JPH08228384A - Telephone equipment - Google Patents

Abstract

PURPOSE: To secure the opportunity of connection to a slave machine terminal of the destination and to reduce the charge for call as much as possible in the case of speech between slave machine terminals having a common master machine. CONSTITUTION: A table 14 of correspondence between slave machine numbers and public line numbers of slave machines is provided; and when the public line number of a slave machine terminal is inputted to an operation part 10, a control part 12 retrieves whether the slave machine terminal corresponding to this public line number exists or not. When it exists, a mode switching part 18 is switched to the transceiver mode to call it in this mode requiring no charge. If it cannot be called in the transceiver mode, the mode switching part 18 is switched to another mode, for example, the public mode to call it again. If the line is disconnected by extension of the distance between slave machine terminals in the middle of speech in the transceiver mode, the slave machine terminal is called again in the mode other than the transceiver mode.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a portable telephone device, and more particularly to a portable telephone device used in a PHS communication system.

[0002]

2. Description of the Related Art Recently, a PHS (Personal Handy Phone System) is being developed as a second-generation cordless telephone, and this PHS is a digital communication system that allows a cordless terminal for home use to be used outdoors. According to this PHS, although high-speed mobile communication is not possible, the call charge is low, the base station is small and inexpensive, the terminal is also small, and the base station is installed in an underground mall, etc. Many effects are expected, such as being able to make a call even in an area where it is not possible to make a call using the mobile phone.

A portable terminal (hereinafter referred to as a slave terminal) used for PHS is provided with various transmission / reception modes. For example, there are provided a home (self-employed) mode for normal home use, and a transceiver mode in which direct communication is performed between a plurality of terminals as a base unit of a portable terminal. That is, in the home mode, the slave terminal functions as a slave. Further, it is possible to provide a public mode in which a call is made via a public line network as in a normal mobile phone. That is, according to the PHS standard,
Self-employed (home and business) slave terminals can also be registered as public terminals.

Here, when making a call between the child terminals of a certain parent machine, the following four methods can be considered.
That is, in the transceiver mode, call the other party's child terminal directly to make a call, in the public mode call the other party's child terminal via the public line, and in the home mode connect to the parent machine There is a method of calling the other party's handset terminal through the public line via the machine to make a call, and a method of connecting to the parent machine in the home mode and calling the other party's handset terminal via the master machine.

Therefore, when the operator has the slave terminal and the master calls the same slave terminal, the operator calls the slave terminal in the home mode or the transceiver mode according to the slave terminal number of the partner slave terminal and the operator owns the slave terminal. If the handset terminal is a self-employed / public handset, it can be called by a public telephone number.

Here, the case of using the public mode will be described in detail. Since the slave terminals function as ordinary mobile phones outdoors, it is possible to assign a telephone number as a mobile phone to each slave terminal. is there. This telephone number is different from the telephone number of the parent machine when the child machine terminal is the child machine. Therefore, as a method for making a call between the slave terminals, it is possible to make a call through a public line by dialing the telephone number of the partner slave terminal as a mobile phone. On the other hand, conventionally, there has been proposed a telephone device which automatically selects the cheapest one from the available telephone service companies when making a call to the other party.

[0007]

However, when a call is made by a certain calling method and an incoming call is not received by that method, it may be unclear to the operator of the slave terminal whether or not there is another calling method. . Then, although there is another calling method, there is a problem in that the calling is not performed by the other calling method, the other calling method is wasted, and the connection opportunity with the partner terminal is reduced. is there. Further, even if the operator knows that there is another calling method, if the call cannot be received by a certain method, the calling operation by another calling method must be performed again, which is troublesome.

Further, when a child terminal having a common parent terminal is taken out to the outside and one child terminal tries to call the other child terminal through a public line, Even if the remote terminal is located close enough to be called in the transceiver mode, the call is made via the public line, and there is a problem that telephone charges are incurred.

[0009] Therefore, when a call is made between the slave terminals having the same master, if the call cannot be made by a certain calling method, the presence / absence of another calling method is notified to the other terminal of the other party. It is an object of the present invention to provide a portable terminal that can secure a connection opportunity and can reduce telephone charges as much as possible.

[0010]

The present invention was made to solve the above-mentioned problems. First, a telephone device is provided with call identification data indicating another telephone device. If you called, but the other telephone device does not receive the call,
It is characterized in that a call is made again with other call identification data for calling the other telephone device. Secondly, the other telephone device is a PHS slave device, the calling identification data is a slave device number of the PHS slave device, and the other identification data is a public line number of the PHS slave device. It is characterized by being.

