JPH02143749A - Transmission control processing system - Google Patents

Abstract

PURPOSE:To average the quantity of communication and to reduce occurrence of collision by setting a wait time based on the quantity of communication obtained through the monitor of a transmission line and starting the transmission after the elapse. CONSTITUTION:A network consists of a node 1, a communication quantity monitor section 2, a wait time setting section 3, transmission lines 41, 42, an interconnection device 5 for network and a server 6. The wait time (time interval between transmission of preceding packet and transmission of succeeding packet) setting section 3 is provided to each of nodes 1 and sets a wait time as to a node 1 to which the section 3 belongs based on the quantity of communication of the transmission line 41 obtained by the communication quantity monitor section 2. A transmission node 1 awaits till a wait time elapses without making any transmission and sends no packet during the waiting even if the transmission line 41 is idle and sends a packet after the wait time elapses. Thus, the quantity of communication is averaged to reduce collision thereby optimizing the communication.

Description

[Detailed Description of the Invention] [Summary] This invention relates to a transmission control processing method that minimizes transmission data collisions.

A plurality of nodes that exchange data with each other for the purpose of making the time interval of data transmission variable based on the actual traffic.

a transmission path that connects the plurality of nodes, and in a network that requests a transmission right when a transmission request occurs in the node, a communication amount monitor unit that monitors the transmission path and determines the amount of communication; Each of the nodes is provided with a standby time setting unit that sets a standby time based on the determined traffic volume, and the standby time setting unit is configured to set the data transmission interval to be longer when the traffic volume is large. The waiting time is set so that the data transmission interval becomes short when the amount of communication is low, and when a transmission request occurs at the node, after the waiting time has elapsed, the node that generated the transmission request performs the transmission. Configure to start sending data related to the request.

(Industrial Application Field) The present invention relates to a transmission control processing method, and more particularly to a transmission control processing method that minimizes transmission data collisions.

One of the medium access control methods is a method in which a node that has generated a transmission request requests a transmission right at that time. This method inherently includes the possibility of data collision, so
Measures against data collisions are essential.

[Conventional technology]

The above methods can be divided into various methods based on countermeasures against data collisions, and C3MA/CD (Carrie
r 5ence Multiple Access w
This is typically the Colliston Detection method.

The C5MA/CD system has the advantage of being easy to configure, has good transmission efficiency, and that a failure in a node does not affect other nodes. collision is inevitable.

Therefore, in order to reduce the number of collisions, the C3MA/CD system adopts a first-order method.

(1) When starting transmission, the source node checks whether the transmission path is in use. This is performed by signal detection (carrier sense) on the transmission path. If the node is in use, the source node postpones transmission until the node is no longer in use, and then transmits (retransmits). The source node starts transmitting only if it is not in use.

(2) When a collision is detected, the source node immediately stops transmitting. Then, a waiting time is determined according to a predetermined algorithm, and retransmission is started after this waiting time has elapsed (backoff processing). These algorithms include those that use random numbers and those that use fixed priorities.

(1) eliminates meaningless collisions when starting transmission.

(2) reduces the probability that a collision will occur again during retransmission.

[Problem to be solved by the invention]

FIG. 14 and FIG. 15 are diagrams showing problems in the prior art, and in these diagrams, No. to N.

is a node, and L is a transmission path.

In the bus type network shown in FIG. 14, nodes N and N are communicating as shown in FIG. 15(i). When this communication ends, node Nt, which has been waiting for this, starts transmitting to node N4. However, since it takes a finite amount of time for other nodes to know that node N has started transmitting, a node that does not know about this, such as node N, sends a message to node N (because the transmission path is empty).

This causes a problem in that a collision occurs as shown in (ii) of FIGS. 14 and 15.

On the other hand, data related to the collision (ii) is retransmitted by backoff processing at each transmission source node. That is, as shown in (iii) of FIG. 15, for example, node N1 is first connected to node N.

After retransmission to node N4 is completed, node N2 starts retransmission to node N4. However.

Node N0, which had been waiting for the end of communication (retransmission) by node N, ends up starting transmission to node N.

As a result, as shown in FIGS. 14 and 15 (iv), a collision occurs and the transmission of the data that collided first is further delayed. In addition, there is also the problem that the bank-off processing may conversely reduce the utilization rate of the transmission path.

