Communication terminal, communication system, communication method, and program

Abstract

To provide a communication terminal, communication system, communication method, and program, which allow for easily grasping which participants belonged to which group after participants leaves group meetings.SOLUTION: A communication terminal provided herein allows for making voice calls by exchanging voice signals with other communication terminals via a network, and comprises: an acquisition unit configured to acquire participant information of each group meeting from a meeting storage unit having two or more group meetings originating from a plenary meeting registered therein; and a display control unit configured to modify a plenary meeting screen layout to be displayed on a display unit based on the participant information of each group meeting acquired by the acquisition unit in such a way that the screen clearly shows which participants were in which group meeting.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a communication terminal, a communication system, a communication method, and a program. [Background technology]

[0002] Conventionally, companies, educational institutions, government agencies, and the like have used video conferencing systems in which audio signals are input to a microphone and transmitted to other information processing devices, and audio signals and camera images received from the other information processing devices are played back on a speaker and display. Generally, in addition to a general conversation about a single topic, a conference often involves group work (group meetings) in which participants are divided into groups to discuss the topic. Furthermore, the number of participants in a conversation frequently changes, such as when the entire group is reconvened based on the results of the discussion. A mechanism is known that enables a video conferencing system to interrupt a conference midway to allow for group work.

[0003] A system for creating such group work has been disclosed that defines four types of information spaces: classroom type, round table type, self-study type, and a combination of classroom type and round table type, and allows only users within each information space to chat with each other (see Patent Document 1). Summary of the Invention [Problem to be solved by the invention]

[0004] However, the technology described in Patent Document 1 simply divides conference participants into multiple groups and holds the conference. Therefore, when a participant leaves a group conference, the information for each group conference is not collectively managed in the system, which poses a problem in that it is not clear to which group the participant who left the group conference belonged.

[0005] The present invention has been made in consideration of the above, and aims to provide a communication terminal, a communication system, a communication method, and a program that make it easy to determine which group a participant belonged to when that participant leaves a group conference. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems and achieve the object, the present invention provides a communication terminal capable of making calls with other communication terminals by sending and receiving audio signals via a network, characterized in that it comprises: an acquisition unit that acquires participant information for each group conference from a conference memory unit in which information on two or more group conferences derived from a general conference is registered; and a display control unit that changes the layout of the conference screen of the general conference to be displayed on a display unit based on the participant information for each group conference acquired by the acquisition unit so as to clearly indicate which group conference the participant was participating in. [Effects of the Invention]

[0007] According to the present invention, when a participant leaves a group conference, it is possible to easily know which group the participant belonged to. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic configuration diagram of a communication system according to an embodiment. [Figure 2] FIG. 2 is a diagram illustrating an example of a hardware configuration of a communication terminal according to the embodiment. [Figure 3] FIG. 3 is a diagram illustrating an example of a hardware configuration of the management system and the program providing system according to the embodiment. [Figure 4] FIG. 4 is a diagram illustrating an example of a software configuration of the communication terminal according to the embodiment. [Figure 5] FIG. 5 is a diagram illustrating an example of a functional block configuration of the communication system according to the embodiment. [Figure 6]FIG. 6 is a diagram illustrating an example of the authentication management table. [Figure 7] FIG. 7 is a diagram illustrating an example of the terminal management table. [Figure 8] FIG. 8 is a diagram illustrating an example of the conference management table. [Figure 9] FIG. 9 illustrates an example of a session management table. [Figure 10] FIG. 10 is a diagram illustrating an example of the chat management table. [Figure 11] FIG. 11 is a diagram showing sessions established for transmitting and receiving content data and various management information in the communication system according to the embodiment. [Figure 12] FIG. 12 is a sequence diagram showing an example of a preparatory process including an authentication process for a communication terminal to start a call. [Figure 13] FIG. 13 is a diagram showing an example of the destination list screen. [Figure 14] FIG. 14 is a sequence diagram illustrating an example of a process for starting a general conference in the communication system according to the embodiment. [Figure 15] FIG. 15 is a diagram showing an example of the start request dialog box. [Figure 16] FIG. 16 is a diagram showing an example of the conference screen (host) of the general conference. [Figure 17] FIG. 17 is a sequence diagram showing an example of a process for starting a group conference in the communication system according to the embodiment. [Figure 18] FIG. 18 is a diagram showing an example of the group selection screen. [Figure 19] FIG. 19 is a diagram showing an example of a group conference status screen immediately after the start of a group conference. [Figure 20] FIG. 20 is a diagram showing an example of a dialog box for requesting the start of a group conference. [Figure 21] FIG. 21 is a diagram showing an example of the conference screen (host) of a general conference when a specific participant enters the group conference. [Figure 22]FIG. 22 is a diagram showing an example of a group conference status screen when a specific participant has entered the group conference. [Figure 23] FIG. 23 is a diagram showing an example of the conference screen (host) of the general conference when a specific participant also enters the group conference. [Figure 24] FIG. 24 is a diagram showing an example of a group conference status screen when a specific participant also enters the group conference. [Figure 25] FIG. 25 is a sequence diagram showing an example of the operation when a communication terminal (guest) leaves a group conference midway in the communication system according to the embodiment. [Figure 26] FIG. 26 is a diagram showing an example of a group conference status screen when a specific participant leaves the group conference midway. [Figure 27] FIG. 27 is a diagram showing an example of the conference screen (host) of the general conference when a specific participant leaves the group conference midway. [Figure 28] FIG. 28 is a sequence diagram showing an example of the operation when a communication terminal (guest) enters a group conference midway in the communication system according to the embodiment. [Figure 29] FIG. 29 is a sequence diagram showing an example of the operation when a communication terminal (host) enters a group conference midway in the communication system according to the embodiment. [Figure 30] FIG. 30 is a diagram showing an example of the conference screen (guest) of a group conference when the host enters the group conference midway. [Figure 31] FIG. 31 is a sequence diagram showing an example of the operation when a communication terminal (host) leaves a group conference midway in the communication system according to the embodiment. [Figure 32] FIG. 32 is a sequence diagram showing an example of an operation of displaying chat contents on a group conference status screen when a group is selected in the communication system according to the embodiment. [Figure 33] FIG. 33 is a diagram showing an example of the group conference status screen when a specific group is selected. [Figure 34]FIG. 34 is a sequence diagram showing an example of a process for ending a group conference in the communication system according to the embodiment. [Figure 35] FIG. 35 is a diagram showing an example of the group conference status screen when the group conference is ended. [Figure 36] FIG. 36 shows an example of a dialog box for requesting to leave the room, which is displayed when the group conference ends. [Figure 37] FIG. 37 is a sequence diagram showing an example of a deletion process of a group conference status screen in the communication system according to the embodiment. [Figure 38] FIG. 38 is a sequence diagram showing an example of a layout change process of a conference screen of a general conference on the host terminal side in the communication system according to the embodiment. [Figure 39] FIG. 39 is a diagram showing an example of a conference screen of a general conference in which the layout has been changed after the group conference has ended. [Figure 40] FIG. 40 is a diagram showing another example of the conference screen of the general conference in which the layout has been changed after the group conference has ended. [Figure 41] FIG. 41 is a diagram showing another example of the conference screen of the general conference in which the layout has been changed after the group conference has ended. [Figure 42] FIG. 42 is a sequence diagram showing an example of a layout change process of the conference screen of the general conference on the guest terminal side in the communication system according to the embodiment. [Figure 43] FIG. 43 is a diagram illustrating an example of a software configuration when a Web application of the communication terminal according to the embodiment is used. DETAILED DESCRIPTION OF THE INVENTION

[0009] Below, with reference to the drawings, embodiments of a communication terminal, a communication system, a communication method, and a program according to the present invention will be described in detail. Furthermore, the present invention is not limited to the following embodiments, and the components in the following embodiments include those that would be easily conceived by a person skilled in the art, those that are substantially the same, and those that are within the scope of what is called equivalents. Furthermore, various omissions, substitutions, modifications, and combinations of the components can be made without departing from the spirit of the following embodiments.

[0010] Computer software refers to programs related to computer operation and other information used for computer processing that is equivalent to a program (hereinafter, computer software is referred to as software). Application software is a general term for software used to perform specific tasks. Meanwhile, an operating system (OS) is software that controls a computer and enables application software and other computer resources. The operating system performs basic computer management and control, such as input / output control, hardware management such as memory and hard disk, and process management. Application software operates using the functions provided by the operating system. A program is a set of instructions for a computer, combined to achieve a single result. Equivalents to programs are those that are not directly directed to a computer and therefore cannot be called programs, but have properties similar to programs in that they define computer processing. For example, a data structure (the logical structure of data expressed by the interrelationships between data elements) is equivalent to a program.

[0011] (Overall configuration of the communication system) 1 is a schematic diagram of a communication system according to an embodiment, and the configuration of the communication system 1 according to the embodiment will be outlined with reference to FIG.

[0012] As shown in FIG. 1, the communication system 1 includes a plurality of communication terminals 10aa, 10ab, 10ba, 10bb, 10ca, 10cb, 10da, and 10db, displays 120aa, 120bb, 120ca, and 120db for each communication terminal, a management system 50, and a program provision system 90, and is configured to be able to communicate with each other via a communication network 2.

[0013] 1 shows communication terminals 10aa, 10ab, 10ba, 10bb, 10ca, 10cb, 10da, and 10db, but when referring to any of these communication terminals or when referring collectively, they will be simply referred to as "communication terminal 10." Furthermore, the multiple communication terminals 10 included in communication system 1 shown in FIG. 1 are merely an example, and the number of communication terminals 10 may be different.

[0014] 1 shows displays 120aa, 120bb, 120ca, and 120db, but when referring to any of these displays or when referring collectively, they will be simply referred to as "display 120." The multiple displays 120 included in communication system 1 shown in FIG. 1 are merely an example, and the number of displays may vary depending on the number of communication terminals 10.

[0015] Furthermore, the communication terminal 10 may be any of a dedicated device connected to a display (the above-described display 120), a desktop PC (Personal Computer), a notebook PC, a smartphone, a tablet terminal, etc. However, the following description will be given assuming that the communication terminal 10 is a notebook PC.

[0016] A communication terminal 10 is a terminal that transmits and receives various types of information to and from other devices. A communication terminal 10 establishes a session with another communication terminal 10, and in the established session, a call is made by transmitting and receiving content data including audio data and image data (video data). This allows a video conference to be realized among a plurality of communication terminals 10 in the communication system 1. Note that a video conference may also be simply referred to as a "conference."

[0017] The management system 50 is a computer that centrally manages the communication terminals 10. The management system 50 establishes a session between the communication terminals 10, thereby realizing a video conference through calls or the like between the communication terminals 10. When the management system 50 receives a session start request from a specific communication terminal 10, it establishes a session between the communication terminal 10 that sent the start request (start request terminal) and the destination terminal, and starts the video conference. Therefore, the management system 50 relays content data between the multiple communication terminals 10 through the established session. Note that although the management system 50 establishes a session between the multiple communication terminals 10, the actual relay of the content data may be performed by a separate relay device. In this embodiment, for simplicity of explanation, it is assumed that the management system 50 establishes the session and relays the content data.

[0018] The program providing system 90 is a computer that includes an auxiliary storage device (such as an HDD (Hard Disk Drive)) that stores terminal programs for causing the communication terminal 10 to realize various functions or various means, and provides terminal programs (such as communication application A described below) to the communication terminal 10. The program providing system 90 also stores programs in the auxiliary storage device for causing the management system 50, etc. to realize various functions or various means, and can transmit the corresponding programs to the management system 50, etc.

[0019] The communication network 2 is constructed to include, for example, LANs (Local Area Networks) 2a to 2d, dedicated lines 2ab and 2cd, and the Internet 2i, as shown in Fig. 1. Note that the communication network 2 is not limited to the configuration shown in Fig. 1, but may include other network devices, and may include locations where not only wired but also wireless communication is performed.

[0020] The LANs 2a to 2d and the leased lines 2ab and 2cd include routers 70a to 70d, 70ab, and 70cd, respectively. The routers 70a to 70d, 70ab, and 70cd are network devices that select the optimal route for communication data. Note that when referring to any one of the routers 70a to 70d, 70ab, and 70cd or when referring collectively to them, they will be simply referred to as "router 70."

[0021] The communication terminals 10 (10aa, 10ab, ...) and the router 70a are communicatively connected by a LAN 2a. The communication terminals 10 (10ba, 10bb, ...) and the router 70b are communicatively connected by a LAN 2b. The LAN 2a, LAN 2b, and the router 70ab are communicatively connected by a dedicated line 2ab, and are constructed within an area A.

[0022] On the other hand, the communication terminals 10 (10ca, 10cb, ...) and the router 70c are communicatively connected by LAN2c. Furthermore, the communication terminals 10 (10da, 10db, ...) and the router 70d are communicatively connected by LAN2d. Furthermore, LAN2c, LAN2d, and the router 70cd are communicatively connected by a dedicated line 2cd, and are constructed in area B.

[0023] The networks of area A and area B are connected to each other via routers 70ab and 70cd so that they can communicate with each other via the Internet 2i.

[0024] The management system 50 and the program providing system 90 are communicably connected to each communication terminal 10 via the Internet 2i. The management system 50 and the program providing system 90 may be installed in region A or region B, or may be installed in a region other than these.

[0025] 1, the four sets of numbers shown near each communication terminal 10, management system 50, router 70, and program providing system 90 simply represent a typical IPv4 IP (Internet Protocol) address. For example, the IP address of communication terminal 10aa is assumed to be "1.2.1.3." Note that although IPv6 may be used instead of IPv4, for the sake of simplicity, IPv4 will be used in the following description.

