JP2009272690A - Communication system and remote language learning system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a communication system for bidirectionally transmitting/receiving a video signal and an audio signal, which achieve transmission/reception of high quality even at a low bit rate by narrowing a band of a signal. <P>SOLUTION: In the communication system for bidirectionally transmitting/receiving a video signal and an audio signal between terminals via a server and a communication line, the server connects a communication source terminal and a communication destination terminal by using a protocol which is not based on SIP (session initiation protocol) and has an automatic sound restoration function to bidirectionally transmit/receive the video signal and the audio signal. Since communication narrowing a band independently of rules of the SIP can be performed and omission of packeted sound data can be also repaired, the quality of sound communication can be improved. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a communication system for bidirectional transmission / reception of video signals and audio signals between electronic terminals such as mobile phones and personal computers, and a remote language learning system using the communication system.

  2. Description of the Related Art In recent years, a technology for two-way communication of audio and video using a mobile phone or a personal computer has been put into practical use, and VoIP technology for performing voice communication over an IP (Internet Protocol) network even for a conventional fixed phone. With the spread of Internet, mutual communication with a general public telephone network has become possible. In particular, the telephone service provided using IP of the packet communication protocol used on the Internet is called IP telephone, and after converting voice into digital data with a telephone and dividing it into units called packets, This is a system for making a voice call by sending it to the other party on the IP network. It is a system that can communicate not only voice but also video.

  As a signaling protocol for establishing an incoming / outgoing call and establishing a call using an IP network, a protocol conforming to the SIP (Session Initiation Protocol) from the conventional ITU-T recommendation H.323 standard (SIP For details, see Non-Patent Document 1, for example.) Since SIP is a protocol that is considered to be used on the Internet, it has a high affinity with the Internet, and is a video phone and real-time between multiple points. The present invention can be applied to various systems such as a conference system and a voice application linked with WEB (see, for example, Patent Document 1).

JP 2006-245655 A IETF, RFC3261 "SIP: Session Initiation Protocol", IETF, June 2002, [Search April 14, 2008], Internet <URL: http://www.ietf.org/rfc/rfc3261.txt>

  By the way, it is not easy to transmit and receive moving images in two directions in real time using a mobile phone or a personal computer even in a network capable of large-capacity communication using an optical fiber or the like because of bandwidth and bit rate. Currently. For example, in the standard of the conventional ITU-T recommendation H.323, a very large capacity is required in an indirect part in order to connect a video signal and other data communication in addition to an audio signal. In spite of not being used directly, a large bandwidth and a high bit rate are required for communication. In addition, SIP, which is being standardized instead of the conventional ITU-T recommendation H.323, is also necessary because it is a call control protocol used in various applications as well as IP telephones and video conference systems. The bit rate is about 24 kbps, and in order to establish two-way video communication, the bit rate is not yet low enough in terms of server capacity, and the quality of audio transmission is sufficiently high. The situation is not guaranteed.

  Especially when trying to use an existing communication system as a communication means for learning English and other foreign languages such as so-called video conference between teachers and students, within a limited transmission rate. Emphasis on the characteristics of moving images and the like tends to lower the quality of audio data, and the lack of packetized audio data makes the content that Japanese should master, such as pronunciation, unclear.

  In view of the above technical problems, the present invention has an object to provide a communication system that bidirectionally transmits and receives a video signal and an audio signal that realizes high-quality transmission / reception even at a low bit rate by narrowing a signal band. And Another object of the present invention is to provide a remote language learning system that performs bidirectional communication using such a communication system.

  In order to solve the above technical problem, the communication system of the present invention is a communication system that bidirectionally transmits and receives video signals and audio signals between terminals via a server and a communication line, and is based on SIP (Session Initiation Protocol). Using a protocol that is not compliant and has an automatic audio restoration function, the server connects a communication source terminal and a communication destination terminal, and bi-directionally transmits and receives a video signal and an audio signal. .

  In addition, the distance learning system of the present invention that solves the above technical problem uses a protocol that is compliant or non-compliant with SIP (Session Initiation Protocol) and has an automatic voice restoration function, and the server is a communication source terminal. The video and audio signals are transmitted and received bidirectionally by connecting the communication terminal and the communication destination terminal via a communication line, and the language learner operates one terminal while the language instructor operates the other terminal. It is characterized by learning language.

