KR100923642B1 - Method of video phone call using a bridge - Google Patents

Abstract

The present invention relates to a videophone, and more particularly, to a videophone call method using a bridge for processing video and audio signals by connecting two videophones to a single videophone line by a bridge. According to the present invention, two video telephones are connected in one video call line using a bridge in a VOIP network, so that a video telephone can be used simultaneously in a place away from home or office, and the video call line can be efficiently used. Video phone call using bridge.

Video signal, audio signal, bridge, video phone.

Description

Method of video phone call using a bridge {Method of video phone call using a bridge}

The present invention relates to a videophone, and more particularly, to a videophone call method using a bridge for processing video and audio signals by connecting two videophones to a single videophone line by a bridge.

In general, voice over internet protocol (VoIP) is a core technology of internet telephony, and provides a voice service provided through a PSTN network to various services using the Internet protocol (IP).

Since VoIP technology must be interworked not only in the Internet but also in private IP based networks, public switched telephone networks (PSTNs), or their complex networks, standardization of technologies and protocols is important, and importantly, H.323-based technologies developed by ITU-T. SIP-based technologies developed by IETF and IETF, and MEGACO (Media Gateway Control) based technologies jointly developed by ITU-T and IETF to lead the next-generation VoIP gateway market. H.323 is a standard for constituent functional elements, functions, protocols and procedures for multimedia communication services used in video conferencing systems. Components include an end point, a gateway, a gatekeeper, a multipoint control unit (MCU), a multi-point processor (MP), a multipoint controller (MC), and the like. Session Initiation Protocol (SIP) is widely used as a call signaling protocol for Internet application services in various fields. MEGACO / H.248 standardized as a protocol to control the media gateway, which is a media-to-media converter required when providing multimedia services by connecting various networks and the Internet, including telephone networks.

Hereinafter, a video call using a conventional video telephone will be described with reference to the drawings.

1 is a schematic configuration diagram of processing a video call using a conventional VOIP service.

A VOIP server 20 for processing a video call service through an internet network and two VOIP video phones 22 and 24 of a sender and a receiver are shown.

The VOIP video phone 22 registers as an account assigned by the VOIP server 20 and makes a call through the VOIP video phone 24 of the other party. At this time, the VOIP video phones 22 and 24 connect one terminal to one video call line provided by the VOIP server 20 to process video and voice calls.

In the conventional VOIP service, the call between the VOIP video phone 22 processes voice and video calls through the VOIP server 20, and only one VOIP video phone 22 is connected to one video call line to process the call. If you want to use two video phones together, there was a problem that requires two lines.

The present invention solves the above-described problems, the present invention is to connect two video phones in a video call line using a bridge in a VOIP network at the same time using a video phone at a time away from each home or office An object of the present invention is to provide a video telephone call method using a bridge that can efficiently and efficiently use a video call line.

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The method of the present invention for achieving the above object comprises the steps of receiving a call connection request sent from the video telephone of the caller in the video telephone 1, the video call 2 connected to the video telephone 1 and the bridge to share the account the call connection request And transmitting both the video phone 1 and the video phone 2 to the caller's video phone, in which the video signal of the video phone 1 or the video signal of the video phone 2 is preset. Characterized in that it comprises the step of transmitting.
In addition, the video telephone 1 is characterized in that for receiving a voice signal and a video signal of the video telephone 2 and transmits to the video telephone of the caller.

In addition, if both the video telephone 1 and the video telephone 2 of the present invention accept the call connection, the voice signal includes transmitting both the video telephone 1 and the video telephone 2 simultaneously to the caller's video telephone.

In addition, transmitting one video signal of the present invention to the caller's video phone, characterized in that only the video signal of the video phone that first received the call in the video phone 1 and the video phone 2 to the caller's video phone. do.

