JPH11355466A - Communication system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To immediately execute new transmission by allowing a center device or a terminal device which transmits a call set message that sets notification information of the opposite device to start disconnection restoration processing before the opposite device performs line connection. SOLUTION: A center device 1 sets a request for meter information from a center terminal 5 to a user.user information element of a 'call set' message (a) to be transmitted and transmits it to a terminal device 2A. An ISDN public line 3 returns a 'call set receiving' message (b) to the device 1 and transmits the message (a) to the device 2A. The device 1 transmits a 'disconnection' message (c) to the line 3 and completes disconnection restoration processing with the exchange of a 'release' message (d) and a 'release completion' message (e). The line 3 completes disconnection restoration processing with the exchange of a 'release' message (f) and a 'release completion' message (g) and also the device 2A completes it with the exchange of a 'release' message (k) and a 'release completion' message (m).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication system for a terminal device such as a meter-reader or equipment having a communication function to communicate with a center device via an ISDN public line.

[0002]

2. Description of the Related Art An automatic meter reading of an energy supply management device (for example, a gas meter, a water meter, an electric power meter, etc.) as a terminal device from a center device using a telephone network, a notification of gas leak to the center device, 2. Description of the Related Art Telemeter systems for performing trouble reports and remote diagnosis of equipment are becoming widespread.

For example, in a city gas meter, 300 bits
/ S start-stop synchronous communication system has been standardized in the industry.
U.T. Recommendation V. By performing modulation and demodulation based on 21 and converting it into an analog signal, communication with a center device installed in a gas company or a security company is performed using a public telephone line.

[0004] Furthermore, ISDN public lines have begun to spread, and introduction to general households for accessing personal computer communication and the Internet has also become active. ISD
On the N line, frame synchronous communication is performed.
Data communication can be performed by circuit switching communication or packet communication using a 4 kbit / s B channel, and packet communication using a 16 kbit / s D channel.

FIG. 4 is a system block diagram showing an embodiment of a general ISDN telemeter system, and FIGS. 5 (a) and 5 (b) are block diagrams showing one configuration example of a terminal device and a center device in FIG. is there.

As shown in FIG. 4, one center device 1
And a plurality of terminal devices 2A, 2B arranged in each customer house,
2C, 2D and 2E are connected via the ISDN public line 3. The center device 1 is shown in FIG.
As shown in FIG. 5, a center-side network control device 4 for performing ISDN communication control including data transmission / reception and a center terminal 5 such as a personal computer for managing each terminal device are provided. As shown in FIG. 1, the terminal network controller 6 performs ISDN communication control including data transmission and reception, and a terminal 7 such as a gas meter.

As a method of transmitting data in a remote management system using an ISDN public line, a method of adding data to user / user information of a D-channel call setup message is disclosed in Japanese Patent Laid-Open No. 9-205491. . However, the amount of data that can be transmitted as user information at one time is 128 octets according to ISDN regulations (NTT Technical Reference Material INS Net Service Interface Volume 3).

In this method, a communication procedure in which the center device 1 collects meter information from the terminal device 2A will be described with reference to a sequence chart of FIG. In the center device 1, a request for meter information from the center terminal 5 is set in the user / user information element of the "call setting" message a transmitted from the center side network control device 4, and the call is transmitted.

[0009] In the ISDN public line 3, "call setting acceptance"
While returning the message b to the center device 1,
A "call setting" message a is sent to the terminal device 2A. The terminal side network control device 6 of the terminal device 2A reads the request for meter information from the user / user information element of the received “call setting” message “a” and transmits a “release complete” message “c” to the ISDN public line 3. Public line 3
Sends a “disconnect” message d to the center device 1 and completes the disconnection recovery process of the center device 1 by exchanging the “release” message e and the “release complete” message f.

[0010] Then, the terminal side network control device 6 receiving the request for the meter information reads the meter information from the terminal 7 and sets the meter information in the user / user information element of the "call setting" message g. Send a call to address 1. In the ISDN public line 3, a "call setting accepted" message h is returned to the terminal device 2A, and a "call setting" message g is sent to the center device 1.

