KR20130004996A - Method for performing voip communication between hetrogenous networks and apparatus therefor - Google Patents

Abstract

PURPOSE: A VoIP communication method and an apparatus for the same are provided to induce VoIP communication to a WiFi(Wireless Fidelity) system having a stable communication channel. CONSTITUTION: A WiFi network(300) is registered to a WiFi network of a terminal B(505). A success response message is transmitted to the terminal B. The terminal B transmits a message to be transmitted to the WiFi network(506). An LTE network transfers a message to a WiFi network(507). The WiFi network transfers a message to a terminal A(508). The terminal A retransmits an INVITE message to a terminal B(509,510). The terminal B transmits a response message through a WiFi network(511,512). [Reference numerals] (AA) Terminal A; (BB) Terminal B; (CC) Sleep state after being registered to WiFi network = WiFi connection off

Description

종 ｏＩＰ communication method between heterogeneous networks and device therefor {METHOD FOR PERFORMING VoIP COMMUNICATION BETWEEN HETROGENOUS NETWORKS AND APPARATUS THEREFOR}

The present invention relates to Voice over Internet Protocol (VoIP) communications. More specifically, the present invention relates to a VoIP communication method between heterogeneous networks and an apparatus therefor.

Prior to describing the present invention, a brief description will be given of Voice over Internet Protocol (VoIP) communication.

VoIP traffic is characterized by being generated with a fixed size with a fixed period in the VoIP codec. In addition, the VoIP communication may be divided into a talk-spurt state in which a call is in progress between users and a silence period in which the user is not speaking, and the silence period may be divided in a general call session. Account for more than 50%.

Therefore, various voice codecs are used to allocate different amounts of bandwidth to the call interval and the silence interval, which are representative of the adaptation used in the Global System for Mobile communication (GSM) and Universal Mobile Telecommunications System (UMTS). Adaptive Multi-Rate (AMR), G.723 and G.729, and G.711 used in WiFi systems.

Since voice data is not generated in the silent section, if bandwidth is allocated to the silent section, resources may be wasted accordingly. To prevent this, VoIP supports silence suppression. According to the silence suppression technique, a vocoder generating VoIP traffic does not generate traffic during the silence period, and periodically generates comfort noise to inform the other user that the call is maintained. . For example, the vocoder using the above-described codec generates a packet having a fixed size once every 20ms in a call section, and generates a noise packet every 160m in a silence section. In this case, the confirmation noise may have the form of a Silence InDicator frame.

An object of the present invention is to provide a method for heterogeneous VoIP communication and an apparatus therefor.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are not restrictive of the invention, unless further departing from the spirit and scope of the invention as defined by the appended claims. It will be possible.

In a wireless communication system according to an aspect of the present invention, a method for receiving a Voice over Internet Protocol (VoIP) call of a terminal includes: receiving a call origination message through a first communication network; Transmitting a registration attempt message to a second communication network; When the registration acceptance message is received from the second communication network, transmitting a redirect request signal of the call origination message to the first communication network; Receiving the call origination message again from the second communication network; And transmitting a call accept message to the second communication network. The method may further include transmitting a call acceptance message to the first communication network when a registration rejection message is received from the second communication network or a preset time elapses after the registration attempt message is transmitted.

In another aspect of the present invention, a terminal apparatus in a wireless communication system includes: at least one wireless communication module for transmitting and receiving signals with a first communication network and a second communication network; And a processor for processing signals transmitted and received through the wireless communication module, the processor receiving a call origination message through the first communication network, transmitting a registration attempt message to the second communication network, and When a registration acceptance message is received from a communication network, a redirection request signal of the call origination message is transmitted to the first communication network, the call origination message is received again from the second communication network, and a call acceptance message is transmitted to the second communication network. The wireless communication module is controlled to transmit the signal. The processor may further include controlling the wireless communication module to transmit a call accept message to the first communication network when a registration rejection message is received from the second communication network or a preset time elapses after the registration attempt message is transmitted. It features.

The terminal or the terminal device may include a first identifier corresponding to the first communication network and a second identifier corresponding to the second communication network, and the header of the call acceptance message transmitted to the second communication network is And a second identifier corresponding to the second communication network. The header of the call accept message transmitted to the first communication network may include a first identifier corresponding to the first communication network.

