JPH08251228A - Fixed transfer rate communication method - Google Patents

Abstract

PURPOSE: To provide high-rate and high-transmission-efficiency communication by reducing the amount of arithmetic for deciding whether data to be exchanged are valid or invalid in the case of controlling data rate by inserting invalid data. CONSTITUTION: In the case of transmitting invalid data in a memory 6 and valid data in a buffer memory 8 on the side of a transmitter 1, under the control of a CPU 4, an identification code for deciding whether data are valid or invalid is applied synchronously with the frame pulse of a communication line 3 corresponding to the transmission status of validness/invalidness stored and updated in a memory 7. On the side of a receiver 2, a CPU 11 fetches the data corresponding to the frame pulse of the communication line 3, inspects whether it is the identification code or not and decides whether the next data to be received are valid or invalid corresponding to the identification code and the reception status of validness/invalidness stored and updated in a memory 13. Thus, since it is processed and decided synchronously with the frame pulse whether data are valid or invalid, it is not necessary to inspect all the data, arithmetic is simplified and high-rate and high-efficiency communication is possible.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication method suitable for performing communication at a variable data rate using a communication network which is unidirectional and has a fixed transfer rate.

[0002]

2. Description of the Related Art FIG. 5 shows a configuration example of a conventional communication system. In FIG. 5, 1 is a transmitter, 2 is a receiver,
Reference numeral 3 is a unidirectional and fixed rate communication line. In FIG. 5, data for transmission is created by the transmitter 1, passes through the communication line 3, and is received and processed by the receiver 2.

As constituent elements of the transmitter 1, 4 is a CPU for transmission control of the transmitter 1, 6 is a memory for storing invalid data format, and 8 is a buffer memory for storing transmission data. The transmitter 1 uses the CPU 4 to read data from the buffer memory 8 for transmission and transmit the data to the communication line 3.

As components of the receiving device 2, 11 is a CPU for receiving control of the receiving device 2, 14 is a buffer memory for storing received data, and 17 is a memory for storing invalid data format. The receiving device 2 uses the CPU 11 to read data from the communication line 3 and transfer the data to the buffer memory 14.

FIG. 6 shows a processing flow in the transmission device in the conventional communication system. In the transmitter 1, the data to be transmitted is read from the buffer memory 8 and if there is data, it is transmitted to the communication line 3. If there is no data, invalid data in the memory 6 is transmitted to adjust the communication speed.

Further, FIG. 7 shows a processing flow in the receiving device in the conventional communication system. The receiving device 2 compares the data transmitted through the communication line 3 with the invalid data format stored in the memory 17. If it is not invalid data, the data is taken in as valid data. Further, if the data matches the invalid data, the data transfer rate is adjusted by discarding the data as invalid data.

In such a conventional communication method, a pattern that does not appear in the transmission data as invalid data is prepared in advance. If such a pattern cannot be prepared, it is detected whether the same pattern as the invalid data is included in all the transmitted data. Performs a process to restore the data that was replaced on the side.

[0008]

As described above, in the receiving apparatus according to the conventional communication system for performing variable speed data communication using a fixed speed communication line, all received data are inspected to determine whether they are valid or invalid. Since the determination is performed, there is a problem that it is necessary to perform a large amount of calculation and it is difficult to increase the transmission speed. Also, if the format of invalid data that does not match a part of the transmitted data cannot be prepared in advance, the sender checks all the data, and if it matches the invalid data, replaces it. It is necessary to perform a process of inspecting and replacing the replaced data. Since these processes require a large amount of calculation at the time of transmission and reception, it is difficult to increase the transmission speed.

An object of the present invention is to reduce the amount of calculation at the time of transmission and reception in order to solve such problems.
An object of the present invention is to provide a communication method that enables high-speed communication with high transmission efficiency.