The center-side network control device 4 of the center device 1
Then, the meter information is read from the user / user information element of the received "call setting" message g, and "release complete"
When message i is sent to ISDN public line 3, IS
The DN public line 3 sends the "disconnect" message j to the terminal device 2A.
, And the disconnection restoration process of the terminal device 2A is completed by exchanging the “release” message k and the “release complete” message m. Then, the center-side network control device 4 that has received the meter information sends the meter information to the center terminal 5, and the center terminal 5 can check the meter information.

However, in ISDN, eight communication terminals can be connected at the same time, so that the ISDN public line uses other than the “release complete” message received as a response message of the terminal device to the “call setup” message. Since the communication terminal may return a "call" or "response" message, it waits unconditionally for 6 seconds after sending the "call setup" message (NTT Technical Reference INS Net Service Interface Volume 3), Thereafter, a "disconnect" message is sent to the center device.

Further, as shown in FIG. 7, a general sequence at the time of restoration of disconnection of a communication terminal waits for a response of a "release" message d in response to a "disconnection" message a, and "release complete".
This is completed by sending the message e. At this time, the waiting time for receiving the “release” message d from the transmission of the “disconnect” message a is within 30 seconds (NTT Technical Reference INS
The third part of the Internet service interface).

[0014]

The following problems are encountered when a communication system is realized using the above-described method.

(1) The response to the calling side in response to the disconnection recovery processing from the called side is 6 seconds or more, so it is necessary to wait for 6 seconds or more even when transmitting from the same side continuously.

(2) When the disconnection recovery process is started by sending a “disconnect” message, a “release” message
Because there is a possibility of waiting for seconds, a new call may not be made immediately.

(3) When disconnection recovery processing is performed before line connection from the calling side, it is not known whether or not there is a communication terminal capable of communicating with the other side.

[0018]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a system including a center device and a plurality of terminal devices connected via an ISDN public line, and a notification to a partner device. The center device or the terminal device that has transmitted the “call setting” message in which the information has been set starts disconnection recovery processing before the other device performs the line connection, and transmits the notification information to the other device without performing the line connection. Communication is performed by transmitting only the set “call setting” message.

According to the above-mentioned invention, a new call can be immediately made in the ISDN public line in order to start the disconnection recovery processing from the calling side without disconnecting the disconnection of the called side without waiting time. .

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention comprises a center device and a plurality of terminal devices connected via an ISDN public line, and transmits a "call setting" message in which notification information to a partner device is set. The center device or the terminal device starts the disconnection recovery process before the partner device connects the line.

In order to start the disconnection recovery process from the calling side, the ISDN public line can immediately perform a new call in order to perform the disconnection recovery of the called side without waiting time. Further, the disconnection recovery processing from the calling side is started by transmitting a “release” message.
Since the completion time of the disconnection recovery process on the transmitting side is earlier, a new transmission can be performed earlier.

Further, the disconnection recovery processing from the calling side is started after the reception of the "call" message. Since the "calling" message sent from the called side can be confirmed on the calling side, it can be seen that there is a communication terminal that can communicate with the other side.

[0023]

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

(Embodiment 1) A system block diagram showing an embodiment of an automatic meter reading system according to Embodiment 1 of the present invention and a block diagram showing an example of a terminal-side device and a center-side device are shown in FIGS. FIG. FIG. 1 is a sequence chart showing an operation sequence between the center device 1 and the terminal device 2A in the present embodiment. In the above configuration, a communication procedure for collecting meter information will be described with reference to a sequence chart of FIG.

In the center device 1, a request for meter information from the center terminal 5 is set in the user / user information element of the "call setting" message a transmitted from the center side network control device 4 and transmitted to the terminal device 2A. I do. ISDN
In the public line 3, the "call setting accepted" message b is returned to the center device 1, and the "call setting" message a
To the terminal device 2A. In the center device 1, IS
Upon receiving the "call setting accepted" message b from the DN public line 3, the "disconnect" message c is sent to the ISDN public line 3.
And the "release" message d and the "release complete" message e are exchanged to complete the disconnection recovery process. The terminal side network control device 6 of the terminal device 2A reads the request for the meter information from the user / user information element of the received “call setting” message a.

The ISDN public line 3 sends a "disconnect" message c from the center device 1 to the terminal device 2A. When the terminal device 2A receives the "disconnect" message c,
The disconnection recovery processing is completed by exchanging the “release” message f and the “release complete” message g. Then, the terminal-side network control device 6 that has received the request for the meter information reads the meter information from the terminal 7 and outputs a “call setting” message h.
The meter information is set in the user / user information element of (1), and the call is transmitted to the center device 1.