[0026] Note that the configuration of the communication system 1 shown in Fig. 1 is an example and is not limited to this configuration. That is, the number of devices and systems shown in Fig. 1 is not limited to the number shown in Fig. 1. Also, Fig. 1 shows a network configuration of two areas, areas A and B, but the networks may be within the same area, or three or more areas may be connected by a network.

[0027] (Hardware configuration of communication terminal) 2 is a diagram illustrating an example of a hardware configuration of a communication terminal according to an embodiment, and details of the hardware configuration of the communication terminal 10 will be described with reference to FIG.

[0028] As shown in FIG. 2, the communication terminal 10 according to this embodiment includes a CPU (Central Processing Unit) 101, a ROM (Read Only Memory) 102, a RAM (Random Access Memory) 103, an auxiliary storage device 105, a media drive 107, and an input device 108.

[0029] The CPU 101 is a computing device that controls the overall operation of the communication terminal 10. The ROM 102 is a non-volatile storage device that stores programs (such as a communication application A described later) for the communication terminal 10. The RAM 103 is a volatile storage device that is used as a work area for the CPU 101.

[0030] Auxiliary storage device 105 is a nonvolatile storage device such as an HDD or SSD (Solid State Drive) that stores various types of data such as image data, audio data, and video data. Media drive 107 is a device that controls reading and writing of data from and to media 106, which is a flash memory or the like, under the control of CPU 101. Media 106 is a storage device that is detachable from communication terminal 10. Note that media 106 is not limited to flash memory, and may be an EEPROM (Electrically Erasable and Programmable ROM) or the like, as long as it is a nonvolatile memory that reads and writes data under the control of CPU 101.

[0031] The input device 108 is a device for inputting various information, such as a mouse or a keyboard, and buttons such as a power button.

[0032] The communication terminal 10 also includes a network I / F 111, an image sensor I / F 113, an audio input / output I / F 116, a display I / F 119, a camera 112, a microphone 114, a speaker 115, and a display 120 (display unit).

[0033] The network I / F 111 is an interface for communicating data using the communication network 2. The network I / F 111 is, for example, a network interface card (NIC) that complies with the transmission control protocol (TCP) / internet protocol (IP).

[0034] The imaging element I / F 113 is an interface for transmitting image data to and from the camera 112, which captures an image of a subject and obtains image data under the control of the CPU 101. The camera 112 includes a lens and a solid-state imaging element that converts light into electric charges to digitize an image (video) of the subject. The camera 112 is connected to the imaging element I / F 113 by a cable 112c. The solid-state imaging element may be a complementary metal oxide semiconductor (CMOS) or a charge coupled device (CCD).

[0035] Audio input / output I / F 116 is an interface that processes input and output of audio signals (audio data) between microphone 114, which inputs audio, and speaker 115, which outputs audio, under the control of CPU 101. Microphone 114 and speaker 115 are connected to audio input / output I / F 116 by cables 114c and 115c, respectively.

[0036] The display I / F 119 is an interface for transmitting image data to the display 120 under the control of the CPU 101. The display 120 is a display device configured with a liquid crystal display or an organic electro-luminescence (EL) display, etc., that displays an image of a subject, operation icons, etc. The display 120 is connected to the display I / F 119 by a cable 120c. The cable 120c may be a cable for analog RGB (VGA) signals, a cable for component video, or a cable for HDMI (registered trademark) (High-Definition Multimedia Interface) or DVI (Digital Video Interactive) signals.

[0037] The above-mentioned CPU 101, ROM 102, RAM 103, auxiliary storage device 105, media drive 107, input device 108, network I / F 111, image sensor I / F 113, audio input / output I / F 116 and display I / F 119 are connected to each other so that they can communicate with each other via bus lines 110 such as an address bus and a data bus.

[0038] The hardware configuration of communication terminal 10 shown in Fig. 2 is an example, and may include components other than those shown in Fig. 2. Furthermore, at least one of camera 112, microphone 114, and speaker 115 may be used as an external device separate from communication terminal 10.

[0039] (Hardware configuration of management systems, etc.) 3 is a diagram showing an example of the hardware configuration of the management system 50 and the program providing system 90 according to the embodiment, with reference to which the hardware configuration of the management system 50 and the program providing system 90 will be described in detail.

[0040] First, the hardware configuration of the management system 50 will be described with reference to Fig. 3. As shown in Fig. 3, the management system 50 includes a CPU 201, a ROM 202, a RAM 203, an auxiliary storage device 205, a media drive 207, a display 208, a network I / F 209, a keyboard 211, a mouse 212, and a DVD (Digital Versatile Disc) drive 214.

[0041] The CPU 201 is a computing device that controls the overall operation of the management system 50. The ROM 202 is a non-volatile storage device that stores programs for the management system 50. The RAM 203 is a volatile storage device that is used as a work area for the CPU 201.

[0042] The auxiliary storage device 205 is a storage device such as an HDD or SSD that stores various data such as an authentication management DB 5001, a terminal management DB 5002, a session management DB 5003, a conference management DB 5004, and a chat management DB 5005, which will be described later. The media drive 207 is a device that controls reading and writing of data from and to the recording medium 206, such as a flash memory, under the control of the CPU 201.

[0043] The display 208 is a display device configured with a liquid crystal display, an organic electroluminescence display, or the like, that displays various information such as a cursor, a menu, a window, characters, or an image. The network I / F 209 is an interface for communicating data using the communication network 2. The network I / F 209 is, for example, a NIC that complies with TCP / IP.

[0044] The keyboard 211 is an input device for selecting letters, numbers, and various instructions, moving the cursor, etc. The mouse 212 is an input device for selecting and executing various instructions, selecting a processing target, moving the cursor, etc.

[0045] The DVD drive 214 is a device that controls reading and writing of data from and to a DVD 213, such as a DVD-ROM or DVD-R (DVD Recordable), which is an example of a removable storage medium. Note that, as other examples of the removable storage medium, the data may be recorded on a computer-readable storage medium, such as a CD-R (Compact Disc Recordable) or a Blu-ray disc, and provided.

[0046] The above-mentioned CPU 201, ROM 202, RAM 203, auxiliary storage device 205, media drive 207, display 208, network I / F 209, keyboard 211, mouse 212 and DVD drive 214 are connected to each other so that they can communicate with each other via bus lines 210 such as an address bus and a data bus.

[0047] The hardware configuration of the management system 50 shown in FIG. 3 is an example, and it is not necessary to include all of the components shown in FIG. 3, or other components may be included.

[0048] Furthermore, the program for the management system 50 described above may be recorded in the form of an installable or executable file on a computer-readable recording medium such as the recording medium 206 or the DVD 213 and distributed.

[0049] Furthermore, the program provision system 90 has a hardware configuration similar to that of the above-described management system 50, and therefore a description thereof will be omitted. However, a program for the program provision system 90, which controls the program provision system 90, is recorded in the ROM 202. In this case as well, the program for the program provision system 90 may be recorded in the form of an installable or executable file on a computer-readable recording medium such as the recording medium 206 or the DVD 213 and distributed.

[0050] (Software configuration of communication terminal) 4 is a diagram showing an example of the software configuration of the communication terminal according to the embodiment, with reference to which the software configuration of the communication terminal 10 will be described in detail.

[0051] A communication application A is installed as a client application in the communication terminal 10. Here, the application means application software. As shown in Fig. 4, an operating system (OS) 1020 and the communication application A run on a working area 1010 in the RAM 103 of the communication terminal 10.

[0052] The OS 1020 is basic software that provides basic functions and manages the entire communication terminal 10. The communication application A operates under the control of the OS 1020 and is an application for communicating (calling) with other communication terminals 10.

[0053] The communication protocol of the communication application A may be Session Initiation Protocol (SIP), H.323, Internet Relay Chat (IRC), or Jingle.

[0054] (Configuration of functional blocks of communication systems) 5 is a diagram showing an example of a functional block configuration of a communication system according to an embodiment. The functional block configuration of a communication system 1 according to this embodiment will be described with reference to FIG.

[0055] <Configuration of functional blocks of communication terminal> As shown in FIG. 5, the communication terminal 10 has a communication unit 11 (acquisition unit, transmission unit), an operation input reception unit 12, an imaging unit 13, a display control unit 14, an audio input unit 15, an audio output unit 16, a memory / readout unit 17, a memory unit 18, and an authentication request unit 19.

[0056] The communication unit 11 is a functional unit that transmits and receives various data to and from other communication terminals 10 or each system via the communication network 2. The communication unit 11 is realized by the execution of a communication application A, which is software, by the CPU 101 shown in FIG. 2 and the network I / F 111.

[0057] Before the communication terminal 10 establishes a session with another communication terminal 10 and starts a video conference via a call, the communication unit 11 starts receiving, from the management system 50, each state information indicating the state of each communication terminal 10 as a candidate destination terminal. Here, the candidate destination terminal is another communication terminal 10 that is a candidate destination used by a user (participant) with whom the communication terminal 10 will hold a video conference, i.e., a person who can be designated as a session partner. In other words, the communication terminal 10 cannot establish a session or hold a video conference with a communication terminal used by a user who is not previously set as a user (participant) who will participate in the video conference.

[0058] The status information indicates the operating status (online or offline status) of each communication terminal 10, and, if online, further indicates a detailed status (hereinafter referred to as a communication status) such as whether the communication terminal is in a call or is on standby. The status information may indicate not only the operating status and communication status of each communication terminal 10, but also various other statuses such as a cable being disconnected from the communication terminal 10, being able to output audio but not an image, or being set not to output audio (MUTE), but the following will explain, as an example, a case where the operating status and communication status are indicated.

[0059] When the communication terminal 10 operates as a start request terminal, the communication unit 11 transmits a conference start request to the management system 50. Here, the conference start request is information requesting the start of a session used for a video conference. Furthermore, the communication unit 11 transmits, together with the conference start request, the terminal ID of the start request terminal that is the sender of the conference start request and the user ID of the participant who is using (logging in to) the communication terminal 10 to the management system 50. The terminal ID is information for identifying the communication terminal 10, and may be stored in advance in the communication terminal 10 or may be determined by the user by directly inputting it into the communication terminal 10. The user ID is information that uniquely identifies a user, and may be freely set by the user or may be an email address used by the user, etc.

[0060] The operation input receiving unit 12 is a functional unit that receives various inputs from the user, and is realized by the input device 108 shown in FIG.

[0061] For example, when a user turns on a power button serving as input device 108 of operation input reception unit 12 shown in Fig. 2, the power of communication terminal 10 is turned on. Also, when a user turns the power from the on state to the off state, communication unit 11 transmits state information to management system 50 indicating that the power of communication terminal 10 has been turned off, and then power of communication terminal 10 is completely turned off. This allows management system 50 to know that communication terminal 10 has changed from a power on state to a power off state.

[0062] The imaging unit 13 is a functional unit that captures an image of a subject and acquires the image data obtained by capturing the image. The imaging unit 13 is realized by the execution of the communication application A by the CPU 101 shown in FIG. 2, the camera 112, and the imaging element I / F 113.

[0063] The display control unit 14 is a functional unit that controls the display of image data and the like on the display 120. The display control unit 14 is realized by the execution of a communication application A by the CPU 101 shown in FIG.

[0064] For example, before the communication terminal 10 as the requester of the video conference starts a video conference call with the communication terminal 10 as the desired destination, the display control unit 14 reflects the status information of the candidate destination terminals received by the communication unit 11 and displays on the display 120 a destination list including the names of each candidate destination terminal and the user IDs of the participants who will use the destination terminal.

[0065] The audio input unit 15 is a functional unit that inputs the audio signal after the voice of the participant (speaker) is converted into an audio signal by the microphone 114. The audio input unit 15 is realized by the execution of the communication application A by the CPU 101 shown in FIG. 2 and the audio input / output I / F 116.

[0066] Audio output unit 16 is a functional unit that outputs an audio signal to speaker 115 and causes audio to be output from speaker 115. Audio output unit 16 is realized by execution of communication application A by CPU 101 shown in FIG. 2 and audio input / output I / F 116.

[0067] The storage / readout unit 17 is a functional unit that stores various data in the storage unit 18 and performs processing to read out various data stored in the storage unit 18. For example, content data received when making a call with a destination terminal is overwritten and stored in the storage unit 18 each time it is received. Of this data, an image is displayed on the display 120 using the image data before being overwritten, and sound is output from the speaker 115 using the audio data before being overwritten. The storage / readout unit 17 is realized by the execution of the communication application A by the CPU 101 shown in FIG. 2.

[0068] The authentication request unit 19 is a functional unit that, when the power of the communication terminal 10 is turned on or when an authentication request operation is accepted by the operation input accepting unit 12, transmits authentication request information indicating a request for login authentication and the current IP address of the communication terminal 10 from the communication unit 11 to the management system 50 via the communication network 2. The authentication request unit 19 is realized by the execution of the communication application A by the CPU 101 shown in FIG.

[0069] At least one of the display control unit 14 and the authentication request unit 19 may be realized by a hardware circuit such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field-Programmable Gate Array).

[0070] Furthermore, the functions of each functional unit of communication terminal 10 shown in Fig. 5 are conceptually shown, and are not limited to such a configuration. For example, the multiple functional units shown as independent functional units in communication terminal 10 shown in Fig. 5 may be configured as a single functional unit. On the other hand, the function of one functional unit of communication terminal 10 shown in Fig. 5 may be divided into multiple functional units and configured as multiple functional units.

