JPH11122599A - Video on-demand system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent delayed reproduction of video data by providing a means that discriminates a band required by video data selected by the user to decide a multi-link in use so as to distribute the video data stably even when an amount of the video data is increased. SOLUTION: A video server 2 uses a server control means 13 to recognize a RAS multi-link set up with a video client device. The server control means 13 obtains a total band width of the setup RAS multi-link. Then optimum data among video data stored in advance are decided from the obtained band width and a video data name. A video data management means 16 extracts the decided video data from a storage device 11 and the data are sent to the RAS multi-link from a communication port 10 via a multi-link control means 12. The video client device receives the video data from the RAS multi-link to reproduce the video data.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video-on-demand system, and more particularly to a video client device (video user terminal) capable of reproducing video and audio by using a plurality of remote access service (RAS) lines simultaneously. And a video on demand system.

[0002]

2. Description of the Related Art Conventionally, video-on-demand (VO)
D) The system has a plurality of video client devices and a video server communicating over network media. The video client device sends a digital video data distribution request via a network medium, and receives the video data to display the content. The video server distributes video data based on video data distribution requests from a plurality of video client devices.

One example of a conventional VOD system is disclosed in
No. 8907. In this VOD system, video data is divided into segments and stored in a disk device, which is distributed to a terminal device having a buffer memory and a decompressor to provide video and audio to a user. Another example of a conventional VOD system is described in JP-A-8-46949. In this VOD system, a plurality of video transmission devices are prepared in advance, a user terminal device is connected to each of them, and video data of a plurality of storage devices is transmitted to these. These storage devices are connected to a plurality of video transmission devices via a network, and transmit video data to a user terminal device via the video transmission devices.

[0004] A method of connecting to a remote video server by dial-up (incoming connection) of a telephone line is called "remote access". One form is the US Mi
OS (Operating System) called WindowsNT4.0 (trade name) of Microsoft Corporation
Remote access service (RAS) implemented in software. Also, a system that performs a high-speed transfer by regarding a plurality of RAS lines collectively as a single virtual line is referred to as “RAS multilink”. One form is RFC1717, RFC1990 and RFC1993.
In "PPP Multilink Protoco
l ".

[0005] As shown in FIG.
A VOD system having a plurality of video client devices 101, a video server 102, and an RAS multilink 103 connecting them is described.
The RAS multilink 103 is an analog telephone line 1
04, an ISDN line 105, a wireless line 106, and the like. The VOD system fragments data and sends it out as packets to a plurality of different lines, and restores the data. At this time, the lines to be combined are not limited to the same type and the same speed, and the RAS lines are used by distributing packets according to the degree of congestion. Such RAS multilink is a technique for improving the bandwidth (bandwidth) by simultaneously using a plurality of RAS lines. That is, the RAS multilink makes it possible to increase the data transfer amount per unit time by combining a plurality of lines.

[0006] RFC 1993 describes a mechanism for increasing or decreasing the number of RAS multilinks as needed. RAS multilink is Windows NT 4.0
The user has multiple physical devices
By designating a dial-up connection to the S multilink, a plurality of lines can be apparently used simultaneously as one line. Video client device to R
By connecting a video server using the AS multilink, a VOD system can be constructed.

[0007]

However, in the conventional VOD system, when the amount of video data increases, the distribution of the video data is interfered due to the contention of the bandwidth within the same multilink. There is a problem that reproduction is delayed.

An object of the present invention is to provide a VOD system capable of stably delivering video data even when the amount of video data increases and preventing a delay in reproduction of the video data.

[0009]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, a first aspect of the present invention is a video-on-demand having a video server and a video client device communicating via a multilink capable of providing a remote access service. The system is characterized in that it has means for determining a band required by video data selected by a user and determining a multilink to be used.

[0010] Further, in the video-on-demand system, the video server stores in advance video data having a plurality of bandwidths corresponding to a bandwidth which may be used between the video client device and the distribution request. A storage device to be stored.