In addition, the transmission of one video signal of the present invention to the video telephone of the caller, the first video signal from the video telephone 1 and the video telephone 2 receives the first call from the video telephone 1 when the video signal is sent to the hook-off message to the video telephone 2; A message indicating that there is a priority is transmitted together and the video signal is transmitted to the caller's video telephone.

In addition, the message indicating that there is a video signal transmission priority when transmitting the hook-off message of the present invention, characterized in that the first message set whether or not to transmit the video signal from the video telephone 1 is connected.

In addition, the transmission of one video signal of the present invention to the caller's video telephone includes the steps of receiving a call first at the video telephone 1 and later receiving the handset from the video telephone 2 and transmitting a hook-off message to the video telephone 1; The video phone 1 transmits a message indicating that the video signal transmission priority has priority when the ACK message is transmitted in response to the video phone 2 and transmits the video signal to the video phone of the caller.

The present invention has the advantage that only one video phone can be used for one account in a VOIP network, so that two video phones can be used at the same time at a place away from home or office.

In addition, the present invention has the effect of reducing the line and the cost because it is used by connecting two video phones to one video call line.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

It should be noted that in the following description, only parts necessary for understanding the operation according to the present invention will be described, and descriptions of other parts will be omitted.

For convenience of description, the same reference numerals are assigned to components that perform the same functions and roles even in other embodiments (drawings).

2 is a schematic configuration diagram of processing a video call using the VOIP service of the present invention.

FIG. 2 shows the video telephones 1, 2 (34, 36) of the receivers connected using the VOIP server 30, the video telephone 32 of the caller, and the bridge 38. As shown in FIG.

The video phone transmits and receives a voice signal and a video signal using a VOIP service, and the bridge 38 processes the video signal and the audio signal control signal between two video phones.

The VOIP server 30 manages each terminal in the VOIP network and controls the VOIP call connection between the terminals.

The video phone 1 34 provides the video phone 2 36 with the voice signal and the video signal of the caller transmitted from the VOIP server 30 to the video phone 2 36 bridged during the video call using the VOIP service. In addition, the VOIP packets transmitted from the video phone 2 (36) are transmitted to the video phone 1 (34) through the bridge and again to the other party through the VOIP server (30).

Video phones 1 and 2 (34, 36) send and receive separate control packets for processing video and voice calls.

The transmission of video signals during video calls using two video phones 1, 2 (34, 36) connected by a bridge 38 is performed by one video phone 1, 2 on two video phones 1, 2 (34, 36). Only 34 and 36 are selected to transmit video signals, and audio signals can be simultaneously transmitted from two video phones 1 and 2 (34 and 36).

The reception of the video signal is provided to the video telephone 1 (34) through the VOIP server 30, and provided to the video telephone 2 (36) via the bridge 38 from the video telephone 1 (34). Two video phones 1, 2 (34, 36) receive simultaneously.

Figure 3 is a flow chart of the two video telephones connected by the bridge of the present invention when the call is received only when the video telephone 1 receives the call.

In step S202, when the caller's video phone 32 requests a call for a call, an INVITE message is transmitted to the video phone 1 34 through the VOIP server 30.

In step S204 ~ S206 video phone 1 (34) transmits the 100 Trying and 180 Ringing messages to the caller's video phone 32 through the VOIP server 30 in response to the INVITE message.

In operation S208, when the user picks up the receiver at the video telephone 1 34 connected to the bridge 38, the 200 OK message is transmitted to the caller's video telephone 32 through the VOIP server 30, and the video telephone 1 34 is The video phone 2 36 sends a Hook Off message, and the video phone 2 36 sends an ACK message to the video phone 1 34 in response.

In step S212, the caller's video phone 32 transmits an ACK message to the video phone 1 (34) through the VOIP server 30 in response to the 200 OK message.

In step S214, video and voice calls are made between the caller's video phone 32 and the receiver's video phone 1 34 connected by a bridge using a real-time transport protocol (RTP).

