JP2013201623A - Communication control device, communication system, method for controlling communication control device, program for making computer execute the control method, and communication device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To dynamically change a type of data transmitted according to a band state.SOLUTION: Processing performed by control devices constituting a remote control system includes the steps of: transmitting test data having a fixed amount of data to a server and starting measurement of a transmission time (S610); measuring a time during which a fixed amount of data are received from the server (S620); calculating a band (S630); determining a type of data to be transmitted and a transmission format (S650) when the band obtained as a result of the calculation is below a threshold value (YES in the step S640); notifying an electronic blackboard and a terminal of the determined contents (S660); transmitting data of the determined type (S670); and transmitting data according to preset communication conditions (step S680) when the band obtained as a result of the calculation is not less than the threshold value (NO in the S640 step).

Description

  The present invention relates to communication control, and more particularly to control of data transmission in a communication system.

  Conventionally, video conferencing systems are known and are provided by, for example, TANDBERG. This video conference system is also applied to the education field and is known as a distance education system. The distance learning system not only transmits handwritten characters, voices, and images, but also transmits and receives multimedia data with a large amount of information such as moving images, so that teachers and students in remote classrooms can express their facial expressions. Visible in real time. Therefore, it is possible to realize a lecture with a reality close to the conventional face-to-face (face-to-face).

  Regarding the transmission of multimedia data, for example, Japanese Patent Laid-Open No. 2002-77857 (Patent Document 1) states that “the transmission bit rate of multimedia data to be transmitted is dynamically adjusted according to the bandwidth of the network environment and viewed. It is possible to display high-quality multimedia data on a user terminal ", which discloses a multimedia data transmission device (see [Summary]).

  Japanese Patent Application Laid-Open No. 2004-320763 (Patent Document 2) states that “a wireless communication apparatus capable of minimizing degradation of video and audio data and maintaining data transmission as much as possible even when the communication state deteriorates. , A wireless AV system, a wireless transmission method, an operation control program, and a recording medium on which the program is recorded ([summary]).

  Japanese Patent Laying-Open No. 2007-208853 (Patent Document 3) discloses a transmission system that “uses communication bands of a plurality of transmission channels effectively, and prevents image quality deterioration as much as possible particularly for high-definition video transmission”. ([Summary]).

Japanese Patent Laid-Open No. 2002-77857 Japanese Patent Laid-Open No. 2004-327663 JP 2007-208553 A

  However, in an environment where the network state changes dynamically, data transfer is delayed as the state deteriorates. Conventionally, there is a technology that dynamically adjusts the transmission bit rate of multimedia data to be transmitted according to the bandwidth of the network environment. There is a case where the type is changed and a large network bandwidth control by the application is required. In particular, in the case of an application that requires interactive control in real time, such as a distance education system, control in consideration of such a band is necessary.

  Therefore, it is necessary to construct a system so that the remote communication system can be utilized smoothly by controlling the network bandwidth on the application side. Further, even in a poor network environment, it is necessary for an application to dynamically change a communication method to secure some communication means with a remote place and continue communication.

  The present invention has been made to solve the above-described problems, and an object in one aspect is to provide a communication control apparatus capable of transmitting multimedia data in accordance with network bandwidth conditions. .

  The objective in the other situation is to provide the method for controlling a communication control apparatus so that multimedia data may be transmitted according to the condition of a network band.

  Still another object of the present invention is to provide a program for causing a computer to function as a communication control device that transmits multimedia data in accordance with network bandwidth conditions.

  The communication control device according to the embodiment includes a transmission means for transmitting data to another communication device connected to the communication line, and data returned from the other communication device in response to data reception. Receiving means for receiving and control means for controlling communication by the communication control device. The transmission means is configured to transmit test data to another communication device based on the control of the control means. The receiving means is configured to receive data returned from another communication device in response to receiving the test data. The control means is configured to calculate the bandwidth of the communication line based on the time from transmission to reception of the test data and the size of the test data. The communication control device further includes a determination unit for determining the type of data transmitted using the communication line based on the bandwidth and a predefined bandwidth threshold. The transmission means is configured to transmit the type of data determined by the determination result to the communication terminal connected to the communication line.

Preferably, the transmission means is configured to transmit the determination result to the communication terminal.
Preferably, the communication control device further includes an input unit for receiving an input of image data from a photographing device connected to the communication control device. When the moving image cannot be transmitted using the communication line, the control unit is configured to acquire still images from the image data at predetermined time intervals. The transmission means is configured to transmit each still image to the communication terminal at a predetermined time interval.

  Preferably, when a plurality of still images cannot be transmitted discretely using a communication line, the transmission means performs data transmission based on a data transmission command given to the communication control device. It is configured as follows.

