JP2002252678A - Portable terminal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a portable terminal that enables internet phone-calling by itself. SOLUTION: The portable terminal 10 is able to convert voice into voice data based on a voice coding form 1 of a mobile communication network 1 and additionally a voice coding form 0 which enables transmission over a internet 4. When voice data converted into the voice coding form 0 is sent to the internet 4 via the mobile communication network 1, a gateway 7 converts the voice data into analogue voice, then transmitting the converted voice to a telephone device 3b through a analogue communication network 3, and thereby the internet phone-calling between the portable terminal 10 and the telephone device 3b are performed. Therefore, the portable terminal 10 makes the internet phone-calling possible by itself, and consequently enables the fee for telephone call to be kept cheep, for example even if it is a expensive call for overseas, while keeping superiority of excellent portability.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a portable terminal device having an Internet calling function.

[0002]

2. Description of the Related Art Conventionally, when a mobile communication network to which a mobile phone belongs has an Internet connection, for example, a gateway, the mobile communication network has a mobile phone that can access the gateway or a service that can access the gateway. The receiving mobile phone can connect to the Internet with the mobile phone alone. In a car navigation system using a mobile phone only as a communication means, an Internet connection is possible via the mobile phone.

[0003]

However, in the conventional portable telephone, the Internet communication is not realized by the portable telephone alone. The Internet call here refers to making a call through a network that is communicated by IP (Internet Protocol). For example, a call charge when calling another portable telephone using a conventional portable telephone may be set higher than a call charge between general telephones connected to a public line network. Furthermore, when making a call overseas from a mobile phone, the call charge is particularly set high.

[0004] Therefore, a user of a mobile phone cannot easily call a foreign country using a mobile phone due to a high call charge. In such a conventional system,
Call rates could not be kept low.

[0005] In general, in an Internet call using a PC or the like, a telephone call is made by converting voice into data or vice versa. However, even if an attempt is made to make an Internet call using a mobile phone, as shown in FIG. 9, a unique voice coding system for the mobile communication network to which the mobile phone is connected is set. In addition, Internet calls can be made only between mobile phones using the same voice coding method. FIG. 9 is a list of speech coding schemes corresponding to a mobile communication network.

The present invention has been made in view of such a situation, and an object of the present invention is to provide a portable terminal device capable of making an Internet call by itself.

[0007]

A portable terminal device according to the present invention for achieving the above object is a portable terminal device connectable to the Internet from a mobile communication network. And a function of converting the voice data of the voice coding system transmitted from the Internet into voice.

According to this portable terminal device, when the portable terminal device can be connected to the Internet, the speech encoding unit converts the speech into speech data transmitted on the Internet, and the speech data transmitted from the Internet. Is converted into voice, so that Internet communication can be performed with the portable terminal device alone. In addition, since Internet calls can be made by itself, it is possible to reduce the cost of calls, for example, even for calls to overseas where the cost of calls is high, while maintaining the advantage of excellent portability.

[0009] In the portable terminal device according to the present invention, the speech encoding unit performs conversion for a plurality of different speech encoding schemes.

According to the portable terminal device, for example, when the portable terminal devices connected to the mobile communication networks having various voice coding systems communicate with each other via the Internet, the Internet call cannot be conventionally performed. In the present invention,
Since conversion corresponding to a plurality of voice coding methods can be performed by the voice coding unit, Internet communication is possible.

[0011] In the portable terminal device according to the present invention, the speech encoding unit has a speech encoding method commonly used in a communication network different from the mobile communication network of the portable terminal device.

According to this portable terminal device, since it has a common speech coding system with different communication networks, it is possible to make Internet calls even with different communication networks.

The portable terminal device according to the present invention is characterized in that the portable terminal device has only the audio coding method for the audio data transmitted on the Internet.

According to the portable terminal device, since only the speech encoding method for the speech data exchanged on the Internet is supported, the configuration as the portable terminal device is simplified, and the manufacturing cost of the portable terminal device is reduced. It is possible to provide a portable terminal device dedicated to Internet calls that can be made.