The real-time transport protocol (RTP) is located at a higher layer of the user datagram protocol (UDP) and is transmitted as a payload of an RTP packet whenever an encoded voice packet is transmitted. The RTP packet has an RTP header that provides information such as the speech coding scheme used, the sequence number, the timestamp for the time the speech packet was sampled, and identification information about the origin of the speech packet.

RTP is a paired protocol with RTCP (RTP Control Protocol), and RTCP is a signaling protocol that does not transmit encoded voice packets, but instead contains many messages sent between session users.

After completing the video call and the voice call with each other and hooking up the handset at the receiver's video phone 1 (34) in step S216, the video phone 1 (34) sends the BYE message through the VOIP server 30 to the caller's video. The phone 32 transmits a hook on message to the video phone 2 36 connected as a bridge in step S218.

The caller's video phone 32 sends a 200 OK message to the video phone 1 34 via the VOIP server 30 in response to the BYE message to terminate the call.

In the two video telephones described with reference to FIG. 3, a call setup for calling and ending upon receiving a call only from the video telephone 1 applied SIP (Session Initiation Protocol). The following description also applies to SIP.

SIP is more flexible and simpler than H.323, and is easy to implement. SIP is a signaling protocol and does not transmit voice or video packets themselves. It uses the above-mentioned RTP to transmit video and voice packet data.

Figure 4 is a flow chart of the call is terminated when the call is received only from the video phone 2 in the two video phones connected by the bridge of the present invention.

2, the video telephone 2 36 is connected to the video telephone 1 34 through the bridge 38 to make a call.

The video signal and the audio signal of the video telephone 2 (36) are transmitted to the caller's video telephone through the video telephone 1 (34).

When the caller's video phone 32 requests a call for a call in step S302, the INVITE message is transmitted to the video phone 1 34 through the VOIP server 30, and the video phone 1 is again sent from the video phone 1 34. Transmit to 2 (36).

The video phone 2 (36) receiving the INVITE message in steps S304 to S306 transmits 100 Trying and 180 Ringing messages to the video phone 1 (34) in response, and the video phone 1 (34) via the VOIP server 30. 100 Trying and 180 Ringing messages are sent to the caller's video phone (32).

In operation S308, when the handset is received by the video telephone 2 36 connected by the bridge 38, the video telephone 2 36 transmits a hook off message to the video telephone 1 34, and the video telephone 1 34 is transmitted. Sends an ACK message to video phone 2 36 in response.

In step S310 ~ S312 video phone 1 (34) transmits a 200 OK message to the caller's video phone 32 through the VOIP server 30, the video phone 32 of the caller sends an ACK message in response to the video phone 1 Transmit to video phone 2 (36) via (34).

In step S314, the video phone 32 of the caller and the video phone 2 36 of the receiver connected by the bridge are connected to each other using a real-time transport protocol (RTP) through the VOIP server 30. Make a call.

When the receiver finishes the video call and the voice call and proceeds to step S316 to hang up the call on the video phone 2 (36) of the receiver, a hook on message is sent to the video phone 1 (34) and in response, the video phone 1 ( 34) and transmits an ACK message to the video telephone 2 (36).

In step S318, the video phone 1 34 transmits a BYE message indicating the end of the call to the caller's video phone 32 through the VOIP server 30, and in step S320, the caller's video phone 32 sends the BYE message. In response to the message, the 200 OK message is transmitted to the video phone 1 34 and the video phone 2 36 through the VOIP server 30, thereby ending.

FIG. 5 is a flowchart illustrating an operation in the case where two video telephones connected by the bridge of the present invention are first called in the video telephone 1 and later connected to the video telephone 2. FIG.

In step S402, when the caller's video phone 32 requests a call for a call, the INVITE message is transmitted to the video phone 1 34 through the VOIP server 30, and the video phone 1 is again sent from the video phone 1 34. Transmit to 2 (36).

Receiving the INVITE message in step S404 ~ S406 video phone 1 (34) transmits the 100 Trying and 180 Ringing messages to the caller's video phone (32).

