JPH07212733A - Terminal equipment for video conference between multi-points - Google Patents

Abstract

PURPOSE:To obtain an inter-multi-point video conference terminal equipment in which simultaneous transmission of data by plural terminal equipments is avoided without revamping an existing inter-multi-point communication equipment. CONSTITUTION:Simultaneous transmission by plural terminal equipments 12, 13, 14 is avoided by providing a token control function in which only a terminal equipment reserving a token processes transmission data into packet data and sends the packet data to the terminal equipments. The token control function sends a token request packet from a control section 20 of the terminal equipment side to other terminal equipment via an inter-multi-point communication equipment 10, and receives a token transfer packet from other terminal equipment having a token by a selective multiple address distribution function and sets the presence of the packet to a token presence storage section 27 to realize through the acquisition of the token. The selective multiple address distribution function uses a sender user header generating section 24 to add a transmission destination identifier to a packet and the destination uses a user header analysis section 23 to identify it to receive the packet normally thereby realizing the existing multiple address distribution function of the inter-multi-point communication equipment 10 without revamping the existing multiple address distribution function.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention utilizes a data broadcasting function of a multipoint communication device for providing a videoconference service between multiple points by connecting a plurality of videoconference terminals in a star pattern. Then, the present invention relates to a transmission right control technique for avoiding simultaneous data transmission by a plurality of terminals.

[0002]

2. Description of the Related Art Multipoint communication devices for providing a videoconference service between multiple points have already been internationally standardized and are commercially available from various companies. FIG. 8 shows a connection configuration example of a conventional multipoint video conference system. Since the main use of the multipoint communication device 1 is a video conference, in general, a plurality of terminals 3 to 3 are connected via a communication network 2 such as ISDN.
6 has a star-type call connection function, a function of adding voices sent from the respective terminals 3 to 6 and distributing them to other terminals, and switching and selecting images sent from the respective terminals 3 to 6, It has an essential function of delivering the video from any one of the terminals 3 to 6.

[0003]

However, in the above-mentioned conventional multipoint communication device, since data media such as FAX data, character data, and drawing are not considered to be essential, it is considered as a multipoint communication device. Has only the function of broadcasting the data sent from one terminal to all the other terminals as it is without processing it. Therefore, the existing multipoint communication device has a problem that data cannot be sent to only some of the plurality of partner terminals.

If the one-way transfer control of data cannot be performed in this way, the following problem of simultaneous transmission arises.
The biggest advantage of handling data at a video conference terminal is that the materials used in the conference can be digitized and the materials can be transmitted to each terminal via the same line as the video and audio so that the conference can be performed while viewing the same materials. Is. In this case, it takes time to send the material immediately before using it, and it will interfere with the conference.In general, therefore, the material to be used is sent to other terminals in advance and saved in the storage device of each terminal. A method is conceivable in which, when used by a user, the material name is transmitted to each terminal in the form of a command, each terminal independently retrieves the instructed material from its own storage device and displays it on the monitor. At this time, if the users of a plurality of terminals simultaneously send commands indicating different material names, there is a problem in that the displayed material will be different for each terminal depending on which command is received first by each terminal.

The present invention has been made to solve the above problems, and an object thereof is to avoid simultaneous transmission of data by a plurality of terminals without modifying an existing multipoint communication device. The purpose is to provide a terminal for multi-point video conference.

[0006]

In order to achieve the above-mentioned object, the present invention accommodates a plurality of video conference terminals via a communication line, and after receiving data transmitted from the video conference terminals, In a multipoint videoconference terminal connected to a multipoint communication device having a function of broadcasting to other videoconference terminals, a destination identifier and a source identifier are added to a packet to be transmitted and a destination and a source are added. Means to specify
When transmission data is generated, if the transmission right is held, the transmission data is packetized and transmitted, and if the transmission right is not held, the transmission of the transmission data is suspended until the transmission right is acquired. In addition, a means for creating and transmitting a transmission right request packet, and if the destination identifier of the received packet includes the destination of the own terminal, the packet is normally received and the destination of the own terminal is included. If it does not exist, a method of discarding the packet and when the transmission right request packet is normally received, if the transmission right is not held or if the transmission right is held and there is transmission data to be transmitted If the transmission right request packet is discarded and the transmission right is held and there is no transmission data to be transmitted, the transmission source specified by the transmission source identifier of the transmission right request packet A method of sending a transmission right transfer packet to a terminal as a destination and abandoning the transmission right. When the transmission right transfer packet is normally received, the transmission right transfer packet is discarded and the transmission right transfer packet is discarded. Means for starting transmission when there is transmission data for which the transmission right is held and acquired and the transmission is held when the transmission right is not held.