  Preferably, the transmission means is configured to transmit test data to another communication device after transmitting data to each communication terminal.

  Preferably, the transmission means is configured to transmit the test data to another communication device at predetermined time intervals.

  Preferably, the type of data transmitted from the communication control device to the communication terminal includes any one of a moving image, a still image, voice, handwritten characters, and text.

  According to another embodiment, a communication system is provided that includes any one of the communication control apparatuses described above and a communication terminal that can be connected to a communication line to which the communication control apparatus is connected.

  According to another embodiment, a method for controlling a communication controller is provided. The method includes a step of transmitting data to another communication device connected to a communication line, a step of receiving data returned from another communication device in response to reception of data, and a communication control device. Controlling communication. The step of transmitting includes the step of transmitting test data to another communication device. The step of receiving includes the step of receiving data returned from another communication device in response to receiving the test data. The step of controlling includes the step of calculating the bandwidth of the communication line based on the time from transmission to reception of the test data and the size of the test data. The method further includes the step of determining the type of data transmitted using the communication line based on the bandwidth and a predefined bandwidth threshold. The step of transmitting includes the step of transmitting the type of data determined by the determination result to the communication terminal connected to the communication line.

  According to another embodiment, a program for causing a computer to execute a method for controlling a communication control device is provided. The program includes a step of transmitting data to a computer to another communication device connected to the communication line, a step of receiving data returned from the other communication device in response to reception of data, and a communication control Controlling the communication by the device. The step of transmitting includes the step of transmitting test data to another communication device. The step of receiving includes the step of receiving data returned from another communication device in response to receiving the test data. The step of controlling includes the step of calculating the bandwidth of the communication line based on the time from transmission to reception of the test data and the size of the test data. The program further causes the computer to execute a step of discriminating the type of data transmitted using the communication line based on a bandwidth and a predefined bandwidth threshold. The step of transmitting includes the step of transmitting the type of data determined by the determination result to the communication terminal connected to the communication line.

  A communication device according to another embodiment includes a communication unit for communicating with another device via a communication line, and a control unit for controlling communication with the other communication. The communication means is configured to receive a status representing the status of the communication line from a communication control apparatus connected to the communication line in order to control communication between the communication apparatus and another apparatus. The control means is configured to select a data type to be communicated through the communication line from a predetermined data type based on the status, and other data of the same type as the selected data type is selected. Configured to transmit to the device.

  Preferably, the communication device further includes a monitor. When the selected data type is not the type of data that can be communicated through the communication line and the request for transmitting the selected data is given to the communication device, the control means monitors the fact that the selected data cannot be transmitted. It is configured to be displayed.

  The above and other objects, features, aspects and advantages of the present invention will become apparent from the following detailed description of the present invention taken in conjunction with the accompanying drawings.

1 is a diagram illustrating a schematic configuration of a distance education system 10. FIG. It is a block diagram showing the hardware constitutions of the computer system 200 which functions as these apparatuses. 2 is a block diagram showing a configuration of functions realized by first control device 100. FIG. FIG. 3 is a diagram conceptually illustrating one aspect of data storage in a table 330. 2 is a block diagram illustrating a hardware configuration of electronic blackboards 120 and 130. FIG. 3 is a flowchart showing a part of processing realized by control unit 300 of first control device 100. It is a figure showing the state in case a teacher provides a lesson to the student in a remote place. It is a figure showing the state in case a teacher provides a lesson to the student in a remote place. It is a figure showing an example of the screen displayed on the display panel of the electronic blackboard 120 or the terminal 140.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same parts are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

<Technology>
The technical idea according to the present embodiment is as follows. For example, the technical idea can be applied to a remote education system or a remote conference system connecting a plurality of bases. In the following, the technical idea will be described using a distance education system as an example.

  The distance learning system investigates network bandwidth information, and selects an appropriate communication method based on the investigation result. The distance learning system uses the selected communication method to transfer data (moving image, still image, voice, handwritten character, text, etc.) from a remote location, for example, from a first classroom with a teacher. Send to the second classroom where the student is.

  For example, the distance learning system dynamically changes the transmission data and the transmission method sent from the first classroom to the second classroom according to the bandwidth. For example, if the state of the communication line is such a band that cannot transmit the moving images of the first or second classroom, the distance learning system captures still images at predetermined intervals, and Data is transmitted from the first classroom to the second classroom.

  In the case where the communication line status is further narrow and the capture transmission at regular intervals is difficult, the distance learning system transmits data at the timing when the transmission button is pressed by the teacher, for example.

