JPH02199949A - Data transmission system - Google Patents

Abstract

PURPOSE:To enhance the data arrival rate and to improve the transmission efficiency by dividing a data to be sent into plural local data, setting priority to each local data and sending the local data only with high priority when the utilizing rate of a communication line is high. CONSTITUTION:A data B inputted to a processing circuit 2 via an input/output circuit 1 is divided into information sets D1-Dm to set priority and they are stored in a RAM 6 together with the number of the data B and a transmission request occurrence time. Then the line busy rate is calculated from the line busy time per unit time and when the line busy rate is high, the information D2 with the most importance is sent. After the decreased in the line busy rate is awaited, all the information sets D1-Dm are sent again. Thus, the data arrival rate is increased and a common communication line is used effectively by plural communication equipments thereby improving the data transmission efficiency.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a data transmission method suitably used between communication devices in the transportation industry, such as the delivery industry.

2. Description of the Related Art In the transport and transportation industries, a configuration is used in which a plurality of communication devices share the same communication line to transmit data.

FIG. 6 is a flowchart for explaining a typical prior art data transmission operation. In step 1, when a data transmission request occurs, such as by operating the transmission button or inputting data to be transmitted, the process moves to step rm2, where it is determined whether the communication line is in use. , if so, this step rm2 is repeated, and when the communication line becomes free, data is transmitted in step n3, and the process moves to step n4.

In step n4, it is determined whether or not a confirmation signal indicating that the data has been reliably received has been returned from the communication device that received the transmitted data, and if so, the data transmission operation is terminated; otherwise, Sometimes, the process waits for a predetermined period of time in step n5 and then returns to step n5.
Return to step 2 and retransmit the data.

In this way, if another communication device interrupts and starts data transmission while a communication device is transmitting data, the transmitted data will collide and it will not be possible to receive it reliably. , after waiting for a predetermined time, retransmission is performed.

Problems to be Solved by the Invention In the prior art as described above, retransmission is repeated until the data is reliably received, regardless of the importance of the data, so if the waiting time until retransmission is the same, Problems such as retransmitted data colliding again occur, and the line usage rate, that is, the time the communication line is used per unit time, increases, whereas incoming calls that can reliably transmit data The rate decreases, and the data transmission efficiency decreases.

An object of the present invention is to provide a data transmission method that can improve data transmission efficiency and reliably transmit highly important data.

Means for Solving the Problems The present invention provides a data transmission system between communication devices in which the same communication line is shared by a plurality of communication devices.Data to be transmitted is divided into a plurality of partial data, and each partial data is setting priorities, and transmitting only partial data with a high priority when the number of communication devices using the communication line per unit time is large;
According to the present invention, a data transmission method is characterized in that when the number of communication devices using the communication line per unit time is small, even partial data with a low priority is transmitted. The data is transmitted using the same communication line.The data to be transmitted is divided into a plurality of partial data, and each partial data is assigned a priority order. When communicating, each communication device measures the usage rate of the communication line, that is, the number of communication devices that use the communication line per unit time, and when the usage rate is high, the priority is high, that is, the importance is Only the high partial data is transmitted, and when the usage rate is low, the low priority, that is, the low importance partial data is also transmitted.

Therefore, when the communication line is congested and the line usage rate is high, it is possible to reliably transmit the minimum necessary data of high importance. Furthermore, when the congestion on the communication line is eliminated and the line usage rate decreases, all data, even partial data of low importance, is transmitted. In this way, it is possible to increase the data arrival rate and improve the transmission efficiency.

Embodiment FIG. 1 is a system diagram of a wireless communication system for a delivery business using a data transmission system according to an embodiment of the present invention. Each of a plurality of automobiles that collect and deliver packages is equipped with radio RM1 to M3, and a mobile station 81 is configured. On the other hand, a radio device MO is arranged at the base station SO, and this radio device M
A central processing unit U is connected to O. Each mobile station 81
~S3 performs wireless communication with the base station SO and performs collection and delivery operations according to instructions from the base station SO.

