JP4941146B2 - Communication system and communication method - Google Patents

Description

  The present invention relates to a communication system and a communication method, and more particularly to a communication system and a communication method for performing image communication and voice communication between a thin client telephone system including a client telephone and a server.

  With the rapid development of IP technology in recent years, a thin client type telephone system comprising a server and a plurality of client type telephones under its control is used. In this thin client type telephone system, image communication and voice communication between a plurality of client type telephones are performed via a server having the client type telephones under control.

  Call connection information with another telephone requested by the client telephone is transmitted to a server having the client telephone under its control. Then, the call connection signal transmitted to the server is transmitted to another server having another telephone under its control, and the call connection is performed between the servers. Both servers establish both video communication and voice communication links at the same time, and provide videophone functions to subordinate client phones.

  The server processes image communication and voice communication simultaneously. The image signal received by the server is converted into a screen signal to be displayed on the display unit of the client type telephone by the image processing unit of the server, and transmitted to each client type telephone. Conversely, the server converts an image signal captured by the camera of the subordinate telephone into an image signal and transmits the image signal to another server via the network.

  The audio signal received by the server is transmitted to the client telephone set under the server. Conversely, the server transmits the audio signal from the subordinate telephone to another server via the network.

Thus, a videophone is realized by performing image communication and voice communication via a server (see, for example, Patent Document 1).
Japanese Patent Laying-Open No. 2005-6240

  However, as described above, a thin client type telephone in which a plurality of client type telephones are connected under the server, and the server performs proxy processing for communication processing of individual client type telephones and omits communication processing functions of individual client type telephones. In the system, although the system can be simplified, the server is overloaded because it simultaneously processes image communication and voice communication of a plurality of client type telephones. When the server is overloaded, there is a problem that the processing of the image communication and the voice communication is delayed, and the sound is interrupted.

  The present invention has been made in view of the problems of the above-described technology, and is a communication system capable of preventing the sound from being interrupted while suppressing the server from being overloaded. And providing a communication method.

In order to achieve the above object, the present invention provides:
A communication system for performing image communication and voice communication between a thin client type telephone system comprising a client type telephone and a server having the client type telephone under control,
Control means for establishing a link between the thin client telephone systems;
The control means includes
A database in which the telephone number and connection destination information of the client type telephone and the connection destination information of a server under the client type telephone are registered as a set;
Referring to the database, for one call, for the image communication, the server has a client phone that is a source of image information and a client phone that is a destination of the image information. A link is established between these two servers by using connection destination information of each server, and for the voice communication, a client phone that is a voice information transmission source and a client phone that is a voice information transmission destination Link establishing means for establishing a link between these two client-type telephones using respective telephone numbers;
For one call, the image communication is conducted through a pre-Symbol server Te between the client phone using the established link, the voice communication, the client by using the established link Between the telephones without using the server.

  As described above, in the present invention, for one call, image communication is performed via a server, but for voice communication, voice communication is performed between individual client-type telephones. Therefore, in the server, the voice communication processing of the subordinate client type telephone is not necessary, the load on the server is reduced, and the overload state is suppressed. Further, even when the server is overloaded, it is possible to prevent the voice from being interrupted by performing the voice processing in real time without affecting the voice communication process.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a diagram showing an embodiment of a communication system of the present invention.

  In this embodiment, as shown in FIG. 1, a thin client type telephone system 56, a thin client type telephone system 57, and a call control device 51 as a control means are connected via a LAN 63.

  The thin client type telephone system 56 is configured by connecting two client type telephones 36 and 37 and a server 31 having the telephones 36 and 37 under the control of the LAN 61. The server 31 is connected to the LAN 63. Note that the number of telephones 36 and 37 that the server 31 has is not limited to two as illustrated.

  Similarly, the thin client type telephone system 57 includes two client type telephones 46 and 47 and a server 41 having the telephones 46 and 47 connected thereto via a LAN 62. The server 41 is connected to the LAN 63. The number of telephones 46 and 47 that the server 41 has is not limited to two as shown in the figure.

  2 is a diagram showing a configuration example of the telephones 36, 37, 46, and 47 shown in FIG. 1, in which (a) is a schematic overview, and (b) is a configuration of the panel surface 5 shown in (a). FIG. FIG. 3 is a diagram mainly showing a hardware configuration of the telephone set shown in FIG.