[0007]

In the multipoint video conference terminal of the present invention, only the terminal having the transmission right has the transmission right control function capable of packetizing and transmitting the transmission data.
Avoid simultaneous transmission by multiple terminals. Such a transmission right control function transmits a transmission right request packet to another terminal from the terminal side that wants to acquire the transmission right, and returns it from the other terminal that has the transmission right by the selective broadcast distribution function. This is realized by receiving the transmission right transfer packet and acquiring the transmission right. Here, the selective broadcast distribution function of transmitting data only to some terminals adds an identifier for designating the destination and the source at the source terminal, and only the destination can identify this. By receiving the packet normally, the existing broadcast distribution function of the multipoint communication device can be realized without modification.

[0008]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 is a diagram showing a configuration of an embodiment of the present invention, showing a configuration example of a video conference terminal and a connection example of the video conference terminal and a multipoint communication device. In the figure, 10 is a multipoint communication having a function of accommodating a plurality of video conference terminals via a communication line, receiving data transmitted from the video conference terminals, and then distributing the broadcast data to other video conference terminals. It is a device. Further, 12, 13, 14 are the above-mentioned video conference terminals, and 15, 16, 17 are the above-mentioned lines. In this example, an example of connection with the multipoint communication device when there are three video conference terminals is shown. Each of the video conference terminals 12, 13, 14 is connected to the multipoint communication device 10 in a star form via lines 15, 16, 17 via the communication network 11.

Each of the video conference terminals 12, 13 and 14 has a control unit 20 and a user header creating unit 24 as means for adding a destination identifier and a source identifier to the packet to be transmitted, while the data of the received packet is received. If the identifier of the own terminal is included in the destination identifiers added to the packet, the packet is normally received, and if the identifier of the own terminal is not included, the packet is discarded as means for discarding the packet.
And a user header analysis unit 23. Furthermore, when transmission data is generated, if the transmission right is held, the transmission data is packetized and transmitted, and if the transmission right is not held, the transmission data is transmitted until the transmission right is acquired. When the transmission right request packet is received and the transmission right is not held when the transmission right request packet is received, or when the transmission right request packet is received In case of possessing the right and if there is transmission data to be transmitted, the transmission right request packet is discarded, and in case of possessing the transmission right and there is no transmission data to be transmitted. A means for transmitting a transmission right transfer packet with the terminal of the transmission source specified by the transmission source identifier of the transmission right request packet as the destination and abandoning the transmission right, and a transmission right transfer packet When received, the transmission right transfer packet is discarded if the transmission right is held, and if the transmission right is not held, the transmission right is held and acquired, and the above transmission is suspended. In this case, the control unit 20 and the transmission right presence / absence storage unit 27 are provided as means for starting the transmission.
In addition, each of the video conference terminals 12, 13, and 14 has a higher-order application unit 21, a line interface unit 22 connected to the lines 15, 16, and 17, and a transmission / reception data buffer unit 25. Each of the above parts 20, 21, 2
2, 23, 24, 25 and 27 are connected by a data bus 26.

The operation and action of the embodiment having the above configuration will be described below.

First, a case where a transmission right request packet is transmitted at the representative example of the video conference terminal 12 will be described. FIG. 2 is a flow chart for explaining the operation.
The control unit 20 temporarily transfers the data received from the higher-level application unit 21 by designating the transmission destination to the reception / transmission data buffer unit 25 via the data bus 26. Control unit 2
0 indicates a transmission right presence / absence storage unit 27 via the data bus 26.
Check if you have the right to send. If the terminal has the transmission right, the control unit 20 determines the user header creation unit 24 based on the destination specified by the upper application unit 21.
Instruct to create a destination identifier and a source identifier as a user header. Next, the control unit 20 packetizes the data stored in the transmission / reception data buffer unit 25 into a predetermined data length, and adds the user header read from the user header creation unit 24 to the packetized data. , To the line interface unit 22 via the data bus 26. The line interface unit 22
The data packet is transmitted to the multipoint communication device 10 via the line 17. The multipoint communication device 10 broadcast-receives the received data as it is to the video conference terminals 14 and 13 via the lines 15 and 16. Video conference terminal 1
Looking at the transmission destination identifier of the received data packet, 4 and 13 normally receive the data if the own terminal is designated, and discard the data if the own terminal is not designated. On the other hand, if the device does not have the transmission right, the control unit 2
0 creates a transmission right request packet, and instructs the user header creation unit 24 to create a destination identifier and a source identifier. In this case, all other terminals are designated as the destination identifiers. The control unit 20 adds the user header read from the user header creation unit 24 to the transmission right request packet, and the line interface unit 22 via the data bus 26.
Transfer to. The line interface unit 22 transmits to the multipoint communication device 10 via the line 17. The multipoint communication device 10 uses the received data as it is for the lines 15, 1
Broadcast distribution to the video conference terminals 14 and 13 via 6. The control unit 20 suspends the transmission of the data stored in the transmission / reception data buffer unit 25 until the transmission right transfer packet is received.