The above problems arise because during transmission (including retransmission), attention is focused only on whether or not the transmission path is in use at that time.

On the other hand, the present invention determines the usage status (degree of congestion) of the transmission path during transmission, that is, how many data transmission units such as frames or packets pass through the transmission path per predetermined time (transmission The focus is on the actual amount of communication (transmitted). In other words, according to the present invention, when the transmission time interval is varied based on the actual amount of communication and the amount of communication itself is averaged, collisions are reduced, resulting in less transmission delay and improved transmission efficiency. That is, this was done based on the knowledge that one communication is optimized.

In order to prevent the collision mentioned in (ii) above, for example, the frame sending interval may be changed.

This is disclosed in Japanese Patent Application Laid-Open No. 62-76341.

This technique changes the sending interval of frames by taking into account the finite time, so it is considered to be effective in preventing the above-mentioned (i) collisions. In addition, it cannot deal with collisions, etc. mentioned in (iv) above.In addition, since the frame transmission interval is not changed based on the actual communication amount, two communication amounts are averaged to reduce collisions and one communication is optimized. I can't.

An object of the present invention is to provide a transmission control processing method in which the time interval of data transmission is variable based on the actual amount of communication.

[Means to solve the problem]

FIG. 1 is a diagram illustrating the principle of the present invention and shows a network according to the present invention.

In FIG. 1, 1 is a node, 2 is a traffic monitor unit, and 3 is a node.
41 and 42 are transmission lines, 5 is a network interconnection device, and 6 is a server.

A plurality of nodes 1 from No. to N are provided, and are connected to each other by a transmission path 41 to form a (bus-type) network. That is, node l transmits data to other nodes l via the transmission path 41, and also receives data transmitted from other nodes.

The traffic monitor unit 2 is provided in each node 1, monitors the transmission line 41 to which the node 1 to which it belongs is directly (physically) connected, and determines the traffic.

Here, the 3 communication amount is a parameter indicating the usage condition fi (degree of congestion) of the transmission path 41, and how many units of data transmission (frames, packets, etc.) pass through the transmission path 41 per predetermined time (transmission directly or indirectly.

Note that hereinafter, the unit of data transmission will be simply referred to as a packet.

The standby time setting unit 3 is provided in each of the nodes 1 and sets the standby time for the node 1 to which it belongs based on the traffic of the transmission path 41 determined by the traffic monitoring unit 2 .

Here, the waiting time refers to the time interval from the transmission of the previous packet to the transmission of the next packet.

[For production]

FIG. 2 is an explanatory diagram of the operation of the present invention.

The traffic monitor unit 2 of each node N, to N, is as follows.

The amount of communication on the transmission path 41 is determined at all times or while the node 1 to which it belongs is logically connected to the network. Based on this communication amount, the standby time setting unit 3 sets the data (packet) transmission interval to be longer when the communication amount is large, and to increase the data (packet) transmission interval when the communication amount is small.
Set the waiting time so that the transmission interval is shortened. That is, the time interval for transmitting data (packets) is made variable depending on the actual amount of communication.

Now, at a certain node 11, for example, node N, node N
, when a request to send data occurs.

The node N, at that point requests the right to transmit, i.e.
If no other data is being transmitted, the data transmission process starts. For this purpose, the transmission source node N uses carrier sense to check whether the transmission path 41 is currently being used for other transmission. Then, when it is not in use, transmission processing is performed.

That is, the node N1 waits without transmitting a packet until the waiting time has elapsed. During this waiting period, even if the transmission path 41 is not in use, the node N1 does not transmit any packets.

After the waiting time has elapsed, transmission of data (packets) related to the transmission request to node N is started.

Node N returns a response to node N1 ((i) in Figure 2)
).

Please note that the amount of communication changes due to this transmission and response, so
Wait times vary (and often increase).

Next, when a transmission request occurs at nodes N and N2, transmission processing is performed in the same manner as described above. Node N
If a sufficiently long time has elapsed both from the sending of the packet ahead of node l ((1) in FIG. 2) and the sending of the packet ahead of node N2 (not shown), that is, the waiting time has elapsed. If so, nodes N1 and N8 start sending out packets. As a result, a collision occurs as shown in (11) in FIG. Also, the waiting time changes (becomes longer).

