CN1472713A - Satellite multimedium bidirectional long-range real-time teaching systems - Google Patents
Satellite multimedium bidirectional long-range real-time teaching systems Download PDFInfo
- Publication number
- CN1472713A CN1472713A CNA03116983XA CN03116983A CN1472713A CN 1472713 A CN1472713 A CN 1472713A CN A03116983X A CNA03116983X A CN A03116983XA CN 03116983 A CN03116983 A CN 03116983A CN 1472713 A CN1472713 A CN 1472713A
- Authority
- CN
- China
- Prior art keywords
- client
- transponder
- classroom
- satellite
- service centre
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Landscapes
- Management, Administration, Business Operations System, And Electronic Commerce (AREA)
Abstract
The system utilizes multimedia client end, retransmitter, retransmission service centre, class management and service centre to carry on three functions of video-audio class, data class and class management. The multimedia client end scattered at each small satellite station is connected to internal connected retransmitter through Ethernet and the retransmitter is connected to external connected server which connects to retransmission centre of server at main satellite station through two-way satellite network connection. The class service centre is at server of the main satellite station and the multimedia client end is connected to retransmission center at main satellite station server and class management and service centre.
Description
Technical field
What the present invention relates to is the real-time tutoring system of a kind of multimedia remote, and the real-time tutoring system of particularly a kind of two-way satellite multimedia remote belongs to field of computer technology.
Background technology
Develop rapidly along with the multimedia and the network communications technology, Web education/long-distance education from originally deriving to the pattern based on two-way satellite network based on the pattern of LAN (Local Area Network) and Internet, has also obtained significant achievement in research aspect the multimedia real time remote education of two-way satellite network and application.Through new to looking into of prior art, they are respectively to retrieve two kinds of like products: the TrainNet of Israel Mentergy company exploitation; The Meeting point 4.5 of Israel VCON company exploitation.
The TrainNet of Israel Mentergy company exploitation is present the most powerful in the world interactive remote tutoring system, has become the TBT industrial standard that directly arrives PC.The student is by an integrated environment participation in learning.High-quality, full screen video effect, real-time, interactive and cooperation, application are shared etc. for the student and are created a real efficient academic environment.Two kinds of lesson patterns of this product support synchronous versus asynchronous are only supported the connected mode of multicast, and supported minimum upstream bandwidth is 128kbps (video)+8kbps (audio frequency), only supports unidirectional a screen broadcasting.The Meeting point 4.5 of Israel VCON company exploitation is the most general interactive remote tutoring system of domestic use.Application target at the beginning of its design is at multipoint videoconference, because it is mutual to looking audio frequency, and blank, application program is shared and is waited the interactive operation support better, thereby is able to widespread use in long-distance education.This product support is (clean culture) and two kinds of interactive modes of one-to-many (multicast) one to one, look audio compression/decompression and multicast control by hardware, can't directly arrive student's desktop.Supported minimum upstream bandwidth is 138kbps.
There is the problem of following several respects in existing system: (1) can't support to look on the narrow upstream bandwidth (such as being lower than 100kbps) the normal mutual of audio frequency; (2) can't support the across a network transmission of multicast packet, and then cause system teaching resource directly can't be delivered to student's desktop; (3) across a network that can't back-up system is disposed, and then the student's terminal number amount limited (often the number with the satellite small station is identical) that causes system to support; (4) the synchronous system of giving lessons in real time of great majority has directly adopted the multiple spot group interaction mechanism in the video conferencing system, and this interaction mechanism is not suitable for giving lessons in real time.Adopt this interaction mechanism, not only increased the complexity of tension management, also cause the expense of unnecessary system resource overhead, particularly network bandwidth resources simultaneously.
Summary of the invention
The objective of the invention is to overcome deficiency of the prior art, the real-time tutoring system of a kind of two-way satellite multimedia remote (being referred to as astroTrainer) is provided, the advantage that makes it not only can utilize the two-way satellite high-speed access technology not to be subjected to the region restriction and can to bundle satellite TV, and can overcome the defective of satellite uplink bandwidth narrow (the minimum 76.8kbps of reaching), the real-time, interactive of multi-medium datas such as audio frequency, screen and blank is looked two-way in realization, this external enwergy is supported client as much as possible, and the client cost is low, the building mode simple and flexible.
The present invention is achieved by the following technical solutions, the present invention is made up of multimedia client, transponder, four relatively independent application components of forwarding service centre and class management service centre, multimedia client (Client) is the end user terminal of system; Transponder (Transmit Part), it is the multi-medium data transfer service node between satellite network and ground LAN, be divided into inline transponder and outreach transponder two classes, be responsible for the transmission of multi-medium data between each multimedia client of system by network; Transmit service centre (Transmit Server), be positioned at the transponder of satellite main website server; Class management service centre (Class Management Service) is made of one group of Web Service, is the control center of total system; Four common formation of part look the audio frequency classroom, data classroom and class management three big functions, the multimedia client distribution is in each location, satellite small station, all multimedia clients that are positioned at a place are connected to inline transponder by the ground Ethernet, inline transponder links to each other with the server that outreaches on being arranged on local satellite small station machine by the ground special line, the all forwarding service centres that outreach server and be positioned at satellite main website server that are positioned at each satellite small station connect by two-way satellite network, the service centre of class management simultaneously also is positioned on the satellite main website server, any one multimedia client can be connected to forwarding service centre and the class management service centre on the satellite main website server, thereby four parts have formed an integral body closely, present star-like by different level topological structure.