[0015] The portable terminal device according to the present invention is characterized in that the portable terminal device is provided with a selection unit for selecting an Internet call made via the Internet and a call in the mobile communication network.

According to this portable terminal device, the user of the portable terminal device can easily select an Internet call or a normal call in the mobile communication network by making a selection using the selection unit.

The data conversion apparatus of the present invention is a data conversion apparatus connectable to the Internet, and converts voice data converted based on a voice coding scheme specific to a communication network into voice data corresponding to a different voice coding scheme. And a function of re-converting the voice data converted based on the different voice coding scheme into the voice data corresponding to the voice coding scheme unique to the communication network. I do.

According to this data converter, the voice data converted by the voice coding system specific to the communication network is converted into voice data corresponding to a different voice coding system, and the reverse voice data conversion function is also provided. Therefore, if the data conversion device is provided in a communication network or a gateway, even if the conventional terminal device is used as it is, it can be connected to a terminal device of a communication network of a different voice encoding system from the communication network via the Internet. Internet calls can be made.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a portable terminal device and a telephone communication system using the portable terminal device will be described below. As shown in FIG. For the sake of convenience, it is assumed that the mobile terminal device and the voice coding scheme on the Internet in each embodiment are as follows.

1) The audio encoding method supported by the gateway for Internet connection is the audio encoding method 0
And This audio encoding system 0 is an encoding system for converting audio, which is analog data, to digital data-type 0 audio data, and conversely, converting digital data-type 0 audio data to analog data, audio. It is. The Internet is an IP (Internet
Protocol) for transmitting data.

2) The voice coding method supported by the mobile communication network 1 is referred to as a voice coding method 1. The audio encoding method 1 is an audio encoding method for converting audio into digital data-type 1 audio data, and conversely, converting digital data-type 1 audio data into audio. 3) The voice coding method supported by the mobile communication network 2 is referred to as a voice coding method 2. The audio encoding method 2 is an audio encoding method for converting audio into digital data-type 2 audio data, and conversely, converting digital data-type 2 audio data into audio.

Next, the basic configuration of the portable terminal device 10 according to the present invention will be described with reference to FIG. FIG. 1 is a block diagram showing a configuration of the portable terminal device. Although the mobile terminal device 10 is a mobile terminal device that can be used in the mobile communication network 1, the mobile terminal device 20 having the same configuration is used in the mobile communication network 2.

The portable terminal device 10 includes an antenna 11 for transmitting and receiving signals to and from a base station or the like of the mobile communication network 1 of the portable terminal device 10, , The phone number of the person you are calling,
A display unit 13 for performing display and the like for operating the mobile terminal device 10
A voice input / output unit 14 for outputting a voice of a call partner or for inputting a voice or the like of a user of the mobile terminal device 10;
An operation unit 15 including, for example, numeric keys for operating the mobile terminal device 10, and a control unit 16 connected to each unit and controlling each unit are provided.

The control unit 16 corresponds to a voice coding method determined for each mobile communication network in each embodiment described later, and supports other voice coding methods. Is converted into audio data based on the audio coding scheme, and the audio data is controlled to be transmitted from the transmission / reception unit 12 and the antenna 11. In addition, audio data transmitted from a mobile communication network, the Internet, or the like is received by the antenna 11 and the transmission / reception unit 12, and the received audio data is converted into audio based on an audio encoding scheme, and is converted into an audio input / output unit 14. Control to output from. The mobile terminal device 10 performs various operations by the control unit 16.

Hereinafter, the portable terminal device and the call system in each embodiment will be described in detail with reference to the corresponding drawings.

[First Embodiment] FIG. 2 is a system configuration diagram showing a configuration of a communication system according to this embodiment. This communication system includes a mobile communication network 1 having a circuit switching network 1a and a packet network 1b, a circuit switching network 2a and a packet network 2b.
, A mobile communication network 2 having a telephone exchange 3a, an Internet 4 connected via gateways 6 and 7, and a switching system 5 as a switching system.

