KR100525175B1 - Vod service method making use of dual multicast transmission channel - Google Patents

Abstract

The present invention relates to a multicast video on demand (VOD) broadcasting service method using dual channels. More particularly, the present invention relates to a VOD using a multicast transmission method in which a plurality of users can simultaneously receive video data. In a broadcasting system, a user receives a predetermined amount of data after the data being reproduced in a backup channel while playing a predetermined amount of data stored in the broadcast channel or receiving a predetermined amount of data through a regular channel in real time. And store the predetermined amount of data after the data being reproduced through the backup channel during the playback by switching the stored amount of data after the reproduction of the data is completed through the backup channel. By repeating this process, the conventional VOD service VOD broadcasting service method that uses network and server resources efficiently and enables high quality VOD broadcasting service without any interruption by significantly reducing low quality problems such as waste of network and server resources and disconnection due to the above problems. It is about.

Description

Multicast video broadcasting service method using ＤｕａｌＣｈａｎｎｅｌ {VOD SERVICE METHOD MAKING USE OF DUAL MULTICAST TRANSMISSION CHANNEL}

The present invention relates to a multicast video on demand (VOD) broadcasting service method using dual channels. More particularly, the present invention relates to a VOD using a multicast transmission method in which a plurality of users can simultaneously receive video data. In a broadcasting system, a user receives a predetermined amount of data after the data being reproduced in a backup channel while playing a predetermined amount of data stored in the broadcast channel or receiving a predetermined amount of data through a regular channel in real time. And store the predetermined amount of data after the data being reproduced through the backup channel during the playback by switching the stored amount of data after the reproduction of the data is completed through the backup channel. By repeating this process, the conventional VOD service VOD broadcasting service method that uses network and server resources efficiently and enables high quality VOD broadcasting service without any interruption by significantly reducing low quality problems such as waste of network and server resources and disconnection due to the above problems. It is about.

In general, the VOD service applies video compression technology to database various video programs such as movies, and then, when general users select their desired video content using a user terminal such as a computer or a TV connected to an internet communication network, It is a communication service that enables a server to immediately transmit and enjoy video content desired by a user. The service is widely used in various fields such as film, broadcasting, online education, and video conferencing.

Looking at the characteristics of the VOD service, when the service user selects the desired video content, the video file is transmitted to the user terminal in the form of a bit stream and is based on a streaming technique that is played on the user terminal. The user can select the desired contents from the programs prepared without any time constraints and view them in a unique format that suits the user's taste, and can select playback, rewind, pause, and record during viewing as if operating a VCR.

In other words, even when the user selects the same movie, playback time is different from each other, and a video signal should be used exclusively by one user. As a method of providing the service, a unicast transmission method is generally a one-to-one data communication between a server and a user. This is used.

The unicast transmission method is a one-to-one communication method for transmitting data between a single sender and a single receiver, and most general Internet applications adopt the unicast transmission method.

However, in the case of the service using the transmission method, even if there are N users who select the same movie, the same video data must be repeatedly transmitted N times from the server's point of view. Therefore, the network efficiency decreases due to duplicate transmission of the same packet. There is a problem, and this problem becomes larger when the number of recipients increases.

In addition, the data demanded by the video is large and requires large server and network bandwidth to provide stable services. As a result, the number of users that can be used simultaneously is limited.

Therefore, the following several VOD service types are proposed and commercialized.

The first is a pay-per-view (PPV) service, in which a service provider provides only a user who applied for a video program such as a movie, and the user pays only a fee for the program. At this time, since all users who select the same movie are played at the same time point and all users play the same screen, it can be said to be a VOD service similar to broadcasting in that many users must watch.

The second is the NVOD (Near VOD) service, which does not provide a video program in real time as required by the viewer, but supplies the same program through several channels at short time intervals (typically 10 to 30 minutes). It is a service that has almost the same effect as the VOD service provided in real time by allowing the viewer to watch through a channel provided at a time required by the viewer.

The PPV and NVOD services do not provide a real-time interactive service, so the user cannot use the VCR function. However, the PPV and NVOD services use a multicast transmission method, which is a communication method in which a single sender establishes a 1: N channel with multiple clients and transmits data. This allows multiple users to share the same data at the same time, making it available to multiple users.