  As shown in FIG. 2A, the telephones 36, 37, 46, and 47 in the present embodiment are wired to the main body part 4 and a main body part 4 formed of a desk phone-shaped casing placed on the desk. It is comprised from the receiver part 1 connected by radio | wireless. The main unit 4 has a telephone operation unit 5a on the board surface 5 at the top of the casing, and a computer unit 3 connected to the receiver unit 1 and the telephone operation unit 5a inside the casing.

  The receiver unit 1 is configured to be able to be placed in a recess provided in the main body unit 4, and is placed in this recess when not talking. In this recess, a mechanical hook switch 2 for detecting an off-hook state in which the receiver unit 1 is picked up and an on-hook state in which the receiver unit 1 is placed is provided. On-hook / off-hook is mechanically detected by a mechanical contact. This off-hook / on-hook signal is output to the computer unit 3 via an interface such as a USB. In addition, the computer unit 3 has a videophone device installed with an IP softphone for performing communication using the Internet protocol and having a videophone function.

  Further, as shown in FIG. 2B, the panel surface 5 of the main body unit 4 includes a display unit 11, a line button unit 12, a key unit 13, a function button unit 14, a digital button unit 15, and a camera. A part 16, a speaker part 17, a microphone part 18, and a pointing device (mouse) part 19 are provided.

  The display unit 11 is a liquid crystal display or a liquid crystal touch panel. When the display unit 11 is a liquid crystal touch panel, the pointing device unit 19 can be omitted. The display unit 11 is connected to the LAN interface 23. The screen signals for the display unit 11 generated from the image signals by the servers 31 and 41 are input from the LAN interface 23 via the LANs 61 and 62 and supplied to the display unit 11. The display unit 11 displays screen information.

  The line button unit 12 includes a plurality of buttons, and is connected to the computer unit 3 through an interface such as USB, and performs input / output with respect to the external interface of the softphone. Specifically, a line button lighting / extinguishing signal or the like is received from the softphone as an input, and a line button pressing signal is passed to the softphone as an output.

  The key unit 13 has a mechanical push button 13a for performing a dial operation, and detects on / off of the push button by a mechanical contact. By depressing the push button 13a, the communication partner can be mechanically specified. Of the standard keyboard keys of the computer, such as direction keys and return keys, only keys that are mainly used for telephone operations using a softphone are arranged. Although the arrangement of the telephone push button and the numeric keypad of the computer is different from each other, the arrangement of the telephone push button is used. In this manner, by arranging the push buttons as the main keys while narrowing down to the necessary keys, it is possible to obtain an appearance, size, and operability close to those of a telephone rather than a computer. When a standard keyboard is to be used, a USB keyboard is connected to the USB interface of the computer unit 3 and used.

  The function button unit 14 includes a reset button 14a, a hold button 14b, a transfer button 14c, and a hook button 14d. It is connected to the computer unit 3 through an interface such as USB, and inputs / outputs to / from the external interface of the softphone, and passes a function button press signal as an output to the softphone. The reset button 14a forcibly returns the device to a predetermined state when it is desired to make a call regardless of the state of the device.

  The Digiless button unit 15 is connected to the computer unit 3 through an interface such as a USB, and inputs / outputs to / from the external interface (API) of the softphone, and outputs a digital button press signal to the softphone. hand over. The purpose is to allow the softphone to display the function of the Desires button on the screen of the display unit 11 adjacent to the Desires button, and to change the display depending on the state of the softphone. This is to enable the softphone to interpret the meaning of the digital button press signal according to the state.

  The USB interface 25 transmits / receives digital signals to / from a USB interface such as another terminal via a connection line.

  The telephones 36, 37, 46, and 47 each have a videophone function. The camera unit 16 is connected to the computer unit 3 through an interface such as a USB, and is used when a softphone or application software cooperates with a camera for the purpose of a videophone / videoconferencing function.

  The speaker unit 17 is connected to the audio output of the computer unit 3, and the microphone unit 18 is connected to the audio input of the computer unit 3.

  The telephones 36, 37, 46, and 47 include an RGB analog image signal interface and a DVI digital image signal interface.

  The RGB analog image signal interface includes an RGB analog image signal input interface 26 and an RGB analog image signal output interface 27. The RGB analog image signal input interface 26 is an interface for inputting three analog image signals of RGB, and the RGB analog image signal output interface 27 is an interface for outputting three analog image signals of RGB. -A SUB connector is used as an interface.