Total system is structured on ICP/IP protocol and the .NET Framework, adopt the http connection protocol between multimedia client and the class management central server, multimedia client and inline transponder, inline transponder and outreach between the transponder, outreach transponder and adopt udp protocol to be connected between the service centre with transmitting, total system presents the general structure of loose coupling.
The multimedia client all is to link to each other with satellite network by ground LAN among the present invention, between ground LAN and satellite network, there is fire wall, and class management service centre is positioned at the satellite main website, therefore client will be finished the alternately necessary firewall-penetrating of control information with class management service centre, adopting http to call Web Service is the good method that addresses this problem, this in addition method is placed on server end with main processing capacity and carries out, alleviated the burden of client, thereby made system can support client as much as possible.So the multimedia client makes up based on the Web mode among the present invention, need not to locate to install client the final user, the user can be easy and convenient passes through browser participation system, the operation of being correlated with.The multimedia client comprises three parts: the control of authority module, look audio frequency classroom module and data classroom module.(1) control of authority module and class management service centre carry out the mutual of state, control information, according to interaction results the mutual authority of multi-medium data of looking audio frequency classroom module and data classroom module of client is controlled and managed, control of authority module in addition also is responsible for being updated in the user list that client shows.(2) look audio frequency classroom module, be responsible for to receive, the decoding video/audio and at local playback or coding, send the video/audio that from local video and audio equipment, collects.The audio frequency classroom module of looking of all clients link to each other to constitute a complete audio frequency classroom of looking by transponder in the classroom.The audio frequency of looking that whenever receives two sides that is in that arbitrary client in the classroom carries out in the classroom to multipotency.Wherein Fang Shi teacher end look audio frequency, run through the classroom all the time, and this video/audio source remains in carry out in the classroom constant; An other Fang Shiyu teacher looks the audio frequency of looking of the mutual focus student's end of audio frequency, according to the mutual needs of teacher and student in the classroom or occur or disappear, the source of focus student's video/audio is then determined according to the mutual authority instruction of control of authority module, can be made a change according to the field research needs in carry out in the classroom.(3) data classroom module, this functional module comprises two parts: share screen and Sharing Whiteboard.Be positioned at the local teacher computer screen picture of data classroom module charge capture and the blank data of teacher's end, and compress, send to the data classroom module of causing trouble in the middle school, classroom by transponder, it also receives focus student end and carries out mutual multi-medium data and it is reduced superposition on local screen and blank on shared screen and Sharing Whiteboard in addition.Be positioned at the screen picture of the teacher computer that the data classroom module decompress(ion) of student end receives and blank data and repaint the multimedia interactive data of focus student's end that superposition receives on this external image that repaints in this locality.The data classroom module of all clients is by complete data classroom of the continuous formation of transponder in the classroom.The data classroom has strengthened the interactive means between the teachers and students, and the teachers and students that embodied field research are interactive.Can share the screen of teacher's client by sharing the screen module student client, authorized focus student's end can also be operated the screen of teacher's end, this is that large-scale electronic document teaching (as Word, PPT) provides effective instrument with the software collaboration teaching; By collaborative fully Sharing Whiteboard instrument, the focus student of teacher and mandate can be by the collaborative call for Votes of blank.
The multimedia client can be divided into teacher's client by its user identity that lands, student client and Administrator Client, and they have different authorities separately, can carry out different operations.Teacher's client can be used real-time video, audio frequency, and by electronic whiteboard, instruments such as Screen sharing and text Chat carry out alternately with the student, and can ratify/forbid student's video, audio frequency and operate shared screen.Student client can use real-time video, audio frequency, and by electronic whiteboard, and operation shares that other students carry out alternately in instrument such as screen and text Chat and teacher and the classroom.The Administrator Client can manage identity and the authority thereof of all users in the system, and can manage and distribute the classroom resource.
In addition, the multi-medium data amount of being sent by teacher's client is bigger, to the outlet bandwidth size requirements than higher, carry out in the process in the classroom, teacher's client is all the time in operation, and student client is relatively more responsive to the time-delay of the multi-medium data of teacher's client, therefore teacher's client links to each other with the satellite main website by the ground special line in the system, made full use of satellite downlink bandwidth broad, the characteristics that data rate is fast, and student client links to each other with the satellite small station by the ground multicast network, holds multi-medium data transmitting speed and quality to guarantee the teacher, and makes system can support student client as much as possible.
In order to enlarge teaching scale as much as possible and to solve teaching point location and the inconsistent problem of satellite main website or geographic position, small station in the field research application, the present invention adopts two kinds of internetwork connection modes: clean culture and multicast.Therefore the multimedia client can be divided into clean culture client and multicast client two classes by the mode that it connects network.Student client links to each other with the transponder of local area network in the multicast mode.Teacher's client directly links to each other with forwarding service centre with mode of unicast by the ground special line.
