Abstract:
A connection controller for controlling connection with a partner terminal with which communication is performed via a predetermined communication service includes setting information storage means for storing a record of setting information for the connection with the partner terminal, interruption processing means for temporarily stopping communication with a first terminal in the process of the communication with the first terminal and for starting communication with a second terminal, recovery processing means for restarting the communication with the first terminal on the basis of information stored in the setting information storage means when the interrupting communication with the second terminal terminates, terminal detection means for detecting a third terminal, and transfer processing means for starting communication between the third terminal detected by the terminal detection means and a terminal designated by the first terminal and disconnecting the communication with the first terminal in the process of the interrupting communication.

Description:
CROSS REFERENCES TO RELATED APPLICATIONS  
       [0001]     The present invention contains subject matter related to Japanese Patent Application JP 2005-053373 filed in the Japanese Patent Office on Feb. 28, 2005, the entire contents of which are incorporated herein by reference.  
       BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     The present invention relates to a connection controller that controls connection with a terminal with which communication is performed via a predetermined communication service, a communication system including the connection controller, and a connection control method, and more particularly, to a connection controller, a communication system, and a connection control method in which the convenience of a user of original communication is enhanced when communication interruption occurs.  
         [0004]     2. Description of the Related Art  
         [0005]     In recent years, due to the great development in communication technologies, transmission and reception of audio and image signals via networks has been generalized. Accordingly, communication services using images and sound, such as videophone services and teleconferencing services, become popular.  
         [0006]     In actual videophone or teleconferencing services, in the process of communication using terminals, a user of a terminal may communicate and have a conversation with a party with which the user is not currently communicating or may receive a connection request from the party. Under such circumstances, a videophone terminal that enhances serviceability is available (see, for example, Japanese Unexamined Patent Application Publication No. 5-327914 (paragraphs [0011]-[0015] and FIG. 1)). For example, in the process of communication with a second videophone terminal, when receiving a call from a third videophone terminal, this videophone terminal receives from the third videophone terminal an information image indicating the call reception, combines the received information image with an image received from the second videophone terminal, and displays the combined image. In addition, a teleconferencing system in which, in the process of a teleconferencing service, a teleconference terminal is capable of receiving an interruption report via a circuit for reporting interruption, the circuit being provided independent of a teleconference circuit, is available (see, for example, Japanese Unexamined Patent Application Publication No. 11-136368 paragraphs [0021]-[0023] and FIG. 2).  
       SUMMARY OF THE INVENTION  
       [0007]     As described above, for example, interruption of communication using teleconference terminals by communication with a party with which a user of a terminal is not currently communicating may often be required. In an actual conference, however, restarting communication with an original party with which the user communicated before the interruption is often desired in the process of interrupting communication or after the interrupting communication terminates. However, for such cases, no procedure has been suggested for improving user-friendless so as to be able to communicate with the original party, such as recovery of communication with the original party by a simple operation.  
         [0008]     It is desirable to provide a connection controller capable of enhancing the convenience of a user of communication when the communication is interrupted.  
         [0009]     It is also desirable to provide a communication system capable of enhancing the convenience of a user of communication when the communication using a terminal is interrupted.  
         [0010]     In addition, it is desirable to provide a connection control method capable of enhancing the convenience of a user of communication when the communication is interrupted.  
         [0011]     A connection controller according to an embodiment of the present invention for controlling connection with a partner terminal with which communication is performed via a predetermined communication service includes setting information storage means for storing a record of setting information for the connection with the partner terminal with which the communication is performed, interruption processing means for temporarily stopping communication with a first terminal in the process of the communication with the first terminal and for starting communication with a second terminal, recovery processing means for restarting the communication with the first terminal on the basis of information stored in the setting information storage means when the interrupting communication with the second terminal terminates, terminal detection means for detecting a third terminal, and transfer processing means for starting communication between the third terminal detected by the terminal detection means and a terminal designated by the first terminal and disconnecting the communication with the first terminal in the process of the interrupting communication with the second terminal.  
         [0012]     In such a connection controller, the setting information storage means stores a record of setting information for connection with a partner terminal with which communication is performed, and the interruption processing means temporarily stops communication with a first terminal in the process of the communication with the first terminal and starts communication with a second terminal. When the interrupting communication with the second terminal terminates, the recovery processing means restarts the communication with the first terminal on the basis of information stored in the setting information storage means. When the interrupting communication with the second terminal is maintained, the transfer processing means starts communication between a third terminal detected by the terminal detection means and a terminal designated by the first terminal and disconnects the communication with the first terminal, and communication using the third terminal can be performed.  
         [0013]     A connection control method according to an embodiment of the present invention for controlling connection with a partner terminal with which communication is performed via a predetermined communication service includes the steps of storing, by setting information storage means, a record of setting information for the connection with the partner terminal with which the communication is performed; temporarily stopping, by interruption processing means, communication with a first terminal in the process of the communication with the first terminal and starting communication with a second terminal; restarting, by recovery processing means, the communication with the first terminal on the basis of information stored in the setting information storage means when the interrupting communication with the second terminal terminates; detecting, by terminal detection means, a third terminal when the interrupting communication with the second terminal is maintained; and starting, by transfer processing means, communication between the third terminal detected by the terminal detection means and a terminal designated by the first terminal and disconnecting the communication with the first terminal.  
         [0014]     In such a connection control method, the setting information storage means stores a record of setting information for connection with a partner terminal with which communication is performed, the interruption processing means temporarily stops communication with a first terminal in the process of the communication with the first terminal and starts communication with a second terminal. When the interrupting communication with the second terminal terminates, the recovery processing means restarts the communication with the first terminal on the basis of information stored in the setting information storage means. When the interrupting communication with the second terminal is maintained, the transfer processing means starts communication between a third terminal detected by the terminal detection means and a terminal designated by the first terminal and disconnects the communication with the first terminal, an communication using the third terminal can be performed.  
