data input to the channel exceeds the value determined as the size of the buffer area of the channel, the shortage size is B, the total number of the plurality of channels is N, If the value to be reduced from the size of the buffer area of channel i is Di and the requested retransmission rate of channel i is Ri, it is preferable to satisfy the relationship of the following equation (4).

  According to another aspect of the present invention, there is provided a data receiving method for receiving data input from a plurality of channels via a network by storing the data in a buffer area provided for each of the plurality of channels. Data of a request retransmission rate, which is information on a retransmission rate requested by another device that transmits data to a channel, is stored for each of the plurality of channels, and data of data that the other device transmits to the channel A predetermined number of size information is stored for each of the plurality of channels, and the buffer area is configured to satisfy the stored request retransmission rate for each of the plurality of channels based on the stored information on the predetermined number of data sizes. It is characterized by determining the size.

  By employing the technique of the present invention, it is possible to provide a data receiving apparatus capable of controlling the retransmission rate for each of a plurality of LAN channels with a limited buffer size.

1 is a block diagram illustrating a data transmission / reception system including a data reception device according to an embodiment of the present invention. It is a figure which shows the hardware constitutions of the control apparatus which concerns on embodiment of this invention. It is a figure which shows the example of the information memorize | stored in the request | requirement resending rate storage part which concerns on embodiment of this invention. It is a figure which shows the example of the information memorize | stored in the buffer size storage part 13 which concerns on embodiment of this invention. It is a flowchart which shows the sample collection process of the reception data size which concerns on embodiment of this invention. It is a figure which shows the information of the sample of the reception data size which concerns on embodiment of this invention. It is a flowchart which shows the buffer size calculation process which concerns on embodiment of this invention. It is a flowchart which shows the reception process at the time of the data overflow which concerns on embodiment of this invention.

Hereinafter, specific embodiments of the present invention will be described in detail with reference to the drawings.
In the present embodiment, a data transmission control method in a system including a plurality of monitoring devices and a control device that receives information such as detection signals from each monitoring device and performs control according to the received information will be described as an example. To do. In such a system, data is constantly transmitted and time criticality is required for transmitted / received data. By using the data transmission control method according to the present embodiment, the data receiving unit on the control device side in such a system can control the retransmission rate for each channel of a plurality of LAN channels within a limited buffer size. it can.

  FIG. 1 is a block diagram illustrating a configuration of a data receiving unit in a control device 10 that receives information transmitted from a plurality of monitoring devices 21 and 22 and each monitoring device and performs various controls in the system according to the present embodiment. It is. As shown in FIG. 1, the control device 10 according to this embodiment includes a reception buffer control unit 1, a reception buffer 2, LAN reception units 3 a, 3 b,... 3 n (hereinafter collectively referred to as a LAN reception unit 3), Buses 4a and 4b are included.

  Further, the reception buffer control unit 1 includes a request retransmission rate storage unit 11, a reception buffer size calculation unit 12, a reception buffer size storage unit 13, and a data reception processing unit 14. The reception buffer 2 includes a buffer area 2a, a buffer area 2b,... A buffer area 2n. A channel is constituted by a combination of the LAN receivers 3a, 3b,... 3n and the buffer areas 2a, 2b,. For example, the received data input to the LAN receiver 3a is received by being temporarily stored in the buffer area 2a.

  The reception buffer control unit 1 is a device that controls the reception buffer 2, and functions as a data reception device that receives data in the control device 10. The reception buffer 2 is a storage area for temporarily storing reception data. The LAN receiver 3 is an interface through which received data is input from the outside. As shown in FIG. 1, a plurality of LAN receivers 3 are provided such as LAN receivers 3a, 3b,... 3n, each corresponding to each channel. Each LAN receiver 3 is connected to the monitoring devices 21 and 22 via a network line such as the Internet. The buses 4a and 4b are transmission paths for transmitting signals exchanged between the LAN receiving unit 3 and the receiving buffer control unit 1 or between the receiving buffer control unit 1 and the receiving buffer 2.