  The DVI digital image signal interface includes a DVI digital image signal input interface 28 and a DVI digital image signal output interface 29. The DVI digital image signal input interface 28 is an interface for inputting a digital image signal. The DVI digital image signal output interface 29 is an interface for outputting a digital image signal, and a DVI connector is used as an interface.

  The pointing device unit 19 is a pointing device corresponding to a touch pad / mouse or the like, and is connected to the computer unit 3. The control unit 21 transmits the coordinate movement information output from the pointing device to the servers 31 and 41 via the LAN interface 23. When the display unit 11 is a touch panel, the pointing device unit 19 can be omitted.

  The computer unit 3 includes a control unit 21 and a storage unit 30 necessary for operating an operating system for a personal computer or a PDA. Further, it has an Ethernet LAN interface 23 and is connected to the network by a LAN 63.

  The computer unit 3 is connected to the push button 13a via a standard keyboard interface such as a personal computer / PDA, and is connected to the display unit 11 via a standard display interface such as a personal computer / PDA. It is connected to a pointing device unit 19 via a standard pointing device interface such as a personal computer / PDA. When the display unit 11 is a touch panel, the operating system and the display unit 11 are connected via a PC / PDA standard pointing device interface.

  When the telephones 36, 37, 46, and 47 are not used as client telephones of a thin client telephone system but are used alone as a videophone apparatus, an IP softphone that performs communication using the Internet protocol is installed in the computer unit 3. Is done. It has a videophone communication unit 24 that performs call connection simultaneously with a plurality of telephones via the LAN interface 23 and simultaneously performs image or voice communication with the other telephones connected to the call.

  Similarly, when the telephones 36, 37, 46, and 47 are not used as client telephones of a thin client telephone system but are used alone as videophone apparatuses, the image processing section 22 is installed in the computer section 3. .

  The image processing unit 22 displays the screen information received from the server via the LAN interface on the display unit 11.

  The image signal captured by the camera unit 16 of the transmission source telephone is transmitted to the servers 31 and 41 via the LAN interface 23, and the image signal is communicated between the servers 31 and 41, and the image received by the transmission destination server. The screen information generated from the signal is transmitted to the telephone, and the telephone receives the screen information and displays it.

  FIG. 4 is a diagram showing the configuration of the call connection device 51 shown in FIG.

As shown in FIG. 4, the call connection device 51 in this embodiment includes a SIP server 52 that is a link establishment means, a location server 53, and a database 54 connected to the location server 53.

  The SIP server 52 uses SIP (Session Initiation Protocol) to call-connect the connection source server or telephone to the connection destination server or telephone.

  In the database 54, a server connection destination information consisting of a URL or an IP address, a telephone number of a telephone connected to the server, and a telephone connection destination information consisting of a URL or an IP address are set as one data set. In association, the call connection device 51 is registered in advance for the number of telephones in charge of call connection.

  FIG. 5 is a diagram showing the configuration of the server 31 shown in FIG. The configuration of the server 41 is the same.

  As shown in FIG. 5, the server 31 in this embodiment includes a control unit 32, an image processing unit 33, a storage unit 34, and a LAN interface 35.

  The control unit 32 controls the entire server 31.

  The image processing unit 33 converts imaging information received from the camera unit 15 of the telephones 36 and 37 via the LAN interface 35 into an image signal. Also, the image signal received from the other server 41 via the LAN interface 35 is converted into screen information that can be displayed on the display unit 11 of the telephones 36 and 37.

  The storage unit 34 holds a list of a plurality of telephones 36 and 37 connected to the server 31, and stores the telephone numbers of the respective telephones 36 and 37 and the connection destination information of the telephones 36 and 37 including URLs or IP addresses. I have it.

  Hereinafter, in the communication system configured as described above, an operation in a case where a videophone call by image communication and voice communication is performed from the telephone set 36 to the telephone set 46 between the thin client type telephone systems 56 and 57 will be described.

  First, the user inputs the telephone number of the connection destination telephone 46 using the push button 13 a of the telephone 36. The telephone 36 transmits the telephone number of the telephone 46 of the connection destination, the telephone number of the own telephone 36, and the connection destination information consisting of the URL or IP address of the own telephone 36 to the server 31 as inter-phone call connection information.

