KR20020074894A - VOD service via CATV-Network - Google Patents

Abstract

PURPOSE: A device for controlling clustering type VOD(Video On Demand) transmission and reception by using a cable television network is provided to improve the extension of the service by transmitting the compressed digital video data of VOD servers via a wideband CATV network. CONSTITUTION: A device for controlling clustering type VOD transmission and reception by using a cable television network includes a data receiving unit(210) for receiving compressed digital video data in the packet data form transmitted from a VOD server(110), a data extracting unit(220) for developing the packet data received in the data receiving unit to extract the compressed data, a synchronizing unit(230) for synchronizing the compressed data extracted in the data extracting unit, a broadcasting signal synthesizing unit(240) for synthesizing carrier waves oscillated from an oscillator(250) with the synchronized compressed data for producing CATV broadcasting signals of a channel frequency band requested by a user, and a control unit(260) for controlling the operations of the respective units and generating smooth operation instructions, the compressed digital video data of the VOD server is transmitted via a CATV network(300) of wideband.

Description

On-demand control system for clustered video service using cable television network as a communication medium {VOD service via CATV-Network}

The present invention provides a transmission and reception control apparatus for a network device that relays video information between a VOD server and a client in a video service on demand providing a large amount of video information by wire, and compressed digital video in the form of packet data transmitted from a VOD server. Data receiving means for receiving data, data extracting means for extracting compressed data by expanding the packet data received by the data receiving means, synchronization means for synchronizing the compressed data extracted by the data extracting means, and oscillation in the oscillator VOD service transmission and reception comprising a broadcast signal synthesizing means for synthesizing a carrier wave and the synchronized compressed data to generate a CATV broadcast signal of a channel frequency band required by a user, and a control means for controlling the function of each means and performing a smooth work instruction. It relates to a control device.

Video on demand (VOD) is called video-on-demand or video-on-demand, and is used to provide video, movie, education, games, shopping, etc., which are being stored as digital data using a communication network, to users connected through the network. Refers to an interactive system.

The VOD service receives the video selected by the user from the VOD server through the network and is a video providing service that allows the user to freely control the video as if operating the VCR.

Traditionally, over-the-air broadcasting has given broadcasting stations the ability to unilaterally transmit video and audio information to their homes, while the Internet using a network has provided users with the ability to exchange voice and data.

The representative video service among the convergence of air broadcasting and network is VOD service.

This VOD service is characterized by the ability to jump to other scenes provided by video CDs or DVDs (Digital Video Disks), along with functions such as play, pause, stop, rewind, and fast forward, provided by a VCR for a conventional over-the-air broadcast system. It can be provided to viewers as far as other broadcasting services.

1 is a schematic configuration diagram of an existing VOD service system.

Video sources such as movies and animations are digitally encoded and stored in a storage medium such as a hard disk, and the compressed image information is transmitted to the client through the network again at the request of the client coming through the network.

The set-top box of the client receiving the compressed video decodes the compressed video and outputs the compressed video as a video signal.

At this time, the network network mainly used on the VOD service is the Internet using the TCP / IP protocol, the Internet can accommodate a large number of clients in a large area, and there is an advantage in popularization with the expansion of the recent Internet infrastructure.

However, due to the nature of the TCP / IP protocol, there are many limitations in VOD services that require large bandwidths with high throughput and real-time connections.

Because of this, when a large number of users do not secure enough bandwidth, only a low resolution or a simple VOD service with a small screen size becomes possible.

In addition, in order to provide high resolution and real time VOD service, expensive additional equipment is needed because a high bandwidth VOD server capable of inputting and outputting a large bandwidth network and a large amount of data at high speed is required.

The Internet, which is currently used for VOD service, has the advantage of accommodating a large number of clients at the same time, but cannot provide a TV-level VOD service due to bandwidth limitation.

Moreover, in order to overcome this problem, it is necessary to have a high-performance VOD server, which is also expensive, which is an obstacle to the expansion of VOD services.

Therefore, it has been desired to develop a VOD service that is affordable and accommodates a large number of clients.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and includes data receiving means for receiving compressed digital video data in the form of packet data transmitted from a VOD server, and extracting compressed data by developing packet data received by the data receiving means. A broadcast signal for synthesizing the compressed data extracted by the data extraction means, the synchronization data for synchronizing the compressed data extracted by the data extraction means, the carrier wave oscillated by the oscillator and the synchronized compressed data to create a CATV broadcast signal of a channel frequency band required by the user Synthesis means, and control means for controlling the function of each means and to perform a smooth work instruction, it is possible to greatly improve the scalability of the service by transmitting the compressed digital video data of the VOD server to the client over a broadband CATV network VOD service transmission and reception control device There is a purpose.

