JPH09298575A - Data transmission control system and data transmission control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain data transmission with an optimum efficiency at all times matching the change in transmission environment of data such as change in a host protocol or a weather change. SOLUTION: In the data transmission control system conducting data transmission control by using a hierarchical protocol having layers corresponding to a layer 1 to a layer 4 at least among OSI reference models, selectors 8, 9 selecting functions used for data transmission control (re-transmission controller 1, error correction coder 2, code → physical value converter 3, transmission frame error detector 5, error correction decoder 6, and physical value → code converter 7) among functions of each layer below the layer 2 of the hierarchical protocol and the transmission control of data is conducted through the combinations of functions selected by the selectors 8, 9.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to wired or wireless transmission using a hierarchical protocol having at least layers corresponding to layers 1 to 4 of an OSI reference model (Open Systems Interconnection). The data transmission control system and the data transmission control which are suitable for optimal data transmission according to the change of the data transmission environment such as the change of the upper protocol and the change of the weather, etc. It is about the method.

[0002]

2. Description of the Related Art Conventionally, data transmission has been performed, for example, in "Interface '92 -6 No. 181" (1992).
, TCP / IP LAN (Transmission Control), pp. 149-161, etc.
Protocol / Internet Protocol Local Area Network)
It is standard to carry out based on a protocol defined hierarchically like the OSI reference model.

Regarding wireless data transmission, for example, 19th of "Dynamic Ham Series Packet Communication Handbook" (1995, CQ publisher).
The OSI reference model has been standardized, as described on pages 9-206. Hereinafter, a data transmission control technique using such a hierarchical protocol will be described.

FIG. 8 is a block diagram showing a configuration example of a conventional data transmission control system using a hierarchical protocol. This example particularly shows a configuration example of an apparatus that performs each functional operation positioned in a lower layer such as layers 1 and 2 in a hierarchical protocol. On the transmitting side, the retransmission control device 1 first assigns a sequence number to a frame received from a higher layer (upper protocol layer, layers 3 to 7 of the OSI reference model), and then an error correction coding device 2 gives an error correction code. The bit representation is replaced with the format, and the result is converted into a physical value by the code → physical value conversion device 3 and passed to the physical layer (transmission medium 4).

On the receiving side, the bit passed from the transmission medium 4 (physical layer) is converted into a code by the physical value → code conversion device 7, and then the error correction decoding device 6 decodes the error correction code. Do. Then, the transmission frame error detection device 5, which is the retransmission control device on the reception side, sends the frame to the upper protocol layer if there is no error in the received frame, but if there is an error in the received frame, the transmission The sequence number of the frame in which the error has occurred is sent to the retransmission control device 1 on the side as frame error information. As a result, the frame is retransmitted.

As described above, each conventional low-layer transmission apparatus has a transmission control function such as an error correction code function or a retransmission function for the purpose of apparently reducing bit errors in the physical layer. Many. In addition, the idea of a hierarchical protocol model requires that the functions of higher layers be designed and operated independently of the configuration of a transmission device of lower layers.

However, for example, in a digital data communication network that expands a wide area by connecting various different media, such as the Internet based on the TCP / IP protocol, which has been used explosively in recent years, the It can be said that “using higher layer technology” is the essence.
In this case, the transmission path is configured by using the same higher layer protocol in the situation where a plurality of different media are continuously connected through the switching device.
It is necessary to deal with not only a transmission error that occurs in the physical medium but also an error due to congestion in the switching device, end-to-end (ESs at both ends that are communication main bodies).

[0008] Therefore, it is necessary for the higher layer protocol to be provided with functions such as transmission error check and retransmission at the time of error. Therefore, for example, consider it to be a typical higher layer protocol that is currently widely used. TCP capable
In TCP, which is a typical transmission protocol in the / IP protocol family, such a function is incorporated.

However, when the higher layer also has a retransmission function at the time of a transmission error in this way, there may be a mismatch with the presence of the retransmission function implemented in the lower layer, which can be realized originally. In some cases, only the transmission efficiency that is considered to be significantly inferior to the expected transmission efficiency can be realized. Such a case will be described below by taking the TCP protocol and a transmission device for a mobile phone as an example.

In the TCP protocol, an acknowledgment (ACK packet) is sent from the time a packet is transmitted.
By measuring the time it takes to return the message, the time distance with the communication partner (RTT: Round Trip Time)
Is estimated and the retransmission timer is set. If there is no acknowledgment of the packet before the retransmission timer expires, it is assumed that the transmitted packet is lost and the packet is retransmitted.

On the other hand, in a digital transmission device for a mobile phone, a computer that is not so powerful as a mobile terminal device such as an electronic notebook cannot be used, and a non-procedure protocol is often used, so that a wireless section is used. Considering that the error rate is large, strong retransmission control is performed so that a transmission error does not occur even if the transmission delay and the transmission rate fluctuate significantly.