Transponder is the multi-medium data transfer service node between satellite network and ground LAN, is divided into inline transponder and outreaches transponder two classes.The network environment difference that they are positioned at, inline transponder is positioned at the ground LAN server, and outreaches the server that transponder is positioned at corresponding satellite small station, connects by the ground special line between them.The multi-medium data that inline transponder is responsible for local client is sent is at the local area network multicast, and its clean culture sent to outreaches transponder accordingly; Perhaps clean culture receives and to outreach multi-medium data that transponder sends at the local area network multicast.Because each satellite small station and satellite main website constitute one to the transparent IP multicast network of satellite user by the mapping of IP agreement, therefore all are positioned at the LAN (Local Area Network) topological structure that transponder forms a support IP multicast that outreaches of satellite small station and main website, outreach transponder be responsible for multi-medium data that clean culture is received via satellite network multicast send to other and outreach server, the multi-medium data that multicast is received sends to corresponding inline server by ground special line clean culture.
Transmitting service centre, is a special transponder that outreaches, and it is positioned on the satellite main website server, has bigger outlet bandwidth in satellite network, makes it become the collecting and distributing centre of multi-medium data maximum in the system.Look multi-medium datas such as audio frequency, screen and blank because teacher's client sends in the system, data volume is bigger, therefore must be by the descending transponder that outreaches that multicasts on each little site server of the forwarding service centre that is positioned at the main website server.Compare with other server that outreaches that is positioned at the small station in addition, in order to reduce the consumption of system, accelerate the propagation of teacher's client data, transmit the connection that service centre supports the clean culture client, allow teacher's client to be connected to and transmit service centre by the direct clean culture of ground special line.Transmit service centre and also can the multicast reception outreach the multi-medium data that server forwards is come, and its clean culture is sent to relevant teacher's client, finish real-time, interactive from each small station.
Transponder and forwarding service centre adopt two kinds of data forwarding modes: (1) clean culture
Multicast; (2) multicast
Multicast forwarding.The satellite multicast network is made of the server that outreaches of transmitting service centre and each small station; The ground multicast network is made of jointly the inline transponder of student's end with this locality.Each transponder and transmit service centre by with the classroom of a plurality of activities of mutual dynamic creation of class management service centre, there is a multicast address in each classroom, ports are transmitted in six multicast port and three clean cultures.The present invention allows a large amount of simultaneous users to add virtual classroom by the IP multicasting technology, and has broken through the restriction to teaching point geographic position of satellite main website or small station by the clean culture forwarding capability.
Class management service centre is made of one group of .NET Web Service, the backstage has database server to support, it is the control center of total system, the multimedia client, transmit service centre, inline transponder outreaches transponder and carries out alternately with class management service centre by the http request, class management service centre obtains total system the most comprehensive current most complete information by http response, thereby provides the comprehensive coordination ability for the different ingredients of system.Class management service centre provides management function for limited classroom resource, both can newly-built classroom, also can follow the tracks of set classroom, and also can carry out rights management to users all in the system easily.Class management service centre supports the user of Faculty and Students by clicking the function in the links and accesses classroom in the page in addition.
Two-way satellite is meant and The present invention be directed to that existing bidirectional high speed inserting of satellite technology designs, it is advantageous that: at first, the two-way satellite this mode simple, intuitive of giving lessons in real time, contain much information, the technology " door " of study is not high, be convenient to the student and accept, the means of education meet student's characteristics of cognition.Secondly, though the remote teaching of internet type has the advantage of self, wherein will relate to such as numerous equipment such as router, switch, servers, increase numerous factors of instability to system undoubtedly, satellite network then stablizes manyly in this respect.The 3rd, broad covered area can be on the outskirts of a town, telecommunications such as rural area and remote districts and cable network field beyond one's ability to help realizes real-time distant learning, really broken through the geographic restrictions of teaching.The 4th, the problem that administers and maintains exactly, the two-way satellite network teaching all more is suitable for operation than internet teaching on administering and maintaining, and cost is also low.Consider existing two-way broadband inserting of satellite technology higher uplink bit rate not ideal enough (80kbps-300kbps), be difficult to adapt to the characteristics that a large amount of higher uplink bit rate in real time required such as two-way multimedia interactive services such as remote teaching, the present invention is by asymmetric video compressing and encoding method, promptly the teacher's video data by the broader bandwidth downlink transmission is adopted high sample frequency, high resolving power, the method of low compression ratio is compressed, to guarantee teacher's video quality; The focus student's video data that transmits by the up-link of narrow bandwidth is then adopted low sample frequency, low resolution, the method for high compression ratio is compressed, to reduce up the video data volume; Using of Hook technology reduced the flow (only being 70-75kbps) that Sharing Whiteboard in real time up in the two-way multimedia interactive service reaches shared on-screen data in a large number in addition, realized at the real-time, interactive of crossing on the narrow bandwidth (minimum 76.8kbps).Therefore, the present invention is a tutoring system based on two-way satellite network, support two-way multimedia real-time, interactive.
The present invention also has the following advantages:
● support many classrooms instruction through satellite pattern
The present invention allows to carry out simultaneously a plurality of classrooms, and each classroom can both independently be opened on time and finish automatically.The keeper can set a restriction for the classroom quantity of carrying out simultaneously in the system, and this restriction permission takies the network bandwidth based on the classroom COS to be adjusted.
● the classroom persistence
That can visit when being in connection status with the promoter is different to the equation meeting, no matter whether has the classroom participant, and the virtual classroom among the astroTrainer all will continue to carry out in whole predetermined period.This mode provides more flexible and real classroom model, and the classroom participant can add at any time or leave the classroom, and need not to worry whether the classroom can be interrupted.