  The server 31 that has received the inter-telephone call connection information transmits the connection destination information including the URL or IP address of the server 31 and the inter-telephone call connection information to the SIP server 52 of the call control device 51.

  When the SIP server 52 receives the connection destination information including the URL or IP address of the server 31 and the inter-telephone call connection information, the SIP server 52 extracts the telephone number of the destination telephone 46 from the inter-telephone call connection information and sends it to the location server 53. The telephone number of the connection destination telephone 46 is transmitted, and the connection destination information including the URL or IP address of the connection destination telephone 46 is inquired.

  When the location server 53 receives the telephone number of the connected telephone 46, the location server 53 searches the database 54 using the telephone number as a keyword. From the database 54, the connection destination information of the server 41 composed of URL or IP address, the telephone number of the telephone 46 connected to the server 41, and the connection destination information of the telephone 46 composed of the URL or IP address, which are associated with each other. Are output. The location server 53 receives the connection destination information of the server 41 including a URL or an IP address, the telephone number of the telephone 46 connected to the server, and the connection destination information of the telephone 46 including a URL or IP address. Send to.

  The SIP server 52 recognizes that the connection destination telephone 46 is a client telephone of the thin client telephone system 57, establishes a link for image communication between the connection source server 31 and the connection destination server 41, and connects to the connection destination server 41. The establishment of a voice communication link between the original telephone set 36 and the connected telephone set 46 is started.

  The image communication link is established by the SIP server 52 using both the connection destination information of the server 31 including the connection source URL or IP address and the connection destination information of the server 41 including the connection destination URL or IP address. This is done by establishing a link between other servers.

  The voice communication link is established by the SIP server 52 using the connection destination information of the telephone set 36 consisting of the URL or IP address of the connection source and the connection destination information of the telephone set 46 consisting of the URL or IP address of the connection destination. The telephone set 46 is hooked up, and the connecting telephone set 36 recognizes that the connected telephone set 46 is hooked up to establish a telephone communication link between the two telephone sets. .

  When the SIP server 52 recognizes that the link between the two telephones has been established, the SIP server 52 instructs both the servers 31 and 41 to start image communication.

  Imaging information captured by the camera unit 16 of the telephone 36 is transmitted from the LAN interface 23 to the server 31 via the LAN 61. Also, the imaging information captured by the camera unit 16 of the telephone 46 is transmitted from the LAN interface 23 to the server 41 via the LAN 62.

  Upon receiving the imaging information, each of the servers 31 and 41 converts the received imaging information into an image signal in the image processing unit 33, and from the LAN interface 35 to the other server with which the image communication link is established. Send an image signal. Each server that has received the image signal converts the received image signal into screen information that can be displayed on the display unit 11 of the telephone in the image processing unit 33.

  The screen information converted by the server 31 is transmitted from the LAN interface 35 to the telephone set 36 via the LAN 61 and displayed on the display unit 11 of the telephone set 36. The screen information converted by the server 41 is transmitted from the LAN interface 35 to the telephone 46 via the LAN 62 and displayed on the display unit 11 of the telephone 46.

  The imaging information captured by each telephone is transmitted to the server, further transmitted to the other server, converted into screen information, and displayed on the display unit 11 of the telephone under the server. Both telephones that have established a telephone communication link perform voice communication while referring to screen information displayed on the telephone display.

(Other examples)
FIG. 6 is a diagram showing another embodiment of the communication system of the present invention.

  As shown in FIG. 6, this embodiment is configured by connecting a thin client telephone system 56, a plurality of telephones 66 and 67 having a videophone function, and a call control device 51 via a LAN 63.

  The thin client type telephone system 56 is configured by connecting two client type telephones 36 and 37 and a server 31 having the telephones 36 and 37 under the control of the LAN 61. The server 31 is connected to the LAN 63. Note that the number of telephones 36 and 37 that the server 31 has is not limited to two as illustrated.

  The configurations of the telephones 36, 37, 66, and 67 are the same as those shown in FIGS. 2 and 3, and the configurations of the server 31 and the call control device 51 are the same as those shown in FIGS. It is.

  Hereinafter, in the communication system configured as described above, an operation in the case where a videophone call with an image and sound is performed between the telephone set 36 of the thin client type telephone system 56 and the telephone set 66 having a videophone function will be described. To do.