  In the reception buffer control unit 1, the retransmission request rate storage unit 11 stores information on the retransmission rate requested by the monitoring devices 21 and 22 to be connected (hereinafter referred to as requested retransmission rate information) for each channel. It is a retransmission request rate storage unit that is stored. The requested retransmission rate information is a ratio of the number of retransmission request data to the total number of received data as a retransmission rate allowable for each channel in order to obtain a suitable throughput for data reception in the control apparatus 10, and is connected to each channel. It depends on the monitoring device. Details will be described later.

  The reception buffer size calculation unit 12 is based on the requested retransmission rate information stored in the requested retransmission rate storage unit 11, and the buffer size of each channel to satisfy the requested retransmission rate, that is, the buffer areas 2a, 2b,. The storage capacity of the reception buffer 2 assigned to 2n is calculated and determined. That is, the reception buffer size calculation unit 12 functions as a buffer size determination unit. The function of the reception buffer size calculation unit 12 is one of the gist according to the present embodiment. Details will be described later.

  The reception buffer size storage unit 13 is a storage unit that stores information on the buffer size of each channel calculated by the reception buffer size calculation unit 12. The data reception processing unit 14 converts the reception data input to the LAN reception unit 3 into buffer areas 2a, 2b,... 2n based on the information stored in the reception buffer size storage unit 13 and the input channel. The data is received by holding it in the corresponding area.

  Further, the data reception processing unit 14 sets the capacity of the buffer areas 2a, 2b,... 2n in the reception buffer 2 based on the information stored in the reception buffer size storage unit 13, and the data transmission / reception status It can be arbitrarily changed according to the above.

  As shown in FIG. 1, the monitoring device 21 includes LAN transmission units 21a and 21b, and the monitoring device 22 includes a LAN transmission unit 22n. The LAN transmitter 21a is connected to the LAN receiver 3a, the LAN transmitter 22a is connected to the LAN receiver 3b, and the LAN transmitter 22n is connected to the LAN receiver 3n via a public line such as the Internet or a dedicated line.

  In FIG. 1, for the sake of convenience, each LAN transmission unit and LAN reception unit are shown to be connected one-to-one. However, as described above, both are public such as the Internet. They are connected to lines and dedicated lines and are physically connected to each other. That is, the information transmission destinations of the LAN transmission units 21a, 21b, and 22n are set to the LAN reception units 3a, 3b, and 3n, respectively, thereby realizing a one-to-one connection relationship as shown in FIG. Has been.

  Next, a hardware configuration of the control device 10 according to the present embodiment will be described. FIG. 2 is a diagram illustrating an example of a hardware configuration according to the present embodiment. As shown in FIG. 2, the control device according to the present embodiment includes the same configuration as that of a general server or PC. That is, the information processing terminal according to the present embodiment includes a CPU (Central Processing Unit) 101, an FPGA (Field Programmable Gate Array) 102, a RAM (Random Access Memory) 103, a ROM (Read Only Memory) 104, and an HDD (Hard Read Memory). ) 105 and the LAN receiver 3. As shown in FIG. 2, the ROM 104, the HDD 105, the LAN receiver 3 and the FPGA 102 are connected by a bus 4a, and the FPGA 102 and the RAM 103 are connected by a bus 4b.

  The CPU 101 is a calculation means and controls the operation of the entire control device. In this embodiment, the FPGA 102 is a circuit that performs information transmission between the CPU 101, the RAM 103, and the bus 4b, and also functions as a controller of the RAM 103. That is, the reception buffer control unit 1 described in FIG. 1 is realized by the FPGA 102. The RAM 103 is a volatile storage medium capable of reading and writing information at high speed. The RAM 103 functions as the reception buffer 2 described with reference to FIG. 1 and is used as a work area when the CPU 101 processes information.

  The ROM 104 is a read-only nonvolatile storage medium and stores a program such as firmware. The HDD 105 is a non-volatile storage medium that can read and write information, and stores an OS (Operating System), various control programs, application programs, and the like. The LAN receiver 3 corresponds to the LAN receivers 3a, 3b,... 3n described in FIG. In the present embodiment, the average throughput of received data exchanged via the bus 4a is lower than the throughput of the bus 4b.

