KR20030083267A - Method and system for digital voice communication - Google Patents

Abstract

PURPOSE: A method for performing digital voice communication is provided to transceive a voice by using a data communication service method between a wire terminal and a wireless terminal without correcting a mobile communication system of a communication provider, thereby enhancing clear and safe voice quality. CONSTITUTION: A wireless terminal(40) performs a voice communication service and a data communication service by using a CDMA system. A mobile communication network(42) transmits data between the wireless terminal(40) and an IWF(44). The IWF(44) processes data connections between the mobile communication network(42) and a wire communication network(46). The wire communication network(46) transmits data between the IWF(44) and a wire terminal(48), and includes an exchange. The wire terminal(48) comprises as follows. A voice communication processor(48d) performs the voice communication service. A vocoder(48a) encodes/decodes a voice signal/voice data. An input/output unit(48b) inputs/outputs the voice data. A controller(48c) determines to perform either of the voice communication service and the data communication service.

Description

Method and system for digital voice communication

The present invention relates to a digital voice communication method using a code division multiple access (CDMA) mobile communication system, and more particularly, to a digital voice communication method for transmitting and receiving voice between a wireless terminal and a wired terminal in a data communication method.

The CDMA mobile communication system is a mobile communication system using a code division multiple access method. The transmission of voice or data from a base station to a wireless terminal is called a forward traffic channel, and the voice or data is transmitted from the wireless terminal to the base station. This is called a reverse traffic channel.

The service using the CDMA mobile communication system includes a voice communication service capable of transmitting and receiving voice and a data communication service capable of transmitting and receiving data. For example, a data communication service corresponds to a service capable of accessing the Internet using a wireless terminal and transmitting and receiving information.

Hereinafter, a CDMA mobile communication system using the IS-95, IS-95A, and IS-95B systems will be described with reference to FIGS. 1 to 3.

1 is a block diagram illustrating a reverse traffic channel of a CDMA mobile communication system according to the prior art. In the case of transmitting voice, the reverse traffic channel uses a vocoder 10 to convert a voice of a caller into a predetermined size of information bit ( When the packet data is generated by compressing the bits, the convolutional encoder 12 adds a frame quality indicator and an encoder tail bit to the packet data generated by the vocoder. Frame structure and encode them. Thereafter, the signal is spread through the symbol repeater 14, the block interleaver 16, and the spreading and modulator 18, and transmitted to the base station through the assigned frequency band.

FIG. 2 is a block diagram illustrating a forward traffic channel of a CDMA mobile communication system according to the prior art, and is a reverse process of the process shown in FIG. In the case of transmitting voice, the forward traffic channel receives a signal from the base station, passes the despreading and demodulator 20, the block deinterleaver 22, the symbol extractor 24, and the convolutional decoder 26, and transmits original information bits. After recovering the communication, the vocoder 28 restores the information bits to voice.

In such a CDMA mobile communication system, a voice communication service between a wireless terminal and a wired terminal can be implemented as shown in FIG. 3.

3 is a block diagram illustrating a communication network between a wireless terminal and a wired terminal according to the prior art. Here, the base station controller (BSC) 31 outputs a vocoder output coded by a QCLP (Qualcomm Code Excited Linear Prediction) or EVRC (Enhanced Variable Rate Coder) method in the wireless terminal 30. Converted to the information bits encoded by the Coder and Decoder method and transmitted to the Mobile Switching Center (MSC) 32, and the wired terminal 35 through the Public Switched Telephone Network (PSTN) network 33 and the switch 34. If the transmission to the wired terminal 35 is converted to the original voice to communicate.

However, in order to provide information protection service for voice communication between the wireless terminal and the wired terminal, it is advantageous to use a data communication service method.

In brief, a data communication service method of a CDMA wireless terminal, a vocoder compresses an input signal into information bits having a predetermined size to generate packet data, and the data processing unit uses TCP to process the generated packet information bits without delay. (Transmission Control Protocol) processing, IP (Internet Protocol) processing IP protocol processing, PPP (Point-to-Point Protocol) processing PPP protocol processing, RLP (Radio Link Protocol) processing RLP protocol processing The transmission proceeds.