However, when the TCP having the above-mentioned retransmission function is transmitted using such a transmission device,
When a transmission error actually occurs, the transmission device also retransmits the packet, while TCP does not return the confirmation response (because the packet did not reach the destination in the first place), the packet with the same content is again transmitted. To the lower layer transmission device.

If the condition is not good, this is repeated, so that a plurality of packets having the same content are retained in the lower layer transmission device. Moreover, the lower layer transmission device must deliver all of the packets to the destination regardless of whether the packets have the same contents or not. But,
In the destination TCP, even if packets having the same content are sent from the transmission device, all of them are discarded, leaving one as a duplicate in the transmission path. As a result, TC
When viewed as P, it seems as if a considerable amount of time transmission is delayed in the wireless section as compared with the time when a physical failure actually occurs.

In addition, the existing low-layer transmission apparatus has a resending function control scheme and characteristics related to communication essence such as error detection / correction strength of an error correction code, which are compatible with disturbances such as weather changes and radio wave conditions. And cannot be changed dynamically. Therefore, if the physical layer condition assumed in the design of the transmission device is not satisfied, the transmission itself does not work well, and conversely, if it is better than the assumed condition, it should have been able to be exerted originally. However, there is a problem in that the transmission efficiency can not be realized.

[0015]

The problems to be solved by the prior art are that, in the prior art, when the protocols of the respective layers of the hierarchical protocol have overlapping functions, the overlapping functional operations are performed, and the lower layer. That is, it is not possible to dynamically change the characteristics related to the data transmission of the transmission device.
An object of the present invention is to solve these problems of the prior art, and to make it possible to always perform optimum data transmission in accordance with changes in the data transmission environment such as changes in upper protocols and changes in weather, and a data transmission control system. It is to provide a control method.

[0016]

