JP3500394B2 - Communications system - Google Patents

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 connecting a terminal-side communication device and a center-side communication device through respective exchanges on the terminal side and the center side and a telephone line.

[0002]

2. Description of the Related Art In a conventional communication system of this type,
When communicating with the communication device on the center side by transmission from the communication device on the terminal side, generally, a communication sequence as shown in FIG. 10 is executed.

That is, first, in response to a call from the terminal-side communication equipment, the center-side switching center reverses the polarities of L1 and L2 of the center-side communication equipment and the line-terminal equipment of the center-side communication equipment. Send a ringing signal such as a ringer.

As a result, when the line terminal device of the center side communication device goes off-hook (response signal), the center side switching center repolarizes the polarities of L1 and L2 of the line terminal device of the center side communication device.

As a result, the line terminal equipment of the center side communication equipment sends a data transmission request signal to the center side exchange. As a result, the center-side communication device and the terminal-side communication device are connected, and mutual data communication is started. In this data communication, self-identification information (ID) is added to each of the data sent from the terminal side communication device.

[0006]

However, the above-mentioned conventional communication system has the following disadvantages, and there is room for improvement.

In data communication between the center-side communication device and the terminal-side communication device, in order to allow the center-side communication device to identify the terminal-side communication device, self-identification information is added to all data transmitted from the terminal-side communication device. I am trying to add one by one. In such a method, the amount of data transmitted from the terminal-side communication device increases, so that the communication time is unnecessarily lengthened and the communication cost is inevitably increased.

In a situation in which data is transmitted from the center-side communication device before data transmission from the terminal-side communication device, the data transmitted from the center-side communication device has to be constant at all times. Even if the communication device supports protocols related to various communication modes so that it can communicate with various terminal-side communication devices having different communication modes, the terminal side does not work under the above-mentioned circumstances. It may not be possible to respond properly depending on the type of communication mode of the communication device.

It may happen that communication between the center-side communication device and the terminal-side communication device cannot be normally terminated. In addition,
The signal attenuation characteristics from the center-side switching center to the center-side communication equipment may vary in size depending on the conditions at the time of construction, but the above-mentioned failure may occur under the construction conditions at which the signal attenuation characteristics deteriorate. When such a communication failure occurs, the signal signal of the data sent from the center-side communication device is recognized by recognizing the signal attenuation characteristics described above in order to prevent the same failure from being repeated when receiving a call again from the failed party. It suffices if the level can be adjusted, or the receiving sensitivity can be adjusted before the communication device on the center side receives the data given from the switching center on the center side. It is pointed out that it is easy to repeat the same mistake.

Therefore, it is a main object of the present invention to reduce the amount of data sent from a terminal-side communication device in a communication system so that the communication time can be shortened.

[0011]

By the way, in recent years, when communicating with a center side communication device by making a call from a terminal side communication device, the center side switching center assigns a calling telephone number, that is, a calling telephone number to the center side communication device. It is conceivable to notify the calling telephone number of sending out, and this calling telephone number notification is used in the present invention.

The present invention is configured as follows in a communication system in which a terminal-side communication device and a center-side communication device are connected via each of the terminal-side and center-side switching stations and a telephone line.

In the first communication system of the present invention, the center-side switching center sends a calling telephone number to the center-side communication device when the center-side communication device communicates with the center-side communication device. , and the center side communication device, intended to support the protocols for various communications, and, when receiving the calling telephone number given from the center side switching center, and a terminal side communication device based on the calling telephone number It recognizes the type of communication form and sends and receives data via the protocol of the recognized type of communication form.
Are those, the center-side exchange or al onset Shin phone number is given, et al.
The terminal side communication device, the terminal side communication device
Also requests data transmission without adding self-identification information . Also, in the second communication system of the present invention, when the center-side switching center communicates with the center-side communication device by making a call from the terminal-side communication device, whether the center-side switching device sends a calling telephone number to the center-side communication device, Alternatively, it is performed by selecting whether to send an activation signal to the center-side communication device without sending the calling telephone number. The center-side communication device supports various communication protocols, and , when receiving the calling telephone number given from the center side switching center, it recognizes the type of communication mode between the terminal side communication device based on the calling telephone number, via a protocol in recognized types of communication forms Sending and receiving data
In addition to performing, or center side switching center et onset Shin Phone
When a given, to the terminal side communication device, the terminal
While sending a signal requesting the added decoction over data traffic, such self-identifying information from the side communications device, when the start signal is given rather than the calling telephone number from the center side switching center, to the terminal side communication device Self-identification information from the terminal side communication device.
It is assumed that a signal requesting data transmission added with is transmitted.

