JPH08321895A - Communication system - Google Patents

Abstract

PURPOSE: To reduce a communication cost for a retrieving processing in communication between an on-vehicle terminal and an information center. CONSTITUTION: A retrieving command is transmitted from a mobile telephone set of a vehicle 100 to the information service center 104. The information service center 104 predicts a processing time for the retrieving processing and when the time is not less than a prescribed value, transmits a line disconnection request to the on-vehicle terminal. After the retrieving processing is finished, the information service center 104 calls the on-vehicle terminal to reconnect the line and transmits the result of the retrieval to the on-vehicle terminal.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to communication systems, and more particularly to reducing communication costs.

[0002]

2. Description of the Related Art In recent years, there has been proposed a communication system in which a vehicle uses an automobile telephone to cause an information center to perform various search processes and transmit the results to the vehicle. However, when performing such a search process, there is a problem that the communication cost increases because the process takes time depending on the search condition. Therefore, for example, as disclosed in Japanese Patent Laid-Open No. 6-6349, a cost calculation device calculates a communication level and a communication cost corresponding to the communication level and displays the communication cost on a display device. A configuration for determining and communicating is disclosed.

[0003]

However, when the above-mentioned prior art is applied to a car telephone, for example, it is difficult for the operator (driver) to judge by looking at the displayed communication cost, and it is possible to make an accurate judgment. It is not uncommon to make incorrect choices.

Even if the operator selects a route that he / she considers to be optimal, the information center displays "searching" during the information search, and the communication line remains connected during the search, so the search processing is performed. There is a problem that the line fee is wasted only for the time required for.

Incidentally, conventionally, in order to shorten the communication time, the line is connected, and then a search command which is predetermined between the terminal and the information center is transmitted from the terminal to disconnect the line once, and the search processing is completed. Then, a communication method called so-called asynchronous mode communication in which a line is connected to the terminal from the information center side and the search result is transmitted is also considered, but since the line is connected at least twice, the connection is started. There is a problem that the required time and the time from the connection to the actual start of communication are doubled, and if the time required for the information center search processing is shorter than these times, the communication cost is rather increased.

The present invention has been made in view of the above problems of the prior art, and an object thereof is to reduce the communication cost and to provide a communication system particularly suitable for a vehicle-mounted terminal.

[0007]

In order to achieve the above object, the present invention processes information based on a communication terminal and a command transmitted from the communication terminal, and transmits the processing result to the communication terminal. In a communication system including a communication center, an arithmetic means for evaluating a communication cost required for the processing, and when the communication cost is equal to or more than a predetermined value, communicates with the communication terminal until the processing result can be transmitted to the communication terminal. And a communication control means for temporarily disconnecting communication between the centers.

In order to achieve the above-mentioned object, the present invention is a car telephone in which the communication terminal is mounted in a vehicle, the communication control means is provided in the communication center, and the communication control means is the communication. If the cost is equal to or higher than a predetermined value, the line with the car phone is temporarily disconnected, and when the process result reaches a state where it can be sent, the car phone is called to reconnect the line and the process result is sent. After that, the line is disconnected.

Further, in order to achieve the above object, the present invention is characterized in that the communication control means selects a type of a line for performing the line reconnection according to the communication cost.

[0010]

In the present invention, instead of presenting the communication cost to the operator and prompting the operator to select it as in the prior art, the information center automatically evaluates the communication cost. Disconnect the line temporarily and shift to asynchronous mode. Thereby, it is possible to automatically reduce the communication cost without depending on the judgment of the operator.

When the line is temporarily disconnected, it is preferable to reconnect from the information center side. This is because it is complicated to reconnect from the terminal side. Then, after the re-connected information center side transmits the processing result and automatically disconnects the line, the processing result can be acquired without performing any operation on the in-vehicle terminal (car phone) side even after shifting to the asynchronous mode. .

Further, according to the present invention, when the communication cost is equal to or higher than a predetermined value and the line is temporarily disconnected and then reconnected from the information center side, the type of the line is selected according to the communication cost and the processing result is selected. Reply the result on the line. Thereby, it is possible to further reduce the communication cost.

[0013]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a system configuration diagram of this embodiment. A communication terminal, which will be described later, is mounted on the vehicle 100, and the information providing center 10 is provided via the communication carrier 102.
4. Communicate with 4. The information providing center 104 is connected to information providers (IP) 106 and 108 having databases,
The search process requested by the in-vehicle terminal is executed, and the search result is returned.