  The user inputs the telephone number of the destination telephone 66 using the push button 13 a of the telephone 36. The telephone 36 transmits the telephone number of the telephone 66 of the connection destination, the telephone number of the own telephone 36, and the connection destination information consisting of the URL or IP address of the own telephone 36 to the server 31 as inter-phone call connection information.

  The server 31 that has received the inter-telephone call connection information transmits to the SIP server 52 of the call control device 51 the connection destination information consisting of the URL or IP address of the server 31 and the inter-telephone call connection information.

  When the SIP server 52 receives the connection destination information consisting of the URL or IP address of the server 31 and the inter-telephone call connection information, the SIP server 52 extracts the telephone number of the destination telephone 66 from the inter-telephone call connection information and sends it to the location server 53. The telephone number of the connection destination telephone 66 is transmitted, and the connection destination information consisting of the URL or IP address of the connection destination telephone 66 is inquired.

  When the location server 53 receives the telephone number of the connected telephone 66, the location server 53 searches the database 54 using the telephone number as a keyword. From the database 54, the telephone number of the telephone 66 and the connection destination information of the telephone 66 consisting of a URL or an IP address are output. The location server 53 transmits the telephone number of the telephone 66 and the connection destination information of the telephone 66 consisting of a URL or an IP address to the SIP server 52.

  The SIP server 52 recognizes that the connection destination telephone 66 is a telephone having a videophone function, establishes a link for image communication between the connection source server 31 and the connection destination telephone 66, and connects to the connection source telephone. The establishment of a voice communication link between the telephone 36 and the telephone 66 of the connection destination is started.

  The link of image communication is established by the SIP server 52 using the connection destination information of the server 31 consisting of the URL or IP address of the connection source and the connection destination information of the telephone 66 consisting of the URL or IP address of the connection destination. This is performed so as to establish a link between the server 31 and the telephone 66.

  The voice communication link is established by the SIP server 52 using the connection destination information of the telephone set 36 consisting of the URL or IP address of the connection source and the connection destination information of the telephone set 66 consisting of the URL or IP address of the connection destination. The connection-destination telephone 66 hooks up, and the connection-source telephone 36 recognizes that the connection-destination telephone 66 has hooked up, thereby establishing a telephone communication link between the two telephones. .

  When the SIP server 52 recognizes that the link between the two telephones has been established, the SIP server 52 instructs the server 31 and the telephone 66 to start image communication.

  Imaging information captured by the camera unit 16 of the telephone 36 is transmitted from the LAN interface 23 to the server 31 via the LAN 61. When the server 31 receives the imaging information, the image processing unit 33 converts the received imaging information into an image signal, and transmits the image signal from the LAN interface 35 to the telephone 66 that has established a link for image communication. Receiving the image signal, the telephone 66 converts the image signal into screen information that can be displayed on the display unit 11 of the telephone 66 in the image processing unit 22 and displays it on the display unit 11.

  On the other hand, image information captured by the camera unit 16 of the telephone 66 is converted into an image signal by the image processing unit 22 and transmitted from the LAN interface 23 to the server 31 through which the image communication link is established via the LAN 61. The

  Upon receiving the image signal, the server 31 converts the image signal into screen information that can be displayed on the display unit 11 of the telephone 36 in the image processing unit 33. The screen information is transmitted from the LAN interface 35 to the telephone set 36 via the LAN 61 and displayed on the display unit 11 of the telephone set 36.

  Both telephones that have established a telephone communication link perform voice communication while referring to screen information displayed on the display arm 11 of the telephone.

  The server of the thin client type telephone system has a telephone directory function. The server 31 stores in the storage unit 34 a connection destination name composed of a plurality of connection destination names and a telephone number of the connection destination name. When the control unit 32 generates image information of a list of connection destination names from a plurality of connection destination names and the phone numbers of the connection destination names, the image processing unit 33 displays the screen information to be displayed on the display unit 11 of the subordinate telephones 36 and 37. Convert. The telephones 36 and 37 receive the screen information and display a screen of a connection destination name list on the display unit 11.

  When the connection destination name of the telephone set 46 is selected by operating the pointing device (mouse) unit 19 of the telephone set 36, the telephone set 36 is connected to the telephone number of the connection destination telephone set 46, the telephone number of the own telephone set 36, and the own telephone set. The connection destination information consisting of 36 URLs or IP addresses is transmitted to the server 31 as inter-telephone call connection information.

  The server 31 that has received the inter-telephone call connection information transmits to the SIP server 52 of the call control device 51 the connection destination information consisting of the URL or IP address of the server 31 and the inter-telephone call connection information.