  According to the communication system of the present invention, since a protocol that is not compliant with SIP and has a voice automatic restoration function is used, communication with a narrow band can be performed without being bound by the SIP protocol and packetized. Since missing voice data can also be repaired, the quality of voice communication can be improved and is particularly suitable for applications such as language learning.

  The communication system and remote language learning system of the present invention will be described below with reference to the drawings. The communication system according to the embodiment of the present invention can connect terminals such as a mobile phone and a personal computer to each other via a network server, and is particularly suitable as a communication means for acquiring a language such as a foreign language. is there.

  FIG. 1 is a schematic diagram of a remote language learning system according to the present embodiment, in which one terminal is operated by a language learner and the other terminal is operated by a language instructor. Here, one terminal operated by the language learner is through a mobile phone 21 according to the so-called third generation mobile standard, a personal computer 22 connected as a peripheral device with a microphone, a speaker, a digital camera, etc., and a router 29. Various electronic devices such as an earset 28 wirelessly connected from a connected robot 25 or an electronic device 26 such as a set top box via a Bluetooth (registered trademark) connection device 27 can be used as a terminal. In the example, the remote language learning system of this embodiment is depicted as being connected one by one as a terminal, but a plurality of terminals can be connected via the Internet 30 or the like.

  The mobile phone 21 is an electronic terminal that employs a WCDMA (Wideband CDMA: code division multiple access) method, which is a so-called third generation mobile phone communication method, and a base station 31 of a predetermined mobile phone carrier. Performs predetermined data communication and exchanges information. The personal computer 22 is a device connected to the Internet 30 and capable of inputting and outputting voice and moving images. In order to realize the remote language learning system of this embodiment, the personal computer 22 is used for a remote language learning system on a predetermined OS. A dedicated application is executed. In the personal computer 22, a microphone as an audio input unit and a speaker as an audio output unit are connected to a predetermined audio input / output terminal, and a headset can be connected instead of the microphone and the speaker. A monitor of the personal computer 22 is used as video output means, and a digital camera is connected as video input means in the form of being connected to a USB terminal of the personal computer 22, for example. A wired earset 24 connected via the USB terminal 23 can also be connected to the personal computer 22.

  The robot 25 connected via the router 29 is an electronic device having a microphone and a speaker. The robot 25 is connected to the router 29 connected to the Internet 30 by a wireless connection such as a WiFi (registered trademark) connection. To do. Specifically, the robot 25 is composed of a pedestal part with a built-in speaker and an animal toy part that operates in response to a signal. The robot 25 can be lit with an LED or the like during a call, and functions as a clock. May be provided. By speaking to the animal toy part of the robot 25, the voice of the student is converted into an electrical signal and sent to the network server 10.

  For example, a set-top box type electronic device 26 connected to a cable network or the like is connected to the Internet 30 via the cable network and can output audio and video while using a television receiver as a monitor. A connection device 27 is connected to the electronic device 26 as a peripheral device for wireless connection by the Bluetooth (registered trademark) system, and an earset 28 is connected via the connection device 27.

  The above shows each terminal on the side operated by the language learner, but the other terminal operated by the language instructor is, for example, a plurality of personal computers 11 arranged in a call center, and each inputs voice. For example, a digital camera for inputting video, and the like. As a call center, there is no particular need to limit it to domestic. For example, if you want to learn English as a foreign language, you can learn a foreign language by setting up a call center in an English-speaking country, for example, in a university or other institution. The environment will be further improved. Further, the terminal on the language instructor side is not limited to the personal computer installed in the call center, and for example, a personal computer at the home of the language instructor or a mobile phone can be used.

  The network server 10 is a device for connecting terminals via the Internet 30 and a mobile phone carrier base station. In particular, in the remote language learning system of this embodiment, video signals and audio signals are bidirectionally transmitted and received between terminals using a protocol that is compliant or non-compliant with SIP (Session Initiation Protocol) and has an automatic audio restoration function. be able to.