[0010]

In order to achieve the above object, according to the present invention, when data is transmitted from a transmitting device to a receiving device via a communication line having a fixed transfer rate, the transmitting device is currently transmitting. Stores the valid data or invalid data as the transmission status, and when there is no data to be transmitted, the invalid data is transmitted so as to have a constant data rate, and the receiving device receives the valid data or invalid data. In the communication method of storing data as a reception status and discarding the reception data when the reception status is invalid data reception, in the transmission device, when the transmission status is changed, the frame of the communication line is changed. An identification signal is given to a predetermined area of the transmission data in synchronization with the pulse, and the signal is transmitted. It captures the received data in synchronism,
A fixed transfer rate communication method that treats the reception status as changed when the identification signal is detected in a predetermined area of the reception data is used as means.

In the above communication method, in the transmitting device,
When transmitting valid data, it is checked whether or not the data in the predetermined area synchronized with the frame pulse of the communication line is the same as the identification code, and if they are the same, they are replaced with different data. It is preferable to restore the replaced data to the original data when the replaced data is detected in a predetermined area of the received data when the received data is captured in synchronization with the frame pulse of the line. .

Further, it is preferable that a predetermined area of the transmission data to which the identification code is added is positioned at the beginning or the end of the transmission data.

Further, it is suitable to be applied when the communication line is unidirectional.

[0014]

According to the communication method of the present invention, the transmitting side adds the identification code synchronized with the frame pulse to the transmission data for transmission, and the receiving side receives the identification code in synchronization with the frame pulse to enable / disable the data. By making the above determination, it is not necessary to inspect all data, and it is possible to process and determine the validity / invalidity of the transmitted / received data by a simple calculation, enabling high-speed communication.

On the transmitting side, when transmitting valid data, it is checked whether or not it is the same as the identification code in synchronization with the frame pulse, and if they are the same, they are replaced with different data and transmitted, and on the receiving side. When the replaced data is detected in synchronization with the frame pulse, by restoring it, it is not necessary to check all the data even when the identification code that does not match the transmission data cannot be prepared. By simplifying the calculation, high-speed communication with high transmission efficiency is possible.

[0016]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 shows a configuration example of a communication system according to an embodiment of the present invention. In FIG. 1, 1 is a transmitter, 2
Is a receiving device, and 3 is a communication line in a fixed rate communication line network. In FIG. 1, data for transmission is created by a transmitter 1, passes through a communication line 3 in a fixed rate communication line network, and is received and processed by a receiver 2.

Reference numerals 4 to 10 are examples of constituent elements of the transmitting apparatus 1, 4 is a transmission control CPU of the transmitting apparatus 1, 5 is a memory for storing an identification code, 6 is a memory for storing an invalid data format, and 7 is a memory. An invalid data transmitting identification data storage memory that stores a transmission status indicating whether or not invalid data is being transmitted, 8 is a buffer memory for storing transmission data, 9 is a frame pulse separation circuit, and 10 is a frame pulse supply line. . This transmitting device 1 uses the CPU 4
It is assumed that data is read from the transmission buffer 8 and transmitted to the communication line 3.

Reference numerals 11 to 16 are examples of constituent elements of the receiving device 2, 11 is a CPU for receiving control of the receiving device 1, 12 is a memory for storing an identification code, and 13 is a receiving status indicating whether invalid data is being received. Memory for storing invalid data being received, identification data storage memory, 14 data reception buffer memory, 15 frame pulse separation circuit, 16
Is a frame pulse supply line. This receiving device 2 is C
Read data from the communication line 3 using the PU 11,
It shall be transferred to the buffer memory 14.

In this configuration example, the frame pulse is separated from the communication line 3 by the frame pulse separation circuit (9 and 15) inside the transmitter 1 or the receiver 2 and is transmitted through the frame pulse supply line (10 and 16) to the CPU (4 And 11).

FIG. 2 shows a processing flow on the transmitting device side according to this embodiment, and FIG. 3 shows a processing flow on the receiving device side. In addition,
The processing flow in this case is a processing flow when the same pattern as the identification code does not exist in the transmission data. An operation example in this embodiment will be described with reference to FIGS. 1, 2, and 3. This operation example is an example immediately after sending valid data from the transmission device 1 of FIG. 1 to the reception device 2. Therefore, the transmission status of the memory 7 is transmitting valid data, the buffer memory 8 is in the state of transmitting data, and the reception status of the memory 13 is receiving valid data.