FIG. 3 shows an example of the format of a packet transferred on the lines 15, 16 and 17. The packet in this embodiment is configured by adding a user header including a transmission destination identifier and a transmission source identifier to packetized user data or a command such as a transmission right request or a transmission right transfer. The user header is used in the terminal, and the multipoint communication device 10 does not process the user header. Further, the transmission destination identifier and the transmission source identifier may be a telephone number of each terminal, or the bit position of the user header may be assigned to each terminal. For example, if the terminal first connected to the multipoint communication device 10,
Immediately after all the other terminals are connected to the multipoint communication device 10, the correspondence table of the telephone number of each terminal and the identifier is transmitted, and the subsequent data transmission / reception can identify the terminal by this bit position. User header can be shortened and overhead is reduced. FIG. 4 shows an example of the correspondence table of the telephone numbers of the terminals and the terminal numbers, and FIG. 5 shows an example of the user header by the terminal numbers. In this example, a case where a video conference is held between 12 terminals is shown, and the user when the terminal with the terminal number 1 transmits data to the terminals with the terminal numbers 4, 6, 8, and 9. Shows the header.

Next, a case where the representative example video conference terminal 12 receives a transmission right request packet will be described. FIG. 6 is a flowchart explaining the operation.
When the line interface unit 22 receives the transmission right request packet from the multipoint communication device 10 via the line 17, it notifies the control unit 20. The control unit 20 transfers the user header and the data to the user header analysis unit 23 and the transmission / reception data buffer unit 25 via the data bus 26, respectively.
The user header analysis unit 23 interprets the destination identifier of the user header and, if the identifier of the own terminal is not included, notifies the control unit 20 to that effect. The control unit 20 instructs the transmission / reception data buffer unit 25 to discard the received data. On the other hand, if the destination identifier of the user header includes the identifier of the terminal itself, the user header analysis unit 23 notifies the control unit 20 to that effect. The control unit 20 reads the received data from the transmission / reception data buffer unit 25 via the data bus 26, and when the received data is a transmission right request packet, the transmission right presence / absence storage unit 27 sends the transmission right to the transmission right request packet via the data bus 26. Check for the presence. If the terminal does not have the transmission right, the control unit 20 instructs the transmission / reception data buffer unit 25 to discard the received data. If the terminal has the transmission right, the control unit 20 checks whether or not there is data pending transmission in the transmission / reception data buffer unit 25, and if there is, the received transmission right request packet is sent to the transmission / reception data buffer unit 25. Direct the disposal of. If there is no data pending transmission, the control unit 20 creates a transmission right transfer packet and instructs the user header creation unit 24 to create a destination identifier and a source identifier. In this case, the transmission destination identifier indicates the transmission source terminal of the transmission right request packet. The control unit 20 adds the user header read from the user header creation unit 24 to the transmission right transfer packet, transfers it to the line interface unit 22 via the data bus 26, and stores the transmission right presence / absence via the data bus 26. No transmission right is set in the section 27 and the transmission right is abandoned. The line interface unit 22 transmits to the multipoint communication device 10 via the line 17. The multipoint communication device 10 uses the received data as it is for the line 1.
Broadcast distribution is carried out to the video conference terminals 14 and 13 via 5 and 16.

