WO2016147650A1

WO2016147650A1 - Transmitting apparatus and control method therefor, communication system, and recording medium storing communication control program

Info

Publication number: WO2016147650A1
Application number: PCT/JP2016/001451
Authority: WO
Inventors: 由明西川
Original assignee: 日本電気株式会社
Priority date: 2015-03-19
Filing date: 2016-03-15
Publication date: 2016-09-22
Also published as: JPWO2016147650A1; JP6863274B2

Abstract

A transmitting apparatus transmits data on a continual basis without waiting for ACK data. A transmission-side apparatus 81 transmits data to be transmitted to a receiving-side apparatus 41, and is provided with: a transmission-side transmitting-receiving unit 82 that receives, from the receiving-side apparatus 41, an acknowledgment corresponding to the transmitted data; a transmission stop monitoring unit 83 that confirms whether transmission of data to be transmitted is stopped at the transmission-side transmitting-receiving unit 82; and a transmission continuation unit 84 that continues, in the case where it is determined by the transmission stop monitoring unit that transmission of the data to be transmitted by the transmission-side transmitting-receiving unit is stopped, transmission of the data to be transmitted instead of the transmission-side transmitting-receiving unit.

Description

Transmitting apparatus, control method therefor, communication system, and recording medium storing communication control program

The present invention relates to a transmission device, a control method thereof, a communication system, and a recording medium storing a communication control program.

When the receiving terminal receives the data packet transmitted from the transmitting terminal to the receiving terminal, the receiving terminal transmits an acknowledgment (hereinafter referred to as “ACK”) packet to the transmitting terminal. When receiving the ACK packet, the transmitting terminal transmits the next data packet to the receiving terminal. Communication systems that perform such operations are known.

As a communication method of a communication network (hereinafter simply referred to as “network”) in which the transmitting terminal and the receiving terminal are communicably connected, for example, a general TCP (Transmission_Control_Protocol) protocol (hereinafter “TCP”) is used today. For short).

In TCP, for example, transmission by a transmitting terminal is performed so that congestion (a situation in which a transmitted data packet is delayed or lost due to inflow of data exceeding the transmission capacity of the network) into the network does not occur. In the buffer, the transmission amount of the data packet is limited by using a window indicating data that can be transmitted at a time without receiving the ACK packet.

As an example, a window in TCP will be described with reference to FIG. FIG. 9 is a diagram conceptually illustrating windows used in the transmission buffer.

The item (1) shown in FIG. 9 shows the contents of the transmission buffer before a new data packet is written. In the acknowledged response area (shaded area), the receiving terminal transmits an ACK packet corresponding to the data packet transmitted up to the hatched part to the transmitting terminal, and the transmitting terminal receives the ACK packet. Show.

When the transmitting terminal receives the ACK packet, it erases the transmitted data packet stored in the transmission buffer until then (shaded area). The transmitting terminal then acknowledges the upper limit position of the area where the deleted transmitted data packet is stored up to the data packet at that position (ACK (1) shown in FIG. 9). Use the up arrow)

(2) indicates a transmittable area and a transmission waiting area following the confirmation response area. In the transmittable area and the transmission waiting area, data packets a to n written in the transmission buffer by the transmitting terminal are stored.

In the transmittable area, data packets a to e within the range of data amount that can be transmitted at a time without receiving an ACK packet (that is, window size) are stored (see FIG. 5). In the example of 9, the window size is “5”.)

In the following, the window size is also referred to as “transmission amount limit range”.

The transmission waiting area indicates data packets f to n transmitted after the data packets a to e among the data packets a to n written in the transmission buffer.

When the transmitting terminal transmits the data packets a to e to the receiving terminal, the transmitted pointer indicating that the data packet e has been transmitted up to the position of the data packet e (the left side of the item (2) in FIG. 9). The second upward arrow).

At this point, each of the data packets a to e is a data packet that has been transmitted and is waiting for an ACK.

Item (3) indicates that the receiving terminal has received, for example, only data packet a among data packets a to e.

When the transmitting terminal receives the ACK packet from the receiving terminal corresponding to the data packet a, the transmitting terminal deletes the data packet a stored in the transmission buffer until then (the second one from the left in the item (3) shown in FIG. 9). (Hatched area). Then, the transmitting terminal indicates the position where the data packet a is located with an ACKed pointer indicating that the data packet a has been ACKed (first from the left in the item (3) shown in FIG. 9). Up arrow).

At this point, each of the data packets b to e is a data packet that has been transmitted and is waiting for an ACK (a range indicated by a double arrow A in (3) in FIG. 9).

The term (3) also indicates that the window is shifted to the right by the amount of the data packet a erased by the transmitting terminal (that is, the range indicated by the double arrow B in the term (3) shown in FIG. 9). By shifting one window to the right of the ACK-waiting data packets b to e that have been transmitted, the data packet f becomes the data packet to be transmitted next.

In the following, when the window is shifted to the right side, there is room for the next transmitted data to enter the transmittable area.

The transmission buffer transmits the next data packet f to the receiving terminal, and indicates the position of the data packet f with a transmitted pointer indicating that the data packet f has already been transmitted (shown in FIG. 9). 3) Second upward arrow from the left of item).

That is, when the transmitting terminal can receive the ACK packet corresponding to the transmitted data packet a, the size “4” of the transmitted data packets b to e indicated by A and indicated by B is indicated by B. Since the window size is smaller than “5”, there is a free space in which data packet f waiting for transmission can enter in the transmittable area.

When there is a vacant space in the transmittable area, the transmitting terminal transmits the transmission waiting data packet f in the transmission buffer, assuming that the transmission amount limit is not reached.

The item (4) is the item (3), and when the transmitting terminal cannot receive the ACK packet corresponding to the data packet a due to a change in the communication environment, the data packet a that cannot be acknowledged cannot be deleted. Indicates that the minutes window cannot slide to the right.

Therefore, in the item (4), the size “5” indicated by A of the data packets a to e that have been transmitted by the transmitting terminal and are waiting for ACK becomes equal to or larger than the window size “5” indicated by B, and is set in the transmittable area. There is no room for data packets waiting to be sent.

When there is no space in the transmittable area, the transmitting terminal stops transmitting the next transmission-waiting data packet f in the transmission buffer, assuming that the transmission amount limit has been reached.

In general TCP, if a transmitting terminal cannot receive an ACK packet corresponding to a transmitted data packet within a predetermined time, the transmitted data packet is retransmitted every predetermined retransmission waiting time.

When the above-described transmission terminal and reception terminal are respectively a server terminal and a mobile terminal on the Web on the Internet, for example, there is a mobile network on the way.

In such a mobile network, movement of a mobile terminal, a decrease in radio field intensity due to a handover in which the mobile terminal switches wireless connection with a plurality of base stations, congestion in a base station due to a large number of mobile terminals being connected, etc. The communication environment unique to the mobile environment will change.