According to a second aspect of the present invention, there is provided a video-on-demand system having a video server and a video client device communicating via a multilink capable of providing a remote access service, wherein the video client device is selected by a user. Client control means for judging a band required by the video data and determining a multilink; bandwidth multilink determination table means for determining a multilink corresponding to the bandwidth required by the video data; Multi-link control means for requesting a multi-link in response to the determination of the width multi-link determination table means, wherein the video server calculates a bandwidth to be used between the video client device and the distribution request. And said means calculated by this means And having a means for selecting determines a video data that matches the command width.

Further, in the video-on-demand system, the video server stores in advance video data having a plurality of bandwidths corresponding to a bandwidth that may be used between the video client device and the distribution request. A storage device to be stored.

According to a third aspect of the present invention, there is provided a video-on-demand system having a video server and a video client device communicating via a multilink capable of providing a remote access service, wherein the video client device is selected by a user. Client control means for judging a band required by the video data and determining a multilink; bandwidth multilink determination table means for determining a multilink corresponding to the bandwidth required by the video data; Multi-link control means for requesting a multi-link in response to the determination of the width multi-link determination table means, the video server comprising: a multi-link control means for securing a multi-link established by the video client device; This multilink system A server control means for generating an inquiry signal in response to the secured multilink information from the means, and a bandwidth used between the video client device of the distribution request when receiving the inquiry signal from the server control means. Multilink bandwidth calculation table means for calculating, bandwidth video data determination table means for determining video data matching the bandwidth calculated by the multilink bandwidth calculation means, and bandwidth video data determination table means Video data management means for extracting video data from the storage device in response to the determination of

Further, in the video-on-demand system, the video server stores in advance video data having a plurality of bandwidths corresponding to a bandwidth that may be used between the video client device and the distribution request. A storage device to be stored.

[0015]

Next, embodiments of the present invention will be described in detail with reference to the drawings. As shown in FIG. 1, a VOD system according to an embodiment of the present invention has a plurality of video client devices 1 and a video server 2. The plurality of video client devices 1 and the video server 2 communicate via an RSA multilink 3 which can provide a remote access service. The video client device 1 sends a video data distribution request, and
The video data is received and its video and audio are reproduced.

As shown in FIG. 2, the video client device 1 includes a client processing device 4, a communication port 5 connected to the client processing device 4,
An OS user interface (not shown) connected to the client processing device 4; The client processing device 4 communicates via the communication port 5
It is connected to SA multilink 3. The client processing device 4 includes a client control unit 6, a bandwidth multi-link determination table 7, and a multi-link control unit 8. The operation of the client processing device 4 is controlled by a video client program.

The client control means 6 receives a request for reproducing video data from the OS user interface. The type of video data depends on the video quality.
G1 (〜1.5 Mbps) and MPEG2 (〜6 Mbps)
ps). The client control means 6 determines the video quality of the requested video data, for example, the MPE.
If it is G1, an inquiry is made to the bandwidth multilink determination table 7 to secure a 1.5 Mbps band.

The bandwidth multilink determination table 7
Determines the combination of multilinks for the inquired bandwidth, and replies to the client control means 6. In the bandwidth multi-link determination table 7, for example, data as shown in FIG. 4 is stored.
The client control means 6 instructs the multilink control means 8 to open the RAS multilink 3 in response to the response from the bandwidth multilink determination table 7. The multi-link control means 8 transmits the designated RAS multi-link 3
RAS is executed and RAS multilink 3 is established.

Next, the video server 2 will be described with reference to FIG. As shown in FIG. 3, the video server 2 includes a server processing device 9 and the server processing device 9.
And a storage device 11 connected to the server processing device 9. The server processing device 9 communicates via a communication port 10 with RSA
It is connected to multilink 3. The server processing device 9 includes a multilink control unit 12 and a server control unit 1
3, a multi-link bandwidth calculation table 14, a bandwidth video data determination table 15, and video data management means 16. The server processing device 9 includes:
The operation is controlled by the video server program.