         [0015]     In the connection controller described above, if restart of the communication with the first terminal is; required after the interrupting communication with the second terminal starts, the communication with the first terminal can be automatically recovered by the recovery processing means without requiring a user of the communication with the first terminal to perform setting processing for restarting the communication. If a user of the first terminal desires to communicate with a user of the second terminal while the interrupting communication is maintained, the communication between the third terminal detected by the terminal detection means and the terminal designated by the first terminal can be started by the transfer processing means without requiring the user of the first terminal to perform setting processing for starting newly established communication, and the user of the first terminal is able to communicate, using the third terminal, with the user of the second terminal. Thus, the convenience of the users of the first and second terminals, which are subjected to interruption, can be enhanced.  
         [0016]     In addition, in the connection control method described above, if restart of the communication with the first terminal is required after the interrupting communication with the second terminal starts, the communication with the first terminal can be automatically recovered by the recovery processing means without requiring a user of the communication with the first terminal to perform setting processing for restarting the communication. If a user: of the first terminal desires to communicate with a user of the second terminal while the interrupting communication is maintained, the communication between the third terminal detected by the terminal detection means and the terminal designated by the first terminal can be started by the transfer processing means without requiring the user of the first terminal to perform setting processing for starting newly established communication, and the user of the first terminal is able to communicate, using the third terminal, with the user of the second terminal. Thus, the convenience of the users of the first and second terminals, which are subjected to interruption, can be enhanced. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0017]      FIG. 1  shows an example of the configuration of a communication system according to an embodiment of the present invention;  
         [0018]      FIG. 2  is a block diagram showing the internal configuration of a teleconference terminal;  
         [0019]      FIG. 3  is a block diagram showing the internal configuration of a mobile terminal;  
         [0020]      FIG. 4  is a first illustration for explaining the outline of communication interruption;  
         [0021]      FIG. 5  is a second illustration for explaining the outline of communication interruption;  
         [0022]      FIG. 6  is a third illustration for explaining the outline of communication interruption;  
         [0023]      FIG. 7  is a fourth illustration for explaining the outline of communication interruption;  
         [0024]      FIG. 8  is a flowchart of a process performed by a teleconference terminal in a conference room from interruption of communication to recovery of the communication or to start of transfer processing;  
         [0025]      FIG. 9  is a flowchart of a process performed by the teleconference terminal in the conference room when the original communication session is recovered after the communication interruption;  
         [0026]      FIG. 10  is a flowchart of a process performed by the teleconference terminal in the conference room when the original communication session is transferred to another communication session after the communication interruption; and  
         [0027]      FIGS. 11A and 11B  show examples of a process for transfer to a communication session newly established using a mobile terminal. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0028]     Embodiments of the present invention will be described with reference to the drawings.  
         [0029]      FIG. 1  shows an example of the configuration of a communication system according to an embodiment of the present invention.  
         [0030]     In  FIG. 1 , an example of the configuration of the communication system in which, for example, two communication services, that is, a teleconferencing service and an Internet Protocol (IP) telephone service, are implemented on a network based on a Transmission Control Protocol (TCP)/IP is shown. In addition, in this example, a case where a teleconference or IP telephone service is implemented between three conference rooms that are remote from each other, that is, conference rooms A, B, and C, is assumed.  
         [0031]     In such a communication system, as shown in  FIG. 1 , teleconference terminals  10   a ,  10   b , and  10   c  and wireless local-area network (LAN) access points (APs)  20   a ,  20   b , and  20   c  are connected to each other via a LAN (including a wide area network (WAN) connected to a LAN)  100 . In addition, mobile terminals  30   a - 1  and  30   a - 2  are capable of being wirelessly connected to the LAN  100  via the wireless LAN access point  20   a . Mobile terminals  30   b  and  30   c  are capable of being wirelessly connected to the LAN  100  via the wireless LAN access points  20   b  and  20   c , respectively.  
         [0032]     The teleconference terminals  10   a  to  10   c  are used to have a teleconference. The teleconference terminals  10   a  to  10   c  are capable of transmitting and receiving image signals and audio signals via the LAN  100 . In addition, each of the teleconference terminals  10   a  to  10   c  is provided with a wireless communication interface for performing communication based on a short-distance wireless system. Thus, the teleconference terminal  10   a  is capable of performing-contactless communication with the mobile terminals  30   a - 1  and  30   a - 2  based on the short-distance wireless system. Similarly, the teleconference terminals  10   b  and  10   c  are capable of performing contactless communication with the mobile terminals  30   b  and  30   c , respectively, based on the short-distance wireless system.  
         [0033]     The wireless LAN access points  20   a  to  20   c  are connected to the LAN  100  via wired cables. The wireless LAN access points  20   a  to  20   c  function as base stations used for wireless LAN devices (in this case, the mobile terminals  30   a - 1 ,  30   a - 2 ,  30   b , and  30   c ) to be wirelessly connected to this circuit. In addition, the wireless LAN access points  20   a  to  20   c  may have various security functions necessary for wireless transmission and reception.  
         [0034]     The mobile terminals  30   a - 1 ,  30   a - 2 ,  30   b , and  30   c  function as remote stations to be connected to the LAN  100  via the wireless LAN access points  20   a  to  20   c . This connection enables the mobile terminals  30   a - 1 ,  30   a - 2 ,  30   b , and  30   c  to function as conversation terminals in an IP telephone service based on a Voice over Internet Protocol (VoIP). In addition, each of the mobile terminals  30   a - 1 ,  30   a - 2 ,  30   b , and  30   c  is provided with a communication interface for performing communication based on the short-distance wireless system. Thus, the mobile terminals  30   a - 1 ,  30   a - 2 ,  30   b , and  30   c  are capable of performing contactless communication with the teleconference terminals  10   a  to  10   c  based on the short-distance wireless system.  