In order to achieve the above object, the data transmission control system of the present invention comprises (1) OSI
In a data transmission control system that controls transmission of data using a hierarchical protocol having at least layers corresponding to layers 1 to 4 of a reference model,
Each function of each layer below layer 2 of the hierarchical protocol (retransmission control device 1, 1a, error correction coding device 2, 2a, code → physical value conversion device 3, 3a, transmission frame error detection device 5, 5a , Error correction decoding device 6, 6
a, physical value → code conversion device 7, 7a), a selection means (selection device 8, 9) for selecting a function used for data transmission control is provided, and each function selected by the selection device 8, 9 is selected. A feature is that data transmission control is performed in combination. (2) In the data transmission control system according to (1) above, the selection devices 8 and 9 include retransmission control devices 1 and 1a, error correction coding devices 2 and 2a, codes that are not used for data transmission control. By bypassing any one of the physical value converters 3 and 3a, the transmission frame error detectors 5 and 5a, the error correction decoders 6 and 6a, and the physical value-> code converters 7 and 7a, the combination of the respective functions can be achieved. It is characterized by performing. (3) In the data transmission control system according to (1) or (2), a plurality of selection devices 8 and 9 are prepared in advance for each function including communication conditions used for data transmission. Characteristics A,
B is provided with characteristic selection devices 8a to 8c and 9a to 9c for selecting the characteristics A and B used for data transmission control, and the characteristics A and B selected by the characteristic selection devices 8a to 8c and 9a to 9c and It is characterized in that data transmission control is performed by a combination of selected functions. Further, (4) in the data transmission control system according to any one of (1) to (3) above, in response to a change in a data transmission environment including a change in a hierarchical protocol type used for data transmission. The control means (characteristic selection control device 11) for controlling the selection operation of the characteristic selection devices 8a to 8c and 9a to 9c (and the selection devices 8 and 9) is provided. Also,
(5) In the data transmission control system according to (4) above, the control means (characteristic selection control device 11) determines the type of hierarchical protocol used for data transmission. Protocol detection means (protocol detection device 10) Equipped with,
The selection operation of the characteristic selecting devices 8a to 8c, 9a to 9c and the selecting devices 8 and 9 is controlled based on the determination result of the hierarchical protocol by the protocol detecting means. (6) In the data transmission control system according to (4) or (5), the control means (characteristic selection control device 11) collects error detection information by the error detection function of layer 2. An error information collecting unit (error information collecting device 12) is provided, and the selection operation of the characteristic selecting devices 8a to 8c, 9a to 9c and the selecting devices 8 and 9 is controlled based on the error detection information collected by the error information collecting unit. It is characterized by doing. (7) In the data transmission control system according to any one of (4) to (6) above, the control means (characteristic selection control device 11)
Comprises means for simulating the operation of the upper protocol above the layer 2 (upper protocol operation simulator 15), and based on the simulation result of the operation of the upper protocol by this simulating means, the characteristic selecting devices 8a-8c, 9a- It is characterized by controlling the selection operation of 9c and the selection devices 8 and 9. Also,
(8) In the data transmission control system according to any one of (4) to (7) above, the control means (characteristic selection control device 11) controls the data transmission in the physical transmission medium 4 of Layer 1 of the hierarchical protocol. A transmission medium observing means (transmission medium observing devices 13 and 14) for observing the transmission state is provided, and the characteristic selecting device 8 is based on the observation result by the transmission medium observing means.
It is characterized by controlling the selection operation of a to 8c, 9a to 9c and the selection devices 8 and 9. Further, the data transmission control method of the present invention is (9) a data transmission control method for performing data transmission control using a hierarchical protocol having at least layers corresponding to layers 1 to 4 of the OSI reference model, It is characterized in that the function used for data transmission control is selected from among the respective functions possessed by each layer of layer 2 and below of the hierarchical protocol, and the data transmission control is performed by the combination of each selected function. . (10) In the data transmission control method according to (9), each function of layer 2 and below is selected so as to maximize the throughput. Also, (1
1) In the data transmission control method according to any one of the above (9) and (10), a function not used for data transmission control is bypassed, and a function used for data transmission control is selected. To do. (12) In the data transmission control method according to any one of (9) and (11) above, layers 2 and 3 of a hierarchical protocol are used.
When TCP / IP is used as above, each function of layer 2 and below for performing data retransmission and error correction control is bypassed, and data retransmission and error correction control is performed by the function of layer 3 and above. . (13) In the data transmission control method according to any one of (9) to (12), the type of a protocol of layer 3 or higher of the hierarchical protocol is determined, and the type of the determined protocol is associated with , Layer 2 and lower layers are selected. Also, (14) above (9) to (13)
In the data transmission control method according to any one of items 1 to 3, the transmission quality of each layer of the hierarchical protocol is discriminated, and each function of layer 2 and below is selected according to the discriminated transmission quality of each layer. Characterize. Also, (15)
In the data transmission control method as described in (14) above, the transmission quality of each layer is the transmission quality within a fixed time of Layer 1 of the hierarchical protocol and within the fixed time of Layers 2 and 3 of the hierarchical protocol. The transmission quality and the transmission quality of the layer layer 4 or higher of the hierarchical protocol within a fixed time are included, and the transmission quality of at least one layer of each transmission quality is continuously measured, and the measurement result is a predetermined value. When a predetermined threshold value is exceeded within the time interval of, each function included in each layer of layer 2 and below is selected according to the measurement result. Also, (16)
In the data transmission control method as described in (15) above, the transmission quality of Layer 1 includes a bit error rate in a fixed time in a wired transmission medium, an electric field strength in a fixed time in a wireless transmission medium, and a time of electric field strength. The transmission quality of Layers 2 and 3 includes a frame error rate, a re-transmission frequency and a re-transmission frame within a fixed time in a wired transmission medium and a wireless transmission medium.
The above transmission quality is characterized in that it includes the block error rate, the block retransmission frequency, and the number of retransmission blocks during data transfer within a certain time from end to end including the wired transmission medium and the wireless transmission medium. (17) In the data transmission control method according to any one of (9) to (16), a plurality of characteristics A prepared in advance for each layer 2 or lower function including a communication condition used for data transmission ，
Characteristic A and B used for data transmission control are selected from B. (18) In the data transmission control method according to (17), the characteristics A and B prepared for each function of layer 2 and below are selected so as to maximize the throughput. Also, (1
9) In the data transmission control method according to any one of (17) and (18), the characteristics A and B possessed by the respective functions of layer 2 and below are data transmission rate characteristics, retransmission characteristics and error correction characteristics. In addition, increase / decrease of transfer rate characteristics and enhancement or reduction of retransmission characteristics and error correction characteristics are performed in conjunction with each function or individually.
It is characterized in that B is selected.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, a part of the function provided in the lower layer is bypassed by a manual or automatic switching operation or the like so that it can be selected not to be used. In this way, by partially enabling / disabling the function of the lower layer, for example, when the protocol of the higher layer has a retransmit function, the retransmit function of the lower layer is set to the transmitter / receiver side. By bypassing both of them, duplication of the retransmission function can be avoided.

Further, instead of the binary switch operation of using or not using a function of the lower layer, it is possible to select the characteristic relating to the data transmission of the lower layer from a plurality of options. This allows, for example, to dynamically change the data transmission rate (transfer rate), the communication conditions such as the file transfer method, etc. in response to the change of the upper protocol and the change of the state of the transmission line (wired / wireless). Therefore, optimal data transmission can always be performed in response to changes in the environment.

Further, by making it possible to determine the protocol of the higher (upper) layer to be used, and performing the bypass control and the characteristic change control of the function based on the determination result, for example, automatically for each packet to be transmitted. , It is possible to select the characteristics of lower layers, and it is possible to avoid duplication of the functions of each layer while simultaneously using a plurality of protocols. Also,
The physical layer status (physical characteristics of the wired / wireless transmission path) can be measured, and the retransmission control scheme and error correction code are dynamically selected according to the measurement result, and the status of the transmission path at that time The optimum transmission characteristic can be automatically selected according to the above, and it is possible to cope with the disturbance of the transmission line.