In the third communication system of the present invention, the center-side switching center detects the telephone number of the terminal-side communication device when communicating with the center-side communication device by transmitting from the terminal-side communication device, Means for determining whether or not to send the originating telephone number to the center-side communication device based on the detected telephone number, and a start signal, the originating telephone number, and a calling signal for the center-side communication device based on the determination result. Is transmitted at a predetermined timing, the center-side communication device supports various communication-related protocols, and when it receives the calling telephone number given from the center-side switching center, the calling telephone number recognizes the type of communication mode between the terminal side communication device based on the item, in addition to transmitting and receiving data through the protocol in recognized types of communication form, center Means for determining the presence or absence of the reception of the calling telephone number from the switching center, the determination result in to the terminal side communication device based on adding self identification information such brewing over data transfer requirements <br/> signal to seek main <br/> transmission of and data obtained by adding self-identification information and means for exiting feed selects either of the signals to be determined. Further, in the fourth communication system of the present invention, the center-side switching center sends a calling telephone number to the center-side communication device when communicating with the center-side communication device by calling from the terminal-side communication device. There, the center-side communication device, when receiving the calling telephone number from the center side switching center to the terminal side communication device, a signal to request that does not add its own identification information when transmitting data The terminal-side communication device is supposed to transmit the data to which the self-identification information is not added to the center-side communication device in response to the reception of the request signal.

In the fifth communication system of the present invention, when the center-side switching center communicates with the center-side communication device by making a call from the terminal-side communication device, does the center-side switching device send a calling telephone number to the center-side communication device? , Or whether to send an activation signal to the center-side communication device without sending the calling phone number. The center-side communication device receives the calling phone number from the center-side switching center. In this case, the self-identification information when sending data to the terminal side communication device
The terminal-side communication device transmits data to which the self-identification information is not added to the center-side communication device in response to the reception of the request signal, while the center-side communication device When a start signal is received from the center-side switching center, the terminal-side communication device sends a signal requesting the terminal-side communication device to transmit data with self-identification information, and the terminal-side communication device The device is supposed to transmit the data with the self-identification information to the center side communication device in response to the reception of the request signal. Also,
In the sixth communication system of the present invention, the center side switching center is
A means for detecting the telephone number of the terminal-side communication device when communicating with the center-side communication device by calling from the terminal-side communication device, and transmitting the calling telephone number to the center-side communication device based on the detected telephone number Means for determining whether or not to
Based on the judgment result, the start signal to the communication device on the center side,
The center-side communication device includes means for determining whether or not the caller's telephone number is received from the center-side switching center, and means for transmitting the caller's telephone number and a ringing signal at required timing. Send data to communication equipment
And a means for selecting and transmitting either a signal requesting not to add self-identification information or a signal requesting transmission of data to which self-identification information is added when the terminal side communication device In response to the reception of either one of the request signals, the data without the self-identification information is transmitted to the center side communication device, or the data with the self-identification information is transmitted.

The above-mentioned center-side communication device supports protocols relating to various communication forms, and when receiving a calling telephone number given from the center-side switching center, the terminal based on this calling telephone number is used. It is possible to recognize the type of communication form with the side communication device and to send and receive data via a protocol in the communication form of the recognized type.