The mobile terminal device 10 is a mobile terminal device capable of performing a call and packet communication on the mobile communication network 1, and the mobile terminal device 20 is a mobile terminal device capable of performing a call and packet communication on the mobile communication network 2. The telephone device 3b is a telephone device capable of making a telephone call on the analog communication network 3. The mobile terminal device 10 can be connected to the Internet 4 via the gateway 6, and the telephone device 3 b is set to be able to connect to the Internet 4 via the gateway 7.

Each of the circuit switching networks 1a and 2b and the gateways 6 and 7 has a data conversion device, and performs conversion based on a voice coding system (for example, voice coding system 1) unique to the communication network. Function of converting the converted audio data into audio data corresponding to a different audio encoding method (for example, audio encoding method 0, etc.), and conversely, audio converted based on the different audio encoding method. It also has a function of reconverting data into voice data corresponding to a voice coding system specific to a communication network.

In the above communication system, 1) the portable terminal device 10 connects to the Internet 4 via the gateway 6, or the telephone device 3b connects to the Internet 4 via the gateway 7. 2) An Internet call is made between the portable terminal device 10 and the telephone device 3b.

An Internet call in this case will be described. The portable terminal device 10 first makes a call to the gateway 6 connected to the analog communication network 3, assuming that the communication partner is the telephone device 3 b. Next, the gateway 6 selects the gateway 7 that is a gateway for connecting the telephone device 3b to the Internet 4. Then, the gateway 7 calls the telephone device 3b.

In this case, a transmission path is established between the portable terminal device 10 and the gateway 6 and between the gateway 7 and the telephone device 3b to transmit and receive analog data. During this time, digital data is transmitted and received because the data is transmitted via the Internet 4. Then, the portable terminal device 10 and the telephone device 3b transmit and receive voice data to make a call.

Here, the manner of conversion of transmitted and received voice data will be described step by step with reference to FIG.
FIG. 3 is a sequence diagram illustrating a conversion sequence of audio data according to the present embodiment. (When the telephone device 3b is called from the mobile terminal device 10) The control unit 16 of the mobile terminal device 10 converts the voice, which is analog data, into digital data-type 1 voice data. 2. The digital data-type 1 voice data is transmitted from the portable terminal device 10 to the circuit switching network 1a. 3. In the circuit switching network 1a, digital data-type 1 voice data is converted into analog data and transmitted to the switching system 5.

4. The switching system 5 transmits the analog data to the gateway 6 via the telephone exchange 3a of the analog communication network 3. 5. The gateway 6 converts the analog data into digital data-type 0 voice data, and
To send to. 6. The gateway 7 determines that the voice data transmitted to the Internet 4 is addressed to the telephone device 3b managed by the gateway 7 and captures the voice data. And digital data-
The audio data of type 0 is converted into analog data and sent to the transmission path between the gateway 7 and the telephone device 3b which has already been established, so that the audio from the portable terminal device 10 is transmitted to the telephone device 3b.

(When the portable terminal device 10 is called from the telephone device 3b) The telephone device 3b transmits voice, which is analog data, to the gateway 7 via a transmission path between the telephone device 3b and the gateway 7. 2. The gateway 7 converts the analog data to digital data-type 0 voice data transmitted through the Internet 4 and sends the converted data to the Internet 4. 3. The gateway 6 transmits the voice data transmitted to the Internet 4 to the portable terminal 1 managed by the gateway 6 itself.
It is determined that it is addressed to 0 and is taken in. Then, the digital data-type 0 voice data is converted into analog data and sent to the transmission path between the already established gateway 6 and the portable terminal device 10.

4. The analog data is transmitted from the telephone exchange 3a to the circuit switching network 1a of the mobile communication network 1 via the switching system 5. 5. In the circuit switching network 1a, the analog data is converted into digital data-type 1 voice data and transmitted to the portable terminal device 10. 6. The control unit 16 of the mobile terminal device 10 converts the received digital data-type 1 voice data into voice that is analog data, so that voice from the telephone device 3b is transmitted to the mobile terminal device 10.