● support automatically restoring fault
The invention provides the automatic recovery mechanism of a cover, when having abnormal conditions to occur in the system, need not manual intervention, system can carry out a series of processing automatically.For example for the withdrawing from unusually of client, system can revise the state of relative client automatically.By the machine-processed normal operation that has guaranteed system of this cover, improved the robustness and the reliability of system.
The present invention has substantive distinguishing features and marked improvement, the present invention utilizes the two-way satellite high-speed access technology that audio frequency is looked at the scene of imparting knowledge to students, share the collection and the Network Transmission of screen and Sharing Whiteboard data, realize that the on-the-spot multimedia of teaching is live, and overcome the narrow defective of two-way satellite upstream bandwidth, broken through the restriction of region and environmental baseline in the teaching, realized that teachers and students look audio frequency, functions such as the real-time, interactive of Sharing Whiteboard and shared screen and class management monitoring, solved the restriction problem of traditional classroom instruction on time and space, expanded teaching scale greatly, realize that the master gives lessons, sharing and teachers and students' cooperation interaction of educational resource, and reduced the cost of extensive teaching.
Description of drawings
Fig. 1 overall construction drawing of the present invention;
Fig. 2 the present invention based on the two-way satellite network topology diagram;
Fig. 3 functional module calling graph of the present invention;
Fig. 4 multimedia client of the present invention working mechanism synoptic diagram;
Fig. 5 transponder of the present invention and module working mechanism of forwarding service centre synoptic diagram.
Embodiment
Provide following examples in conjunction with content of the present invention, the present invention is done further understanding, specific as follows:
Fig. 1 has provided general frame of the present invention, below will describe the enforcement operating mechanism of total system according to this width of cloth figure.Teacher's end links to each other with the satellite main website by the ground special line in the system, and student's end links to each other with the satellite small station by the ground multicast network.In actual operation, the student end that is positioned at ground LAN in each location, satellite small station is constituted a ground multicast network with inline transponder, inline transponder links to each other with the transponder that outreaches on being positioned at local satellite small station by the ground special line.The multi-medium data that inline transponder can be held transmission with local student is at the local area network multicast, and its clean culture sent to outreaches transponder accordingly; Perhaps clean culture receives and to outreach multi-medium data that transponder sends at the local area network multicast.All the forwarding service centre that outreaches transponder and be positioned at main website IP agreement mappings via satellite that are positioned at the satellite small station form one to the transparent satellite multicast network of satellite user, outreach transponder be responsible for the multi-medium data that will receive from corresponding inline transponder clean culture via satellite network multicast send to other and outreach transponder and transmit service centre, and will send to corresponding inline transponder by ground special line clean culture from the multi-medium data that the satellite network multicast receives.Teacher's end directly carries out clean culture with the forwarding service centre of main website by the ground special line and is connected.The teacher holds a large amount of multi-medium data clean cultures is sent to forwarding service centre, the multi-medium data multicast that forwarding service centre receives clean culture sends to each small station and outreaches server, and multicast receives and to outreach the multi-medium data that server forwards is come from each small station, and its clean culture is sent to relevant teacher's client.By above connection and data forwarding, realized a plurality of classroom teachers and the real-time multimedia interactive of focus student simultaneously, comprise and look audio frequency that Sharing Whiteboard and shared screen are mutual.In the implementation process, having adopted downlink bandwidth is 2Mbps, and upstream bandwidth is the two-way satellite network of 76.8kbps, and it is 400-500kbps that each teacher holds multi-medium data to send shared bandwidth, therefore can support 4 classrooms to carry out simultaneously at most; It is 50-70kbps that focus student holds multi-medium data to send shared bandwidth, so each satellite small station any time can only add a classroom.The Administrator Client can directly link to each other with satellite main website server by the ground special line in addition, also can be connected the student and hold in the ground LAN at place, they are realized the classroom resource of system and user's management by the class management service (one group of Web Service) that http calls the class management service centre that is arranged in the satellite main website and provides.
Shown in Figure 2, be a real-time tutoring system of experimental two-way satellite multimedia remote based on the two-way satellite network topological structure, it is Centroid with the main website, constitutes starlike communication network with each far-end VSAT small station.Main website both can broadcast the public information business to the whole network, also can be respectively with each VSAT small station with " one jumps " (Single-hop) mode set up separately two way traffic contact.And main website can be used as Hub with " double bounce " (Double-hop) mode link up communication line between any two VSAT small stations.This network structure is applicable to that the whole network has only an information center, and each far-end small station mainly is to communicate by letter with information center and user that portfolio is little.This system can support business such as speech, fax, image.But telephone traffic can not be excessive, otherwise network efficiency reduces.The descending 2Mbps that is marked among the figure, the amount of bandwidth of the two-way link of the two-way satellite network that the bandwidth of passback 76.8kbps is adopted when being experiment.In practical operation, whole satellite network can be constituted the multicast network to user transparent by IP agreement mapping, satellite main website and each far-end satellite small station are the different nodes on this multicast network.Because star-like topological structure and the asymmetric communication channel of satellite network, different with the multicast network that ground LAN forms, each node on the satellite multicast network is also asymmetric, multicast bandwidth reached 2Mbps when master node was initiated point as multicast, and each small station node when initiating point as multicast multicast bandwidth have only 76.8kbps.In addition, the time delay of data transmission is 750ms (" one jumps ") in experiment between main website and the small station, and the time delay of data transmission reaches 750*2=1500ms (" two jump ") between small station and the small station in experiment.