Due to the above-described fluctuations in the communication environment, the base station and the mobile terminal may lose data packets from the base station to the mobile terminal (downward), or may be The ACK packet to the station (upward direction) may be lost.

If at least one of the data packet and the ACK packet described above is lost in the network, as a result, the ACK packet is not received by the server terminal on the Web. Therefore, no new space is generated in the window in the transmission buffer of the server terminal on the Web.

Therefore, the data packet that has been transmitted in the transmission buffer and is waiting for ACK reaches the limit of the transmission amount, and the transmission of the data packet waiting to be transmitted next in the transmission buffer is stopped.

After that, even if the communication environment between the base station and the mobile terminal is restored to a communicable state, the server terminal on the Web does not receive the ACK packet from the mobile terminal until the data packet to the mobile terminal is received. Stop sending.

For example, as a related technique, Patent Document 1 discloses the following technique. That is, when the client 10 returns an ACK message to the server 12, the client 10 starts measuring a timer that measures a predetermined time T1. When the next data packet from the server 12 is not received by the client 10 after the timer counts a predetermined time, the client 10 detects that the physical transmission medium is interrupted, and repeats the same ACK message. 12 to send.

Patent Document 2 discloses the following technique. That is, when it is detected that the radio link between the ground station 3 (transmitting terminal) and the mobile station 4 (receiving terminal) has recovered from the disconnected state, it is stored in the ACK packet storage means that stores the ACK packet at the receiving terminal. The latest ACK packet is transmitted to the transmitting terminal. As a result, the transmitting terminal determines a data packet to be retransmitted based on the transmitted ACK packet.

Patent Document 3 discloses the following technique. That is, when the receiving device 200 receives a packet transmitted from the transmitting device 100 and an error is detected in the received packet, the detected error is corrected. Then, even if the receiving apparatus 200 cannot correct the error within a predetermined time, the transmitting apparatus 100 continues the correction, and returns the acknowledgment ACK when the correction is correct. Are continuously transmitted in a maximum of N ranges. As a result, the transmission frequency of retransmission packets from the transmission apparatus 100 to the reception apparatus 200 is suppressed.

Patent Document 4 discloses the following technique. That is, in a system that broadcasts transmission data packets from the wireless access point 1 to a plurality of receiving terminals, when the ACK signal from the receiving terminal is not received at the access point 1, the accumulated amount of data before transmission at the access point 1 is If the specified size is exceeded, retransmission of the transmitted data packet is stopped. As a result, the system eliminates the transmission delay of the data packet.

In Patent Document 5, when the retransmission grasp unit 214 of the relay apparatus 120 that receives a packet transmitted from the base station 130 detects a missing number of the sequence number of the received packet, the relay apparatus 120 transmits a retransmission of the missing packet to the base station. Techniques required for 130 are disclosed.

Patent Document 5 discloses the following technology. That is, when the no-communication detection unit 220 detects a no-communication state that occurs when the relay device 120 receives a packet retransmitted by the base station 130 based on a request from the relay device 120, The dummy data is transmitted to the base station 130 by 216 so that the channel between the base station 130 and the relay apparatus 120 is not released.

Patent Document 6 discloses the following technique. In other words, the technology transmits an ARP packet in a first period for confirming the normality of the counterpart device from either one of the packet communication devices 1 and 2 that transmit and receive data via the communication network 10. If no response to the ARP packet is received, it is determined that the counterpart device is in an abnormal state. And the technique suppresses that traffic increases by stopping transmission of the data to the said counterpart apparatus after that.

Japanese Patent No. 5185955 Japanese Patent No. 4832483 JP 2008-079350 A JP 2006-324738 A JP 2010-069442 A JP 2008-018417 A

However, when data packets and / or ACK messages are lost due to changes in the communication environment, in general TCP, data packets cannot be transmitted unless the transmitting terminal waits for the maximum waiting time for data packet retransmission. .

Also, with the technique described in Patent Document 1, data packets cannot be transmitted unless the server 12 waits for a maximum T1 time of an ACK packet repetitive transmission interval.

That is, in the general TCP and Patent Document 1 described above, there is a problem in that communication efficiency as a communication system is reduced because a delay corresponding to the above-described data packet and ACK packet occurs in the transmission terminal.

In each of the related Patent Documents 2 to 6, there is no description that the transmitting terminal transmits the next data packet without waiting for the ACK packet and without retransmitting the transmitted data packet. .

An object of the present invention is to provide a communication system, a communication control method, and a communication control program that solve the above-described problems.

In one aspect of the present invention, the transmission device transmits the transmission target data to the reception device, and transmits a confirmation response corresponding to the transmission target data from the reception device, and the transmission side transmission / reception unit. Transmission stop monitoring means for confirming whether or not transmission of the transmission target data is stopped, and when the transmission stop monitoring means determines that transmission of the transmission target data by the transmission side transmission / reception means is stopped And transmission continuation means for continuing transmission of the transmission target data in place of the transmission side transmission / reception means.

In another aspect of the present invention, a method for controlling a transmission device includes: transmission side transmission / reception means for transmitting transmission target data to a reception device and receiving an acknowledgment corresponding to the transmission target data from the reception device; A transmission stop monitoring means for confirming whether transmission of the transmission target data in the transmission side transmission / reception means is stopped; a transmission continuation means for transmitting the transmission target data based on an instruction from the transmission stop monitoring means; A transmission apparatus control method comprising: when the transmission stop monitoring means determines that transmission of the transmission target data of the transmission side transmission / reception means has been stopped, the transmission side transmission / reception means transmits the transmission target data. The transmission continuation means is controlled to continue in place of the means.

In another aspect of the present invention, a communication system includes:
A transmission apparatus capable of transmitting transmission target data and a reception apparatus connected via a communication network capable of communicating with the transmission apparatus and capable of returning an acknowledgment when the transmission target data is received from the transmission apparatus The transmission device transmits the transmission target data to the reception device, and transmits and receives the confirmation response corresponding to the transmission target data from the reception device, and the transmission side transmission / reception. A transmission stop monitoring means for confirming whether or not transmission of the transmission target data in the means is stopped, and a case where the transmission stop monitoring means determines that transmission of the transmission target data by the transmission side transmission / reception means is stopped The transmission continuation unit continues the transmission of the transmission target data in place of the transmission side transmission / reception unit.

Furthermore, the present invention is also realized by a transmission control program or a recording medium (storage medium) storing the transmission control program corresponding to the transmission apparatus having the above-described configuration or its control method.

The present invention has an effect of suppressing the delay for the time waiting for data or ACK data and improving the communication efficiency as a communication system.

It is a block diagram which shows the 1st Embodiment of this invention. It is a flowchart which shows the flow of a process of the transmission side apparatus in 1st Embodiment. It is a block diagram which shows the 2nd Embodiment of this invention. It is a flowchart which shows the flow of a process of the transmission side apparatus in 2nd Embodiment. It is a block diagram which shows the 3rd Embodiment of this invention. It is a block diagram which shows the 3rd Embodiment of this invention. It is a flowchart which shows the flow of a process of the transmission side apparatus in 3rd Embodiment. It is a figure which illustrates illustartively the structure of the information processing apparatus (computer) which can perform the transmission side apparatus in exemplary embodiment of this invention. It is a figure which illustrates notionally the window used with a transmission buffer.