[0071] <Configuration of management system function blocks> As shown in Fig. 5, management system 50 includes communication unit 51, authentication unit 52, status management unit 53, extraction unit 54, terminal status acquisition unit 55, session control unit 56, storage / readout unit 57, memory unit 58 (an example of a conference memory unit), conference management unit 59, and chat management unit 60. Memory unit 58 is realized by auxiliary storage device 205 shown in Fig. 3, and as shown in Fig. 5, stores authentication management DB 5001, terminal management DB 5002, session management DB 5003, conference management DB 5004 (an example of a conference memory unit), and chat management DB 5005. Below, each table managed in each DB stored in memory unit 58 will be described.

[0072] <<Authentication Management Table>> FIG. 6 is a diagram illustrating an example of the authentication management table.

[0073] The storage unit 58 stores an authentication management DB 5001 including an authentication management table shown in Fig. 6. In the authentication management table, a password is associated with a user ID that identifies a user (participant) who uses the communication terminal 10 that performs login authentication, and the password is managed in association with the user ID. Here, the password is information used for login authentication. For example, the authentication management table shown in Fig. 6 indicates that the password associated with the user ID "A_10aa" is "aaaa."

[0074] The user ID is identification information such as letters, symbols, numbers, or various marks used to uniquely identify a user who uses the communication terminal 10, and may be, for example, an email address used by the user.

[0075] <<Terminal Management Table>> FIG. 7 is a diagram illustrating an example of the terminal management table.

[0076] The storage unit 58 stores a terminal management DB 5002 including the terminal management table shown in Fig. 7. In the terminal management table, for each terminal ID of each communication terminal 10, the terminal name, the user ID of the user who has logged in to each communication terminal 10, the operating status of each communication terminal 10, the communication status with other communication terminals 10, and the IP address of each communication terminal 10 are associated and managed.

[0077] Here, operating states include "online," which indicates that the power is on and communication is possible or in progress, and "offline," which indicates that communication is not possible, such as when the power is not on. Communication states include, for example, "Calling," "Ringing," "Accepted," "Busy," and "None." "Calling" indicates a state in which another communication terminal 10 is being called, i.e., a state in which a conference start request for establishing a session used for a video conference has been sent to the other communication terminal 10 and a response is being waited for. "Ringing" indicates a state in which another communication terminal 10 is calling, i.e., a state in which a conference start request has been received from the other communication terminal 10 and a response to the received conference start request has not yet been completed. "Accepted" indicates a state in which a permission response has been received in response to the conference start request from the other communication terminal 10 but the establishment of the session has not yet been completed, and a state in which a permission response has been received in response to the conference start request sent by the own terminal but the establishment of the session has not yet been completed. "Busy" indicates a state in which a session with another communication terminal 10 has been established and a call is being made by communicating content data in a video conference. "None" indicates a state in which no communication with another communication terminal 10 has been established and the terminal is on standby.

[0078] For example, in the terminal management table shown in Figure 7, it is shown that the communication terminal 10ad with the terminal ID "10ad" has the terminal name "Japan Tokyo Office AD ​​Terminal", the user ID of the logged-in user is "C_10ad", the operating state is "online", the communication state is "Ringing" indicating that the communication terminal is being called from another communication terminal 10, and the IP address is "1.2.1.6".

[0079] <<Conference Management Table>> FIG. 8 is a diagram illustrating an example of the conference management table.

[0080] The storage unit 58 stores a conference management DB 5004 including the conference management table shown in FIG. 8. For each conference ID identifying a video conference registered in advance in the management system 50, the conference management table associates and manages the original conference ID that identifies the original conference if the video conference is a group conference, the conference name of the video conference, the user IDs of the participants currently participating in the video conference (referred to as "participants"), and the user IDs of the participants who have the right to participate in the video conference (referred to as "participation authority holders"). Note that a group conference refers to a video conference derived from a certain video conference (original conference) in which participants are divided into multiple groups for group work and then held in each group. The original conference before being divided into these group conferences may also be referred to as a "general conference."

[0081] 8, the conference management table shows that a conference with a conference ID of "Conf1-1" has an original conference ID indicating the original conference of "Conf1," a conference name of "Group A," a user ID of a currently participating participant of "B_10ac," and user IDs of participants authorized to participate in the conference of "B_10ac," "C_10ad," and "D_10ae." In this case, it can be seen that the conference identified by this conference ID "Conf1-1" is a group conference separated from the conference (original conference) indicated by the original conference ID "Conf1."

[0082] The subject participating in the conference may be a user (participant) using the communication terminal 10, or may be the communication terminal 10 used by the user. That is, it may be expressed as "a user (participant) participates in the conference" or "the communication terminal 10 participates in the conference."

[0083] <<Session management table>> FIG. 9 illustrates an example of a session management table.

[0084] The storage unit 58 stores a session management DB 5003 including the session management table shown in Fig. 9. In the session management table, for each session ID for identifying a session in which content data is communicated between communication terminals 10, the terminal ID of the terminal that requested the start of the session and the terminal ID of the destination terminal specified as the other party in the conference start request for establishing the session are associated and managed.

[0085] For example, in the session management table shown in Figure 9, the session identified by the session ID "se1" indicates that it has been established between the start request terminal (communication terminal 10aa) with terminal ID "10aa" and the destination terminal (communication terminal 10db) with terminal ID "10db".

[0086] <<Chat management table>> FIG. 10 is a diagram illustrating an example of the chat management table.

[0087] The storage unit 58 stores a chat management DB 5005 including the chat management table shown in Fig. 10. In the chat management table, for each chat ID for identifying a chat generated in a video conference, a conference ID for identifying the conference in which the chat was generated, a user ID of the participant who sent the chat (referred to as "sender"), and chat content, which is the content of the chat, are associated and managed.

[0088] For example, in the chat management table shown in FIG. 10, the chat identified by the chat ID “Chat2” indicates that the generated conference is the conference indicated by the conference ID “Conf1-1”, the sender’s user ID is “B_10ac”, and the content is “thx”.

[0089] The information managed in each table shown in Figures 6 to 10 is in table format, but this is not limited to this and may be managed in a format other than a table as long as the managed information can be associated with each other.

[0090] Returning to FIG. 5, the functional blocks of the management system 50 will be described.

[0091] The communication unit 51 is a functional unit that transmits and receives various data to and from the communication terminal 10 or each system via the communication network 2. The communication unit 51 is realized by the execution of a program by the CPU 201 shown in FIG. 3 and the network I / F 209.

[0092] The authentication unit 52 is a functional unit that performs user authentication by searching the authentication management table (see FIG. 6) in the storage unit 58 using the user ID and password included in the authentication request information received via the communication unit 51 as search keys and determining whether the same user ID and password are managed in the authentication management table. The authentication unit 52 is realized by the execution of a program by the CPU 201 shown in FIG.

[0093] The status management unit 53 is a functional unit that manages the operating status and communication status of the terminal management table shown in Fig. 7. In order to manage the operating status of a communication terminal 10 that has requested login authentication, the status management unit 53 stores and manages the terminal ID of the communication terminal 10, the user ID of the participant logged in to the communication terminal 10, the operating status of the communication terminal 10, and the IP address of the communication terminal 10 in the terminal management table in association with each other.

[0094] When the user of communication terminal 10 operates input device 108 to change the state from off to on, state management unit 53 updates the operation state in the terminal management table from offline to online based on the information to turn the power on sent from communication terminal 10. Furthermore, when the user of communication terminal 10 operates input device 108 to change the state from on to off, state management unit 53 updates the operation state in the terminal management table from online to offline based on the information to turn the power off sent from communication terminal 10.

[0095] The state management unit 53 is realized by the execution of a program by the CPU 201 shown in FIG.

[0096] The extraction unit 54 is a functional unit that searches the conference management table shown in Fig. 8 using the user ID of a participant logged in to a target terminal to be processed, such as the communication terminal 10 that requested login authentication, as a search key, and reads out the user IDs of participants who use candidate destination terminals (communication terminals 10 for calling in the same conference) that can call the target terminal, i.e., can establish a session with the target terminal. The extraction unit 54 is realized by execution of a program by the CPU 201 shown in Fig. 3.

[0097] The terminal status acquisition unit 55 is a functional unit that searches the terminal management table shown in Fig. 7 using the terminal ID as a search key and reads out the operating status and communication status for each terminal ID. This allows the terminal status acquisition unit 55 to acquire the operating status and communication status of candidate destination terminals that can communicate with the communication terminal 10 that has requested login authentication. The terminal status acquisition unit 55 is realized by the execution of a program by the CPU 201 shown in Fig. 3.

[0098] The session control unit 56 is a functional unit that stores and manages the generated session ID, the terminal ID of the start request terminal, and the terminal ID of the destination terminal in association with each other in the session management table shown in Fig. 9. The session control unit 56 performs control for establishing a session between communication terminals 10. The session control unit 56 is realized by the execution of a program by the CPU 201 shown in Fig. 3.

[0099] The storage / readout unit 57 is a functional unit that stores information in various tables in the storage unit 58 and performs processing to read out information from the various tables stored in the storage unit 58. The storage / readout unit 57 is realized by the execution of a program by the CPU 201 shown in FIG.

[0100] The conference management unit 59 is a functional unit that manages the start and end processes of general conferences and group conferences, triggered by the start or end operation of the general conference or group conference by the conference manager (hereinafter sometimes referred to as the "host"). Participants in a general conference other than the manager (host) may be referred to as "guests." The conference management unit 59 updates the participant information in the conference management table shown in FIG. 8 in response to the entry and exit of participants in the general conference and group conference. Here, the participant information specifically refers to the user IDs of participants actually participating in each conference, i.e., the user IDs registered in the "participant" field in the conference management table. The conference management unit 59 is realized by the execution of a program by the CPU 201 shown in FIG. 3.

[0101] The chat management unit 60 is a functional unit that generates a chat ID that uniquely identifies a chat that occurs in a conference, associates the chat ID with the conference ID that indicates the conference, and registers and manages the chat ID in a chat management table. The chat management unit 60 also acquires desired chat content from the chat management table in response to an acquisition request from the communication terminal 10. The chat management unit 60 is realized by the execution of a program by the CPU 201 shown in FIG. 3.

[0102] At least one of the authentication unit 52, the status management unit 53, the extraction unit 54, the terminal status acquisition unit 55, the session control unit 56, the conference management unit 59, and the chat management unit 60 may be realized by a hardware circuit such as an ASIC or FPGA.

[0103] Furthermore, the functional units of the management system 50 shown in Fig. 5 are conceptual representations of functions, and are not limited to such configurations. For example, the multiple functional units illustrated as independent functional units in the management system 50 shown in Fig. 5 may be configured as a single functional unit. On the other hand, the function of one functional unit in the management system 50 shown in Fig. 5 may be divided into multiple units and configured as multiple functional units.

[0104] (Status of sending and receiving content data and various management information) 11 is a diagram showing sessions established for transmitting and receiving content data and various management information in a communication system according to an embodiment. Sessions established for transmitting and receiving content data and various management information in a communication system 1 will be described with reference to FIG.

[0105] 11 shows a state in which a management information session sei is established in communication system 1 between the start request terminal, destination terminal A, and destination terminal B via management system 50 for transmitting and receiving various types of management information. In this case, a content data session sed is also established between the start request terminal, destination terminal A, and destination terminal B via management system 50 for transmitting and receiving image data and audio data. In other words, the content data session sed is a session directly used in video conferencing. Note that this concept of a session is merely an example, and for example, an image data session may be divided by resolution.

[0106] (Transmission and reception of management information in the preparation stage before a communication terminal starts a call) Fig. 12 is a sequence diagram showing an example of a preparatory stage process including an authentication process for a communication terminal to start a call. Fig. 13 is a diagram showing an example of a destination list screen. With reference to Figs. 12 and 13, the transmission and reception process of each piece of information in the preparatory stage before the communication terminal 10aa starts a call will be described. Note that Fig. 12 shows the process of transmitting and receiving various pieces of management information through the management information session sei. Also, it is assumed that a conference group including the communication terminal 10aa, which is the start request terminal, is registered in a conference management table using the conference ID as a key, together with the user IDs of users who have permission to participate in the conference.

[0107] <Step S21> First, when the user of the communication terminal 10aa presses the power button, which is the input device 108 shown in FIG. 2, the operation input accepting unit 12 of the communication terminal 10aa accepts the power-on command and turns on the power of the communication terminal 10aa.

[0108] <Step S22> Then, when the power of the communication terminal 10aa is turned on, the authentication request unit 19 of the communication terminal 10aa transmits authentication request information indicating a login authentication request and the IP address of the communication terminal 10aa from the communication unit 11 via the communication network 2 to the management system 50. This authentication request information includes a terminal ID for identifying the communication terminal 10aa, which is the terminal that has requested the start of communication, and the user ID and password of the user who has logged in to the communication terminal 10aa. The terminal ID, user ID, and password are data that are read from the memory unit 18 by the memory / read unit 17 of the communication terminal 10aa and sent to the communication unit 11. Furthermore, when the authentication request information is transmitted from the communication terminal 10aa to the management system 50, the management system 50, which is the receiving side, can know the IP address of the communication terminal 10aa, which is the transmitting side.

[0109] <Step S23> Next, the authentication unit 52 of the management system 50 searches the authentication management table (see Figure 6) using the user ID and password included in the authentication request information received via the communication unit 51 as search keys, and performs user authentication by determining whether the same user ID and password are managed in the authentication management table.

[0110] <Step S24-1> If the authentication unit 52 determines that the login authentication request is from the communication terminal 10aa used by a user with valid usage rights, the status management unit 53 of the management system 50 stores the user ID and the IP address of the communication terminal 10aa in association with each record indicated by the terminal ID and terminal name of the communication terminal 10aa in the terminal management table (see FIG. 7). As a result, the terminal management table manages the user ID "A_10aa" and the IP address "1.2.1.3" in association with the terminal ID "10aa" of the communication terminal 10aa. Hereinafter, the user (participant) with the user ID "A_10aa" may be referred to as "user A_10aa" or "participant A_10aa."