[Second Embodiment] FIG. 4 is a system configuration diagram showing the configuration of a communication system according to a second embodiment. In this communication system, the same reference numerals are given to the same components as those of the communication system of the first embodiment. However, in this embodiment, the packet networks 1b of the mobile communication network 1 and the packet networks of the mobile communication network 2 are used. Each of the networks 2b is directly connected to the Internet 4. The portable terminal device 10 can be connected to the Internet 4 via the packet network 1b, and the telephone device 3b can be connected to the Internet 4 via the gateway 7.

In the communication system of this embodiment, 1) the portable terminal device 10 connects to the Internet 4 via the packet network 1b, or the telephone device 3b connects to the Internet 4 via the gateway 7. 2) An Internet call is made between the portable terminal device 10 and the telephone device 3b. 3) The mobile terminal device 10 supports the audio encoding method 0 in addition to the audio encoding method 1, and can convert audio data based on the audio encoding method 0.

The Internet call in this case will be described. The mobile terminal device 10 connects to the Internet 4 from the packet network 1b, and the gateway 7 is a gateway for the telephone device 3b to connect to the Internet 4.
Select Then, the gateway 7 becomes the telephone device 3
Call b.

In this case, the gateway 7 and the telephone device 3b
, A transmission path is established to transmit and receive analog data, but between the packet network 1 b and the gateway 7,
Digital data transmission / reception is performed through the Internet 4. Then, the portable terminal device 10 and the telephone device 3b transmit and receive voice data to make a call.

Here, the state of conversion of transmitted and received voice data will be described step by step with reference to FIG.
FIG. 5 is a sequence diagram illustrating a conversion sequence of audio data according to the present embodiment. (When the telephone device 3b is called from the mobile terminal device 10) The control unit 16 of the mobile terminal device 10 converts the audio that is analog data into digital data-type 0 audio data. 2. The digital data-type 0 voice data is transmitted from the portable terminal device 10 to the packet network 1b with the telephone device 3b as a destination. 3. The digital data-type 0 voice data is transmitted to the Internet 4 from the packet network 1b.

4. Gateway 7 is the Internet 4
Is determined to be addressed to the telephone device 3b managed by itself, and is taken in. Then, the digital data-type 0 voice data is converted into analog data and sent to the transmission path between the gateway 7 and the telephone device 3b which has already been established.
Is transmitted to the telephone device 3b.

(When the portable terminal device 10 is called from the telephone device 3b) The telephone device 3b transmits voice, which is analog data, to the gateway 7 via a transmission path between the telephone device 3b and the gateway 7. 2. The gateway 7 converts the analog data to digital data-type 0 voice data transmitted through the Internet 4 and sends the converted data to the Internet 4. 3. The packet network 1b transmits the voice data transmitted to the Internet 4 to the portable terminal device 1 managed by itself.
It is determined that it is addressed to 0 and is taken in. Then, the digital data-type 0 voice data is transmitted to the portable terminal device 10.

4. The control unit 16 of the mobile terminal device 10 converts the received digital data-type 0 voice data into voice, which is analog data, so that voice from the telephone device 3b is transmitted to the mobile terminal device 10. The above is the basic operation in the present embodiment.

Further, by using only the voice coding scheme 0 for voice data transmitted on the Internet 4 as the voice coding scheme in the portable terminal device 10, the voice coding scheme of the mobile communication network 1 can be used. May be a mobile terminal device 10 dedicated to Internet calls that does not support the above.

In this case, the packet network 1b sends out voice data of the voice coding system 0 transmitted from the mobile terminal device 10 to the Internet 4, so that the mobile terminal device 10 can make an Internet call. Also, the audio coding method in the control unit 16 of the mobile terminal device 10 is as follows:
Since only the audio coding method 0 is used, the configuration of the control unit 16 and the control program in the control unit 16 are simplified, so that the low-cost mobile terminal device 10 can be provided.

The operation unit 15 of the portable terminal device 10 is
It is also possible to function as a selection unit for selecting an Internet call and a call in the mobile communication network 1. By operating the operation unit 15 as a selection unit, the user of the mobile terminal device 10 can easily select an Internet call and a call in the mobile communication network 1.