That is, the server manages users as a group so that the server transmits only one information stream in the form of a broadcast on the network using the group IP address, and the client receives the same stream broadcasted on the network individually. When using the transmission method, the number of clients using the service can be increased compared to the unicast transmission method. Since the server side transmits data packets to multiple receivers at once, the server resources can be effectively used, and data transmission is redundant. This minimizes the waste of network resources.

However, although the waste of server and network resources is considerably reduced by using the multicast transmission method, there are still many problems in the current VOD service.

In order to be broadcast in real time, the data stream must be continuously transmitted to the user, and at present, the amount of data received through the network rather than the amount of data required for playback is insufficient because there is not enough network infrastructure to process the large amount of data required for video transmission. In short, the real-time broadcast was not performed properly, and the intermittent phenomenon appeared.

Therefore, in order to broadcast in real time without interruption using a limited network infrastructure, most VOD service providers use a method of reducing the amount of video data transmitted.

Using this method, most of the VOD contents currently serviced are transmitted within approximately 300 Kbps, and the amount of data transmitted is closely related to the quality of the video contents, so that the VOD contents within 300 Kbps represent low quality video quality.

In addition, there is a data compression technique to reduce the amount of data while increasing the video quality, which is a large amount of data of the video content actually played, but using a high compression technology to reduce the amount of data transmitted over the network to ensure video quality That's how.

However, the high compression technology is also difficult to apply to the current real-time VOD service. As the amount of data transmitted through the network is greatly reduced by high compression technology, in order to restore the original video data amount, a large amount of processing is required in the CPU of the user terminal. A breakup phenomenon will appear.

In order to solve this problem, a method of transmitting and storing video data in advance to a user terminal before the user selects a playback as described below, when the user selects a playback, loads and plays the stored data so that a disconnection does not occur. Proposed.

The first is patent application 10-2001-7006601 (name of the invention: a standardizable system for video on demand). The proposed method is to pre-download the first part of the video content in the NVOD structure and store it in the user terminal. When the play is selected, the beginning portion of the video content stored in the user terminal is played out in advance, and the content information supplied through the NVOD structure is buffered in the user terminal, and the user terminal plays the NVOD from playing out the stored opening portion. The transition from supplying the buffered content information through the structure to playing out allows for standardization and minimizes the adverse effects of poor quality of IP network services.

However, such a prioritizable system for video-on-demand according to the prior art should be formed a continuous broadcast service channel at a time interval as much as the amount of data to be stored in advance in the user terminal. For example, in the case of a two-hour movie, the data of the opening portion of 10 minutes is transmitted in advance and stored in the user terminal. In order to broadcast in real time without interruption to the user even after the playback of the opening portion is completed, the broadcasting is performed in advance. Since 10 minutes of data stored in the opening part is reproduced and 10 minutes later, a total of 12 channels must be formed at 10 minute intervals, resulting in considerable waste of network and server resources.

In this case, if the amount of data of the opening part stored in advance in the user terminal is increased in order to reduce the number of broadcasting channels serviced for each movie, for example, if the 10 minute amount is 20 minutes, the number of broadcast channels serviced is the opening part. This can be reduced to half the amount of 10 minutes, but the amount of data to be stored in advance is doubled. Moreover, the standardizable system for video-on-demand according to the prior art does not know what content the user selects. Since 20 minutes of the preliminary portion of all video content is stored in the user terminal in advance, it causes waste of user terminal resources, and causes a lot of network traffic to receive the preamble of all the video content. do.

The second is patent application 10-2001-0058241 (name of the invention: video playback pause / release method in a video system), in the patent application, a method in which a client receives data simultaneously using a patching technique in an on-demand video system, In other words, when a new user selects a video program, the multicast video stream being transmitted through the regular channel is shared and temporarily stored on a disk, and a patching channel is formed separately to receive and play an unshareable initial video stream. When the playback of the stream is completed, a method of playing the data stored in the disc has been proposed.