When the user picks up the handset of the video telephone 1 (34) at steps S408 to S410, a 200 OK message is transmitted to the caller's video telephone 32 via the VOIP server 30, and the video telephone 1 (32) to the video telephone 2 ( Send a Hook Off message to video phone 2, and video phone 2 36 sends an ACK message to video phone 1 34 in response.

In step S412, when the caller's video telephone 32 receives the 200 OK message, it transmits an ACK message to the video telephone 1 34 in response to the VOIP server 30.

In step S414, the video telephone 32 of the caller and the video telephone 1 34 of the receiver make a video call and a voice call to each other using a real-time transport protocol (RTP) via the VOIP server 30.

If the receiver attempts to make a call by picking up the receiver's video phone 2 (36) during the video call and voice call with the caller, proceeding to step S416, a hook off message is transmitted to the video phone 1 (34) and the video in response. The telephone 1 34 sends an ACK message to the video telephone 2 36.

In operation S418, when the video telephone 2 36 receives an ACK message, the video telephone 2 36 transmits an audio and video signal to the video telephone 1 34, and the video telephone 1 34 receives only the audio signal from the received audio and video signal. 30 is transmitted to the caller's video phone (32).

That is, the video signal can be transmitted only from the first video phone 1 34 connected, and the video signal of the video phone 2 36 is not transmitted but only the audio signal.

When the voice and video signals sent from the caller's video telephone 32 are transmitted to the video telephone 1 34 in step S420, the audio and video signals are also provided to the video telephone 2 36 through the bridge 38.

Therefore, the two video phones 1 and 2 (34, 36) connected to the bridge can separately view the video signal of the other party, and the audio signal can be simultaneously transmitted and received.

As described above, the video signal can be transmitted only from the first video phone 1 (34) to be connected first, and the video signal of the video phone 2 (36) is not transmitted but only the audio signal is transmitted. At 34 and 36, the video signal of the other party can be seen and the audio signal can be simultaneously transmitted and received.

6 is a flowchart illustrating an operation in the case where a video telephone 1 of the present invention is first called and later connected to the video telephone 2. FIG.

In steps S502 to S514, a call is first connected between the video caller 32 of the caller and the video phone 1 34 connected by a bridge to process a video call and a voice call.

Step S516 is a hook-off message from the video phone 2 36 to the video phone 1 34 when the caller lifts the handset from the video phone 2 36 during the video call between the caller's video phone 32 and the video phone 1 34. The video signal is transmitted from the video phone 1 (34) to the video phone 2 (36) together with the response ACK message to the video phone 2 (36).

In step S518, a video call is made between the caller's video phone 32 and the video phone 1 34, and the video signal of the video phone 2 36 is not transmitted. The audio signal and the video signal of the video telephone 1 34 are transmitted to the caller's video telephone 32 using the real-time transport protocol (RTP) via the VOIP server 30.

6 shows a video call priority message along with a video call priority message in response ACK message in video phone 1 34 when a call is connected in video phone 1 34 and later in video phone 2 36. In this case, the video signal is transmitted only from the video phone 1 34 to be controlled.

FIG. 7 is a flowchart illustrating a case where the first telephone call is made in the video telephone 1 of the present invention and the video telephone 1 is terminated first after the first telephone call is connected to the video telephone 2.

In step S602, a call is first connected between the caller's video phone 32 and the video phone 1 34 connected by a bridge to make a video call and a voice call.

In addition, the video telephone 2 picks up the handset and makes video and audio calls through the video telephone 1 (34).

In this case, the video signal is transmitted to the caller only from the video phone 1 34, and the video phone 2 36 can transmit only the audio signal, and both receive the video signal and the audio signal.

In step S604, when the call is ended and the telephone is disconnected from the video telephone 1 (34), the hook-on message is transmitted to the video telephone 1 (34) indicating that the handset has been put down. In response, video phone 2 36 sends an ACK message.

