Data transmission apparatus, data transmission and reception system, data transmission method, and program

Abstract

To reduce the possibility of the occurrence of congestion even in such a communication form that data are unilaterally transmitted from a transmission side.SOLUTION: A data transmission device includes data transmission speed calculation means for calculating a data transmission speed on the basis of one of a communication speed of a communication line and a data amount of transmission data and information indicating a data transmission speed calculation condition, and transmission means for transmitting the transmission data at the data transmission speed through the communication line.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a data transmission device, a data transmission and reception system, a data transmission method, and a program. [Background technology]

[0002] For example, when connecting to the Internet, multiple users may share a communication line. In this case, if some users use a large amount of communication bandwidth, the communication bandwidth available to other users may become smaller, resulting in congestion. One technique for preventing such congestion is disclosed in Patent Document 1, for example.

[0003] In the technology disclosed in Patent Document 1, for example, when accessing a server to download data, the user sets an allowed access time, which is the time allowed for access, in the communication terminal from which the download is performed. When the server receives a reception request for a website from the communication terminal, it receives from the communication terminal information such as the communication speed, the allowed access time, the memory capacity and information processing speed of the communication terminal along with the reception request.

[0004] The server determines the compression rate based on the amount of image data included in the requested website, the received communication speed, the allowed access time, the memory capacity and information processing speed of the communication terminal, etc. The server then transmits the image data compressed at the determined compression rate to the communication terminal. This allows the amount of image data to be downloaded to be compressed to a size appropriate for the communication speed and the specifications of the communication terminal, making it less likely to cause congestion. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-061542 Summary of the Invention [Problem to be solved by the invention]

[0006] However, the technology disclosed in Patent Document 1 is a technology that is valid for request-response type communication between a communication terminal that requests to receive data and a server that receives the request and transmits the data. Therefore, in a communication format in which data is transmitted unilaterally from the transmitting side, even if this technology is applied, there is a problem that congestion cannot be prevented.

[0007] An object of the present disclosure is to provide a data transmission device, a data transmission and reception system, a data transmission method, and a program that solve the above-mentioned problems. [Means for solving the problem]

[0008] A data transmission device according to one aspect of the present disclosure includes a data transmission rate calculation means for calculating a data transmission rate based on either the communication rate of a communication line or the amount of data to be transmitted, and information indicating data transmission rate calculation conditions, and a transmission means for transmitting the transmission data at the data transmission rate through the communication line.

[0009] A data transmission and reception system according to one aspect of the present disclosure comprises a data transmission device and a data receiving device, wherein the data transmission device comprises a data transmission rate calculation means for calculating a data transmission rate based on either the communication speed of a communication line or the amount of data to be transmitted, and information indicating data transmission rate calculation conditions, and a transmission means for transmitting transmission data at the data transmission rate through the communication line, and the data receiving device comprises a receiving means for receiving the transmission data.

[0010] A data transmission method according to one aspect of the present disclosure calculates a data transmission speed based on either the communication speed of a communication line or the amount of data to be transmitted, and information indicating data transmission speed calculation conditions, and transmits the transmission data at the calculated data transmission speed through the communication line.

[0011] A program according to one aspect of the present disclosure is a program for causing a computer to function as a data transmission rate calculation means that calculates a data transmission rate based on either the communication rate of a communication line or the amount of data to be transmitted, and information indicating data transmission rate calculation conditions, and a transmission means that transmits the transmission data at the data transmission rate through the communication line. [Effects of the Invention]

[0012] According to the above aspect, even in a communication mode in which data is unilaterally transmitted from the transmitting side, the possibility of congestion occurring can be reduced. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a block diagram illustrating an example of a configuration of a data transmission and reception system according to the present disclosure. [Figure 2] FIG. 10 is a diagram illustrating an example of a data format of a correspondence table according to the present disclosure. [Figure 3] FIG. 10 is an example of a sequence diagram illustrating a processing flow by the data transmission system according to the present disclosure. [Figure 4] 10 is an example of a flowchart illustrating a flow of processing by a data transmission device according to the present disclosure. [Figure 5] 10 is an example of a flowchart illustrating a flow of processing by a data transmission rate calculation unit according to the present disclosure. [Figure 6] 10 is an example of a flowchart illustrating a flow of processing by a data receiving device according to the present disclosure. [Figure 7] 10 is an example of a flowchart illustrating a flow of processing by a determination unit according to the present disclosure. [Figure 8] 1A and 1B are diagrams illustrating an overview of a data conversion process and an inverse data conversion process for transmission data according to the present disclosure. [Figure 9] 10 is an example of a flowchart illustrating a flow of processing by a data transmission rate calculation unit according to a modified example of the present disclosure. [Figure 10] 1 is a block diagram illustrating an example of a configuration of a data transmission system according to the present disclosure. [Figure 11] FIG. 10 is a diagram illustrating an example of a data format of a correspondence table according to the present disclosure. [Figure 12] 1 is a block diagram showing the hardware configuration of a data transmitting device and a data receiving device according to the present disclosure. [Figure 13] 1 is a block diagram illustrating an example of a configuration of a data transmission device according to the present disclosure. [Figure 14] 10 is a flowchart illustrating an example of a processing flow by a data transmission device according to the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0014] Each embodiment will be described below with reference to the drawings. In all drawings, the same or corresponding components are designated by the same reference numerals, and common descriptions will be omitted.

[0015] First Embodiment An embodiment of the present disclosure will be described below with reference to the drawings. As shown in FIG. 1, a data transmission / reception system 1 includes a data transmission device 2, a data reception device 3, a communication network 4, and communication lines 5-1 and 5-2. The communication network 4 may be, for example, a public network such as the Internet, a private network constructed using dedicated lines, or a virtual private network constructed using a public network. The data transmission device 2 and the data reception device 3 both include database units 20 and 30, and a database constructed in the database unit 20 of the data transmission device 2 is replicated in the database unit 30 of the data reception device 3.

[0016] The data transmission device 2 includes a database unit 20, a communication interface unit 21, a correspondence table storage unit 22, a timer unit 23, a conversion processing status storage unit 24, a transmission unit 25, an operation unit 26, a data transmission speed calculation unit 27, and a status change unit 28.

[0017] The database unit 20 has an internal storage area that serves as a database such as a relational database. The database unit 20 is capable of performing operations such as writing data, changing data, and deleting data on the internal storage area using a database language such as SQL (Structured Query Language). Every time an operation is performed on the storage area, the database unit 20 outputs data indicating the operation content (hereinafter referred to as operation content data) to the transmission unit 25.

[0018] The communication interface unit 21 is connected to the communication line 5-1 and is connected to the communication network 4 via the communication line 5-1. The communication line 5-1 may be a wired line or a wireless line. The communication interface unit 21 periodically measures the communication speed of the communication line 5-1 and records the latest communication speed in an internal storage area each time it measures it. Here, the communication speed of the communication line 5-1 measured by the communication interface unit 21 is the communication speed of the communication path from the communication interface unit 21 of the data transmitting device 2 to the communication interface unit 31 of the data receiving device 3.

[0019] The correspondence table storage unit 22 stores the correspondence table 40T shown in Fig. 2. The correspondence table 40T is a table in a data format having the items "key value" and "value value". In the "value value", several data components selected in advance from the data components that make up the operation content data output by the database unit 20 are recorded in advance in the column direction. The data components recorded in the "value value" item are all selected to be different.

[0020] The "key value" field stores in advance an element index that can identify each data component. Each element index is data with a data amount smaller than the data amount of the corresponding data component, and any data may be used as long as each element index is different. Figure 2 shows an example in which data with consecutive integer values ​​starting from "1" is used as the element index.

[0021] The timekeeping unit 23 is a clock, and upon receiving a time acquisition request signal, outputs the time at the time of reception to the source of the time acquisition request signal. The conversion processing status memory unit 24 stores conversion processing status information of either "processing required" or "processing not required."

[0022] The transmitting unit 25 transmits the operation content data output by the database unit 20 as transmission data, with the destination being the data receiving device 3, via the communication interface unit 21 and the communication line 5-1 to the data receiving device 3. If the conversion processing status information stored in the conversion processing status storage unit 24 is "processing required," the transmitting unit 25 applies data conversion processing to the transmission data before transmitting the transmission data. Here, the data conversion processing is a process of replacing a portion of the transmission data including a data component indicated in the "value" field of the correspondence table 40T with the element index indicated in the "key value" field of the record in the correspondence table 40T corresponding to the data component. Note that the data conversion processing also includes a process of adding a detection mark "@" to the beginning of each element index so that the portion of the element index included in the replaced transmission data can be detected.

[0023] When transmitting transmission data, the transmitting unit 25 outputs a time acquisition request signal to the timing unit 23 to acquire the time, and sets the acquired time as the time to start transmission (hereinafter referred to as the transmission time). The transmitting unit 25 associates the acquired transmission time and conversion process status information stored in the conversion process status storage unit 24 with the transmission data, and transmits the data. When transmitting the transmission data, the transmitting unit 25 transmits the transmission data at a data transmission rate calculated by the data transmission rate calculation unit 27.