The multi-link control means 12 secures the RAS multi-link 3 established by the video client device 1, and secures the secured RAS multi-link 3.
Is notified to the server control means 13. The server control means 13 provides an inquiry signal for inquiring the multilink bandwidth calculation table 14 to calculate the total bandwidth for the input multilink. . The reason is that since the RAS multilink 3 for video distribution is reserved in advance, other communication traffic uses the RAS multilink 3. The multilink bandwidth calculation table 14 stores, for example, data as shown in FIG. The multi-link bandwidth calculation table 14 calculates the total bandwidth of the RAS multi-link 3 with the video client device 1 as the connection request source when receiving the inquiry signal from the server control means 13 and calculates this as the bandwidth video data determination table 15. Output to

The bandwidth video data determination table 15 stores, for example, data as shown in FIG.
The bandwidth video data determination table 15 changes the bandwidth in advance for the input bandwidth and the video data requested to be distributed (for example, for 4.4 Kbps,
For 28.8Kbps, For 33.6Kbps, 1.5Mb
Among the stored video data, video data that can be transmitted with the calculated bandwidth is determined, and a response is sent to the server control means 13.

The server control means 13 instructs the video data management means 16 to transmit the video data. The video data management means 16 takes out the input video data from the storage device 11 and sends it to the multilink control means 12. The storage device 11 stores in advance video data having a plurality of bandwidths corresponding to bandwidths that may be used between the video client device 1 and the video server 2.

Next, the operation of the embodiment of the present invention will be described with reference to FIG. The video data name given from the OS user interface is given to the client control means 6 (step A1). The client control means 6 recognizes the bandwidth required by the video data, determines the available multilink by assigning the bandwidth to the bandwidth multilink determination table 7 for determining the multilink, and secures it ( Step A2). The client control means 6 gives an instruction to open the secured RAS multilink 3 to the multilink control means 8. The multilink control means 8 connects the RAS multilink 3 to the video server 2 by a dial-up connection (step A3).

The video server 2 recognizes the RAS multilink 3 established with the video client device 1 by the server control means 13 (step B1). The server control means 13 obtains the total bandwidth of the established RAS multilink 3 (step B2). The server control means 13
From the obtained bandwidth and the video data name, the optimum one of the video data stored in advance is determined (step B3). The determined video data is taken out of the storage device 11 by the video data management means 16 and transmitted to the RAS multilink 3 from the communication port 10 via the multilink control means 12 (step B4). The video client device 1 receives the video data from the RAS multilink 3 (Step A4) and plays back the video data (Step A5).

Next, specific examples of the embodiment of the present invention will be described. Referring to FIG. 7, for example, when a user enters a 2M
bps bandwidth and FIL. It is assumed that a distribution of video data called MPG is requested. The client control means 6
In order to construct a 2 Mbps multilink based on the bandwidth of 2 Mbps, the bandwidth multilink determination table 7 is searched to determine a multilink to be used. Here, it is assumed that it is determined that 30 ISDN lines of 64 Kbps can be used. In this case, the multilink control means 6 of the video client device 1 starts the connection of the RAS multilink 3 and establishes the RAS multilink 3 with the video server 2.

When the RAS multilink 3 is established with the video client device 1, the video server 2 obtains the total bandwidth from the multilink bandwidth calculation table 14. Here, it is required to be 2 Mbps. Next, the server control means 13 determines an optimum one of the video data stored in advance from the obtained bandwidth and the video data name.

The video server 2 has 33.6 Kbp in advance.
s, 128 Kbps, and 2 Mbps FIL. MPG
Is stored. Here, since the data is stored in the corresponding bandwidth, the use of the 2 Mbps video data is determined by the bandwidth video data determination table 15. The corresponding video data is taken out of the storage device 11 by the video data management means 16 and transmitted to the RAS multilink 3. The video client device 1 receives video data from the RAS multilink 3 and plays back the video data.