Thirdly, the other telephone device is PH
S-slave unit, the call identification data is the public line number of this PHS slave unit, and the other identification data is this PH
It is a slave unit number of the S slave unit. Also, the fourth
Is, if the line is disconnected during a call in one mode,
A feature is that a call is made again in another mode.

Fifthly, the first storage means (14a) for storing the call identification data of the other handset terminals.
And second storage means (14) for storing the presence / absence of a public telephone number of the other slave terminal corresponding to the call identification data.
b) and are included. And sixth,
First storage means (14a) for storing the call identification data of the other handset terminal, and second storage means (14b) for storing the public telephone number of the other handset terminal corresponding to the call identification data. And are included.

Seventh, the storage means (14) for holding the public telephone numbers of other slave terminals and whether or not there is a corresponding slave terminal when the public telephone number is input. Search means (12) for searching by the storage means and switching means (18) for switching the transmission mode to the transceiver mode when the search means determines that there is a corresponding slave terminal. Eighth, the seventh
In the above configuration, after a call is made in the transceiver mode, an incoming call detection means (20) for detecting whether or not an incoming call has been made, and if it is determined that the incoming call has not been made, the reoccurrence occurs in a mode other than the transceiver mode. Recall means (16,
18) is preferably provided.

Ninth, the storage means (14) for holding the slave number and the public telephone number of another slave terminal and the public telephone number corresponding to the public telephone number when the public telephone number is input. A search means (12) for searching the storage means for the presence or absence of a slave terminal, and when the search means determines that there is a corresponding slave terminal, the transmission mode is called by a public telephone number. Switching means (18) for switching to another mode that is cheaper than the case is provided.

Further, tenthly, in addition to the seventh construction, switching is performed when a call is made in the transmission mode set by the switching means (18) and the other handset terminal does not receive the call. The means (18) switches to a transmission mode in which the public telephone number can be called, and the re-calling is performed using the public telephone number.

Eleventhly, a line disconnection detecting means (20) for detecting disconnection of a line during a call with another slave terminal in a transceiver mode and a line disconnection when it is judged that the line is disconnected. Recalling means (16, 18) for recalling in a mode other than the transceiver mode. Further, twelfthly, when a calling operation is performed in the transceiver mode instead of a public telephone number input operation to make a call in the transceiver mode and the receiving side does not receive the call, a mode other than the transceiver mode is used. It is characterized by making a recall call.

[0017]

In the telephone device of the first configuration of the present invention, a call is made with the call identification data indicating another telephone device, but when the other telephone device does not receive the call, the other telephone device is called. Since the call is made again by using the call identification data, the line connection with the receiving side can be facilitated. Further, in the above-mentioned second configuration, although the call is made with the PHS slave unit number, the call is made again with the public line number when the call is not received, so the line connection opportunities with other telephone devices increase.

Similarly, in the third configuration, the PH
Although the call is made using the public line number of the S handset but is not received, the call is made again using the handset number of the PHS handset, so that it is possible to increase line connection opportunities with other telephone devices. Further, in the telephone device of the above-mentioned fourth configuration, when a line is connected during a call in a certain mode, the call is reissued in another mode, so that the call can be resumed immediately even during the call.

Further, in the telephone device of the fifth configuration, the call identification data of the other handset terminal is stored in the first storage means (14a), and the other handset terminal is stored in the second storage means (14b). Since the presence / absence of the public telephone number is stored, when the call is not made via the public telephone number and the call is not received, the call identification data of the handset terminal and the presence / absence of the corresponding public telephone number are searched. As a result, it is possible to inform whether or not the call using the public telephone number is possible.

Further, in the telephone device of the sixth configuration, the call identification data of the other handset terminal is stored in the first storage means (14a), and the other handset terminal is stored in the second storage means (14b). Since the public telephone number of the mobile phone is stored, it is possible to make a call by using the public telephone number by notifying the public telephone number of the slave terminal when a call is made without going through the public telephone number and the call is not received. You can

In addition, in the telephone device of the seventh structure, when the public telephone number is input, the searching means (1
2) searches the storage means (14) for the presence of a slave terminal corresponding to the public telephone number. If there is a corresponding slave terminal, the switching means (18) switches the transmission mode to the transceiver mode and calls. In the telephone device of the present invention, when a call is made to another slave terminal, even if a public telephone number is input, the call is first made in the transceiver mode, so that the telephone charge can be reduced.