Further, when the first communication network receives the redirect request signal, the first communication network may forward the call origination message to the second communication network.

Preferably, the first communication network is a LTE (Long Term Evolution) network, the second communication network is characterized in that the WiFi (Wireless Fidelity) communication network.

A terminal according to embodiments of the present invention can effectively provide VoIP communication between heterogeneous networks. Specifically, the terminal may induce VoIP communication to a WiFi (Wireless Fidelity) system that is free or inexpensive and the communication channel is relatively stable, thereby providing efficient VoIP communication.

The effects obtained by the present invention are not limited to the above-mentioned effects, and other effects not mentioned can be clearly understood by those skilled in the art from the following description will be.

1 is a block diagram of a mobile terminal according to an embodiment of the present invention.
2 and 3 are signal flow diagrams illustrating a method for receiving a VoIP call according to a first embodiment of the present invention.
4 and 5 are signal flow diagrams illustrating a method for receiving a VoIP call according to a second embodiment of the present invention.

Hereinafter, a mobile terminal related to the present invention will be described in detail with reference to the drawings. The suffix "module" and " part "for the components used in the following description are given or mixed in consideration of ease of specification, and do not have their own meaning or role.

The mobile terminal described in this specification includes a mobile phone, a smart phone, a laptop computer, a digital broadcasting terminal, a PDA (Personal Digital Assistants), a PMP (Portable Multimedia Player), a navigation system, . However, it will be readily apparent to those skilled in the art that the configuration according to the embodiments described herein may also be applied to fixed terminals such as digital TVs, desktop computers, etc., except when applicable only to mobile terminals.

1 is a block diagram of a mobile terminal according to an embodiment of the present invention.

The mobile terminal 100 includes a wireless communication unit 110, an audio / video input unit 120, a user input unit 130, a sensing unit 140, an output unit 150, a memory 160, A controller 170, a controller 180, a power supply 190, and the like. The components shown in FIG. 1 are not essential, and a mobile terminal having more or fewer components may be implemented.

Hereinafter, the components will be described in order.

The wireless communication unit 110 may include one or more modules for enabling wireless communication between the mobile terminal 100 and the wireless communication system or between the mobile terminal 100 and the network in which the mobile terminal 100 is located. For example, the wireless communication unit 110 may include a broadcast receiving module 111, a mobile communication module 112, a wireless Internet module 113, a short range communication module 114, and a location information module 115 .

The broadcast receiving module 111 receives a broadcast signal and / or broadcast related information from an external broadcast management server through a broadcast channel.

The broadcast channel may include a satellite channel and a terrestrial channel. The broadcast management server may refer to a server for generating and transmitting broadcast signals and / or broadcast related information, or a server for receiving broadcast signals and / or broadcast related information generated by the broadcast management server and transmitting the generated broadcast signals and / or broadcast related information. The broadcast signal may include a TV broadcast signal, a radio broadcast signal, a data broadcast signal, and a broadcast signal in which a data broadcast signal is combined with a TV broadcast signal or a radio broadcast signal.

The broadcast-related information may refer to a broadcast channel, a broadcast program, or information related to a broadcast service provider. The broadcast related information may also be provided through a mobile communication network. In this case, it may be received by the mobile communication module 112.

The broadcast related information may exist in various forms. For example, it may exist in the form of Electronic Program Guide (EPG) of Digital Multimedia Broadcasting (DMB) or Electronic Service Guide (ESG) of Digital Video Broadcast-Handheld (DVB-H).

The broadcast receiving module 111 may include, for example, Digital Multimedia Broadcasting-Terrestrial (DMB-T), Digital Multimedia Broadcasting-Satellite (DMB-S), Media Forward Link Only (MediaFLO), and Digital Video Broadcast (DVB-H). Digital broadcast signals can be received using digital broadcasting systems such as Handheld and Integrated Services Digital Broadcast-Terrestrial (ISDB-T). Of course, the broadcast receiving module 111 may be adapted to other broadcasting systems as well as the digital broadcasting system described above.

The broadcast signal and / or broadcast related information received through the broadcast receiving module 111 may be stored in the memory 160.

The mobile communication module 112 transmits and receives radio signals to at least one of a base station, an external terminal, and a server on a mobile communication network. The wireless signal may include various types of data depending on a voice call signal, a video call signal or a text / multimedia message transmission / reception.