Another object of the present invention is to modify the protocol data by including the allocation information of the channel frequency band requested by the client in the packet data provided by the low-cost clustering method server, thereby enabling the multi-channel transmission to increase the bandwidth of the VOD service To provide a VOD service transmission and reception control device that can be.

1 is a schematic configuration diagram of an existing VOD service system.

2 is a block diagram of a general clustering server.

3 is a block diagram of a VOD service transmission and reception control apparatus according to a specific embodiment of the present invention.

4A to 4E are conceptual views illustrating a method of transmitting a compressed video packet according to an embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

100: clustering server 110: VOD server

200: interface module 210: data receiving means

220: data extraction means 230: synchronization means

240: broadcast signal synthesizing means 300: CATV network

The present invention provides a transmission and reception control apparatus of a network device for relaying video information between a VOD server and a client in a video on demand service providing a large amount of video information by wire, and receives compressed digital video data in the form of packet data transmitted from the VOD server. Data extracting means for extracting compressed data by expanding the packet data received by the data receiving means, synchronization means for synchronizing the compressed data extracted by the data extracting means, carriers oscillated by the oscillator and the And a broadcasting signal synthesizing means for synthesizing the synchronous compressed data to create a CATV broadcasting signal of a channel frequency band required by a user, and a control means for controlling the function of each means and performing smooth work instructions. to provide.

The VOD server applied in the present invention is a server of a clustering method.

It is designed to reduce the load on the VOD server in the way data is managed, and is designed to perform fast tasks. It connects multiple servers in parallel and performs common tasks for specific tasks, acting as a single server. It is a technique to operate.

In other words, it divides a job into pieces and distributes them to different servers for execution.

This clustering method is mainly used where complex calculations are required, because it is more efficient to compute with multiple server CPUs than with one server CPU.

Typical clustering servers include availability clustering servers, scalable clustering servers, and manageability clustering servers.

Availability clustering refers to the way in which additional systems are configured to minimize server down-time. Scalability clustering shares system resources such as CPU, memory, and IO among servers to ensure system performance and It is a configuration method that improves processing power.

In addition, manageability clustering is a configuration method for managing servers as one server by establishing a single interface between the same servers or heterogeneous servers.

However, not all clustering configurations need to include all three clustering techniques mentioned above. In general, most commercial clustering products are composed of a combination of two of the three clustering techniques.

2 is a block diagram of a general clustering server.

The components that make up a clustering server consist of a server system, an Ethernet card, a hub, and Parallel Virtual Machine (PVM) software.

Each individual server system is connected to each other by an Ethernet card and a hub, where the PVM on each server makes each server act as a single virtual server.

Each individual server belonging to a clustering server has a different role depending on the application to which the clustering server is applied.

Examples include web servers that handle client requests, streaming servers that provide VOD to clients, and load balancing servers that balance the load of each streaming server.

The clustering server is superior to the general server in the simultaneous processing capacity and the maximum processing capacity, and in the case of the server having the same processing capacity, the clustering server is much cheaper than the general server. This is because normal servers require expensive components and software to achieve high performance, while clustering servers connect inexpensive, low-performance servers in parallel.

CATV (cable TV) network is proposed as a broadband communication medium proposed in the present invention, which is known as a multi-channel broadcasting that transmits video and audio to a client through a wired network.

Initially, the service was provided to solve the astigmatism area of terrestrial broadcasting, but since then, thanks to the characteristics of multi-channel, specialized multi-media has been advanced unlike the terrestrial broadcasting.

CATV system is mainly composed of center part, transmission part and terminal part.

The center part mainly refers to the CATV base station equipment, the transmission path part refers to the CATV network, and the terminal part refers to the client's set-top box.

The CATV network is mainly composed of a tree network, which is the most basic CATV network structure, and is effective in distributing the same signal to multiple clients.

CATV network developed for broadcasting uses channel allocation method according to frequency band and can secure about 100 analog broadcasting channels of 6 MHz band in normal CATV network.

In a CATV network in a tree network, clients see the same broadcast on the same channel.

At present, analog CATV networks are mainstream, but the digitalization of CATV networks is being promoted mainly in the United States.