Further, by comprehensively combining the above-mentioned schemes, it is possible to avoid the duplicated operation of the functions of the respective layers and deal with the disturbance of the transmission line at the same time. Especially,
By making it possible to imitate the operation of the high level protocol, the operation of the high level protocol can be predicted and the operation corresponding thereto can be performed in advance. Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing a first embodiment of the configuration according to the present invention of the data transmission control system of the present invention. In FIG. 1, 1, 2, 3, 4 and 8 are a retransmission control device, an error correction coding device, a code → physical value conversion device, a transmission medium, and a selection according to the present invention, which are provided on the transmission side, respectively. 5, 6, 7, and 9 are transmission frame error detection devices, error correction decoding devices, physical value-> code conversion devices, transmission media, and transmission media provided on the receiving side, respectively. It is such a selection device.
Here, for simplification of description, the transmission side and the reception side are separated, but in reality, each device on the transmission side and the reception side has the same function and can perform transmission / reception operations. it can.

The operation (function) of each device will be described below.
The retransmission control device 1 assigns a sequence number to a frame received from a higher-layer protocol and controls the retransmission of a frame when a frame error occurs. The error correction coding device 2 replaces the bit representation of the data from the retransmission control device 1 with the error correction code format. The code → physical value conversion device 3 converts the data from the error correction coding device 2 into a physical value and sends it to the transmission medium 4.

The physical value → code conversion device 7 converts the bits from the transmission medium 4 into codes. Error correction decoding device 6
Performs the decoding process of the error correction code from the physical value → code conversion device 7. The transmission frame error detection device 5 sends the frame decoded by the error correction decoding device 6 to the upper protocol layer, and performs the frame error detection and coping process. That is, the transmission frame error detection device 5
Then, when an error in the received frame is detected, the sequence number of this frame is sent to the retransmission control device 1 on the transmitting side as frame error information. The error is dealt with by retransmitting the frame from the retransmission control device 1 based on the frame error information.

The selection devices 8 and 9 according to the present invention include a retransmission control device 1, an error correction coding device 2, a code → physical value conversion device 3, a transmission frame error detection device 5, an error correction decoding device 6, Each of the physical value → code conversion devices 7 is individually bypassed, and only the device used for transmitting the relevant data is selected and incorporated into the system to configure the system. The operation of the selection devices 8 and 9 will be described below.

In a data transmission system that uses a mobile telephone line that uses wireless, the characteristics of the communication path are inherently unstable and easily lost as compared with wired, and a communication error is large, the terminal requires a complicated transmission function. In order not to do so, so-called non-procedure protocol can be used as the higher-level protocol, the retransmission control devices 1 and 5 have strong error detection and retransmission control functions. When communication is performed using TCP on such a line and system, when a resending function of TCP and the resending function provided in resending control devices 1 and 5 compete with each other, an error occurs once in particular. After that, the phenomenon that the transmission efficiency is significantly reduced is observed.

Therefore, in the present embodiment, the selection devices 8 and 9 having the switch function are provided, and for example, when TCP is used as the upper protocol, the retransmission control devices 1 and 5 are preliminarily set.
Set to bypass and then configure the system.
This makes it possible to prevent unnecessary reduction in transmission efficiency after a transmission error has occurred once due to disturbance or the like. In the operation of the selection devices 8 and 9, only the switching of whether or not the retransmission control devices 1 and 5 are bypassed is performed, but by providing the selection means shown in FIG. Efficient data transmission control can be performed.

FIG. 2 is a block diagram showing a second embodiment of the configuration according to the present invention of the data transmission control system of the present invention. In this example, the retransmission control device 1a, the error correction coding device 2a, the code → physical value conversion device 3a, the transmission frame error detection device 5a, and the error correction decoding device 6
a, physical value-> code conversion device 7a has a plurality of different characteristic values. Then, instead of the selection devices 8 and 9 in FIG.
8c and 9a to 9c are provided, and the system configuration can be changed in response to changes in the communication environment more minutely and more flexibly than the system shown in FIG.

That is, the characteristic selecting devices 8a to 8c and 9a.
9c are respectively the retransmission control device 1a, the error correction coding device 2a, the code → physical value conversion device 3a, and the transmission frame error detection device 5a, the error correction decoding device 6a, the physical value → code conversion device of the connection destinations. 7a has a function capable of selecting various kinds of characteristics of each lower layer, and can set the optimum characteristics according to the protocol of the higher layer. It can also be bypassed if the function is not needed.