FIG. 2 is a block diagram showing the electrical configuration of the radio device MO of the base station SO and the radio device M1 of the mobile station S1. In the mobile station S1, when data B is input from the keyboard 11, reading sensor 12, etc. and a transmission request is generated, the input data B is set by the car number setting means 13 realized by, for example, a dip switch. The mobile station S
It is derived from the input/output circuit 1 to the processing circuit 2 together with the vehicle number 1.

The processing circuit 2 converts the input data B into a plurality of pieces of information Di, D2 . . . , Dm, and sets a priority to each piece of information D1 to Drn, stores it in a random access memory (hereinafter referred to as rRAMJ) 6, and responds to the line busy signal from the OR gate 3. The information up to the given priority is transmitted from the transmitter 4 via the antenna 5. If it is not possible to transmit all the data during this data transmission, the RAM
As shown in Fig. 3 of the conclusion, all information D1 to Dm to be transmitted and management data C indicating which information has been transmitted are stored in 6, and when the line usage rate decreases. Then, all the information D1 to Dm is transmitted again. A read-only memory (hereinafter referred to as FROM) 8 is also provided in connection with the processing circuit 2, and this ROM 8 stores processing procedures for transmitting and receiving operations and the like.

Data from the base station SO received by the antenna 5 is input from the receiver 7 to the processing circuit 2. The receiver 7 derives an output to one input of the OR gate 3 when a carrier wave of the same channel is detected, and the transmitter 4
When the radio M1 is performing a transmitting operation, it delivers an output to the other input of the OR gate 3, and thus a line busy signal is derived from the OR gate 3 indicating whether the communication line is in use. Ru. Data B to be transmitted and received, transmission and reception status, etc. are transmitted from the processing circuit 2 via the input/output circuit 1.
It is output to the display device 14.

Remaining mobile station S2. S3 radio M2. M3 is the wireless t
It is configured in the same way as l1M1, and the base station SO radio M
In the radio tl1MO, O is similar to the radio M1, and corresponding parts are indicated by the same reference numerals with the suffix a.
The aforementioned central processing unit U is connected to the input/output circuit 1a.

FIG. 3 is a diagram showing the storage state of data B in the RAM 6. The RAM 6 roughly stores data B to be transmitted. i Head area F1 and the aforementioned management data C
It is composed of two areas: a management area F2 that stores . The data storage area F1 contains a plurality of data B1, B2 .・
.
It is composed of Information D1 is, for example, the customer name, that is, the name of the dealer, information D2 is the receiving number, that is, the slip number, information D3 is the receiving time, and information D4 is the address of the dealer. In addition, the management area F2 includes management data c1. c.
2. ..., C1 is stored.

Therefore, for example, when the line busy rate is high at the time when the data B1 is transmitted, the management data C1 stores that up to information D2 has been transmitted, and when the line busy rate decreases a little, the transmitted data B2 , it is stored in the management data C2 that information up to IgD4 has been transmitted.

FIG. 4 is a flowchart for explaining the data transmission operation of the wireless devices MO to M3 configured as described above. In step q1, when a data transmission request occurs due to a transmission switch being operated, etc., the process moves to step q2, where data B input to the processing circuit 2 via the input/output circuit 1 is processed in order to set the priority order. It is divided into information D1 to Dm, and along with the number and transmission request generation time of this data B, R
Stored in AM6. In step q3, the processing circuit 2
determines whether a line busy signal is derived from the OR gate 3, that is, whether the communication line is in use, and if so, repeats this step 93;
When the communication line becomes free, the process moves to step q4.

In step q4, the line busy rate is calculated from the line busy time per unit time, and when the line busy rate is small, the process moves to step q5, when it is medium, the process moves to step q6, and when it is large, the process moves to step q7. . In step q5, all the information [D1 to Dm are transmitted, in step q6, information D1 to D4 of medium importance is transmitted, and in step q
In step 7, up to information D2 with the highest degree of importance is transmitted.

From steps q5 to n7, the process moves to step q8, in which it is determined whether the confirmation signal from the base station SO has been received, and if not, the process proceeds to step q9.
After waiting for a predetermined time, the process returns to step q3 and retransmits the data.