[Third Embodiment] Similarly, a call system according to the present embodiment will be described with reference to FIG. The communication system according to the present embodiment has basically the same configuration as the communication system according to the second embodiment.
Can be connected to the Internet 4 via the packet network 1b, and the portable terminal device 20 is set to be able to connect to the Internet 4 via the packet network 2b.

In the communication system of this embodiment, 1) the portable terminal device 10 connects to the Internet 4 via the packet network 1b, or the portable terminal device 20 connects to the Internet 4 via the packet network 2b. 2) An Internet call is made between the portable terminal device 10 and the portable terminal device 20. 3) The mobile terminal device 10 supports the audio encoding method 0 in addition to the audio encoding method 1, and can convert audio data based on the audio encoding method 0. Further, the portable terminal device 20
Supports audio encoding method 0 in addition to audio encoding method 2, and can convert audio data based on audio encoding method 0. Therefore, the audio coding method commonly used in the mobile terminal devices 10 and 20 is the audio coding method 0.

An Internet call in this case will be described. The mobile terminal device 10 connects to the Internet 4 from the packet network 1b, and selects the packet network 2b for the mobile terminal device 20 to connect to the Internet 4. Then, the packet network 2b calls the mobile terminal device 20.

In this case, the packet network 1b and the packet network 2
b, digital data is transmitted and received because the data is transmitted via the Internet 4. Then, the portable terminal device 10 and the telephone device 3b transmit and receive voice data to make a call.

Here, the manner of conversion of transmitted and received voice data will be described step by step with reference to FIG.
FIG. 6 is a sequence diagram illustrating a conversion sequence of audio data according to the present embodiment. (When the mobile terminal device 20 calls the mobile terminal device 20) The control unit 16 of the mobile terminal device 10 converts the audio that is analog data into digital data-type 0 audio data. 2. From the portable terminal device 10 to the packet network 1b, with the portable terminal device 20 as the destination, the digital data-type 0
Is transmitted. 3. The digital data-type 0 voice data is transmitted to the Internet 4 from the packet network 1b.

4. The packet network 2b is connected to the Internet 4
It is determined that the voice data transmitted to the mobile terminal device 20 is addressed to the mobile terminal device 20 managed by itself, and the digital data-type 0 voice data is transmitted to the mobile terminal device 20. 5. The control unit of the mobile terminal device 20 converts the received digital data-type 0 voice data into voice, which is analog data, and transmits the voice from the mobile terminal device 10 to the mobile terminal device 20.

(From the portable terminal device 20 to the portable terminal device 10)
Is called) 1. The control unit of the portable terminal device 20 converts the voice, which is analog data, into digital data-type 0 voice data. 2. From the portable terminal device 20 to the packet network 2b, with the portable terminal device 10 as a destination, the digital data-type 0
Is transmitted. 3. The digital data-type 0 voice data is transmitted from the packet network 2b to the Internet 4.

4. The packet network 1b is connected to the Internet 4
It is determined that the voice data sent to the mobile terminal device 10 is addressed to the mobile terminal device 10 managed by itself, and the digital data type 0 voice data is transmitted to the mobile terminal device 10. 5. The control unit 16 of the mobile terminal device 10 converts the digital data-type 0 voice data into analog data, and outputs the voice from the mobile terminal device 20 to the mobile terminal device 10.
It is transmitted to.

[Fourth Embodiment] Next, a call system according to this embodiment will be described with reference to FIG. The communication system according to the present embodiment has basically the same configuration as the communication system according to the second embodiment.
0 corresponds to the speech coding method 1, and the packet network 1b
It has an audio data conversion function to be described later.

In the communication system according to the present embodiment, 1) the portable terminal device 10 connects to the Internet 4 via the packet network 1b, or the telephone device 3b connects to the Internet 4 via the gateway 7. 2) An Internet call is made between the portable terminal device 10 and the telephone device 3b. 3) The packet network 1b converts the digital data from the mobile terminal device 10 into the digital data
It is possible to convert to digital data-type 0 audio data, and conversely, to convert digital data-type 0 audio data to digital data-type 1 audio data and transmit it to the portable terminal device 10.