Attempts have been made to perform voice communication using such a data communication service method. For example, US Pat. No. 5,963,621 provides a method for protecting voice data using a secure wired telephone in a network to which a modem is connected.

However, in order to implement a voice communication service between a wireless terminal and a wired terminal using such a data communication service method, there is a problem in that a mobile communication system needs to be modified with the help of a communication service provider. .

SUMMARY OF THE INVENTION The present invention has been made in an effort to provide a digital voice communication system and method for transmitting and receiving voice using a data communication service method between a wired terminal and a wireless terminal without modifying a mobile communication system of a communication service provider.

Another technical problem to be achieved by the present invention is to provide a digital voice communication system and method that can improve sound quality, enhance security, and have excellent recoverability.

1 is a block diagram illustrating a reverse traffic channel of a conventional CDMA mobile communication system.

2 is a block diagram illustrating a forward traffic channel of a conventional CDMA mobile communication system.

3 is a block diagram illustrating a communication network between a wireless terminal and a wired terminal according to the prior art.

4 is a block diagram illustrating a digital voice communication system according to an embodiment of the present invention.

5 is a flowchart illustrating a digital voice communication method according to an embodiment of the present invention.

6 is a diagram illustrating a process of preparing digital voice communication between a wireless terminal and a wired terminal.

FIG. 7 is a flowchart for explaining a preferred embodiment of the present invention with respect to step 51 illustrated in FIG.

In order to achieve the above object, the digital voice communication system according to the present invention provides a voice communication service and a data communication service using a CDMA method in a digital voice communication for transmitting and receiving voice using a data communication service method between a wireless terminal and a wired terminal. Wireless terminal to perform; A mobile communication network for transferring data between the wireless terminal and the IWF; An IWF which handles the connection of data between the mobile communication network and the wired communication network; A wired communication network for transferring data between an IWF and the wired terminal and including a switch; And a wired terminal that performs a voice communication service and a data communication service.

In order to achieve the above object, the digital voice communication method according to the present invention is a wireless terminal, a mobile communication network, a wired communication network, an IWF for processing data connection between a mobile communication network and a wired communication network, and a wired terminal for performing a voice communication service and a data communication service. A digital voice communication method for transmitting and receiving voice using a digital voice communication system, comprising: establishing a voice communication call between a wireless terminal and a wired terminal through a mobile communication network, an IWF, and a wired communication network; Determining whether the wired terminal can process digital voice communication; If it is determined that the wired terminal can process digital voice communication, the wireless terminal disconnects the voice communication call with the wired terminal; Establishing a data communication call between a wireless terminal and a wired terminal through a mobile communication network, an IWF, and a wired communication network; Determining, by the IWF and the wired terminal, the data transmission rate; And performing digital voice communication between the wireless terminal and the wired terminal.

Hereinafter, a digital voice communication system according to an embodiment of the present invention will be described with reference to the accompanying drawings. However, the following embodiments are provided to those skilled in the art to fully understand the present invention, and may be modified in various forms, and the scope of the present invention is limited to the embodiments described below. It doesn't happen.

4 is a block diagram illustrating a digital voice communication system according to an embodiment of the present invention, wherein the wireless terminal 40, the mobile communication network 42, the IWF 44, the wired communication network 46, and the wired terminal 48 are described. It consists of

Such a digital voice communication system of FIG. 4 illustrates only a configuration necessary for implementing voice communication between a CDMA wireless terminal and a wired terminal through a data communication service method. It is also possible to perform a voice communication service method between wired terminals.

First, the wireless terminal 40 includes a vocoder 40a, a data processor 40b, and an input / output unit 40c.

The vocoder 40a encodes a voice signal into information bits of a predetermined size to generate packet data or to restore voice from the packet data.

The data processor 40b processes the packet data through TCP (Transmission Control Protocol), IP (Internet Protocol), PPP (Point-to-Point Protocol), RLP (Radio Link Protocol), and through the input / output unit 40c. It transmits to the base station 42a of the mobile communication network 42. TCP / IP is a communication protocol used in the Internet. When the voice is transmitted from the wireless terminal 40, the present invention uses the TCP / IP protocol because it uses a data communication method rather than a voice communication method. On the contrary, when the wireless terminal 40 receives the voice from the base station 42a of the mobile communication network 42, the wireless terminal 40 becomes the reverse process of transmitting the voice to the base station 42a. That is, when data is received from the base station 42a through the input / output unit 40c, the data processing unit 40b performs RLP processing, PPP processing, IP processing, and TCP processing, and the vocoder 40a restores the original voice.