For example, when a user a uses the protocol A and a user b uses the protocol B, it is inevitable that the protocol used in the mobile phone line is only TCP / IP. There is no. In response to such a request, the characteristic selecting devices 8a to 8c and 9a to 9c provided in the present example select the optimum characteristic of each device according to each protocol, that is, the retransmission scheme and the error correction code. As a result, the data transmission control system of the present example can exhibit optimum transmission efficiency in each case.

Incidentally, the characteristic selecting devices 8a to 8 in this example.
c, 9a to 9c may be configured by providing the selection devices 8 and 9 in FIG. 1 with a function for selecting the characteristic of each function. In the data transmission control system of FIGS. 1 and 2 described above, the selection devices 8 and 9 and the characteristic selection device 8a ...
The activation of the selection operation of each of 8c and 9a to 9c is not particularly described, but manual switching may be performed. However, with the configuration shown in FIGS. 3 to 6, an automatic selection operation can be performed.

FIG. 3 is a block diagram showing a third embodiment of the configuration according to the present invention of the data transmission control system of the present invention. In the data transmission control system of this example, a protocol detection device 10 for discriminating a protocol of a higher (upper) layer is provided in the data transmission control system having the configuration shown in FIG. The protocol detection device 10 of this example
Has a function as a control unit of the present invention, and controls each of the characteristic selecting devices 8a to 8c and 9a to 9c.

It is widely practiced that one user uses a plurality of protocols at the same time, but the protocol detection device 10 determines the protocol for each packet received from a higher layer, and the result of the determination is subjected to characteristic selection control. The information is notified to each of the characteristic selection devices 8a to 8c and 9a to 9c. Dynamically responding to the determination result, each of the characteristic selection devices 8a to 8c and 9a to 9c has a retransmission control device 1a, an error correction coding device 2a, a code → physical value conversion device 3a, and a transmission frame error detection. A plurality of different characteristic values respectively possessed by the device 5a, the error correction decoding device 6a and the physical value → code conversion device 7a are selected to configure the system.

As described above, in this example, the function of discriminating the higher layer protocol is provided, and the optimum transmission characteristic is automatically selected according to the protocol currently processed by the system based on the discrimination result. You can This makes it possible to obtain the optimum transmission efficiency corresponding to the upper protocol for each packet.

FIG. 4 is a block diagram showing a fourth embodiment of the configuration according to the present invention of the data transmission control system of the present invention. The data transmission control system of this example is the same as the data transmission control system having the configuration shown in FIG.
1 and an error information collecting device 12 are provided. The error information collection device 12 detects the error information detected by each function of the lower layer, here, the frame error information notified from the transmission frame error detection device 5a and the error correction decoding device 6a.
The error detection information at the time of decoding notified from is collected.

Then, the characteristic selection control device 11 determines each of the characteristic selection devices 8a to 8c and 9a on the basis of the error information collected by the error information collection device 12 and the discrimination result (class of the upper protocol) of the protocol detection device 10. 9c
Is controlled. As a result, data transmission can be performed with a configuration that is more optimized for changes in the transmission status than the data transmission control system in FIG.

FIG. 5 is a block diagram showing a fifth embodiment of the configuration according to the present invention of the data transmission control system of the present invention. The data transmission control system of this example is the same as the data transmission control system having the configuration shown in FIG.
3 and 14 are provided, and the transmission medium 4 is a radio of a mobile phone line to constitute a data transmission control system for the mobile phone line.

The transmission medium observation devices 13 and 14 detect the characteristics of the transmission medium 4, for example, the state of radio waves. In a mobile phone line, various parameters such as radio field intensity greatly change depending on the movement of the communication subject, the condition between the antenna and the communication device, and the weather. In the data transmission control system of the present embodiment, such changes are detected by the transmission medium observing devices 13 and 14, and are sent to the characteristic selection control device 11 as transmission side transmission medium physical characteristic information and reception side transmission medium physical characteristic information. Be notified.

In the characteristic selection control device 11, the transmission side transmission medium physical characteristic information and the reception side transmission medium physical characteristic information from the transmission medium observing devices 13 and 14, the used protocol information from the protocol detecting device 10, and the error. Based on the error information from the information collection device 12, the selection operation of each of the characteristic selection devices 8a to 8c and 9a to 9c is controlled, and the retransmission control device 1a including the retransmission scheme, the error correction coding device 2a, the code → physical Value conversion device 3a, transmission frame error detection device 5a, error correction decoding device 6a, physical value →
The characteristics of each function of the code conversion device 7a are dynamically changed.
In this way, the transmission characteristics can be dynamically changed according to both the physical disturbance such as the radio wave condition and the characteristics of the higher layer protocol, and the optimum transmission efficiency is automatically obtained comprehensively. be able to.