FIG. 2 shows the structure of a communication terminal mounted on the vehicle 100. In the command input device 10, a command in which the information providing center 104 and its processing content are agreed in advance is input. The electronic control unit (ECU) 12 transmits the input command to the information providing center 104 using the car telephone 14. Then, when the search result corresponding to this command is transmitted, the ECU 12 causes the display 16
The result is displayed on. The command input device 10 can be configured by the touch switch displayed on the display 16. In this case, the command input device and the display are integrated. Further, the ECU 12 in this embodiment has a function of controlling the car telephone 14 to forcibly disconnect the line when a line disconnection request is received from the information providing center 104. In what case the line disconnection request is transmitted will be described later.

FIG. 3 shows the structure of the information providing center 104. The computer 22 communicates with the communication carrier 102 via the communication control device 20, inputs a search command from the vehicle-mounted terminal, and interprets the content of the command. Then, the IP 106 or the IP is transmitted via the communication control device 24.
A search instruction is sent to 108, and the obtained search result is transmitted again to the vehicle-mounted terminal via the communication control device 20. Although the communication control devices 20 and 24 are individually provided in this way in the present embodiment, a single communication control device can be used for communication carriers and IPs.
It is also possible to communicate with.

Further, when returning the search result to the vehicle-mounted terminal, the computer 22 first statistically evaluates the processing time as the communication cost required to execute the command transmitted from the vehicle-mounted terminal, and the processing time is predetermined. When it is determined that the value is equal to or more than the value, a disconnection request for the line is transmitted to the vehicle-mounted terminal. This processing time is calculated by multiplying the statistical average processing time of each processing command stored in the memory 23 by the load degree of the information providing center 104 (load degree ≧ 1.0) as a weight. That is,

## EQU00001 ## Processing time (communication cost) = average processing time * load degree. This expression means that the processing time is expected to exceed the average processing time when the load of the information providing center 104 is high, and it can be executed in the average processing time when the load is low.

The average processing time is calculated as follows. That is, initially, a certain reference value (when there is no load) is set, and when a certain command is used, the execution start to end is monitored and stored in a histogram format. Then, each time a command is transmitted from many vehicles, the time required for the processing is stored, and the final average processing time is calculated from the obtained histogram and stored in the memory 23. Therefore, this average processing time is not fixed and is updated every time a command is used. The load level is an index for checking how many commands have been used per unit time, and indicates the load status of the processing of the information providing center 104, and is calculated as follows.

[0019]

## EQU00002 ## Load level = (number of commands per unit time / maximum number of commands that can be processed) +1 The in-vehicle terminal and the information providing center 104 of this embodiment have the above-described configuration. Also, the processing in the information providing center 104 will be described in detail.

Processing of Information Providing Center FIGS. 4 and 5 are flowcharts of processing in the information providing center 104. First, in FIG. 4, when the command transmitted from the vehicle-mounted terminal is acquired (S101), the computer 22 of the information providing center 104 calculates the processing time for the acquired command according to the evaluation formula (S102).
After the expected processing time is calculated, the computer 22 determines whether the processing time is within a specified time which is a predetermined value (S103). The specified time is set according to each communication path,
For example, in a digital car telephone with a communication speed of 2400 bps, it takes about 20 seconds to set the modem until communication can be actually performed after the line is connected. In this case, 20 seconds is set as the specified time. Then, when it is determined that the processing time is within the specified time, a mode notification is transmitted to the in-vehicle terminal that the processing is to be performed in the synchronous mode in which the line is still connected and the search result is returned (S104). After this mode notification, the information providing center 104 instructs the IP 106 or 108 to perform a search process corresponding to the command (S10
5) The search result is returned to the vehicle-mounted terminal (S106).

On the other hand, if it is determined that the processing time exceeds the specified time, the fact that the processing is to be executed in the asynchronous mode for disconnecting the temporary line is notified (S107), and the calculated processing time is sent to the vehicle-mounted terminal. After notifying (S108), a line disconnection request is transmitted (S109). On the vehicle-mounted terminal side that has received this line disconnection request, the ECU 12 controls the car telephone 14 to temporarily disconnect the line as described above. This allows
It is possible to reduce unnecessary communication costs during the search processing.

FIG. 5 is a processing flowchart in the information providing center 104 after operating in the asynchronous mode. When the search process ends, the information providing center 104 performs a process of calling the in-vehicle terminal and reconnecting the line (S201). After connecting, the search result is returned to the in-vehicle terminal (S20
2) After the reply, the process of disconnecting the line is performed (S203).
That is, after the in-vehicle terminal disconnects the line by transmitting the line disconnection request in the process of S109, the information providing center 104
From the side, the line is connected to the in-vehicle terminal, the search result is returned, and the line is disconnected at the information providing center 104 side. Therefore, after disconnecting the temporary line, the operator on the in-vehicle terminal side can obtain the inspection result without any operation.