The mobile communication network 42 transfers the data transmitted from the wireless terminal 40 to the IWF (Inter Working Function) 44, and the base station 42a, the base station controller 42b, and the mobile switching center 42c. It is configured to include. The mobile communication network 42 is configured to provide a voice communication service and a data communication service in a conventional CDMA mobile communication system, and the base station 42a is an antenna for transmitting and receiving data from the wireless terminal 40 to a wired network. , Towers and other wireless equipment can be configured. In addition, the base station controller 42b controls the base station to process the transmitted and received data. The base station controller 42b controls wireless base station registration, channel assignment, hand off, call setup and termination, etc., in the cell by the base station. Plays the role of. The mobile exchange 42c is connected to the base station 42a and the IWF 44 to provide a switching function.

On the other hand, the IWF 44 processes the connection of data between the mobile communication network 42 and the wired communication network 46. That is, in order to recognize the data transmitted through the mobile communication network 42 in the wired communication network 46, an input / output unit (not shown) such as a modem, an IWF control unit (not shown), a protocol processing unit (not shown) by itself. The back is built.

For the data communication service provided by the CDMA mobile communication system, for example, as defined in the IS-95 standard, the base station should not convert QCELP or EVRC data into PCM. Therefore, in case of a CDMA communication service provider, a vocoder bypass is determined based on the control bit for distinguishing voice and data from a system for a data communication service. The IWF 44 handles the functions necessary to provide data communication services in such a CDMA mobile communication system. Accordingly, the IWF may include a TCP processor (not shown), an IP processor (not shown), a PPP processor (not shown), and the like as a protocol processor (not shown). In this case, since the IWF 44 is connected to the existing wired communication network, an incoming service in which the wireless terminal receives a call as well as an outgoing service in which the wireless terminal makes a call is possible. That is, communication can be made from both the wireless terminal and the wired terminal.

The wired communication network 46 serves to transfer data between the IWF 44 and the wired terminal 48. The wired communication network 46 corresponds to a public switched telephone network (PSTN) network, which is a general telephone network. The wired communication network 46 may itself include an exchange (not shown).

On the other hand, the wired terminal 48 is a terminal capable of performing both a voice communication service and a data communication service, unlike a general wired telephone, and includes a vocoder 48a, an input / output unit 48b, a controller 48c, and a voice communication processor ( 48d).

First, when transmitting voice data to the wired communication network 46 through a data communication service method, the vocoder 48a of the wired terminal 48 encodes the voice into information bits having a predetermined size to generate packet data, and then processes the packet data. The control bit is pasted to the wired communication network 46 via the input / output unit 48b. On the contrary, however, when voice data is received from the wired communication network 46 to the wired terminal 48, the reverse process of the voice transmission is performed. That is, when a signal is received through the input / output unit 48b of the wired terminal 48, the packet data is generated from the received signal and the sequence control bits are checked, and the vocoder 48a converts the inspected packet data into voice. .

If voice is transmitted and received using a voice communication service method rather than a data communication service, the voice communication processing unit 48d is used. Here, the control unit 48c of the wired terminal 48 plays a role in determining which of the voice communication service and the data communication service.

Hereinafter, a digital voice communication method according to an embodiment of the present invention will be described with reference to the accompanying drawings.

5 is a flowchart illustrating a digital voice communication method according to an embodiment of the present invention, the method comprising preparing for digital voice communication between a wired terminal and a wireless terminal and executing digital voice communication (50th to 55th). Step).

First, a voice communication call is established between a wireless terminal and a wired terminal through a mobile communication network, an IWF, and a wired communication network (step 50). In the digital voice communication method, voice is transmitted and received using a data communication method, but before the wired terminal 48 and the wireless terminal 40 establish a call for data communication, a voice communication call is first established for data communication. Be prepared. Since the wired terminal 48 is a terminal capable of performing both data communication and voice communication, the voice communication call is set up using the voice communication processing unit 48d and the control unit 48c of the wired terminal 48.