Shown in Figure 3, the present invention includes the multimedia client, transponder is transmitted service centre and four relatively independent application components of class management service centre.Logical functional structure by system is divided, the present invention includes application layer (Application), backstage service (BackClass Service), Control Server (ControlServer) and four functional modules of data transmitting server (Data Transmition Server), be called for short A, B, C, D module.Application layer module mainly comprises the multimedia client, and background server module and Control Server module constitute class management service centre, and the data transmitting server module comprises transponder and transmits service centre.Provided the call relation between these four functional modules among the figure, application layer module comprises the multimedia client, and it presents to the user in the Web mode, is embedded with in the client terminal web page interface and looks Audio Controls, shares screen and Sharing Whiteboard control.Exist the data based on udp protocol to be connected between these controls and the data transmitting server module, connected mode is that multicast mixes mutually with clean culture, and the operating mechanism between they and the data forwarding service module has provided detailed description in Fig. 5.The Control Server module is responsible for the access rights control to the classroom resource of all users in the system, regularly upgrades user list, and the user who logs off is unusually managed.Control Server calls the class management service that provides in the service module of backstage by http and realizes control function.Backstage service module unified management database server, Web server, and provide one group of Web Service to carry out http to client and Control Server to call is for the different ingredients of system provide the comprehensive coordination ability.The multimedia client all is to link to each other with satellite network by ground LAN among the present invention, have fire wall between ground LAN and satellite network, method firewall-penetrating and class management service centre that customer end adopted http calls Web Service finish the mutual of control information.The present invention adopts the integration mode of loose coupling, the Componentized development scheme.Related less between each module, independence is bigger, can not have influence on other module to the expansion of certain functions of modules.In addition, class management service centre adopts Web Service mode to develop, not only call conveniently, and can the expansion management function by increasing newly or revising Web Service.
As shown in Figure 4, the multimedia client is the most complicated ingredient of structure among the present invention, has described its working mechanism among the figure.The multimedia client comprises three parts based on the Web mode: the control of authority module, look audio frequency classroom module and data classroom module.(1) control of authority module and class management service centre carry out the mutual of state, control information, according to interaction results the mutual authority of multi-medium data of looking audio frequency classroom module and data classroom module of client is controlled and managed, control of authority module in addition also is responsible for being updated in the user list that client shows.(2) look audio frequency classroom module, be responsible for to receive, the decoding video/audio and at local playback or coding, send the video/audio that from local video and audio equipment, collects.(3) data classroom module, this functional module comprises two parts: share screen and Sharing Whiteboard.Be positioned at the local teacher computer screen picture of data classroom module charge capture and the blank data of teacher's end, and compress, send to the data classroom module of causing trouble in the middle school, classroom by transponder, it also receives focus student end and carries out mutual multi-medium data and it is reduced superposition on local screen and blank on shared screen and Sharing Whiteboard in addition.Be positioned at the screen picture of the teacher computer that the data classroom module decompress(ion) of student end receives and blank data and repaint the multimedia interactive data of focus student's end that superposition receives on this external image that repaints in this locality.
Transponder and forwarding service centre are the hinges of multi-medium data distribution transmission among the present invention, the present invention is in order to support student client as much as possible, adopted the IP multicasting technology, two multicast networks have been constructed, be respectively to outreach server by the interconnected satellite multicast network that constitutes of two-way satellite network by what transmit service centre and each small station, and by student's end of locality and inline transponder by the interconnected ground multicast network that constitutes of ground Ethernet.The transmission mode that this external system mixes with clean culture by multicast has realized the seamless link of satellite multicast network and ground LAN multicast network.Transponder and forwarding service centre adopt two kinds of pass-through modes: (1) clean culture
Multicast; (2) multicast
Multicast forwarding; The working mechanism of these two kinds of pass-through modes as shown in Figure 5.Each transponder and transmit service centre by with the classroom of a plurality of activities of mutual dynamic creation of class management service centre, there is a multicast address in each classroom, ports are transmitted in six multicast port and three clean cultures.
Implementation result: the present invention has broken through the restriction of region and environmental baseline in the teaching, has realized the cost of sharing and greatly reduce extensive teaching of outstanding educational resource; Adopt the two-way satellite high-speed access technology to carry out real-time multimedia remote education, compared with similar products, not only can support to look normally on the narrower upstream bandwidth (the minimum 76.8kbps of reaching) the two-way real-time, interactive of multi-medium datas such as audio frequency, screen and blank, and can support client as much as possible, and the client cost is low, and is simple to operate flexible.
Claims (8)
1, the real-time tutoring system of a kind of two-way satellite multimedia remote, comprise: the multimedia client, transponder, transmit service centre and class management service centre, it is characterized in that, the multimedia client, it is the end user terminal of system, transponder is the multi-medium data transfer service node between satellite network and ground LAN, be responsible for the transmission of multi-medium data between each multimedia client of system by network, be divided into inline transponder and outreach transponder two classes, transmit the transponder that service centre is positioned at satellite main website server, class management service centre is made of one group of Web Service, it is the control center of total system, four common formation of part look the audio frequency classroom, data classroom and class management three big functions, the multimedia client distribution is in each location, satellite small station, all multimedia clients that are positioned at a place are connected to inline transponder by the ground Ethernet, inline transponder links to each other with the server that outreaches on being arranged on local satellite small station machine by the ground special line, the all forwarding service centres that outreach server and be positioned at satellite main website server that are positioned at each satellite small station connect by two-way satellite network, the service centre of class management simultaneously also is positioned on the satellite main website server, any one multimedia client can be connected to forwarding service centre and the class management service centre on the satellite main website server, thereby four parts have formed an integral body closely, present star-like by different level topological structure.