This ensures seamless broadcasting of the multicast video data transmitted through regular channels, but the user transmits video data in real time through the patching channel by the time difference between when the user selects playback and playback of the regular channel. In addition, video data through a patching channel is transmitted to the user terminal and restored and reproduced at the same time, so that the streaming method is reproduced in the user terminal.

In addition, the regular channel is assigned to a channel using a multicast transmission method, but since each user selects playback, the patching channel is assigned a unicast channel for each user. This increases network traffic.

In the present invention, for example, when a movie content of 2 hours is serviced, when a new user selects to play a movie after 1 hour and 30 minutes is played on a regular channel, a new patching channel is formed to start from the beginning of the movie. At the same time, it receives data from 1 hour 30 minutes to 2 hours through the regular channel. The data received through the regular channel must be stored in the user terminal until the playback time reaches 1 hour 30 minutes. There is a problem in that a buffer of the user terminal needs to be additionally allocated.

In addition, if the buffer capacity of the user terminal cannot be further increased and a fixed capacity must be used, the amount of buffer available for data received through the patching channel is reduced by that amount, and it must be transmitted and stored through the regular channel rather than the buffer capacity of the user terminal. If the amount of data to be used is higher than the normal channel, the data may not be properly received, resulting in low quality problems such as dropping.

As described above, the proposed patent applications 10-2001-7006601 and 10-2001-0058241 also have not solved a low quality problem such as waste and disconnection of user terminal, server, and network resources.

The present invention has been proposed to solve the above problems, and in a VOD broadcasting system using a multicast transmission method in which a plurality of users can receive video data at the same time, the data stored for a predetermined amount of time is reproduced. Receives a certain amount of data after the data being played back to the backup channel and stores it in the user terminal during playback in real time while receiving a certain amount of data through the regular channel, and stored after the reproduction of the data is completed Receiving a predetermined amount of data after the data being reproduced during the playback by switching the predetermined amount of data through the backup channel and stored in the user terminal, and by repeating this process to the limit of server and network resources Eliminate the disconnection caused by The purpose is to provide a broadcast of image quality.

In order to achieve the above object, the multicast VOD broadcast service method using the Dual Channel according to the present invention, the first step of connecting to the service server; A second step of selecting contents to be watched from a list of VOD broadcasting contents provided by the service server; Registering information about a user who has selected content in the service server with a content user group; A fourth step of forming a regular channel or a backup channel for the VOD broadcast service; A fifth step of transmitting a predetermined amount of data at the beginning of the content to the registered user group through the regular channel or the backup channel before the normal broadcast time and storing the data in the user terminal; A sixth time for receiving a predetermined amount of data after the data being reproduced through the regular channel or the backup channel while reproducing the predetermined amount of data stored in the fifth step at a regular broadcast time and storing the data in the user terminal; step; After the reproduction of the data in the sixth step is completed, the predetermined amount of data after the data being reproduced during the playback by switching the predetermined amount of data stored in the sixth step to the regular channel or the backup channel. A seventh step of receiving the data and storing the received information in the user terminal; And an eighth step of repeating the seventh step until the broadcast content ends or until the service stop is requested.

The multicast VOD broadcasting service method using the dual channel according to the present invention includes a first step of connecting to a service server during a regular broadcasting time or broadcasting; A second step of selecting contents to be watched from a list of VOD broadcasting contents provided by the service server; Registering information about a user who has selected content in the service server with a content user group; A fourth step of forming a regular channel and a backup channel for the VOD broadcast service; Receiving a certain amount of data after the data that is being reproduced during the direct playback by transmitting a certain amount of data after the time to attempt to access through the regular channel through the backup channel to store in the user terminal 5 steps; After the reproduction of the data in the fifth step is completed, the predetermined amount of data after the data being reproduced is transmitted through the backup channel during the reproduction of the predetermined time amount of data stored in the fifth step. A sixth step of storing in the user terminal; And a seventh step of repeating the sixth step when the broadcast content ends or until a service stop is requested.

First, in order to enable a multicast VOD broadcasting service using a dual channel according to the present invention, the following items are required.

First, a service provider prepares a broadcast list of contents and broadcast time for each content in advance, and stores the content having a predetermined broadcast time in the form of a bit stream compressed and coded at a predetermined bitrate using a high compression technique. User groups must be set up.