The wireless Internet module 113 is a module for wireless Internet access, and may be built in or externally attached to the mobile terminal 100. Wireless Internet technologies may include Wireless LAN (Wi-Fi), Wireless Broadband (Wibro), World Interoperability for Microwave Access (Wimax), High Speed Downlink Packet Access (HSDPA), and the like.

The short range communication module 114 refers to a module for short range communication. Bluetooth, Radio Frequency Identification (RFID), infrared data association (IrDA), Ultra Wideband (UWB), ZigBee, and the like can be used as a short range communication technology.

The position information module 115 is a module for obtaining the position of the mobile terminal, and a representative example thereof is a Global Position System (GPS) module.

Referring to FIG. 1, an A / V (Audio / Video) input unit 120 is for inputting an audio signal or a video signal, and may include a camera 121 and a microphone 122. The camera 121 processes image frames such as still images or moving images obtained by the image sensor in the video call mode or the photographing mode. The processed image frame can be displayed on the display unit 151. [

The image frame processed by the camera 121 may be stored in the memory 160 or transmitted to the outside through the wireless communication unit 110. [ Two or more cameras 121 may be provided depending on the use environment.

The microphone 122 receives an external sound signal through a microphone in a communication mode, a recording mode, a voice recognition mode, or the like, and processes it as electrical voice data. The processed voice data can be converted into a form that can be transmitted to the mobile communication base station through the mobile communication module 112 when the voice data is in the call mode, and output. Various noise reduction algorithms may be implemented in the microphone 122 to remove noise generated in receiving an external sound signal.

The user input unit 130 generates input data for a user to control the operation of the terminal. The user input unit 130 may include a key pad dome switch, a touch pad (static pressure / capacitance), a jog wheel, a jog switch, and the like.

The sensing unit 140 senses the current state of the mobile terminal 100 such as the open / close state of the mobile terminal 100, the position of the mobile terminal 100, the presence or absence of user contact, the orientation of the mobile terminal, And generates a sensing signal for controlling the operation of the mobile terminal 100. For example, when the mobile terminal 100 is in the form of a slide phone, it may sense whether the slide phone is opened or closed. In addition, whether the power supply unit 190 is supplied with power, whether the interface unit 170 is coupled to the external device may be sensed. Meanwhile, the sensing unit 140 may include a proximity sensor 141.

The output unit 150 is for generating an output relating to visual, auditory or tactile sense and includes a display unit 151, an acoustic output module 152, an alarm unit 153, a haptic module 154, 155, and the like.

The display unit 151 displays (outputs) information processed by the mobile terminal 100. For example, when the mobile terminal is in the call mode, a UI (User Interface) or a GUI (Graphic User Interface) associated with a call is displayed. When the mobile terminal 100 is in the video communication mode or the photographing mode, the photographed and / or received video or UI and GUI are displayed.

The display unit 151 includes a liquid crystal display (LCD), a thin film transistor-liquid crystal display (TFT LCD), an organic light-emitting diode (OLED), and a flexible display (flexible). and at least one of a 3D display.

Some of these displays may be transparent or light transmissive so that they can be seen through. This can be referred to as a transparent display, and a typical example of the transparent display is TOLED (Transparent OLED) and the like. The rear structure of the display unit 151 may also be of a light transmission type. With this structure, the user can see an object located behind the terminal body through the area occupied by the display unit 151 of the terminal body.

There may be two or more display units 151 according to the embodiment of the mobile terminal 100. For example, in the mobile terminal 100, a plurality of display portions may be spaced apart from one another, or may be disposed integrally with one another, and may be disposed on different surfaces, respectively.

When the display unit 151 and a sensor for detecting a touch operation (hereinafter, referred to as a touch sensor) form a mutual layer structure (hereinafter referred to as a touch screen), the display unit 151 may be configured in addition to an output device. Can also be used as an input device. The touch sensor may have the form of, for example, a touch film, a touch sheet, a touch pad, or the like.

The touch sensor may be configured to convert a change in a pressure applied to a specific portion of the display unit 151 or a capacitance generated in a specific portion of the display unit 151 into an electrical input signal. The touch sensor can be configured to detect not only the position and area to be touched but also the pressure at the time of touch.