The above-mentioned center side communication device adjusts the signal level of data transmission / reception with the center side switching center according to the signal level at the time of receiving the calling telephone number given from the center side switching center. Can be

Further, when the communication with the terminal-side communication device fails, the above-mentioned center-side communication device stores the telephone number of the terminal-side communication device, and the communication with the stored partner fails more than the required number of times. When this is done, the signal level of data transmission / reception for subsequent communication with the same party can be adjusted to increase.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION The details of the present invention will be described below with reference to the embodiments shown in FIGS. 1 to 5 relate to a first embodiment of the present invention, FIG. 1 is a configuration diagram of a communication system, FIG. 2 is a configuration diagram of a center-side communication device, and FIG.
FIG. 4 is a configuration diagram of the terminal side communication device, FIG. 4 is a flowchart for explaining the operation of the center side communication device, and FIG. 5 is an explanatory diagram showing an example of a communication sequence.

In the figure, A shows the whole communication system, and the communication system A is a center side communication device 1, a terminal side communication device 2, a center side switching center 3, a terminal side switching center 4 and a telephone line. Including 5 and.

In the first embodiment, the center side communication device 1
, CCITT (International Telegraph and Telephone Commission) V. 21
FSK or PB (DTM) that conforms to the recommended signal format
F) and the like can support a protocol capable of supporting only one of the communication modes, and a single specific type (classified by the communication mode) for the center-side communication device 1
The case where the terminal side communication device 2 is connected is given as an example.

The center side communication device 1 comprises a host computer 6 and a center side line terminal device 7. The terminal side communication device 2 includes a terminal side line terminal device 8, gas, water,
It is provided with telegram meters 9A to 9C for electric power and the like and a telephone 10.

When the center-side switching center 3 communicates with the center-side communication device 1 by calling from the terminal-side communication device 2, in addition to the conventional general connection processing, the center-side communication device 1 is designated in advance. The so-called outgoing telephone number notification processing is performed, in which the outgoing telephone number of the terminal-side communication device 2 that is set, that is, the telephone number of the originating terminal-side communication device 2 is transmitted. That is, the center side switching center 3 receives the signals and data from the center side communication device 1 and the terminal side communication device 2, and the activation signal for the center side communication device 1 and the terminal side communication device 2. Off-hook state of the line terminal device 7 of the center-side communication device 1 and means for sending out a calling signal at a required timing (loop between L1 and L2)
In addition to a well-known configuration such as means for detecting an on-hook state (loop break between L1 and L2), when communication with the center-side communication device 1 is made by transmission from the terminal-side communication device 2, A means for detecting a telephone number, a means for judging whether or not to send the originating telephone number to the center side communication equipment 1 based on the detected telephone number, and a means for the center side communication equipment 1 based on the judgment result. And means for transmitting the calling telephone number.

The line terminal device 7 of the center side communication device 1 is
A call signal detection unit 701 that detects a call signal and a transmission / reception unit 702 that sends and receives a calling telephone number, a start signal, a call signal, a modem signal, and communication data between the terminal side line terminal device 8 and an internal line. 5, a line control unit 703 for connecting / disconnecting (off-hook / on-hook), a clock 704, and a memory 705 having an area for storing a received outgoing telephone number and an area for storing a telephone number of an erroneous communication partner. And a control unit (microcomputer) 706 for executing the program shown in the flowchart of FIG.
The control unit 706 is provided with an interface 707 that connects the host computer 6 and is compliant with RS232C, for example. As described in the following operation description, the control unit 706 described above has means for communicating with the host computer 6, means for judging whether or not the originating telephone number is received from the center side switching center 3, and terminal side based on the judgment result. The communication device 2 includes at least means for selecting and transmitting either one of a signal requesting data transmission without self-identification information and a signal requesting data transmission with self-identification information.