In addition, a predetermined amount of video data transmitted through a regular channel and a backup channel, which are data transmission channels, allows a user terminal to store and restore data in the form of a compressed coded bit stream provided from a streaming server, thereby real-time broadcasting without interruption. It should be pre-set to the minimum amount possible to enable it.

The user terminal has a storage device capable of storing a predetermined amount of video data transmitted through the regular channel and the backup channel, and a terminal having a CPU suitable for restoring compression coded data provided from a streaming server. Should be

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a diagram illustrating a network configuration of a VOD broadcast service according to the present invention, FIG. 2 is a diagram schematically illustrating a channel configuration of a VOD broadcast service according to the present invention, FIG. 3A is a flowchart illustrating an operation procedure of a service server according to the present invention, and 3B is a flowchart illustrating an operation procedure of a user terminal according to the present invention. For reference, the same reference numerals shown in each drawing represent the same components.

As shown in FIG. 1, the multicast VOD broadcasting service network using the dual channel according to the present invention includes a plurality of user terminals 1, a network manager 2, a service server 3, and a streaming server 4. It is configured to include, and look at the components of the VOD broadcast service network as follows.

First, the user terminal 1 requests the service server 3 to provide the video content desired by the user according to the user's selection, and is a video program requested through the service server 3 and provided from the streaming server 4. As shown in FIG. 2, the user terminal 1 includes a buffer 1 11, a buffer 2 12 and a decoder (not shown in the drawing). Not included).

The buffer 1 11 and the buffer 2 12 store data transmitted from the streaming server 4 through the regular channel 33a and the backup channel 33b which will be described below. Buffer 1 (11) and buffer 2 (12) store data of the two buffers (11, 12) rather than dedicated storage for each of the regular channel (33a) and backup channel (33b). It is controlled to switch selectively depending on the presence or absence.

That is, when data transmitted and stored in the buffer 1 (11) through the normal channel 33a is being reproduced, data transmitted through the backup channel 33b is stored in the buffer 2 (12), and the buffer 1 (11). When the data reproduction of the data is completed and the reproduction of the data stored in the buffer 2 (12) starts, the data transmitted through the backup channel 33b thereafter is the buffer 1 (11) which does not have the stored data after the reproduction of the data is completed. ), And the process is repeated until the broadcast ends.

The decoder transmits the data stored in the buffer 1 (11) and the buffer 2 (12) transmitted from the streaming server 4, that is, the data in the form of a bit stream compressed and coded at a predetermined bit rate using a high compression technique. The terminal 1 restores the original signal before playback.

Here, the user terminal 1 may be a set top box (STB), a TV, a computer, or the like, which is connected to an internet communication network and enables bidirectional communication.

The network manager 2 is an interface connecting the plurality of user terminals 1, the service server 3, and the streaming server 4, and transmits various request signals requested from the plurality of user terminals 1 to the service server 3. ), And transmits the video program data provided from the streaming server 4 to the plurality of user terminals 1 requesting the service based on the service request information requested through the service server 3.

The service server 3 connected to the network manager 2 is a service information management and control system of the entire VOD broadcast service system. The service server 3 is linked with the streaming server 4, and the service manager 31 and the group manager 32 are connected to the network manager 2. And a channel manager 33 and a customer DB manager (not shown in the figure).

The service manager 31 is a main component that manages and controls the VOD broadcast service system. The service manager 31 is interworked with the group manager 32, the channel manager 33, and the customer DB manager, and the group manager 32. , The channel manager 33 and the customer DB manager all operate according to the control command of the service manager 31.

In addition, the service manager 31 also manages the streaming server 4 to be described below to control the production of content according to the broadcast time schedule and to transmit the content to a user group requesting the service according to the broadcast time.

The service manager 31, which is a main component in charge of management and control of the VOD broadcast service, is configured to provide various services from a plurality of user terminals 1 such as STBs, computers, and TVs connected to the Internet through the network manager 2. Upon receiving the request signal, a plurality of users requesting the same service are set as a group, a channel for providing a service to the group is established, and the network administrator is sent to the streaming server 4 by requesting the group's request information. Through (2), a plurality of users registered in the group are instructed to transmit the requested video content.