  When it is difficult to transmit even a still image, the distance learning system transmits only handwritten characters by the teacher as image data. More specifically, information on handwritten characters drawn on the electronic blackboard used by the teacher is transmitted to the electronic blackboard arranged in the second classroom where the students are located.

  The distance learning system confirms the current state of the communication line and displays on the electronic blackboard, tablet terminal, etc. what kind of data transmission is optimal. When the teacher confirms the information displayed on the electronic blackboard, the type of image data to be transmitted can be selected from moving images, still images, handwritten characters, text (commands), etc. according to the information. Appropriate data transmission is realized depending on the situation.

  In more detail, the control apparatus which comprises a distance education system implement | achieves data transmission according to a zone | band as follows, for example.

  Step (1) The control device included in the remote control system transmits a certain amount of test data to the server connected to the communication line, and starts measuring the transmission time. When the server receives the test data, it returns it to the control device.

  Step (2) The control device receives the test data sent from the server, and when the reception is completed, ends the measurement of the transmission time.

Step (3) The control device calculates the bandwidth as follows.
Band [bytes / s] = (data size of test data × 2) / transmission time Step (4) The control device compares the band obtained by the calculation of step (3) with a predetermined threshold value, Based on the result of the comparison, the type of data to be transmitted and the transmission method are determined in the distance learning system, and the type of data and the transmission method are determined according to the determination content.

  Step (5) The control device uses the result obtained in step (4) as a status indicating the transmission status in the distance learning system, and all electronic blackboards, electronic blackboard control devices, electronic blackboards or Notify a tablet terminal or other communication device that can communicate with the control device.

  Step (6) Each communication device that has received the notification selects a data reception method and transmission method according to the status. Thereafter, each communication apparatus acquires data that can be transmitted according to the selection result, and transmits such data to the transmission partner. Therefore, for example, when the status indicates that only handwritten characters can be transmitted as image data, even if a student who is a user of the tablet terminal tries to transmit a still image, the tablet terminal Is not transmitted, and a message that such transmission is not possible is displayed.

<System configuration>
Next, with reference to FIG. 1, the structure of the distance education system 10 which concerns on this Embodiment is demonstrated. FIG. 1 is a diagram illustrating a schematic configuration of a distance education system 10.

  The distance learning system 10 includes a server 110, a first control device 100, an electronic blackboard 120, a microphone 121, a camera 122, a speaker 123, a second control device 101, an electronic blackboard 130, a microphone 131, A camera 132, a speaker 133, and terminals 141, 142, and 143 are provided. The terminals 141, 142, and 143 are collectively referred to as a terminal 140.

  The first control device 100, the second control device 101, and the server 110 are each connected to the Internet 150. The first control device 100, the microphone 121, the camera 122, and the speaker 123 are connected to the electronic blackboard 120, respectively. The second control device 101, the microphone 131, the camera 132, and the speaker 133 are connected to the electronic blackboard 130, respectively.

  The first control device 100, the electronic blackboard 120, the microphone 121, the camera 122, and the speaker 123 are arranged in the first classroom. The second control device 101, the electronic blackboard 130, the microphone 131, the camera 132, the speaker 133, and the terminals 141, 142, 143 are arranged in the second classroom. The second classroom exists in a remote place from the first classroom. For example, the first classroom is located in a city and the second classroom is located in a suburb.

  The first control device 100, the server 110, and the second control device 101 can communicate with each other. Each of the terminals 141, 142, and 143 can communicate with the second control device 101 by wireless communication.

  In one aspect, the electronic blackboard 120 is used by a teacher. The teacher is photographed by the camera 122. The teacher's utterance content is collected by the microphone 121. The speaker 123 outputs the sound from the microphone 131 that picks up the sound of the student in the remote place. When the teacher writes characters, graphics, and the like on the electronic blackboard 120, the written content is transmitted to the second control device 101 by the first control device 100. The second control device 101 transmits the contents to the electronic blackboard 130. The electronic blackboard 130 displays the contents written on the electronic blackboard 120. The content of the teacher's utterance is output from the speaker 133.

  In a remote place, each student has terminals 141, 142, and 143, respectively. Each terminal 140 can display the contents written on the electronic blackboard 120 as with the electronic blackboard 130. The contents handwritten by each student to the terminal 140 are transmitted to the electronic blackboard 130 and the electronic blackboard 120 used by the teacher via the second control device.

  The state of each student is photographed by the camera 132. The content of the student's utterance is converted into an electric signal by the microphone 131, sent from the electronic blackboard 130 to the second control device 101 and the first control device 100, and output from the speaker 123. The state of each student is photographed by the camera 132. Image data obtained by shooting is transmitted through the same path as the audio signal. When the electronic blackboard 120 receives the data, it displays the state of the student.