When the voice communication call is established, it is determined whether the wired terminal can process digital voice communication (step 51).

The wired terminal 48 according to the present invention includes a vocoder 48a and an input / output unit 48b to enable data communication. The vocoder 48a functions to generate voice data by encoding the voice signal or to reproduce the voice signal by decoding the voice data input from the input / output unit 48b, and the input / output unit 48b transmits the voice data to the wired communication network 46. Or to the wired communication network 46. Therefore, a procedure for confirming whether the wired terminal 48 can handle digital communication is required before establishing a data communication call.

Hereinafter, operation 51 of FIG. 5 will be described in more detail with reference to FIG. 7.

FIG. 7 is a flowchart for explaining a preferred embodiment of the present invention with respect to the fifty-first step shown in FIG. 5, wherein the wireless terminal 40 transmits a signal for confirming that digital voice communication is possible to the wired terminal 48. When transmitting, the wired terminal 48 is configured to give a voice answer (steps 51-1 to 51-4).

First, a signal confirming whether or not the wireless terminal 40 can process digital voice communication is transmitted to the wired terminal 48 (step 51-1). To this end, the wireless terminal 40 performs step 51-1 by transmitting a predetermined number of DTMF signals among dual tone multi-frequancy (DTMF) signals in a frequency band not used in a key of the wireless terminal to the wired terminal 48 a predetermined number of times. Can be implemented. Here, the DTMF signal is a complex frequency code transmitted from a wired or wireless terminal. In order to check whether the wired terminal is capable of digital voice communication, the wireless terminal transmits a DTMF signal of a frequency band not used by the keypad of the wireless terminal to the wired terminal. Send. At this time, the transmission of the DTMF signal may transmit a predetermined number of times continuously in order to minimize the case of not recognizing the error.

After step 51-1, the wired terminal 48 determines whether digital voice communication can be processed (step 51-2). At this time, if it is determined that the wired terminal 48 can process digital voice communication, a signal indicating that digital voice communication is possible is transmitted to the wireless terminal 40 (step 51-3). If it is determined that the wired terminal 48 cannot process digital voice communication, a signal indicating that digital voice communication is impossible is transmitted to the wireless terminal 40 (step 51-4).

To this end, the wired terminal 48 transmits a predetermined frequency band DTMF signal of the frequency band DTMF signals not used in the key of the wired terminal to the wireless terminal 40 by a predetermined number of times 51-3 or 51-4. You can implement the steps. Here, the meaning of the DTMF signal is the same as described in step 51-1.

Next, operation 52 will be described with reference to FIG. 5.

If it is determined that the wired terminal 48 can process digital voice communication, the wireless terminal 40 disconnects the voice communication call with the wired terminal 48 (step 52). Since the voice communication call is set up before the data communication call is set up, the voice communication call is cut to set up the data communication call.

After step 52, a data communication call is established between the wireless terminal 40 and the wired terminal 48 (step 53). The data communication call can be set up according to, for example, a call setup procedure defined in the IS-99 (international standard). FIG. 6 is a view for explaining a process of preparing digital voice communication between a wireless terminal and a wired terminal. Referring to FIG. 6, when the wireless terminal 40 requests a data communication call from the mobile switching station 42c, the mobile switching unit changes. 42c connects the wireless terminal 40 with the IWF 44 and sends a bypass command to the base station controller 42b. In this case, the reason for transmitting the bypass command is that, as described above in the IWF 44 of FIG. 4, the base station should not convert the QCELP or EVRC data into the PCM for the data communication service.

After operation 53, the IWF and the wired terminal determine the data transmission rate (step 54). The IWF 44 and the wired terminal 48 may negotiate with each other to set the data transmission rate at the highest or optimal value according to the line state. Referring to FIG. 6, a method of setting a transmission rate may include, for example, a mobile switchboard 42c requesting a wired communication call to a wired terminal 48, and receiving a response from the wired terminal 48 when the wired terminal 48 receives an IWF ( 44). The transmission rate is then negotiated between the IWF 44 and the wired terminal 48. Negotiation of the transmission rate can be set to meet the condition if either the IWF 44 or the wired terminal 48 proposes a condition of a specific rate.