[0111] <Step S24-2> Next, the status management unit 53 sets the operating status of the communication terminal 10aa to "online" and the communication status to "none," and stores the operating status and the communication status in association with the record indicated by the terminal ID and terminal name of the communication terminal 10aa in the terminal management table. As a result, the operating status "online" and the communication status "none" are managed in association with the terminal ID "10aa" of the communication terminal 10aa in the terminal management table.

[0112] <Step S25> Then, the communication unit 51 of the management system 50 transmits authentication result information indicating the result of the terminal authentication obtained by the authentication unit 52 to the start request terminal (communication terminal 10aa) that transmitted the authentication request information, via the communication network 2. In this embodiment, the case where the authentication unit 52 has authenticated the communication terminal 10aa as a terminal used by a user who has valid use authority will be described below.

[0113] <Step S26> When the communication terminal 10aa receives authentication result information indicating that the terminal is used by a user with valid usage authority, the communication unit 11 transmits destination list request information indicating a request for a destination list to the management system 50 via the communication network 2. As a result, the communication unit 51 of the management system 50 receives the destination list request information.

[0114] <Step S27> Next, the extraction unit 54 of the management system 50 searches the conference management table (see FIG. 8) using the user ID "A_10aa" of the user using the start request terminal (communication terminal 10aa) as a search key, and extracts user IDs (participation authority holders) with whom user A_10aa can talk, i.e., user IDs (participation authority holders) who belong to the same conference as user A_10aa (group with conference ID "Conf1"). The extraction unit 54 also searches the terminal management table using the extracted user ID as a search key, and extracts the terminal ID and terminal name corresponding to this user ID, i.e., the terminal ID and terminal name of candidate destination terminals.

[0115] <Step S28> Next, the communication unit 51 of the management system 50 transmits, to the start request terminal (communication terminal 10aa), destination list information including the user IDs, terminal IDs, and terminal names of the destination terminal candidates extracted by the extraction unit .

[0116] <Step S29> As a result, in the start request terminal (communication terminal 10aa), the communication unit 11 receives the destination list information, and the storage / read unit 17 stores the destination list information in the storage unit 18.

[0117] As described above, in this embodiment, rather than managing the destination list information on each communication terminal 10, the management system 50 centrally manages the destination list information of all communication terminals 10. As a result, even when a new communication terminal 10 is added to the communication system 1 or a communication terminal 10 that is already included is removed, the management system 50 handles this collectively, eliminating the need for each communication terminal 10 to change the destination list information.

[0118] <Step S30> Furthermore, the terminal status acquisition unit 55 of the management system 50 searches the terminal management table using the terminal IDs ("10ac", "10ad", "10ae", "10ba", "10bb", "10cb", "10da") of the destination terminal candidates extracted by the extraction unit 54 as search keys. Then, the terminal status acquisition unit 55 reads out the corresponding operating status and communication status for each terminal ID of the destination terminal candidates, thereby acquiring the operating status and communication status of each of the destination terminal candidates.

[0119] <Step S31> Next, the communication unit 51 transmits terminal status information including the terminal ID, which is the search key used in step S30, the user ID of the corresponding destination terminal candidate, and status information including the operating status and communication status, to the start request terminal via the communication network 2.

[0120] Specifically, the communication unit 51 transmits, to the start request terminal (communication terminal 10aa), terminal status information including, for example, the terminal ID "10ac" as a search key, the user ID "B_10ac" of the destination terminal candidate (communication terminal 10ac), and status information including the operating status "online" and the communication status "none". Note that if the operating status is "offline", the status information does not include the communication status. Furthermore, the communication unit 51 transmits, to the start request terminal (communication terminal 10aa), terminal status information for all destination terminal candidates, such as terminal status information including the terminal ID "10ac", the user ID "B_10ac" of the destination terminal candidate (communication terminal 10ac), and status information including the operating status "online" and the communication status "none".

[0121] <Step S32> Next, the storage / readout unit 17 of the start request terminal (communication terminal 10aa) sequentially stores the terminal status information received from the management system 50 in the storage unit 18. Therefore, by receiving the terminal status information of the candidate destination terminals, the start request terminal (communication terminal 10aa) can obtain the current operating status and communication status of each of the candidate destination terminals with which it can make a call.

[0122] <Step S33> Next, the display control unit 14 of the start requesting terminal (communication terminal 10aa) creates a destination list that reflects the operating status and communication status of the candidate destination terminals, based on the destination list information stored in the storage unit 18 and the terminal status information of the candidate destination terminals. Then, the display control unit 14 displays the destination list on the display 120 of the communication terminal 10aa at a predetermined timing. An example of the displayed destination list is shown in FIG. 13.

[0123] 13, the destination list displayed on the display 120 includes a user ID 1100-1 of a destination terminal candidate, a terminal ID 1100-2 of a destination terminal candidate, a terminal name 1100-3, and icons 1100-4a to 1100-4c reflecting status information. The icons include, for example, an offline icon 1100-4a indicating that a call is not possible offline, a call available icon 1100-4b indicating that a call is possible online, and an in-call icon 1100-4c indicating that a call is in progress online. Note that in the example of the destination list screen shown in FIG. 13, communication terminals 10 with terminal IDs "10ab," "10ac," "10db," and "10ad" are illustrated as destination terminal candidates.

[0124] When the operation status of a destination terminal candidate is "online" and the communication status is "None", the display control unit 14 assigns a call ready icon 1100-4b to this destination terminal candidate. When the operation status of a destination terminal candidate is "online" and the communication status is other than "None", the display control unit 14 assigns a call in progress icon 1100-4c to this destination terminal candidate. When the operation status of a destination terminal candidate is "offline", the display control unit 14 assigns an offline icon 1100-4a to this destination terminal candidate.

[0125] In addition, in the case of another communication terminal 10, similar to step S21, when a user turns on the power button, which is the input device 108 shown in FIG. 2, the operation input receiving unit 12 of that communication terminal 10 receives the on operation, and processing similar to the processing of steps S22 to S33 described above is performed.

[0126] (Start of general meeting) Fig. 14 is a sequence diagram showing an example of a start process of a general conference in the communication system according to the embodiment. Fig. 15 is a diagram showing an example of a start request dialog box. Fig. 16 is a diagram showing an example of a conference screen (host) of a general conference. The start process of a general conference in the communication system 1 according to the present embodiment will be described with reference to Figs. 14 to 16.

[0127] 14 will be described as an example in which the communication terminal 10da, which has been user-authenticated by the authentication process shown in FIG. 12, transmits a conference start request, i.e., an example in which the user using the communication terminal 10da is the host. The communication terminal 10 used by the host may be referred to as a "host terminal," and the communication terminals 10 used by other participants in the general conference managed by the host, i.e., guests, may be referred to as "guest terminals." Based on the terminal status information of the destination terminal candidates received in step S31 of FIG. 12, the host communication terminal 10da can communicate with at least one communication terminal 10 among the destination terminal candidates whose operating status is "online" and whose communication status is "none." The following will be described as an example in which the communication terminal 10ac serving as the destination terminal (guest terminal) receives the conference start request transmitted by the host terminal (communication terminal 10da). It is assumed that, before the process shown in FIG. 14 is started, a destination list screen (see, for example, FIG. 13) is displayed on the display 120 of the communication terminal 10da serving as the host terminal. The host of the host terminal can then select a desired call partner (destination terminal) from the destination list.

[0128] <Step S41> First, the user of communication terminal 10da selects a destination terminal (communication terminal 10ac) to which the start of the conference is to be requested, and starts the conference via input device 108. In this case, communication terminal 10da that has requested the start of the conference is considered to be the host terminal, and the user of communication terminal 10da is the host.

[0129] <Step S42> When an operation to request the start of a conference is performed on the host terminal (communication terminal 10da), the communication unit 11 of the host terminal transmits a conference start request indicating a request to start a conference, along with the host's user ID "H_10da", the participant's user ID "B_10ac" at the destination terminal, and the IP address of the host terminal to the management system 50. As a result, when the communication unit 51 receives the conference start request, the management system 50 learns the IP address "1.3.2.3" of the host terminal that is the sender.

[0130] <Step S43> Then, the status management unit 53 of the management system 50 changes the communication status field of the record in the terminal management table that includes the host user ID "H_10da" and the destination terminal participant user ID "B_10ac" received together with the conference start request. Specifically, the status management unit 53 changes the communication status of the record in the terminal management table that includes the user ID "H_10da" to "Calling." Similarly, the status management unit 53 changes the communication status of the record in the terminal management table that includes the user ID "B_10ac" to "Ringing."

[0131] <Step S44> Then, the session control unit 56 of the management system 50 generates a session ID to identify the session (session sed for content data) for performing communication with the destination terminal requested by the host terminal, and registers it in the session management table of the session management DB 5003.

[0132] <Step S45> Next, the session control unit 56 stores and manages the terminal ID of the host terminal "10da" and the terminal ID of the destination terminal "10ac" in the fields of the terminal ID of the host terminal (the start request terminal in the session management table) and the terminal ID of the destination terminal, respectively, of the record in the session management table that contains the generated session ID.

[0133] <Step S46> Then, the conference management unit 59 of the management system 50 registers the host's user ID "H_10da" in the participant (participant currently participating in the conference) field of a record that includes the host as a participation authority holder in the conference management table of the conference management DB 5004. In addition, the extraction unit 54 of the management system 50 extracts the user IDs of participants other than the host who are registered as participation authority holders of the record from the conference management table.

[0134] <Step S47> Next, the communication unit 51 transmits the session ID generated by the session control unit 56 to the host terminal.

[0135] <Step S48> The communication unit 51 also transmits the host's user ID "H_10da", the session ID, and the IP address of the management system 50 together with the conference start request to the communication terminal 10ac, which is the destination terminal. In practice, the communication unit 51 transmits the conference start request, the host's user ID "H_10da", the session ID, and the IP address of the management system 50 to all communication terminals 10 of the participants identified by the user IDs extracted by the extraction unit 54 in step S46. As a result, the destination terminal receives the conference start request and also learns the IP address "1.1.1.2" of the management system 50.

[0136] <Step S49> When the communication unit 11 of the destination terminal receives the conference start request, the display control unit 14 causes the display 120 to display a start request dialog box 1200-1, as shown in Fig. 15, indicating that the conference start request has been received. The start request dialog box 1200-1 shown in Fig. 15 indicates that the conference start request has been received, and is a user interface for specifying whether or not to permit participation in the conference by starting communication with the host terminal (establishing a session). The user can confirm that the conference start request has been received by viewing the start request dialog box 1200-1. The start request dialog box 1200-1 includes a "Yes" button 1200-2 for permitting participation in the conference, and a "No" button 1200-3 for selecting not to permit participation in the conference.

[0137] <Step S50> When the "Yes" button 1200-2 is pressed by operating the input device 108 of the destination terminal, the operation input receiving unit 12 receives a response indicating that communication with the host terminal will be started (a session will be established) and the destination terminal will participate in the conference.

[0138] <Step S51> Next, the communication unit 11 of the destination terminal transmits to the management system 50 the participant's user ID "B_10ac" of the destination terminal, the host's user ID "H_10da" and the session ID together with a start response indicating participation in the conference.

[0139] <Step S52> When the communication unit 51 receives the start response, the conference management unit 59 of the management system 50 registers the user ID "B_10ac" of the participant at the destination terminal in the participant field of a record that includes the host as a participant (participant currently participating in the conference) in the conference management table of the conference management DB 5004. As a result, the participant at the destination terminal is treated as actually participating in the same conference as the host, the communication terminal 10ac that is the destination terminal functions as a guest terminal, and the participant using the communication terminal 10ac becomes a guest of the conference that they have participated in.

[0140] <Step S53> When the communication unit 51 of the management system 50 receives the start response, the status management unit 53 changes the communication status field of the record in the terminal management table that includes the host user ID "H_10da" and the guest user ID "B_10ac" that were received along with the start response. Specifically, the status management unit 53 changes the communication status of the record in the terminal management table that includes the user ID "H_10da" to "Accepted." Similarly, the status management unit 53 changes the communication status of the record in the terminal management table that includes the user ID "B_10ac" to "Accepted."

[0141] <Step S54> Next, the communication unit 51 transmits the start response, the guest's user ID "B_10ac", and the session ID to the host terminal.

[0142] <Steps S55 and S56> When the host terminal receives this start response, it establishes a session by transmitting a session ID to the management system 50 via the communication unit 11. On the other hand, the guest terminal establishes a session by transmitting a session ID to the management system 50 via the communication unit 11. When a session is established between the host terminal and the guest terminal in this manner, the display control unit 14 of the host terminal displays, for example, a conference screen 1300H shown in FIG. 16 on the display 120. The display control unit 14 of the guest terminal also displays a screen similar to the conference screen 1300H (a conference screen 1600G, described later) on the display 120.

[0143] The conference screen 1300H shown in Fig. 16 includes a participant video 1300H-1, which is a video of a participant (guest) actually participating in a conference hosted by a participant with user ID "H_10da," a self-video 1300H-2, which is a video of the participant (host), a group conference start button 1300H-3, and a conference exit button 1300H-4 for exiting the conference (general conference). The example shown in Fig. 16 shows a state in which participants with user IDs "A_10aa," "B_10ac," "C_10ad," "D_10ae," "E_10ba," "F_10bb," and "G_10cb" are actually participating in the conference as guests. Details of the operation when the group conference start button 1300H-3 is pressed will be described later with reference to Fig. 17, etc.

[0144] <Steps S57 to S60> Once a session is established between the host terminal and the guest terminal in steps S55 and S56, video data and audio data are sent and received between them via the management system 50, enabling a video conference for the entire conference including the host terminal and each guest terminal.