<Hardware configuration>
With reference to FIG. 2, the structure of the 1st control apparatus 100 which concerns on this Embodiment, the 2nd control apparatus 101, and the server 110 is demonstrated. FIG. 2 is a block diagram showing the hardware configuration of a computer system 200 that functions as these devices.

  The computer system 200 is generated by a CPU (Central Processing Unit) 1 that executes a program, a mouse 2 and a keyboard 3 that receive an instruction input by a user of the computer system 200, and execution of the program by the CPU 1 as main components. A RAM 4 that stores data or data input via the mouse 2 or the keyboard 3 in a volatile manner, a hard disk 5 that stores data in a nonvolatile manner, an optical disk drive device 6, a communication IF (Interface) 7, and a monitor 8. Each component is connected to each other by a bus. A CD-ROM 9 and other optical disks are mounted on the optical disk drive 6. The communication IF 7 includes, but is not limited to, a USB (Universal Serial Bus) interface, a wired LAN (Local Area Network), a wireless LAN, and a Bluetooth (registered trademark) interface.

  The processing in the computer system 200 is realized by each hardware and software executed by the CPU 1. Such software may be stored in the hard disk 5 in advance. The software may be stored in a CD-ROM 9 or other non-volatile computer-readable data recording medium and distributed as a program product. Alternatively, the software may be provided as a program product that can be downloaded by an information provider connected to the Internet or other networks. Such software is read from the data recording medium by the optical disk drive 6 or other data reading device, or downloaded via the communication IF 7 and then temporarily stored in the hard disk 5. The software is read from the hard disk 5 by the CPU 1 and stored in the RAM 4 in the form of an executable program. The CPU 1 executes the program.

  Each component constituting the computer system 200 shown in FIG. 2 is general. Therefore, it can be said that the most essential part according to the present embodiment is a program stored in the computer system 200. Since the operation of each hardware of computer system 200 is well known, detailed description will not be repeated.

  The data recording medium is not limited to a CD-ROM, FD (Flexible Disk), and hard disk, but is a magnetic tape, cassette tape, optical disk (MO (Magnetic Optical Disc) / MD (Mini Disc) / DVD (Digital Versatile Disc)). ), IC (Integrated Circuit) card (including memory card), optical card, mask ROM, EPROM (Electronically Programmable Read-Only Memory), EEPROM (Electronically Erasable Programmable Read-Only Memory), flash ROM, etc. It may be a non-volatile data recording medium that carries a fixed program.

  The program here may include not only a program directly executable by the CPU but also a program in a source program format, a compressed program, an encrypted program, and the like.

<Functional configuration>
With reference to FIG. 3, the structure of the 1st control apparatus 100 which concerns on this Embodiment is demonstrated. FIG. 3 is a block diagram showing a configuration of functions realized by first control device 100. The configuration of the first control device 100 will be described below, but the same applies to the second control device 101. The distance learning system 10 only needs to have a configuration for realizing the following functions in at least one of the first control device 100 and the second control device 101.

  The first control device 100 includes a network bandwidth detection unit 310, a data type selection unit 320, a table 330, a control unit 300, a data reception unit 340, a data transmission unit 350, a display unit 360, and a video capture 370. Voice data 380 and an input command 390.

  The control unit 300 controls communication by the first control device 100. For example, the control unit 300 detects the state of the network band in the distance learning system 10 and realizes data transmission according to the state.

  Based on the control by the control unit 300, the network band detection unit 310 detects the network band of the distance learning system 10, more specifically, for example, the network band between the first control device 100 and the second control device 101. To do. In one aspect, the network bandwidth detection unit 310 transmits test data from the first control device 100 to the server 110 and performs first control from the server 110 as described in the above steps (1) to (3). The time until it is returned to the apparatus 100 is measured. The network band detection unit 310 calculates the network band based on the size of the test data and the measured time. In another aspect, the network bandwidth detection unit 310 may calculate the bandwidth by transmitting test data from the first control device to the second control device.

  The data type selection unit 320 selects the type of data transmitted in the distance learning system 10 while referring to the table 330 based on the detection result by the network band detection unit 310. For example, the data type selection unit 320 selects the data type having the largest threshold associated with the data type from among the data types that do not exceed the bandwidth calculated by the network bandwidth detection unit 310. Data belonging to the selected data type is a transmission target.

  The table 330 includes data for determining the band and the type of transmission data. The structure of the table 330 will be described with reference to FIG.

  The data receiving unit 340 receives data from the outside of the first control device 100, specifically, from the electronic blackboard 120 or the Internet 150.