[0024] When the operation unit 26 receives an operation from the user, it performs processing according to the received operation. When the operation unit 26 receives an input operation from the user regarding an operation on the storage area of ​​the database unit 20, it outputs a database operation instruction signal including operation content data indicating the operation on the storage area of ​​the database unit 20 to the database unit 20. When the operation unit 26 receives an input operation from the user regarding the rate at which the communication line 5-1 is used (hereinafter referred to as the communication line usage rate), which is a data transmission rate calculation condition, it outputs the communication line usage rate to the data transmission rate calculation unit 27.

[0025] The data transmission speed calculation unit 27 acquires the communication speed of the communication line 5-1 from the communication interface unit 21, and calculates the data transmission speed based on the acquired communication speed and the communication line usage rate output by the operation unit 26.

[0026] When the status change unit 28 receives a status change notification from the data receiving device 3, if the conversion processing status information stored in the conversion processing status storage unit 24 is "processing required", it rewrites it to "processing not required", and if the conversion processing status information is "processing not required", it rewrites it to "processing required".

[0027] The data receiving device 3 includes a database unit 30, a communication interface unit 31, a correspondence table storage unit 32, a timer unit 33, a receiving unit , and a determining unit .

[0028] The database unit 30, like the database unit 20, has an internal storage area that serves as a database such as a relational database. Like the database unit 20, the database unit 30 is capable of performing operations such as writing data, changing data, and deleting data on the internal storage area using the same database language as the database language used to operate the database unit 20.

[0029] The communication interface unit 31 is connected to the communication line 5-2, and is connected to the communication network 4 via the communication line 5-2. The communication line 5-2 may be a wired line or a wireless line.

[0030] Correspondence table storage unit 32 stores correspondence table 40R shown in Fig. 2, which has the same contents as correspondence table 40T stored in correspondence table storage unit 22. Timekeeping unit 33 is a clock, and upon receiving a time acquisition request signal, outputs the time at the time of reception to the source of the time acquisition request signal. The times of timekeeping units 23 and 33 are synchronized so that they show the same time.

[0031] The receiving unit 34 receives the transmission data, which is associated with the transmission time and conversion processing status information transmitted by the data transmitting device 2, via the communication line 5-2 and the communication interface unit 31. When the receiving unit 34 starts receiving the transmission data, it outputs a time acquisition request signal to the timing unit 33 to acquire the time, and sets the acquired time as the time to start receiving (hereinafter referred to as the reception time). The receiving unit 34 outputs the reception time and the received transmission time and conversion processing status information to the determining unit 35.

[0032] If the received conversion processing status information is "processing required," the receiving unit 34 applies to the transmission data a conversion processing that is the reverse of the data conversion processing performed by the transmitting unit 25 (hereinafter referred to as "inverse data conversion processing"). Here, the inverse data conversion processing is the following processing: That is, the "@" and the element index portion immediately following the "@" contained in the transmission data are detected. The detected "@element index" portion is replaced with the data component indicated in the "value" field of the record in the correspondence table 40R that corresponds to the element index.

[0033] If the received conversion processing status information is "processing required", the receiving unit 34 outputs the transmission data that has undergone the inverse data conversion processing to the database unit 30. If the received conversion processing status information is "processing not required", the receiving unit 34 outputs the transmission data as is to the database unit 30 without performing the inverse data conversion processing.

[0034] The determination unit 35 determines whether to cause the transmission unit 25 of the data transmission device 2 to perform data conversion processing based on the state of the communication path. Here, the state of the communication path refers to the state of the communication path from the communication interface unit 21 to the communication interface unit 31, which is formed by the communication line 5-1, the communication network 4, and the communication line 5-2. The state of the communication path is represented, for example, by the transmission time and reception time output by the reception unit 34. The determination unit 35 determines whether to transmit a state change notification to the data transmission device 2 based on the determination result and the conversion processing state information output by the reception unit 34.

[0035] <Processing of First Embodiment> The processing of the data transmission and reception system 1 will be described below with reference to FIGS. 3 to 8. FIG. 3 is a sequence diagram showing the overall flow of processing of the data transmission and reception system 1. It is assumed that the state before the processing shown in FIG. 3 is performed is as shown below. It is assumed that the correspondence table 40T is stored in the correspondence table storage unit 22, and the correspondence table 40R is stored in the correspondence table storage unit 32. It is assumed that the contents of the correspondence tables 40T and 40R are the same, as shown in FIG. 2. It is assumed that the contents of the database constructed in the internal storage area of ​​the database unit 20 are the same as the contents of the database constructed in the internal storage area of ​​the database unit 30. It is assumed that the conversion processing status information stored in the conversion processing status storage unit 24 may be either "processing required" or "processing not required."

[0036] The user inputs the communication line usage rate, which is a data transmission rate calculation condition, into the operation unit 26 of the data transmission device 2. Upon receiving this input operation, the operation unit 26 outputs the communication line usage rate to the data transmission rate calculation unit 27. The data transmission rate calculation unit 27 acquires the communication line usage rate output by the operation unit 26 and records the acquired communication line usage rate in an internal storage area (S1).

[0037] The user performs an input operation on the operation unit 26 regarding an operation on the storage area of ​​the database unit 20. When the operation unit 26 receives the input operation, it generates a database operation instruction signal including operation content data indicating the operation on the storage area of ​​the database unit 20, and outputs the generated database operation instruction signal to the database unit 20. When the database unit 20 receives the database operation instruction signal from the operation unit 26, it performs processing on its internal storage area in accordance with the operation content data included in the received database operation instruction signal (S2). After performing processing on its internal storage area in accordance with the data indicating the operation content, the database unit 20 outputs the operation content data to the transmission unit 25 (S3). When the transmission unit 25 receives the operation content data output by the database unit 20, the data transmission process shown in FIG. 4 is started (S4).

[0038] (Data transmission process) The transmitting unit 25 sets the captured operation content data as transmission data (Sa1). The transmitting unit 25 acquires conversion processing status information from the conversion processing status storage unit 24 (Sa2). The transmitting unit 25 determines whether the acquired conversion processing status information is "processing required" or "processing not required" (Sa3).

[0039] When the transmitting unit 25 determines that the conversion processing status information is "processing required" (Sa3, processing required), it refers to the correspondence table 40T stored in the correspondence table storage unit 22 and performs the above-mentioned data conversion processing. For example, when the content of the transmission data is the content shown in FIG. 8(a), the transmitting unit 25 converts the content of the transmission data into the content shown in FIG. 8(b) by the above-mentioned data conversion processing. Note that in FIG. 8(a), the data components that do not correspond to the data components shown in the "value" item of the correspondence table 40T, namely, parentheses, commas, single quotation marks, "10" indicated by reference numeral 51, and the date information "YYYY / MM / DD" indicated by reference numeral 52, are maintained without being replaced, as shown in FIG. 8(b) (Sa4).

[0040] When the transmitting unit 25 determines that the conversion processing status information is "processing not required" (Sa3, processing not required), or after the processing of Sa4, it outputs a data transmission rate calculation instruction signal to the data transmission rate calculation unit 27 (Sa5). When the data transmission rate calculation instruction signal is received from the transmitting unit 25, the data transmission rate calculation unit 27 starts the data transmission rate calculation processing shown in Fig. 5 (Sa6).

[0041] (Data transmission speed calculation process) In the process of S1 in Fig. 3, the data transmission rate calculation unit 27 reads out the communication line usage rate recorded in the internal storage area from the internal storage area (Sb1). The data transmission rate calculation unit 27 outputs a communication rate acquisition request signal to the communication interface unit 21. Upon receiving the communication rate acquisition request signal from the data transmission rate calculation unit 27, the communication interface unit 21 reads out the communication rate from the internal storage area and outputs the read communication rate to the transmitter 25. The data transmission rate calculation unit 27 acquires the communication rate output by the communication interface unit 21 (Sb2). The data transmission rate calculation unit 27 calculates the data transmission rate based on the communication rate and the communication line usage rate using the following equation (1).

[0042] Data transmission speed = communication speed × communication line usage rate / 8 (1)

[0043] In formula (1), the unit of data transmission speed is [byte / s (second)], which indicates the amount of data sent to communication line 5-1 per unit time. The unit of communication speed is [bps (bit per second)]. The unit of communication line usage rate is [%], and any value below 100% is set by the user in the S1 process. The right-hand side is divided by "8" to convert the unit of bits to the unit of bytes.

[0044] The data transmission rate calculation unit 27 outputs the calculated data transmission rate to the transmission unit 25 (Sb3), and ends the data transmission rate calculation process.

[0045] 4, the transmitting unit 25 takes in the data transmission rate output by the data transmission rate calculation unit 27. The transmitting unit 25 outputs a time acquisition request signal to the timing unit 23 to acquire the time, and sets the acquired time as the transmission time (Sa7).

[0046] The transmitting unit 25 associates the conversion processing status information and the transmission time acquired in the processing of Sa2 with the transmission data, and further adds data addressed to the data receiving device 3 to the transmission data to form the transmission data to be finally transmitted (Sa8). The transmitting unit 25 sends the transmission data to be finally transmitted to the communication line 5-1 via the communication interface unit 21 at the captured data transmission speed (Sa9). This completes the data transmission processing.

[0047] 3, the receiving unit 34 of the data receiving device 3 receives the transmission data transmitted by the data transmitting device 2 and transferred by the communication network 4 via the communication line 5-2 and the communication interface unit 31. When the receiving unit 34 receives the transmission data, the data receiving process shown in FIG. 6 is started (S5).