[0145] (Group conference start process) FIG. 17 is a sequence diagram showing an example of a group conference start process in the communication system according to the embodiment. FIG. 18 is a diagram showing an example of a group selection screen. FIG. 19 is a diagram showing an example of a group conference status screen immediately after the start of the group conference. FIG. 20 is a diagram showing an example of a group conference start request dialog box. FIG. 21 is a diagram showing an example of a conference screen (host) of a general conference when a specific participant has joined the group conference. FIG. 22 is a diagram showing an example of a group conference status screen when a specific participant has joined the group conference. FIG. 23 is a diagram showing an example of a conference screen (host) of a general conference when a specific participant has also joined the group conference. FIG. 24 is a diagram showing an example of a group conference status screen when a specific participant has also joined the group conference. The group conference start process in the communication system 1 according to the embodiment will be described with reference to FIGS. 17 to 24. The following describes a case where the communication terminal 10ac, as a guest terminal, receives a group conference start request transmitted by the host terminal (communication terminal 10da).

[0146] <Steps S71 and S72> First, the host of the host terminal (communication terminal 10da) presses the group conference start button 1300H-3 to start the group conference via the input device 108 on the conference screen 1300H shown in Fig. 16. Then, the communication unit 11 of the host terminal transmits to the management system 50 a conference participant acquisition request to request acquisition of participant information of guests currently participating in the conference (general conference) in which the host is participating.

[0147] <Steps S73 and S74> When the communication unit 51 of the management system 50 receives the conference participant acquisition request, the conference management unit 59 acquires participant information (user IDs) of guests currently participating in the conference from the "Participants" field of the record of the conference in which the host is currently participating in the conference management table of the conference management DB 5004. Then, the conference management unit 59 transmits the acquired participant information (guest user IDs) to the host terminal.

[0148] <Step S75> When the communication unit 11 of the host terminal receives the conference participant information (guest user IDs), the display control unit 14 causes the display 120 to display a group selection screen 1400H for assigning a group to each guest, as shown in FIG. 18.

[0149] The group selection screen 1400H shown in FIG. 18 includes a group selection pull-down 1400H-1, a random sorting button 1400H-2, an add group button 1400H-3, an OK button 1400H-4, and a group display section 1400H-5.

[0150] The group selection pull-down 1400H-1 is a pull-down for assigning each guest to one of the groups added using the group addition button 1400H-3.

[0151] The random allocation button 1400H-2 is a button for randomly allocating each guest to one of the set groups.

[0152] The add group button 1400H-3 is a button for setting and adding a new group. The group display section 1400H-5 is an area for displaying the name of the group set and added using the add group button 1400H-3. In the example shown in Fig. 18, two groups, groups a and b, have been set.

[0153] The OK button 1400H-4 is a button for starting a group conference after each guest has been assigned to one of the groups.

[0154] <Step S76> The host performs a selection operation on the group selection screen 1400H via the input device 108 to assign each guest to one of the groups. In the example shown in Fig. 18, participants B_10ac, C_10ad, and D_10ae are assigned to group a, and participants A_10aa, E_10ba, F_10bb, and G_10cb are assigned to group b.

[0155] <Step S77> Then, when the host presses the OK button 1400H-4 via the input device 108, the communication unit 11 of the host terminal transmits to the management system 50 a group conference start request indicating a request to start a group conference, along with participant information (including each guest's user ID) indicating which group each guest is assigned to.

[0156] <Step S78> When the communication unit 51 of the management system 50 receives a group conference start request, the conference management unit 59 generates a conference ID that identifies each group conference indicated by the participant information. For example, the conference management unit 59 generates a conference ID "Conf1-1" for group a and a conference ID "Conf1-2" for group b.

[0157] <Step S79> For each conference ID of each generated group conference, the conference management unit 59 adds and registers a new record in the conference management table, associating the original conference ID (here, "Conf1") that identifies the original conference of the group conference, the conference name of the group conference, and the participation authority holder for the group conference. Specifically, the user ID of the guest assigned to each group in step S76 is registered as the participant authority holder of the new record. At this point, the "Participant" field in the record is empty because there are no guests currently participating in the group conference.

[0158] <Steps S80 and S81> The communication unit 51 transmits to the host terminal a conference ID that identifies each group conference generated by the conference management unit 59. This allows the host terminal to manage each group conference using the received conference ID. When the communication unit 11 of the host terminal receives the conference ID, the display control unit 14 causes the display 120 to display a group conference status screen 1500H (status screen) that indicates the participation status of guests in each group conference, as shown in FIG.

[0159] The group conference status screen 1500H shown in FIG. 19 includes a group a status display section 1500H-1, a group b status display section 1500H-2, a group a selection button 1500H-3, a group b selection button 1500H-4, a group participation authority holder display section 1500H-5, a chat display section 1500H-6, a mute button 1500H-7, an enter button 1500H-8, and an end group conference button 1500H-9.

[0160] The group a status display section 1500H-1 is an area that displays the status of participants who have joined (entered) group a. The group b status display section 1500H-2 is an area that displays the status of participants who have joined (entered) group b. Note that this is an example in which two groups are set, but it is naturally assumed that three or more groups may be set, so the layout of the group status display section may be set appropriately depending on the number of groups set.

[0161] The group a selection button 1500H-3 is a button for selecting group a, a button for causing the audio output unit 16 of the host terminal to output the audio of the group conference of group a, and a button for displaying the chat content generated in the group conference of group a in the chat display unit 1500H-6. The group b selection button 1500H-4 is a button for selecting group b, a button for causing the audio output unit 16 of the host terminal to output the audio of the group conference of group b, and a button for displaying the chat content generated in the group conference of group b in the chat display unit 1500H-6. The example shown in FIG. 19 shows a state in which group a has been selected. Note that the specific details of the operation when the group a selection button 1500H-3 or the group b selection button 1500H-4 is pressed will be described later with reference to FIG. 32, etc.

[0162] The group participation authority holder display section 1500H-5 is an area that displays the user IDs of guests who belong to the selected group (participation authority holders of the group). By pressing the group a selection button 1500H-3 or the group b selection button 1500H-4, the display content of the group participation authority holder display section 1500H-5 switches to display the user IDs of the guests of the selected group.

[0163] The chat display area 1500H-6 is an area that displays the contents of the chat generated in the group conference of the selected group. By pressing the group a selection button 1500H-3 or the group b selection button 1500H-4, the display contents of the chat display area 1500H-6 are switched to the contents of the chat generated in the group conference of the selected group.

[0164] The mute button 1500H-7 is a button for muting the audio output of the group conference by the audio output unit 16. When the mute button 1500H-7 is pressed in the muted state, the muted state is canceled and the audio output unit 16 resumes outputting the audio of the group conference.

[0165] The entry button 1500H-8 is a button for the host to participate (enter) in the group conference of the selected group. Details of the operation of the host participating (entering) in the group conference by pressing the entry button 1500H-8 will be described later with reference to FIG. 29 etc.

[0166] The group conference end button 1500H-9 is a button for ending the group conference currently being held. Details of the group conference ending operation by pressing the group conference end button 1500H-9 will be described later with reference to FIG.

[0167] <Step S82> When the conference management unit 59 of the management system 50 registers information about each group conference in the conference management table, the communication unit 51 transmits the conference ID of each group conference generated by the conference management unit 59 in step S78 to the guest terminal together with a group conference start request. In practice, the communication unit 51 transmits the group conference start request and the conference ID of each group conference to all guest terminals assigned to each group in step S76.

[0168] <Step S83> When the communication unit 11 of the guest terminal receives the group conference start request, the display control unit 14 displays a start request dialog box 1600G-1 indicating that the group conference start request has been received on the conference screen 1600G displayed on the display 120 of the guest terminal, as shown in FIG. 20. The start request dialog box 1600G-1 shown in FIG. 20 indicates that the group conference start request has been received and is a user interface for specifying whether or not to permit participation (entry) in the group conference. The user can confirm that the group conference start request has been received by viewing the start request dialog box 1600G-1. The start request dialog box 1600G-1 includes a "Yes" button 1600G-2 for permitting participation (entry) in the group conference and a "No" button 1600G-3 for selecting not to permit participation in the group conference.

[0169] 20 includes a self-video image 1600G-4 that is an image of the guest using the guest terminal, and an exit button 1600G-5 for exiting the group conference. Details of the operation when leaving the group conference by pressing the exit button 1600G-5 will be described later with reference to FIG. 25 etc.

[0170] <Step S84> When the "Yes" button 1600G-2 is pressed by operating the input device 108 of the guest terminal, the operation input receiving unit 12 receives a response indicating that the guest will participate in the group conference.

[0171] <Step S85> Next, the communication unit 11 of the guest terminal transmits to the management system 50 the user ID "B_10ac" of the guest of the guest terminal together with a start response indicating participation in the group conference.

[0172] <Step S86> When the communication unit 51 receives the start response, the conference management unit 59 of the management system 50 registers the user ID "B_10ac" of the guest in the participant field of the record of the group conference to which the guest of the guest terminal that sent the start response belongs in the conference management table of the conference management DB 5004. Furthermore, the conference management unit 59 deletes the user ID "B_10ac" of the guest from the participant field of the record of the original conference (general conference) indicated by the original conference ID of the record indicating the group conference. As a result, the participant (guest) of the guest terminal is treated as having left the general conference and participated in the group conference.

[0173] <Step S87> The communication unit 51 of the management system 50 transmits the participant information (such as the guest user ID) of the guest terminal that transmitted the start response to the host terminal.

[0174] <Step S88> When the communication unit 11 of the host terminal receives the participant information, the display control unit 14 deletes the video of the guest identified by the user ID included in the participant information from the conference screen 1300H showing the state of the general conference, and updates it, as shown in Fig. 21. The example of the conference screen 1300H shown in Fig. 21 shows a state in which the participant video 1300H-1 showing the participant B_10ac, who is a guest, has been deleted because the participant B_10ac joined the group conference in step S86.

[0175] 22, the display control unit 14 displays and updates a participant video 1500H-1a, which is a video of a guest identified by the user ID included in the participant information received by the communication unit 11, in the group a status display unit 1500H-1 of the group conference status screen 1500H. The display control unit 14 also displays a chat message indicating that the guest has participated in the group conference in the chat display unit 1500H-6. In the example of the group conference status screen 1500H shown in FIG. 22, since guest participant B_10ac participated in the group conference in step S86, participant video 1500H-1a indicating participant B_10ac is added, and a chat message indicating that participant B_10ac has participated is displayed in the chat display unit 1500H-6.

[0176] 22 displays images of the participants who participated in each group conference, but the present invention is not limited to this and any information indicating the participants who participated in each group conference may be displayed. For example, in the case of a participant who participated in the group conference of group a, the group a status display section 1500H-1 may display a still image, user ID, user name, or the like of the participant as information indicating the participant who participated in the group conference of group a.

[0177] Similarly, in the same procedure as steps S83 to S88 described above, when guest participant C_10ad joins the group conference of group a, the state of the conference screen 1300H updated on the host terminal is shown in Fig. 23, and the state of the updated group conference status screen 1500H is shown in Fig. 24. As shown in Fig. 23, the video of participant C_10ad is deleted from the state of the conference screen 1300H shown in Fig. 21, and the screen is updated. Also, as shown in Fig. 24, the group conference status screen 1500H shown in Fig. 22 is updated by adding a display of participant video 1500H-1b, which is the video of participant C_10ad.

[0178] <Step S89> Furthermore, the communication unit 51 of the management system 50 transmits participant information (such as the guest user ID) of the guest terminal that transmitted the start response to the guest terminal itself, thereby enabling the guest terminal to recognize that the management system 50 has properly processed the guest's participation in the group conference.

[0179] <Step S90> When the communication unit 11 of the guest terminal receives the participant information, the display control unit 14 transitions the conference screen 1600G displayed on the display 120 to a screen for the group conference. Specifically, the display control unit 14 updates the conference screen 1600G, which has previously displayed the status of the general conference (displaying the participants participating in the general conference), to a state that displays the status of the group conference. That is, on the guest terminal of participant B_10ac, the display control unit 14 displays an image of participant B_10ac himself on the conference screen 1600G.

[0180] <Steps S91 and S92> When a guest at a guest terminal joins a group conference, the communication unit 11 of the host terminal becomes able to receive video data and audio data for the group conference, the display control unit 14 of the host terminal displays the video of the guest participating in the group conference on the group conference status screen 1500H, and the audio output unit 16 outputs the audio spoken by the guest participating in the group conference.

[0181] As described above, when a guest terminal joins a group conference in response to a group conference start request sent from the host terminal, the voice, chat content, and participating guests for each group conference can be checked on the group conference status screen 1500H displayed on the host terminal. Therefore, the host can check the progress of each group conference without having to attend each group conference one by one.

[0182] (Behavior when a guest leaves a group meeting) FIG. 25 is a sequence diagram showing an example of the operation when a communication terminal (guest) leaves a group conference midway in the communication system according to the embodiment. FIG. 26 is a diagram showing an example of a group conference status screen when a specific participant leaves the group conference midway. FIG. 27 is a diagram showing an example of a conference screen (host) of a general conference when a specific participant leaves the group conference midway. With reference to FIGS. 25 to 27, the operation when a guest leaves a group conference midway in the communication system 1 according to the present embodiment will be described. In the following description, it is assumed that the host terminal is the communication terminal 10da and the guest terminal is the communication terminal 10ac.

[0183] <Steps S101 and S102> First, the guest of the guest terminal (communication terminal 10ac) presses the leave button 1600G-5 to leave the group conference via the input device 108 on the conference screen 1600G shown in Fig. 20. Then, the communication unit 11 of the guest terminal transmits a group conference leave request to the management system 50 to request the guest to leave the group conference in which he or she is participating.