  The data transmission unit 350 transmits data to the outside of the first control device 100. Specifically, in a certain aspect, the first control device 100 transmits data received via the Internet 150 to the electronic blackboard 120. In another aspect, the data transmission unit 350 transmits data to the server 110 or the second control device 101 via the Internet 150.

  The display unit 360 displays the state of the first control device 100 or information detected in the first control device 100 based on the control of the control unit 300. The state is, for example, a state of communication between the first control device 100 and another control device. The information includes, for example, a screen showing the state of the network bandwidth in the distance learning system 10, for example, whether the bandwidth is wide or narrow.

  Video capture 370 includes, for example, a teacher's image taken by camera 122. The audio data 380 includes teacher utterance contents collected by the microphone 121.

  The input command 390 includes a command corresponding to an operation input to the electronic blackboard 120 by the teacher. For example, when the teacher writes a character on the electronic blackboard 120, the input command 390 includes a command indicating that the following input is a character input by handwriting. In another aspect, input command 390 includes a command for displaying a predetermined character on electronic blackboard 130, for example.

<Details of functional configuration>
In an aspect, the data transmission unit 350 of the first control device 100 transmits test data to the server 110 based on the control of the control unit 300. When the server 110 receives the test data, it returns it to the first control device 100. The data receiving unit 340 receives data returned from the server 110 in response to receiving test data. The control unit 300 calculates the bandwidth of the Internet 150 based on the time from transmission to reception of test data and the size of the test data. As a determination unit, the control unit 300 determines the type of data transmitted using the Internet 150 based on a bandwidth obtained by calculation and a predefined bandwidth threshold. The data type selection unit 320 determines the type of data transmitted from the first control device 100 to the second control device 101 based on the determination result. The data transmission unit 350 transmits the type of data determined by the determination result to the second control apparatus 101 based on the control of the control unit 300.

  In another aspect, data transmission unit 350 transmits the determination result to second control apparatus 101.

  In another aspect, the video capture 370 receives input of image data from the camera 122. When the moving image cannot be transmitted using the Internet 150, the control unit 300 acquires still images from the image data at predetermined time intervals via the video capture 370. The data transmission unit 350 transmits each still image to the communication terminal at a predetermined time interval.

  In another aspect, when a plurality of still images cannot be transmitted discretely using the Internet 150, the data transmission unit 350 is based on the fact that a data transmission command is given to the first control device 100. Data transmission. Here, discrete transmission means that data transmission is performed discontinuously, for example, transmission at regular time intervals. The data transmission command is given by an operation of a user (for example, a teacher or an administrator) of the electronic blackboard 120, for example.

  In another aspect, the data transmission unit 350 newly transmits test data to the server 110 after transmitting data to the second control apparatus 101. Thereby, the first control apparatus 100 can confirm the data transmission status on the Internet 150 “sequentially”. Therefore, even if the status of the communication line on the Internet 150 changes significantly, the distance learning system 10 according to the present embodiment can quickly respond to the change in the status.

  In another aspect, data transmission unit 350 transmits test data to server 110 at predetermined time intervals. As a result, the first control apparatus 100 can check the data transmission status on the Internet 150 “periodically”, so the distance education system 10 can periodically review the type of data to be transmitted. .

  In the above description, the case where the first control device 100 transmits the test data to the server 110 has been described. However, the test data may be transmitted from the first control device 100 to the second control device. Further, the second control device 101 may transmit test data to the server 110 or the first control device 100.

  In the present embodiment, the types of image data transmitted from the first control device 100 to the second control device 101 or from the second control device 101 to the first control device 100 are illustratively moving images and still images. , Including voice, handwritten text, or text. The data to be transmitted is not limited to these, and other electronic data may be transmitted.

  With regard to data transmitted from the first control device 100 to the second control device 101, for example, a moving image is, for example, an image obtained by photographing an explanation by a teacher. The still image is an image obtained by photographing the content written on the electronic blackboard 120 by the teacher. The voice is the content of the teacher's utterance. The handwritten character is a character drawn on the electronic blackboard 120 and includes, for example, an assignment for a student. The text is, for example, a command output by the electronic blackboard 120 when the teacher touches the electronic blackboard 120 or a text character that the teacher inputs to the electronic blackboard 120 through a keyboard operation.

  On the other hand, regarding the data transmitted from the second control device 101 to the first control device 100, the moving image is, for example, a video obtained by photographing a student. The still image is an image obtained by photographing of the student or an image input to the terminals 141, 142, and 143 used by the student. The voice is a student's answer to the teacher's question or a student's question to the teacher. The handwritten character is a sentence, a question, or the like input to the terminals 141, 142, and 143 by each student. The command is sent to the first control device 100 in response to an operation on the terminals 141, 142, and 143 by the student. The command is, for example, a signal or schedule when the student leaves the classroom.