Next, embodiments of the present invention will be described in detail with reference to the drawings.

<First Embodiment>
First, the first embodiment will be described. FIG. 1 is a block diagram showing the first embodiment.

Referring to FIG. 1, a communication system 1 according to the present embodiment includes a transmission-side device 11 and a reception-side device 31 connected via a network that can communicate with the transmission-side device 11.

The transmission side device 11 includes a transmission side transmission / reception unit 12, a transmission stop monitoring unit 13, a transmission continuation unit 14, and a shared transmission / reception unit 19. The reception side device 31 includes a reception side transmission / reception unit 32.

The transmission side transmission / reception unit 12 includes a transmission buffer 20.

The transmission continuation unit 14 includes a transmission buffer (not shown in FIG. 1).

The shared transmission / reception unit 19 includes a transmission buffer (not shown in FIG. 1).

The reception side transmission / reception unit 32 of the reception side device 31 includes a transmission buffer (not shown in FIG. 1).

When the data from the transmission buffer 20 or the transmission buffer of the transmission continuation unit 14 is written (copied) to the transmission buffer of the shared transmission / reception unit 19, the shared transmission / reception unit 19 sends the written data to the reception-side device 31. Send.

The shared transmission / reception unit 19 receives ACK data from the reception side device 31 and passes it to the transmission side transmission / reception unit 12.

The transmission stop monitoring unit 13 and the transmission continuation unit 14 will be described in the operation description in the present embodiment to be described later.

The transmission buffer 20 is a storage area for storing write data from the transmission side device 11.

Next, the operation of this embodiment will be described with reference to FIG.

FIG. 2 is a diagram illustrating a processing flow of the transmission-side apparatus 11 in the present embodiment.

When the transmission side device 11 writes data in the transmission buffer 20, the transmission buffer 20 transmits data of the amount of data that can be transmitted at a time without receiving ACK data among the written data. Is transmitted to the receiving terminal 31 (step S51).

The transmission stop monitoring unit 13 checks whether transmission of data written in the transmission buffer 20 from the transmission buffer 20 has been stopped (step S52).

In step S52, the transmission stop monitoring unit 13 determines that the transmission buffer 20 has not stopped data transmission when the transmission side device 11 has received ACK data from the reception side device 31 (step S52). NO).

That is, the transmission stop monitoring unit 13 determines that the size of the data that has been transmitted and is waiting for ACK is smaller than the window size and that there is a free window, “size of transmitted and ACK waiting data− (minus) window size <0 When the condition of “” is satisfied, it is determined that the transmission buffer 20 has not stopped data transmission because the transmission amount limit is not reached.

Note that the above-described determination method is an example, and is not limited to the above-described method.

If the transmission buffer 20 is NO in step S52, the transmission buffer 20 executes processing for transmitting the data shown in step S51.

On the other hand, in step S52, the transmission stop monitoring unit 13 determines that the transmission buffer 20 has stopped transmitting data when the transmission side device 11 cannot receive ACK data from the reception side device 31 (step S52). In S52, YES).

That is, the transmission stop monitoring unit 13 satisfies the condition of “the size of the transmitted and ACK waiting data−the window size ≧ 0” in which the size of the data that has been transmitted and is waiting for the ACK is equal to or larger than the window size and the window is not empty. If so, do the following: That is, the transmission stop monitoring unit 13 determines that the transmission buffer 20 has stopped transmitting data because the transmission buffer has reached the limit of the transmission amount.

If the transmission continuation unit 14 is YES in step S52, the transmission continuation unit 14 performs a process of step S53 described later.

That is, the transmission stop monitoring unit 13 instructs the transmission continuation unit 14 to take the data that the transmission buffer 20 was scheduled to transmit next from the transmission buffer 20 to the transmission buffer of the transmission continuation unit 14.

The transmission continuation unit 14 writes the data of the transmission buffer 20 taken by the transmission continuation unit 14 in the transmission buffer of the shared transmission / reception unit 19.

The shared transmitting / receiving unit 19 transmits the data written from the transmission buffer of the transmission continuation unit 14 to the reception side device 31 (step S53).

In step S52, the transmission stop monitoring unit 13 determines that the transmission side device 11 cannot receive the ACK data from the reception side device 31 and the transmission buffer 20 has stopped transmitting data. It is confirmed whether or not the stop of transmission of data from 20 is released (step S54).

The transmission stop monitoring unit 13 determines that the stop of data transmission in the transmission buffer 20 has not been canceled when the transmission side device 11 cannot receive the ACK data from the reception side device 31 in step S54 (in step S54). , NO).

That is, the transmission stop monitoring unit 13 determines that the size of the data that has been transmitted and is waiting for ACK is equal to or larger than the window size, the window is not free, and has reached the limit of the transmission amount. It is determined that the stop of the transmission is not released.

In step S54, the transmission continuation unit 14 executes the process shown in step S53 described above in the case of NO.

On the other hand, in step S54, the transmission stop monitoring unit 13 determines that the stop of data transmission in the transmission buffer 20 is released when the transmission side device 11 can receive ACK data from the reception side device 31 (step S54). In S54, YES).

In other words, the transmission stop monitoring unit 13 has already transmitted and the size of the data waiting for ACK is smaller than the window size, the window is vacant, and the transmission amount limit is not reached. It is determined that the transmission stop has been released.

The transmission buffer 20 resumes the process of transmitting the data shown in step S51 described above when YES in step S54.

At that time, the transmission continuation unit 14 stops data transmission by the transmission buffer of the transmission continuation unit 14.

In this way, the transmission side device 11 can continue the data transmission using the transmission continuation unit 14 even if the ACK data from the reception side device 31 is not received.

Note that, in step S54, the following method may be employed as another method for determining that the stop of transmission of data from the transmission buffer 20 is released. In other words, the transmission stop monitoring unit 13 may determine that the stop of data transmission has been released by the transmission buffer 20 restarting the data transmission process shown in step S51 described above.

Moreover, if the shared transmission / reception part 19 can transmit the data of the transmission buffer of the transmission buffer 20 or the transmission continuation part 14 to the reception side apparatus 31, and can pass the ACK data from the reception side apparatus 31 to the transmission side transmission / reception part 12. The method is not limited to the method described above, and other methods may be used.

As described above, this embodiment has the effect of suppressing the delay for the time waiting for data or ACK data and improving the communication efficiency as the communication system.

The reason is that the transmission continuation unit 14 is provided in the transmission side device 11 so as to continuously transmit data without waiting for ACK data.