The conversion of voice data transmitted and received in an Internet call in this case will be described step by step with reference to FIG. FIG. 7 is a sequence diagram illustrating a conversion sequence of audio data according to the present embodiment. (When the telephone device 3b is called from the mobile terminal device 10) The control unit 16 of the mobile terminal device 10 converts the voice, which is analog data, into digital data-type 1 voice data. 2. The digital data-type 1 voice data is transmitted from the portable terminal device 10 to the packet network 1b with the telephone device 3b as a destination. 3. The packet network 1 b converts the digital data-type 1 voice data into digital data-type 0 voice data, and sends the digital data-type 0 voice data to the Internet 4.

4. Gateway 7 is the Internet 4
Is determined to be addressed to the telephone device 3b managed by itself, and is taken in. Then, the digital data-type 0 voice data is converted into analog data and sent to the transmission path between the gateway 7 and the telephone device 3b which has already been established.
Is transmitted to the telephone device 3b.

(When the portable terminal device 10 is called from the telephone device 3b) The telephone device 3b transmits voice, which is analog data, to the gateway 7 via a transmission path between the telephone device 3b and the gateway 7. 2. The gateway 7 converts the analog data to digital data-type 0 voice data transmitted through the Internet 4 and sends the converted data to the Internet 4. 3. The packet network 1b transmits the voice data transmitted to the Internet 4 to the portable terminal device 1 managed by itself.
It is determined that it is addressed to 0 and is taken in. Then, the digital data-type 0 audio data is converted into digital data-type 1 audio data and transmitted to the portable terminal device 10.

4. The control unit 16 of the mobile terminal device 10 converts the received digital data-type 1 voice data into voice that is analog data, so that voice from the telephone device 3b is transmitted to the mobile terminal device 10.

[Fifth Embodiment] Next, a call system according to the present embodiment will be described with reference to FIG. The communication system according to the present embodiment has basically the same configuration as the communication system according to the third embodiment.
0 corresponds to the speech encoding method 1 and the portable terminal device 20
Corresponds to the speech encoding system 2, and the packet networks 1b, 2b
Has an audio data conversion function to be described later.

In the communication system of the present embodiment, 1) The portable terminal device 10 connects to the Internet 4 via the packet network 1b, or the portable terminal device 20 connects to the Internet 4 via the packet network 2b. 2) An Internet call is made between the portable terminal device 10 and the portable terminal device 20.

3) The packet network 1b is connected to the portable terminal 10
To convert digital data-type 1 voice data into digital data-type 0 voice data, and vice versa, convert digital data-type 0 voice data to digital data-type 1 voice data. It is possible to transmit to the portable terminal device 10. Further, the packet network 2b converts the digital data-type 2 voice data from the portable terminal device 20 into a digital data-type 0
, And conversely, digital data-type 0 voice data can be converted to digital data-type 2 voice data and transmitted to the portable terminal device 20. It is possible to

The conversion of voice data transmitted / received in the Internet call in this case will be described one by one with reference to FIG. FIG. 8 is a sequence diagram illustrating a conversion sequence of audio data according to the present embodiment. (When the mobile terminal device 20 calls the mobile terminal device 20) The control unit 16 of the mobile terminal device 10 converts the voice, which is analog data, into digital data-type 1 voice data. 2. From the portable terminal device 10 to the packet network 1b, the digital data type 1
Is transmitted. 3. The packet network 1 b converts the digital data-type 1 voice data into digital data-type 0 voice data, and sends the digital data-type 0 voice data to the Internet 4.

4. The packet network 2b is connected to the Internet 4
It is determined that the voice data transmitted to the mobile terminal device 20 is managed by itself and is taken in. And
The digital data-type 0 audio data is converted into digital data-type 2 audio data and then transmitted to the portable terminal device 20. 5. The mobile terminal device 20 converts digital data-type 2 voice data into analog data, and the voice from the mobile terminal device 10 is transmitted to the mobile terminal device 20.