First, the processing on the transmitting side will be described. CPU4
Is used to read data from the buffer memory 8 for transmission. Since there is data in the buffer memory 8, the transmission status of the memory 7 is determined, and since valid data is being transmitted at present, the process A of FIG. 2 (the process of transmitting the read data to the communication line 3 as it is) is performed. Again, the data is read from the buffer memory 8 for transmission. Assuming that there is no transmission data in the buffer memory 8 this time, the transmission status of the memory 7 is determined, and since valid data is currently being transmitted, processing C of FIG. 2 is performed. That is, the identification code is stored in the memory 5
The invalid data of the memory 6 is read out, added to the end of the identification code, and transmitted to the communication line 3. At that time, the transmission status of the memory 7 is rewritten during invalid data transmission. Again, the data is read from the buffer memory 8. If there is no transmission data next time, similarly, the transmission status of the memory 7 is judged,
Since invalid data is currently being transmitted, the process D of FIG. 2 (the process of transmitting only invalid data without adding an identification code) is performed. Again, the data is read from the buffer memory 8. This time, if there is transmission data, the transmission status of the memory 7 is judged, and since invalid data is currently being transmitted,
Processing B (processing of reading the identification code from the memory 5, synchronizing with the frame pulse, adding the data read from the buffer memory 8 after the identification code and transmitting the data to the communication line 2). At that time, the transmission status of the memory 7 is rewritten during transmission of valid data.

Next, the processing on the receiving side will be described. The data sent from the transmitting side is valid data without identification code, invalid data with identification code, invalid data without identification code,
It is valid data with an identification code. CPU 11 on the receiving side
Then, the data received from the communication line 3 is inspected in synchronization with the frame pulse of the frame pulse supply line 16. If the inspection result does not match the identification code stored in the memory 12, the reception status of the memory 13 is inspected, and since the valid data is being received, the process E of FIG. To the buffer memory 14 for reception). The received data is inspected again in synchronization with the next frame pulse. Next, assuming that the received data matches the identification code, the receiving status of the memory 13 is receiving valid data, so the processing G (the subsequent data is discarded as invalid data). Process). At this time, the reception status of the memory 13 is changed to invalid data being received. Again, the received data is inspected in synchronization with the next frame pulse. Next, if the received data does not match the identification code, the reception status of the memory 13 is receiving invalid data, so the processing F (processing to discard the received data as invalid data is performed. ) Is executed. Again, the received data is inspected in synchronization with the next frame pulse. Next, assuming that the received data matches the identification code, the reception status of the memory 13 is receiving invalid data, so the processing H (the received data excluding the identification code is The data is sent to the data bus as valid data and is written in the receiving buffer memory 14). At this time,
The reception status of the memory 13 is changed to valid data being received.

FIG. 4 is a conceptual diagram showing the relationship between the format of transmission data and frame pulses. By inserting invalid data between transmission data (valid data), the data rate in a fixed rate communication line is adjusted.
An identification code is added to the beginning or the end of the transmission data and the invalid data in synchronization with the frame pulse.

When a pattern that does not appear in the transmission data cannot be prepared in advance as an identification code, the process shown in FIG.
The following processing is added to the processing A of 1. That is, on the sending side,
In synchronization with the frame pulse, only the data having the same length as the identification code is inspected, it is checked whether or not the pattern is the same as the identification code, and if it is the same, another data is replaced. Similarly,
The following process is added to the process E of FIG. 3 (reception side process). That is, it is checked whether or not the data compared with the identification code in synchronization with the frame pulse is the previously notified replaced pattern, and if it is the replaced pattern, the original process is performed. Since all the processes are performed in synchronization with the frame pulse, it is not necessary to check all the data, and it can be realized with a small amount of calculation.

The identification code may be attached to an area at a predetermined position other than the beginning or the end of the transmission data and transmitted.
In this case, the receiving side needs to perform a process of dividing the received data in the buffer memory into invalid data and valid data based on the position of the identification code. Further, the present invention is naturally applicable to a bidirectional communication line. However, when applied to a unidirectional communication line, the band becomes low, which is advantageous for multiplexing.