         [0035]     In this communication system, the teleconference terminal  10   a  and the wireless LAN access point  20   a  are installed in the conference room A, and two of users of the teleconference terminal  10   a  are able to perform conversation via the IP telephone service using the mobile terminals  30   a - 1  and  30   a - 2 . In addition, the mobile terminals  30   a - 1  and  30   a - 2  are capable of communicating with the teleconference terminal  10   a  via short-distance wireless communication. When the teleconference terminal  10   a  detects and authenticates the mobile terminal  30   a - 1  or  30   a - 2  via short-distance wireless communication in the process of execution of a teleconference application, the teleconference terminal  10   a  is capable of transmitting and receiving information to and from the mobile terminal  30   a - 1  or  30   a - 2  via short-distance wireless communication or is then capable of performing an operation by being connected to the mobile terminal  30   a - 1  or  30   a - 2  via the LAN  100  and receiving, for example, a control command from the mobile terminal  30   a - 1  or  30   a - 2 .  
         [0036]     In addition, the teleconference terminal  10   b  and the wireless LAN access point  20   b  are installed in the conference room B, and the teleconference terminal  10   c  and the wireless LAN access point  20   c  are installed in the conference room C. One of users of the teleconference terminal  10   b  who carries the mobile terminal  30   b  is able to perform conversation via the wireless LAN access point  20   b . One of users of the teleconference terminal  10   c  who carries the mobile terminal  30   c  is able to perform conversation via the wireless LAN access point  20   c . In addition, the mobile terminals  30   b  and  30   c  are capable of performing communication with the teleconference terminals  10   b  and  10   c , respectively, via the short-distance wireless system. After being detected and authenticated by the teleconference terminals  10   b  and  10   c , respectively, the mobile terminals  30   b  and  30   c  are capable of transmitting and receiving information to and from the teleconference terminals  10   b  and  10   c , respectively, based on the short-distance communication or via the LAN  100 .  
         [0037]      FIG. 2  is a block diagram showing the internal configuration of each of the teleconference terminals  10   a  to  10   c.    
         [0038]     The teleconference terminals  10   a  to  10   c  each have the same configuration. Referring to  FIG. 2 , each of the teleconference terminals  10   a  to  10   c  includes a teleconference processing unit  11 , an image processing unit  12 , an audio processing unit  13 , a connection controller  14 , a LAN interface  15 , a short-distance wireless interface  16 , and an input unit  17 .  
         [0039]     The teleconference processing unit  11  performs processing for implementing a teleconference. More specifically, the teleconference processing unit  11  performs basic processing for receiving a teleconferencing service, such as setting for connection with a partner terminal of the teleconference, setting for image-capturing and recording functions, and setting for outputting of image and audio signals, and input and output processing of image signals and audio signals, that is, processing of outputting to the connection controller  14  or the LAN interface  15  image signals received from the image processing unit  12  and audio signals received from the audio processing unit  13  and outputting to the image processing unit  12  and the audio processing unit  13  image signals and audio signals, respectively, input from the LAN interface  15  or the connection controller  14 .  
         [0040]     The image processing unit  12  converts an image signal received from an externally connected camera  121  into a digital signal, encodes the digital signal into a predetermined format, and outputs the encoded signal to the teleconference processing unit  11 . In addition, the image processing unit  12  decodes an image signal received from the teleconference processing unit  11  into an analog signal, outputs the analog signal to an externally connected monitor  122 , and causes the monitor  122  to display the analog signal. The audio processing unit  13  converts an audio signal received from an externally connected microphone  131  into a digital signal, encodes the digital signal into a predetermined format, and outputs the encoded signal to the teleconference processing unit  11 . In addition, the audio processing unit  13  decodes an audio signal received from the teleconference processing unit  11  into an analog signal, outputs the analog signal to an externally connected speaker  132 , and causes the speaker  132  to reproduce the analog signal.  
         [0041]     The connection controller  14  performs processing for enabling the mobile terminals  30   a - 1 ,  30   a - 2 ,  30   b , and  30   c  detected by the short-distance wireless interface  16  to control the operation of the teleconference processing unit  11 . For example, in accordance with a signal received from the input unit  17  or a control command received via the short-distance wireless interface  16  or the LAN interface  15  from the mobile terminal  30   a - 1 ,  30   a - 2 ,  30   b , or  30   c , the connection controller  14  controls connection with a conference partner and controls transfer of image signals and audio signals between the teleconference processing unit  11  and the LAN interface  15 . In addition, the connection controller  14  performs authentication processing and device management processing for the mobile terminal  30   a - 1 ,  30   a - 2 ,  30   b , or  30   c  detected by the short-distance wireless interface  16 .  
         [0042]     The LAN interface  15  is connected to the LAN  100 , and controls transfer of signals between the LAN  100  and the connection controller  14 . The short-distance wireless interface  16  is used for performing communication with the mobile terminals  30   a - 1 ,  30   a - 2 ,  30   b , and  30   c  via the short-distance wireless system. In this embodiment, an electromagnetic induction communication system using a wireless IC chip is adopted as the short-distance wireless system. The short-distance wireless interface  16  includes a reader/writer that supplies electric power to the wireless IC chip provided in each of the mobile terminal  30   a - 1 ,  30   a - s ,  30   b , and  30   c  and that transmits and receives signals to and from the wireless IC chip. The input unit  17  includes an input key and the like. The input unit  17  outputs to the connection controller  14  a control signal corresponding to operation control input by a user.  