In addition, in the telephone device of the eighth structure, the incoming call detecting means (20) detects whether or not the call is made in the transceiver mode and the call is received at the other terminal. When the incoming call detection means (20) determines that the incoming call has not been made, the recalling means (16, 18) makes a recalling call in a mode other than the transceiver mode. In the telephone device of the present invention, when the connection cannot be made in the transceiver mode, the call is made again in another mode, so that it is possible to increase the line connection opportunities with the receiving side.

Further, in the telephone device of the ninth structure, when the public telephone number is input, the searching means (1
2) searches the storage means (14) for the presence of a slave terminal corresponding to the public telephone number. When there is a corresponding slave terminal, the switching means (18) switches to another mode which is cheaper than the case of making a call using a public telephone number and calls. Therefore, even if the public telephone number is input, the call is first made in the cheaper transmission mode, so that the telephone charge can be reduced.

Further, in the telephone device of the tenth structure, a call is made in a cheaper transmission mode, and when a call is not received by another slave terminal, the public telephone number is set to a transmission mode in which a call can be made. Since the call is switched and the call is recalled, it is possible to increase the line connection opportunity with the receiving side.

In the eleventh configuration of the telephone device, when the line is disconnected during a call in the transceiver mode, the line disconnection detecting means (20) detects disconnection of the line. When the disconnection of the line is detected, the recalling means (16, 18) makes a call again in a mode other than the transceiver mode. Therefore, it is possible to call again immediately during the call. Further, in the telephone device having the twelfth structure, not only in the calling operation using the public telephone number but also in the calling operation in the transceiver mode, if the call is not received in the transceiver mode, the call is reoccurred in a mode other than the transceiver mode. To call. As a result, it is possible to omit the input operation of the public telephone number and immediately call again.

[0026]

Embodiments of the present invention will be described with reference to the drawings.
A mobile terminal A as a portable telephone device based on the present invention is
1, the operation unit 10, the control unit 12, the slave unit number-public line number table (hereinafter referred to as "table") 14 as a storage unit, and the dial as a calling unit. It has a unit 16, a mode switching unit 18 as a switching unit, a detection unit 20 as an incoming call detection unit and a line disconnection detection unit, and a radio unit 22. This child device terminal A also functions as a child device of a parent device in the home, and it is assumed that there are other child device terminals for the parent device.

Here, the operation section 10 is composed of operation switches and operation buttons for performing various operations in the slave terminal A, and dial operation is also performed by the operation section 10. The operation unit 10 is also provided with a display unit.
The control unit 12 controls the operation of each of the above units. The control unit 12 also functions as a search means.

The table 14 includes a slave unit number storage section 14a for storing slave unit numbers of other slave terminals as call identifying data, and a public line number as other call identifying data corresponding to the slave unit number. And a public line number storage unit 14b for storing As for the slave terminal to which the public telephone number is not assigned, as shown in the slave 3 of the table 14 in FIG. 1, the public line number is not stored as a matter of course.

The dial section 16 is for dialing a telephone number or the like designated by the operation section 10, and generates, for example, a predetermined frequency signal corresponding to the telephone number. In addition, the mode switching unit 18 includes the control unit 1
The transmission / reception mode is switched to various modes in accordance with the instruction of 2, and switching is performed between various modes such as a home mode, a public mode, and a transceiver mode. Further, the detection unit 20 performs various detections by various signals sent from the outside, and specifically detects whether the other party has received a call, whether the line is connected, or the like. . The wireless unit 22 is in charge of wireless communication with the base station, the base unit, and other terminals, and modulates call data and the like by a modulation method that conforms to the PHS communication method, or vice versa. It demodulates data.

The usage state of the slave terminal A in the above configuration will be described. It is assumed that this child device terminal A is taken out by the operator A, and further another child device terminal B that shares the parent device with this child device terminal A is also taken out by the operator B. It is assumed that the slave terminal B has the same configuration as the slave terminal A. Here, it is assumed that the operator A uses the cordless handset terminal A and attempts to call the cordless handset terminal B owned by the operator B. Here, the operation unit 1 of the child device terminal A
It is assumed that the public line number of the slave terminal B is input to 0 to call the slave terminal B. That is, this is the case where the operator A uses the public line to call the child device terminal B.