If there is a touch input to the touch sensor, the corresponding signal (s) is sent to the touch controller. The touch controller processes the signal (s) and transmits the corresponding data to the controller 180. As a result, the controller 180 can know which area of the display unit 151 is touched.

The proximity sensor 141 may be disposed in an inner region of the mobile terminal or in the vicinity of the touch screen, which is enclosed by the touch screen. The proximity sensor refers to a sensor that detects the presence or absence of an object approaching a predetermined detection surface or a nearby object without mechanical contact using the force of an electromagnetic field or infrared rays. The proximity sensor has a longer life span than the contact sensor and its utilization is also high.

Examples of the proximity sensor include a transmission photoelectric sensor, a direct reflection photoelectric sensor, a mirror reflection photoelectric sensor, a high frequency oscillation proximity sensor, a capacitive proximity sensor, a magnetic proximity sensor, and an infrared proximity sensor. And to detect the proximity of the pointer by the change of the electric field along the proximity of the pointer when the touch screen is electrostatic. In this case, the touch screen (touch sensor) may be classified as a proximity sensor.

Hereinafter, for convenience of explanation, the act of allowing the pointer to be recognized without being in contact with the touch screen so that the pointer is located on the touch screen is referred to as a "proximity touch", and the touch The act of actually touching the pointer on the screen is called "contact touch." The position where the pointer is proximately touched on the touch screen means a position where the pointer is vertically corresponding to the touch screen when the pointer is touched.

The proximity sensor detects a proximity touch and a proximity touch pattern (e.g., a proximity touch distance, a proximity touch direction, a proximity touch speed, a proximity touch time, a proximity touch position, a proximity touch movement state, and the like). Information corresponding to the detected proximity touch operation and the proximity touch pattern may be output on the touch screen.

The sound output module 152 may output audio data received from the wireless communication unit 110 or stored in the memory 160 in a call signal reception, a call mode or a recording mode, a voice recognition mode, a broadcast reception mode, and the like. The sound output module 152 also outputs sound signals related to functions (e.g., call signal reception sound, message reception sound, etc.) performed in the mobile terminal 100. [ The audio output module 152 may include a receiver, a speaker, a buzzer, and the like.

The alarm unit 153 outputs a signal for notifying the occurrence of an event of the mobile terminal 100. Examples of events that occur in the mobile terminal include call signal reception, message reception, key signal input, touch input, and the like. The alarm unit 153 may output a signal for notifying the occurrence of an event in a form other than the video signal or the audio signal, for example, vibration. The video signal or the audio signal may be output through the display unit 151 or the audio output module 152 so that they may be classified as a part of the alarm unit 153.

The haptic module 154 generates various tactile effects that the user can feel. A typical example of the haptic effect generated by the haptic module 154 is vibration. The intensity and pattern of vibration generated by the haptic module 154 can be controlled. For example, different vibrations may be synthesized and output or sequentially output.

In addition to vibration, the haptic module 154 may be configured to provide a pin array that vertically moves with respect to the contact skin surface, a jetting force or suction force of air through an injection or inlet port, grazing to the skin surface, contact of an electrode, electrostatic force, and the like. Various tactile effects can be generated, such as effects by the endothermic and the reproduction of a sense of cold using the elements capable of endotherm or heat generation.

The haptic module 154 can be implemented not only to transmit the tactile effect through the direct contact but also to allow the user to feel the tactile effect through the muscular sensation of the finger or arm. The haptic module 154 may include two or more haptic modules 154 according to the configuration of the portable terminal 100.

The projector module 155 is a component for performing an image project function using the mobile terminal 100 and is similar to the image displayed on the display unit 151 in accordance with a control signal of the controller 180 Or at least partly display another image on an external screen or wall.

The memory unit 160 may store a program for processing and controlling the control unit 180 and temporarily store the input / output data (e.g., telephone directory, message, audio, For example. The memory unit 160 may also store the frequency of use of each of the data (for example, each telephone number, each message, and frequency of use for each multimedia). In addition, the memory unit 160 may store data on vibration and sound of various patterns output when the touch is input on the touch screen.