         [0043]     A function for causing the mobile terminals  30   a - 1 ,  30   a - 2 ,  30   b , or  30   c  to control teleconference processing may be provided as a device independent of a teleconference terminal. In this case, for example, the teleconference terminal includes an interface for the LAN  100 . The teleconference terminal communicates with a partner terminal and transmits and receives images and sound to and from the partner terminal under self-control. In addition, functions of the connection controller  14  and the short-distance wireless interface  16  shown in  FIG. 2  are provided as external expansion devices. When the expansion devices are connected to the teleconference terminal using communication means, such as a universal serial bus (USB), communication of the teleconference terminal via the LAN  100  is performed through the expansion devices, and the teleconference terminal and the mobile terminal  30   a - 1 ,  30   a - 2 ,  30   b , and  30   c  are capable of being used as control terminals of a teleconference.  
         [0044]      FIG. 3  is a block diagram showing the internal configuration of each of the mobile terminals  30   a - 1 ,  30   a - 2 ,  30   b , and  30   c.    
         [0045]     The mobile terminals  30   a - 1 ,  30   a - 2 ,  30   b , and  30   c  each have the same configuration. Referring to  FIG. 3 , each of the mobile terminals  30   a - 1 ,  30   a - 2 ,  30   b , and  30   c  includes a controller  31 , a wireless LAN interface  32 , a short-distance wireless interface  33 , an audio processing unit  34 , a display processing unit  35 , an input unit  36 , a microphone  341 , a speaker  342 , and a monitor  351 .  
         [0046]     The controller  31  includes a central processing unit (CPU), a memory in which programs and various data performed by the CPU are stored, and the like. The controller  31  generally controls blocks inside each of the mobile terminals  30   a - 1 ,  30   a - 2 ,  30   b , and  30   c . More specifically, the controller  31  performs conversation processing over the IP telephone service via the wireless LAN interface  32 , in other words, performs processing of outputting to the wireless LAN interface  32  audio signals received from the audio processing unit  34  and outputting to the audio processing unit  34  audio signals received via the wireless LAN interface  32 . In addition, the controller  31  performs processing for causing various data, such as address information and control commands, to be transferred via the wireless LAN interface  32  or the short-distance wireless interface  33  and processing for generating display information for the monitor  351  and outputting the display information to the display processing unit  35 .  
         [0047]     The wireless LAN interface  32  is an interface circuit to be connected to the LAN  100  via the wireless LAN access points  20   a  to  20   c . The wireless LAN interface  32  demodulates signals received from the wireless LAN access points  20   a  to  20   c , and supplies the demodulated signals to the controller  31 . In addition, the wireless LAN interface;  32  modulates signals output from the controller  31 , and wirelessly transmits the modulated signals to the wireless LAN access points  20   a  to  20   c.    
         [0048]     The short-distance wireless interface  33  includes a wireless IC chip for performing communication based on the electromagnetic induction communication system, an antenna for transmitting and receiving signals, and the like. The short-distance wireless interface  33  performs an operation by generating electric power in accordance with electric waves received from readers/writers (the short-distance wireless interface  16 ) provided in the teleconference terminals  10   a  to  10   c , and transmits and receives signals to and from the teleconference terminals  10   a  to  10   c.    
         [0049]     The audio processing unit  34  converts an audio signal received from the microphone  341  into a digital signal, encodes the digital signal into a predetermined format, and outputs the encoded signal to the controller  31 . In addition, the audio processing unit  34  decodes an audio signal received from the controller  31  into an analog signal, outputs the analog signal to the speaker  342 , and causes the speaker  342  to reproduce the analog signal. The display processing unit  35  generates an image signal on the basis of display information generated by the controller  31 , outputs the image signal to the monitor  351 , which is, for example, a liquid crystal display (LCD), and causes the monitor  351  to display the image signal. The input unit  36  includes an input key and the like. The input unit  36  outputs to the controller  31  a control signal corresponding to operation control input by the user.  
         [0050]     Although an electromagnetic induction communication system is adopted as a short-distance wireless communication system for performing direct communication between the teleconference terminals  10   a  to  10   c  and the mobile terminals  30   a - 1 ,  30   a - 2 ,  30   b , and  30   c  in this embodiment, other systems, such as a Bluetooth™ system and an infrared-ray communication system, may be adopted. In addition, instead of wireless communication, a communication system using a relatively short wired cable, such as a USB or IEEE (Institute of Electrical and Electronic Engineers) 1394, may be adopted.  
         [0051]     An operation in such a communication system performed when a communication session based on a teleconferencing service is interrupted by another communication session is described next. In this communication system, for example, after the interrupting communication session terminates, the original communication session immediately before the interruption can be recovered easily. In addition, in the process of the interrupting communication session, the original communication session can be transferred to another communication using a mobile terminal.  
         [0052]     The outline of the operation of the entire system will be described with reference to FIGS.  4  to  7 .  
         [0053]     FIGS.  4  to  7  illustrate the outline of communication interruption.  
         [0054]     Referring to  FIG. 4 , users A 1  and B 1  are having a teleconference using the teleconference terminals  10   a  and  10   b , respectively (step S 11 ). This communication session is represented as session  1 - 1 . A teleconference can be started by operating only the teleconference terminals  10   a  and  10   b . However, for example, a state in which the users A 1  and B 1  perform conversation over an IP telephone service using the mobile terminals  30   a - 1  and  30   b , respectively, can be transferred to communication between the teleconference terminals  10   a  and  10   b.    
         [0055]     In this case, for example, when the user A 1  brings the mobile terminal  30   a - 1  closer to the teleconference terminal  10   a , the teleconference terminal  10   a  acknowledges the mobile terminal  30   a - 1  via the short-distance wireless system, and reports to the mobile terminal  30   a - 1  the IP address of the teleconference terminal  10   a . The mobile terminal  30   a - 1  reports, via the IP telephone service, to the mobile terminal  30   b  the reported IP address. The mobile terminal  30   b  reports, via short-distance wireless communication or an IP network (that is, the LAN  100 ), to the teleconference terminal  10   b  the reported IP address. Then, the mobile terminal  30   b  requires the teleconference terminal  10   b  to establish connection with the teleconference terminal  10   a.    