[0028]

According to the VOD system of the present invention, since the optimum RAS multilink for the video data to be distributed is determined and secured in advance, it is possible to reduce the interference with the distribution of video data of other communication traffic. Since it is possible, even when the amount of video data increases, the video data can be stably delivered and the delay of the reproduction of the video data can be prevented.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a video on demand system of the present invention.

FIG. 2 is a block diagram illustrating a video client device of the video on demand system of FIG.

FIG. 3 is a block diagram showing a video server of the video-on-demand system of FIG. 1;

FIG. 4 is a diagram illustrating a bandwidth multilink determination table of the video client device of FIG. 2;

FIG. 5 is a diagram illustrating a multi-link bandwidth calculation table of the video server in FIG. 3;

FIG. 6 is a diagram illustrating a bandwidth video data determination table of the video server of FIG. 3;

FIG. 7 is a flowchart illustrating an operation of the video-on-demand system in FIG. 1;

FIG. 8 is a conceptual diagram illustrating a conventional video-on-demand system.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Video client device 2 Video server 3 RAS multilink 4 Client processing unit 5 Communication port 6 Client control means 7 Bandwidth multilink determination table 8 Multilink control means 9 Server processing unit 10 Communication port 11 Storage device 12 Multilink control means 13 Server control means 14 multilink bandwidth calculation table 15 bandwidth video data determination table 16 video data management means

Claims (6)

[Claims] 1. A video-on-demand system having a video server and a video client device communicating via a multi-link capable of providing a remote access service, wherein the multi-link determines and uses a bandwidth required by video data selected by a user. A video-on-demand system comprising means for determining 2. The video-on-demand system according to claim 1, wherein the video server has a plurality of bandwidths corresponding to a bandwidth to be used with the video client device of the distribution request. A video-on-demand system comprising a storage device for storing data in advance. 3. A video-on-demand system having a video server and a video client device communicating over a multilink capable of providing a remote access service, wherein the video client device allocates a bandwidth required by video data selected by a user. A client control means for determining and determining a multilink; a bandwidth multilink determination table means for determining a multilink corresponding to a bandwidth required by the video data; and a bandwidth multilink determination table means. Multi-link control means for requesting multi-link in response, wherein the video server calculates a bandwidth to be used between the video client device and the distribution request, and the video server calculates the bandwidth used by the video client device. Video data matching bandwidth Means for selecting and determining a video on demand system. 4. The video-on-demand system according to claim 3, wherein the video server has a plurality of bandwidths corresponding to a bandwidth to be used with the video client device of the distribution request. A video-on-demand system comprising a storage device for storing data in advance. 5. A video-on-demand system comprising a video server and a video client device communicating over a multilink capable of providing a remote access service, wherein the video client device allocates a bandwidth required by video data selected by a user. A client control means for determining and determining a multilink; a bandwidth multilink determination table means for determining a multilink corresponding to a bandwidth required by the video data; and a bandwidth multilink determination table means. Multi-link control means for requesting a multi-link in response, the video server comprising: a multi-link control means for securing a multi-link established by the video client device; Multi Multi-link bandwidth calculation for calculating a bandwidth to be used between a server control means for generating an inquiry signal in response to link information and a video client device of a distribution request when receiving an inquiry signal from the server control means Table means; bandwidth video data determination table means for determining video data matching the bandwidth calculated by the multi-link bandwidth calculation means; and video data corresponding to the determination of the bandwidth video data determination table means. A video data management means for extracting data from a storage device. 6. The video-on-demand system according to claim 5, wherein the video server has a plurality of bandwidths corresponding to a bandwidth to be used with the video client device of the distribution request. A video-on-demand system comprising a storage device for storing data in advance.