The memory 160 may be a flash memory type, a hard disk type, a multimedia card micro type, a card type memory (for example, SD or XD memory), a RAM (Random Access Memory), SRAM (Static Random Access Memory), ROM (Read Only Memory), EEPROM (Electrically Erasable Programmable Read-Only Memory), PROM A disk, and / or an optical disk. The mobile terminal 100 may operate in association with a web storage that performs a storage function of the memory 160 on the Internet.

The interface unit 170 serves as a path for communication with all external devices connected to the mobile terminal 100. The interface unit 170 receives data from an external device or supplies power to each component in the mobile terminal 100 or transmits data to the external device. For example, a wired / wireless headset port, an external charger port, a wired / wireless data port, a memory card port, a port for connecting a device having an identification module, an audio I / O port, A video input / output (I / O) port, an earphone port, and the like may be included in the interface unit 170.

The identification module is a chip for storing various information for authenticating the use right of the mobile terminal 100 and includes a user identification module (UIM), a subscriber identity module (SIM), a general user authentication module A Universal Subscriber Identity Module (USIM), and the like. Devices with identification modules (hereinafter referred to as "identification devices") can be manufactured in a smart card format. Accordingly, the identification device can be connected to the terminal 100 through the port.

The interface unit may be a passage through which power from the cradle is supplied to the mobile terminal 100 when the mobile terminal 100 is connected to an external cradle, or various command signals input from the cradle by a user may be transferred. It may be a passage that is delivered to the terminal. The various command signals or the power source input from the cradle may be operated as a signal for recognizing that the mobile terminal is correctly mounted on the cradle.

The controller 180 typically controls the overall operation of the mobile terminal. For example, voice communication, data communication, video communication, and the like. The control unit 180 may include a multimedia module 181 for multimedia playback. The multimedia module 181 may be implemented in the control unit 180 or may be implemented separately from the control unit 180. [

The controller 180 may perform a pattern recognition process for recognizing handwriting input or drawing input performed on the touch screen as characters and images, respectively.

The power supply unit 190 receives an external power source and an internal power source under the control of the controller 180 to supply power for operation of each component.

The various embodiments described herein may be embodied in a recording medium readable by a computer or similar device using, for example, software, hardware, or a combination thereof.

According to a hardware implementation, the embodiments described herein include application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), and the like. It may be implemented using at least one of processors, controllers, micro-controllers, microprocessors, and electrical units for performing other functions. The described embodiments may be implemented by the controller 180 itself.

According to the software implementation, embodiments such as the procedures and functions described herein may be implemented as separate software modules. Each of the software modules may perform one or more of the functions and operations described herein. Software code can be implemented in a software application written in a suitable programming language. The software code is stored in the memory 160 and can be executed by the control unit 180. [

Prior to explaining the present invention, a brief description will be given of the Session Initiation Protocol (SIP) for VoIP service. With the development of the Internet, services in the form of real-time multimedia such as telephone and video have been added from the existing data-oriented services. Protocols that can provide such various types of services have emerged, and SIP is the most popular among them. SIP is a protocol that supports the creation and termination of real-time multimedia sessions such as voice and video. Unlike SIP, the SIP operates independently at the transport layer. That is, the SIP may operate regardless of the type of session generated.

SIP can work with protocols such as RSVP, RTP, and SDP to transmit multimedia data. Here, RSVP is a protocol for reserving resources, RTP is a protocol for real-time data transmission, and SDP is a protocol representing characteristics of a multimedia session. Therefore, other protocols should be used together with SIP to provide complete service. Table 1 below illustrates the SIP messages described in the present invention.

Meanwhile, video telephony (VT) and VoIP services may be provided through an LTE / 3G network and may also be provided through a WiFi system. On the other hand, the current LTE / 3G network has a higher billing or wireless environment is unstable than the WiFi system. Therefore, in the present invention, even if a terminal capable of supporting video call (VT) and VoIP service through both a WiFi system and an LTE / 3G network, even when a call origination message (INVITE message), which is a SIP message, is received through the LTE / 3G network, First, it is proposed to induce retransmission by first registering (Registration) whether the service through the WiFi network is possible.

Specifically, when the calling terminal transmits the call origination message through the LTE network to which the receiving terminal is connected, the header of the SIP message may indicate that the same service is currently available in the WiFi network.