The line terminal device 8 of the terminal-side communication device 2 includes a polar reversal detection unit 801 for detecting polarity reversal, a ringing signal detection unit 802 for detecting a ringing signal, a modem unit 803 for transmitting and receiving data, and a terminal side. From a dial unit 804 that dials when making a call from a telephone, a switching unit 805 that connects and disconnects the telephone 10 to and from the telephone line 5, and a semiconductor memory that stores a calling telephone number of a specific partner to be communicated with. Code setting unit 806 and electronic meter 9A
9C to the interface 807, and a line-off-hook detection unit 808 that detects the usage state of the telephone line 5.
An off-hook detection unit 809 that detects the usage state of the telephone 10, a busy tone sending unit 810 that sends a busy tone to the telephone 10, a high-accuracy clock unit 811 as a clock, and these components are controlled. And a control unit (microcomputer) 812. This terminal-side line terminal device 8 is either data with self-identification information (ID) or data without self-identification information (ID) based on two types of data transmission request signals received from the center-side communication device 1. Has a function of selecting and transmitting.

Next, the communication sequence of the communication system A described above will be described with reference to FIG. Here, the case where communication is performed with the center-side communication device 1 by transmission from the terminal-side communication device 2 is taken as an example. Further, the following description is mainly about the operation of the center-side communication device 1.

In short, when the terminal-side switching center 4 is off-hook and the communication partner number is dialed by the call from the terminal-side communication device 2, first, between the center-side switching center 3 and the center-side communication device 1. Performs connection processing (S1 to S8), and then performs data communication processing (S9) between the terminal side communication device 2 and the center side communication device 1.

Specifically, when the line terminal device 7 of the center-side communication equipment 1 detects a start signal sent from the center-side switching center 3 which receives the dial of the terminal-side switching center 4, it goes off-hook, and this off-hook is set. The detected modem signal transmitted from the center side switching center 3 is received (S1).

It is determined whether the received modem signal includes a calling telephone number (S2). If it is determined that the call is not included in S2, the device goes on-hook, waits for a ringing signal such as a ringer sent from the center-side switching center 3 that has detected this on-hook, and when the ringing signal is received, it goes off-hook (S3). , Proceed to S5 below. However, if it is determined to include in S2, the received calling telephone number is stored in the memory 705, the ID flag is set (S4), and then the above S3 is executed.

In S5, it is determined whether or not the calling telephone number is received by the above-mentioned ID flag. When it is determined that there is no reception in S5, a signal requesting data transmission with self-identification information is transmitted to the terminal side communication device 2 (S).
6). However, if it is determined in S5 that there is a reception, it is determined whether the calling telephone number stored in S4 is previously registered (S7). This determination is made on the basis of the collation result by collating the calling telephone number stored in the host computer 6 with a plurality of telephone numbers registered in advance. If it is determined in S7 that there is no registration, the process proceeds to S6 described above and the terminal side communication device 2
A signal for requesting data transmission with self-identification information is sent to. On the other hand, when it is determined in S7 that registration is performed, a signal requesting data transmission without self-identification information is sent to the terminal communication device 2 (S8).

In this way, the center side communication device 1 and the terminal side communication device 2 are connected. As a result, the data communication process between them is performed (S9). In this data communication, the terminal-side communication device 2 sends data without self-identification information or sends self-identification information in response to two types of data transmission request signals sent from the center-side communication device 1. It will send out the attached data. An example of the communication sequence described above is shown in FIG.

According to the first embodiment described above, when the data is transmitted from the terminal side communication device 2 without attaching the self-identification information, the total amount of data in the data communication process can be greatly reduced, so that the communication time can be shortened. It will be possible to contribute to the reduction of communication costs, such as shortening.

The present invention is not limited to the above embodiment, and various applications and modifications are conceivable.

(1) FIGS. 6 and 7 show a second embodiment of the present invention. In the second embodiment, the communication device 1 on the center side is, for example, CCITT (International Telegraph and Telephone Committee) V.V. Two
FSK and PB (DTM) that comply with the signal format of 1 Recommendation
F), etc., which can support a protocol compatible with the communication form, and for the center side communication device 1,
Not limited to the situation in which a single specific type (classified by the communication mode) of the terminal communication device 2 is connected, a plurality of different types of terminal side communication devices 2A, 2B ... 2N are connected. The case is given as an example. For example, terminal side communication device 2A
Is in the FSK communication mode, and the terminal side communication device 2
B is in the PB (DTMF) communication mode, and the terminal-side communication device 2N is in the other communication mode.