After transmitting the ACK message from the video phone 2 36 in step S606, the video signal and the audio signal are transmitted from the video phone 2 36 using the real-time transport protocol (RTP) via the VOIP server 30. Is sent to the video phone 32 to make a video call.

When the video call 2 ends the video call and the voice call and hangs up, the flow proceeds to step S608 where a hook on message is sent to the video call 1 34 and in response, the video call 1 34 receives the ACK. The message is sent to the video telephone 2 (36).

In step S610, the video phone 1 34 transmits a BYE message indicating the end of the call to the caller's video phone 32 through the VOIP server 30, and in step S612, the caller's video phone 32 responds to the BYE message. In response, the 200 OK message is transmitted to the video phones 1 and 2 (34, 36) through the VOIP server 30.

8 is a flowchart illustrating an operation in which the first telephone call is made in the videophone 1 of the present invention and the videophone 2 is terminated first after being connected to the videophone 2 later.

In step S702, a call is first connected between the caller's video phone 32 and the bridged video phone 1 34 to process a video call and a voice call.

In addition, the video telephone 2 picks up the handset and makes video and audio calls through the video telephone 1 (34).

In this case, the video signal can be transmitted to the caller only in the video phone 1 34, and the video phone 2 36 can transmit only the audio signal, and both receive the video signal and the audio signal of the caller.

In step S704, when the call is ended and the telephone is disconnected from the video telephone 2 (36), the video telephone 1 (34) transmits a Hook On message indicating that the handset is dropped, and in response, the video telephone 1 ( Send an ACK message to video phone 2 (36).

After transmitting the ACK message from the video phone 1 34 in step S706, the video signal and the audio signal are transmitted to the caller using the real-time transport protocol (RTP) via the VOIP server 30 only on the video phone 1 34. Is sent to the video phone 32 to make a video call.

When the video telephone 1 (34) ends the video call and the voice call and hangs up, the process proceeds to step S708, and the video telephone 1 (34) sends a BYE message indicating the end of the call through the VOIP server 30 to the caller's video telephone 32 In step S710, the video phone 1 34 transmits a hook on message to the video phone 2 36 from the video phone 1, and the video phone 2 36 transmits an ACK message in response.

In step S712, the video telephone 32 of the caller sends a 200 OK message to the video telephone 1 34 through the VOIP server 30 in response to the BYE message.

FIG. 9 is a flowchart illustrating an operation in which a video telephone 1 of the present invention calls first and is later connected to a video telephone 2, and then the video telephone 2 ends the call first.

First, in step S802, as described above, the video phone 2 36 and the caller's video phone 32 are processed for the call, and in step S804 video call 1 through the video phone 1 (34).

In step S806, the telephone receiver of the video telephone 1 (34) is lifted during the call, and the voice signal is transmitted to the caller's video telephone 32 by using the real-time transport protocol (RTP) via the VOIP server 30. The video signal of the video telephone 1 34 is discarded without being transmitted.

In step S808, when the handset of the video telephone 1 (34) is lifted, a hook off message is transmitted to the video telephone 2 (36), and in response, the video telephone 2 (36) sends an ACK message to the video telephone 1 (34). Send.

In operation S810, the video phone 1 34 transmits only the audio signal to the caller's video phone 32, and the video phone 2 36 transmits both the video signal and the audio signal to make a call.

In the case of Fig. 9, the first video telephone 2 (36) which connects a call transmits both a video signal and an audio signal to the other video telephone 32, and the video telephone 1 (34) discards the video signal without transmitting it. .

10 is a flowchart illustrating the operation when the first video phone 2 is received first and the video phone 1 is connected later.

First, in step S902 to S906, as described above, the video phone 1, 2 (34, 36) and the caller's video phone 32 for setting the call for processing, and in step S908 video phone 2 (36) the user first When the receiver hears the handset, the video signal priority sends a Hook Off message to video phone 1 34, including a message to video phone 2 36, which provides an ACK message in response. do.