In the ISDN public line 3, "call setting reception"
The message i is returned to the terminal device 2A, and the “call setting” message h is sent to the center device 1. When the terminal device 2A receives the “call setting acceptance” message i from the ISDN public line 3, the “disconnection” message j
Is transmitted to the ISDN public line 3, and a "release" message k
The disconnection recovery process is completed by exchanging the message "release complete" with the message m.

Center-side network control device 4 of center device 1
Then, the meter information is read from the user / user information element of the received "call setting" message h. The ISDN public line 3 sends a “disconnect” message j from the terminal device 2A to the center device 1, and the center device 1
When the message j is received, the disconnection recovery processing is completed by exchanging the “release” message p and the “release complete” message q.

[0029] Then, the center-side network control device 4 which has received the meter information sends the meter information to the center terminal 5, and the center terminal 5 can check the meter information. In addition, if the request for meter information and the meter information are set in the calling sub-address information element and the destination sub-address information element of the “call setting” message in addition to the user / user information element, the notification information can be confirmed on the receiving side. The same effect can be obtained.

(Embodiment 2) A system block diagram showing an embodiment of an automatic meter reading system according to Embodiment 2 of the present invention and a block diagram showing an example of a terminal-side device and a center-side device are shown in FIGS. FIG. FIG. 2 is a sequence chart showing an operation sequence between the center device 1 and the terminal device 2A in the present embodiment. The difference between the second embodiment of the present invention and the first embodiment is that the center-side network control device 4 and the terminal-side network control device 6 transmit a “release” message at the start of the disconnection recovery process.

In the above configuration, a communication procedure for collecting meter information will be described with reference to a sequence chart of FIG. In the center device 1, the request for the meter information from the center terminal 5 is set in the user / user information element of the "call setting" message a transmitted from the center side network control device 4, and the call is transmitted to the terminal device 2A.

In the ISDN public line 3, "call setting reception"
While returning the message b to the center device 1,
A "call setting" message a is sent to the terminal device 2A. When the center apparatus 1 receives the "call setting acceptance" message b from the ISDN public line 3, it sends a "release" message c to the ISDN public line 3, and the ISDN public line 3
The disconnection recovery processing is completed by receiving the “release complete” message d from the server.

In the terminal side network control device 6 of the terminal device 2A,
The request for meter information is read from the user / user information element of the received "call setting" message a. Upon receiving the “release” message c from the center device 1, the ISDN public line 3 sends a “disconnect” message e to the terminal device 2A, and the terminal device 2A receives the “disconnect” message e when receiving the “release” message e. The disconnection recovery processing is completed by exchanging the message “f” with the “release complete” message g.

Then, the terminal side network control device 6 receiving the request for the meter information reads the meter information from the terminal 7, sets the meter information in the user / user information element of the "call setting" message h, and sets the center device. Send a call to address 1. The ISDN public line 3 returns a “call setting accepted” message i to the terminal device 2A and sends a “call setting” message h to the center device 1.

When the terminal device 2A receives the "call setting accepted" message i from the ISDN public line 3, it sends a "release" message j to the ISDN public line 3,
The disconnection recovery processing is completed by receiving the “release complete” message k from the DN public line 3.

The center-side network control device 4 of the center device 1
Then, the meter information is read from the user / user information element of the received "call setting" message h. Upon receiving the “release” message j from the terminal device 2A, the ISDN public line 3 sends a “disconnect” message m to the center device 1, and the center device 1 receives the “release” message m and receives a “release” message. The disconnection recovery process is completed by exchanging the message “n” and the “release complete” message p. Then, the center-side network control device 4 receiving the meter information
Transmits the meter information to the center terminal 5, and the center terminal 5 can check the meter information.

(Embodiment 3) A system block diagram showing an embodiment of an automatic meter reading system according to Embodiment 3 of the present invention and a block diagram showing an example of a terminal-side device and a center-side device are shown in FIGS. FIG. FIG. 3 is a sequence chart showing an operation sequence between the center device 1 and the terminal device 2A in the present embodiment. The difference between the third embodiment of the present invention and the first embodiment is that the center-side network controller 4 and the terminal-side network controller 6 return a "call" message in response to the "call setup" message, Is to start the disconnection recovery process after confirming the "call" message.