Then, the control unit 12 searches the table 14 to determine whether or not the input public line number is the public line number of another slave terminal. Here, when the input public line number is searched, that is, when the input public line number is the public line number of another slave terminal, the corresponding slave unit number is searched. Then, the control unit 12 switches the mode switching unit 18 to the transceiver mode, sends the calling party's cordless handset number to the dial unit 16, and then causes the radio unit 22 to call the cordless handset terminal B in the transceiver mode. That is, a call is made. In this case, the display of the operation unit 10 displays that the call is being made in the transceiver mode.

In response to a call from the handset terminal A, when the handset terminal B receives an answer and makes an answer back, the detecting section 20 detects the answer back, and the call is directly made in the transceiver mode. .

On the other hand, in response to a call from the slave terminal A,
When there is no answer back from the handset device B, the detection unit 20 detects this and notifies the control unit 12.
Here, as a case where there is no answer back, it is considered that the distance between the slave terminal A and the slave terminal B is long, or the slave terminal B side is not switched to the transceiver mode.

Then, the slave terminal A switches from the transceiver mode to another mode and calls using the public line. Specifically, the control unit 12 switches the mode switching unit 18 to the public mode, sends the previously input public line number to the dial unit 16, and calls the slave terminal B by the public line. In this case, the display unit of the operation unit 10 displays the public mode. Here, as a route for calling by a public line, there are a case of calling through a base station and a case of calling through a home base unit.

Here, as a method of calling using a public line, in addition to the public mode, when there is a child terminal A in the home, the home mode can be used.
If it can be detected that the child device A is in the home,
The call may be made not only in the public mode but also in the home mode.
When the operator who has learned that the line cannot be connected in the transceiver mode switches the mode to another mode, the call may be made again in the other mode. Further, in the above description, when the public telephone number input by the operator is the public telephone number of another child terminal, the call is made in the transceiver mode, but when the call in the home mode is possible, Since there is no telephone charge in the home mode, the call may be made in the home mode.

In the above example, when there is no answer back from the slave terminal B, the mode is switched to the public mode. However, the following mode is notified and then another mode is set. You may call at. That is, the slave terminal A notifies the operator of the presence / absence of another calling method. That is, the control unit 12
Confirms whether the public telephone number of the slave terminal B is stored by searching the table 14 or the like, and if stored, displays the presence or absence of another calling method on a display unit (not shown). Or, let me know by voice. As an example of the display, it may be possible to display "Do you call again using another method" on the display unit. Then, after confirming the recalling call to the operator, the recalling call is performed in the public mode. Note that the contents of another calling method may be notified instead of notifying the presence or absence of another calling method. That is, the public telephone number of the partner terminal device may be displayed or notified by voice.

Next, the operation when a call is being made in the transceiver mode as described above will be described. Here, the communication range in transceiver mode is 10
Since the distance is about 0 m to 200 m, when the distance between the slave terminal A and the slave terminal B becomes long, the line may be disconnected during the call. In that case, the detection unit 20 detects that the line has been disconnected by checking that the carrier level has decreased, and transmits it to the control unit 12.

Here, as a method of checking that the line has been disconnected, a method of checking that the carrier level has dropped is adopted, but the following method is also conceivable. That is, a method is conceivable in which a predetermined signal is sent during a call and a line is disconnected when the signal cannot be detected. Then, the control unit 12 confirms whether or not the call is made again on the public line as described above, and then the mode switching unit 18
To the public mode to call the slave terminal B on the public line.

Here, at the time of re-calling through the public line, the control unit 12 sends the information of the public line number to the dial unit 16, but the control unit 12 holds the first input public line number. You can
Alternatively, the information of the public line numbers of the slave terminals A and B may be exchanged during communication between the slave terminals A and B in the transceiver mode.

On the other hand, in the handset terminal B, when the disconnection of the line in the transceiver mode is detected, the control unit 12 sets the mode switching unit 18 to the public mode so that the call from the public line can be answered. To do. Note that the operator of the handset device B may manually switch to the public mode instead of switching automatically as described above. Also, the child device B on the receiving side
When the receiver is configured to be able to receive in any mode, it is not necessary to switch the mode. Recalling after the line is disconnected does not have to be performed from the slave terminal A, and may be performed from the slave terminal B.