<Data structure>
With reference to FIG. 4, the data structure of first control apparatus 100 according to the present embodiment will be described. FIG. 4 is a diagram conceptually showing one mode of data storage in table 330.

  The table 330 includes a transmission target 410 and a necessary bandwidth 420. The transmission target 410 includes, for example, moving images, still images, sounds, handwritten characters, commands, and the like as types of data to be transmitted. Items other than the items shown in FIG. 4 may be defined as the transmission target 410.

  The necessary band 420 is a band that is defined in advance for each of the transmission targets 410. For example, it is determined by the administrator of the distance learning system 10 before the operation of the distance learning system 10 according to the situation where the distance learning system 10 is used. This band may be changed by the user of the first control apparatus 100.

<Electronic blackboard>
With reference to FIG. 5, the structure of the electronic blackboards 120 and 130 according to the present embodiment will be described. FIG. 5 is a block diagram showing a hardware configuration of the electronic blackboards 120 and 130.

  The electronic blackboards 120 and 130 include a processor 510, a memory 520, a communication interface 530, a user interface 540, and a display panel 550.

  The processor 510 controls the operation of the electronic blackboards 120 and 130 based on a command given to the electronic blackboards 120 and 130 or based on a predetermined condition being satisfied.

  The memory 520 stores data and a program for executing processing specified in advance on the electronic blackboards 120 and 130. The memory 520 stores data generated by the processor 510 or data input via the communication interface 530 or the user interface 540.

  The communication interface 530 communicates with a control device (that is, the first control device 100 or the second control device 101) to which the electronic blackboards 120 and 130 are coupled.

  The user interface 540 receives input to the electronic blackboards 120 and 130. For example, the user interface 540 is realized as a touch panel provided in the display area and a hard switch provided in the outer frame of the casing.

  Display panel 550 displays a screen based on the data sent from processor 510. The displayed screen includes, for example, image data, characters, graphics and the like sent from another electronic blackboard. Note that the display panel 550 may display a plurality of screens. For example, when the bandwidth in the distance education system 10 is sufficient, the display panel 550 may display a moving image or a still image and handwritten characters side by side.

<Control structure>
With reference to FIG. 6, the control structure of first control apparatus 100 according to the present embodiment will be described. FIG. 6 is a flowchart showing a part of processing realized by the control unit 300 of the first control apparatus 100.

  In step S610, control unit 300 transmits test data having a predetermined data amount set in advance to server 110, and starts measuring transmission time.

  In step S620, when control unit 300 receives a signal notifying completion of reception of test data from data reception unit 340, control unit 300 determines the time required for transmission / reception of test data between first control device 100 and server 110. measure.

  In step S630, control unit 300 calculates a bandwidth between first control device 100 and server 110 based on the data amount of the transmitted test data and the measured time. As the calculation formula, for example, the formula shown in step (3) is used.

  In step S640, control unit 300 determines whether or not the calculated value obtained in step S630 is less than a predetermined threshold value. If it is determined that the calculated value is less than the threshold value (YES in step S640), the control unit switches control to step S650. If not (NO in step S640), control unit 300 switches control to step S680.

  In step S650, control unit 300 refers to table 330 to determine the type of data to be transmitted and the transmission format of the data. For example, the control unit 300 selects the type of data having the largest band among the necessary bands 420 while comparing the necessary band 420 with the band obtained by calculation.

  In step S660, the control unit 300 notifies the contents determined in step S650 to the processor 510 of the electronic blackboards 120 and 130 and the terminals 141, 142, and 143, respectively.

  In step S670, control unit 300 communicates data of the type determined as a transmission target with server 110, terminals 141, 142, 143, and second control device 101. For example, when a moving image is determined as a transmission target, the control unit 300 of the first control device 100 performs streaming transmission of moving image data to the second control device 101. When the still image is determined as a transmission target, the control unit 300 transmits the still image to the second control apparatus 101 at predetermined time intervals. When a handwritten character is selected as a transmission target, the control unit 300, when a command for notifying the end of input of the handwritten character is given to the electronic blackboard 120, the information about the input handwritten character is displayed on the second control device 101. Send to. When the text or command is selected as a transmission target, the control unit 300 sends the text or command to the second control device 101 when an operation for confirming the input of the text or command is given to the electronic blackboard 120. Send.

  In step S680, control unit 300 performs data communication with server 110, terminals 141, 142, 143, and second control apparatus 101 under preset communication conditions. The communication condition includes, for example, a transmission priority order associated with each data type. In this case, since there is room in the band, the control unit 300 transmits a moving image, a still image, voice, handwritten characters, text, and the like to the second control device 101 according to the communication conditions.