Next, a case where the transmission right transfer packet is received by the representative video conference terminal 12 will be described. FIG. 7 is a flowchart explaining the operation.
When the line interface unit 22 receives the transmission right transfer packet from the multipoint communication device 10 via the line 17, it notifies the control unit 20. The control unit 20 transfers the user header and the data to the user header analysis unit 23 and the transmission / reception data buffer unit 25 via the data bus 26, respectively.
The user header analysis unit 23 interprets the destination identifier of the user header and, if the identifier of the own terminal is not included, notifies the control unit 20 to that effect. The control unit 20 instructs the transmission / reception data buffer unit 25 to discard the received data. On the other hand, if the destination identifier of the user header includes the identifier of the terminal itself, the user header analysis unit 23 notifies the control unit 20 to that effect. The control unit 20 reads the received data from the transmission / reception data buffer unit 25 via the data bus 26, and if it is a transmission right transfer packet, the transmission right presence / absence storage unit 27 sends the transmission right to the transmission right transfer packet via the data bus 26. Check for the presence. If the terminal has the transmission right, the control unit 20 instructs the transmission / reception data buffer unit 25 to discard the received transmission right transfer packet. If the terminal does not have the transmission right, the control unit 20 sets the transmission right presence / absence storage unit 27 to have the transmission right via the data bus 26 and acquires the transmission right. Further, the control unit 20 controls the transmission / reception data buffer unit 2
If there is data pending transmission in 5, the data is packetized, a user header is added, and the data packet is transmitted, as described above.

The above embodiment has been described on the premise that any terminal has the transmission right. However, if the transmission right does not exist in any of the terminals at the time of starting communication, for example, the conference participant's The terminal with the lowest telephone number (Fig. 5
In this example, the first transmission right may be given to the terminal with the terminal number 12). Specifically, when the telephone numbers of the conference participants are first transmitted to each other, the telephone numbers of the own terminal and other terminals are compared with each other, and the first transmission right is set when the telephone number of the own terminal is the smallest. Also, when a transmission right request packet is sent and the transmission right request packet is discarded by the terminal having the transmission right and cannot acquire the transmission right, the request source (sending source) terminal has a timer and automatically operates. Specifically, the transmission right request packet may be retransmitted, or the terminal may retransmit the transmission right request packet based on a user instruction.

[0017]

As described above, according to the multipoint video conference terminal of the present invention, the video transmission terminal has a data transmission right control function capable of transmitting data only by the terminal having the transmission right. Since it is provided, simultaneous transmission of data by a plurality of terminals can be avoided without modifying the existing multipoint communication device.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a video conference terminal showing an embodiment of the present invention.

FIG. 2 is a flowchart illustrating an operation when transmission data is generated in the above embodiment.

FIG. 3 is a diagram showing an example of a packet format in the above embodiment.

FIG. 4 is a diagram showing an example of a correspondence table of telephone numbers and terminal numbers in the above embodiment.

FIG. 5 is a diagram showing a configuration example of a user header according to a terminal number in the above embodiment.

FIG. 6 is a flowchart illustrating an operation when a transmission right request packet is received in the above embodiment.

FIG. 7 is a flowchart illustrating an operation when a transmission right transfer packet is received in the above embodiment.

FIG. 8 is a diagram showing a connection configuration example of a conventional system.

[Explanation of symbols]

 10 ... Multipoint communication device 11 ... Communication network 12, 13, 14 ... Video conference terminal 15, 16, 17 ... Line 20 ... Control part 21 ... Upper application part 22 ... Line interface part 23 ... User header analysis part 24 ... User Header creation unit 25 ... Transmission / reception data buffer unit 26 ... Data bus 27 ... Transmission right presence / absence storage unit

Claims (1)

[Claims] 1. A multipoint communication having a function of accommodating a plurality of video conference terminals via a communication line, receiving data transmitted from the video conference terminals, and then broadcasting the data to other video conference terminals. In a multipoint video conference terminal connected to a device, a means for designating a destination and a source by adding a destination identifier and a source identifier to a packet to be transmitted, and a transmission right when transmission data occurs If the transmission data is held, the transmission data is packetized and transmitted, and if the transmission right is not held, the transmission of the transmission data is suspended and a transmission right request packet is created until the transmission right is acquired. The means for transmitting and the destination identifier of the received packet, if the destination of the own terminal is included, normally receive the packet, and if the destination of the own terminal is not included, discard the packet. And when the transmission right request packet is received normally, if the transmission right is not held, or if the transmission right is held and there is transmission data to be transmitted, the transmission right request packet is sent. When the packet is discarded and the transmission right is held and there is no transmission data to be transmitted, the transmission right transfer packet is transmitted with the transmission source terminal specified by the transmission source identifier of the transmission right request packet as the transmission destination. A method of transmitting and abandoning the transmission right, and when the transmission right transfer packet is normally received, discards the transmission right transfer packet if the transmission right is held, and sends it if the transmission right is not held. A multi-point video conference terminal, comprising: means for starting transmission when there is transmission data that holds and holds the right and has the transmission suspended.