         [0056]     Each of the teleconference terminals  10   a  to  10   c  has a function to store setting information for connection, such as an IP address and a port number, of a communication partner in a teleconference as history information. With this function, when the teleconferencing communication starts, each of the teleconference terminals  10   a  and  10   b  stores setting information of a corresponding partner terminal (step S 12 ).  
         [0057]     Then, in the process of the teleconference communication based on the communication session  1 - 1 , for example, the necessity of referring to a user C 1  in the conference room C occurs. In this case, for example, a user A 2  in the conference room A originates a call to the mobile terminal  30   c  of the user C 1 , and conversion over the IP telephone service starts (step S 13 ). This communication is represented as session  2 - 1 . Then, if the communication with the user C 1  requires images, as well as sound, a teleconference based on connection between the teleconference terminal  10   c  of the user C 1  and the teleconference terminal  10   a  in the conference room A is required.  
         [0058]     Here, in order to transfer the communication (session  2 - 1 ) between the mobile terminal  30   a - 2  of the user A 2  and the mobile terminal  30   c  of the user C 1  to communication (session  2 - 2  (see  FIG. 5 )) between the teleconference terminal  10   a  and the teleconference terminal  10   c , the mobile terminals  30   a - 2  and  30   c  are brought closer to the teleconference terminals  10   a  and  10   c , respectively. Then, after the mobile terminals  30   a - 2  and  30   c  are detected and authenticated, both the mobile terminals  30   a - 2  and  30   c  (or one of the mobile terminals  30   a - 2  and  30   c ) require(s) to transfer the communication (steps S 14  and S 15 ). The users A 2  and C 1  may directly operate the teleconference terminals  10   a  and  10   c , respectively, so that communication between the teleconference terminals  10   a  and  10   c  can start.  
         [0059]     Since the teleconference terminal  10   a  is communicating with the teleconference terminal  10   b  in the session  1 - 1 , the session  1 - 1  is interrupted by the session  2 - 2 . Referring to  FIG. 5 , the teleconference terminal  10   a  causes the session  1 - 1  with the teleconference terminal  10   b  to pause (step S 21 ). Then, the teleconference terminal  10   a  starts communication with the teleconference terminal  10   c  in the session  2 - 2  (step S 22 ). In the session  1 - 1 , although teleconference processing, that is, transmission and reception of image data and audio data, stops, for example, predetermined information, such as a status report, may be transmitted and received with a predetermined interval.  
         [0060]     In accordance with the processing described above, the user A 2  in the conference room A is able to have a teleconference with the user C 1  in the conference room C. If the teleconference with the conference room B restarts after termination of the teleconference with the conference room C, as shown in  FIG. 6 , the teleconference terminal  10   a  terminates the communication session  2 - 2  with the teleconference terminal  10   c  (step S 31 ). Then, the teleconference terminal  10   a  extracts setting information of the session  1 - 1  from among stored setting information records (step S 32 ). Then, the teleconference terminal  10   a  is connected to the teleconference terminal  10   b  using the extracted setting information, and restarts the teleconference (step S 33 ). In accordance with the processing described above, the users A 1 , A 2 , and B 1  do not need to re-perform an operation for establishing connection between the teleconference terminals  10   a  and  10   b , and are able to easily restart a teleconference with the original partner.  
         [0061]     In contrast, in a case where the teleconference with the conference room C needs to be continued for a while, for example, it will be convenient to be able to contact a user in the conference room B over the IP telephone service or to be able to continue the conference with the conference room B using the IP telephone service, according to need. In such a case, as shown in  FIG. 7 , in a state where the session  2 - 2  between the teleconference terminals  10   a  and  10   c  is continued (step S 41 ), the users A 1  and B 1  require, using the mobile terminals  30   a - 1  and  30   b  via short-distance wireless communication or the like, the teleconference terminals  10   a  and  10   b  to transfer the communication session  1 - 1  (steps S 42  and  43 ). Such transfer requests may be performed by operation control input to the teleconference terminals  10   a  and  10   b . In this case, however, the teleconference terminals  10   a  and  10   b  must acknowledge the mobile terminals  30   a - 1  and  30   b , respectively, in advance via the short-distance wireless system.  
         [0062]     By communicating with the mobile terminal  30   a - 1 , the teleconference terminal  10   a  is capable of acquiring setting information of the mobile terminal  30   a - 1  necessary for connection via the IP telephone service, such as an IP address. Thus, the teleconference terminal  10   a  is capable of starting communication (session  1 - 2 ) between the mobile terminals  30   a - 1  and  30   b  over the IP telephone service by reporting, via the teleconferencing session  1 - 1 , to the teleconference terminal  10   b  the acquired setting information and by requiring the teleconference terminal  10   b  to cause the mobile terminal  30   b  to originate a call. Alternatively, the teleconference terminal  10   a  is capable of starting the session  1 - 2  by acquiring, via the teleconference terminal  10   b , setting information of the mobile terminal  30   b , such as an IP address, and by reporting to the mobile terminal  30   a - 1  the setting information. Then, by disconnecting the original session  1 - 1  when the session  1 - 2  starts, transfer of the communication session is performed (step S 44 ).  
         [0063]     In accordance with the processing described above, the users A 1  and B 1  are able to transfer a teleconferencing communication session to a communication session between the mobile terminals  30   a - 1  and  30   b  by an easy operation without performing an operation for setting a telephone number, an IP address, and the like, and are able to continue conversation.  