The difference between the second embodiment and the first embodiment is that the center side communication device 1 grasps the type (classification by communication form) of the terminal side communication devices 2A to 2N with which the center side communication device 1 communicates (S10). ) Is added, and the data communication process (S9) can be appropriately performed according to the type ascertained.

Specifically, when proceeding from S7 to S8, S8
In the preceding stage, the type of the terminal-side communication device 2 as the communication partner is recognized based on the calling telephone number stored in the memory 705 in S4 (S10). Based on this recognition result, the data communication process in S9 is performed based on the protocol corresponding to the terminal-side communication device 2.

Thus, as the center-side communication device 1,
If it is possible to know the type of the terminal-side communication device 2 that is a communication partner by the calling telephone number sent from the center-side switching center 3, the communication between the center-side communication device 1 and the terminal-side communication device 2 Since proper data communication can be performed via the protocols corresponding to each other, it is easy to avoid failure of data communication.

(2) FIG. 8 shows a third embodiment of the present invention. The difference between the third embodiment and the first embodiment is that, in consideration of the fact that the signal attenuation characteristics from the center-side switching center 3 to the center-side communication equipment 1 vary depending on the construction conditions, what kind of terminal-side communication equipment Process for making it difficult for data communication to fail even for 2 (S12, S13)
Is added before the data communication process of S9.

Specifically, when it is determined that the modem signal received in S2 includes the calling telephone number, S4
The reception level of the originating telephone number is detected in the stage before the processing of (S12), and in the subsequent stage of S3, the transmission / reception level of data with respect to the center-side switching center 3, that is, the transmission intensity and the reception sensitivity of the data. Is adjusted based on the detection result (S13). The reference value of the transmission level can be set to -20 dBm, and the upper and lower sides of the reference value can be adjusted in four steps, that is, eight steps in total.

In short, in S12, the signal attenuation characteristic from the center-side switching center 3 to the center-side communication device 1 is grasped, and in S13, the transmission / reception level of data communication, that is, the transmission is performed according to the grasped signal attenuation characteristic. The strength and reception sensitivity are adjusted to be appropriate. By doing so, it becomes easy to avoid communication failure due to variations in signal attenuation characteristics, and it is possible to contribute to improving reliability of data communication.

In the third embodiment, the feature is added to the contents of the first embodiment, but it can be added to the contents of the second embodiment.

(3) FIG. 9 shows a fourth embodiment of the present invention. The difference between the fourth embodiment and the first and second embodiments is that after the data communication process of S9, even if the data communication should fail, a process for preventing the failure from being repeated ( S20 to S26) are added.

Specifically, before the data communication process of S9, it is determined whether or not the terminal side communication device 2 which is the current communication partner has failed in data communication in the past (S20).
Here, the error storage area of the memory 705 described below is checked. If an error has occurred, the data transmission / reception level, that is, the transmission intensity and the data reception sensitivity are adjusted (S21), but if no error has occurred, the process of S21 is omitted.

Then, in the latter stage of the data communication process of S9,
It is determined whether or not the data communication process in S9 described above has been normally completed (S22). If the process is completed normally, clear the counter that counts the number of errors (S23).
To finish. On the other hand, if it does not end normally, that is, if it fails, the counter that counts the number of errors is incremented by "+1" (S24), and the number of past failures with the terminal communication device 2 that is the current communication partner is required. It is determined whether or not the number of times is n or more (S25). Here, if the number of past failures is greater than or equal to the required number n, the memory 705 is set in S4.
The calling telephone number stored in step S23 is also stored in the error storage area of the memory 705 (S26), and the processing ends after the above-described step S23. On the other hand, if the number of failures in the past is less than the required number n, the process of S26 is omitted, and the process ends after the process of S23.

Thus, depending on the failure of the data communication,
It is easier to avoid repeated failures and to improve the reliability of data communication by grasping the communication partners who have many failures and taking measures to prevent repeated failures in data communication with such parties. I can contribute.

In the fourth embodiment, the feature is added to the contents of the first embodiment, but it can be added to the contents of the second and third embodiments.