In addition, the receiving terminal receives a call origination message through the LTE network, confirms that the call is also possible through the WiFi network, and attempts to register with the WiFi network. Upon successful registration, the header may include information on the WiFi network connected to the currently connected LTE network, and the LTE network may change the path of the call origination message to the WiFi network using the WiFi network information.

Due to this feature, in the present invention, the terminal preferentially uses the WiFi network, thereby reducing the communication cost and providing a user with an opportunity of high quality and high sound quality service.

In the following embodiment, for convenience of description, it is assumed that the terminal A is connected to the WiFi network, the terminal B is connected to the LTE network.

2 and 3 are signal flow diagrams illustrating a method for receiving a VoIP call according to a first embodiment of the present invention. In particular, in FIGS. 2 and 3, it is assumed that the terminal A 100 and the terminal B 200 provide the VoIP service using the same identifier, that is, the telephone number, in both the LTE network 400 and the WiFi network 300.

In addition, FIG. 2 assumes that the registration of the terminal B 200 to the WiFi network 300 has failed, and FIG. 3 assumes that the registration of the terminal B 200 to the WiFi network 300 is successful.

First, referring to FIG. 2, in step 201, the terminal A 100 transmits an INVITE message, which is a call origination message, to the WiFi network 300, and in step 202, the WiFi network 300 transmits the INVITE message to the LTE network 400. In step 203, the LTE network 400 transmits it to the terminal B (200). Here, the INVITE message may include an identifier of the terminal B 200, that is, a destination address, that is, a phone number and an IP address. Also, in order for the terminal B 200 to transmit a response signal, the header “Contact” of the INVITE message may include an identifier of the terminal A 100, that is, a phone number and an IP address.

Here, the terminal B 200 connected to the LTE network 400 checks whether it is possible to register with the WiFi network 300 in step 204 in order to first check whether the service through the WiFi network 300 is possible. In order to transmit the "REGISTER" message to the WiFi network (300). Subsequently, in step 205, when the registration of the terminal B 200 to the WiFi network 300 fails, the WiFi network 300 transmits a “4xx Response” message, which is a failure response message, to the terminal B 200. . Or, in addition to receiving a “4xx Response” message, the terminal B 200 considers that registration to the WiFi network 300 has failed even when a preset time has elapsed after transmitting the “REGISTER” message, that is, when a “Timeout” event occurs. can do.

Accordingly, the terminal B 200 transmits the message “200 OK”, which is a response message to the INVITE message received in step 203, to the LTE network 400 to which it is connected in step 206 to perform call acceptance. The LTE network 400 forwards the “200 OK” message to the WiFi network 300 in step 207, and further, in step 208, the WiFi network 300 calls the “200 OK” message to the terminal A 100 by calling. The origination and call acceptance procedure can be completed. In this case, the “200 OK” message may include an identifier of the terminal A 100, that is, a destination phone number and an IP address. In addition, the “Contact” which is a header of the “200 OK” message may include an identifier of the terminal B 100, that is, a phone number and an IP address, for the terminal A 100 to transmit a response signal.

Next, a case in which the terminal B 200 successfully registers with the WiFi network 300 will be described with reference to FIG. 3. However, since the steps 301 to 304 in FIG. 3 are the same as the steps 201 to 204 in FIG. 2, detailed descriptions thereof will be omitted.

In step 305, since the WiFi network 300 is successfully registered with the WiFi network 300 of the terminal B 200, the WiFi network 300 transmits a “200 OK” message, which is a success response message, to the terminal B 200. In this case, the terminal B 200 transmits a message “302 Moved Temporarily” to the LTE network 400 to which it is connected in step 306 to induce a redial of the WiFi network 300.

The LTE network 400 receiving the “302 Moved Temporarily” message modifies the INVITE message in step 307 to redirect to the WiFi network 300.

Upon receiving the redirected INVITE message, the WiFi network 300 retransmits the INVITE message to the terminal B 200 in step 308, and the terminal B 200 responds to the INVITE message as shown in steps 309 and 310. OK ”to send the call. In this case, the “200 OK” message may include an identifier of the terminal A 100, that is, a destination phone number and an IP address. In addition, the “Contact” which is a header of the “200 OK” message may include an identifier of the terminal B 100, that is, a phone number and an IP address, for the terminal A 100 to transmit a response signal.