  Here, the SL protocol used in the distance learning system of this embodiment will be described with reference to FIG. 2. A connection / disconnect signal, TTL (Time To Live) between callers. ) Signal, DTMF (Dual-Tone Multi-Frequency) signal, HANGUP signal and media signal. Specifically, the SL protocol uses G.723.1, which is a recommendation of the ITU-T voice coding system for voice. Silent parts that do not speak are silent compression that does not transmit data, or error correction codes for wireless applications. Also, a transmission code that increases bit error resistance is assigned. For example, when packet loss of voice data occurs in the middle of transmission, according to the remote language learning system of this embodiment, there is an automatic voice restoration function by restoring packet data, and the voice data quality is improved. Can be maintained.

  In addition, the SL protocol used in the remote language learning system according to the present embodiment adopts a modified RTP (Real-time Transport Protocol) as a transmission protocol, and is not particularly compliant with SIP (Session Initiation Protocol) as an example. . By making non-compliant with SIP, there is a side that devices other than the original SL protocol cannot be connected. In general, however, SIP transmission requires at least 24 kbps, and only about 8 kbps is required. Compared with the SL protocol used in the distance learning system, a much higher line capacity is required. In other words, there is an advantage that more sessions can be established within a limited communication capacity by using the remote language learning system of this embodiment. SIP or H.264 A general-purpose protocol such as H.323 emphasizes extensibility to cope with various media, and accordingly, the overhead increases accordingly and the effective bit rate is reduced. On the other hand, in the SL protocol used in the distance learning system of this embodiment, the effective bit rate is improved by reducing the overhead without selecting the extensibility. For this reason, it is a protocol form with an emphasis on voice quality, and is suitable for language learning.

  The media signal includes a header area and a data area. The header area has a data structure including a len function (len), a destination channel number (destCH), and a frame sequence number (frameseq #). For example, a channel number from 0 to 255 is designated for the destination channel number (destCH), and a number from 0x0001 to 0xffff is given as the frame sequence number (frameseq #). . Furthermore, as a remote language learning system of the present invention, a protocol conforming to SIP (Session Initiation Protocol) can be adopted. In this case, a system using a general-purpose chip or the like can be created, There is an advantage that it can be made inexpensive.

  Next, a usage pattern of the remote language learning system of the present embodiment will be described with reference to the drawings. In the remote language learning system of this embodiment, the user can register the user while operating an electronic device such as a personal computer or a mobile phone, and can apply for a level test or make a class reservation. it can. Students can also prepare for classes, cancel reservations, listen to lessons received, submit compositions and receive corrected texts. In addition, language learning in an electronic conference format in which a plurality of users attend at the same time is also possible. Hereinafter, usage forms of the remote language learning system according to the present embodiment will be sequentially described using a GUI (Graphic User Interface).

  First, a user installs dedicated communication software on an electronic device such as a personal computer or a mobile phone. For the installation of the dedicated communication software, which is this application, a disk storage device such as a CD-ROM, a USB memory device, or the like can be used, or it can be downloaded from the Internet using a communication line. For user registration, for example, a registration screen as shown in FIG. 3 is displayed on the monitor of the electronic device, and the registration start button 41 is clicked with a mouse or the like.

  This registration screen is a portal screen of the remote language learning system of the present embodiment. In addition, a basic information linked to a basic information management screen for information box 42 for posting information related to the system and basic information management. A management button 43, a telephone number setting button 44 linked to a telephone number setting screen for setting a telephone number, a credit charge button 45 linked to a credit charge screen for managing credit card information, etc., and an online phonebook An online phone book button 46 linked to the screen and a logout button 47 for logging out are provided, and predetermined data setting or the like can be performed by these operations.

  When the registration start button 41 is clicked with a mouse or the like in FIG. 3, the personal information setting screen shown in FIG. 4 appears on the monitor. In the personal information setting screen, the GUI is used to input information that also serves as a level test application. As a data input, a name input box 49 for inputting the name of a language learner who is a user, A nickname input box 50 for registering a nickname to be used, a birth date input box 51 for inputting the birth date of a language learner, and radio buttons 52 and 53 for inputting a gender are provided. The language learner who makes an application inputs predetermined data in these boxes 49, 50, 51 and buttons 52, 53. After entering the data, click the Apply button to apply for a level test. These data are transmitted to the network server 10 from a terminal composed of an electronic device such as a personal computer or a mobile phone, and stored in a storage part such as a hard disk device of the network server 10.