FIG. 6 is a block diagram showing a sixth embodiment of the configuration according to the present invention of the data transmission control system of the present invention. In the data transmission control system of this example, the data transmission control system having the configuration shown in FIG. 3 is provided with the characteristic selection controller 11 shown in FIGS. This is a system configuration for mobile phones. Upper protocol operation simulator 1 of this example
5 has a function of simulating the TCP / IP protocol family as a higher layer protocol.

For example, the upper protocol operation simulator 15 estimates the retransmission timing from the upper layer. Based on this estimation result, the characteristic selection control device 11 immediately before the retransmission packet is actually sent, the retransmission control device 1a.
In response to this, a signal for stopping the retransmission operation by the retransmission control device 1a is issued. As a result, it is possible to prevent a collision between the retransmission operations of the upper layer TCP and the retransmission control device 1a.

FIG. 7 is a flow chart showing an example of an operation procedure according to the present invention of the data transmission control system of the present invention. When data transmission is started (step 701),
Whether or not it is necessary to change the combination or characteristics of each function in the lower layer is determined (step 702), and if it is changed (step 703), each function is selected so as to obtain the optimum transmission efficiency, that is, the maximum throughput. The combination or the characteristic is changed (step 704).

The determination in step 702 is made by a human operator based on a manual switching operation by the operator, an automatic determination based on a result of automatically discriminating the type of the upper protocol, and a transmission quality discrimination by a transmission error check function of each layer. There are automatic decisions based on the results. Regarding this transmission quality, there are transmission qualities of Layers 1 to 3 within a fixed time and transmission qualities of Layer 4 and above within a fixed time on the transmission path (wired and wireless). Of at least one layer (transmission quality)
, Which requires a combination of the functions of the lower layers or a change in the characteristics when each measurement result exceeds a certain value or a certain range within a predetermined time period. To decide.

The layer 1 transmission quality includes a bit error rate in a wired transmission line, an electric field strength in a wireless transmission line, a temporal fluctuation rate of the electric field strength, and a bit error rate. Includes a frame error rate in wired and wireless transmission paths, one or both of retransmission frequency and number of retransmitted frames, and the transmission quality of Layer 4 or higher includes end-to-end transmission including wired and wireless transmission paths. It includes the block error rate during data transfer, the block retransmission frequency and / or the number of retransmission blocks, or both.

The change of the combination of the respective functions in step 704 is carried out by using or bypassing the respective functions. In addition, the change of the characteristic of each function in step 704 may be performed by, for example, strengthening or reducing the retransmission or error correction function of each function individually or in conjunction with each other, and the transfer rate (transmission speed) of each function. Is increased or decreased (acceleration or deceleration) individually or in conjunction with each other.

Then, for example, as the upper protocol, T
When CP / IP is used, the above-mentioned electric field strength,
When a condition in which at least one item of bit error rate and frame error rate exceeds a certain reference value within a predetermined time interval is detected, the functions of layer 2 and below are bypassed and the functions of layer 3 and above are used. , Resend or error correction. The transmission quality check used in the determination in step 702 and the combination of the functions in step 704 may be individually performed, or may be mixed in one system and performed simultaneously. You can also Also, the operation shown in this example is
This can be performed by the data transmission control system having the configuration shown in FIGS.

As described above, in the data transmission control system of the present embodiment, first, by adopting the configuration shown in FIG. 1, the lower layer retransmission function can be bypassed for both transmission and reception. As a result, for example, when the retransmission control function is implemented in the higher layer, it is possible to avoid inconsistency with the retransmission control function, so that the transmission efficiency is improved as compared with the case without such a bypass function. be able to.

With the configuration shown in FIG. 2, the characteristics of each function of the lower layer can be set optimally according to the protocol of the higher layer to be transmitted, and the function of the lower layer can be set. Can be bypassed if it is not needed. That is, it is possible not only to simply turn on / off the retransmission control function, but also to change the retransmission timing or change the format of the error correction code. Therefore, when this is applied to a line that is expected to handle a plurality of protocols, it can be set so as to exhibit optimum transmission characteristics according to the intended use.

Further, by adopting the configuration of FIG. 3, it is possible to automatically select the optimum transmission characteristic according to the protocol currently processed by the system. Thus, when a plurality of protocols are used at the same time, for example, "TCP / IP" and so-called "Apple Tal" are used.
When two protocols called "k" are used at the same time, it is possible to set the optimum transmission characteristics for each packet, and it is possible to improve the transmission characteristics when using the multi-protocol.

Further, by adopting the configuration of FIG. 4,
By feeding back the error detection by the lower layer to the data transmission with the characteristic selected according to the upper protocol, it is possible to further select the optimal transmission characteristic and improve the transmission efficiency. Further, with the configuration shown in FIG. 5, the data transmission control system can automatically select a comprehensive optimum transmission characteristic by accounting for both the higher layer protocol and the physical characteristic of the transmission medium. So
In particular, when applied to multi-protocol and transmission in which the characteristics of the transmission medium greatly change with time, the transmission characteristics can always be kept at the highest performance according to the time.