The group manager 32 sets a user group for each of the contents according to the broadcasting time for each content arranged by the VOD broadcast service provider, and receives the user group from the plurality of user terminals 1 received through the network manager 2. The users who requested the content are registered in the user group for each content according to the request information.

The channel manager 33 forms a normal channel 33a and a backup channel 33b, which are two multicast channels for providing a VOD broadcast service to the content group. The regular channel 33a is a channel for transmitting data in accordance with a regular broadcast time so that users who want to watch the broadcast can receive a broadcast service in real time, and the backup channel 33b uses the regular channel 33a. It is a channel that sends a predetermined amount of data after the data transmitted in advance to be stored in the user terminal 1 and the user can receive the VOD broadcast service without interruption by reproducing the data stored in the user terminal 1 in advance. .

Here, when the interval between video data transmission time sent through the regular channel 33a and the backup channel 33b is A, A is a predetermined bit rate provided by the user terminal 1 from the streaming server 4. It is preferable that the time interval A = 5 minutes be set in advance as a minimum time for restoring the data in the form of a compression-coded bit stream to enable real-time broadcasting without interruption.

The customer DB manager is a component that stores and manages service request information from the user terminal 1. By using the information, it is possible to have an opportunity for programming such as broadcasting which is more accessible to customers.

The streaming server 4 transmits the video content requested by the general users to the users who requested the service using the user terminal 1 such as STB, computer and TV connected to the Internet communication network in the VOD broadcasting service system. The service information requested through the service server 3 is searched in the service program DB stored in the streaming server 4, and the corresponding information retrieved from the service manager DB is formed by the channel manager 33 through the network manager 2. Send to them.

The streaming server 4 includes a DB manager 41 and an encoding server 42. The encoding server 42 reduces the amount of data transmitted over a network by using an analog A / V source program to reduce video quality. By using a high compression technique as a guarantee method to make a program in the form of a bit stream compression-coded at a predetermined bitrate, the DB manager 41 is a bit stream compression-coded at a predetermined bitrate through the encoding server 42 When the program is stored and managed to receive service request information through the service manager 31 of the service server 3, the stored service program DB is searched and the requested video content is transmitted to the users through the network manager 2. Send to.

3A is a flowchart showing an operation procedure of the service server 3 according to the present invention, and FIG. 3B is a flowchart showing an operation procedure of the user terminal 1 according to the present invention. The steps until the user requests the service of the VOD broadcast content that the user wants to view through the user terminal 1 and the like to view the selected content.

First, referring to FIG. 3B, a user who wants to receive a service attempts to connect to a VOD broadcast service server 3 using a user terminal 1 such as an STB, a computer, and a TV, which can be connected to an internet communication network. (S60)

The user terminal 1 generates a service access signal selected by the user and transmits it to the network manager 2, and the network manager 2 transmits a signal received from the user terminal 1 to the VOD broadcast service server 3. The user terminal 1 and the service manager 31 of the service server 3 are connected to each other by a signal to be connected to the service terminal 3.

The service manager 31 provides a list of VOD broadcast contents to the user, and the user selects the VOD broadcast service contents that the user wants to watch from the provided list (S61).

Here, before the service manager 31 provides the VOD broadcast content list to the user who has requested access to the VOD broadcast service server 3, the service manager 31 is assigned with the ID of the user who is granted at the time of subscription through the customer DB manager. And if the user confirms the password or requests a new service, it is preferable to proceed with the preliminary procedures necessary for using the service, such as subscription, payment information.

In addition, the service manager 31 sets a user group for each broadcast content in advance by organizing the broadcast list of the content and the broadcast time for each content in advance (S50).

In the process, when the user selects the VOD broadcast service content that the user wants to watch, the user terminal 1 generates a service request signal selected by the user and transmits it to the network manager 2, and the network manager 2 The signal received from the user terminal 1 is identified as a signal for requesting the VOD broadcast service and transmitted to the service manager 31 for the VOD broadcast service.