In step S910, the video telephone 1 34 transmits a 200 OK message to the caller's video telephone 32 through the VOIP server 30, and in step S912, the caller's video telephone 32 responds to the 200 OK message. The ACK message is transmitted to the video telephones 1 and 2 (34 and 36) through the VOIP server 30.

In operation S914, the video call is made between the caller's video phone 32 and the video phone 2 36.

In step S916, the handset of the video telephone 1 (34) is picked up to make a call by transmitting a voice signal to the caller's video telephone (32) using a real-time transport protocol (RTP) via the VOIP server 30. The video signal of the telephone 1 34 is discarded without being transmitted.

In operation S918, the video phone 1 34 transmits a hook off message to the video phone 2 36, and transmits an ACK message to the video phone 1 34 from the video phone 2 36. FIG.

In step S920, the first video phone 2 (36) which connects the call transmits both the video signal and the audio signal to the video phone 32 of the other party. In the video phone 1 (34), the video signal is discarded without being transmitted. Only send a signal and talk.

FIG. 11 is a flowchart illustrating an operation when the video phone 2 is first received in the present invention and the video phone 1 is disconnected after the video phone 1 is connected.

First, as described above in step S1002, the video phone 2 36 receives the call and is given priority to the video call, and then the video phone 1 34 is set up for the call between the caller's video phone 32. Process the video call.

In step S1004, when the video telephone 1 34 ends the call and hangs up, the video telephone 2 36 transmits a hook-on message, and the video telephone 2 36 transmits an ACK message in response.

In step S1006, the video phone 2 (36) conducts a video call between the caller's video phone (32) and the video signal and the audio signal through the VOIP server 30 by using a real-time transport protocol (RTP). Transmit and receive via phone 1 (34).

In step S1008, when the video phone 2 (36) completes the video call and hangs up, the video phone 1 (34) transmits a hook-on message, and the video phone 1 (34) transmits an ACK message in response.

In operation S1010, the video telephone 1 34 processes the call termination after transmitting the ACK message and transmits the BYE message to the caller's video telephone 32 via the VOIP server 30.

In step S1012, the caller's video phone 32 transmits a 200 OK message to the video phone 2 36 through the video phone 1 34 via the VOIP server 30 in response to the BYE, thereby completing the call.

FIG. 12 is a flowchart illustrating operations when the video telephone 2 of the present invention is first received and later disconnected from the video telephone 2 after the video telephone 1 is connected.

First, as described above in step S1102, the video phone 2 36 receives the call and is given priority to the video call. Then, the video phone 1 34 sets the setting for the call between the caller's video phone 32. Process the video call.

In step S1104, when the video telephone 2 36 ends the call and hangs up, the video telephone 1 34 transmits a hook on message to the video telephone 1 34, and the video telephone 1 34 transmits an ACK message in response.

In operation S1106, the video telephone 1 34 performs a video call between the caller's video telephone 32 using a real-time transport protocol (RTP) via the VOIP server 30, and the video signal and the audio signal are video. Transmitted and received at phone 1 (34).

In step S1108, when the video telephone 1 34 ends the video call and hangs up, the BYE message is transmitted to the caller's video telephone 32 via the VOIP server 30.

In addition, the process proceeds to step S1110 and the video telephone 1 (34) to the video phone 2 (36) transmits a hook-on message, the video telephone 2 (36) transmits an ACK message in response.

Finally, in step S1112, the video telephone 1 34 processes the call termination after receiving the ACK message and transmits a 200 OK message to the caller's video telephone 32 via the VOIP server 30 to terminate the call.

So far, the configuration and operation of the embodiment of the present invention have been described. The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined not only by the claims but also by the equivalents of the claims.

1 is a schematic configuration diagram of processing a video call using a conventional VOIP service.

2 is a schematic configuration diagram of processing a video call using the VOIP service of the present invention.

Figure 3 is a flow chart of the two video telephones connected by the bridge of the present invention when the call is received only when the video telephone 1 receives the call.