When the confirmation signal is received in step q8, the process moves to step qlO, where the management area F2 in the RAM 6 is checked, and in step cill, it is determined whether there is any data for which all of the information D1 to Dm has not been completely transmitted. If not, the operation is terminated, and if so, the process moves to step q12, waits until the line busy rate becomes small, and then returns to step q5, where all the information D1 to
Dm is retransmitted.

In this manner, in the data transmission system according to the present invention, information in data B to be transmitted is divided into D1 to Dm in order to set priorities, and when the busy rate of the communication line is high, information with high importance is By transmitting information up to D2 and then transmitting all information 91D1 to Dm when the line busy rate decreases, it is possible to increase the data reception rate and effectively use a common communication line with multiple communication devices. data transmission efficiency can be improved.

Note that in the above embodiment, the line busy rate is medium and the information D
Even if 1 to D4 are transmitted, if the line busy rate decreases and the remaining information D5 to Drn is to be transmitted, all information D1 to Dm including the previously transmitted information D1 to D4 will be transmitted. However, as another embodiment of the present invention, it may be configured to transmit only the remaining information D5 to Dm following the data number.

FIG. 5 is a system diagram of a measurement system called a telemeter in which a data transmission method according to another embodiment of the present invention is used. In this system, multiple terminal devices 01 to G3 are
It is connected to the central processing unit U1 via a common communication line 11. Each terminal device 7G1-G3 has measurement sensors R11-R13: R21-R23; R31-R33 (
) are connected, and each terminal device 01 to G3 is connected to the central processing unit U based on the measurement result of the measurement sensor R and the busy rate of one communication line 11.
Send data to 1.

That is, for example, in the terminal device G1, when the line busy rate is small, the measurement results of all measurement sensors R11 to R13 are transmitted, and when the line busy rate is large, only the measurement results of measurement sensor R11, which is of high importance, are transmitted. or sequentially transmit the measurement results of each measurement sensor R11 to R13. Furthermore, if the measurement result is the same as the previous transmission, for example, only the terminal number is transmitted, thus reducing the data length. In this way, data transmission efficiency can be improved, and the same communication line 11
It is possible to connect a large number of terminal devices to the network, reduce the number of borrowed communication lines 11, and reduce the processing capacity of the central processing unit U1, thereby achieving cost reduction.

Effects of the Invention As described above, according to the present invention, data to be transmitted is divided into a plurality of partial data, a priority is set for each partial data, and each communication device has a high usage rate of a communication line. At times, only the high-priority, ie, highly important, partial data is transmitted, and when the usage rate is low, the low-priority, ie, less important, partial data is also transmitted, so that the communication line is congested. When the line usage rate is high, the minimum necessary data of high importance can be reliably transmitted. Additionally, when communication line congestion is resolved and the line usage rate decreases, all data, including less important partial data, can be transmitted, thereby increasing the data arrival rate and improving transmission efficiency. .

[Brief explanation of the drawing]

FIG. 1 is a system diagram of a wireless communication system using a data transmission system according to an embodiment of the present invention, and FIG. 2 shows an electrical configuration of a radio device MO of a base station SO and a radio device M1 of a mobile station S1. 3 is a diagram showing the storage state of data B in the RAM 6, FIG. 4 is a flowchart for explaining the data transmission operation, and FIG. 5 is a diagram showing the data transmission method used in another embodiment of the present invention. FIG. 6 is a flowchart for explaining the data transmission operation of the prior art. 1.1a...input/output circuit, 2,2a...processing circuit,
3.3a・-OR gate, 4.4a-=transmitter, 6゜6
a...RAM, 7,7a...receiver, Fl...data storage area, F2...management area, 61-G3...
Terminal device, MO to M3... Radio device, R... Measurement sensor, SO... Base station, 81 to S3... Mobile station, U,
Ul...Central processing unit agent Patent attorney Number of strokes

Claims (1)

[Claims] In a data transmission method between communication devices in which the same communication line is shared by a plurality of communication devices, data to be transmitted is divided into a plurality of partial data and a priority is assigned to each partial data. setting, and when the number of communication devices using the communication line per unit time is large, transmitting only partial data with a high priority,
A data transmission method characterized in that when the number of communication devices using the communication line per unit time is small, even partial data with a low priority is transmitted.