The service manager 31 analyzes the signal and extracts the service request information of the user, that is, the request / release information of the service, the user ID, the IP address, and the requested broadcast content information. If so, instructs the group manager 32 to register the user in the content service group.

When the group manager 32 registering the user to the content service group requested by the user reports to the service manager 31 that the group registration is completed (S51), the service manager 31 informs the channel manager 33 of the group manager 32. Based on the group information, two multicast channels between the streaming server 4 and the users registered in the group, that is, the regular channel 33a for broadcasting in real time, and previously transmitted and stored to the user terminal, are not interrupted to the user. Instructs to form a backup channel 33b for broadcasting.

Here, as described above, the interval A of the video data transmission time sent through the regular channel 33a and the backup channel 33b is a bit compression-coded by a user terminal at a predetermined bitrate provided from the streaming server 4. It is set to the minimum time for recovering the data in the stream form to enable real-time broadcasting without interruption.

The channel manager 33 is a regular for broadcasting two multicast channels, i.e., in real time, between the streaming server 4 and the network manager 2 and between the network manager 2 and the user terminal 1 registered in the group. A channel 33a and a backup channel 33b for transmitting to the user terminal in advance and storing the broadcast seamlessly to the user are formed. The network manager 2 causes the network manager 2 to transmit the regular channel 33a and the backup channel 33b. Instructs to relay (S52).

The channel manager 33 reports to the service manager 31 that channel formation has been completed, and the service manager 31 generates a signal by integrating group information and channel information for a specific broadcast content and then streams it. Send to the server 4 to instruct the streaming server 4 to transmit to the user requesting the corresponding broadcast content using information in which the group information, channel information and the like are integrated.

Then, the streaming server 4 searches for the broadcast content DB (S53), sends the broadcast content to the network manager 2 through a channel formed between the streaming server 4 and the network manager 2, the network The manager 2 relays the contents through a channel formed between the network manager 2 and the users registered in the group.

Here, the streaming server 4 transmits the broadcast content to the registered user terminal 1 in advance through the backup channel 33b of the two channels formed through the channel manager 33 before the broadcast time to the user terminal ( 1) can be stored in the buffer 1 (11) or buffer 2 (12) (S55), and during the normal broadcast time is transmitted in real time through the regular channel 33a and at the same time through the backup channel (33b) 33a) and transmits the broadcast content after the interval A minutes of the transmission time of the data set between the backup channel 33b (S57), and the service manager 31 checks the transmission time and the end time of the broadcast content to complete transmission and termination. (S54, S56, S58, S59)

In this case, the broadcast content provided from the streaming server 4 through the regular channel 33a and the backup channel 33b uses a high compression technology that is a method of guaranteeing video quality by reducing the amount of data transmitted through a network. It has a form of a bit stream compression-coded with a bit rate, and is stored and reproduced in the buffer 1 11 and the buffer 2 12 of the user terminal 1.

In the case of a user who applied for the service before the regular broadcast time (S62), the A-minute video data of the beginning of the video content transmitted through the backup channel 33b in advance A minute before the normal broadcast time (S63) is transmitted to the user terminal 1. Since the data is stored in the buffer 1 (11) or the buffer 2 (12) (S64), if the data is stored in the buffer 1 (11) (S65, S66-1) during the normal broadcast time the user terminal (1) A minute after A minute of data stored in the buffer 1 (11) transmitted through the backup channel 33b to the buffer 2 (12) while simultaneously restoring and reproducing the data stored in the buffer 1 (11) using a decoder of When the amount of data is stored (S67-1) and the reproduction of the data stored in the buffer 1 (11) is completed, the data stored in the buffer 2 (12) is restored and reproduced (S65, S66-2, S67-2) ), By repeating the above process, real-time broadcasting is performed without interruption to the user. To lose.

In the exemplary embodiment of the present invention, the video data transmitted through the backup channel 33b is previously stored in the buffer 1 11 of the user terminal 1, but the data may be stored in the buffer 2 12. (S65, S66-2), in this case, the data stored in the buffer 2 (12) transmitted through the backup channel 33b to the buffer 1 (11) while restoring and reproducing the data stored in the buffer 2 (12). A minute amount of data after A minute is stored (S67-2), and when the reproduction of the data stored in the buffer 2 (12) is completed, the data stored in the buffer 1 (11) is switched to restore and reproduce (S65, S66). -1, S67-1), by repeating the above process to ensure that the user is a real-time broadcast without interruption.