Assuming that the transmission of the packet ahead of node N is performed before the transmission of the packet ahead of node N1, first,
A new waiting time elapses in node N2, and the collided packet is retransmitted ((iii) in FIG. 2). This also causes the waiting time to change (become longer).

Before the waiting time elapses in node N1, node N0, whose waiting time has elapsed, starts transmitting to node N ((iv) in FIG. 2).

After this extended waiting time has elapsed.

Node N1 retransmits the collided packet ((v) in FIG. 2).

Note that the communication shown in FIG. 2(v) is not postponed indefinitely. That is, the communication is performed at least before the communication performed again by the other nodes 1 (nodes N2 and N) that have communicated after the communication shown in FIG. 2(i).

On the other hand, as the amount of communication decreases, the waiting time becomes shorter, and there may be cases where transmission is started immediately if a transmission request is received. Therefore, even though the amount of communication is small, the time required to start communication does not become unnecessarily long.

In this way, by making the time interval between data transmissions variable based on the actual amount of communication, it is possible to average out the five amounts of communication and reduce the occurrence of collisions. Therefore, the transmission delay time can be reduced and the transmission efficiency can be improved. Furthermore, it is possible to reduce the occurrence of collisions during retransmission after 5 collisions, and it is possible to prevent only specific nodes from communicating. As described above, according to the present invention, one communication can be optimized.

〔Example〕

(a) Description of one embodiment (1) Configuration The configuration shown in FIG. 1 will be further explained.

A network made up of nodes N0 to N and a transmission path 41 is connected by an interconnection device 5 to another network made up of a transmission path 42 and a plurality of nodes (not shown) to form a composite network. The interconnection device 5 consists of a bridge, router, or gateway, and is TCP
/To connect multiple networks using the IP protocol.

It has functions such as protocol conversion (converting differences in transmission speed and size of 5 packets).

The nodes N0 to N transmit and receive data to and from nodes of other networks via the interconnection device 5.

In this case, nodes N0 to N.

determines the transmission time interval based on at least the amount of communication on the transmission path 41 of its own network.

When sending to nodes in other networks.

For example, the amount of communication on the transmission path 41 of one's own network and/or the transmission path 42 of another network may be revealed.

For this purpose, the interconnection device 5 may be provided with the same number of traffic monitor units 2 and standby time setting units 3 as the number of connected networks, and the standby time may be determined and broadcast for each network.

The server 6 serves to reinforce only certain functions in the network, and includes, for example, a printer server that only performs printing, a calculation server that only performs high-speed calculations, and a disk server that serves as a large-capacity memory. Therefore, transmissions to the server 6 tend to concentrate. That is, data collisions are likely to occur in communications where the server 6 is the receiving node.

(2) Monitoring the amount of communication (a) FIG. 3 is a diagram showing an example of the configuration of the amount of communication monitoring section 3. As shown in FIG.

In FIG. 3, 31 is a carrier sensor, 32 is a timer, 33 is a clock generator, 34 to 36 are registers, and 37 is an accumulator.

The communication amount monitoring method shown in Figure 3 (and Figure 4) is as follows:
The time interval between packets transmitted on the transmission path 41 is determined and used as the communication amount.

The carrier sensor 31 constantly monitors the transmission line 41, detects when a packet passes on the transmission line 41, and sends a two-pass signal to the registers 34 and 35.

Timer 32 receives a clock signal from clock generator 33 and indicates the current time.

Registers 34-36 temporarily store two times or time intervals. That is, the registers 34 and 35 take in and store the time indicated by the timer 32 and the time indicated by the register 34 when each receives the 1-pass signal. Therefore, the register 34 indicates the time when a certain packet passed through the transmission path 41, and the register 35 indicates the time when another packet passed through the transmission path 41 immediately before the packet.

Accumulator 37 calculates the difference between the contents of registers 34 and 35 and stores it in register 36. Therefore, the register 36 indicates the time interval at which the two packets passed through the transmission line 41. The register 36 is referenced by the standby time setting section 3.

FIG. 4 is a flowchart of one communication amount information acquisition process.

(2) The carrier sensor 31 senses the packet, ie, the carrier, on the transmission path 41 and sends out a 1-pass signal.

(2) Upon receiving the passing signal, the register 35 takes in (reads) the value of the register 34 and latches it.

Further, the register 34 that receives the 1-pass signal takes in (reads) the value of the timer 32 and latches it.