Further, when the above-described transmission-side device and reception-side device are applied to a mobile communication environment as a server terminal and a mobile terminal on the Web, which are external terminals of the base station, for example, the following effects are also obtained. In other words, it is not necessary to modify the mobile terminal that is an unspecified number of receiving side devices, and it is applied only to the server terminal on the Web that is a common transmitting side device so that the processing shown in FIG. 2 can be executed. Therefore, the introduction cost can be reduced.

<Second Embodiment>
Next, a second embodiment will be described. FIG. 3 is a block diagram showing the second embodiment.

Referring to FIG. 3, the communication system 70 of the present embodiment includes a transmission-side device 71 and a reception-side device 31 connected via a network that can communicate with the transmission-side device 71.

The transmission side device 71 in this embodiment is different from the configuration of the first embodiment in that an ACK history storage unit 76 is added to the configuration of the transmission side device 11 described in the first embodiment.

Hereinafter, the configuration and operation different from those of the first embodiment will be mainly described, and the same reference numerals are given to the same components as those of the first embodiment, and the description thereof will be omitted.

The transmission side device 71 includes a transmission side transmission / reception unit 72, a transmission stop monitoring unit 73, a transmission continuation unit 74, a shared transmission / reception unit 79, and an ACK history storage unit 76.

The transmission side transmission / reception unit 72 includes a transmission buffer 80.

The transmission continuation unit 74 includes a transmission buffer (not shown in FIG. 3).

The ACK history storage unit 76 stores information on the reception interval of ACK data each time the transmission side transmission / reception unit 72 receives ACK data from the reception side device 31.

ACK data reception interval information can use, for example, the time value of the communication system and the number of clocks.

Next, the operation of this embodiment will be described with reference to FIG.

FIG. 4 is a diagram illustrating a processing flow of the transmission-side device 71 in the present embodiment.

When the transmission-side device 71 writes data to the transmission buffer 80, the transmission buffer 80 transmits data of the amount of data that can be transmitted at a time without receiving ACK among the written data to the shared transmission / reception unit 79. To the receiving side terminal 31 (step S151).

The transmission stop monitoring unit 73 checks whether transmission of data written in the transmission buffer 80 from the transmission buffer 80 is stopped (step S152).

In step S152, the transmission stop monitoring unit 73 determines that the transmission buffer 80 has not stopped data transmission when the transmission side device 71 has received ACK data from the reception side device 31 (step S152). NO).

That is, the transmission stop monitoring unit 73 satisfies the condition “the size of the transmitted and ACK waiting data−the window size <0”, where the size of the data that has already been transmitted and the ACK waiting is smaller than the window size and there is an empty window. If the above is satisfied, the following processing is performed. That is, the transmission stop monitoring unit 73 determines that the transmission buffer 80 has not stopped data transmission because the transmission buffer has not reached the transmission amount limit range.

If the transmission buffer 80 is NO in step S152, the transmission buffer 80 executes processing for transmitting the data shown in step S151 described above.

On the other hand, in step S152, the transmission stop monitoring unit 73 determines that the transmission buffer 80 has stopped transmitting data when the transmission side device 71 cannot receive ACK data from the reception side device 31 (step S152). In S152, YES).

That is, the transmission stop monitoring unit 73 satisfies the condition of “the size of the transmitted and ACK waiting data−the window size ≧ 0”, in which the size of the transmitted data and the ACK waiting data is equal to or larger than the window size and the window is not empty. In this case, the following processing is performed. That is, the transmission stop monitoring unit 73 determines that the transmission buffer 80 has stopped transmitting data because the transmission buffer has reached the limit of the transmission amount.

In step S152, the transmission continuation unit 74 executes a process of step S153 described later in the case of YES.

The transmission stop monitoring unit 73 instructs the transmission continuation unit 74 to refer to the history of the ACK data reception interval of the ACK history storage unit 76 via the ACK history storage unit 76 (step S153).

The transmission continuation unit 74 refers to the history of the ACK history storage unit 76, and when the transmission side transmission / reception unit 72 continuously receives ACK data at the reception interval of the ACK data stored in the ACK history storage unit 76, Find the amount of data that can be sent.

At this time, the amount of data that can be transmitted by the transmission continuation unit 74 is, for example, as follows. That is, for example, when the maximum segment size of transmission data in TCP is 1500 bytes (12000 bits), and the transmission side device receives ACK data corresponding to the maximum segment size data from the reception side device every second, 12000 bits per second.

The transmission continuation unit 74 takes over the data that the transmission buffer 80 was scheduled to transmit to the transmission buffer of the transmission continuation unit 74 based on the obtained data amount.

The transmission continuation unit 74 writes the data received from the transmission buffer 80 in the transmission buffer of the shared transmission / reception unit 79.

The shared transmission / reception unit 79 transmits the data written from the transmission continuation unit 74 to the reception-side device 31 (step S154).

If the transmission stop monitoring unit 73 determines in step S152 that the transmission of data from the transmission buffer 80 is not stopped (NO in step S152), the transmission stop monitoring unit 73 executes the process shown in step S151.

In step 152, when the transmission side device 71 confirms the stop of data transmission by the transmission buffer 80 and continuously transmits the data by the transmission continuation unit 74, any one of 1) to 7) shown below, Alternatively, control combining these may be performed.

That is,
1) The amount of data when the transmission continuation unit 74 continuously transmits data may exceed the amount of data that can be transmitted by the transmission buffer 80.

2) The transmission rate when the transmission continuation unit 74 continuously transmits data may be a fixed rate or a variable rate. In the case of a variable rate, transmission is performed so that the transmission amount per unit time decreases. Also good.

3) The total transmission amount when data is continuously transmitted by the transmission continuation unit 74 is a relay device (for example, a base station with a mobile terminal) not shown in FIG. 3 that relays downlink data in the network. The transmission buffer may be adjusted so as not to exceed a known buffer amount in the transmission buffer or a buffer amount that is a real multiple of the known buffer amount.

4) As a known buffer amount of a transmission buffer such as a relay device in the network described in the above item 3), a transmission amount limit value used when data is lost due to a change in the communication environment in the past, Window size may be used.

Note that the transmission continuation unit 74 acquires the buffer amount of the relay device by, for example, estimating information by transmitting a large amount of data in advance or information notified in advance when the transmission-side device 71 operates the network. Can do.

5) The transmission continuation unit 74 uses the transmission side transmission / reception unit 72 to transmit dummy ACK data generated by the transmission side device 71 or a relay device that relays uplink reception data in the network when continuously transmitting data. You may make it receive.

Further, the transmission continuation unit 74 may perform processing assuming that ACK data is received as internal processing of the transmission side device 71 when data is continuously transmitted.

6) The transmission side device 71 may relax the range of transmission amount restriction in the transmission buffer 80.

7) When the transmission continuation unit 74 described above continuously transmits data based on the reception rate of ACK data, the transmission-side device 71 can communicate from a state in which the upstream direction cannot be communicated due to a change in the communication environment. When returning to the correct state, the following processing may be executed. That is, when the transmission side device 71 receives the ACK data transmitted from the reception side device 31, the transmission side device 71 includes all of various kinds of information indicating setting values and internal states described later of the transmission side device 71 or Some may be changed.