[0184] <Step S103> When the communication unit 51 receives the group conference exit request, the conference management unit 59 of the management system 50 deletes the user ID "B_10ac" of the guest at the guest terminal from the participant field of the record indicating the group conference in which the guest at the guest terminal is participating, in the conference management table of the conference management DB 5004. Furthermore, the conference management unit 59 adds the user ID "B_10ac" of the guest to the participant field of the record of the original conference (general conference) indicated by the original conference ID of the record indicating the group conference. In other words, this process indicates that the guest at the guest terminal leaves the group conference and moves (enters) to the original conference (general conference).

[0185] <Step S104> Furthermore, the conference management unit 59 acquires all user IDs registered in the participant field of the record of the original conference (general conference) of the group conference from which the guest has left, in the conference management table of the conference management DB 5004.

[0186] <Step S105> Then, the communication unit 51 transmits the participant information (such as the user ID of the guest) of the guest who has left the group conference to the host terminal (communication terminal 10da).

[0187] <Step S106> When the communication unit 11 of the host terminal receives the participant information, the display control unit 14 deletes and updates the video of the guest identified by the user ID included in the participant information received by the communication unit 11 in the group a status display unit 1500H-1 of the group conference status screen 1500H, as shown in Fig. 26. The display control unit 14 also displays a chat message indicating that the guest has left the group conference in the chat display unit 1500H-6. In the example of the group conference status screen 1500H shown in Fig. 26, since the guest participant B_10ac left the group conference in step S103, the participant video 1500H-1a indicating participant B_10ac is deleted, and a chat message indicating that participant B_10ac has left is displayed in the chat display unit 1500H-6.

[0188] Then, the display control unit 14 adds and updates the video of the guest identified by the user ID included in the participant information on a conference screen 1300H showing the state of the general conference, as shown in Fig. 27. The example of the conference screen 1300H shown in Fig. 27 shows a state in which participant video 1300H-1 indicating participant B_10ac has been added because the guest participant B_10ac left the group conference in step S103.

[0189] <Step S107> The communication unit 51 transmits the participant information (user IDs of the participants, etc.) of the original conference (general conference) acquired in step S104 to the guest terminal.

[0190] <Step S108> When the communication unit 11 of the guest terminal receives the participant information, the display control unit 14 transitions the conference screen 1600G displayed on the display 120 to the screen of the original conference (general conference). Specifically, the display control unit 14 updates the conference screen 1600G, which had previously displayed the status of the group conference (displaying the participants participating in the group conference), to a state that displays the original conference. That is, in the guest terminal of participant B_10ac, the display control unit 14 displays, on the conference screen 1600G, images of participants (including the guest himself) identified by the user IDs included in the participant information received by the communication unit 11.

[0191] As described above, even if a guest joins (enters) a group conference in response to a request to start a group conference from the host terminal, the guest can individually leave the group conference and return to the original conference (general conference), where they can converse with participants in the original conference. This improves the usability of video conferencing in communication system 1.

[0192] (Behavior when a guest joins a group meeting midway) 28 is a sequence diagram showing an example of the operation when a communication terminal (guest) enters a group conference midway in the communication system according to the embodiment. With reference to FIG. 28, the operation when a guest enters a group conference midway in the communication system 1 according to the present embodiment will be described. In the following, the host terminal is assumed to be the communication terminal 10da, and the guest terminal is assumed to be the communication terminal 10ac.

[0193] <Steps S121 and S122> First, a guest at a guest terminal (communication terminal 10ac) presses a button for mid-entry (re-entry) into a group conference via the input device 108 on the conference screen 1600G shown in FIG. 20 above. In this case, for example, the notation on the exit button 1600G-5 may be changed from "Exit Group Conference" when the guest is participating in the group conference to "Enter Group Conference" once the guest has left the group conference so that the guest can re-enter. In this case, the guest presses the exit button 1600G-5 labeled "Enter Group Conference" on the conference screen 1600G. Then, the communication unit 11 of the guest terminal transmits a group conference entry request to the management system 50 to request entry into the group conference (effectively re-entry) from the general conference in which the guest is participating.

[0194] <Step S123> When the communication unit 51 receives the group conference entry request, the conference management unit 59 of the management system 50 deletes the user ID "B_10ac" of the guest at the guest terminal from the participant field of the record indicating the general conference in which the guest at the guest terminal is participating, in the conference management table of the conference management DB 5004. Furthermore, the conference management unit 59 adds the user ID "B_10ac" of the guest to the participant field of the record of the group conference that includes the conference ID of the general conference as the original conference ID. In other words, this process indicates that the guest at the guest terminal leaves the general conference and moves (re-enters) to the group conference.

[0195] <Step S124> Furthermore, the conference management unit 59 acquires all user IDs registered in the participant field of the record of the group conference to which the guest has joined in the conference management table of the conference management DB 5004.

[0196] <Step S125> Then, the communication unit 51 transmits participant information (such as the guest's user ID) of the guest who has entered the group conference to the host terminal (communication terminal 10da).

[0197] <Step S126> When the communication unit 11 of the host terminal receives the participant information, the display control unit 14 updates the group a status display unit 1500H-1 of the group conference status screen 1500H by adding an image of the guest identified by the user ID included in the participant information received by the communication unit 11. The display control unit 14 also causes the chat display unit 1500H-6 to display a chat message indicating that the guest has entered the group conference.

[0198] Then, the display control unit 14 deletes and updates the video of the guest identified by the user ID included in the participant information on the conference screen 1300H that shows the state of the general conference.

[0199] <Step S127> The communication unit 51 transmits the participant information (user IDs of the participants, etc.) of the group conference acquired in step S124 to the guest terminal.

[0200] <Step S128> When the communication unit 11 of the guest terminal receives the participant information, the display control unit 14 transitions the conference screen 1600G displayed on the display 120 to a screen for the group conference. Specifically, the display control unit 14 updates the conference screen 1600G, which has previously displayed the status of the general conference (displaying the participants participating in the general conference), to a state that displays the status of the group conference. That is, in the guest terminal of participant B_10ac, the display control unit 14 displays, on the conference screen 1600G, images of participants (including the guest himself) identified by the user IDs included in the participant information received by the communication unit 11.

[0201] <Steps S129 and S130> When a guest at a guest terminal re-enters the group conference, the communication unit 11 of the host terminal becomes able to receive the video data and audio data of the group conference, the display control unit 14 of the host terminal displays the video of the guest participating in the group conference on the group conference status screen 1500H, and the audio output unit 16 outputs the audio spoken by the guest participating in the group conference.

[0202] As described above, a guest can join (enter) a group conference in response to a group conference start request from the host terminal, and then individually leave the group conference, and then rejoin the group conference. In other words, even if a guest has joined a group conference once, they can freely move back and forth between the group conference and the general conference as needed. This further improves the usability of video conferencing in the communication system 1.

[0203] (Behavior when the host joins a group meeting midway) Fig. 29 is a sequence diagram showing an example of the operation when a communication terminal (host) enters a group conference midway in a communication system according to an embodiment. Fig. 30 is a diagram showing an example of a conference screen (guest) of a group conference when a host enters a group conference midway. With reference to Figs. 29 and 30, the operation when a host enters a group conference midway in the communication system 1 according to this embodiment will be described. In the following, it is assumed that the host terminal is the communication terminal 10da and the guest terminal is the communication terminal 10ac.

[0204] <Steps S141 and S142> First, the host of the host terminal (communication terminal 10da) presses the enter button 1500H-8 for entering a group conference midway through the group conference status screen 1500H shown in FIG. 24 etc., via the input device 108. Here, it is assumed that group a is selected on the group conference status screen 1500H. Then, the communication unit 11 of the host terminal transmits a group conference entry request to the management system 50 from the general conference in which the host is participating, requesting entry into the selected group conference.

[0205] <Step S143> When the communication unit 51 receives the group conference entry request, the conference management unit 59 of the management system 50 deletes the user ID "H_10da" of the host from the participant field of the record indicating the general conference in which the host of the host terminal is participating, in the conference management table of the conference management DB 5004. Furthermore, the conference management unit 59 adds the user ID "H_10da" of the host to the participant field of the record of the group conference selected by the host terminal. In other words, this process indicates that the host of the host terminal leaves the general conference and moves to the group conference.

[0206] <Step S144> Furthermore, the conference management unit 59 acquires all user IDs registered in the participant field of the record of the group conference to which the host has joined in the conference management table of the conference management DB 5004.

[0207] <Step S145> The communication unit 51 transmits the participant information (user IDs of the participants, etc.) of the group conference acquired in step S144 to the host terminal.

[0208] <Step S146> When the communication unit 11 of the host terminal receives the participant information, the display control unit 14 transitions the conference screen 1300H displayed on the display 120 to a screen for the group conference. Specifically, the display control unit 14 updates the conference screen 1300H, which has previously displayed the status of the general conference (displaying the participants participating in the general conference), to a state that displays the status of the group conference. That is, in the host terminal of participant H_10da, the display control unit 14 displays, on the conference screen 1300H, images of participants (including the host himself) identified by the user IDs included in the participant information received by the communication unit 11.

[0209] The display control unit 14 also updates the group a status display unit 1500H-1 of the group conference status screen 1500H by adding an image of the host identified by the user ID included in the participant information received by the communication unit 11. The display control unit 14 also causes the chat display unit 1500H-6 to display a chat message indicating that the host has entered the group conference.

[0210] <Step S147> The communication unit 51 transmits participant information (such as the host's user ID) of the host who has entered the group conference to the guest terminal (communication terminal 10ac).

[0211] <Step S148> When the communication unit 11 of the guest terminal receives the participant information, the display control unit 14 adds and updates a video of the host identified by the user ID included in the participant information on a conference screen 1600G showing the status of the group conference, as shown in Fig. 30. In the example of the conference screen 1600G shown in Fig. 30, participant H_10da, who is the host, entered the group conference in step S143, and therefore participant video 1600G-6 indicating participant H_10da has been added.

[0212] As described above, the host of the host terminal can enter the selected group conference and can communicate with other participants in the group conference. This allows the host to not only check the status of each group conference on the group conference status screen 1500H, but also to check the progress of the group conference by directly communicating with participants (guests) participating in the group conference.

[0213] (Behavior when the host leaves a group meeting) 31 is a sequence diagram showing an example of the operation when a communication terminal (host) leaves a group conference midway in the communication system according to the embodiment. With reference to FIG. 31, the operation when a host leaves a group conference midway in the communication system 1 according to the embodiment will be described. In the following, the host terminal is assumed to be the communication terminal 10da, and the guest terminal is assumed to be the communication terminal 10ac.

[0214] <Steps S161 and S162> First, the host of the host terminal (communication terminal 10da) presses a button to leave the group conference via the input device 108 on the group conference status screen 1500H shown in FIG. 22 and other figures. In this case, for example, the entry button 1500H-8 may be configured to read "Enter selected group conference" when the host is not participating in the group conference, but to read "Leave selected group conference" when the host has joined the group conference, allowing the host to leave. In this case, the host presses the entry button 1500H-8 labeled "Leave selected group conference" on the group conference status screen 1500H. Then, the communication unit 11 of the host terminal transmits a group conference exit request to the management system 50, requesting the host to leave the group conference in which the host is participating.

[0215] <Step S163> When the communication unit 51 receives the group conference exit request, the conference management unit 59 of the management system 50 deletes the host's user ID "H_10da" from the participant field of the record indicating the group conference in which the host is participating, in the conference management table of the conference management DB 5004. Furthermore, the conference management unit 59 adds the host's user ID "H"_10da" to the participant field of the record of the original conference (general conference) indicated by the original conference ID of the record indicating the group conference. In other words, this process indicates that the host of the host terminal leaves the group conference and moves (enters) to the original conference (general conference).

[0216] <Step S164> Furthermore, the conference management unit 59 acquires all user IDs registered in the participant field of the record of the original conference (general conference) of the group conference from which the host left, in the conference management table of the conference management DB 5004.

[0217] <Step S165> The communication unit 51 transmits the participant information (user IDs of the participants, etc.) of the original conference (general conference) acquired in step S164 to the host terminal.

[0218] <Step S166> When the communication unit 11 of the host terminal receives the participant information, the display control unit 14 transitions the conference screen 1300H displayed on the display 120 to the screen of the original conference (general conference). Specifically, the display control unit 14 updates the conference screen 1300H, which had previously displayed the status of the group conference (displaying the participants participating in the group conference), to a state that displays the original conference. That is, in the host terminal of participant H_10da, who is the host, the display control unit 14 displays, on the conference screen 1300H, images of participants (including the host himself) identified by user IDs included in the participant information received by the communication unit 11.

[0219] The display control unit 14 also deletes the video of the host himself / herself from the group a status display section 1500H-1 of the group conference status screen 1500H and updates it. The display control unit 14 also causes the chat display section 1500H-6 to display a chat message indicating that the host has left the group conference.

[0220] <Step S167> The communication unit 51 transmits participant information (such as the user ID of the host) of the host who has left the group conference to the guest terminal (communication terminal 10ac).

[0221] <Step S168> When the communication unit 11 of the guest terminal receives the participant information, the display control unit 14 updates the conference screen 1600G showing the status of the group conference by deleting the image of the host identified by the user ID included in the participant information.

[0222] (Chat content registration and display on the group meeting status screen) Fig. 32 is a sequence diagram showing an example of the operation of displaying chat content on the group conference status screen when a group is selected in the communication system according to the embodiment. Fig. 33 is a diagram showing an example of the group conference status screen when a specific group is selected. With reference to Figs. 32 and 33, the operation of registering chat content in the communication system 1 according to the present embodiment and the operation of displaying chat content on the group conference status screen will be described. In the following, it is assumed that the host terminal is the communication terminal 10da and the guest terminal is the communication terminal 10ac.