Further, by having the function of imitating the higher layer protocol as the configuration of FIG. 6, the data transmission control system can predict the operation of the higher layer protocol, and particularly the operation of the higher layer protocol and its own operation. When the operations are inconsistent, the overall characteristics of the transmission path can be kept optimum by changing the operation to adapt to the higher level protocol. Also, as described in FIG.
Optimal transmission efficiency can be obtained by combining the functions or changing the characteristics in response to changes in the transmission environment.

The present invention is not limited to the configuration examples and operation examples of the embodiment described with reference to FIGS. 1 to 7, and various modifications can be made without departing from the spirit of the invention. For example, in FIG. 5, the characteristic selection control device 11
In the system including the protocol detection device 10 and the error information collection device 12 shown in FIG.
3 and 14 are added, even if the protocol detection device 10 and the error information collection device 12 are removed in the configuration of FIG. From the observation result of the transmission medium 4, it is possible to automatically select the optimum transmission characteristic according to the characteristic change of the transmission medium 4 such as physical disturbance. For example, when the radio wave condition is good, good performance can be obtained, and even when the radio wave condition is bad, it can be automatically applied to the corresponding performance. That is, it is possible to always maintain the optimum transmission characteristics according to the state of the physical line.

Further, the error information collecting device 12, the transmission medium observing devices 13 and 14, and the upper protocol operation simulator 15 shown in FIGS. 4 to 6 are provided in the characteristic selection control device 11, and each of them is provided in the characteristic selection control device 11. It may be configured to. By thus providing the error information collecting device 12, the transmission medium observing devices 13, 14 and the upper protocol operation simulator 15 in the characteristic selection control device 11, the error information collecting device 12, the transmission medium observing device 13, 14, upper protocol operation simulator 1
5, the transmission quality observing means according to the present invention can be configured, and each layer (layers 1 to 3 and layer 4) observed for a predetermined time.
It is possible to change the combination of functions and the characteristics corresponding to the above transmission quality.

[0053]

According to the present invention, even when the protocols of the respective layers of the hierarchical protocol have overlapping functions, the overlapping functional operations can be avoided, and the characteristics relating to the data transmission of the respective functions of the lower layers can be improved. It can be changed dynamically, and it is possible to always perform optimal and efficient data transmission according to changes in the data transmission environment such as changes in the upper layer protocol and changes in the weather.

[Brief description of drawings]

FIG. 1 is a block diagram showing a first embodiment of a configuration according to the present invention of a data transmission control system of the present invention.

FIG. 2 is a block diagram showing a second embodiment of the configuration of the data transmission control system of the present invention according to the present invention.

FIG. 3 is a block diagram showing a third embodiment of the configuration of the data transmission control system of the present invention according to the present invention.

FIG. 4 is a block diagram showing a fourth embodiment of the configuration of the data transmission control system of the present invention according to the present invention.

FIG. 5 is a block diagram showing a fifth embodiment of the configuration of the data transmission control system of the present invention according to the present invention.

FIG. 6 is a block diagram showing a sixth embodiment of the configuration of the data transmission control system of the present invention according to the present invention.

FIG. 7 is a flowchart showing an operation procedure example according to the present invention of the data transmission control system of the present invention.

FIG. 8 is a block diagram showing a configuration example of a conventional data transmission control system using a hierarchical protocol.

[Explanation of symbols]

1, 1a: Retransmission control device, 2, 2a: Error correction coding device, 3, 3a: Code → physical value conversion device, 4: Transmission medium,
5, 5a: transmission frame error detection device, 6, 6a: error correction decoding device, 7, 7a: physical value → code conversion device,
8, 9: Selection device, 8a to 8c, 9a to 9c: Characteristic selection device, 10: Protocol detection device, 11: Characteristic selection control device, 12: Error information collection device, 13, 14: Transmission medium observation device, 15: High-level protocol operation simulator.

Claims (19)