In addition, in the case of the user who applied for the service after the regular broadcast time or the broadcast starts (S62), as described above, the procedure for requesting the service by connecting to the initial service server 3 is the same (S60, S61), but in advance Since the data is transmitted through the backup channel 33b and is not stored in the buffer 1 11 or the buffer 2 12 of the user terminal 1 (S65, S66-2, S68), it is transmitted through the regular channel 33a. The data is stored in buffer 1 (11), restored and reproduced through a decoder in real time, i.e., after a minute of data transmitted through the regular channel 33a to the backup channel 33b at the same time using broadcast contents by a streaming technique. Receives the A-minute broadcast content and stores it in buffer 2 (S69), and when the reproduction of the data stored in the buffer 1 (11) is completed, the data stored in the buffer 2 (12) is restored and reproduced. (S65, S66-2, S67-2), that is, the user selects playback After A minute of the point, the user can reproduce the data transmitted and stored through the backup channel 33b, and then repeats the processes of S65, S66-1, and S67-1 so that the user can have a real-time broadcast without any problem. do.

In the above embodiment, the video data transmitted through the regular channel 33a may be stored in the buffer 2 12 and reproduced in real time. In this case, the data transmitted through the regular channel 33a may be stored in the buffer 2 12. It restores and reproduces through the storage and decoder to use broadcast contents in real time, and receives A-minute data after A-minute of the data transmitted through the regular channel 33a to the backup channel 33b and receives the buffer content in the buffer 1 (11). When the reproduction of the data stored in the buffer 2 (12) is completed and stored, the data stored in the buffer 1 (11) is restored and reproduced, and by repeating this process, the user is provided with a real-time broadcast without any interruption. .

Although not shown in FIGS. 3A and 3B, when the user who is watching the broadcast requests the service to be stopped during viewing, the procedure is the same as the service request procedure, and the user terminal 1 requests the service to be released. Generates a signal to be transmitted to the network manager (2).

The network manager 2 recognizes the signal received from the user terminal 1 as a signal for the VOD broadcast service and transmits the signal to the service manager 31 for the VOD broadcast service.

After analyzing the signal, the service manager 31 extracts the service request information of the user, that is, the request / release information of the service, the user ID, the IP address, and the requested service content information, and then releases the specific broadcast content service. If a request is made, the group manager 32 instructs the content service group to deregister the user and the channel manager 33 to release channel formation for the user based on the unregistered group information of the user. The transmission of the broadcast content is stopped by the user requesting the release of the service.

Hereinafter, a user type in a multicast VOD broadcasting service using a dual channel according to the present invention will be described.

First, in the embodiment of the present invention, the broadcast content "to her" is broadcast from 10:00 to 12:00 on Thursday night, and the interval of transmission time of video data transmitted through the regular channel 33a and the backup channel 33b. Let A be 5 minutes, and let it be divided into 0A, 1A, 2A, ..., and 24A from the beginning of the content.

The first type is a user requesting a service at least 5 minutes before the broadcast time, and the above-mentioned video data is transmitted to the user through the backup channel 33b from 9:55 minutes as described above. Video data up to 1A is stored in buffer 1 (11) of user terminal (1).

When the regular broadcast time is 10:00, the streaming server 4 transmits data of 1A to 2A to the backup channel 33b. The user terminal 1 which has selected the service in advance is the user terminal 1 Reproduces data from 0A to 1A stored in buffer 1 (11) at the same time and stores data from 1A transmitted through backup channel 33b in buffer 2 (12) of user terminal (1). When the reproduction of the data stored in the buffer 1 (11) is completed, the data stored in the buffer 2 (12) is switched to restore and reproduce. Subsequently, the buffer 1 (11) and the buffer 2 (12) alternately play its role while repeating the process of playback and storage until the end of the broadcast, so that the user can achieve a real-time broadcast without a phenomenon.