[0048] (Data reception processing) The receiving unit 34 outputs a time acquisition request signal to the timer unit 33 at the timing when it starts receiving transmission data to acquire the time, and sets the acquired time as the reception time (Sc1). The receiving unit 34 separates the conversion process status information and the transmission time from the received transmission data. The receiving unit 34 further removes data added by the transmitting unit 25, such as the destination, from the transmission data from which the conversion process status information and transmission time have been separated and removed (Sc2). The receiving unit 34 outputs the transmission time, reception time, and conversion process status information to the determining unit 35 (Sc3). The determining unit 35 takes in the transmission time, reception time, and conversion process status information output by the receiving unit 34, and starts the status change determining process shown in FIG. 7 (Sc4).

[0049] (Status change determination process) The determination unit 35 determines the delay time to be the time obtained by subtracting the transmission time from the reception time (Sd1). Strictly speaking, this delay time is the difference between the time that the transmission unit 25 obtained from the clock unit 23 and the time that the reception unit 34 obtained from the clock unit 33, but it can be considered to be the delay time caused by the transfer of transmission data via the communication lines 5-1 and 5-2 and the communication network 4. The determination unit 35 determines whether the delay time is less than a predetermined allowable delay time (Sd2).

[0050] If the determination unit 35 determines that the delay time is less than the allowable delay time (Sd2, Yes), it determines whether the acquired change processing status information is "processing required" or "processing not required" (Sd3). Assume that the determination unit 35 determines that the change processing status information is "processing required" (Sd3, processing required). In this case, since the delay time is less than the allowable delay time, it is within the allowable range, and the data transmission device 2 does not need to perform data conversion processing, but the data transmission device 2 is in a state where data conversion processing is being performed. Therefore, it is necessary to have the data transmission device 2 stop the data conversion processing. Therefore, the determination unit 35 sends a status change notification addressed to the data transmission device 2 to the communication line 5-2 via the communication interface unit 31 (Sd5), and ends the status change determination process.

[0051] In the process of Sd3, it is assumed that the determination unit 35 determines that the change processing status information is "processing not required" (Sd3, processing not required). In this case, since the delay time is less than the allowable delay time, the delay time is within the allowable range, and the data transmission device 2 does not need to perform data conversion processing, which corresponds to a state in which data conversion processing is not being performed in the data transmission device 2. Therefore, it is sufficient to maintain the status without changing it, and the determination unit 35 ends the status change determination process without transmitting a status change notification to the data transmission device 2.

[0052] In the process of Sd2, if the determination unit 35 determines that the delay time is not less than the allowable delay time (Sd2, No), it determines whether the acquired change processing status information is "processing required" or "processing not required" (Sd4). Assume that the determination unit 35 determines that the change processing status information is "processing not required" (Sd4, processing not required). In this case, since the delay time is not less than the allowable delay time, the delay time is outside the allowable range, and the data transmission device 2 needs to perform data conversion processing, but this corresponds to a state in which the data transmission device 2 is not performing data conversion processing. Therefore, it is necessary to have the data transmission device 2 start data conversion processing. Therefore, the determination unit 35 performs the process of Sd5 and ends the status change determination process.

[0053] In the process of Sd4, it is assumed that the determination unit 35 determines that the change processing status information is "processing required" (Sd3, processing required). In this case, since the delay time is not less than the allowable delay time, the delay time is outside the allowable range, and the data transmission device 2 needs to perform data conversion processing, which corresponds to a state in which data conversion processing is being performed in the data transmission device 2. Therefore, since it is sufficient to maintain the status without changing it, the determination unit 35 ends the status change determination process without transmitting a status change notification to the data transmission device 2.

[0054] Returning to FIG. 6, after processing Sc3, the receiving unit 34 determines whether the conversion process status information is "processing required" or "processing not required" (Sc5). Assume that the receiving unit 34 determines that the conversion process status information is "processing required" (Sc5, processing required). In this case, the receiving unit 34 applies the above-mentioned inverse data conversion process to the transmission data finally obtained in the processing of Sc2, i.e., the transmission data from which the conversion process status information, the transmission time, and data added by the transmitting unit 25, such as the destination, have been removed. As a result, the content of the transmission data shown in FIG. 8(b) becomes the content shown in FIG. 8(c), which is the same content as the content of FIG. 8(a) output by the database unit 20 of the data transmitting device 2 to the transmitting unit 25 (Sc6). The receiving unit 34 outputs the transmission data after applying the inverse data conversion process to the database unit 30 (Sc7), and ends the data receiving process.

[0055] In the process of Sc5, the receiving unit 34 determines that the conversion process status information is "processing not required" (Sc5, processing not required). In this case, since the data conversion process has not been applied to the transmission data, the receiving unit 34 does not perform the reverse data conversion process, but outputs the transmission data as is to the database unit 30 (Sc7), and ends the data reception process.

[0056] Returning to Fig. 3, the process of S6 performed when the determination unit 35 of the data receiving device 3 transmits a state change notification to the data transmitting device 2 in the process of Sd5 in Fig. 7 will be described. The state change unit 28 of the data transmitting device 2 receives the state change notification sent by the data receiving device 3 to the communication line 5-2 and transferred by the communication network 4, via the communication line 5-1 and the communication interface unit 21. If the conversion processing state information stored in the conversion processing state storage unit 24 is "processing required", the state change unit 28 rewrites it to "processing not required", and if the conversion processing state information is "processing not required", the state change unit 28 rewrites it to "processing required" (S6).

[0057] When the database unit 30 of the data receiving device 3 receives the transmission data output by the receiving unit 34, it performs processing on its internal storage area in accordance with the received transmission data, i.e., the operation content data (S7). As a result, the same operation as that performed on the internal storage area of ​​the database unit 20 is performed on the internal storage area of ​​the database unit 30. As a result, the contents of the database constructed in the internal storage area of ​​the database unit 20 and the contents of the database constructed in the internal storage area of ​​the database unit 30 become identical, and the duplication is completed.

[0058] Thereafter, every time the user of the data transmission device 2 performs an input operation on the operation unit 26 regarding an operation on the storage area of ​​the database unit 20, the processing from S2 onward in FIG. 3 is performed.

[0059] <Effects of the First Embodiment> In the data transmission and reception system 1, the data transmission device 2 can set a communication line usage rate as a data transmission rate calculation condition. The data transmission device 2 calculates the data transmission rate from the communication speed of the communication line 5-1 measured by the communication interface unit 21 and the communication line usage rate, and transmits the transmission data at the calculated data transmission rate. Therefore, by changing the value of the communication line usage rate, it is possible to change the communication bandwidth allocated to the transmission data transmitted by the data transmission device 2 on the communication line 5-1. This method is not performed in cooperation with the receiving side, as in Patent Document 1, and therefore the data transmission device 2 can be applied to a form in which data is unilaterally transmitted from the data transmission device 2 to the data receiving device 3, as in the data transmission and reception system 1.

[0060] By using the data transmission and reception system 1, for example, even if a plurality of data transmission devices 2 are connected to the communication line 5-1, the communication bandwidth of the communication line 5-1 can be allocated equally to each of the data transmission devices 2, making it possible to make the communication line 5-1 less susceptible to congestion. In this way, the data transmission system 1 can reduce the possibility of congestion occurring compared to when the calculation and adjustment of the data transmission rate are not performed.

[0061] In the data transmission / reception system 1, the data transmission rate is calculated by multiplying the communication rate of the communication line 5-1 by the communication line usage rate. Therefore, even if the communication rate of the communication line 5-1 is low, it is possible to calculate a data transmission rate that corresponds to that low communication rate. Therefore, even in an environment where only a communication line 5-1 with a low communication rate is available, such as an isolated island or a remote area, it is possible to determine a data transmission rate that corresponds to the environment, and it is possible to make the communication line 5-1 in a state where congestion is unlikely to occur.

[0062] In the data transmission / reception system 1, the communication interface unit 21 periodically measures the communication speed of the communication line 5-1, so even if the communication speed fluctuates, the data transmission speed can be changed to follow the fluctuation. Therefore, if congestion is about to occur in the communication line 5-1 and the communication speed decreases, the data transmission speed also decreases accordingly, so that the state of the communication line 5-1 can be made less susceptible to congestion.

[0063] In the data transmission and reception system 1, the data transmission device 2 further performs data conversion processing before transmitting the transmission data, and the data receiving device 3 performs inverse data conversion processing on the received transmission data to restore the operation content data output by the database unit 20. In the data conversion processing, data components of the transmission data that are pre-stored in the correspondence table 40T are replaced with element indexes with smaller data volumes than the data components, thereby reducing the data volume. Algorithm-based data compression techniques generally have limitations on the compression that depend on the algorithm. In contrast, data conversion processing reduces the data volume of the transmission data itself. Therefore, in the data transmission and reception system 1, for example, when the transmitting unit 25 performs data conversion processing, the data that has undergone the data conversion processing is compressed using an algorithm, and the receiving unit 34 decompresses the received transmission data using an algorithm before performing inverse data conversion processing. In this way, the data transmission and reception system 1 can achieve a higher compression rate than a configuration that only performs algorithm-based compression on the transmission data without performing data conversion processing, thereby further reducing the data volume of the transmission data and improving throughput.