Alternatively, the transmission side device 71 may return a setting value and an internal state, which will be described later, of the transmission side device 71 to a state before the transmission side device 71 no longer receives ACK data.

For example, in the case of TCP, the setting value and the internal state in the transmission side device 71 shown in the above item 7) are the setting values such as a generally known congestion window (cwnd), slow start threshold (slow_start_threshold; ssthresh), and the like. It is an internal state such as a slow start phase or a congestion avoidance phase, and is various types of information related to a transmission amount limit and a process for adjusting the limit.

However, the various values indicating the setting value and the internal state of the transmission side device 71 are not limited to the above-described values and information.

In step S152 described above, the transmission stop monitoring unit 73 determines that the transmission buffer 80 has stopped transmitting data when the size of the transmitted data in the transmission buffer 80 and the ACK waiting data reaches the transmission amount limit range. It was explained with an example of judgment.

However, the transmission stop monitoring unit 73 stops the data transmission when the transmission buffer 80 satisfies at least one of the following conditions a), b), or c) other than the above-described stop determination conditions. You may make it judge.

That is,
a) The case where the size of the transmitted and ACK waiting data in the transmission buffer 80 reaches the limit of the transmission amount, and the data transmission interval in the transmission side apparatus 71 is delayed by a threshold value or more based on the RTT value.

B) The case where the size of the transmitted ACK waiting data in the transmission buffer 80 reaches the limit of the transmission amount, and the reception interval of the ACK data in the transmission side transmission / reception unit 72 is equal to or greater than a predetermined threshold.

c) When the size of the transmitted and ACK waiting data in the transmission buffer 80 reaches the transmission amount limit range, and the data transmission interval in the transmission side device 71 is delayed by a threshold value based on the RTT value, and When the reception interval of the ACK data in the transmitting side transmission / reception unit 72 becomes equal to or greater than a predetermined threshold.

Here, RTT is an abbreviation for Round_Trip_Time. The RTT receives the transmitted data from the time when the data is transmitted from the transmission side device 71 to the reception side device 31 shown in FIG. 3, and the reception side device 31 acknowledges the received data. This is the observed round-trip delay time between the transmitting side device and the receiving side device until the time when the resulting ACK data is sent to the transmitting side device 71 and the transmitted side device 71 receives the transmitted ACK data. .

The threshold based on the RTT value described above is set to a value such as a real number multiple of the RTT value, for example.

Subsequently, the processing flow of the transmission side apparatus 71 shown in FIG. 4 will be described.

In step S152, the transmission stop monitoring unit 73 determines that the transmission side device 71 cannot receive the ACK data from the reception side device 31 and the transmission buffer 80 has stopped transmitting data. It is confirmed whether or not the stop of transmission of data from 80 is released (step S155).

In step S155, the transmission stop monitoring unit 73 determines that the stop of data transmission in the transmission buffer 80 has not been released when the transmission side device 71 cannot receive the ACK data from the reception side device 31 (step S155). NO).

That is, the transmission stop monitoring unit 73 satisfies the condition “size of transmitted and ACK waiting data−window size ≧ 0” in which the size of the data already transmitted and waiting for ACK is equal to or larger than the window size and there is no space in the window. When the condition is satisfied, since the transmission amount limit is reached, it is determined that the stop of data transmission in the transmission buffer 80 has not been released.

If the transmission continuation unit 74 is NO in step S155, the transmission continuation unit 74 performs the ACK reception rate continuous transmission process shown in step S154 described above.

On the other hand, in step S155, the transmission stop monitoring unit 73 determines that the stop of data transmission in the transmission buffer 80 has been released when the transmission side device 71 has received ACK data from the reception side device 31 (step S155). In S155, YES).

That is, the transmission stop monitoring unit 73 satisfies the condition “the size of the transmitted and ACK waiting data−the window size <0”, where the size of the data that has already been transmitted and the ACK waiting is smaller than the window size and there is an empty window. If the above is satisfied, the following processing is performed. That is, since the transmission amount limit has not been reached, the transmission stop monitoring unit 73 determines that the stop of data transmission in the transmission buffer 80 has been released.

When the transmission buffer 80 is YES in step S155, the transmission buffer 80 resumes the data transmission process shown in step S151 described above.

At that time, the transmission continuation unit 74 stops data transmission by the transmission buffer of the transmission continuation unit 74.

As described above, in this embodiment, in addition to the effects of the first embodiment, there is an effect that the load on the network can be reduced as compared with the first embodiment.

The reason is that the transmitting device 71 is configured to transmit data having a data amount that can be actually transmitted when receiving ACK data at the reception interval stored in the ACK reception history storage unit 76. is there.

<Third Embodiment>
Next, a third embodiment will be described. FIG. 5 is a block diagram showing the third embodiment.

Referring to FIG. 5, a communication system 90 according to the present embodiment includes a transmission-side device 91 and a reception-side device 31 connected via a network that can communicate with the transmission-side device 91.

The communication system 90 of the present embodiment stores and transmits downstream data in the network with the receiving-side device 31 in the configuration of the communication system 70 described in the second embodiment, as shown in FIG. The point of using the buffer amount of the transmission buffer in the relay apparatus 100 such as a base station or another server apparatus on the Web is different from the second embodiment.

Hereinafter, the configuration and operation different from those of the second embodiment will be mainly described, and the same reference numerals are given to the same components as those of the second embodiment, and description thereof will be omitted.

The transmission side device 91 includes a transmission side transmission / reception unit 92, a transmission stop monitoring unit 93, a transmission continuation unit 94, a shared transmission / reception unit 99, and an ACK history storage unit 96.

The transmission side transmission / reception unit 92 includes a transmission buffer 95.

The transmission continuation unit 94 includes a transmission buffer (not shown in FIG. 5).

The ACK history storage unit 96 stores information on the reception interval of ACK data each time the transmission side transmission / reception unit 92 receives ACK data from the reception side device 31.

Next, the operation of this embodiment will be described with reference to FIG.

FIG. 6 is a diagram illustrating a processing flow of the transmission-side device 91 in the present embodiment.

When the transmission side device 91 writes the data to the transmission buffer 95, the transmission buffer 95 sends the data of the written data amount that can be transmitted at a time without receiving the ACK to the shared transmission / reception unit 99. To the receiving side terminal 31 (step S171).

The transmission stop monitoring unit 93 checks whether transmission of data written in the transmission buffer 95 from the transmission buffer 95 has been stopped (step S172).

In step S172, the transmission stop monitoring unit 93 determines that the transmission buffer 95 has not stopped transmitting data when the transmission side device 91 has received ACK data from the reception side device 31 (step S172). NO).

In other words, the transmission stop monitoring unit 93 has the condition that “the size of the transmitted and ACK waiting data−the window size <0” in which the size of the data that has been transmitted and is waiting for the ACK is smaller than the window size and there is an empty window. If the above is satisfied, the following processing is performed. That is, the transmission stop monitoring unit 93 determines that the transmission buffer 95 has not stopped transmitting data because the transmission amount limit is not reached.