         [0064]     Although the session  1 - 1  is transferred to the session  1 - 2  between the mobile terminals  30   a - 1  and  30   b  in the operation described above, for example, the session  1 - 1  may be transferred to another communication session newly established between the mobile terminal  30   a - 1  and the teleconference terminal  10   b.    
         [0065]     A more specific example of a process performed when communication is interrupted is described next.  
         [0066]      FIG. 8  is a flowchart of a process performed by the teleconference terminal  10   a  from interruption of communication to recovery of the communication or to start of transfer processing.  
         [0067]     In step S 101 , the connection controller  14  is connected to the teleconference terminal  10   b  in the conference room B via the LAN interface  15  (session  1 - 1 ), and causes the teleconference processing unit  11  to start teleconference processing using image and audio data.  
         [0068]     In step S 102 , the connection controller  14  stores setting information for communication (for example, an IP address of the teleconference terminal  10   b ) for restarting the session  1 - 1 .  
         [0069]     In step S 103 , the connection controller  14  detects, via the short-distance wireless interface  16 , the mobile terminal  30   a - 2  carried by the user A 2 , and performs authentication processing for the mobile terminal  30   a - 2 . Accordingly, the teleconference terminal  10   a  enters a state in which communication with the mobile terminal  30   a - 2  can be performed.  
         [0070]     In step S 104 , the connection controller  14  waits for a request from the mobile terminal  30   a - 2  for transfer to the session  2 - 2 . If the connection controller  14  accepts the request, the process proceeds to step S 105 . The connection controller  14  receives a transfer request for a communication session, for example, via the short-distance wireless interface  16  or via the LAN  100  using the LAN interface  15 . For example, when the connection controller  14  reports to the mobile terminal  30   a - 2  the IP address of the teleconference processing unit  11  in the authentication processing in step S 103 , the mobile terminal  30   a - 2  is capable of communicating with the teleconference terminal  10   a  by accessing the teleconference terminal  10   a  using the reported IP address via the wireless LAN access point  20   a  and the LAN  100 .  
         [0071]     In step S 105 , the connection controller  14  reports, via the LAN interface  15 , to the teleconference terminal  10   b , which is being currently connected, about interruption of the teleconference. Thus, the teleconference terminal  10   b  reports, by display or the like, to the user B 1  or the like about the interruption of the teleconference.  
         [0072]     In step S 106 , the connection controller  14  causes the teleconference processing unit  11  to terminate the teleconference processing with the teleconference terminal  10   b , and causes the session  1 - 1  to pause.  
         [0073]     In step S 107 , the connection controller  14  is connected to the teleconference terminal  10   c  in the conference room C via the LAN interface  15  to start the session  2 - 2 , and causes the teleconference processing unit  11  to start processing. By the processing described above, the interruption by the session  2 - 2  with the teleconference terminal  10   c  is completed, and the teleconference with the conference room C starts.  
         [0074]     In step S 108 , the connection controller  14  determines whether or not an instruction for disconnecting the communication with the teleconference terminal  10   c , which is currently communicating with the teleconference terminal  10   a , is given. The connection controller  14  is capable of receiving a disconnection instruction, for example, in accordance with operation control input to the input unit  17  by the user A 2  or the like or in accordance with a request signal from the mobile terminal  30   a - 2  via the LAN interface  15  (or the short-distance wireless interface  16 ). If the connection controller  14  receives a disconnection instruction, the process proceeds to step S 201  in  FIG. 9 . If the connection controller  14  does not receive a disconnection instruction, the process proceeds to step S 109 .  
         [0075]     In step S 109 , the connection controller  14  determines whether or not a request for transferring a communication session to the mobile terminal  30   a - 1  of the user A 1  is given. The connection controller  14  receives such a request in accordance with a request signal from the mobile terminal  30   a - 1  via the LAN interface  15  (or the short-distance wireless interface  16 ). Alternatively, the connection controller  14  may receive such a request from the mobile terminal  30   b  of the user B 1  via the teleconference terminal  10   b . Alternatively, the connection controller  14  may receive such a request in accordance with operation control input to the input unit  17  of the teleconference terminal  10   a  by the user. In this case, however, the teleconference terminal  10   a  needs to acknowledge the mobile terminal  30   a - 1  in advance via short-distance wireless communication. If the connection controller  14  receives a transfer request, the process proceeds to step S 301  in  FIG. 10 . If the connection controller  14  does not receive a transfer request, the process proceeds to step S 110 .  
         [0076]     If the connection controller  14  does not receive an instruction in step S 108  and the connection controller  14  does not receive a request in step S 109 , in step S 110 , the connection controller  14  keeps the communication session  2 - 2  with the teleconference terminal  10   c , and at the same time, keeps the communication session  1 - 1  with the teleconference terminal  10   b  by regularly transmitting and receiving, for example, information reporting conditions of the teleconference terminals  10   a  and  10   b , using an IP address stored as history information.  
         [0077]      FIG. 9  is a flowchart of a process performed by the teleconference terminal  10   a  when the original communication session is recovered after the communication is interrupted.  
         [0078]     If the connection controller  14  receives an instruction for disconnecting the communication with the teleconference terminal  10   c , in step S 201 , the connection controller  14  reports, via the LAN interface  15 , to terminals relating to the present session  2 - 2 , that is, the teleconference terminal  10   c  in the conference room C and the mobile terminal  30   a - 2  of the user A 2  (in a case where the teleconference based on the session  2 - 2  started in accordance with session transfer from these terminals) about termination of the teleconference. Thus, each of the terminals reports, by display or the like, to the corresponding user about termination of the teleconference, and the teleconference terminal  10   c  starts termination processing for the teleconference.  