(2) The accumulator 37 calculates the time interval between packet transmissions from the values in the registers 34 and 35 (by subtracting the value in the register 35 from the value in the register 34).

(2) The accumulator 37 sets the determined time interval in the register 36. The larger the time interval.

The amount of communication will be small.

(a) FIG. 5 is a diagram showing another example of the configuration of the communication amount monitor section 3, and in the figure, 38 is a shift register.

The communication amount monitoring method shown in Figure 5 (and Figure 6) is as follows:
The transmission time interval (average time interval) for a plurality of (three or more) packets transmitted on the transmission path 41 is determined, and this is used as the communication amount.

For this purpose, a shift register 38 is provided.

The shift register 38 stores the time at which each of the plurality of (N) packets has passed through the transmission path 41. For this purpose, the shift register 3 is a shift register with at least N stages. When the shift register 38 receives the passing signal from the carrier sensor 31, it takes the value of the register 34 into its first stage, latches it, and shifts the contents.

The first value fetched in the N stage is output to the register 35. Therefore, the register 35 indicates the time when the N packet before the packet that caused the passing signal passed through the transmission path 41.

FIG. 6 is a flowchart of communication amount information acquisition processing.

■ Perform the same process as process ■ in FIG. 4.

(2) Upon receiving the passing signal, the register 34 takes in the value of the timer 32 and launches it. Prior to this, the shift register 38 which has received the 5-pass signal takes the value of the register 34 into its first stage and latches it, and also transfers the value of the N stage (the value of the timer 32 for the N packets before) to the register 34. Output to. Register 3 that received the passing signal
5 takes in the output of the shift register 38 and latches it.

(2) The accumulator 3''7 first subtracts the value in the register 35 from the value in the register 34 to find the time required for N buckets to pass through the transmission path 41.

Next, this is divided by (N-1) to obtain the average transmission time interval for N packets.

■ Perform the same process as process ■ in FIG. 4.

(1) FIG. 7 is a diagram showing still another example of the configuration of the communication amount monitor section 3, and in the figure, 39 is a counter.

The communication amount monitoring method shown in Figure 7 (and Figure 8) is as follows:
The number of packets transmitted per unit time on the transmission path 41 is determined and this is taken as the communication amount.

For this purpose, a counter 39 is provided. counter 39
receives the passing signal from the 8-carrier sensor 31 and counts and amplifies it. That is, the number of packets that have passed on the transmission path 41 is counted by counting the number of signals that have passed one time.

Timer 32 receives a clock signal from clock generator 33 and sends a control signal to counter 39 and register 36 at a predetermined period.

The counter 39 that receives this control signal determines its contents (value).
is output to the register 36, and then reset. On the other hand, the register 36 that receives this control signal captures and latches the output of the counter 39.

FIG. 8 is a flowchart of the communication amount information acquisition process.

■ Perform the same process as process ■ in FIG. 4.

(2) Check whether the value of the timer 32 indicates the passage of a predetermined unit time (period M). The counter 39 and register 36 know this based on the presence or absence of the control signal.

(2) If no control signal is being sent, the counter 39 counts up upon receiving the 9 passing signal.

That is, since the unit time has not elapsed, counting of the number of packets is continued.

(2) When the timer 32 reaches a predetermined value, the timer 32 clears the value, assuming that the unit time has elapsed.

Prior to this, the timer 32 sends out a control signal. The counter 39 that received the control signal stores the value in the register 36.
After outputting to , clear its value. The register 36 that has received the control signal takes in the output of the counter 39 and launches it. Therefore, the register 36 indicates the number of packets passing through the transmission line 41 per unit time.

Thereafter, the counter 39 is counted up in response to the previous passing signal. On the other hand, the timer 32 has also started counting the passage of time, which means that counting of the number of packets within a new unit time has started.

The above three methods can also be realized by software, except for the processing performed by the carrier sensor 31.

Note that the contents of the register 36 may be stored in a predetermined storage area of the memory of each node, and the standby time setting unit 3 may refer to this.

(3) Packet acquisition FIG. 9 shows the packet acquisition processing flow according to the present invention.

■ If a packet exists (passed) on the transmission path 41,
Node 1 obtains this.

(2) The communication amount monitor section 2 monitors the amount of communication using the above-mentioned means and obtains the amount of communication.