If the transmission buffer 95 is NO in step S172, the transmission buffer 95 executes processing for transmitting the data shown in step S171.

On the other hand, in step S172, the transmission stop monitoring unit 93 determines that the transmission buffer 95 has stopped transmitting data when the transmission side device 91 cannot receive ACK data from the reception side device 31 (step S172). In S172, YES).

That is, the transmission stop monitoring unit 93 satisfies the condition of “the size of the transmitted and ACK waiting data−the window size ≧ 0” in which the size of the data that has been transmitted and the ACK waiting is equal to or larger than the window size and the window is not empty. In this case, the following processing is performed. That is, the transmission stop monitoring unit 93 determines that the transmission buffer 95 has stopped transmitting data because the transmission amount limit has been reached.

In step S172, the transmission continuation unit 94 executes a process of step S173 described later in the case of YES.

The transmission stop monitoring unit 93 instructs the transmission continuation unit 94 to refer to the history of the ACK data reception interval of the ACK history storage unit 96 via the ACK history storage unit 96 (step S173).

The transmission continuation unit 94 refers to the history of the ACK history storage unit 96, and when the transmission side transmission / reception unit 92 continuously receives ACK data at the reception interval of the ACK data stored in the ACK history storage unit 96, Find the amount of data that can be sent.

At this time, the amount of data that can be transmitted by the transmission continuation unit 94 is, for example, as follows. That is, for example, when the maximum segment size of transmission data in TCP is 1500 bytes (12000 bits), and the transmission side device receives ACK data corresponding to the maximum segment size data from the reception side device every second, 12000 bits per second.

The transmission continuation unit 94 takes the data that the transmission buffer 95 is scheduled to transmit to the transmission buffer of the transmission continuation unit 94 based on the obtained data amount.

The transmission continuation unit 94 writes the data received from the transmission buffer 95 in the transmission buffer of the shared transmission / reception unit 99.

The shared transmission / reception unit 99 transmits the data written from the transmission continuation unit 94 to the reception-side device 31 (step S174).

Here, in the transmission side transmission / reception unit 92, if the reception interval of the ACK data referred to in step S173 is delayed, the transmission side device 91 transmits data at a transmission rate based on the reception interval of the delayed ACK data. Continue.

When the transmission continuation unit 94 continues to transmit data at the transmission rate described above, if the transmission buffer of the relay device 100 has finished transmitting, for example, half of the buffer amount, the transmission continuation unit 94 Execute the process. That is, the transmission continuation unit 94 sets the transmission rate of data transmitted from the subsequent transmission continuation unit 94 to, for example, a transmission rate obtained by reducing the above-described transmission rate by half.

Thereafter, when the transmission buffer of the relay device 100 has finished transmitting half of the remaining buffer amount described above, the transmission continuation unit 94 executes the following processing. That is, the transmission continuation unit 94 sets the transmission rate of data transmitted from the subsequent transmission continuation unit 94 to, for example, a transmission rate that is reduced to half of the transmission rate described above.

If the transmission stop monitoring unit 93 determines in step S172 that the transmission of data from the transmission buffer 95 is not stopped (NO in step S172), the transmission stop monitoring unit 93 executes the process shown in step S171.

In step 172, when the transmission-side device 91 confirms the stop of data transmission by the transmission buffer 95 and continuously transmits data by the transmission continuation unit 94, one of the following 1) to 7): Alternatively, control combining these may be performed.

That is,
1) The amount of data when the transmission continuation unit 94 continuously transmits data may exceed the amount of data that the transmission buffer 95 can transmit.

2) The transmission rate at which the transmission continuation unit 94 continuously transmits data may be a fixed rate or a variable rate. In the case of a variable rate, transmission is performed so that the transmission amount per unit time decreases. Also good.

3) The total transmission amount when the transmission continuation unit 94 continuously transmits data is a known buffer amount in a transmission buffer such as the relay device 100 illustrated in FIG. You may adjust so that the buffer amount of the real number multiple of the known buffer amount may not be exceeded.

4) As a known buffer amount of a transmission buffer such as a relay device in the network described in the item 3), a transmission amount limit value used when data is lost due to a change in the communication environment in the past, a window Size may be used.

Note that the transmission continuation unit 94 acquires the buffer amount of the relay device by, for example, estimating information by transmitting a large amount of data in advance or information notified in advance when the transmission-side device 91 operates the network. Can do.

5) The transmission continuation unit 94 uses the transmission side transmission / reception unit 92 to transmit dummy ACK data generated by the transmission side device 91 or a relay device that relays uplink reception data in the network when continuously transmitting data. You may make it receive.

Further, the transmission continuation unit 94 may perform processing assuming that ACK data is received as internal processing of the transmission side device 91 when data is continuously transmitted.

6) The transmission-side device 91 may relax the range of transmission amount restriction in the transmission buffer 95.

7) The transmission-side device 91 can communicate from a state in which the upstream direction cannot be communicated due to a change in the communication environment when the transmission continuation unit 94 described above continuously transmits data based on the reception rate of the ACK data. When returning to the correct state, the following processing may be executed. That is, when receiving the ACK data transmitted from the receiving side device 31, the transmitting side device 91 changes all or part of various setting information and various types of information indicating the internal state, which will be described later. May be.

Alternatively, the transmission side device 91 may return a setting value and an internal state, which will be described later, of the transmission side device 91 to a state before the transmission side device 91 stops receiving ACK data.

For example, in the case of TCP, the setting value and the internal state in the transmission side device 91 shown in the above section 7) are the setting values such as a generally known congestion window (cwnd) and slow start threshold (slow_start_threshold; ssthresh), and the like. It is an internal state such as a slow start phase or a congestion avoidance phase, and is various types of information related to a transmission amount limit and a process for adjusting the limit.

However, the various values indicating the setting value and internal state of the transmission side device 91 are not limited to the above-described values and information.

In step S172 described above, the transmission stop monitoring unit 93 determines that the transmission buffer 95 has stopped transmitting data when the size of the transmitted data in the transmission buffer 95 and the ACK waiting data reaches the transmission amount limit range. It was explained with an example of judgment.

However, the transmission stop monitoring unit 93 stops the transmission of data when at least one of the following conditions a), b), or c) is satisfied in addition to the stop determination conditions described above. You may make it judge. That is,
a) The case where the size of the transmitted data in the transmission buffer 95 and the ACK waiting data reaches the limit of the transmission amount, and the data transmission interval in the transmission side device 91 is delayed by a threshold value or more based on the RTT value.

B) The case where the size of the transmitted ACK waiting data in the transmission buffer 95 reaches the limit of the transmission amount, and the reception interval of the ACK data in the transmission side transmission / reception unit 92 exceeds a predetermined threshold.

c) In the case where the size of the transmitted and waiting ACK data in the transmission buffer 95 reaches the transmission amount limit range, and the data transmission interval in the transmission side device 91 is delayed by the threshold based on the RTT value, and When the reception interval of the ACK data in the transmission side transmission / reception unit 92 is equal to or greater than a predetermined threshold.