Figure 4 is a flow chart of the call is terminated when the call is received only from the video phone 2 in the two video phones connected by the bridge of the present invention.

FIG. 5 is a flowchart illustrating an operation in the case where two video telephones connected by the bridge of the present invention are first called in the video telephone 1 and later connected to the video telephone 2. FIG.

6 is a flowchart illustrating an operation in the case where a video telephone 1 of the present invention is first called and later connected to the video telephone 2. FIG.

FIG. 7 is a flowchart illustrating a case where the first telephone call is made in the video telephone 1 of the present invention and the video telephone 1 is terminated first after the first telephone call is connected to the video telephone 2.

8 is a flowchart illustrating an operation in which the first telephone call is made in the videophone 1 of the present invention and the videophone 2 is terminated first after being connected to the videophone 2 later.

FIG. 9 is a flowchart illustrating an operation in which a video telephone 1 of the present invention calls first and is later connected to a video telephone 2, and then the video telephone 2 ends the call first.

10 is a flowchart illustrating the operation when the first video phone 2 is received first and the video phone 1 is connected later.

FIG. 11 is a flowchart illustrating an operation when the video phone 2 is first received in the present invention and the video phone 1 is disconnected after the video phone 1 is connected.

FIG. 12 is a flowchart illustrating operations when the video telephone 2 of the present invention is first received and later disconnected from the video telephone 2 after the video telephone 1 is connected.

<Description of Major Symbols in Drawing>

30: VOIP Server

32: caller's video phone

34, 36: Receiver's video phone 1, 2

38 bridge

Claims (9)

Receiving, at videophone 1, a call connection request sent by the caller's videophone; Forwarding the call connection request to video phone 2 that is bridged with the video phone 1 to share an account; And When both the video telephone 1 and the video telephone 2 are connected to a call, transmitting only one video signal preset from the video signal of the video telephone 1 or the video signal of the video telephone 2 to the caller's video telephone. Videophone call method using a bridge, characterized in that it comprises a. The method of claim 1, The video telephone 1, The video telephone call method using the bridge, characterized in that for receiving a voice signal, the video signal of the video telephone 2 and transmits to the video telephone of the caller. The method of claim 1, If both video phone 1 and video phone 2 accept the call connection, And transmitting the audio signal to both the video telephone 1 and the video telephone 2 simultaneously to the video telephone of the caller. The method of claim 1, Transmitting the one video signal to the caller's video telephone, The video telephone call method using the bridge, characterized in that for providing only the video signal of the video telephone that first received the call in the video telephone 1 and the video telephone 2. The method of claim 1, Transmitting the one video signal to the caller's video telephone, The video phone 1 and the video phone 2 first receive a call from the first video phone and transmit a message indicating that there is a video signal priority when sending a hookoff message to the second video phone, and transmit the video signal to the caller. Video phone call using the bridge, characterized in that for transmitting to the video telephone. The method of claim 5, When the hook-off message is transmitted, a message indicating that there is a video signal transmission priority, The video telephone call method using a bridge, characterized in that the first message is set whether or not to transmit a video signal from the video telephone 1 connected. The method of claim 1, Transmitting the one video signal to the caller's video telephone, Receiving a call first at the videophone 1 and later picking up the handset at the videophone 2 and sending a hook-off message to the videophone 1; And The video phone call method using the bridge, characterized in that for transmitting the video signal priority to the video phone 2 to the video telephone 2 when the ACK message is sent in response to the video phone 1; . The method of claim 7, wherein When the ACK message is transmitted, a message indicating that there is a video signal priority is The video telephone call method using the bridge, characterized in that the first message is set whether or not to transmit the video signal from the video telephone 1 is connected. The method of claim 1, When both the video telephone 1 and the video telephone 2 call and one video telephone terminates the call, another video telephone connected to the video telephone transmits a video signal to the video telephone of the caller. Way.

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