[0064] In the data transmission and reception system 1, even if the transmission data that has undergone data conversion processing by the data transmission device 2 is leaked during transfer, the reverse data conversion processing cannot be performed unless the receiving side has a correspondence table 40R with the same contents as the correspondence table 40T. This improves the confidentiality of the transmission data.

[0065] Furthermore, in the data transmission / reception system 1, the data conversion process and its corresponding inverse data conversion process are not always performed, but are selectively performed depending on the length of the communication delay. That is, if the delay is within the allowable range, the communication lines 5-1, 5-2 and the communication network 4 are deemed to have sufficient communication bandwidth, and the data conversion process is not performed. If the delay is outside the allowable range, the communication lines 5-1, 5-2 and the communication network 4 are deemed to have limited communication bandwidth, and the data conversion process is performed to reduce the amount of transmitted data. In this way, when the communication lines 5-1, 5-2 and the communication network 4 are deemed to have sufficient communication bandwidth, the processing load associated with data conversion in the data transmission device 2 and the data receiving device 3 can be reduced. On the other hand, when the communication lines 5-1, 5-2 and the communication network 4 are deemed to have limited communication bandwidth, the processing load associated with data conversion in the data transmission device 2 and the data receiving device 3 increases, but the amount of transmitted data can be reduced, thereby mitigating the impact of communication delays.

[0066] In the data transmission / reception system 1, the initial state of the conversion processing status memory unit 24 of the data transmission device 2 can be either "processing required" or "processing not required." However, if the initial state is set to "processing not required," data can be transmitted and received with a reduced processing load associated with data conversion in the data transmission device 2 and the data receiving device 3 from the initial state until the delay time becomes equal to or exceeds the allowable delay time.

[0067] Furthermore, in the data transmission / reception system 1, the communication line usage ratio is set at the timing of processing S1, but it is not limited to the timing of processing S1, and the communication line usage ratio may be set at the timing of Sb1 in Figure 5, that is, each time transmission data is sent.

[0068] <Modification of the first embodiment> In the data transmission / reception system 1, the data transmission rate calculation unit 27 calculates the data transmission rate based on the communication rate of the communication line 5-1 and the communication line usage rate using equation (1), as shown in Fig. 5. Alternatively, the data transmission rate calculation unit 27 may calculate the data transmission rate using the following procedure.

[0069] In the process of S1 in Fig. 3, the user inputs the permissible transmission time into the operation unit 26 of the data transmission device 2 instead of the communication line usage rate as a data transmission rate calculation condition. Upon receiving this input operation, the operation unit 26 outputs the permissible transmission time to the data transmission rate calculation unit 27. The data transmission rate calculation unit 27 acquires the permissible transmission time output by the operation unit 26 and records the acquired permissible transmission time in an internal storage area. Here, the permissible transmission time is the time allowed for the time required to transmit one piece of transmission data, that is, the time allowed for the time from the start of transmission of the transmission data to the completion of transmission.

[0070] In the process of Sa5 in Fig. 4, when the transmitter 25 outputs a data transmission rate calculation instruction signal to the data transmission rate calculator 27, it outputs transmission data together with the data transmission rate calculation instruction signal. As the data transmission rate calculation process of Sa6 in Fig. 4, the process shown in Fig. 9 is applied instead of the process shown in Fig. 5. The process shown in Fig. 9 will be described below.

[0071] When the data transmission rate calculation unit 27 receives transmission data and a data transmission rate calculation instruction signal from the transmitter 25, it takes in the received transmission data and reads out the permissible transmission time recorded in the internal storage area in the process of S1 in Fig. 3 from the internal storage area (Se1). The data transmission rate calculation unit 27 detects the amount of the taken-in transmission data (Se2). Based on the amount of the transmission data and the permissible transmission time, the data transmission rate calculation unit 27 calculates the data transmission rate using the following equation (2) (Se3).

[0072] Data transmission speed = data volume / transmission time (2)

[0073] In equation (2), the unit of the data transmission speed is [byte / s], the same as in equation (1), the unit of the data amount is [byte], and the unit of the permissible transmission time is [s (second)].

[0074] The data transmission rate calculation unit 27 outputs a communication rate acquisition request signal to the communication interface unit 21. When the communication interface unit 21 receives the communication rate acquisition request signal from the data transmission rate calculation unit 27, it reads the communication rate from an internal storage area and outputs the read communication rate to the transmitter 25. The data transmission rate calculation unit 27 acquires the communication rate output by the communication interface unit 21 (Se4).

[0075] Since the acquired communication speed is in units of [bps], the data transmission speed calculation unit 27 divides it by 8 to convert it into a value in units of [bytes / s]. The data transmission speed calculation unit 27 determines whether the data transmission speed [bytes / s] exceeds the communication speed [bytes / s] (Se5).

[0076] If the data transmission rate calculation unit 27 determines that the data transmission rate [byte / s] does not exceed the communication rate [byte / s] (Se5, No), it outputs the data transmission rate to the transmitter 25 (Se7) and terminates the data transmission rate calculation process.

[0077] In the process of Se5, if the data transmission rate calculation unit 27 determines that the data transmission rate [byte / s] exceeds the communication rate [byte / s] (Se5, Yes), it outputs an error notification indicating that the data transmission rate exceeds the communication rate of the communication line 5-1 to, for example, a display or the like of the data transmission device 2 (not shown). The data transmission rate calculation unit 27 outputs a data transmission rate unset response signal indicating that the data transmission rate cannot be determined to the transmission unit 25 (Se6), and ends the data transmission rate calculation process.

[0078] In this case, the user may refer to the error notification output on a display or the like and perform the S1 process again, setting a longer transmission allowable time than the previous transmission allowable time, and adjusting the data transmission speed so that it is equal to or lower than the communication speed.

[0079] Upon receiving the data transmission rate unset response signal from the data transmission rate calculation unit 27, the transmitter 25 may transmit the transmission data at, for example, a predetermined data transmission rate. Here, the predetermined data transmission rate may be, for example, a rate approximately equal to the average data transmission rate calculated by the data transmission rate calculation unit 27 under normal operating conditions, or a rate even lower than the average. Furthermore, the transmitter 25 may calculate the data transmission rate by the following process when receiving the data transmission rate unset response signal. The transmitter 25 predetermines a communication line usage rate that is sufficiently smaller than 100%, for example, approximately 10%. The transmitter 25 acquires the communication rate of the communication line 5-1 from the communication interface unit 21, calculates the data transmission rate by substituting the acquired communication rate into equation (1) that applies the predetermined communication line usage rate, and performs the process of Sa9 in FIG. 4 using the calculated data transmission rate.

[0080] In the case of the data transmission rate calculation process shown in Fig. 9, the amount of transmission data to be finally transmitted, obtained in the process of Sa8, may be detected in the process of Se2 in order to calculate a more accurate data transmission rate. In this case, the data transmission rate calculation process of Sa6 in Fig. 4 is performed after the process of Sa8 and before the process of Sa9.

[0081] 9 is applied as the data transmission rate calculation process, the data transmitting device 2 can set the permissible transmission time as a data transmission rate calculation condition. In this case, the data transmitting device 2 calculates the data transmission rate from the amount of data to be transmitted and the permissible transmission time, and transmits the transmission data at the calculated data transmission rate. Therefore, by changing the permissible transmission time, it is possible to change the communication bandwidth allocated to the transmission data transmitted by the data transmitting device 2 on the communication line 5-1. This method is also not performed in cooperation with the receiving side, as in Patent Document 1, and therefore the data transmitting device 2 can be applied to a form in which data is unilaterally transmitted from the data transmitting device 2 to the data receiving device 3, as in a modified example of the data transmission and reception system 1.

[0082] For example, suppose that multiple data transmission devices 2 are connected to the communication line 5-1, and each of the data transmission devices 2 is in a state where it takes a long time to transmit the transmission data it sends. Even in this state, in the modified example of the data transmission and reception system 1, if there is a data transmission device 2 transmitting transmission data for which the permissible transmission time can be extended, the user can, at their own discretion, set the permissible transmission time to a longer value and reduce the data transmission rate. In other words, if congestion is likely to occur in the communication line 5-1, the user can, at their own discretion, reduce the communication bandwidth used by the data transmission device 2, thereby making the communication line 5-1 less susceptible to congestion. Furthermore, if the amount of transmission data is large but it is okay for it to take a long time to transmit, by setting a long permissible transmission time for the transmission data in advance, it is possible to prevent the communication bandwidth of the communication line 5-1 from being monopolized by the large amount of transmission data, thereby enabling efficient use of the communication line 5-1.

[0083] In the modified example of the data transmission / reception system 1, the allowable transmission time is set at the timing of the S1 process, but it is not limited to the timing of the S1 process, and the allowable transmission time may be set at the timing of Se1 in Fig. 9, that is, each time transmission data is transmitted. If the data amount for each transmission data differs greatly, a more appropriate data transmission speed can be obtained by setting the allowable transmission time at the timing of Se1 rather than at the timing of the S1 process.