         [0079]     In step S 202 , the connection controller  14  causes the teleconference processing unit  11  to stop the processing with the teleconference terminal  10   c , and disconnects the session  2 - 2  with the teleconference terminal  10   c.    
         [0080]     In step S 203 , the connection controller  14  extracts, from among records, the IP address of the teleconference terminal  10   b  in the conference room B.  
         [0081]     In step S 204 , the connection controller  14  accesses the teleconference terminal  10   b  via the LAN interface  15  using the extracted IP address, and queries-whether or not the teleconference can restart. If a reply indicating that the teleconference can restart is given, the process proceeds to step S 205 . If a reply indicating that the teleconference cannot restart is given, the process proceeds to step S 207 .  
         [0082]     In step S 205 , the connection controller  14  reports, via the LAN interface  15 , to terminals relating to the session  1 - 1 , which is to restart, that is, the teleconference terminal  10   b  and the mobile terminal  30   a - 1  of the user A 1  (in a case where the teleconference based on the session  1 - 1  started in accordance with session transfer from these terminals) about restart of the teleconference. Each of the terminals reports, by display or the like, to the corresponding user about restart of the teleconference.  
         [0083]     In step S 206 , the connection controller  14  restarts the communication session  1 - 1  with the teleconference terminal  10   b , and causes the teleconference processing unit  11  to start image and audio processing. If there is information necessary for connection for restarting the communication, such information is extracted from records and used. In accordance with the processing described above, teleconference processing between the teleconference terminals  10   a  and  10   b  automatically restarts without particularly requiring the user A 1  and B 1  to perform a setting operation for connection.  
         [0084]     If the teleconference cannot be held using the teleconference terminal  10   b , in step S 207 , the connection controller  14  reports, via the LAN interface  15 , to terminals relating to the session  1 - 1 , that is, the teleconference terminal  10   b  and the mobile terminal  30   a - 1  of the user A 1  (in a case where the teleconference based on the session  1 - 1  started in accordance with session transfer from these terminals) that the teleconference cannot restart, and terminates the process.  
         [0085]      FIG. 10  is a flowchart of a process performed by the teleconference terminal  10   a  when the original communication session is transferred to another communication session after communication interruption.  
         [0086]     In step S 301 , if a request for transfer to the session  1 - 2  is given, the connection controller  14  reports, via the LAN interface  15 , to terminals relating to the session  1 - 1 , which is pausing, that is, the teleconference terminal  10   b  and the mobile terminal  30   a - 1  of the user A 1  (in a case where the teleconference based on the session  1 - 1  started in accordance with session transfer from these terminals) that the teleconference does not restart.  
         [0087]     In step S 302 , the connection controller  14  reports, via the LAN interface  15 , to the teleconference terminal  10   b  that the communication session is transferred to the mobile terminal  30   a - 1  of the user A 1 .  
         [0088]     The teleconference terminal  10   b  reports, by display or the like, to the user B 1  reported information or the like, and waits for a reply from the mobile terminal  30   b  of the user B 1 . Then, when the user B 1  brings the mobile terminal  30   b  closer to the teleconference terminal  10   b  and mutual authentication is achieved via short-distance wireless communication, the teleconference terminal  10   b  determines that transfer to the mobile terminal  30   b  can be performed. Then, the teleconference terminal  10   b  reports to the teleconference terminal  10   a  that transfer to the mobile terminal  30   b  can be performed. For example, if the mobile terminal  30   b  cannot be detected over a predetermined period or more or if an operation indicating that transfer cannot be performed is input using the input unit  17 , the teleconference terminal  10   b  reports to the teleconference terminal  10   a  that the communication session cannot be transferred to the mobile terminal  30   b.    
         [0089]     In step S 303 , the connection controller  14  of the teleconference terminal  10   a  determines whether or not the communication session can be transferred to the mobile terminal  30   b  in accordance with a reply signal from the teleconference terminal  10   b . If the communication session can be transferred to the mobile terminal  30   b , the process proceeds to step S 304 . If the communication session cannot be transferred to the mobile terminal  30   b , the process proceeds to step S 306 .  
         [0090]     In step S 304 , the connection controller  14  reports, via the LAN interface  15 , to the mobile terminal  30   a - 1  of the user A 1  that communication with the mobile terminal  30   b  of the user B 1  starts.  
         [0091]     In step S 305 , the connection controller  14  performs transfer processing to the session  1 - 2  between the mobile terminals  30   a - 1  and  30   b . A specific example of this transfer processing will be described later with reference to  FIGS. 11A and 11B .  
         [0092]     If transfer to the mobile terminal  30   b  cannot be performed, in step S 306 , the connection controller  14  reports, via the LAN interface  15 , to the mobile terminal  30   a - 1  of the user A 1  that communication with the teleconference terminal  10   b  in the conference room B starts. Then, the process proceeds to step S 305 , and transfer processing to the session  1 - 2  (however, here, a communication session newly established between the mobile terminal  30   a - 1  and the teleconference terminal  10   b ) is performed.  
         [0093]      FIGS. 11A and 11B  show examples of a process for transfer to a communication session newly established between the mobile terminals  30   a - 1  and  30   b.    
         [0094]     In the example shown in  FIG. 11A , the mobile terminal  30   a - 1  and the teleconference terminal  10   a  detect and authenticate each other in step S 51 , and the mobile terminal  30   b  and the teleconference terminal  10   b  detect and authenticate each other in step S 52 . For example, when the user A 1  brings the mobile terminal  30   a - 1  closer to the teleconference terminal  10   a , the teleconference terminal  10   a  detects the mobile terminal  30   a - 1  via the short-distance wireless interface  16 , receives identification information of the terminal, and performs authentication processing. When authentication is achieved, the teleconference terminal  10   a  reports to the mobile terminal  30   a - 1  identification information, the IP address, and the like of the teleconference terminal  10   a . Accordingly, authentication processing is completed, and the mobile terminal  30   a - 1  enters a state in which the mobile terminal  30   a - 1  can communicate with the teleconference terminal  10   a  via short-distance wireless communication and via the LAN  100 . Similar detection and authentication processing is performed between the mobile terminal  30   b  and the teleconference terminal  10   b , and the mobile terminal  30   b  and the teleconference terminal  10   b  enter a state in which communication between the mobile terminal  30   b  and the teleconference terminal  10   b  can be performed.  