[0027]

As is apparent from the above description, according to the fixed transfer rate communication method of the present invention, the transmission side adds the identification code to the transmission data in synchronization with the frame pulse of the communication line, and transmits and receives. Since the side receives the identification code in synchronization with the frame pulse and determines whether the data is valid or invalid, it is not necessary to check all the data, and the valid / invalid processing of the transmitted / received data can be performed by a simple calculation. The determination can be performed, and the communication can be realized with a smaller amount of calculation as compared with the conventional communication method, so that the communication can be performed at high speed and with high transmission efficiency.

Further, at the transmitting side, when transmitting valid data, it is checked whether or not it is the same as the identification code in synchronization with the frame pulse of the communication line, and if it is the same, it is replaced with different data and transmitted. When the receiving side detects the replaced data in synchronism with the frame pulse and returns it to the original, it is necessary to inspect all the data, especially when the identification code that does not match the transmitted data cannot be prepared. Without
Since the calculation is also simplified, high-speed communication with high transmission efficiency becomes possible.

Further, in the case where the identification code is positioned and added at the beginning or the end of the transmission data, in particular, the calculation regarding the validity / invalidity of the data is simplified, and the transmission efficiency is further improved.

Further, when the present invention is applied to a unidirectional communication line, the band becomes particularly low, which is advantageous for multiplexing.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration example of a communication system according to an embodiment of the present invention.

FIG. 2 is a diagram showing a processing flow of a transmission device according to the above embodiment.

FIG. 3 is a diagram showing a processing flow of the receiving apparatus according to the embodiment.

FIG. 4 is a diagram showing an outline of a relationship between a data format on a communication line and a frame pulse signal in the above embodiment.

FIG. 5 is a diagram showing a configuration example of a conventional communication system.

FIG. 6 is a diagram showing a processing flow of a transmission device in a conventional communication system.

FIG. 7 is a diagram showing a processing flow of a receiving device in a conventional communication system.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Transmitting device 2 ... Receiving device 3 ... Communication line 4 ... Transmission control CPU 5 ... Identifier storage memory 6 ... Invalid data format storage memory 7 ... Invalid data transmitting identification data storage memory 8 ... Transmission data storage Buffer memory 9 ... Frame pulse separation circuit 10 ... Frame pulse supply line 11 ... Reception control CPU 12 ... Identifier storage memory 13 ... Invalid data receiving identification data storage memory 14 ... Received data storage buffer memory 15 ... Frame pulse Separation circuit 16 ... Frame pulse supply line

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Koichi Ito 1-1-6 Uchisaiwai-cho, Chiyoda-ku, Tokyo Nihon Telegraph and Telephone Corporation (72) Hideki Sakamoto 1-1-6 Uchisai-cho, Chiyoda-ku, Tokyo Nippon Telegraph and Telephone Corporation

Claims (4)

[Claims] 1. When performing data communication from a transmitting device to a receiving device via a fixed transfer rate communication line, the transmitting device stores whether the data currently being transmitted is valid data or invalid data as a transmission status, And when there is no data to be transmitted, invalid data is transmitted so that the data rate is constant, and the receiving device stores whether the received data is valid data or invalid data as a reception status and the reception status is invalid data reception. In the communication method of discarding the received data, when the transmission status is changed, the transmission device assigns an identification signal to a predetermined area of the transmission data in synchronization with a frame pulse of the communication line. In the receiving device, the received data is captured in synchronization with the frame pulse of the communication line, and the location of the received data is acquired. Fixed transfer rate communication method of the case where the detected identification signal to the region, and wherein the handle as the reception status has been changed. 2. The transmitting device checks whether or not the data in a predetermined area synchronized with the frame pulse of the communication line when transmitting the valid data is the same as the identification code, and if they are the same, different data is obtained. In the receiving device, when the replaced data is detected in a predetermined area of the received data when the received data is captured in synchronization with the frame pulse of the communication line, the replaced data is replaced with the original data. The fixed transfer rate communication method according to claim 1, wherein the fixed transfer rate communication method is performed. 3. The fixed transfer rate communication method according to claim 1, wherein a predetermined area of the transmission data to which the identification code is added is positioned at the beginning or the end of the transmission data. 4. The fixed transfer rate communication method according to claim 1, 2 or 3, wherein the communication line is unidirectional.