As described above, in the handset terminal A of the present embodiment, even when the public line number is input, the call is made in the transceiver mode. Therefore, the opportunity for a call in the transceiver mode is increased and the telephone charge is saved. You can
In addition, even if you cannot call in the transceiver mode, you will be notified of the existence of other calling methods, etc., and you will be able to call again using another method, for example, using the public line, so you can be sure that you can talk to the other party. Is possible. Also,
Even if the line is disconnected during a call in the transceiver mode, the call is made again using the public line, so that the call can be re-established immediately even during the call.

Next, the second embodiment will be described. Second
The portable telephone device in the embodiment is substantially the same as that in the first embodiment, but not only when the public line number of the slave terminal is input when calling another slave terminal, Even when the cordless handset number is input, the call is first made in the transceiver mode first. When the call is not received in the transceiver mode, the pause state is temporarily displayed, and after the display of the operation unit 10 displays whether or not the call is made over the public line, the operator calls the public line again. Recall on the line.

That is, even if the operator tries to call in the transceiver mode by inputting the cordless handset number, if he / she does not connect, in order to make sure that the call can be made, the operator tries to call again in another mode. To do. Further, according to the present embodiment, the input operation of the public line number can be omitted. However, in this case, the operator
There are cases where you are trying to call in the transceiver mode because there is no telephone charge, so even if the other party cannot receive the call in the transceiver mode, you will not immediately call in another mode, and the operator will not be able to call. Check whether it is okay to call and then call again.

Next, a third embodiment will be described. Third
The portable telephone device in the embodiment is substantially the same as that in the first embodiment, but when the operator inputs the public telephone number, first, the public telephone number is used as the call identification data to make the public telephone line. Make a call by. Here, as a case of making a call using a public telephone number, there are a case of making a call in a public mode and a case of making a call in a home mode through a public line via a master unit. When the call is received via the public line, the call is continued as it is. On the other hand, if the public telephone number is called and the call is not received, the detection unit 2
0 detects this and sends it to the control part 12.

Then, the control unit 12 displays the table 1
4 is searched for whether or not there is another cordless handset number as other call identification data corresponding to the entered public telephone number. Then, when there is a corresponding slave unit number, the control unit 12 switches the mode switching unit 18 to the transceiver mode and calls again.

It should be noted that the transceiver may be called after the notification of another calling method is given as follows. That is, if the call cannot be made by using the public telephone number, the presence or absence of another calling method such as the transceiver mode is displayed or notified by voice. As an example of the display, it may be possible to display "Do you call again using another method" on the display unit. Then, after confirming the recalling call to the operator, the recalling call is performed in the public mode.

Regarding the presence / absence of another calling method, if the public line number corresponding to the handset number is stored in the table 14, it is judged that another method exists.
If the public line number is not stored, it is determined that there is no other method. Note that the contents of another calling method may be notified instead of notifying the presence or absence of another calling method. That is, the cordless handset number of the partner cordless handset terminal is displayed or notified by voice. Further, when the call is made using the public telephone number and the call is not received, the call is made again in the transceiver mode. However, the call may be made in the home mode via the master unit.

As described above, according to the portable telephone device of the third embodiment, the operator makes a call via the public line,
If the call is not connected, the call is made by another method, so that it is possible to secure more line connection opportunities with the partner side terminal.

[0049]

According to the telephone device according to the first to third aspects of the present invention, in the case where the call identification data indicating another telephone device is called and the other telephone device is not called. Since another call identification data for calling another telephone device is used to make a call again, the line connection to the receiving side can be facilitated.

Further, in the telephone device according to the fourth aspect, when a line is connected during a call in a certain mode, the call is re-established in another mode. Therefore, the call can be restarted immediately even during the call. You can Further, in the telephone device according to the fifth aspect, it is possible to inform whether or not the call by the public telephone number is possible when the call is made without the public telephone number and the call is not received. Further, in the telephone device according to claim 6, when the call is not made through the public telephone number and the call is not received, the public telephone number of the handset terminal is notified to allow the call by the public telephone number. Can be

Further, in the telephone device according to the seventh aspect, when a call is made to another slave terminal, even if a public telephone number is input, the call is first made in a transceiver mode in which no telephone charge is applied. Since it does, the telephone charge can be reduced. Further, in the telephone device according to the eighth aspect, when the telephone device cannot be connected in the transceiver mode, the telephone device is recalled in another mode, so that it is possible to increase the line connection opportunity with the receiving side.