         [0095]     Then, the user A 1  operates the mobile terminal  30   a - 1 , and requires the teleconference terminal  10   a  to transfer the communication session. Here, the mobile terminal  30   a - 1  reports, via the LAN  100  (or via short-distance wireless communication), to the teleconference terminal  10   a  setting information necessary for conversation over the IP telephone service, such as an IP address of the mobile terminal  30   a - 1  (step S 53 ). If information necessary as setting information is reported to the teleconference terminal  10   a  in the processing of step S 51 , only a transfer request may be given without reporting such information in step S 53 . In addition, in practice, when a transfer request from the mobile terminal  30   a - 1  is given, the processing in steps S 301  to S 304  in  FIG. 10  is performed, and then, setting information is reported from the mobile terminal  30   a - 1 .  
         [0096]     The teleconference terminal  10   a  reports to the teleconference terminal  10   b  the reported setting information using the session  1 - 1 , which is pausing, and requires the teleconference terminal  10   b  to transfer the communication session, that is, to be connected to the mobile terminal  30   a - 1  over the IP telephone service (step S 54 ). Connection to the teleconference terminal  10   b  is performed on the basis of a record of setting information stored in the teleconference terminal  10   a . In addition, at that time, the connection controller  14  of the teleconference terminal  10   a  performs message transmission. Thus, the teleconference processing unit  11  is capable of continuing the teleconference processing with the teleconference terminal  10   c.    
         [0097]     In response to the transfer request received from the teleconference terminal  10   a , the teleconference terminal  10   b  reports, via the LAN  100  (or via short-distance wireless communication), to the mobile terminal  30   b  the reported setting information, and requires the mobile terminal  30   b  to be connected to the mobile terminal  30   a - 1  (step S 55 ). The mobile terminal  30   b  originates a call to the mobile terminal  30   a - 1  using the reported setting information, and establishes connection of the session  1 - 2  between the mobile terminals  30   a - 1  and  30   b  over the IP telephone service (step S 56 ).  
         [0098]     In contrast, in the example shown in  FIG. 11B , the session  1 - 2  starts by transmission from the mobile terminal  30   a - 1 . In steps S 61  and S 62 , the mobile terminal  30   a - 1  and the teleconference terminal  10   a  detect and authenticate each other, and the mobile terminal  30   b  and the teleconference terminal  10   b  detect and authenticate each other, as in steps S 51  and S 52  shown in  FIG. 11A . Then, when the user A 1  operates the mobile terminal  30   a - 1  and requires the teleconference terminal  10   a  to transfer the communication session, the processing in steps S 301  to S 304  shown in  FIG. 10  is performed. Then, the teleconference terminal  10   a  requires, using the session  1 - 1 , the teleconference terminal  10   b  to send setting information for connection with the mobile terminal  30   b , which is to be connected to the mobile terminal  30   a - 1  (step S 63 ). The connection to the teleconference terminal  10   b  is performed on the basis of a record of setting information stored in the teleconference terminal  10   a.    
         [0099]     In response to the request from the teleconference terminal  10   a , the teleconference terminal  10   b  accesses the mobile terminal  30   b  via the LAN  100  (or via short-distance wireless communication), requires the mobile terminal  30   b  to send setting information, and acquires the setting information (step S 64 ). If information necessary as setting information is reported to the teleconference terminal  10   b  in the processing of step S 62 , the processing of step S 64  may not be performed. Then, the teleconference terminal  10   b  reports to the teleconference terminal  10   a  the acquired setting information using the session  1 - 1  (step S 65 ).  
         [0100]     The teleconference terminal  10   a  reports, via the LAN  100  (or via short-distance wireless communication), to the mobile terminal  30   a - 1  the setting information received from the teleconference terminal  10   b , and requires the mobile terminal  30   a - 1  to be connected to the mobile terminal  30   b  (step S 66 ). In response to the connection request, the mobile terminal  30   a - 1  originates a call to the mobile terminal  30   b  using the reported setting information. Accordingly, connection based on the session  1 - 2  between the mobile terminals  30   a - 1  and  30   b  over the IP telephone service is established (step S 67 ).  
         [0101]     In accordance with the process described above, in response to the request from the mobile terminal  30   a - 1  to transfer the communication session, setting information, such as the address of the mobile terminal  30   a - 1  or the mobile terminal  30   b , is automatically reported to a call originator of the new session  1 - 2 , and the new communication session starts. Thus, the user A 1  is able to start conversation with the user B 1  by an easy operation without performing a setting operation for connection with the mobile terminal  30   b , such as inputting of a telephone number and an IP address.  
         [0102]     Although the communication session after transfer adopts the IP telephone service in the foregoing process, the communication session does not necessarily adopt the IP telephone service. Any communication service supported by a terminal used in a new session can be adopted.  
         [0103]     As described above, according to the communication service in this embodiment, when a communication session is interrupted by another communication session, processing for recovering the original communication session or for transferring the original communication session to a newly established communication session while the interrupting communication session is maintained can be realized by an easy operation depending on the condition. Thus, the convenience of a user of a communication service, such as a teleconferencing service, can be enhanced.  
         [0104]     It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and alterations may occur depending on design requirements and other factors insofar as they are within the scope of the appended claims or the equivalents thereof.