[0084] It is assumed that the allowable transmission time is set by a predetermined artificial agreement, for example, so that the data transmission rate calculated by the data transmission rate calculation unit 27 in the process of Se3 in Fig. 9 is equal to or lower than the communication rate of the communication line 5-1. In this case, the process of Fig. 9 may not include the processes of Se4, Se5, and Se6, and may be configured so that the process of Se7 is performed after the process of Se3.

[0085] In the above-described data transmission / reception system 1 and its modified example, the operation unit 26 of the data transmission device 2 outputs operation content data indicating operations on the storage area of ​​the database unit 20 to the transmission unit 25. In contrast to this, the data transmission device 2 may be provided with a processing unit (not shown) that performs some kind of processing, and the processing unit may output operation content data indicating operations on the storage area of ​​the database unit 20 to the transmission unit 25 without user intervention.

[0086] In the above-described data transmission / reception system 1 and its variations, the transmission unit 25 adds a detection mark "@" before the element index in the data conversion process. However, data with "@" added before the element index described with reference to Fig. 2, i.e., data beginning with a detection mark, may be recorded as an element index in the "key value" field of the correspondence tables 40T, 40R.

[0087] Second Embodiment An embodiment of the present disclosure will be described with reference to the drawings. As shown in Fig. 10, a data transmission / reception system 1a includes a data transmission device 2a, a data reception device 3a, a communication network 4, and communication lines 5-1 and 5-2. The data transmission device 2a and the data reception device 3a have a relationship in which, for example, the data reception device 3a is a server device that performs various processes, and the data transmission device 2a is a terminal device that remotely causes the data reception device 3a to perform various processes.

[0088] The data receiving device 3a includes a communication interface unit 21, a correspondence table storage unit 22a, a timer unit 23, a conversion processing status storage unit 24, a transmitter 25, an operation unit 26a, a data transmission speed calculation unit 27, and a status change unit .

[0089] When the operation unit 26a receives an operation from the user, it performs processing according to the received operation. When the operation unit 26a receives an input operation from the user to cause the data receiving device 3a to execute various processes, it outputs processing content data indicating the processes to be executed by the data receiving device 3a to the transmission unit 25. Like the operation unit 26, when the operation unit 26a receives an input operation from the user to input a communication line usage rate, which is a data transmission rate calculation condition, it outputs the communication line usage rate to the data transmission rate calculation unit 27.

[0090] The correspondence table storage unit 22a stores the correspondence table 40aT shown in FIG. 11. Similar to the correspondence table 40T shown in FIG. 2, the correspondence table 40aT is a table in a data format having the fields "key value" and "value value." In the "value value," several data components selected in advance from the data components that make up the processing content data output by the operation unit 26a are recorded in advance in the column direction. Note that the data components recorded in the "value value" field are all selected to be different. In the "key value" field, an element index generated under the same conditions as the element index recorded in the "key value" field of the correspondence table 40T is recorded.

[0091] The data receiving device 3a includes a database unit 30, a communication interface unit 31, a correspondence table storage unit 32a, a timer unit 33, a receiver unit 34, a determination unit 35, a process execution unit 36, and a storage unit 37. The correspondence table storage unit 32a stores a correspondence table 40aR shown in Fig. 11, which has the same contents as the correspondence table 40aT stored in the correspondence table storage unit 22a.

[0092] The process execution unit 36 ​​executes processing in accordance with the transmission data output by the receiving unit 34. The storage unit 37 stores various types of data to be processed by the process execution unit 36. As an example, FIG. 10 shows an example in which executable data named "Program 1" (hereinafter referred to as "Program 1 execution data"), data written in HTML named "HTML (Hyper Text Markup Language) 1", executable data named "Web Browser" (hereinafter referred to as "Web Browser execution data"), and data named "Data 1" are stored. Here, the web browser execution data is, for example, executable data of an application program that reads HTML data, performs syntax analysis, and displays text and images on an output device such as a display based on the results of the syntax analysis.

[0093] <Processing of the second embodiment> The processing by the data transmission and reception system 1a is the same as that of the data transmission and reception system 1 described with reference to FIGS. 3 to 7 except for the processing described below, except that operation content data is replaced with processing content data. In the data transmission and reception system 1a, the following processing is performed instead of the processing of S2 and S3 in FIG. 3. The user performs an input operation on the operation unit 26a to cause the data receiving device 3a to execute, for example, "Program 1." Specifically, the user performs an input operation on the operation unit 26a to input the character string "Program 1." Upon receiving this input operation, the operation unit 26a outputs processing content data indicating the character string "Program 1" to the transmission unit 25. When the transmission unit 25 receives the processing content data output by the operation unit 26a, the data transmission processing shown in FIG. 4 is started as the processing of S4.

[0094] 4, the transmitting unit 25 performs the data conversion process by referring to the correspondence table 40aT stored in the correspondence table storage unit 22a, instead of referring to the correspondence table 40T stored in the correspondence table storage unit 22. Therefore, the following process is performed in the process of Sa4 in Fig. 4. The transmitting unit 25 replaces the data component "Program 1" included in the transmission data with an element index of "1" and adds "@" before the element index.

[0095] In the process of Sc6 in Fig. 6, the receiving unit 34 performs the inverse data conversion process by referring to the correspondence table 40aR stored in the correspondence table storage unit 32a, instead of referring to the correspondence table 40R stored in the correspondence table storage unit 32. Therefore, in the process of Sc6 in Fig. 6, the following process is performed: The receiving unit 34 replaces the part "@1" included in the transmission data with "Program 1".

[0096] The following process is performed as the process of Sc7 in FIG. 6. Instead of outputting the transmission data to the database unit 30, the receiving unit 34 outputs the transmission data to the processing execution unit 36. When the processing execution unit 36 ​​receives the transmission data output by the receiving unit 34, it executes processing in accordance with the received transmission data, i.e., the processing content data. As described above, when the user performs an input operation on the operation unit 26a to input the character string "Program 1," the processing execution unit 36 ​​receives the transmission data containing the character string "Program 1." Therefore, the processing execution unit 36 ​​reads the execution data for Program 1 from the storage unit 37 and performs processing to execute Program 1 in the data receiving device 3a based on the read execution data for Program 1.

[0097] When a user performs an input operation on the operation unit 26a to input the character string "HTML1," the processing execution unit 36 ​​retrieves the transmission data containing the character string "HTML1." The processing execution unit 36 ​​reads the HTML1 data from the storage unit 37 according to the character string "HTML1" and detects that the read HTML1 data is data written in HTML, for example, from the file extension added to the data's file name. Because the HTML1 data is written in HTML, the processing execution unit 36 ​​reads web browser execution data from the storage unit 37 and executes the web browser on the data receiving device 3a based on the read web browser execution data. The processing execution unit 36 ​​then loads the HTML1 data into the web browser. The web browser then parses the HTML1 data and, based on the results of the syntax analysis, displays text and images on, for example, a display (not shown) of the data receiving device 3a.

[0098] When the user performs an input operation on the operation unit 26a to input the character string "delete data 1," the process execution unit 36 ​​receives the transmission data containing the character string "delete data 1." Therefore, the process execution unit 36 ​​performs a process to delete the data 1 stored in the storage unit 37 in accordance with the character string "delete data 1."

[0099] When a user performs an input operation on the operation unit 26a to input the character string "DB1 operation content 1," the process execution unit 36 ​​retrieves the transmission data containing the character string "DB1 operation content 1." Here, it is assumed that DB1 is pre-associated with the database unit 30 of the data receiving device 3a. In this case, the process execution unit 36 ​​performs an operation corresponding to "operation content 1" on the database unit 30 in accordance with the character string "DB1 operation content 1." Note that the character string "operation content 1" is specifically a character string indicating an operation such as writing data, changing data, or deleting data to be performed on a database expressed in a database language such as that shown in FIG. 8(a).

[0100] <Effects of the second embodiment> Comparing the configuration of the data transmission and reception system 1 with the configuration of the data transmission and reception system 1a, there are the following differences: In the data transmission and reception system 1, the content of the transmission data transmitted from the data transmission device 2 to the data reception device 3 is data related to database operations, whereas in the data transmission and reception system 1a, the content of the transmission data transmitted from the data transmission device 2a to the data reception device 3a is data related to processing to be executed by the data reception device 3a. Also, the correspondence tables 40T, 50T stored in the correspondence table storage units 22, 32 and the correspondence tables 40aT, 50aT stored in the correspondence table storage units 22a, 32a differ in that, in the data components stored in the "value" field, one is data indicating an operation on the database, and the other is data indicating processing to be executed by the data reception device 3a.

[0101] However, these differences are merely in the content of the data, and are the same in that the transmitting unit 25 replaces data components with element indexes, and the receiving unit 34 replaces element indexes with data components, and also in that the transmitting unit 25 transmits transmission data at a data transmission rate calculated by the data transmission rate calculation unit 27. Therefore, the data transmission and reception system 1a achieves the same effects as the data transmission and reception system 1.

[0102] In the data transmission and reception system 1a, similarly to the data transmission and reception system 1, data to which "@" is added before the element index described with reference to FIG. 11, i.e., data beginning with a detection mark, may be recorded as an element index in the "key value" field of the correspondence tables 40aT, 40aR. In the data transmission and reception system 1a, since the transmission data after the data conversion process contains only one element index, the element index portion can be detected even without the detection mark "@". Therefore, the transmission unit 25 does not need to add "@" before the element index in the data conversion process. In this case, the reception unit 34 can perform the inverse data conversion process assuming that "@" is not included in the transmission data.