  In such a hardware configuration, a program stored in a storage medium such as the ROM 104, the HDD 105, or an optical disk (not shown) is read into the RAM 103, and operates according to the control of the CPU 101, thereby configuring a software control unit. A functional block that controls the control device according to the present embodiment is configured by a combination of the software control unit configured as described above and hardware such as the FPGA 102.

  Next, information stored in the requested retransmission rate storage unit 11 will be described with reference to FIG. FIG. 3 is a diagram illustrating an example of information stored in the request retransmission rate storage unit 11 according to the present embodiment. As shown in FIG. 3, the requested retransmission rate storage unit 11 stores information on a table indicating the retransmission rate required for each of the LAN receivers 3a, 3b,. For example, in the case of LAN reception 3a, the retransmission rate is required to be 10% or less.

  This retransmission rate is typically determined by the type of data transmitted by the monitoring devices 21 and 22 and the LAN transmission units 21a, 21b,. In other words, depending on what is monitored by the monitoring device 20, there is a variety from those in which a delay is not allowed and real-time characteristics are strongly required, to those in which a certain amount of delay is not a problem. Therefore, as shown in FIG. 3, the required retransmission rate differs depending on the LAN transmission unit of the monitoring device 20 connected to each of the LAM reception units 3. In the present embodiment, by effectively determining the size of each buffer area 2a, 2b,... 2n according to the requested retransmission rate, effective use of the buffer area with a limited size is realized.

  Next, information stored in the reception buffer size storage unit 13 will be described with reference to FIG. FIG. 4 is a diagram illustrating an example of information stored in the reception buffer size storage unit 13 according to the present embodiment. As shown in FIG. 4, the reception buffer size storage unit 13 stores table information indicating the capacities of the buffer areas 2a, 2b,. For example, in the case of the buffer area 2a, the storage capacity is Buffer2a (bytes).

  Next, in the control device 10 according to the present embodiment, the operation until the reception buffer size calculation unit 12 calculates the buffer size of the buffer area of each channel and stores it in the reception buffer size storage unit 13 will be described. The operation of the reception buffer size calculation unit 12 according to this embodiment is roughly divided into a reception data size sample collection process and a buffer size calculation process. FIG. 5 is a flowchart showing a received data size sample collection process in the operation of the receive buffer size calculator 12 according to the present embodiment.

  When executing the operation shown in FIG. 5, since the buffer sizes of the buffer areas 2a, 2b,... 2n in the reception buffer 2 have not yet been calculated, the reception buffer size storage unit 13 includes the buffer areas 2a, A table indicating values arbitrarily determined as buffer sizes 2b,..., 2n is stored.

  As shown in FIG. 5, the reception buffer size calculation unit 12 first sets the variable “k” to “0” (S501). When data is input to the LAN receiver 3 and data is received by the data reception processor 14 (S502), the reception buffer size calculator 12 increments the variable “k” (S503). In the present embodiment, the unit of received data received in S502 and counted in S503 is one packet.

  After the processing of S503, the reception buffer size calculation unit 12 stores the size of the reception data received in S502 as a sample (S504). In S502, it is not always necessary to complete reception of data by the reception processing unit 14, and it is sufficient that the size of the received data can be stored as a sample in S504. Therefore, in S502, it is possible to proceed by simply inputting data to the LAN receiver 3. Thereafter, the reception buffer size calculation unit 12 repeats the processing from S502 until the value of the variable “k” reaches a predetermined number of samples (S505 / NO). Then, when the value of the variable “k” reaches a predetermined number of samples (S505 / YES), the reception buffer size calculation unit 12 ends the process. The process of FIG. 5 is preferably operated periodically, but there is also a method that is performed only once when the apparatus is started in order to reduce the processing load.