2, the real-time tutoring system of two-way satellite multimedia remote according to claim 1, it is characterized in that, total system is structured on ICP/IP protocol and the NET Framework, adopt the http connection protocol between multimedia client and the class management central server, carry out the mutual of control information, multimedia client and inline transponder, inline transponder and outreach between the transponder, outreaching transponder adopts udp protocol to be connected with transmitting between the service centre, carry out the mutual of multi-medium data, total system presents centralized control, the general structure of loose coupling.
3, the real-time tutoring system of two-way satellite multimedia remote according to claim 1, it is characterized in that, the multimedia client is based on the Web mode, need not to locate to install client the final user, the user is by the browser participation system, the operation of being correlated with, the user of Faculty and Students is by clicking the links and accesses classroom in the page, the keeper is by web administration user and classroom resource, therefore, can be divided into teacher's client by the user identity multimedia client of landing, three kinds of student client and Administrator Clients, the multimedia client comprises three parts: the control of authority module, look audio frequency classroom module and data classroom module:
(1) control of authority module and class management service centre carry out the mutual of state, control information, according to interaction results the mutual authority of multi-medium data of looking audio frequency classroom module and data classroom module of client is controlled and managed, control of authority module in addition also is responsible for being updated in the user list that client shows;
(2) look audio frequency classroom module, be responsible for reception, decoding video/audio and at local playback or coding, the video/audio that transmission collects from local video and audio equipment, the audio frequency classroom module of looking of all clients link to each other to constitute a complete audio frequency classroom of looking by transponder in the classroom, be in the audio frequency of looking that whenever receives two sides at the most that the arbitrary client in the classroom is carried out in the classroom, wherein Fang Shi teacher's client looks audio frequency, run through the classroom all the time, an other Fang Shiyu teacher looks the audio frequency of looking of the mutual focus student client of audio frequency, according to the mutual needs of teacher and student in the classroom or occur or disappear, the source of focus student's video/audio is then determined according to the mutual authority instruction of control of authority module, can be made a change according to the field research needs in carry out in the classroom;
(3) data classroom module, this functional module comprises two parts: share screen and Sharing Whiteboard, be positioned at the local teacher computer screen picture of data classroom module charge capture and the blank data of teacher's client, and compress, send to the data classroom module of causing trouble in the middle school, classroom by transponder, it also receives the focus student client and carries out mutual multi-medium data and it is reduced superposition on local screen and blank on shared screen and Sharing Whiteboard, be positioned at the screen picture of the teacher computer that the data classroom module decompress(ion) of student client receives and blank data and repaint in this locality, the multimedia interactive data of focus student's end that superposition receives on the image that repaints, the data classroom module of all clients is by complete data classroom of the continuous formation of transponder in the classroom, can share the screen of teacher's client by sharing the screen module student client, authorized focus student's end can also be operated the screen of teacher's end, by collaborative fully Sharing Whiteboard instrument, the focus student of teacher and mandate can be by the collaborative call for Votes of blank.
4, according to claim 1 or the real-time tutoring system of 3 described two-way satellite multimedia remotes, it is characterized in that, the multimedia client can be divided into clean culture client and multicast client two classes by the mode that it connects network, student client links to each other with the inline transponder of local area network in the multicast mode, and teacher's client directly links to each other with forwarding service centre with mode of unicast by the ground special line.
5, the real-time tutoring system of two-way satellite multimedia remote according to claim 1, it is characterized in that, transponder, be divided into inline transponder and outreach transponder two classes, inline transponder is positioned at the ground LAN server, and outreaches the server that transponder is positioned at corresponding satellite small station, connects by the ground special line between them, the multi-medium data that inline transponder is responsible for local client is sent is at the local area network multicast, and its clean culture sent to outreaches transponder accordingly; Perhaps clean culture receives and to outreach multi-medium data that transponder sends at the local area network multicast, each satellite small station and satellite main website constitute one to the transparent multicast network of satellite user, all transponders that outreach that are positioned at satellite small station and main website form a LAN (Local Area Network) topological structure of supporting the multicast mode, outreach transponder be responsible for multi-medium data that clean culture is received via satellite network multicast send to other and outreach server, the multi-medium data that multicast is received sends to corresponding inline server by ground special line clean culture.
6, the real-time tutoring system of two-way satellite multimedia remote according to claim 1, it is characterized in that, transmit service centre, it is a special transponder that outreaches, it is positioned on the satellite main website server, in satellite network, has bigger outlet bandwidth, it is the collecting and distributing centre of multi-medium data maximum in the system, teacher's client sends in the system looks audio frequency, multi-medium data such as screen and blank, data volume is bigger, must be by the descending transponder that outreaches that multicasts on each little site server of the forwarding service centre that is positioned at the main website server, transmit the connection of service centre's support clean culture client, allow teacher's client to be connected to and transmit service centre by the direct clean culture of ground special line, transmit service centre and also can the multicast reception outreach the multi-medium data that server forwards is come from each small station, and its clean culture sent to relevant teacher's client, finish real-time, interactive.