  The determination in step S640 may be whether or not the calculated value is equal to or less than a predetermined threshold value in another aspect.

<Operation>
With reference to FIG. 7 and FIG. 8, operation | movement of the distance education system 10 which concerns on this Embodiment is demonstrated. FIG. 7 and FIG. 8 are diagrams each showing a state where a teacher provides a lesson to a student at a remote place.

  Referring to FIG. 7, in one aspect, when there is a sufficient bandwidth of distance learning system 10, moving image data and audio data are transmitted in distance learning system 10. Specifically, the teacher 710 writes handwritten characters 730 on the electronic blackboard 120. The teacher 710 also utters the utterance 720 toward the microphone 121. The handwritten character 730 is sent to the second control device 101 via the first control device 100 and the Internet 150 and further displayed on the electronic blackboard 130 as the handwritten character 731.

  The figure of the teacher 710 is taken by the camera 122 and sent from the first control device 100 to the electronic blackboard 130 as moving image data. Since the electronic blackboard 130 displays the appearance of the teacher 710 as an image 741, the student can visually recognize the teacher 710 with the image.

  The utterance 720 is collected by the microphone 121, and the voice data is transmitted from the first control device 100 to the second control device 101. When the speaker 133 outputs sound, the student can hear the contents of the teacher's utterance 720.

  On the other hand, the students 741, 742, and 743 use terminals 141, 142, and 143 at remote locations, respectively. Terminals 141, 142, and 143 display images 732, 733, and 734 respectively corresponding to handwritten characters 730 written by the teacher. The utterance contents of the students 741, 742, and 743 are collected by the microphone 131, transmitted as an audio signal, and output from the speaker 123. The teacher 710 can listen to the comments of the students 741, 742, and 743.

  Referring to FIG. 8, when the bandwidth of distance learning system 10 is narrowed thereafter, for example, moving image transmission is not performed. Accordingly, the image 741 or the student image 750 as shown in FIG. 7 is not displayed on the electronic blackboard 130 and the electronic blackboard 120, respectively. At this time, the handwritten character 730 is transmitted and displayed as images 732, 733, and 734 on the terminals 141, 142, and 143, respectively. Accordingly, the students 741, 742, and 743 can know the contents of the electronic blackboard 120.

  In this way, since the type of data transmitted in the distance learning system 10 changes according to the band condition, a delay in transmission due to a change in the band state, particularly a change from the wide band to the narrow band, is prevented. In this way, even if a moving image that requires a wide band is temporarily not transmitted, alternative data such as a still image, voice, and handwritten characters is transmitted. The interruption of education by is prevented.

<Display mode>
With reference to FIG. 9, the display mode of the screens of electronic blackboards 120 and 140 according to the present embodiment will be described. FIG. 9 is a diagram illustrating an example of a screen displayed on the display panel of the electronic blackboard 120 or the terminal 140.

  As shown in state A, when the bandwidth is sufficient in the distance learning system 10, the display panel can transmit all of moving images, still images, sounds, handwritten characters, texts, or commands (OK). ) Is displayed. The first control device 100 appropriately checks the bandwidth during transmission.

  As shown in the state B, when the band is narrowed to such an extent that the moving image data cannot be transmitted thereafter, the display panel indicates that the moving image cannot be transmitted (NG), and the still image, voice, handwritten character, and text or A message indicating that the command can be transmitted (OK) is displayed. The first control device 100 appropriately checks the bandwidth during transmission.

  As shown in the state C, when the band state further deteriorates, the display panel can transmit the moving image and the still image (NG) and can transmit the voice, the handwritten character, and the text or the command. “OK” is displayed. The first control device 100 appropriately checks the bandwidth during transmission. After that, if the bandwidth is sufficiently recovered, as shown in the state A, a message (OK) indicating that a moving image and a still image can be transmitted is displayed.

<Effect of embodiment>
As described above, according to the distance learning system 10 according to the present embodiment, the type of data to be transmitted is determined according to the bandwidth of the network where the data is transmitted. That is, when a sufficient band is secured, content data with a large amount of data such as a moving image is transmitted. When the bandwidth is insufficient, content data with a small amount of data such as a still image (capture image), handwritten characters, and text string is transmitted. Therefore, since it becomes difficult for a two-way communication failure due to lack of bandwidth to occur, a class delay due to a transmission delay can be prevented.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  1 CPU, 2 mouse, 3 keyboard, 4 RAM, 5 hard disk, 6 optical disk drive device, 7 communication IF, 8 monitor, 9 ROM, 10 remote education system, 100 first control device, 101 second control device, 110 server, 120, 130 Electronic blackboard, 121, 131 Microphone, 122, 132 Camera, 123, 133 Speaker, 141, 142, 143 Terminal, 150 Internet, 200 Computer system, 300 Control unit, 310 Network band detection unit, 320 Data type selection unit 330 table, 340 data receiving unit, 350 data transmitting unit, 360 display unit, 370 video capture, 380 audio data, 390 input command, 510 processor, 520 memory, 530 communication interface, 5 0 user interface 550 display panel, 710 teachers, 720 utterance, 730 and 731 handwritten character, 732,733,734 images, 741,750 images, 741,742,743 students.