  The reception buffer size calculation unit 12 performs the process shown in FIG. 5 for all channels. That is, for all channels, samples having the same number of reception data sizes as the predetermined number of samples are collected. The information of the received data size samples collected in this way is stored for each channel as shown in FIG. That is, the reception buffer size calculation unit 12 functions as a data size storage unit. Based on the received data size sample stored in this way, a buffer size calculation process is executed.

  FIG. 7 is a flowchart showing buffer size calculation processing in the operation of the reception buffer size calculation unit 12 according to the present embodiment. As a premise of the processing of FIG. 7, the processing shown in FIG. 5 is executed and the sample data of the received data size is stored as shown in FIG. 6, and the requested retransmission rate of each channel is as described in FIG. Is stored in the request retransmission rate storage unit 11.

  In the operation shown in FIG. 7, the variable “A” (bytes) as the size of the buffer area to be calculated, the number of samples of the received data size collected for each channel in FIG. 5, that is, the predetermined sample in FIG. "M" (number) as the number, variable "S" (%) as the requested retransmission rate of the channel whose buffer size is to be calculated, and counted when the sample value of the received data size is smaller than the value of the variable "A" The size undercounter “M1” that is a variable to be increased, the size overcounter “M2” that is a variable to be counted up when it is large, the variable “n” that indicates the number of the sample being analyzed, and obtained by calculation The variable “Q” is used as the measurement retransmission rate.

  As shown in FIG. 7, the reception buffer size calculation unit 12 first sets the variable “A” to “1” (bytes) (S701). Further, the reception buffer size calculation unit 12 sets the variables “n”, “M1”, and “M2” to “0” (S702). Then, as shown in FIG. 6, the stored sample values are sequentially read out as analysis targets (S703), and the variable “n” is incremented (S704). When the sample value is read, the reception buffer size calculation unit 12 compares the sample value being analyzed with the value of the variable “A” (S705).

  If the sample value being analyzed is equal to or smaller than the value of the variable “A” as a result of S705 (S705 / YES), that is, the value of the variable “A” is set as the buffer size to correspond to the sample value being analyzed. If the received data can be received, the reception buffer size calculation unit 12 increments the variable “M1” (S706). On the other hand, if the sample value being analyzed is larger than the variable “A” (S705 / NO), that is, if the value of the variable “A” is set as the buffer size, received data corresponding to the sample value being analyzed is received. If not, the reception buffer size calculation unit 12 increments the variable “M2” (S707).

After the processing of S706 or S707, the reception buffer size calculation unit 12 repeats the processing from S703 until the value of the variable “n” reaches the value of the variable “M” (S708 / NO). On the other hand, when the value of the variable “n” reaches the value of the variable “M” (S708 / YES), the reception buffer size calculation unit 12 calculates the measured retransmission rate “Q” (S709). Here, the measured retransmission rate “Q” (%) is obtained by the following equation (1).

  When the reception buffer size calculation unit 12 obtains the measured retransmission rate Q by the equation (1), the reception buffer size calculation unit 12 compares the Q with the requested retransmission rate “S” (S710). As a result of the comparison in S710, when the measured retransmission rate “Q” is equal to or less than the requested retransmission rate “S” (S710 / YES), that is, when the requested retransmission rate is satisfied with the current value “A”, the reception buffer size The calculation unit 12 formally determines the value of “A” at that time as the size of the buffer area of the channel (S711), and ends the process. That is, the variable “A” is used as a temporary buffer size in the processing of FIG.

  On the other hand, when the measured retransmission rate “Q” is larger than the requested retransmission rate “S” (S710 / NO), that is, when the requested retransmission rate is not satisfied with the current value “A”, the reception buffer size calculating unit 12 The value of “A” is incremented by “1” (byte) (S712), and the processing from S702 is repeated. With such processing, the buffer size calculation processing according to the present embodiment is completed. Similar to the process of FIG. 5, the reception buffer size calculator 12 executes the process of FIG. 7 for all channels. As a result, as described in FIG. 4, the sizes of the buffer areas 2a, 2b,... 2n of each channel are determined, and information is stored in the reception buffer size storage unit 13.