4 and 5 are signal flow diagrams illustrating a method for receiving a VoIP call according to a second embodiment of the present invention. In particular, in FIGS. 4 and 5, it is assumed that the terminal A 100 and the terminal B 200 provide VoIP services using different identifiers, that is, phone numbers, in the LTE network 400 and the WiFi network 300, respectively. . That is, the terminal A 100 uses the identifier “01011112222” corresponding to the LTE network 400 and the identifier “07055556666” corresponding to the WiFi network 300, and the terminal B 200 corresponds to the LTE network 400. The identifier “01033334444” and the identifier “07077778888” corresponding to the WiFi network 300 may be used.

In addition, FIG. 4 assumes that the registration of the terminal B 200 to the WiFi network 300 has failed, and FIG. 5 assumes that the registration of the terminal B 200 to the WiFi network 300 is successful.

First, referring to FIG. 4, in step 401, the terminal A 100 transmits an INVITE message, which is a call origination message, to the WiFi network 300, and in step 402, the WiFi network 300 transmits the INVITE message to the LTE network 400. In step 403, the LTE network 400 transmits it to the terminal B (200). As shown in FIG. 2, the INVITE message may include an identifier of the terminal B 200 that is a destination address, that is, a phone number and an IP address. Also, in order for the terminal B 200 to transmit a response signal, the header “Contact” of the INVITE message may include an identifier of the terminal A 100, that is, a phone number and an IP address. However, since the terminal A 100 transmits the INVITE message to the WiFi network 300, the identifier of the terminal A 100 included in the “Contact” may include “0705555666” which is an identifier corresponding to the WiFi network 300. have.

Next, the terminal B 200 connected to the LTE network 400 first checks whether it is possible to register with the WiFi network 300 in step 404 in order to first check whether the service through the WiFi network 300 is possible. In order to confirm, the message “REGISTER” is transmitted to the WiFi network 300. Subsequently, in step 405, when the registration of the terminal B 200 to the WiFi network 300 fails, the WiFi network 300 transmits a “4xx Response” message, which is a failure response message, to the terminal B 200. . Or, in addition to receiving a “4xx Response” message, the terminal B 200 considers that registration to the WiFi network 300 has failed even when a preset time has elapsed after transmitting the “REGISTER” message, that is, when a “Timeout” event occurs. can do.

Accordingly, the terminal B 200 transmits a message “200 OK”, which is a response message to the INVITE message received in step 403, to the LTE network 400 to which it is connected in step 406 to perform call acceptance. The LTE network 400 forwards the “200 OK” message to the WiFi network 300 in step 407, and further, in step 408, the WiFi network 300 calls the “200 OK” message to the terminal A 100 by calling. The origination and call acceptance procedure can be completed. In this case, the “200 OK” message may include an identifier of the terminal A 100, that is, a destination phone number and an IP address. In addition, the “Contact” which is a header of the “200 OK” message may include an identifier of the terminal B 100, that is, a phone number and an IP address, for the terminal A 100 to transmit a response signal. In particular, the identifier of the terminal A 100 included in the “200 OK” message is “0705555666” which is an identifier corresponding to the WiFi network 300, and the identifier of the terminal B 100 included in the header is the LTE network 400. May correspond to “01033334444”.

Next, a case in which the terminal B 200 successfully registers with the WiFi network 300 will be described with reference to FIG. 5. However, since the steps 501 to 504 in FIG. 5 are the same as the steps 401 to 404 in FIG. 4, a detailed description thereof will be omitted.

In step 505, since the WiFi network 300 is successfully registered with the WiFi network 300 of the terminal B 200, the WiFi network 300 transmits a “200 OK” message, which is a success response message, to the terminal B 200. In this case, the terminal B 200 transmits a message “302 Moved Temporarily”, which is a message for inducing re-send to the WiFi network 300, to the LTE network 400 to which it is connected in step 506.

Here, as a difference from FIG. 3, since the terminal B 200 does not use the same identifier in the WiFi network 300 and the LTE network 400, the redirection procedure is performed by the WiFi network 300 and the LTE network 400. It can be implemented by sending a new INVITE message instead of only going through the liver.