[0223] <Step S181> A guest at a guest terminal (communication terminal 10ac) inputs (writes) chat content to be communicated to other participants in the group conference via the input device 108 on the conference screen 1600G shown in Fig. 20 described above. Then, the display control unit 14 of the guest terminal displays the chat content input via the input device 108 on the conference screen 1600G. For example, the display control unit 14 displays the chat content in chronological order on the right edge of the conference screen 1600G, similar to the group conference status screen 1500H of the host terminal.

[0224] <Step S182> The communication unit 11 of the guest terminal transmits the guest's user ID "B_10ac" to the management system 50 together with the chat content input in step S181.

[0225] <Step S183> When the communication unit 51 of the management system 50 receives the chat content, the chat management unit 60 of the management system 50 generates a chat ID that uniquely identifies the chat content.

[0226] <Step S184> In addition, the conference management unit 59 of the management system 50 obtains the conference ID (the conference ID of the conference in which the guest is actually participating (here, a group conference)) associated with the guest's user ID "B_10ac" received by the communication unit 51 from the conference management table of the conference management DB 5004.

[0227] <Step S185> The chat management unit 60 registers a new record in the chat management table of the chat management DB 5005, associating the generated chat ID, the conference ID acquired by the conference management unit 59, the chat sender (guest user ID "B_10ac"), and the chat content received by the communication unit 51.

[0228] Through the above operations, the chat contents posted in the conference (here, the group conference) are registered in the chat management table. Next, the operation of displaying the chat contents on the group conference status screen will be described.

[0229] <Steps S186 and S187> The host selects the desired group on the group conference status screen 1500H by pressing the group a selection button 1500H-3 or the group b selection button 1500H-4 via the input device 108 of the host terminal. Here, as shown in FIG. 33, it is assumed that the host presses the group b selection button 1500H-4. Then, the communication unit 11 of the host terminal transmits the conference ID of the group conference of the selected group to the management system 50 along with a chat history acquisition request requesting acquisition of the chat history corresponding to the selected group. Note that the host terminal obtained the conference ID of the set group conference in step S80 of FIG. 17 described above.

[0230] <Step S188> When the communication unit 51 of the management system 50 receives a chat history acquisition request, the chat management unit 60 acquires, as a chat history, the chat content corresponding to the conference ID received by the communication unit 51 from the chat management table of the chat management DB 5005. In addition, the conference management unit 59 acquires, from the conference management table of the conference management DB 5004, all user IDs registered in the participation authority holder field of the record corresponding to the conference ID received by the communication unit 51.

[0231] <Step S189> The communication unit 51 transmits the chat history acquired by the chat management unit 60 and the participant information including the user ID acquired by the conference management unit 59 to the host terminal.

[0232] <Step S190> When the communication unit 11 of the host terminal receives the chat history and participant information, the display control unit 14 displays the user ID included in the received participant information in the group participation authority holder display unit 1500H-5 of the group conference status screen 1500H, and displays the received chat history in the chat display unit 1500H-6, as shown in Fig. 33. In the example shown in Fig. 33, the group participation authority holder display unit 1500H-5 displays the user ID of the participant assigned to group b, and the chat display unit 1500H-6 displays the chat content created in the group conference of group b as a chat history.

[0233] As described above, by selecting and switching between group conferences on the group conference status screen 1500H of the host terminal, it is possible to check not only the audio and participating guests in each group conference, but also the content of chats being created in real time in the selected group conference, thereby making it possible to check the progress of each group in more detail.

[0234] (Group conference termination process) Fig. 34 is a sequence diagram showing an example of a group conference ending process in the communication system according to the embodiment. Fig. 35 is a diagram showing an example of a group conference status screen when ending a group conference. Fig. 36 is a diagram showing an example of an exit request dialog box displayed when ending a group conference. The group conference ending process in the communication system 1 according to the present embodiment will be described with reference to Figs. 34 to 36. Below, a case will be described in which the communication terminal 10ac, as a guest terminal, receives a group conference ending request transmitted by the host terminal (communication terminal 10da).

[0235] <Steps S201 and S202> First, the host of the host terminal (communication terminal 10da) presses the group conference end button 1500H-9 to end the group conference via the input device 108 on the group conference status screen 1500H shown in Fig. 35. Then, the communication unit 11 of the host terminal transmits a group conference end request indicating a request to end the group conference, together with the conference IDs that identify all group conferences, to the management system 50.

[0236] <Step S203> When the communication unit 51 of the management system 50 receives a group conference end request, the conference management unit 59 acquires, from the conference management table of the conference management DB 5004, the original conference IDs associated with the conference IDs that identify all the group conferences.

[0237] <Step S204> The host terminal performs processing to change the layout of the conference screen 1300H after transmitting the group conference end request to the management system 50. Details of the layout change processing in the host terminal will be explained later with reference to FIG. 38 and the like.

[0238] <Step S205> Then, the communication unit 51 transmits the original conference ID together with a request to end the group conference to the guest terminal.

[0239] <Step S206> When the communication unit 11 of the guest terminal receives the group conference end request, the display control unit 14 displays an exit request dialog box 1600G-7 indicating that the group conference end request has been received on the conference screen 1600G displayed on the display 120 of the guest terminal, as shown in Fig. 36. The exit request dialog box 1600G-7 shown in Fig. 36 indicates that the group conference end request has been received, and is a user interface for specifying whether or not to permit exit from the group conference. The guest can confirm that the group conference end request has been received by viewing the exit request dialog box 1600G-7.

[0240] The exit request dialog box 1600G-7 includes an exit button 1600G-8 for permitting the user to leave the group conference. Note that the exit request dialog box 1600G-7 may also include a button for temporarily refusing to leave the group conference in order to carry out remaining work within the group conference (for example, leaving a chat about the conclusions of the group conference). In this case, after completing the remaining work, the user can exit the group conference again by clicking the exit button 1600G-5.

[0241] <Step S207> When the leave button 1600G-8 is pressed by operating the input device 108 of the guest terminal, the operation input receiving unit 12 receives a response indicating that the guest is leaving the group conference.

[0242] <Step S208> Next, the communication unit 11 of the guest terminal transmits to the management system 50 the user ID "B_10ac" of the guest of the guest terminal together with an exit response indicating that the guest has left the group conference.

[0243] <Step S209> When the communication unit 51 receives the leave response, the conference management unit 59 of the management system 50 deletes the user ID "B_10ac" of the guest from the participant field of the record of the group conference to which the guest of the guest terminal that sent the leave response belongs, in the conference management table of the conference management DB 5004. Furthermore, the conference management unit 59 adds the user ID "B_10ac" of the guest to the participant field of the record of the original conference (general conference) indicated by the original conference ID of the record indicating the group conference. As a result, the participant (guest) of the guest terminal is treated as having left the group conference and moved to the original general conference.

[0244] <Step S210> The communication unit 51 of the management system 50 transmits the participant information (such as the guest user ID) of the guest terminal that transmitted the exit response to the host terminal.

[0245] <Step S211> When the communication unit 11 of the host terminal receives the participant information, the display control unit 14 updates the group a status display unit 1500H-1 of the group conference status screen 1500H by deleting the video of the guest identified by the user ID "B_10ac" included in the participant information received by the communication unit 11. The display control unit 14 also causes the chat display unit 1500H-6 to display a chat message indicating that the guest has left the group conference.

[0246] Then, the display control unit 14 adds and updates the video of the guest identified by the user ID included in the participant information on the conference screen 1300H that shows the state of the general conference.

[0247] <Step S212> The guest terminal transmits the user ID of the guest of the guest terminal together with an exit response indicating that the guest has left the group conference to the management system 50, and then performs processing to change the layout of the conference screen 1600G. Details of the layout change processing in the guest terminal will be described later with reference to FIG.

[0248] <Step S213> The display control unit 14 of the guest terminal transitions the conference screen 1600G, which has been subjected to the layout change processing and is being displayed on the display 120, to the screen of the original conference (general conference).

[0249] <Step S214> The details of the process of leaving the guest terminals participating in each group conference in steps S206 to S211 will be described later with reference to FIG.

[0250] <Guest device exit process at the end of a group conference> 37 is a sequence diagram showing an example of a process for deleting a group conference status screen in the communication system according to the embodiment. The process for leaving the group conference by guest terminals participating in each group conference in step S214 in FIG. 34 will be described with reference to FIG.

[0251] <<Step S2141>> When the communication unit 11 of each communication terminal 10 that is a guest terminal receives a group conference end request from the management system 50, the display control unit 14 of that communication terminal 10 displays an exit request dialog box 1600G-7 indicating that the group conference end request has been received, on the conference screen 1600G displayed on the display 120 of the guest terminal, as shown in FIG. 36 above. The guest can confirm that the group conference end request has been received by viewing the exit request dialog box 1600G-7. The processing of step S2141 is the same as step S206 of FIG. 34 above.

[0252] <<Step S2142>> When the leave button 1600G-8 is pressed by operating the input device 108 of the guest terminal, the operation input receiving unit 12 receives a response to the effect of leaving the group conference. The processing in step S2142 is the same as step S207 in FIG. 34 described above.

[0253] <<Step S2143>> Next, the communication unit 11 of the guest terminal transmits the user ID of the guest of the guest terminal together with an exit response indicating exit from the group conference to the management system 50. The process of step S2143 is the same as step S208 in FIG. 34 described above.

[0254] <<Step S2144>> When the communication unit 51 receives the leave response, the conference management unit 59 of the management system 50 deletes the user ID of the guest from the participant field of the record of the group conference to which the guest of the guest terminal that sent the leave response belongs, in the conference management table of the conference management DB 5004. Furthermore, the conference management unit 59 adds the user ID of the guest to the participant field of the record of the original conference (general conference) indicated by the original conference ID of the record indicating the group conference. As a result, the participant (guest) of the guest terminal is treated as having left the group conference and moved to the original general conference. The processing of step S2144 is the same as step S209 in FIG. 34 described above.

[0255] <<Step S2145>> In addition, the conference management unit 59 uses the conference IDs of all group conferences received in step S202 to obtain, from the conference management table of the conference management DB 5004, all user IDs of guests currently participating in each group conference.

[0256] <<Step S2146>> The conference manager 59 then determines whether all guests have left each group conference. If all guests have not yet left each group conference (step S2146: No), the process returns to step S2143 and waits until a leave response is received from the guest terminal of the guests who have not left. On the other hand, if all guests have left each group conference (step S2146: Yes), the process proceeds to step S2147.

[0257] <<Step S2147>> When the conference management unit 59 of the management system 50 confirms that all guests have left each group conference, the communication unit 51 transmits a group conference end notification indicating that the group conference has ended to the host terminal.

[0258] <<Step S2148>> When the communication unit 11 of the host terminal receives a group conference end notification, the display control unit 14 deletes (hides) the group conference status screen 1500H because there are no guest videos remaining in the group a status display area 1500H-1 and the group b status display area 1500H-2 of the group conference status screen 1500H. In addition, in this state, the conference screen 1300H of the guest terminal displays videos of all the guests who participated in each group conference.

[0259] <Layout change process for the host terminal's conference screen> Fig. 38 is a sequence diagram showing an example of layout change processing of a conference screen of a general conference on the host terminal side in a communication system according to an embodiment. Fig. 39 is a diagram showing an example of a conference screen of a general conference whose layout has been changed after a group conference has ended. Fig. 40 is a diagram showing another example of a conference screen of a general conference whose layout has been changed after a group conference has ended. Fig. 41 is a diagram showing another example of a conference screen of a general conference whose layout has been changed after a group conference has ended. Details of the layout change processing on the host terminal in step S204 in Fig. 34 will be described with reference to Figs. 38 to 41.

[0260] <<Step S2041>> The communication unit 11 of the host terminal (communication terminal 10da) transmits to the management system 50 the conference IDs of all group conferences together with a participation authority information acquisition request for requesting acquisition of participation authority holders in each group conference.

[0261] <<Step S2042>> When the communication unit 51 of the management system 50 receives a request to obtain participation authority information, the conference management unit 59 obtains all user IDs included in the participation authority holder field of each group conference from the conference management table of the conference management DB 5004 using the conference IDs of all group conferences received in step S2041.

[0262] <<Step S2043>> The communication unit 51 transmits the participation authority holders (guest user IDs) of each group conference acquired in step S2042 to the host terminal in association with the conference IDs of the respective group conferences.

[0263] <<Step S2044>> When the communication unit 11 (acquisition unit) of the host terminal receives participation authority holders (an example of participant information) of each group conference, the display control unit 14 changes the layout of a conference screen 1300H showing the general conference, for example, as shown in Fig. 39, to clearly indicate which group conference the participant attended. Specifically, the display control unit 14 divides the display area so that videos of the participants (guests) who attended each group conference (an example of participant information) are separately displayed, as in the conference screen 1300H shown in Fig. 39. That is, the display control unit 14 divides the display area into a group participant display unit 1300H-5 that displays group participant video 1300H-5a, which is video of the participants who attended the group conference of group a, and a group participant display unit 1300H-6 that displays group participant video 1300H-6a, which is video of the participants who attended the group conference of group b. Then, each time a participant leaves the group conference through the processing of steps S206 to S210 in Fig. 34, the display control unit 14 displays an image of that participant in the area (group participant display area 1300H-5 or group participant display area 1300H-6) on the conference screen 1300H that displays the group conference in which that participant participated. The conference screen 1300H shown in Fig. 39 shows a state in which all participants who had been participating in the group conference have left the group conference and moved to the general conference.