Further, in the telephone device according to the ninth aspect, even if the public telephone number is input, the call is first made in the cheaper transmission mode, so that the telephone charge can be reduced. Further, in the telephone device according to claim 10, a call is made in a cheaper transmission mode, and when a call is not received by another slave terminal, the public telephone number is switched to a transmission mode in which a call can be made. Since the call is recalled, it is possible to increase the line connection opportunity with the receiving side.

Further, in the telephone device according to the eleventh aspect, even if the line is disconnected during the call in the transceiver mode, the call is made again in another mode, so that the call can be made again immediately during the call. Further, in the telephone device according to the twelfth aspect, not only when a public telephone number is input to make a call but also when a call operation is performed in the transceiver mode, if the call is not received in the transceiver mode, the telephone device is not in the transceiver mode again. Since the call is reissued in this mode, it is possible to omit the input operation of the public telephone number and immediately call again.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a terminal in an embodiment according to the present invention.

FIG. 2 is an explanatory diagram showing a usage state of a terminal in the embodiment according to the present invention.

[Explanation of symbols]

 A, B Handset terminal 10 Operation unit 12 Control unit 14 Table 16 Dial unit 18 Mode switching unit 20 Detection unit 22 Wireless unit

Claims (12)

[Claims] 1. A telephone device, wherein other call identification data for calling the other telephone device when a call is made with the call identification data indicating the other telephone device but the other telephone device does not receive the call. A telephone device characterized by making a call again with. 2. The other telephone device is a PHS slave device,
2. The telephone device according to claim 1, wherein the calling identification data is a handset unit number of the PHS handset, and the other identification data is a public line number of the PHS handset. 3. The other telephone device is a PHS slave device,
2. The telephone device according to claim 1, wherein the calling identification data is a public line number of the PHS handset, and the other identification data is a handset number of the PHS handset. 4. A telephone device having a plurality of transmission modes, wherein the line is disconnected during a call in a certain mode,
A telephone device characterized by making a call again in another mode. 5. A telephone device as a child device terminal for a parent device, and first storage means (14a) for storing call identification data of another child device terminal that can be called from the telephone device, Second storage means (14b) for storing the presence / absence of a public telephone number of the other slave terminal corresponding to the identification data.
And a telephone device. 6. A telephone device as a child device terminal for a parent device, comprising: first storage means (14a) for storing call identification data of another child device terminal that can be called from the telephone device; A second storage means (14b) corresponding to identification data and storing a public telephone number of the other slave terminal, the telephone device. 7. A storage device (1) having a plurality of transmission modes, which is a telephone device as a child device terminal for a certain parent device, and holds public telephone numbers of other child device terminals.
4), and when a public telephone number is input, a search means (12) for searching the storage means for the presence or absence of a slave terminal corresponding to the public telephone number, and a corresponding child by the search means. A telephone device comprising: switching means (18) for switching a transmission mode to a transceiver mode when it is determined that there is a mobile terminal. 8. An incoming call detecting means (20) for detecting whether or not an incoming call has been made at a partner terminal after the telephone device has made an outgoing call in a transceiver mode.
And a re-calling means (16, 18) for re-calling in a mode other than the transceiver mode when the call-in detection means determines that the call has not been received. 7. The telephone device according to 7. 9. A storage device (14) having a plurality of transmission modes, which is a telephone device as a child device terminal for a certain parent device, and holds a child device number and a public telephone number of another child device terminal. And, when a public telephone number is input, a search means (12) for searching the storage means for the presence or absence of a slave terminal corresponding to the public telephone number, and a slave terminal corresponding to the search means. If it is determined that the transmission mode is present, the switching means (1) for switching the transmission mode to another mode that is cheaper than the case of making a call using a public telephone number
8) and a telephone device comprising: 10. The telephone device further makes a call in a transmission mode set by the switching means (18),
10. The switching means (18) switches to a transmission mode in which the public telephone number can be called when a call is not received at the other slave terminal, and the re-calling is performed using the public telephone number. The telephone device described in. 11. A telephone device having a plurality of transmission modes and serving as a child device terminal for a certain parent device, and a line for detecting disconnection of the line during a call with another child device terminal in transceiver mode. Disconnection detection means (20)
And a re-calling means (16, 18) for re-calling in a mode other than the transceiver mode when the line disconnecting means determines that the line is disconnected. 12. The telephone device further performs a re-call in a mode other than the transceiver mode even when a call operation in the transceiver mode is performed and the call is not received even if the call is made in the transceiver mode. The telephone device according to claim 8.