Accordingly, the LTE network 400 transmits the “302 Moved Temporarily” message to the WiFi network 300 in step 507, and the WiFi network 300 transmits the “302 Moved Temporarily” message to the terminal A 100 in step 508. Can be. The “302 Moved Temporarily” message may include an identifier of the terminal A 100, that is, a phone number and an IP address, which are destination addresses. In addition, the “Contact” header of the “302 Moved Temporarily” message may include an identifier of the terminal B 100, that is, a phone number and an IP address, for the terminal A 100 to transmit a response signal. In particular, the identifier of the terminal A 100 included in the “302 Moved Temporarily” message is “0705555666”, which is an identifier corresponding to the WiFi network 300, and the identifier of the terminal B 100 included in the header is also a WiFi network ( 300 may correspond to “07077778888”.

Upon receiving the “302 Moved Temporarily” message, the terminal A 100 retransmits the INVITE message to the terminal B 200 through the WiFi network 300 in steps 509 and 510, and the terminal B 200 receives the steps 511 and 510. As shown in 512, the call acceptance is performed by transmitting a “200 OK” message, which is a response message to the INVITE message, through the WiFi network 300.

It will be apparent to those skilled in the art that the present invention may be embodied in other specific forms without departing from the spirit of the invention. Accordingly, the above detailed description should not be construed as limiting in all aspects and should be considered as illustrative. The scope of the invention should be determined by reasonable interpretation of the appended claims, and all changes within the equivalent scope of the invention are included in the scope of the invention.

Claims (14)

A method of receiving a Voice over Internet Protocol (VoIP) call of a terminal in a wireless communication system,
Receiving a call origination message via a first communication network;
Transmitting a registration attempt message to a second communication network;
When the registration acceptance message is received from the second communication network, transmitting a redirect request signal of the call origination message to the first communication network;
Receiving the call origination message again from the second communication network; And
And transmitting a call accept message to the second communication network.
How to receive VoIP call. The method of claim 1,
And transmitting a call acceptance message to the first communication network when a predetermined time elapses after receiving a registration rejection message from the second communication network or transmitting the registration attempt message.
How to receive VoIP call. The method of claim 2,
The terminal,
And a first identifier corresponding to the first communication network and a second identifier corresponding to the second communication network.
How to receive VoIP call. The method of claim 3, wherein
The header of the call accept message transmitted to the second communication network,
And a second identifier corresponding to the second communication network.
How to receive VoIP call. The method of claim 3, wherein
The header of the call accept message transmitted to the first communication network,
And a first identifier corresponding to the first communication network.
How to receive VoIP call. The method of claim 1,
The first communication network,
Receiving the redirect request signal, forwarding the call origination message to the second communication network;
How to receive VoIP call. The method of claim 1,
The first communication network is a Long Term Evolution (LTE) communication network,
The second communication network, characterized in that the WiFi (Wireless Fidelity) communication network,
How to receive VoIP call. A terminal apparatus in a wireless communication system,
One or more wireless communication modules for transmitting and receiving signals with the first and second communication networks; And
A processor for processing signals transmitted and received through the wireless communication module,
The processor comprising:
Receiving a call origination message through the first communication network, transmitting a registration attempt message to the second communication network, and receiving a registration acceptance message from the second communication network, redirecting the call origination message to the first communication network. Control the wireless communication module to transmit a request signal, to receive the call origination message again from the second communication network, and to send a call accept message to the second communication network;
Terminal device. The method of claim 8,
The processor comprising:
The wireless communication module is controlled to transmit a call acceptance message to the first communication network when a predetermined time elapses after receiving a registration rejection message from the second communication network or transmitting the registration attempt message.
Terminal device. The method of claim 9,
The terminal apparatus comprises:
And a first identifier corresponding to the first communication network and a second identifier corresponding to the second communication network.
Terminal device. 11. The method of claim 10,
The header of the call accept message transmitted to the second communication network,
And a second identifier corresponding to the second communication network.
Terminal device. 11. The method of claim 10,
The header of the call accept message transmitted to the first communication network,
And a first identifier corresponding to the first communication network.
Terminal device. The method of claim 8,
The first communication network,
Receiving the redirect request signal, forwarding the call origination message to the second communication network;
Terminal device. The method of claim 8,
The first communication network is a Long Term Evolution (LTE) communication network,
The second communication network, characterized in that the WiFi (Wireless Fidelity) communication network,
Terminal device.

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