7, the real-time tutoring system of two-way satellite multimedia remote according to claim 1, it is characterized in that, adopt the IP multicasting technology, there are two kinds of multicast networks, be respectively to outreach server by the interconnected satellite multicast network that constitutes of two-way satellite network by what transmit service centre and each small station, by the student of locality end and inline transponder by the interconnected ground multicast network that constitutes of ground Ethernet, the transmission mode of mixing with clean culture by multicast has realized the seamless link of satellite multicast network and ground LAN multicast network, and transponder and forwarding service centre adopt two kinds of data forwarding modes in view of the above: (1) clean culture
Multicast; (2) multicast
Multicast forwarding, each transponder and transmit service centre by with the classroom of a plurality of activities of mutual dynamic creation of classroom service centre, there is a multicast address in each classroom, ports are transmitted in six multicast port and three clean cultures.
8, the real-time tutoring system of two-way satellite multimedia remote according to claim 1, it is characterized in that, class management service centre, constitute by one group of Web Service, the backstage has database server to support, it is the control center of total system, the multimedia client, transmit service centre, inline transponder outreaches transponder and carries out alternately with class management service centre by the http request, and class management service centre obtains total system the most comprehensive current the most intactly information by the http response, class management service centre provides management for limited classroom resource, both can newly-built classroom, also can follow the tracks of set classroom, also can carry out rights management to users all in the system, in addition, further expand the class management center function by newly-increased or modification Web Service.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNA03116983XA CN1472713A (en) | 2003-05-16 | 2003-05-16 | Satellite multimedium bidirectional long-range real-time teaching systems |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNA03116983XA CN1472713A (en) | 2003-05-16 | 2003-05-16 | Satellite multimedium bidirectional long-range real-time teaching systems |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN1472713A true CN1472713A (en) | 2004-02-04 |
Family
ID=34152643
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNA03116983XA Pending CN1472713A (en) | 2003-05-16 | 2003-05-16 | Satellite multimedium bidirectional long-range real-time teaching systems |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN1472713A (en) |
Cited By (15)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101872555A (en) * | 2010-05-31 | 2010-10-27 | 中山大学 | Real-time interactive teaching system based on application-layer multicast services |
| CN102546194A (en) * | 2010-12-24 | 2012-07-04 | 联想(北京)有限公司 | Display data processing method, system and server |
| CN103473963A (en) * | 2013-09-26 | 2013-12-25 | 苏州阔地网络科技有限公司 | Synchronous classroom processing method and system |
| CN103780348A (en) * | 2014-01-23 | 2014-05-07 | 北京邮电大学 | DCS satellite link downlink data acknowledgement frame transmission method |
| CN103795614A (en) * | 2014-03-10 | 2014-05-14 | 上海四方信息技术股份有限公司 | Instant mobile communication system and method |
| CN104065646A (en) * | 2014-06-04 | 2014-09-24 | 广州华多网络科技有限公司 | Online class fault processing method, device and system |
| CN104320405A (en) * | 2014-11-06 | 2015-01-28 | 中国电子科技集团公司第五十四研究所 | Internet surfing optimization method applicable to star satellite network |
| CN104471527A (en) * | 2012-07-20 | 2015-03-25 | 三星电子株式会社 | Method and device for sharing content |
| CN104580308A (en) * | 2013-10-21 | 2015-04-29 | 中兴通讯股份有限公司 | Virtual desktop reappearing and pushing method and device and virtual desktop system |
| CN104882037A (en) * | 2015-06-02 | 2015-09-02 | 阔地教育科技有限公司 | Live-recorded broadcast interaction classroom system |
| CN105376201A (en) * | 2014-08-26 | 2016-03-02 | 天脉聚源（北京）教育科技有限公司 | Multimedia information interactive system and interactive method |
| CN106330929A (en) * | 2016-08-30 | 2017-01-11 | 四川教云网络科技有限公司 | Interactive education system based on two-way communication satellite and working method thereof |
| CN106781758A (en) * | 2016-12-27 | 2017-05-31 | 深圳市汇龙建通实业有限公司 | A kind of Intelligent campus management system |
| CN108269438A (en) * | 2018-02-09 | 2018-07-10 | 河南理工大学 | A kind of network training education apparatus |
| CN108965786A (en) * | 2018-07-25 | 2018-12-07 | 深圳市异度信息产业有限公司 | A kind of electronic whiteboard content sharing method and device |
-
2003
- 2003-05-16 CN CNA03116983XA patent/CN1472713A/en active Pending
Cited By (23)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101872555B (en) * | 2010-05-31 | 2012-06-06 | 中山大学 | Real-time interactive teaching system based on application-layer multicast services |
| CN101872555A (en) * | 2010-05-31 | 2010-10-27 | 中山大学 | Real-time interactive teaching system based on application-layer multicast services |
| CN102546194A (en) * | 2010-12-24 | 2012-07-04 | 联想(北京)有限公司 | Display data processing method, system and server |