  When the application for the level test is accepted, the network server 10 displays that the application for the level test has been made to each of the plurality of personal computers 11 in the call center on the instructor side. On the other hand, on the applicant's terminal, for example, a screen as shown in FIG. 5 is displayed on the monitor of the terminal, indicating that the application for the level test has been accepted and notes regarding the test. In response to the level test application, a lecturer is assigned in accordance with the level test reservation while looking at the personal computer 11 in the call center. When the scheduled time comes, the lecturer calls the level test applicant. This call will check the level test applicants and start lessons at the appropriate level. The call made by the instructor to the applicant for the level test is a so-called Internet phone, and the test can be taken while displaying a telephone as described later on the screen of the personal computer for which the level test is applied. If the level test cannot be performed at the designated time, the level test may be performed at another time later.

  After completing the level test as described above, the class to be taken is reserved by selecting the class that the language learner will take on the terminal screen, and the teaching materials in the electronic file format of the reserved class are reserved at the reserved time. It can be distributed on the terminal screen. FIG. 6 is a monitor screen when the language learner performs necessary login and exchanges information between the terminal and the network server 10 and then selects a class for the language learner to take. The window 61 displays language learner user information. The language learner's user information includes items such as name, registration deadline date, remaining days, number of classes, and level. These pieces of information stored in the network server 10 are transmitted and received by the above-mentioned original protocol, and the language is learned. Displayed on the learner's terminal monitor.

  On the right side of the banner of this system, a window 62 about the current time and the current situation is opened on the screen at the upper end and a position on the right side. Reservation is possible. In addition, a notification display section 63 for communication items and guidance items is provided at the bottom of the banner portion, and a face photo 64 of the instructor is displayed in a list together with the name at the bottom, which is one of judgment information for selecting a class. It has become one.

  At the bottom of the window 61 in which the language learner's user information is displayed, each class classified by level in a tree structure is displayed as a class list 65, and the language learner is displayed in the class list 65. By selecting a class that has been selected, the class to be taken is reserved. FIG. 7 is a screen immediately after selecting a class (beginner level, intermediate level, advanced level, special level) displayed in the class list table 65. The format of the table 66 for classes that can be further selected in the selected class. Is displayed. In the situation shown in FIG. 7, a class to be actually attended can be selected by clicking a participation button on the right end of the screen, and this creates a state of class reservation.

  When the class reservation is made, the screen moves to the class preparation screen. FIG. 8 shows a lesson preparation screen. Next to the clock display unit 68, a display unit 67 indicating a reservation status is provided, and a reservation status (class level, class start time) corresponding to data from the network server 10 is displayed. In the display section 69 below, the reservation status is displayed together with the teacher's face photo 70, and the display of “currently completed reservation” indicates that the language learner has made a reservation. The name of the instructor is also displayed in this part. This screen is further provided with two teaching material-related buttons 71 and 72, and the teaching material in the electronic file format of the reserved class is distributed on the terminal screen so that the language learner can receive it. Yes. Specifically, the button 71 is a button for teaching materials, and when clicked, an image file and an audio file are downloaded, and the language learner can see the teaching materials used in the lesson. The button 72 is a button for downloading an additional teaching material, and when the language learner clicks, the additional teaching material created by the instructor can be downloaded.

  In the lesson preparation screen shown in FIG. 8, the reserved lesson can be canceled by clicking the reservation cancel button 73. By clicking the cancel reservation button 73, the class reservation is not canceled immediately, but once a confirmation screen (not shown) with the content "Cancel?" Is displayed, and by selecting OK, Class reservation is canceled.

  The list return button 74 arranged alongside the reservation cancel button 73 is a button for returning to the class selection list, and when a language learner clicks in a state where a reservation is made, the list return button 74 is shown in FIG. Such a confirmation screen is displayed, and a notification that the reservation is in place and a message prompting participation in the class by 5 minutes before are displayed.