[0047]

According to the communication system of the present invention, since it is devised so that it is possible to eliminate the fact that the self-identification information is added to the data sent from the terminal side communication device in the related art, the total communication related It is possible to reduce the amount of data of the communication as much as possible, and it is possible to reduce the communication time and the communication cost.

According to the communication system of the present invention, one center-side communication device can properly perform communication with two or more types of terminal-side communication devices. , Can contribute to the improvement of system spread.

According to the communication system of the present invention, the signal attenuation characteristics from the center-side switching station to the center-side communication equipment are grasped, and the transmission / reception level of data communication, that is, the transmission intensity and the reception sensitivity, are determined according to the grasped signal attenuation characteristics. Since it can be adjusted to be appropriate, it becomes easy to avoid communication failure due to variations in signal attenuation characteristics, which can contribute to improvement in reliability of data communication.

According to the communication system of the present invention, it is possible to recognize a communication partner who has a lot of failures according to the failure of the data communication and prevent the failure of the data communication with such a partner from being repeated. This makes it easier to avoid repetition and contributes to improving the reliability of data communication.

[Brief description of drawings]

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

FIG. 2 is a configuration diagram of a center-side communication device according to the first embodiment.

FIG. 3 is a configuration diagram of a terminal-side communication device according to the first embodiment.

FIG. 4 is a flowchart for explaining the operation of the center-side communication device according to the first embodiment.

FIG. 5 is an explanatory diagram showing an example of a communication sequence according to the first embodiment.

FIG. 6 is a configuration diagram of a communication system according to a second embodiment of the present invention.

FIG. 7 is a flowchart for explaining the operation of the center-side communication device according to the second embodiment.

FIG. 8 is a flowchart for explaining the operation of the center-side communication device according to the third embodiment of the present invention.

FIG. 9 is a flowchart for explaining the operation of the center-side communication device according to the fourth embodiment of the present invention.

FIG. 10 is an explanatory diagram showing a communication sequence of a conventional communication system.

[Explanation of symbols]

A communication system 1 Center side communication equipment 2 Terminal side communication equipment 3 Center side exchange 4 Terminal side exchange 5 telephone lines 6 Host computer 7 Center side line terminal device 8 Terminal side line terminal equipment

─────────────────────────────────────────────────── ─── Continuation of front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) H04M 1/00 H04M 1/24-1/253 H04M 1/58-1/62 H04M 1/66-1 / 82 H04M 3/42-3/58 H04M 11/00-11/10 G08C 13/00-25/04

Claims (9)