| CN104471527A (en) * | 2012-07-20 | 2015-03-25 | 三星电子株式会社 | Method and device for sharing content |
| CN103473963A (en) * | 2013-09-26 | 2013-12-25 | 苏州阔地网络科技有限公司 | Synchronous classroom processing method and system |
| CN103473963B (en) * | 2013-09-26 | 2015-07-15 | 苏州阔地网络科技有限公司 | Synchronous classroom processing method and system |
| CN104580308A (en) * | 2013-10-21 | 2015-04-29 | 中兴通讯股份有限公司 | Virtual desktop reappearing and pushing method and device and virtual desktop system |
| CN103780348B (en) * | 2014-01-23 | 2017-05-10 | 北京邮电大学 | DCS satellite link downlink data acknowledgement frame transmission method |
| CN103780348A (en) * | 2014-01-23 | 2014-05-07 | 北京邮电大学 | DCS satellite link downlink data acknowledgement frame transmission method |
| CN103795614A (en) * | 2014-03-10 | 2014-05-14 | 上海四方信息技术股份有限公司 | Instant mobile communication system and method |
| CN103795614B (en) * | 2014-03-10 | 2016-09-21 | 上海天赐北斗通信科技有限公司 | A kind of instant mobile communication system and communication means thereof |
| CN104065646A (en) * | 2014-06-04 | 2014-09-24 | 广州华多网络科技有限公司 | Online class fault processing method, device and system |
| CN104065646B (en) * | 2014-06-04 | 2017-05-17 | 广州华多网络科技有限公司 | Online class fault processing method, device and system |
| CN105376201A (en) * | 2014-08-26 | 2016-03-02 | 天脉聚源（北京）教育科技有限公司 | Multimedia information interactive system and interactive method |
| CN105376201B (en) * | 2014-08-26 | 2018-07-24 | 天脉聚源（北京）教育科技有限公司 | A kind of interaction of multimedia information system and exchange method |
| CN104320405B (en) * | 2014-11-06 | 2017-09-29 | 中国电子科技集团公司第五十四研究所 | A kind of upper optimization method suitable for star-like satellite network |
| CN104320405A (en) * | 2014-11-06 | 2015-01-28 | 中国电子科技集团公司第五十四研究所 | Internet surfing optimization method applicable to star satellite network |
| CN104882037A (en) * | 2015-06-02 | 2015-09-02 | 阔地教育科技有限公司 | Live-recorded broadcast interaction classroom system |
| CN106330929A (en) * | 2016-08-30 | 2017-01-11 | 四川教云网络科技有限公司 | Interactive education system based on two-way communication satellite and working method thereof |
| CN106330929B (en) * | 2016-08-30 | 2023-05-12 | 四川教云网络科技有限公司 | Interactive education system based on two-way communication satellite and working method thereof |
| CN106781758A (en) * | 2016-12-27 | 2017-05-31 | 深圳市汇龙建通实业有限公司 | A kind of Intelligent campus management system |
| CN108269438A (en) * | 2018-02-09 | 2018-07-10 | 河南理工大学 | A kind of network training education apparatus |
| CN108965786A (en) * | 2018-07-25 | 2018-12-07 | 深圳市异度信息产业有限公司 | A kind of electronic whiteboard content sharing method and device |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN1472713A (en) | Satellite multimedium bidirectional long-range real-time teaching systems | |
| CN101872555B (en) | Real-time interactive teaching system based on application-layer multicast services | |
| CN101873219B (en) | System for live broadcast of video conference on basis of application-layer multicast services | |
| CN103118074A (en) | Network modularization distance education training system based on extensible messaging and presence protocol (XMPP) | |
| CN109698818B (en) | Method and device for acquiring online user and cross-streaming media communication | |
| CN102254461A (en) | All-media remote training system based on unified communication | |
| JP4292998B2 (en) | Synchronization control method, communication synchronization control device, and bidirectional communication system | |
| Langi | Implementing ICT in primary schools in Keerom-Papua | |
| Quemada et al. | Isabel: an application for real time collaboration with a flexible floor control | |
| Wu et al. | Construction of Wireless Sensor Network Video Surveillance System for Multimedia Classroom Education and Teaching under 5G Communication Network | |
| CN100542099C (en) | A kind of multipoint control unit and based on the shared method and the conference system of IP network | |
| Mauthe et al. | Multimedia group communications: towards new services | |
| Che et al. | SameView: a large-scale real-time interactive e-learning system based on TORM and AMTP | |
| Balikhina et al. | Distributed virtual environments-An active future? | |
| CN1214602C (en) | Data meeting operation system and method | |
| Akintola et al. | Design & Development of Multimedia Network System for e-Learning in Nigeria Universities | |
| Zhao et al. | SkyClass: A large-scale mobile learning system for heterogeneous clients | |
| TWI234947B (en) | Network broadcasting system and method | |
| Quemada et al. | Tele-service creation with ISABEL in a heterogeneous network environment | |
| Katrinis et al. | Multi-source multimedia conferencing over single-source multicast (extended version) | |
| Li | Research on 5G+ Interactive Teaching Implementation Plan | |
| Swe et al. | Clasroom Shared Whiteboard System using Multicast Protocol | |
| Quemada et al. | Isabel: An application for real time audience interconnection over the internet | |
| Ørbæk | An experimental system for distributed classroom education | |
| Galajda et al. | Infrastructure for packet based e-learning services provided via satellite |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C12 | Rejection of a patent application after its publication | ||
| RJ01 | Rejection of invention patent application after publication |