  The subsequent operation is the same as that in the case where a call connection is made from the telephone set 36 to the telephone set 46 between the above-described thin client type telephone systems 56 and 57.

  The server of the thin client type telephone system has an information transmission function. The server 31 generates an information display screen using information obtained from a plurality of information transmission terminals (not shown) connected to the LAN 63. The image information on the information display screen is converted by the image processing unit 33 into screen information to be displayed on the display unit 11 of the subordinate telephones 36 and 37. The telephones 36 and 37 receive the screen information and display an information display screen on the display unit 11.

It is a figure which shows one Example of the communication system of this invention. It is a figure which shows the structural example of the telephone set shown in FIG. 1, (a) is a schematic overview figure, (b) is a figure which shows the structure of the board surface shown to (a). FIG. 3 is a diagram mainly showing a hardware configuration of the telephone set shown in FIG. 2. It is a figure which shows the structure of the call connection apparatus shown in FIG. It is a figure which shows the structure of the server shown in FIG. It is a figure which shows the other Example of the communication system of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Handset part 2 Hook switch 3 Computer part 4 Main body part 5 Board surface 5a Telephone operation part 11 Display part 12 Line button part 13 Key part 13a Push button 14 Function button part 14a Reset button 14b Hold button 14c Transfer button 14d Hook button 15 Digiless Button unit 16 Camera unit 17 Speaker unit 18 Microphone unit 19 Pointing device unit 21, 32 Control unit 22, 33 Image processing unit 23, 35 LAN interface 24 Videophone communication unit 25 UBS interface 26 RGB analog image signal input interface 27 RGB analog image Signal output interface 28 DVI digital image signal input interface 29 DVI digital image signal output interface 30, 34 Storage unit 31, 41 Server 36 37,46,47,66,67 telephone 38 battery 51 call controller 56 a thin client telephone system 61 to 63 LAN

Claims (7)

A communication system for performing image communication and voice communication between a thin client type telephone system comprising a client type telephone and a server having the client type telephone under control,
Control means for establishing a link between the thin client telephone systems;
The control means includes
A database in which the telephone number and connection destination information of the client type telephone and the connection destination information of a server under the client type telephone are registered as a set;
Referring to the database, for one call, for the image communication, the server has a client phone that is a source of image information and a client phone that is a destination of the image information. A link is established between these two servers by using connection destination information of each server, and for the voice communication, a client phone that is a voice information transmission source and a client phone that is a voice information transmission destination Link establishing means for establishing a link between these two client-type telephones using respective telephone numbers;
For one call, the image communication is conducted through a pre-Symbol server Te between the client phone using the established link, the voice communication, the client by using the established link A communication system that is performed without using the server between telephones. The communication system according to claim 1 ,
The server converts an image signal received as image information into information that can be displayed on the client phone under its control, and transmits the information to the client phone. The communication system according to claim 1 ,
The server has a telephone directory function including connection information of the client-type telephone, and transmits a list of connection information of the client-type telephone to a subordinate client-type telephone. The communication system according to claim 1 ,
The said server has the information transmission function which transmits the acquired information via a network, The said acquired information is transmitted to the subordinate client type telephone, The communication system characterized by the above-mentioned. The communication system according to claim 1 ,
The client phone is
A handset,
A hook switch that can detect on-hook and off-hook mechanically;
A communication system comprising a push button capable of mechanically specifying a communication partner. A communication method for performing image communication and voice communication between a thin client type telephone system comprising a client type telephone and a server having the client type telephone under control,
With reference to a database in which the telephone number and connection destination information of the client-type telephone and the connection destination information of a server under the client-type telephone are registered as a set, the image communication for one call A link between the two servers using connection destination information of the server having the client type telephone serving as the image information transmission source and the server having the client type telephone serving as the image information transmission destination For the voice communication, a link is established between these two client-type telephones using the telephone numbers of the client-type telephone that is the voice information transmission source and the client-type telephone that is the voice information transmission destination. Establish
For one call, the image communication is conducted through a pre-Symbol server Te between the client phone using the established link, the voice communication, the client by using the established link A communication method performed without using the server between telephones. The communication method according to claim 6 ,
A communication method, comprising: converting an image signal received as image information at the server into information that can be displayed on the client phone under its control and transmitting the information to the client phone.

Images