[0103] In the data transmission / reception system 1a, the operation unit 26a of the data transmission device 2a outputs processing content data indicating the processing to be executed by the data receiving device 3a to the transmission unit 25. Alternatively, the data transmission device 2a may be provided with a processing unit (not shown) that performs some kind of processing, and the processing unit may output processing content data indicating the processing to be executed by the data receiving device 3a to the transmission unit 25 without user intervention. A data transmission device 2a equipped with such a processing unit may be used, for example, as an IoT (Internet of Things) device installed outdoors. IoT devices are often connected via low-speed wireless lines, and the data measured by sensors equipped in IoT devices may be enormous in volume. However, some IoT devices do not require real-time performance and may take a long time to transmit to a server device. Therefore, a data transmission device 2a that can adjust the data transmission speed and reduce the amount of transmitted data may be suitable as an IoT device.

[0104] The data transmission and reception system 1a may be configured to employ a modification of the data transmission and reception system 1 described with reference to FIG.

[0105] <Modifications regarding "state of communication path" in the above embodiment> In the above-described data transmission / reception systems 1, 1a, and their variations, the determination unit 35 determines whether to cause the transmission unit 25 of the data transmission device 2 to perform data conversion processing based on the state of the communication path. As described above, the state of the communication path is the state of the communication path from the communication interface unit 21 to the communication interface unit 31, which is formed by the communication line 5-1, the communication network 4, and the communication line 5-2. In the above-described embodiment, as a specific example, the state of the communication path is expressed as a delay time, which is the difference between the reception time, which is the time when the reception unit 34 starts receiving the transmission data, and the transmission time, which is the time when the transmission unit 25 starts transmitting the transmission data. Alternatively, the state of the communication path may be expressed as the difference between the reception completion time, which is the time when the reception unit 34 completes receiving the transmission data, and the transmission time.

[0106] When the "reception completion time" is used instead of the "reception time," the receiving unit 34, when performing the process of Sc1 in FIG. 6, outputs a time acquisition request signal to the timer unit 33 when it completes reception of the transmission data, rather than outputting a time acquisition request signal to the timer unit 33 when it starts receiving the transmission data. The receiving unit 34 acquires the time output by the timer unit 33 and sets the acquired time as the reception completion time. The "reception time" is then replaced with the "reception completion time," and the time obtained by subtracting the transmission time from the reception completion time is set as the delay time. In this case, the delay time includes a factor that varies depending on the state of the communication path and a factor that varies depending on the amount of transmission data. In the above-described embodiment using the "reception time," the predetermined allowable delay time used in the process of Sd2 in FIG. 7 can be determined by taking into account the former factor that varies depending on the state of the communication path. However, when the "reception completion time" is used, the predetermined allowable delay time must be determined by taking into account both factors. Therefore, if the amount of data to be transmitted varies for each piece of transmitted data, it is necessary to determine the allowable delay time in advance, taking into consideration the amount of variation, or to change the allowable delay time for each piece of transmitted data.

[0107] When the allowable delay time is changed for each piece of transmission data, for example, the transmitter 25 calculates the time required to transmit the transmission data (hereinafter referred to as the transmission time) by dividing the amount of transmission data by the data transmission speed. The transmitter 25 calculates the allowable delay time by adding the time required to transfer the transmission data via the communication paths of the communication line 5-1, the communication network 4, and the communication line 5-2 to the calculated transmission time. When transmitting transmission data, the transmitter 25 associates the allowable delay time with the transmission data and transmits it. The receiver 34 outputs the allowable delay time to the determiner 35 when outputting the reception completion time and the transmission time to the determiner 35. In the process of Sd2, the determiner 35 makes a determination using the allowable delay time output by the receiver 34, rather than a predetermined allowable delay time.

[0108] <Other Modifications of the Above Embodiment> In the above-described data transmission / reception systems 1, 1a, and their variations, FIGS. 2 and 11 show data of consecutive integer values ​​equal to or greater than 1 as an example of the element index recorded in the "key value" field of the correspondence tables 40T, 40R, 40aT, and 40aR. As described above, each element index is data with a data amount smaller than the data amount of the corresponding data component, and any data may be used as long as each element index is different. Therefore, the element index may be, for example, any numeric value or any character string data, or binary value data, or each element index may be hash value data calculated from the corresponding data component.

[0109] In the data transmission / reception systems 1, 1a, and their variations, the transmitter 25 transmits the final transmission data obtained in the process Sa8 in FIG. 4 at the data transmission rate in the process Sa9. Alternatively, the transmitter 25 may create a file in the process Sa8, associating the transmission data with the conversion processing status information and the transmission time, without adding data addressed to the data receiving device 3, and record the file in an internal storage area of ​​the data transmitting device 2, 2a. In this case, the transmitter 25 establishes a file transfer link with the receiver 34 in the process Sa9 using a file transfer procedure. The transmitter 25 reads the file from the internal storage area and transfers the read file through the established link at the data transmission rate. When the receiver 34 starts receiving the file through the link, it performs the process Sc1 and records the received file in an internal storage area of ​​the data receiving device 3, 3a. 6, the receiving unit 34 reads a file from an internal storage area and separates the read file into conversion processing status information, a sending time, and sending data. Because this sending data does not include data such as the destination that was added by the sending unit 25, the receiving unit 34 uses the sending data as is in the processing of Sc6 and Sc7.

[0110] In the above-described data transmission / reception systems 1, 1a and their variations, the data transmission devices 2, 2a transmit conversion process status information to the data receiving devices 3, 3a. Alternatively, the data transmission devices 2, 2a may not transmit conversion process status information to the data receiving devices 3, 3a, for example, by using the following configuration. For example, the data receiving devices 3, 3a may be provided with a conversion process status storage unit that stores conversion process status information indicating either "processing required" or "processing not required." Upon startup of the data receiving devices 3, 3a, the contents stored in the conversion process status storage unit of the data receiving devices 3, 3a are matched with the contents of the conversion process status storage unit 24 of the data transmitting devices 2, 2a. Instead of referencing the conversion process status information transmitted from the data transmitting devices 2, 2a, the receiving unit 34 refers to the conversion process status information stored in the conversion process status storage unit of the data receiving devices 3, 3a. In the process of Sd5 in FIG. 7, when transmitting the status change notification, the determination unit 35 rewrites the conversion processing status information stored in the conversion processing status storage unit of the data receiving device 3, 3a, which indicates "processing required," to "processing not required," and if "processing not required," to "processing required." In this case, due to the time difference between the timing at which the determination unit 35 rewrites the conversion processing status information in the conversion processing status storage unit of the data receiving device 3, 3a and the timing at which the process of S6 in FIG. 3 is performed, a temporary mismatch occurs between the contents stored in the conversion processing status storage unit 24 and the contents of the conversion processing status storage unit of the data receiving device 3, 3a. However, this time difference is short, approximately the time difference required to transmit the status change notification. Therefore, in this manner, the determination unit 35 of the data receiving device 3, 3a can obtain the conversion processing status information of the data transmitting device 2, 2a without transmitting the conversion processing status information from the data transmitting device 2, 2a to the data receiving device 3, 3a.

[0111] In the above-described data transmission / reception systems 1, 1a and their variations, the data transmission devices 2, 2a may not include the correspondence table storage units 22, 22a, but the correspondence table storage units 22, 22a may be provided in external storage devices connected to the data transmission devices 2, 2a. Similarly, the data reception devices 3, 3a may not include the correspondence table storage units 32, 32a, but the correspondence table storage units 32, 32a may be provided in external storage devices connected to the data reception devices 3, 3a. In this case, the external storage device may be a server device connected to the communication network 4 and connected to the data transmission devices 2, 2a and the data reception devices 3, 3a via the communication network 4. In this way, when the external storage device is a server device connected to the communication network 4, instead of connecting two external storage devices corresponding to the transmitting and receiving sides to the communication network 4, one external storage device may be connected to the communication network 4 and shared by both the transmitting and receiving sides.

[0112] In the above-mentioned data transmission / reception systems 1, 1a, and their variations, the communication interface unit 21 is configured to periodically measure the communication speed of the communication line 5-1, but it may also be configured to repeatedly measure the communication speed of the communication line 5-1 at irregular intervals.

[0113] In the above-described data transmission / reception systems 1, 1a, and their variations, the receiving unit 34 performs processing of Sc5 after processing of Sc3 in the processing of FIG. 6, but may also perform processing of Sc5 in parallel with processing of Sc3 after processing of Sc2.

[0114] In the data transmission / reception systems 1, 1a, and their variations, the determination unit 35 performs the state change determination process of Fig. 7, in which the determination process of Sd2 is followed by the determination process of Sd3 or Sd4. The order of these two determination processes is an example, and the order of the two determination processes may be reversed. That is, the determination unit 35 may perform the process of determining whether the conversion processing status information is "processing required" or "processing not required," and then perform the process of determining whether the allowable delay time exceeds the delay time.