  Language learners take classes based on such reservations. At the reserved time, the personal computer 11 that is the instructor's terminal and the personal computer 22 that is the language learner's terminal that takes the course are connected via the network server 10, and the SIP as described above is connected. A video signal and an audio signal can be transmitted and received bidirectionally between terminals using a protocol that is non-compliant and has an audio automatic restoration function. In particular, since the voice data can be restored even if it is lost, the quality of the voice data can be maintained, and the deterioration of the voice quality can be minimized. In addition, it is non-compliant with SIP, which is a standard for Internet telephones, and lacks compatibility. However, the overhead can be reduced to a small size, and if the bit rate is limited or more students can be connected at the same time. This is particularly advantageous when desired.

  After the class is completed, the remote language learning system of the present embodiment can listen again by downloading and reproducing the electronic file of the class once received. FIG. 10 shows a recording list called “My class” that stores past data. By selecting and clicking a file to be reproduced from the recording list, the electronic file is downloaded. That is, when a file to be played is selected and clicked, a confirmation screen 75 for downloading the file is displayed. By clicking the “Open” or “Save” button on the confirmation screen 75 for downloading this file, You can get electronic files of the classes you have taken.

  Furthermore, in the remote language learning system of the present embodiment, it is possible to improve the learning efficiency of sentence creation ability such as diary and composition by sending and receiving data in an e-mail format. FIG. 11 shows a diary / composition transmission / reception screen. A list of corrected sentences is displayed in the item 77 at the center of the diary and composition transmission / reception screen. The language learner clicks a button 76 labeled “Write diary & composition” on the screen of FIG. 11 to advance to a screen on which a text writing box 78 as shown in FIG. 12 is displayed. A person can write a diary or write a composition. After completing the composition, the language learner clicks the send button 79 arranged at the bottom of the screen, so that the diary or composition created by the language learner is transmitted from the language learner's terminal to the network server 10 and transmitted. The completed diary or composition is sent to the teacher in the form of an e-mail. The instructor who receives the diary or composition from the network server 10 performs correction within a limited time, and the corrected sentence is transmitted to the language learner who has created the e-mail format. The corrected sentences sent to the language learner are displayed in the list of corrected sentences shown in FIG. 11. By selecting and clicking, the corrected sentences sent to the language learner are displayed. You can open and view the text.

  In the remote language learning system of this embodiment, a one-to-one class can be set between the language learner and the lecturer, but a class in an electronic conference format with a larger number of people is also possible. FIG. 13 shows a setting screen displayed when taking a course. A numeric keypad 81 is arranged in the center of the screen 80, and a send button 82, a delete button 83, and an end button 84 are arranged. In the column, a group button 85 for electronic conference is provided.

  First, when making a normal call, the ten key 81 is pressed to call a predetermined telephone number or the call button 82 is pressed to establish a connection with the instructor. When the group button 85 for electronic conference is pressed here, other learners can take classes while looking at their faces. That is, for example, during the course, there is a lecturer screen 87 as shown in FIG. 14, and when another student has attended the same class, another student's screen 87 is displayed at the bottom of the lecturer screen 87 as an incoming call. A screen 88 appears. When the group button 85 is clicked here, as shown in FIG. 15, a group-format screen is displayed as a pop-up screen 86, and other language learners who are attending at the same time are also displayed. The pop-up screen 86 is provided with an ID display section 90 or a status display section 89 of other students. In the example shown in FIG. 15, other learners displayed on the screen 88 are accepted. It is shown that it is in the state (accepted).

  As described above, in the remote language learning system of the present embodiment, classes can be advanced in the electronic conference format to other language learners, and more various language learning is possible.

  In the above-described embodiment, an example in which the communication system of the present invention is used as a remote language learning system has been described. However, the communication system of the present invention is not limited to this, and communication services to other remote locations, for example, It can also be applied to conference systems within the group, consulting to remote locations, medical services, etc. In the above-described embodiment, the terminal used by the user has been mainly described as a personal computer. However, a small electronic terminal device such as a mobile phone can also be used.