(From the portable terminal device 20 to the portable terminal device 10)
Is called) 1. The control unit of the portable terminal device 20 converts the voice, which is analog data, into digital data-type 2 voice data. 2. From the portable terminal device 20 to the packet network 2b, the digital data-type 2
Is transmitted. 3. The packet network 2 b converts the digital data-type 2 voice data into digital data-type 0 voice data, and sends the digital data-type 0 voice data to the Internet 4.

4. The packet network 1b is connected to the Internet 4
The voice data sent to the mobile terminal device 10 is determined to be addressed to the mobile terminal device 10 managed by itself, and is taken in. And
The digital data-type 0 audio data is converted into digital data-type 1 audio data and then transmitted to the portable terminal device 10. 5. The mobile terminal device 10 converts digital data-type 1 voice data into analog data, and the voice from the mobile terminal device 10 is transmitted to the mobile terminal device 20.

[0068]

According to the portable terminal device, when the portable terminal device can be connected to the Internet, the speech encoding unit converts the speech into speech data transmitted on the Internet and transmits the speech data from the Internet. Since voice data is converted to voice, Internet communication can be performed with the portable terminal device alone. In addition, since the Internet call is made possible, the call charge can be kept low, for example, even for a call to a foreign country where the call charge is high, while maintaining the advantage of excellent portability.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a portable terminal device.

FIG. 2 is a system configuration diagram illustrating a configuration of a call system according to the first embodiment.

FIG. 3 is a sequence diagram illustrating a conversion sequence of audio data according to the first embodiment.

FIG. 4 is a system configuration diagram illustrating a configuration of a call system according to a second embodiment.

FIG. 5 is a sequence diagram showing a conversion sequence of audio data according to the second embodiment.

FIG. 6 is a sequence diagram illustrating a conversion sequence of audio data according to the third embodiment.

FIG. 7 is a sequence diagram illustrating a conversion sequence of audio data according to a fourth embodiment.

FIG. 8 is a sequence diagram showing a conversion sequence of audio data according to a fifth embodiment.

FIG. 9 is a list of speech coding schemes corresponding to a mobile communication network.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1, 2 Mobile communication network 1a, 2a Circuit switching network 1b, 1b Packet network 3 Analog communication network 3a Telephone exchange station 3b Telephone device 4 Internet 5 Switching system 6, 7 Gateway 10, 20 Mobile terminal device 11 Antenna 12 Transmitter / receiver 13 Display Unit 14 Voice input / output unit 15 Operation unit 16 Control unit

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5K027 AA11 BB01 CC08 5K030 HA01 HA08 HB01 HB18 HC01 HC09 HD03 JL01 JT01 JT09 KA19 LA07 LB13 5K067 AA21 AA29 BB02 BB21 EE02 EE16 GG01 HH05 HH21 NN03 NN02 NN02 UU16 UU19

Claims (6)

[Claims] 1. A portable terminal device that can be connected to the Internet from a mobile communication network, a function of converting voice into voice data of a voice coding system transmitted on the Internet, and the voice coding system transmitted from the Internet. A mobile terminal device comprising: a voice encoding unit having a function of converting voice data into voice. 2. The mobile terminal device according to claim 1, wherein the voice coding unit performs conversion for a plurality of different voice coding schemes. 3. The speech encoding unit according to claim 1, wherein the speech encoding unit has a speech encoding scheme commonly used in a communication network different from the mobile communication network of the portable terminal device. 3. The mobile terminal device according to 2. 4. The portable terminal device according to claim 1, wherein the audio encoding unit has only the audio encoding method for audio data transmitted on the Internet. 5. A communication system according to claim 1, further comprising a selection unit for selecting an Internet call made via said Internet and a call in said mobile communication network.
The mobile terminal device according to any one of claims 4 to 4. 6. A data conversion device connectable to the Internet, the function of reconverting voice data converted based on a voice coding system specific to a communication network into voice data corresponding to a different voice coding system. A function of re-converting the voice data converted based on the different voice coding scheme into the voice data corresponding to the voice coding scheme specific to the communication network.