[0115] Furthermore, in the configuration of the above embodiment, in Sd2 shown in FIG. 7, a determination process of "whether it is less than" is performed, but the determination process of "whether it is less than" is merely an example, and depending on how the threshold value, the allowable delay time, is defined, it may be replaced with a determination process of "whether it is equal to or less than this."

[0116] <Hardware configuration> 12 is a diagram illustrating an example of the hardware configuration of the data transmitting device 2, 2a and the data receiving device 3, 3a shown in FIG. 1 and FIG. 10 according to the present disclosure. The data transmitting device 2, 2a and the data receiving device 3, 3a according to the present disclosure are computers including, for example, a central processing unit (CPU) 101, a random access memory (RAM) 102, a read only memory (ROM) 103, an auxiliary storage device 104, an interface module 105, and an input / output module 106. The CPU 101, the RAM 102, the ROM 103, the auxiliary storage device 104, the interface module 105, and the input / output module 106 are interconnected by a bus 107. The auxiliary storage device 104 is, for example, a hard disk drive (HDD) or a solid state drive (SDD). The interface module 105 is, for example, included in the communication interface unit 21, 31. The input / output module 106 is included in, for example, the operation units 26, 26a, displays provided in the data transmission devices 2, 2a (not shown), and displays provided in the data receiving device 3a (not shown). Note that the data receiving device 3 does not need to have a configuration for inputting and outputting data, and therefore does not need to have the input / output module 106.

[0117] When the CPU 101 executes an application program pre-stored in the ROM 103 or the auxiliary storage device 104, the database units 20, 30, the timing units 23, 33, the transmitting unit 25, the data transmission speed calculation unit 27, the status change unit 28, the receiving unit 34, the judgment unit 35, and the processing execution unit 36 ​​are configured, and the software parts of the communication interface units 21, 31 and the operation units 26, 26a are configured, and in the RAM 102 or the auxiliary storage device 104, the correspondence table memory units 22, 22a, 32, 32a, the conversion processing status memory unit 24, the memory unit 37, and the internal memory areas of each of the above-mentioned devices and each of the functional units are secured.

[0118] Third Embodiment An embodiment of the present disclosure will be described below with reference to the drawings. As shown in Fig. 13, a data transmission device 200 includes a data transmission rate calculation means 201 that calculates a data transmission rate based on either the communication rate of a communication line or the amount of data to be transmitted, and information indicating a data transmission rate calculation condition, and a transmission means 202 that transmits the transmission data at the data transmission rate through the communication line.

[0119] 14, in the data transmitting device 200, the data transmission rate calculation means 201 calculates the data transmission rate based on either the communication rate of the communication line or the amount of data to be transmitted, and information indicating the data transmission rate calculation conditions (S201). The transmitting means 202 transmits the transmission data through the communication line at the calculated data transmission rate (S202).

[0120] Although the present disclosure has been described above with reference to the embodiments, the present disclosure is not limited to the above-described embodiments. Various modifications that can be understood by those skilled in the art can be made to the configuration and details of the present disclosure within the scope of the present disclosure. Furthermore, each embodiment can be combined with other embodiments as appropriate.

[0121] Some or all of the above-described embodiments can be described as, but are not limited to, the following supplementary notes.

[0122] (Supplementary Note 1) A data transmission device comprising: a data transmission rate calculation means (e.g., a data transmission rate calculation unit 27, a data transmission rate calculation means 201) that calculates a data transmission rate based on either the communication rate of a communication line or the amount of data to be transmitted, and information indicating a data transmission rate calculation condition; and a transmission means (e.g., a transmission unit 25, a transmission means 202) that transmits the transmission data at the data transmission rate through the communication line.

[0123] (Appendix 2) A data transmission device as described in (Appendix 1), wherein the information indicating the data transmission rate calculation conditions when calculating the data transmission rate using the communication rate of the communication line is the rate at which the communication line is used.

[0124] (Appendix 3) A data transmission device as described in (Appendix 1), wherein the information indicating the data transmission rate calculation conditions when calculating the data transmission rate using the data volume of the transmission data is the time allowed for transmitting the transmission data.

[0125] (Supplementary Note 4) The data transmitting device according to (Supplementary Note 3), wherein the data transmission rate calculation means issues an error notification when the data transmission rate exceeds the communication rate of the communication line.

[0126] (Appendix 5) The data transmission device described in any one of (Appendix 1) to (Appendix 4), wherein the transmission means performs the data conversion process on the transmission data and transmits the transmission data when the determination result by a determination means (e.g., a determination unit 35) that determines based on the state of the communication path whether or not to perform a data conversion process for converting a data component included in the transmission data and associated with an element index represented by a data amount smaller than the data amount of the data component into the element index corresponding to the data component indicates that processing is required.

[0127] (Appendix 6) The data transmission device described in (Appendix 5), wherein the transmitting means transmits a transmission time indicating the time to start transmitting the transmission data, and the determining means uses the transmission time and a reception time indicating the time to start receiving the transmission data at the receiving side as the state of the communication path, and determines whether or not to perform the data conversion process based on the reception time, the transmission time, and a predetermined allowable delay time.

[0128] (Supplementary Note 7) A data transmission / reception system comprising a data transmission device and a data receiving device, wherein the data transmission device comprises a data transmission rate calculation means (e.g., data transmission rate calculation unit 27, data transmission rate calculation means 201) that calculates a data transmission rate based on either the communication rate of a communication line or the amount of data to be transmitted, and information indicating a data transmission rate calculation condition, and a transmission means (e.g., transmission unit 25, transmission means 202) that transmits transmission data at the data transmission rate through the communication line, and the data receiving device comprises a receiving means (e.g., reception unit 34) that receives the transmission data.

[0129] (Appendix 8) A data transmission and reception system as described in (Appendix 7), wherein the information indicating the data transmission rate calculation conditions when calculating the data transmission rate using the communication rate of the communication line is the rate at which the communication line is used.

[0130] (Appendix 9) A data transmission and reception system as described in (Appendix 7), wherein the information indicating the data transmission rate calculation conditions when calculating the data transmission rate using the data volume of the transmission data is the time allowed for transmitting the transmission data.

[0131] (Supplementary Note 10) The data transmission / reception system according to (Supplementary Note 9), wherein the data transmission rate calculation means issues an error notification if the data transmission rate exceeds the communication rate of the communication line.

[0132] (Supplementary Note 11) A data transmission and reception system as described in any one of (Supplementary Note 7) to (Supplementary Note 10), wherein the transmitting means, when transmitting the transmission data, performs the data conversion process on the transmission data and transmits the transmission data if the determination result by a determination means (e.g., a determination unit 35) that determines based on the state of the communication path whether or not to perform data conversion processing for converting a data component included in the transmission data and associated with an element index represented by a data amount smaller than the data amount of the data component into the element index corresponding to the data component indicates the need for processing; the data receiving device is equipped with the determination means; and the receiving means receives the transmission data, and when the data conversion processing is being performed in the data transmitting device, replaces the element index included in the received transmission data with the data component corresponding to the element index.

[0133] (Appendix 12) The data transmission and reception system described in (Appendix 11), wherein the transmitting means transmits a transmission time indicating the time to start transmitting the transmission data, the receiving means receives the transmission time and acquires a reception time indicating the time to start receiving the transmission data, and the determining means uses the reception time and the transmission time as the state of the communication path and determines whether or not to perform the data conversion process based on the reception time, the transmission time, and a predetermined allowable delay time.

[0134] (Appendix 13) A data transmission / reception system as described in (Appendix 11) or (Appendix 12), wherein the judgment means causes the data transmission device to start the data conversion process when the judgment result indicates that processing is required and the data conversion process is not being performed in the data transmission device, and causes the data transmission device to stop the data conversion process when the judgment result indicates that processing is not required and the data conversion process is being performed in the data transmission device.

[0135] (Appendix 14) A data transmission method, which calculates a data transmission speed based on either the communication speed of a communication line or the amount of data to be transmitted, and information indicating a data transmission speed calculation condition, and transmits the transmission data at the calculated data transmission speed through the communication line.

[0136] (Appendix 15) A data transmission method as described in (Appendix 14), wherein the information indicating the data transmission rate calculation conditions when calculating the data transmission rate using the communication rate of the communication line is the rate at which the communication line is used.

[0137] (Appendix 16) A data transmission method as described in (Appendix 14), wherein the information indicating the data transmission rate calculation conditions when calculating the data transmission rate using the data volume of the transmission data is the time allowed for transmitting the transmission data.

[0138] (Supplementary Note 17) The data transmission method according to (Supplementary Note 16), wherein an error notification is issued if the calculated data transmission speed exceeds the communication speed of the communication line.

[0139] (Appendix 18) A data transmission method according to any one of (Appendix 14) to (Appendix 17), in which, when the result of a judgment by a judgment means (e.g., judgment unit 35) that judges based on the state of the communication path whether or not to perform a data conversion process for converting a data component included in the transmission data and associated with an element index represented by a data amount smaller than the data amount of the data component into the element index corresponding to the data component indicates that processing is required, the data conversion process is performed on the transmission data before transmitting the transmission data.

[0140] (Appendix 19) A data transmission method as described in (Appendix 18), in which a transmission time indicating the time to start transmitting the transmission data is transmitted, and the determination means uses the transmission time and a reception time indicating the time to start receiving the transmission data at the receiving side as the state of the communication path, and determines whether or not to perform the data conversion process based on the reception time, the transmission time, and a predetermined allowable delay time.