Claims (12)

A communication control device,
A transmission means for transmitting data to other communication devices connected to the communication line;
Receiving means for receiving data via the communication line;
Control means for controlling communication by the communication control device,
The transmission means is configured to transmit test data to the other communication device based on the control of the control means,
The receiving means is configured to receive data returned from the other communication device in response to the reception of the test data;
The control means is configured to calculate a bandwidth of the communication line based on a time from transmission to reception of the test data and a size of the test data,
The communication control device further includes:
Based on the bandwidth and a predefined bandwidth threshold, comprising a determination means for determining the type of data transmitted using the communication line,
The communication control device configured to transmit the type of data determined by the determination result to a communication terminal connected to the communication line.   The communication control apparatus according to claim 1, wherein the transmission unit is configured to transmit a result of the determination to the communication terminal. Further comprising input means for receiving input of image data from a photographing device connected to the communication control device;
When the moving image cannot be transmitted using the communication line, the control means is configured to acquire still images at predetermined time intervals from the image data,
The communication control apparatus according to claim 1, wherein the transmission unit is configured to transmit each of the still images to the communication terminal at a predetermined time interval.   When a plurality of still images cannot be transmitted discretely using the communication line, the transmission means performs data transmission based on a data transmission command given to the communication control device. The communication control device according to claim 3, configured as described above.   The communication according to any one of claims 1 to 4, wherein the transmission unit is configured to transmit the test data to the other communication device after transmitting data to the communication terminal. Control device.   The communication control device according to any one of claims 1 to 4, wherein the transmission unit is configured to transmit the test data to the other communication device at predetermined time intervals.   The communication control apparatus according to any one of claims 1 to 6, wherein the type of data transmitted from the communication control apparatus to the communication terminal includes any one of a moving image, a still image, a voice, a handwritten character, and a text. The communication control device according to any one of claims 1 to 7,
A communication system comprising: a communication terminal connectable to a communication line to which the communication control device is connected. A method for controlling a communication control device, comprising:
Transmitting data to other communication devices connected to the communication line;
Receiving data returned from the other communication device in response to reception of the data;
Controlling communication by the communication control device,
The step of transmitting includes the step of transmitting test data to the other communication device,
The receiving step includes receiving data returned from the other communication device in response to the reception of the test data;
The controlling step includes a step of calculating a bandwidth of the communication line based on a time from transmission to reception of the test data and a size of the test data,
The method further comprises:
Determining the type of data transmitted using the communication line based on the bandwidth and a predefined bandwidth threshold;
The method for controlling a communication control device, wherein the transmitting step includes a step of transmitting data of a type determined by the determination result to a communication terminal connected to the communication line. A program for causing a computer to execute a method for controlling a communication control device, wherein the program is
Transmitting data to other communication devices connected to the communication line;
Receiving data returned from the other communication device in response to reception of the data;
Controlling communication by the communication control device,
The step of transmitting includes the step of transmitting test data to the other communication device,
The receiving step includes receiving data returned from the other communication device in response to the reception of the test data;
The controlling step includes a step of calculating a bandwidth of the communication line based on a time from transmission to reception of the test data and a size of the test data,
The program is further stored in the computer.
Determining the type of data transmitted using the communication line based on the bandwidth and a predefined bandwidth threshold;
The transmitting step includes a step of transmitting the type of data determined by the determination result to a communication terminal connected to the communication line. A communication device,
A communication means for communicating with another device via a communication line;
Control means for controlling communication with the other communication,
The communication means is configured to receive a status representing a state of the communication line from a communication control apparatus connected to the communication line in order to control communication between the communication apparatus and the other apparatus. Has been
The control means includes
Based on the status, the type of data communicated on the communication line is configured to be selected from a predetermined type of data,
A communication device configured to transmit data of the same type as the selected data type to the other device. A monitor,
When the request for transmitting the selected data is given to the communication device when the selected data type is not the type of data that can be communicated on the communication line, the control means transmits the selected data. The communication device according to claim 11, wherein the communication device is configured to display on the monitor that it cannot be performed.

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