[Claims] 1. At least layer 1 of the OSI reference model
To a layer 4 corresponding to the layer 4 in a data transmission control system for controlling data transmission using a layered protocol, the layer 2 of the layered protocol is used.
Among the respective functions of each of the following layers, there is provided selection means for selecting a function to be used for transmission control of the data, and the transmission control of the data is performed by a combination of the respective functions selected by the selection means. Characteristic data transmission control system. 2. The data transmission control system according to claim 1, wherein the selecting means combines the respective functions by bypassing a function not used for the data transmission control. system. 3. The data transmission control system according to claim 1 or 2, wherein a plurality of the selection means are prepared in advance for each of the functions including a communication condition used for transmitting the data. A characteristic selection means for selecting a characteristic to be used for transmission control of the data from the selected characteristics, and the transmission control of the data is performed by the combination of the characteristic selected by the specific selection means and the selected functions. A data transmission control system characterized by. 4. The data transmission control system according to any one of claims 1 to 3, wherein the data transmission control system responds to a change in the data transmission environment including a change in the type of the hierarchical protocol used for transmitting the data. Then, the data transmission control system is provided with a control means for controlling the selection operation of the selection means. 5. The data transmission control system according to claim 4, wherein the control means comprises a protocol detection means for discriminating the type of the hierarchical protocol used for transmitting the data, and the protocol detection means is used. A data transmission control system, characterized in that the selecting operation of the selecting means is controlled based on a result of discrimination of the hierarchical protocol. 6. The data transmission control system according to claim 4 or 5, wherein the control means collects error detection information by an error detection function of the layer 2. Equipped with,
A data transmission control system for controlling the selecting operation of the selecting means based on the error detection information collected by the error information collecting means. 7. The data transmission control system according to claim 4, wherein the control means comprises:
Data transmission comprising means for simulating an operation of an upper layer protocol above the layer 2 and controlling the selecting operation of the selecting means based on a simulation result of the operation of the upper layer protocol by the simulating means. Control system. 8. The data transmission control system according to any one of claims 4 to 7, wherein the control means comprises:
Transmission medium observation means for observing the transmission state of the data in the physical transmission medium of Layer 1 of the hierarchical protocol is provided, and the selection operation of the selection means is controlled based on the observation result by the transmission medium observation means. A data transmission control system characterized in that 9. At least layer 1 of the OSI reference model
To a layer 4 corresponding to the layer 4 in the data transmission control method for controlling the transmission of data by using the layered protocol, among the respective functions of the layers 2 and below of the layered protocol, the data A data transmission control method, characterized in that a function used for the transmission control is selected, and the transmission control of the data is performed by a combination of the selected functions. 10. The data transmission control method according to claim 9, wherein each function of layer 2 and below is selected so as to maximize throughput. 11. The data transmission control method according to claim 9 or 10, wherein a function not used for transmission control of the data is bypassed and a function used for transmission control of the data is selected. A data transmission control method characterized by performing the following. 12. The data transmission control method according to claim 9, wherein TCP / IP is used as layers 2 and 3 of the hierarchical protocol, the data is retransmitted and the error is corrected. A data transmission control method, characterized in that the functions of layer 2 and below for performing control are bypassed, and the function of layers 3 and above is used to perform retransmission of the data and error correction control. 13. The data transmission control method according to claim 9, wherein the type of the layer 3 or higher protocol of the hierarchical protocol is discriminated and the type of the discriminated protocol is determined. A data transmission control method, characterized in that each function of layer 2 and below is selected. 14. The data transmission control method according to claim 9, wherein the transmission quality of each layer of the hierarchical protocol is determined, and the transmission quality of each layer is determined. A data transmission control method, characterized in that each function of layer 2 and below is selected. 15. The data transmission control method according to claim 14, wherein the transmission quality of each of the layers is a transmission quality of Layer 1 of the hierarchical protocol within a predetermined time and a layer 2 of the hierarchical protocol. 3 within a certain time, and layer layer 4 of the above hierarchical protocol
The transmission quality of at least one layer among the transmission qualities including the transmission quality within the above-mentioned fixed time is continuously measured, and the measurement result exceeds a predetermined threshold value within a predetermined time period. In case of
A method for controlling data transmission, characterized in that each function included in each layer of layer 2 and below is selected. 16. The data transmission control method according to claim 15, wherein the transmission quality of the layer 1 is a bit error rate in the fixed time in a wired transmission medium and a bit error rate in the wireless transmission medium in the fixed time. The transmission quality of the layers 2 and 3 includes the electric field strength, the temporal variation rate of the electric field strength, and the bit error rate, and the transmission quality of the layers 2 and 3 is the frame error rate, the retransmission frequency, and the retransmission frame in the fixed time in the wired transmission medium and the wireless transmission medium. The transmission quality of the layer 4 or higher includes the block error rate, the block retransmission frequency, and the number of retransmission blocks during data transfer within the fixed time from end to end including the wired transmission medium and the wireless transmission medium. A data transmission control method comprising: 17. The data transmission control method according to claim 9, wherein a plurality of characteristics are prepared in advance for each function of each layer 2 and below including a communication condition used for transmitting the data. From the above, a data transmission control method characterized by selecting a characteristic used for transmission control of the data. 18. The data transmission control method according to claim 17, wherein the characteristics prepared for the respective functions of layer 2 and below are selected so as to maximize the throughput. . 19. The data transmission control method according to claim 17 or 18, wherein the characteristics of each function of layer 2 and below include a transmission rate characteristic of the data, a retransmission characteristic and an error. Data transmission, including correction characteristics, wherein the transfer rate characteristics are increased / decreased and the retransmission characteristics and error correction characteristics are strengthened or reduced in conjunction with each of the functions or individually to select the characteristics. Control method.