[0264] As described above, after the group conference ends, the conference screen 1300H showing the general conference displays participant videos in separate display areas so that it is possible to see which group conference the participant was in. This makes it easy to know which group the participant belonged to when the participant leaves the group conference on the host terminal.

[0265] Note that the display mode for indicating which group conference a participant participated in on the conference screen 1300H is not limited to the mode in which the participant display area is divided by group as shown in FIG. 39 , and may be, for example, a display mode as shown in FIG. 40 . That is, on the conference screen 1300H shown in FIG. 40 , the group conference in which the participant participated may be indicated by a colored frame around the participant video 1300H-1 (an example of information indicating a participant) of the participant. Specifically, the display control unit 14 frames the participant video 1300H-1 of the participant who participated in the group conference of group a with an image frame 1300H-1a in a color that identifies group a, and frames the participant video 1300H-1 of the participant who participated in the group conference of group b with an image frame 1300H-1b in a color that identifies group b. This also makes it easy to determine which group a participant belonged to when the participant leaves the group conference on the host terminal. The frame of the participant video 1300H-1 is not limited to being distinguished by color, but may be distinguished by, for example, a pattern or the like.

[0266] Further, as another display mode that allows a participant to know which group conference a participant participated in on the conference screen 1300H, for example, a display mode as shown in Fig. 41 may be used. That is, on the conference screen 1300H shown in Fig. 41, which group conference a participant participated in may be displayed near (for example, below) the participant video 1300H-1 of the participant (an example of information indicating a participant) a participant information display section 1300h-7 (an example of information indicating a group conference) including the group name of the group conference in which the participant participated. Specifically, the display control unit 14 displays a participant information display section 1300h-7 including the group name "a" near the participant video 1300H-1 of the participant who participated in the group conference of group a, and displays a participant information display section 1300h-7 including the group name "b" near the participant video 1300H-1 of the participant who participated in the group conference of group b. This also makes it possible to easily know, at the host terminal, which group the participant belonged to when the participant leaves the group conference.

[0267] <Processing to change the layout of the conference screen on the guest device> 42 is a sequence diagram showing an example of a layout change process of a conference screen of a general conference on the guest terminal side in the communication system according to the embodiment. Details of the layout change process on the guest terminal in step S212 in FIG. 34 will be described with reference to FIG.

[0268] <<Step S2121>> The communication unit 11 of the communication terminal 10, which is a guest terminal, transmits the conference IDs of all group conferences together with a participation authority information acquisition request for acquiring the participation authority holders for each group conference to the management system 50. Note that the guest terminal has acquired the conference IDs of all group conferences in step S82 of FIG. 17 described above.

[0269] <<Step S2122>> When the communication unit 51 of the management system 50 receives a request to obtain participation authority information, the conference management unit 59 obtains all user IDs included in the participation authority holder field of each group conference from the conference management table of the conference management DB 5004 using the conference IDs of all group conferences received in step S2121.

[0270] <<Step S2123>> The communication unit 51 transmits the participation authority holders (user IDs) of each group conference acquired in step S2122 to the guest terminal in association with the conference IDs of the respective group conferences.

[0271] <<Step S2124>> When the communication unit 11 (acquisition unit) of the guest terminal receives the participation authority holders (an example of participant information) of each group conference, the display control unit 14 changes the layout of the conference screen 1600G in a manner similar to the layout change of the conference screen 1300H shown in Figures 39 to 41 described above, to clearly indicate which group conference the participant has participated in. Then, each time a participant leaves the group conference through the processing of steps S206 to S210 in Figure 34, the display control unit 14 displays an image of the participant on the conference screen 1600G so that the group conference in which the participant participated can be distinguished.

[0272] When the layout of the conference screen 1600G is changed as shown in Fig. 39, the arrangement of the guest's own video 1600G-4, which is the guest's own video, may be changed so that it belongs to the display area of ​​the group conference in which the guest participated. When the layout of the conference screen 1600G is changed as shown in Fig. 40, the frame around the guest's own video 1600G-4, which is the guest's own video, may also be displayed in a color that identifies the group conference in which the guest participated. When the layout of the conference screen 1600G is changed as shown in Fig. 41, information including the group name of the group conference in which the guest participated may be displayed near the guest's own video 1600G-4, which is the guest's own video.

[0273] As described above, after the group conference ends, on the conference screen 1600G showing the general conference, participant images are displayed in separate display areas so that it is possible to see which group conference the participant was in. This makes it easy to know on the guest terminal which group the participant belonged to when the participant leaves the group conference.

[0274] As described above, in the communication system 1 according to the present embodiment, when a participant who has been participating in a group conference leaves the group conference, the conference screen (conference screen 1300H, conference screen 1600G) showing the general conference on the communication terminal 10 displays the group conference in which the participant participated so that the participant can see which group conference the participant participated in. For example, the display area of ​​the participants may be divided by group as shown in FIG. 39, or the participant's video may be surrounded by a color-coded frame corresponding to each group as shown in FIG. 40, or information including the group name of the group conference the participant participated in may be displayed near the participant's video as shown in FIG. 41. This makes it easy to know which group the participant belonged to when the participant leaves the group conference. In particular, since it is possible to clearly indicate which group conference each participant participated in even after the group conference has ended, it is easy to know which group each participant belonged to.

[0275] Furthermore, on the host terminal that starts a group conference, the voice, chat content, and participating guests for each group conference can be checked on the group conference status screen 1500H. This allows the host to check the progress of each group conference without having to attend each group conference. However, the host can also participate in a group conference of his or her choice, in which case the progress of the group conference can be checked by directly communicating with the participants (guests) participating in the group conference.

[0276] 38 and 42, after the group conference ends, the conference screen (conference screen 1300H, conference screen 1600G) showing the general conference on the communication terminal 10 displays the group conference in which the participant participated so that the participant can see which group conference they participated in. However, this is not limited to this. That is, even during the group conference, the communication terminal 10 (host terminal, guest terminal) may change the layout of the conference screen so that the participant can see which group conference they participated in, and when a participant leaves a group conference and rejoins the general conference while displaying the general conference status, the participant can see which group conference they belonged to. For example, when a guest terminal leaves a group conference and returns to the general conference, the guest terminal may obtain the participation authority holders of each group, and the participant can see which group conference the displayed participant belonged to while displaying the general conference status. Also, for example, in the case of the host terminal, at the timing of the processing of step S88 in FIG. 17 described above, the participants in the general conference have already been assigned to group conferences at this point, so the layout of the conference screen 1300H displayed on the guest terminal may be changed to one of the modes shown in FIGS. 39 to 41.

[0277] (Another form of software configuration of communication terminal) 43 is a diagram showing an example of a software configuration when using a Web application of the communication terminal according to the embodiment. Another form of the software configuration of the communication terminal 10 will be described with reference to FIG.

[0278] While the operation of communication application A executed on communication terminal 10 has been described in FIG. 4 above, similar processing can also be achieved by a Web application. A Web application operates on a browser, for example, by cooperation between a JavaScript (registered trademark) program and a program on a Web server, and is used by a user on the browser. That is, as shown in FIG. 43, communication terminal 10 downloads program WA (HTML (HyperText Markup Language) + JavaScript + CSS (Coefficient Of Performance), etc.) from management system 50 and executes it on browser 1040. Browser 1040 operates under the control of OS 1020.

[0279] The communication terminal 10 can use the services provided by the management system 50 by transmitting and receiving data to and from the management system 50 using protocols such as HTTP (Hypertext Transfer Protocol) or HTTPS (Hypertext Transfer Protocol Secure). In this type of usage, there is no need to download the communication application A to the communication terminal 10 in advance.

[0280] Each function of the above-described embodiments can be realized by one or more processing circuits. Here, the term "processing circuit" includes a processor programmed to execute each function by software, such as a processor implemented by an electronic circuit, and devices designed to execute each of the above-described functions, such as an ASIC, a DSP (Digital Signal Processor), an FPGA, a SOC (System on a Chip), a GPU (Graphics Processing Unit), or a conventional circuit module.

[0281] Furthermore, in the above-described embodiments, when at least one of the functional units of the communication terminal 10 and the management system 50 is realized by executing a program, the program is provided by being pre-installed in a ROM or the like. Furthermore, the program executed by the communication terminal 10 and the management system 50 according to the above-described embodiments may be provided by being recorded in an installable or executable file format on a computer-readable recording medium such as a CD-ROM (Compact Disc Read Only Memory), a flexible disk (FD), a CD-R (Compact Disk-Recordable), a DVD, or an SD card. Furthermore, the program executed by the communication terminal 10 and the management system 50 according to the above-described embodiments may be provided by being stored on a computer connected to a network such as the Internet and downloaded via the network. Furthermore, the program executed by the communication terminal 10 and the management system 50 according to the above-described embodiments may be provided or distributed via a network such as the Internet. Furthermore, the program executed by the communication terminal 10 and the management system 50 according to the above-described embodiments has a modular configuration including at least one of the above-described functional units. In actual hardware, the CPU reads and executes the program from the above-described storage device, thereby loading and generating the above-described functional units into a main storage device. [Explanation of symbols]

[0282] 1. Communication Systems 2. Communication Network 2a~2d LAN 2ab, 2cd dedicated lines 2i Internet 10, 10aa, 10ab, 10ac, 10ba, 10bb, 10ca, 10cb, 10da, 10db communication terminal 11 Communications Department 12 Operation input reception section 13 Imaging unit 14 Display control unit 15 Audio input section 16 Audio output section 17 Memory / readout section 18 Memory section 19 Authentication Request Section 50 Management Systems 51 Communications Department 52 Authentication Section 53 State Management Unit 54 Extraction part 55 Terminal status acquisition unit 56 Session control section 57 Memory / readout section 58 Memory section 59 Conference Management Department 60 Chat Management Department 70, 70a~70d, 70ab, 70cd Router 90 Program Delivery System 101 CPU 102 ROM 103 RAM 104 Flash Memory 105 Auxiliary storage device 106 Media 107 Media Drive 108 Input Device 110 Bus Line 111 Network I / F 112 Camera 112c cable 113 Image sensor I / F 114 Mike 114c cable 115 Speaker 115c cable 116 Audio input / output I / F 119 Display I / F 120, 120aa, 120bb, 120ca, 120db display 120c cable 201 CPU 202 ROM 203 RAM 205 Auxiliary storage device 206 Recording Media 207 Media Drive 208 Display 209 Network Interface 210 Bus Line 211 keyboard 212 Mouse 213 DVD 214 DVD drive 1010 Work area 1020 OS 1040 Browser 5001 Authentication Management DB 5002 Terminal management database 5003 Session Management DB 5004 Conference Management DB 5005 Chat Management DB A communication app WA Program [Prior art documents] [Patent documents]

[0283] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-215553

Claims

1. A communication terminal capable of making a call with another communication terminal by transmitting and receiving a voice signal via a network, an acquisition unit that acquires information on participants for each group conference from a conference storage unit in which information on two or more group conferences derived from a general conference is registered; a display control unit that changes the layout of a conference screen of the general conference to be displayed on a display unit based on the information of the participants for each of the group conferences acquired by the acquisition unit so as to clearly indicate which of the group conferences the participants attended; and A communication terminal equipped with

2. The communication terminal according to claim 1 , wherein the general conference is an original conference from which the two or more group conferences are derived.

3. 3. The communication terminal according to claim 1, wherein the acquisition unit acquires the information of the participants for each group conference from the conference storage unit at least after an operation to end each group conference has started.

4. 3. The communication terminal according to claim 1, wherein the acquisition unit acquires the information on the participants for each group conference from the conference storage unit while each group conference is being held.

5. The communication terminal according to any one of claims 1 to 4, wherein the display control unit changes the layout on the conference screen so as to divide a display area for each group conference and display information indicating the participant in the display area corresponding to the group conference in which the participant participated.

6. The communication terminal according to any one of claims 1 to 4, wherein the display control unit changes the layout on the conference screen by outlining information indicating the participants with a frame that is color-coded according to the group conference in which the participant participated.

7. The communication terminal according to any one of claims 1 to 4, wherein the display control unit changes the layout so that information indicating the group conference in which the participant participated is displayed near information indicating the participant displayed on the conference screen.

8. The communication terminal according to any one of claims 1 to 7, wherein the display control unit causes the display unit to display a status screen that displays information indicating which participants are participating in each of the group conferences.

9. A communication system having two or more communication terminals and a management system that relays voice signals of the communication terminals, The management system includes: a conference management unit that manages a conference memory unit in which information on at least two or more group conferences derived from a general conference is registered; The communication terminal an acquisition unit that acquires participant information for each group conference from the conference storage unit via the conference management unit; a display control unit that changes the layout of a conference screen of the general conference to be displayed on a display unit based on the information of the participants for each of the group conferences acquired by the acquisition unit so as to clearly indicate which of the group conferences the participants attended; and A communication system comprising:

10. A communication method for a communication terminal capable of making a call with another communication terminal by transmitting and receiving a voice signal via a network, comprising: an acquisition step of acquiring information on participants for each group conference from a conference storage unit in which information on two or more group conferences derived from a general conference is registered; a display control step of changing the layout of the conference screen of the general conference to be displayed on a display unit based on the acquired participant information for each of the group conferences so as to clearly indicate which of the group conferences the participant participated in; A communication method comprising:

11. On the computer, an acquisition step of acquiring information on participants for each group conference from a conference storage unit in which information on two or more group conferences derived from a general conference in which other communication terminals and communication terminals capable of communicating with the other communication terminals by transmitting and receiving voice signals via a network participate; a display control step of changing the layout of the conference screen of the general conference to be displayed on a display unit based on the acquired participant information for each of the group conferences so as to clearly indicate which of the group conferences the participant participated in; A program to execute.

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