1 is a system configuration diagram illustrating a configuration example of a communication system according to an embodiment of the present invention. It is a schematic diagram of the protocol used for the communication system concerning embodiment of this invention. It is a figure which shows the registration screen in the terminal of the remote language learning acquisition system concerning embodiment of this invention. It is a figure which shows the personal information input screen in the terminal of the remote language learning acquisition system concerning embodiment of this invention. It is a figure which shows the application completion screen of the level test in the terminal of the remote language learning acquisition system concerning embodiment of this invention. It is a figure which shows the class reservation screen in the terminal of the remote language learning acquisition system concerning embodiment of this invention. It is a figure which shows the selection screen of the lesson in the terminal of the remote language learning acquisition system concerning embodiment of this invention. It is a figure which shows the preparation screen of the lesson in the terminal of the remote language learning acquisition system concerning embodiment of this invention. It is a figure which shows the alert display of the reservation state in the terminal of the remote language learning acquisition system concerning embodiment of this invention. It is a figure which shows the screen which shows the place which downloads the electronic file of the lesson in the terminal of the remote language learning acquisition system concerning embodiment of this invention. It is a figure which shows the selection screen of the diary and composition in the terminal of the remote language learning acquisition system concerning embodiment of this invention. It is a figure which shows the text input screen in the terminal of the remote word learning acquisition system concerning embodiment of this invention. It is a figure which shows the telephone display for a lecture in the terminal of the remote language learning acquisition system concerning embodiment of this invention. It is a figure which shows the introduction screen of the group format in the terminal of the remote language learning acquisition system concerning embodiment of this invention. It is a figure which shows the display screen of the group format in the terminal of the remote language learning acquisition system concerning embodiment of this invention.

Explanation of symbols

10 network server 11 personal computer 21 mobile phone 22 personal computer 23 USB terminal 24 earset 25 robot 26 electronic device 27 connection device 28 earset 29 router 30 internet 31 base station 41 registration start button 42 information box 43 basic information management button 44 telephone Number setting button 45 Credit charge button 46 Online phone book button 47 Logout button 49 Name input box 50 Nickname input box 51 Date of birth input box 52, 53 Radio button 61 Window 62 Window 63 Information display section 64 Face photo 65 Class list 66 Table 67 Display unit 68 Clock display unit 69 Display unit 70 Face photograph 71, 72 Button 73 Reservation cancel button 74 Restrictor Button 75 confirmation screen 76 button 77 item 78 writing box 79 send button 80 screen 81 numeric keypad 82 send button 83 delete button 84 end button 85 group button 86 pop-up screen 87, 88 screen 89 status display section 90 ID display section

Claims (7)

In a communication system that bidirectionally transmits and receives video signals and audio signals between terminals via a server and a communication line,
Using a protocol that is not compliant with SIP (Session Initiation Protocol) and has an automatic audio restoration function, the server connects the communication source terminal and the communication destination terminal in a bidirectional manner. A communication system characterized by transmitting and receiving. 2. The communication system according to claim 1, wherein the audio signal is transmitted in a packet format, and the data is restored for each packet when the packet is lost during the transmission by the automatic audio restoration function. Using a protocol that is compliant or non-compliant with SIP (Session Initiation Protocol) and has an automatic audio restoration function, the server connects the communication source terminal and the communication destination terminal via a communication line to connect the video signal and the audio signal. A remote language learning acquisition system characterized in that a language learner operates one terminal while a language learner operates the other terminal, and a language instructor operates the other terminal. By selecting the class to be taken by the language learner on the terminal screen, the class to be attended is reserved, and the teaching materials in the electronic file format of the reserved class can be distributed on the terminal screen at the reserved time 4. The distance learning system according to claim 3, wherein: The server records a lesson that the language learner takes, and in response to a request from the language learner, the lesson recorded via the communication system is stored in the terminal operated by the language learner. 4. The distance learning system according to claim 3, wherein redistribution is performed again. The remote server according to claim 3, wherein the server accepts an application for a level test from a new registrant of the language learner and sets a level test to be performed by a language instructor for the other terminal. system. 4. The server according to claim 3, wherein the server holds a lesson taken by the plurality of language learners in an electronic conference format, and the language learner participating in the terminal is displayed with a nickname instead of a real name. Remote language learning system.