  As a result of executing the processing shown in FIG. 7, if the sum of the values calculated as the buffer size of each channel is within the upper limit value of the size that can be used as the storage capacity of the reception buffer 2, the calculation result is used as it is in the buffer area. What is necessary is just to use as a size of 2a, 2b, ... 2n. On the other hand, the sum of the values calculated as the buffer size of each channel may exceed the upper limit of the size that can be used as the storage capacity of the reception buffer 2. In this case, for example, it is preferable to allocate a buffer size preferentially calculated from a channel with a small request retransmission rate, that is, a buffer size that satisfies the request retransmission rate.

  This is because the low request retransmission rate means that the number of received data is large, and the overall system throughput can be improved by preferentially allocating buffers to such channels. is there. In addition, the priority for allocating the buffer size may be determined based on the priority for each channel set by the user instead of the requested retransmission rate.

  In this way, the retransmission rate at an arbitrary buffer size is calculated based on a predetermined number of sample values, and the size of the buffer area is determined so that the retransmission rate requested by the communication target device is satisfied for each channel. This makes it possible to control the retransmission rate for each of a plurality of LAN channels with a limited buffer size.

  The present invention can be applied to a monitoring control system including the monitoring devices 21 and 22 and the control device 10 as described in FIG. 1, and maintains a constant throughput characteristic and time criticality by controlling a retransmission rate of received data for each channel. The data to be transmitted can be transmitted. Next, the operation of the present invention when LAN data larger than the reception buffer size satisfying the requested retransmission rate determined by the above method is received and the reception buffer overflows will be described.

  FIG. 8 is a flowchart showing a reception processing procedure when reception data overflows according to the present invention. When reception data is input to the LAN receiver 3, the data reception processing unit 14 checks the size of the reception data in the reception buffer control unit 1 (S801), and information stored in the reception buffer size storage unit 13 is stored. Referring to FIG. 4, the size of the buffer area of the channel to which data is input is compared with the size of the received data (S802).

  If the size of the received data is equal to or smaller than the size of the buffer area as a result of the comparison in S802 (S802 / YES), the data reception processing unit 14 uses the received data input to the LAN receiving unit 3 as the buffer area of the corresponding channel. (S803), and the process ends. On the other hand, when the size of the received data is larger than the size of the buffer area (S802 / NO), the data reception processing unit 14 reduces the size of the buffer area of the other channel to enable reception of the input data. (S804), the size of the buffer area of the channel to which data is input is increased (S805). Then, a data retransmission request is transmitted to the transmission source of the received data input in S801 (S806), and the process ends.

Here, an example of a method for adjusting the size of the reception buffer of another channel in S804 will be described below. Assuming that the shortage of the reception buffer size is “B” (bytes), the number of channels is “N” (number), and the buffer size to be reduced in other channels is “C” (bytes), this “C” is expressed by the following equation: Calculated in (2).

  That is, when a capacity is allocated from another channel to the reception buffer of the channel in which the reception data overflows, the size allocated from each other channel is “B / (N−1)” (bytes).

Further, as in the example of Expression (2), the allocation amount can be determined in consideration of the retransmission request rate of each channel, instead of allocating the size equally from other channels. In this case, assuming that the adjustment size of the reception buffer of channel “i” is “Di” (bytes) and the requested retransmission rate is “Ri”, this “Di” is obtained by the following equation (3).

  By applying “Di” obtained by the equation (3) as the capacity allocated from each of the other channels, the channel having a smaller request retransmission rate is allocated less and the channel having a higher requested retransmission rate is allocated more. In addition, all the insufficient capacity may be allocated from the buffer capacity of the channel with the largest retransmission request rate.

  In the above embodiment, the case where “1” is used as the initial value of the variable “A” in S701 of FIG. 7 and incremented by “1” in S712 has been described as an example. However, the present invention is not limited to this, and when there is a minimum size to be secured as the size of each of the buffer areas 2a, 2b,. Further, the unit for increasing the value of the variable “A” in S712 is not limited to “1”, and may be, for example, a unit of a cell of the storage medium constituting the buffer area.