Processing of In-Vehicle Terminal FIG. 6 shows a processing flowchart of the in-vehicle terminal. First, when the operator selects a command and inputs it to the command input device 10 (S301), the ECU 12 operates the automobile telephone 14 to connect the line to the information providing center 104 (S302), and transmits the input command. (S
303). Then, the process shifts to a waiting state for receiving a mode notification from the information providing center 104 (S304). When a mode notification is received from the information providing center 104 in this state,
It is determined whether the mode is the synchronous mode or the asynchronous mode, and when the mode is the synchronous mode, the line is maintained as it is and the search result is received (S305). When the search result is received, the ECU 12 disconnects the line and ends the processing of the command (S306).

On the other hand, when the received mode is the asynchronous mode, the processing time transmitted from the information providing center 104 is further received and displayed on the display 16 (S307). When a line disconnection request is received (S
308), the ECU 12 temporarily disconnects the line (S30
9) Wait for a call from the information providing center 104 side. When the line is reconnected from the information providing center 104 side (S31
0), the transmitted search result is received (S311). After receiving, the ECU 12 does not perform the line disconnection process. This is because, in this case, the line is disconnected on the information providing center 104 side as described above.

As described above, in this embodiment, the communication cost required for command processing is evaluated, and the asynchronous mode, that is, the temporary line is disconnected only when the communication cost is determined to be equal to or more than the predetermined value,
When the search process is completed and the search result can be returned, the line is connected again and the process result is sent, so the operator is not bothered with the time during the search and the communication cost is reduced. Can be achieved.

Further, in the present embodiment, when the processing time as the communication cost exceeds a predetermined value, the line is temporarily interrupted and then the same line is reconnected. However, depending on the processing command, the communication speed may be higher. Reconnect using the line
The communication cost may be lower if the search result is returned.
Therefore, the line for reconnection is appropriately switched according to the communication cost (for example, 2400 bps to 9600 bps).
It is also possible to have a configuration. Specifically, after the computer 22 calculates the communication cost, the line in which the communication cost can be set to the lowest in the process of S201 is selected and connected to the in-vehicle terminal. FIG. 7 shows a configuration example in the case of selecting a line in this way. A line selecting means is provided in the information center 104, and a plurality of lines (300 bps in the figure, 1
200bps, 2400bps, 9600bps, 14
The line with the lowest communication cost is selected from the 5 types (400 bps) and transmitted to the terminal. When reconnecting to the terminal, which access point 101 to select can be determined from the telephone number of the terminal requesting the search. As a method to select the line with the lowest communication cost, first measure the negotiation time t0 of the modem when the terminal requests a search, and use each leased line based on the amount of data in the search result. Communication time t1 (300 bps), t2 expected when
(1200 bps), t3 (2400 bps), t4
(9600 bps) and t5 (14400 bps) are calculated. Then, the total communication time obtained by adding the negotiation time t0 with the modem to these times is converted into a charge (the conversion coefficient may be stored as a table in advance), and the five types of lines are The line with the lowest price from is the reconnection line. In this case, it may be preferable to notify the processing time in S108 and, at the same time, notify the type of line for reconnection.

[0027]

As described above, according to the present invention, the communication cost can be reduced, and the operator can be relieved from having to look at the terminal until the processing result is returned.

[Brief description of drawings]

FIG. 1 is a system configuration diagram of an embodiment of the present invention.

FIG. 2 is a configuration block diagram of the vehicle-mounted terminal according to the embodiment of this invention.

FIG. 3 is a configuration block diagram of an information providing center according to the embodiment of this invention.

FIG. 4 is a processing flowchart of an information providing center according to the embodiment of this invention.

FIG. 5 is a processing flowchart of the information providing center according to the embodiment of this invention.

FIG. 6 is a processing flowchart of the vehicle-mounted terminal according to the embodiment of this invention.

FIG. 7 is a configuration diagram of another embodiment of the present invention.

[Explanation of symbols]

10 command input device, 12 ECU, 14 car telephone, 16 display, 100 vehicle, 104 information providing center.

Claims (3)

[Claims] 1. A communication system including a communication terminal and a communication center which processes information based on a command transmitted from the communication terminal and transmits a processing result to the communication terminal, wherein a communication cost required for the processing is evaluated. And a communication control means for temporarily disconnecting the communication between the communication terminal and the communication center until the processing result reaches a state in which the processing result can be transmitted to the communication terminal when the communication cost is equal to or more than a predetermined value. A communication system characterized by. 2. The communication system according to claim 1, wherein the communication terminal is a car telephone mounted in a vehicle, the communication control means is provided in the communication center, and the communication control means has a predetermined communication cost. When the value is equal to or more than the value, the line with the car telephone is temporarily disconnected, and when the process result reaches a state where it can be transmitted, the car telephone is called to reconnect the line, and after the process result is transmitted, the line is transmitted. A communication system characterized by disconnecting. 3. The communication system according to claim 2, wherein the communication control means selects a type of line for performing the line reconnection according to the communication cost.