Subsequently, the flow of processing of the transmission side device 91 shown in FIG. 7 will be described.

In step S172, the transmission stop monitoring unit 93 determines that the transmission side device 91 cannot receive the ACK data from the reception side device 31 and the transmission buffer 95 has stopped transmitting data, and then transmits the transmission buffer. It is confirmed whether or not the stop of transmission of data from 95 has been released (step S175).

In step S175, the transmission stop monitoring unit 93 determines that the stop of data transmission in the transmission buffer 95 has not been released when the transmission side device 91 cannot receive ACK data from the reception side device 31 (step S175). NO).

That is, the transmission stop monitoring unit 93 satisfies the condition of “the size of the transmitted and ACK waiting data−the window size ≧ 0”, in which the size of the data that has been transmitted and is waiting for the ACK is equal to or larger than the window size, If so, do the following: That is, the transmission stop monitoring unit 93 determines that the stop of data transmission in the transmission buffer 95 has not been canceled because the transmission amount limit has been reached.

The transmission continuation unit 94 executes the ACK reception rate continuous transmission process shown in step S174 described above when NO in step S175.

On the other hand, the transmission stop monitoring unit 93 determines in step S175 that the transmission stop of data in the transmission buffer 95 has been released when the transmission side device 91 has received the ACK data from the reception side device 31 (step S175). In S175, YES).

In other words, the transmission stop monitoring unit 93 has the condition that “the size of the transmitted and ACK waiting data−the window size <0” in which the size of the data that has been transmitted and is waiting for the ACK is smaller than the window size and there is an empty window. If the above is satisfied, the following processing is performed. That is, the transmission stop monitoring unit 93 determines that the stop of data transmission in the transmission buffer 95 has been released because the transmission amount limit has not been reached.

When the transmission buffer 95 is YES in step S175, the transmission buffer 95 resumes the process of transmitting data shown in step S171 described above.

At that time, the transmission continuation unit 94 stops data transmission by the transmission buffer of the transmission continuation unit 94.

As described above, the present embodiment has an effect that the load on the network can be further suppressed than the effect described in the second embodiment.

The reason is that the transmission side device 91 transmits data of a data amount that can actually be transmitted at a variable rate when receiving ACK data at the reception interval stored in the ACK reception history storage unit 96. Because it was.

<Fourth Embodiment>
Next, a fourth embodiment will be described. FIG. 6 is a block diagram showing the fourth embodiment.

Referring to FIG. 6, the communication system 10 according to the present embodiment includes a transmission-side device 81 and a reception-side device 41 connected via a network that can communicate with the transmission-side device 81.

The transmission side device 81 includes the following configuration.

A transmitting side transmitting / receiving unit 82 that transmits data to the receiving side device 41 and receives ACK data as an acknowledgment from the receiving side device 41 corresponding to the data;
A transmission stop monitoring unit 83 for confirming whether or not transmission of data of the transmission side transmission / reception unit 82 is stopped;
A transmission continuation unit 84 that continues transmission of data when the transmission stop monitoring unit 83 determines that transmission of data of the transmission side transmission / reception unit 82 has been stopped.

Further, the reception side device 41 includes a reception side transmission / reception unit 42 that receives data from the transmission side device 81 and transmits ACK data corresponding to the data to the transmission side device 81.

As described above, this embodiment has an effect of suppressing the delay for the time waiting for data and ACK data and improving the communication efficiency as the communication system.

The reason is that the transmission continuation unit 84 is provided in the transmission side device 81 so as to continuously transmit the data without waiting for the ACK data.

(Hardware configuration example)
In the above-described embodiment, each unit shown in FIGS. 1, 3, and 5 can be regarded as a function (processing) unit (software module) of a software program. However, the division of each part shown in these drawings is a configuration for convenience of explanation, and various configurations can be assumed for mounting. An example of the hardware environment in this case will be described with reference to FIG.

FIG. 8 is a diagram illustrating an exemplary configuration of an information processing apparatus 200 (computer) that can execute a transmission-side apparatus according to an exemplary embodiment of the present invention. That is, FIG. 8 shows a computer (information) such as a server terminal capable of realizing the whole or a part of the transmission side devices of the

transmission side devices

11, 71, 91 shown in FIGS. It represents a hardware environment in which each function in the above-described embodiment can be realized. The direction of the arrow in FIG. 8 shows an example, and does not limit the direction of the signal between the blocks.

The information processing apparatus 200 illustrated in FIG. 8 includes a CPU (Central_Processing_Unit) 201, an input unit 202, an output unit 203, and a communication interface 205 with external devices (Interface: hereinafter, abbreviated as “communication I / F 205”). Including.

The information processing apparatus 200 also includes a hard disk 206 (nonvolatile storage device), a memory 207, and a reader / writer 208 that can read and write data stored in a nonvolatile storage medium 209 such as a CD-ROM (Compact_Disc_Read_Only_Memory). These components are general computers connected via a bus 204 (communication line).

The transmission side transmission /

reception units

12, 72, and 92 shown in FIGS. 1, 3, and 5 are, for example, an input unit 202 (reception unit of the transmission / reception unit of the transmission side device) and an output unit 203 (transmission of the transmission / reception unit of the transmission side device). Part).

The present invention described using the above-described embodiment as an example is the block configuration diagram (FIGS. 1, 3, and 5) referred to in the description of the embodiment for the information processing apparatus 200 shown in FIG. This is achieved by supplying a computer program capable of realizing the functions of the flowcharts (FIGS. 2, 4, and 6), reading the computer program to the CPU 201 of the hardware, and interpreting and executing the computer program.

Further, the computer program supplied to the apparatus may be stored in a non-volatile storage device such as the hard disk 206 or a readable / writable volatile memory 207.

In the above-described case, the computer program can be supplied to the hardware by a method of installing in the apparatus via various nonvolatile storage media 209 such as a CD-ROM, a communication line such as the Internet, and the like. Currently, a general procedure can be adopted, such as a method of downloading from the outside via the communication I / F 205.

In such a case, the present invention can be understood to be constituted by a code constituting the computer program or a nonvolatile storage medium 209 storing the code.

The present invention has been described above using the above-described embodiment as an exemplary example. However, the present invention is not limited to the above-described embodiment. That is, the present invention can apply various modes that can be understood by those skilled in the art within the scope of the present invention.

This application claims priority based on Japanese Patent Application No. 2015-055477 filed on Mar. 19, 2015, the entire disclosure of which is incorporated herein.