When the transmission speed is determined, the data channel setting is completed, so that the wireless terminal and the wired terminal execute digital voice communication (step 55). Since digital voice communication transmits and receives voices through a data communication service method as described above, the wired terminal 48 supporting data communication with the wireless terminal 40 includes a mobile communication network 42, an IWF 44, and a wired communication network. If the data channel is set via 46, it is realized by transmitting and receiving voice.

As described above, the digital voice communication method and system according to the present invention have an effect of providing a digital voice communication service between a wired terminal and a wireless terminal independently without modifying a mobile communication network of a communication operator, and using a data communication protocol. Since the voice is encrypted and transmitted and received, the sound quality is clean and security is enhanced. As mentioned above, although the present invention has been described in detail with reference to preferred embodiments, the present invention is not limited to the above embodiments, and various modifications may be made by those skilled in the art within the scope of the technical idea of the present invention. This is possible.

Claims (8)

In digital voice communication between a wireless terminal and a wired terminal, voice transmission and reception using a data communication service method, A wireless terminal performing a voice communication service and a data communication service using a CDMA scheme; A mobile communication network for transferring data between the wireless terminal and an IWF; An IWF for handling data connection between the mobile communication network and a wired communication network; A wired communication network transferring data between the IWF and the wired terminal and including a switch; And A wired line having a voice communication processor for performing a voice communication service, a vocoder for encoding / decoding voice signals / voice data, an input / output unit for inputting / outputting the voice data, and a controller for determining whether to perform a voice communication service or a data communication service. Digital voice communication system comprising a terminal. The method of claim 1, wherein the wireless terminal, A vocoder for encoding / decoding voice signals / voice data; A data processor which processes the voice data by a voice communication protocol or a data communication protocol; And And an input / output unit for inputting and outputting the processed data. The method of claim 1, wherein the mobile communication network, A base station for transmitting and receiving data from the wireless terminal; A base station controller controlling a base station to process the transmitted and received data; And And a mobile exchange which transmits and receives the processed data to the IWF. The data processing unit according to claim 2, wherein Processing the voice data by a data communication protocol includes TCP processing, IP processing, PPP processing, and RLP processing. Sending / receiving voice using a digital voice communication system comprising a wireless terminal, a mobile communication network, a wired communication network, an IWF for processing data connection between the mobile communication network and a wired communication network, and a wired terminal for performing a voice communication service and a data communication service. In the digital voice communication method, (a) establishing a voice communication call between the wireless terminal and the wired terminal through the mobile communication network, the IWF and the wired communication network; (b) determining whether the wired terminal can process digital voice communication; (c) if it is determined that the wired terminal can process digital voice communication, the wireless terminal disconnecting the voice communication call with the wired terminal; (d) establishing a data communication call between the wireless terminal and the wired terminal through the mobile communication network, the IWF and the wired communication network; (e) determining, by the IWF and the wired terminal, a data transmission rate; And and (f) executing digital voice communication between the wireless terminal and the wired terminal. The method of claim 5, wherein step (b) comprises: (b1) transmitting a signal to the wired terminal confirming whether the wireless terminal can process digital voice communication; (b2) determining whether the wired terminal can process digital voice communication; (b3) if it is determined that the wired terminal can process digital voice communication, transmitting a signal to the wireless terminal indicating that digital voice communication is possible; And and (b4) if it is determined that the wired terminal cannot process digital voice communication, transmitting a signal to the wireless terminal indicating that digital voice communication is impossible. The method of claim 6, wherein step (b1), Characterized in that the wireless terminal transmits a predetermined frequency band DTMF signal of the frequency band DTMF signals not used in the key of the wireless terminal to the wired terminal a predetermined number of times, And the DTMF signal is a complex frequency code transmitted from a terminal. The method of claim 6, wherein (b3) or (b4) step, Characterized in that the wired terminal transmits a predetermined frequency band DTMF signal of the frequency band DTMF signals not used in the key of the wired terminal to the wireless terminal a predetermined number of times, And the DTMF signal is a complex frequency code transmitted from a terminal.