[0141] (Appendix 20) A program for causing a computer to function as a data transmission rate calculation means (e.g., data transmission rate calculation unit 27, data transmission rate calculation means 201) that calculates a data transmission rate based on either the communication rate of a communication line or the amount of data to be transmitted, and information indicating data transmission rate calculation conditions, and a transmission means (e.g., transmission unit 25, transmission means 202) that transmits the transmission data at the data transmission rate through the communication line.

[0142] (Appendix 21) The program described in (Appendix 20), wherein the information indicating the data transmission rate calculation conditions when calculating the data transmission rate using the communication rate of the communication line is the rate at which the communication line is used.

[0143] (Appendix 22) The program described in (Appendix 20), wherein the information indicating the data transmission rate calculation conditions when calculating the data transmission rate using the data volume of the transmission data is the time allowed for transmitting the transmission data.

[0144] (Supplementary Note 23) The program according to (Supplementary Note 22), wherein the data transmission rate calculation means issues an error notification if the data transmission rate exceeds the communication rate of the communication line.

[0145] (Appendix 24) The program described in any one of (Appendix 20) to (Appendix 23), wherein the transmitting means, when transmitting the transmission data, performs the data conversion process on the transmission data and transmits the transmission data if the determination result by a determination means (e.g., a determination unit 35) that determines based on the state of the communication path whether or not to perform a data conversion process for converting a data component included in the transmission data and associated with an element index represented by a data amount smaller than the data amount of the data component into the element index corresponding to the data component indicates that processing is required.

[0146] (Appendix 25) The program described in (Appendix 24), wherein the transmitting means transmits a transmission time indicating the time to start transmitting the transmission data, and the determining means uses the transmission time and a reception time indicating the time to start receiving the transmission data at the receiving side as the state of the communication path, and determines whether or not to perform the data conversion process based on the reception time, the transmission time, and a predetermined allowable delay time.

[0147] (Supplementary Note 26) A data receiving device comprising: a determination means (e.g., a determination unit 35) that determines, based on the state of a communication path, whether or not to cause the transmitting side to perform a data conversion process for converting a data component included in transmission data transmitted from the transmitting side, the data component being associated with an element index represented by a data amount smaller than the data amount of the data component, into the element index corresponding to the data component; and a receiving means (e.g., a receiving unit 34) that receives the transmission data and, if the data conversion process is being performed on the transmitting side, replaces the element index included in the received transmission data with the data component corresponding to the element index.

[0148] (Appendix 27) The receiving means receives a transmission time indicating the time to start transmitting the transmission data sent from the transmitting side, and obtains a reception time indicating the time to start receiving the transmission data, and the determination means uses the reception time and the transmission time as the state of the communication path, and determines whether to perform the data conversion process based on the reception time, the transmission time, and a predetermined allowable delay time. (Appendix 26) A data receiving device as described in

[0149] (Appendix 28) A data receiving device as described in (Appendix 26) or (Appendix 27), wherein the judgment means causes the transmitting side to start the data conversion process if the judgment result indicates that processing is required and the data conversion process is not being performed on the transmitting side, and causes the transmitting side to stop the data conversion process if the judgment result indicates that processing is not required and the data conversion process is being performed on the transmitting side.

[0150] (Supplementary Note 29) A data receiving method comprising: determining, based on a state of a communication path, whether or not to have the transmitting side perform a data conversion process to convert a data component included in transmission data sent from the transmitting side, the data component being associated with an element index represented by a data amount smaller than the data amount of the data component, into the element index corresponding to the data component; receiving the transmission data; and, if the data conversion process is being performed on the transmitting side, replacing the element index included in the received transmission data with the data component corresponding to the element index.

[0151] (Appendix 30) A data receiving method as described in (Appendix 29), which receives a transmission time indicating the time to start transmitting the transmission data from the transmitting side, obtains a reception time indicating the time to start receiving the transmission data, uses the reception time and the transmission time as the state of the communication path, and determines whether or not to perform the data conversion process based on the reception time, the transmission time, and a predetermined allowable delay time.

[0152] (Appendix 31) A data receiving method according to (Appendix 29) or (Appendix 30), in which, if the judgment result indicates that processing is required and the data conversion processing is not being performed on the transmitting side, the transmitting side is made to start the data conversion processing, and, if the judgment result indicates that processing is not required and the data conversion processing is being performed on the transmitting side, the transmitting side is made to stop the data conversion processing.

[0153] (Appendix 32) A program for causing a computer to function as a determination means (e.g., a determination unit 35) that determines, based on the state of a communication path, whether or not to cause the sending side to perform a data conversion process for converting a data component included in transmission data sent from the sending side, which data component is associated with an element index represented by a data amount smaller than the data amount of the data component, into the element index corresponding to the data component, and a receiving means (e.g., a receiving unit 34) that receives the transmission data and, if the data conversion process is being performed on the sending side, replaces the element index included in the received transmission data with the data component corresponding to the element index.

[0154] (Appendix 33) The program described in (Appendix 32), wherein the receiving means receives a transmission time indicating the time to start transmitting the transmission data from the transmitting side, and obtains a reception time indicating the time to start receiving the transmission data, and the determining means uses the reception time and the transmission time as the state of the communication path, and determines whether to perform the data conversion process based on the reception time, the transmission time, and a predetermined allowable delay time.

[0155] (Appendix 34) The program described in (Appendix 32) or (Appendix 33), wherein the judgment means, if the judgment result indicates that processing is required and the data conversion processing is not being performed on the sending side, causes the sending side to start the data conversion processing, and if the judgment result indicates that processing is not required and the data conversion processing is being performed on the sending side, causes the sending side to stop the data conversion processing. [Explanation of symbols]

[0156] 1. Data transmission and reception system 2 Data transmission device 3 Data receiving device 4. Communication Network 5-1 Communication lines 5-2 Communication lines 20 Database Department 21 Communication interface section 22 Correspondence table storage unit 23 Timing section 24 Conversion processing status memory unit 25 Transmitter 26 Control section 27 Data transmission speed calculation section 28 State change section 30 Database Department 31 Communication interface section 32 Correspondence table storage unit 33 Timing section 34 Receiving unit 35 Judgment section

Claims

1. a data transmission rate calculation means for calculating a data transmission rate based on either one of the communication rate of the communication line and the amount of data to be transmitted, and information indicating a data transmission rate calculation condition; a transmitting means for transmitting the transmission data at the data transmission rate through the communication line; A data transmission device comprising:

2. When the data transmission rate is calculated using the communication rate of the communication line, the information indicating the data transmission rate calculation condition is a rate at which the communication line is used.

2. The data transmission device according to claim 1.

3. The information indicating the data transmission rate calculation condition when the data transmission rate is calculated using the data amount of the transmission data is an allowable time required to transmit the transmission data.

2. The data transmission device according to claim 1.

4. The data transmission rate calculation means If the data transmission speed exceeds the communication speed of the communication line, an error notification is issued.

4. The data transmission device according to claim 3.

5. The transmitting means a determining means for determining whether or not to perform a data conversion process for converting a data component included in the transmission data and associated with an element index represented by a data amount smaller than the data amount of the data component into the element index corresponding to the data component based on a state of a communication path, when the determination result indicates the need for the process, performing the data conversion process on the transmission data before transmitting the transmission data; 5. The data transmission device according to claim 1.

6. the transmitting means transmits a transmission time indicating a time to start transmitting the transmission data; The determination means a reception time indicating the time when the receiving side starts receiving the transmission data and the transmission time are used as the state of the communication path, and a determination is made as to whether or not to perform the data conversion process based on the reception time, the transmission time, and a predetermined allowable delay time.

6. The data transmission device according to claim 5.

7. A data transmitting device and a data receiving device are provided, The data transmission device a data transmission rate calculation means for calculating a data transmission rate based on either one of the communication rate of the communication line and the amount of data to be transmitted, and information indicating a data transmission rate calculation condition; a transmitting means for transmitting transmission data at the data transmission rate through the communication line; Equipped with The data receiving device receiving means for receiving the transmission data A data transmission and reception system comprising:

8. The transmitting means a determination means for determining whether or not to perform a data conversion process for converting a data component included in the transmission data and associated with an element index represented by a data amount smaller than the data amount of the data component into the element index corresponding to the data component based on a state of a communication path, when the determination result indicates the need for the process, performing the data conversion process on the transmission data when transmitting the transmission data; The data receiving device The determination means is provided, The receiving means receiving the transmission data, and if the data conversion process is being performed in the data transmission device, replacing the element index included in the received transmission data with the data component corresponding to the element index; 8. The data transmission and reception system according to claim 7.

9. Calculating a data transmission speed based on either the communication speed of the communication line or the amount of data to be transmitted, and information indicating a data transmission speed calculation condition; transmitting the transmission data through the communication line at the calculated data transmission speed; Data transmission method.

10. Computer, a data transmission rate calculation means for calculating a data transmission rate based on either one of the communication rate of the communication line and the amount of data to be transmitted, and information indicating a data transmission rate calculation condition; a transmitting means for transmitting the transmission data at the data transmission rate through the communication line; A program to function as a

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