■ The acquired information is subjected to CRC (cyclic redundancy).
dancy check) The data is sequentially sent to the arithmetic circuit and an error check is performed.

■ If there is an error, perform error handling.

■ Check whether the information was broadcast or not.
I can go around.

■ If the packet has not been broadcast, extract the address information from the packet and compare it with the own address.

■ If the two are not the same, the transmission is not to your own station.
Do not retrieve data.

If it has been broadcast, and if they are the same, processing is performed according to the protocol and data is acquired.

In this embodiment, the acquisition of 1 traffic information (processing ■) is incorporated into the packet acquisition procedure, and the acquisition of packets (processing ■) is incorporated into the packet acquisition procedure.
) is performed each time.

(4) Setting the waiting time (a) Setting algorithm ■ The waiting time can be calculated from the time interval between buckets and packets passing on the transmission path 41 according to a linear equation.

Here, the maximum waiting time is the upper limit value of the waiting time predetermined for each network, and the packet interval time can be obtained by referring to the register 36 described above. In the case of the method shown in FIG. 7 (and FIG. 8), it is necessary to calculate the time interval by dividing the unit time by the number of packets.

The longer the packet interval time (the lower the amount of communication).

The waiting time is shortened.

(2) The standby time can also be determined according to one of the 9th equations (2) to (2) from the relationship between the maximum (effective) transfer capacity of the transmission path 41 and the actually used transfer amount (transfer capacity).

. . . -. -Formula ■ Here, the "transfer capacity in use" is obtained by referring to the register 36. That is, since the configuration (size) of the packets can be known in advance, the "transfer capacity in use" can be determined by knowing the number of packets per unit time. In the case of the methods shown in FIGS. 3 and 5, it is necessary to calculate the number of packets per unit time from the value of the register 36.

The longer the transmission path 41 is used at a level closer to the maximum transfer capacity (the greater the number of packets per unit time), the longer the waiting time becomes.

Which of 2〇 or ■ to adopt depends on the network.

(2) The standby time can also be calculated according to one of the 9-order equations (1) to (2) from the relationship between the maximum transfer capacity of the transmission line 41 and the actually used transfer capacity and the number of nodes connected to the network.

−Waiting time Expression ■ = waiting time 2〇 One waiting time ・−・−・・Formula■ The node factor is determined by the quadratic equation (■) or (■).

Here, the transfer probability is the ratio of the time during which transfer is performed to the total connection time. Also, the number of nodes.

Number of nodes physically connected to the network.

or the number of nodes logically connected to the network.

This method is basically the same as method (2) above, and further reflects the number of nodes and transfer probability in the waiting time.

Note that the algorithm is not limited to the one described above (but can be modified in various ways, such as by using the above-mentioned methods together and selecting an appropriate one, or by adding node priority to the above-mentioned method).

Further, a different algorithm may be adopted for each node or each network.

(b) Wait time setting process FIG. 10 shows a waiting time setting processing flow.

(2) The standby time setting unit 3 refers to the register 36 and obtains data regarding the amount of communication.

(2) The standby time setting unit 3 calculates the standby time according to one of the algorithms described above using the acquired data.

(2) The standby time setting unit 3 sets the obtained standby time in a timer for packet transmission, etc., waits for the standby time to elapse, and then passes control to the node (means for controlling communication of the node).

(5) Packet Transmission FIG. 11 shows the packet transmission processing flow according to the present invention.

(2) When there is a transmission request, the transmitting node 1 adds a CRC to the data packet to be transmitted. This enables error detection at the receiving node 1.

(2) After the transmitting node 1 performs carrier sense and confirms that no other node is communicating using the transmission path 41, the transmitting node 1 moves to the transmitting process.

■ Through the above-described processing, a waiting time is set in the packet transmission timer and the like. This waiting time is based on the actual amount of communication, and is not a fixed time based on priorities as in the past, or a time determined based on probability or random numbers such as Poisson distribution.

The sending node 1 waits without transmitting until the waiting time has elapsed. During standby, even if the transmission path 41 becomes vacant (no longer in use), no packets are sent.
Send the packet after the waiting time has elapsed.

(2) The presence or absence of collision is checked, and if there is no collision, it is assumed that the sending node 1 has successfully transmitted the packet.

(2) If there is a collision, the sending node l performs a retry process, that is, a retransmission process according to the protocol.