In the above configuration, a communication procedure for collecting meter information will be described with reference to a sequence chart of FIG.

In the center device 1, a request for meter information from the center terminal 5 is set in the user / user information element of the "call setting" message a transmitted from the center side network control device 4 and transmitted to the terminal device 2A. I do. ISDN
In the public line 3, the "call setting accepted" message b is returned to the center device 1, and the "call setting" message a
To the terminal device 2A. The terminal-side network control device 6 of the terminal device 2A reads the request for meter information from the user / user information element of the received “call setting” message a, and sends out a “call” message c to the ISDN public line 3. In the ISDN public line 3, a "call" message c
To the center device 1. In the center device 1, I
When the "call" message c from the SDN public line 3 is received, a "disconnect" message d is sent to the ISDN public line, and a "release" message e and a "release complete" message f
The disconnection recovery process is completed by the exchange of the information. ISDN
The public line 3 sends a "disconnect" message d from the center device 1 to the terminal device 2A. When the terminal device 2A receives the "disconnect" message d, the "release" message g
The disconnection recovery processing is completed by exchanging the message "release complete" h.

Then, the terminal side network control device 6 receiving the request for the meter information reads the meter information from the terminal 7, sets the meter information in the user / user information element of the "call setting" message i, and Send a call to address 1.

In ISDN public line 3, "call setting acceptance"
A message j is returned to the terminal device 2A, and a “call setting” message i is sent to the center device 1.

Center-side network control device 4 of center device 1
Then, the meter information is read from the user / user information element of the received "call setting" message i, and the "call" message k is sent to the ISDN public line 3. The ISDN public line 3 sends a "call" message k to the terminal device 2A. Upon receiving the "call" message k from the ISDN public line 3, the terminal device 2A sends a "disconnect" message m to the ISDN public line 3, and disconnects by exchanging the "release" message n and the "release complete" message p. Complete the recovery process. The ISDN public line 3 sends a "disconnect" message m from the terminal device 2A to the center device 1. When the center device 1 receives the "disconnect" message m, the center device 1 sends a "release" message q and a "release complete" message r. The disconnection recovery process is completed by the exchange.
Then, the center-side network control device 4 that has received the meter information sends the meter information to the center terminal 5, and the center terminal 5 can check the meter information.

[0043]

According to the telemeter system of the present invention, the following effects can be obtained.

(1) Since the disconnection recovery processing is started from the transmitting side, the disconnection recovery processing of the receiving side can be performed promptly, so that it is not necessary to wait for a long time even if the transmission is continuously performed from the same side.

(2) Since the disconnection recovery processing is started by sending the “release” message, there is no waiting time of up to 30 seconds from the sending of the “disconnect” message to the reception of the “release” message, so that a new call is immediately sent. Can be.

(3) In order to return the "call" message in response to the "call setup" message, even when performing the disconnection recovery processing before connecting the line from the calling side, receiving the "call" message allows the other party to receive the "call" message. It can be seen that there is a communication terminal that can communicate.

[Brief description of the drawings]

FIG. 1 is a sequence chart of a communication procedure in a communication system according to a first embodiment of the present invention.

FIG. 2 is a sequence chart of a communication procedure in the communication system according to the second embodiment of the present invention.

FIG. 3 is a sequence chart of a communication procedure in a communication system according to a third embodiment of the present invention.

FIG. 4 is a system block diagram of a general ISDN telemeter system.

FIG. 5A is a block diagram illustrating a configuration example of a general center device; FIG. 5B is a block diagram illustrating a configuration example of a general terminal device;

FIG. 6 is a sequence chart of a communication procedure using a conventional user / user information element.

FIG. 7 is a sequence chart of a general disconnection recovery procedure.

[Explanation of symbols]

 1 center device 2 terminal device 3 ISDN public line 4 center side network control device 5 center terminal 6 terminal side network control device 7 terminal

Claims (3)

[Claims] 1. A center device or a terminal device comprising a center device connected via an ISDN public line and a plurality of terminal devices, and transmitting a "call setting" message in which notification information to a partner device is set. Is a communication system, wherein a disconnection recovery process is started before a partner device performs a line connection. 2. The communication system according to claim 1, wherein the disconnection recovery processing is started by sending a “release” message. 3. The communication system according to claim 1, wherein the disconnection recovery processing is started after receiving the “call” message.