DESCRIPTION OF SYMBOLS 1 Communication system 10 Communication system 11 Transmission side apparatus 12 Transmission side transmission / reception part 13 Transmission stop monitoring part 14 Transmission continuation part 19 Shared transmission / reception part 20 Transmission buffer 31 Reception side apparatus 32 Reception side transmission / reception part 41 Reception side apparatus 42 Reception side transmission / reception part 70 Communication system 71 Transmission side device 72 Transmission side transmission / reception unit 73 Transmission stop monitoring unit 74 Transmission continuation unit 76 ACK history storage unit 79 Shared transmission / reception unit 80 Transmission buffer 81 Transmission side device 82 Transmission side transmission / reception unit 83 Transmission stop monitoring unit 84 Transmission continuation unit DESCRIPTION OF SYMBOLS 90 Communication system 91 Transmission side apparatus 92 Transmission side transmission / reception part 93 Transmission stop monitoring part 94 Transmission continuation part 95 Transmission buffer 96 ACK log | history preservation | save part 99 Shared transmission / reception part 100 Relay apparatus 200 Information processing apparatus 201 CPU
202 Input unit 203 Output unit 204 Bus 205 Communication interface 206 Hard disk 207 Memory 208 Reader / writer 209 Non-volatile storage medium

Claims

Transmitting transmission / reception means for transmitting transmission target data to the receiving device, and receiving an acknowledgment corresponding to the transmission target data from the receiving device;
A transmission stop monitoring means for confirming whether transmission of the transmission target data in the transmission side transmission / reception means is stopped;
A transmission continuation means for continuing transmission of the transmission target data on behalf of the transmission side transmission / reception means when the transmission stop monitoring means determines that transmission of the transmission target data by the transmission side transmission / reception means is stopped; A transmission apparatus comprising:
The transmission stop monitoring means is
The transmitting side transmitting / receiving means receives the size of the transmitted and ACK-waiting data and the ACK data that are the transmitted data and are waiting to receive ACK data representing the confirmation response. The transmission apparatus according to claim 1, wherein the transmission apparatus determines whether or not transmission of the transmission target data is stopped based on a transmission amount limit range indicating a data amount of data that can be transmitted without any problem.
The transmission stop monitoring means is
The transmission side transmission / reception means determines that the transmission of the transmission target data is stopped,
(I) Whether the size of the transmitted and ACK waiting data in the transmission buffer of the transmission side transmission / reception means has reached the transmission amount limit,
(II) The size of the transmitted and ACK waiting data in the transmission buffer reaches the transmission amount limit, and the transmission interval of the transmission target data in the own device is changed from the own device to the receiving device. The transmission apparatus receives the transmission target data from the time when the transmission target data was transmitted, and transmits the ACK data indicating that the reception apparatus has acknowledged the received transmission target data. Delayed by more than a threshold based on a delay time (hereinafter referred to as RTT value) observed between the transmitting device and the receiving device until the transmitting device receives the transmitted ACK data. Or if
(III) When the size of the transmitted and ACK waiting data in the transmission buffer reaches the limit of the transmission amount, and the reception interval of the ACK data in the transmission side transmission / reception means is equal to or greater than a predetermined threshold Or
(IV) The size of the transmitted and ACK waiting data in the transmission buffer reaches the transmission amount limit, and the transmission interval of the data in the own device is greater than or equal to the threshold based on the RTT value When the delay and the reception interval of the ACK data in the transmission side transmission / reception means is equal to or greater than the predetermined threshold,
The transmission device according to claim 2.
ACK history storage means for storing information indicating the reception interval when the ACK data is received,
The transmission stop monitoring means is
When it is determined that the transmission side transmission / reception unit has stopped transmission of the transmission target data, the transmission continuation unit is instructed to refer to the ACK history storage unit,
The transmission continuation means includes
Based on the information indicating the reception interval obtained as a result of referring to the ACK history storage means, the amount of data that can be transmitted when the transmission side transmission / reception means continuously receives the ACK data, The transmission device according to claim 2, wherein the transmission target data is transmitted based on a data amount.
The transmission continuation means includes
From the relay unit that relays the transmission target data transmitted by the own device between the own device and the receiving device, obtain information indicating the buffer capacity of the transmission buffer provided in the relay unit,
The ACK history storage that stores information indicating the reception interval of the ACK data received from the relay unit based on an instruction of the transmission stop monitoring unit that has determined that the transmission side transmission / reception unit has stopped transmission of the transmission target data Instructing them to refer to the means,
The transmission continuation means transmits the ACK data based on information indicating the reception interval obtained as a result of referring to the ACK history storage means and information indicating a buffer capacity of the transmission buffer of the relay means. When the transmission / reception means continuously receives the data amount that can be transmitted by the transmission continuation means,
The transmission device according to claim 4, wherein the transmission target data is transmitted based on the obtained data amount.
The transmitting side transmitting / receiving means includes
When the transmission continuation means continues to transmit the transmission target data,
(I) Whether the own device has received the ACK data,
(II) relax the range of the transmission amount limit of the transmission buffer in the transmission side transmission / reception means,
(III) ignoring the limit range of the transmission amount of the transmission buffer in the transmission side transmission / reception means,
(IV) The device itself receives dummy ACK data from the receiving device,
The transmission device according to claim 2, wherein at least one of the above is performed.
The transmission target data is transmitted to the reception device, and the transmission side transmission / reception unit that receives the confirmation response corresponding to the transmission target data from the reception device, and the transmission of the transmission target data in the transmission side transmission / reception unit is stopped. A transmission apparatus control method comprising: a transmission stop monitoring means for confirming whether or not; and a transmission continuation means for transmitting the transmission target data based on an instruction from the transmission stop monitoring means,
The transmission continuation means for continuing transmission of the transmission target data on behalf of the transmission side transmission / reception means when the transmission stop monitoring means determines that transmission of the transmission target data of the transmission side transmission / reception means has been stopped. A method for controlling a transmitting apparatus.
A transmission side transmission / reception function for transmitting the transmission target data to the reception device and receiving an acknowledgment corresponding to the transmission target data from the reception device;
A transmission stop monitoring function for confirming whether transmission of the transmission target data in the transmission side transmission / reception function is stopped;
The transmission continuation function for continuing transmission of the transmission target data instead of the transmission side transmission / reception function when the transmission stop monitoring function determines that transmission of the transmission target data by the transmission side transmission / reception function is stopped A recording medium in which a control program for a transmission apparatus that causes a computer to be realized is stored.
A transmission device capable of transmitting the transmission target data; and
A receiving device connected via a communication network capable of mutual communication with the transmitting device, and capable of returning an acknowledgment when receiving the transmission target data from the transmitting device;
The transmitter is
A transmitting side transmitting / receiving means for transmitting the transmission target data to the receiving device and receiving the confirmation response corresponding to the transmission target data from the receiving device;
A transmission stop monitoring means for confirming whether transmission of the transmission target data in the transmission side transmission / reception means is stopped;
The transmission continuation means for continuing transmission of the transmission target data on behalf of the transmission side transmission / reception means when the transmission stop monitoring means determines that transmission of the transmission target data by the transmission side transmission / reception means has been stopped. Including and
Communications system.