The sending node 1 assumes that if the retransmission is successful, it is a successful transmission, and if it fails, it is assumed that a hard error has occurred.

(6) Example of communication FIG. 12 is a diagram showing the communication status.

Communication between a certain node 1 and another node 1 or server 6 consists of the transmission of a packet from the sending node 1 and a response from the receiving node 1 in response.

When the amount of communication is small, as shown in FIG. 12(A), when node N0 issues (sends) a processing request packet to server 6, a response is sent from server 6 to node N0. Done.

Terminate communication normally.

On the other hand, if the amount of communication is large, Figure 12 (B)
And the situation as shown in (C) is obtained. This situation is an example in which communications to the server 6 are concentrated.

First, as shown in FIG. 12(B), there is a node N.

issued a processing request to server 6.

Node N also issues a processing request to server 6.

At this time9. Node N0 is waiting for a response from server 6, but the response is not returned.

Node N, knowing that 9 communication traffic is large, postpones issuance of the response request packet. That is, since the amount of communication per packet is large, the standby time is set to lengthen the time interval between packet transmissions.

Furthermore, as shown in FIG. 12(B), the node N
, and N issue processing requests to the server 6.

Therefore, at this time, node N0 still has server 6.
Although there is no response from , the issuance of the response request is postponed because the communication volume is large.

If a series of processing requests to the server 6 disappears, the communication volume decreases, and a response is not obtained from the server 6, the 12th
As shown in FIG. 3C, the node N0 issues a response request to the server 6. That is, since the amount of communication has decreased, the standby time is set so as to shorten the time interval between packet transmissions.

Upon receiving the response request, the server 6 notifies the node N0 that the process is in progress or that the process has been completed.

After this, node N! , N y and N similarly make a response request to the server 6 and receive a notification from the server 6 in response.

[Yes]) Other Embodiments Although the above explanation has been about a bus type network, the present invention is as shown in FIG. 13.

It is also effective for ring type (or loop type) networks.

Furthermore, for example, one embodiment of the present invention may be carried out only after a collision as shown in (ii) of FIG. 2 occurs.

〔Effect of the invention〕

As explained above, according to the present invention, in the transmission control process, the waiting time is set based on the traffic volume obtained by monitoring the transmission path, and transmission is started after the waiting time has elapsed. can be averaged, reducing the occurrence of collisions, shortening transmission delay time, and improving transmission efficiency.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the principle configuration of the present invention. FIG. 2 is an explanatory diagram of the operation of the present invention. FIGS. 3, 5, and 7 are diagrams showing an example of the configuration of a communication amount monitor section. Figures 4, 6, and 8 are traffic information acquisition processing flows. Figure 9 is packet acquisition processing flows. Figure 10 is wait time setting processing flow. Figure 11 is packet transmission processing flow. Figure 12 is communication status. Diagram showing. FIG. 13 is a configuration diagram of another embodiment. FIG. 14 and FIG. 15 are diagrams showing problems in the prior art. 1 is a node, 2 is a traffic monitor section, 3 is a standby time setting section, 41 and 42 are transmission paths, 5 is an interconnection device, and 6 is a server. Patent Applicant Pfn Co., Ltd. Agent Patent Attorney Mori 1) Hiroshi (2 others) - Men's 4 figures dead) Momme and reason 70 - P160 Otagashii 15t1 - Sikpezo p (17) Okashitako 44? Furinyo Show 1 ``Figures are shown 1 Maggett 1i 4 Correct 1 foot 0 - 1PJ9 Figure Mari-nt Send'' 343 Weeks Flow Page 1 tA Ma brother 1 Show 1 solid (1v) Juhikoku Yuhi Maki Nasuno 1st era of crushing, 5 eup

Claims (1)

[Claims] A system comprising a plurality of nodes (1) that mutually transmit and receive data, and a transmission path (41) connecting the plurality of nodes (1), wherein a transmission request is generated in the node (1). In a network that requests transmission rights from time to time, a communication amount monitor unit (2) that monitors the transmission path (41) and obtains the amount of communication; and a standby time that sets a standby time based on the determined amount of communication. A setting unit (3) is provided in each of the nodes (1), and the standby time setting unit (3) is configured to increase the data transmission interval when the communication volume is large, and to increase the data transmission interval when the communication volume is low. The waiting time is set so that the transmission interval of A transmission control processing method characterized by starting transmission of data related to a request.