1 receive buffer controller,
2 receive buffer,
2a, 2b, 2n buffer area,
3, 3a, 3b, 3n LAN receiver,
4a, 4b bus,
11 retransmission request rate storage unit,
12 Receive buffer size calculator,
13 Receive buffer size storage,
14 data reception processing unit,
101 CPU,
102 FPGA,
103 RAM,
104 ROM,
105 HDD

Claims (10)

A data receiving device for receiving data input from a plurality of channels via a network by storing the data in a buffer area provided for each of the plurality of channels,
A requested retransmission rate storage unit that stores a requested retransmission rate, which is information on a retransmission rate requested by another device that transmits data to the channel, for each of the plurality of channels;
A data size storage unit for storing a predetermined number of data sizes of data transmitted from the other device to the channel for each of the plurality of channels;
A buffer size determining unit that determines the size of the buffer area so as to satisfy the stored request retransmission rate for each of the plurality of channels based on the stored information on the predetermined number of data sizes. Data receiving device.   The buffer size determination unit determines a threshold value for the stored predetermined number of data sizes as a temporary buffer size, and a calculated retransmission rate that is a ratio of the number of values exceeding the threshold value in the predetermined number of data sizes is the request The data receiving apparatus according to claim 1, wherein the size of the buffer area is determined by setting the threshold value so as to satisfy a retransmission rate.   The buffer size determination unit obtains the calculated retransmission rate while gradually increasing the determined threshold, and determines the maximum threshold value at which the calculated retransmission rate is equal to or less than the requested retransmission rate as the size of the buffer area. The data receiving apparatus according to claim 2.   The buffer size determination unit, when the total size of the buffer areas determined for the plurality of channels exceeds an upper limit value of an available storage area, based on the stored request retransmission rate, 4. The data receiving apparatus according to claim 1, wherein the size of the buffer area is adjusted.   The buffer size determining unit is configured to preferentially determine a channel with a low request retransmission rate when a total size of the buffer areas determined for the plurality of channels exceeds an upper limit value of an available storage area. 5. The data receiving apparatus according to claim 4, wherein a size of the buffer area is allocated. A data reception processing unit for receiving the data input to the channel by storing the data in the buffer area;
When the size of the data input to the channel exceeds the value determined as the size of the buffer area of the channel, the data reception processing unit is determined as the size of the buffer area of another channel 6. The value determined as the size of the buffer area of the channel to which the data is input is increased by decreasing the value, and a retransmission request is made to the transmission source of the input data. The data receiving device according to any one of the above.   When the size of the data input to the channel exceeds the value determined as the size of the buffer area of the channel, the data reception processing unit divides the insufficient size by the number of the other channels. By subtracting the value from the value determined as the size of the buffer area of the other channel, the size of the shortage is added to the value determined as the size of the buffer area of the channel to which the data is input. The data receiving apparatus according to claim 6.   When the size of data input to the channel exceeds the value determined as the size of the buffer area of the channel, the data reception processing unit sets a value according to the requested retransmission rate of the other channel. The value determined as the size of the buffer area of the channel to which the data is input is increased by decreasing the value determined as the size of the buffer area of the channel. Data receiving device. When the size of data input to the channel exceeds the value determined as the size of the buffer area of the channel, the shortage size is B, the total number of the plurality of channels is N, and the channel i 9. The data receiving apparatus according to claim 8, wherein the following relationship is satisfied, where Di is a value to be reduced from the size of the buffer area and Ri is a requested retransmission rate of channel i.

A data receiving method for receiving data input from a plurality of channels via a network by storing the data in a buffer area provided for each of the plurality of channels,
Storing a requested retransmission rate, which is information on a retransmission rate requested by another device that transmits data to the channel, for each of the plurality of channels;
Storing a predetermined number of data size information for each of the plurality of channels, the data transmitted by the other device to the channel;
A data receiving method, comprising: determining a size of the buffer area so as to satisfy the stored request retransmission rate for each of the plurality of channels based on the stored information on a predetermined number of data sizes.

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