(57) [Claims] 1. A terminal side communication device and a center side communication device,
A communication system that connects through terminal-side and center-side switching stations and a telephone line, and the center-side switching station uses the center-side communication device to communicate with the center-side communication device when calling from the terminal-side communication device. The center-side communication device supports various communication protocols, and when the center-side exchange receives the calling telephone number given by the center-side switching center, It recognizes the type of communication mode with the communication device on the terminal side based on the number, and sends and receives data via the protocol of the communication mode of the recognized type. Communication, the terminal side communication device is requested to transmit data without adding self-identification information to the terminal side communication device. Stem. 2. A terminal-side communication device and a center-side communication device,
A communication system that connects through terminal-side and center-side switching stations and a telephone line, and the center-side switching station uses the center-side communication device to communicate with the center-side communication device when calling from the terminal-side communication device. To the center-side communication device or to send a start signal to the center-side communication device without transmitting the call-out phone number to the center-side communication device. It supports protocols related to various communications, and when it receives a calling telephone number given from the center-side switching center, it recognizes and recognizes the type of communication mode with the terminal-side communication device based on this calling telephone number. In addition to sending and receiving data via the protocol of the communication type of the above, when the calling telephone number is given from the center side exchange, , While sending a signal requesting data transmission without adding self-identification information from the terminal side communication device, when the center side switching center gives a start signal instead of a calling telephone number to the terminal side communication device A communication system for transmitting a signal for requesting data transmission, to which self-identification information is added, from the terminal-side communication device. 3. A terminal-side communication device and a center-side communication device,
A communication system that connects via terminal-side and center-side switching stations and a telephone line, wherein the center-side switching center communicates with the center-side communication device when transmitting from the terminal-side communication device. A means for detecting the telephone number of the device, a means for judging whether or not to send the outgoing telephone number to the center side communication equipment based on the detected telephone number, and a means for the center side communication equipment based on the judgment result The center side communication device includes a start signal, the calling telephone number, and means for sending a calling signal at a predetermined timing, and the center side communication device supports various communication protocols and is provided by the center side exchange. When the number is received, it recognizes the type of communication mode with the terminal-side communication device based on this calling telephone number, and through the protocol in the communication mode of the recognized type. In addition to sending and receiving data, a means to determine whether or not the originating telephone number is received from the center-side switching center and a data transfer without adding self-identification information to the terminal-side communication device based on the determination result And a signal for requesting transmission of data to which self-identification information is added, and transmitting the selected signal. 4. A terminal-side communication device and a center-side communication device,
A communication system that connects through terminal-side and center-side switching stations and a telephone line, and the center-side switching station uses the center-side communication device to communicate with the center-side communication device when calling from the terminal-side communication device. When the center side communication device receives the caller's telephone number from the center side switching center, the center side communication device will identify itself when transmitting data to the terminal side communication device. A feature is that a signal requesting not to add information is transmitted, and the terminal-side communication device transmits data without adding self-identification information to the center-side communication device in response to reception of the request signal. Communications system. 5. A terminal-side communication device and a center-side communication device,
A communication system that connects through terminal-side and center-side switching stations and a telephone line, and the center-side switching station uses the center-side communication device to communicate with the center-side communication device when calling from the terminal-side communication device. To the center-side communication device or to send the activation signal to the center-side communication device without transmitting the caller-phone number to the center-side communication device. When the originating telephone number is received from the local exchange, the terminal-side communication device sends a signal requesting not to add self-identification information when transmitting data, and the terminal-side communication device In response to the reception of the request signal, the center-side communication device transmits data without adding self-identification information, while the center-side communication device, when receiving the activation signal from the center-side switching center, communicates with the terminal-side communication device. To the device, the terminal-side communication device sends out a signal requesting the transmission of data to which self-identification information is added, and the terminal-side communication device responds to the reception of the request signal to the center-side communication device. A communication system for transmitting data to which self-identification information is added. 6. A terminal-side communication device and a center-side communication device,
A system for connecting via terminal-side and center-side exchanges and a telephone line, wherein the center-side exchange is used to communicate with the center-side communication device when transmitting from the terminal-side communication device. Means for detecting the telephone number of the device, a means for determining whether or not to send the originating telephone number to the center-side communication device based on the detected telephone number, and a start-up for the center-side communication device based on the determination result. A signal, the calling telephone number, and a means for transmitting a calling signal at a required timing. The center-side communication device determines whether or not the calling telephone number is received from the center-side switching center, and based on the determination result. Select and send either a signal requesting not to add self-identification information or a signal requesting transmission of data with self-identification information when sending data to the terminal communication device. The terminal-side communication device transmits data without self-identification information or data with self-identification information to the center-side communication device in response to receiving one of the request signals. A communication system comprising: 7. The center side communication device supports protocols relating to various communication forms, and when receiving a calling telephone number given from a center side switching center, the terminal side based on this calling telephone number. The communication system according to any one of claims 4 to 6, which recognizes a type of communication form with a communication device and transmits / receives data via a protocol in the recognized type of communication form. 8. The sensor-side communication device adjusts the signal level of data transmission / reception to / from the center-side switching center according to the signal level at the time of receiving a calling telephone number given from the center-side switching center. A communication system according to any one of claims 1 to 7. 9. The center-side communication device stores the telephone number of the terminal-side communication device when the communication with the terminal-side communication device fails, and the communication with the stored partner fails further a required number of times or more. 9. The communication system according to claim 1, wherein the communication level is adjusted so as to increase the signal level of data transmission / reception in the subsequent communication with the other party.