The second type is a user who requests a service during a regular broadcast time or during a broadcast. For example, when a user requests a service at 10:30, the user enters buffer 1 (11) or buffer 2 (12) of the user terminal 1 in advance. Since there is no stored broadcast data, the service group registration and channel formation through the service server 3 allows the user to receive video data from 6A to 7A through the regular channel 33a and store it in the buffer 1 11 and play it back in real time. At the same time, the data of 7A to 8A is received through the backup channel 33b and stored in the buffer 2 (12) of the user terminal 1, and when the reproduction of the data stored in the buffer 1 (11) is completed, the buffer To restore and play back the data stored in 2 (12), after that, as in the first type, buffer 1 (11) and buffer 2 (12) alternately switch their roles, and play and save until the broadcast ends. Repeat the process of As users and become a real-time broadcast made without stuttering.

That is, from 10:30 to 10:35 when the user starts the service, the data received through the regular channel 33a is reproduced and broadcasted in real time, but from 10:35, the data stored in the user terminal 1 in advance. Because it restores and plays using, you can receive service while receiving data without interruption in real time.

In the above, a preferred embodiment of the multicast VOD broadcasting service method using the dual channel according to the present invention has been described. However, the present invention is not limited thereto, and the claims and the detailed description of the invention and the accompanying drawings are described. It is possible to carry out various modifications within the scope, which also belongs to the present invention.

As described above, the multicast type VOD broadcasting service method using the dual channel according to the present invention may be performed while playing back a predetermined amount of data stored in a predetermined time or receiving a predetermined amount of data through a regular channel and playing the data in real time. Receives a certain amount of data after the data being reproduced in the backup channel and stores it in the user terminal, and after the data being reproduced during the reproduction by switching the predetermined amount of data stored after the reproduction of the data is completed Receives a certain amount of data through the backup channel and stores it in the user terminal, and repeats the process of reproducing and storing the data without loss of data according to the network environment, and also the time required to restore the data High quality without interruption To enable VOD broadcast services.

In the multicast VOD broadcasting service method using the dual channel according to the present invention, the users are managed as a group so that the server transmits only one information stream in the form of a broadcast on the network using the group IP address, and the client is on the network. By using the multicast transmission method that receives the same streams individually broadcasted separately, the server and network resources can be minimized and used efficiently.

1 is a diagram illustrating a network configuration of a VOD broadcast service according to the present invention.

2 is a diagram schematically illustrating a channel configuration of a VOD broadcast service according to the present invention.

3A is a flowchart illustrating an operation procedure of a service server according to the present invention.

3B is a flowchart illustrating an operation procedure of a user terminal according to the present invention.

Explanation of symbols on main parts of drawing

 1: user terminal 11: buffer 1

12: Buffer 2 2: Network Manager

 3: service server 31: service manager

32: group manager 33: channel manager

 4: streaming server 41: DB manager

42: encoding server

Claims (4)

delete In the multicast VOD broadcasting service method using Dual Channel, A first step of connecting to a service server during a broadcast in which the predetermined broadcast time has elapsed; A second step of selecting contents to be watched from a list of VOD broadcasting contents provided by the service server; Registering information about a user who has selected content in the service server with a content user group; A fourth step of forming a regular channel and a backup channel for the VOD broadcast service; Receiving a certain amount of data after the data that is being reproduced during the direct playback by transmitting a certain amount of data after the time to attempt to access through the regular channel through the backup channel to store in the user terminal 5 steps; After the reproduction of the data in the fifth step is completed, the predetermined amount of data after the data being reproduced is transmitted through the backup channel during the reproduction of the predetermined time amount of data stored in the fifth step. A sixth step of storing in the user terminal; And And a seventh step of repeating the sixth step when the broadcast content ends or until the service stop is requested. The method of claim 2, The normal channel and the backup channel is a VOD broadcast service method characterized in that for transmitting data using a multicast transmission method The method of claim 2, The VOD broadcasting service method, characterized in that a predetermined amount of time of video data transmitted through the regular channel and the backup channel is preset to a minimum amount of real time broadcasting without interruption by storing and restoring the data at the user terminal.