Since the CATV network does not adopt the packet transmission method, it cannot accommodate many clients at the same time as the Internet, but it has a bandwidth suitable for VOD requiring real time, and the high bandwidth of the CATV ensures a high quality VOD service. .

Hereinafter, with reference to the accompanying drawings with respect to the configuration and operation of the embodiment according to the present invention.

3 is a block diagram of a VOD service transmission and reception control apparatus according to a specific embodiment of the present invention.

Each individual server 110 constituting the clustering server 100 packetizes and transmits compressed digital video data stored in each hard disk 120 at the request of a user, and processes many user requests. In order to do so, several individual servers 110 operate in parallel and independently.

At the output end of the clustering server 100, there is a hub 140 connected to the transmitting end Ethernet card 130 of the VOD servers 110, and the image information carved into each VOD server 110 is connected to one connection path. Send it together.

In this case, the transmitted data are divided and transmitted in packet units.

In contrast, the data of the CATV network 300 is in the form of a continuous stream, and the data is divided into frequency bands.

Accordingly, the present invention uses a method of transmitting specific packet data of the VOD server 110 to a specific channel of the CATV network 300 in order to connect the clustering server 100 to the CATV network 300.

Performing the above-described role and controlling the transmission and reception of data on the network is referred to as an Ethernet-to-CATV network switching interface module 200 in the present invention.

The interface module 200 expands the packet data received by the data receiving means 210 and the packet data received by the data receiving means 210 to receive compressed digital video data in the form of packets transmitted from the individual VOD server 110. The user extracts the data extraction means 220, the synchronization means 230 for synchronizing the compressed data extracted by the data extraction means 220, and the compressed data synchronized with the carrier wave oscillated by the oscillator 250. Broadcast signal synthesizing means 240 for producing CATV broadcast signals of a required channel frequency band, and control means 260 for controlling the function of each means and performing a smooth work instruction.

Looking at the operation of the interface module 200, which is a VOD service transmission and reception control device having such a configuration through a specific embodiment as follows.

The VOD server 110 forms the compressed data required by the client in the form of a packet and transmits the compressed data to the interface module 200 through the sender Ethernet 130.

The transmitted packet data is received via the data receiving means 210 of the interface module 200, that is, the receiving side Ethernet, and the received packet data is expanded by the data extracting means 220, that is, a format converter to compress the compressed data. Extract

In this case, the compressed data includes channel assignment information, which is information on which channel of the CATV, should be allocated in the form of a protocol. It will be assigned to the channel.

4A to 4E are conceptual views illustrating a method of transmitting a compressed video packet according to an embodiment of the present invention.

As shown in FIGS. 4A to 4E, the transmitted compressed data includes channel assignment information such as channel 1, channel 3, channel 1, and channel 2, and corresponds to each channel assignment information through the data extraction unit 220. Compressed data is allocated to the channel.

The allocated compressed data needs to be synchronized with a corresponding channel frequency band required, and this role is performed by the synchronization means 230, that is, a time delay & synchronizer.

Synchronized compressed data is delivered to a carrier mixer 240, that is, a carrier wave mixer.

The carrier mixer 240 synthesizes the compressed data and the carrier wave of the frequency band required by the channel assignment information by oscillation in the oscillator 250 to generate a digital CATV broadcast signal.

The broadcast signal is transmitted to the client through the CATV network 300, and the client decodes the broadcast signal through the set-top box 310 to watch.

The present invention described above is not limited to the above-described embodiment and the accompanying drawings, and various substitutions, conversions, and modifications are possible within the scope without departing from the technical spirit of the present invention. It will be evident to those who have knowledge.

As can be seen from the above description, the present invention has an advantage of greatly improving the scalability of a service by transmitting compressed digital video data of a VOD server to a broadband CATV network.

In addition, the present invention transforms the channel frequency allocation information requested by the client into a packet-type compressed digital video data provided by a low-cost clustering server, thereby enabling multi-channel transmission to widen the VOD service. We can plan.

Claims (3)

In the on-demand video service that provides a large amount of video information by wire, in the transmission and reception control apparatus of the network device for relaying the video information between the VOD server and the client, Data receiving means 210 for receiving compressed digital video data in the form of packet data transmitted from the VOD server 110, Data extracting means 220 for extracting compressed data by expanding the packet data received by the data receiving means 210; Synchronization means 230 for synchronization of the compressed data extracted by the data extraction means 220, A broadcast signal synthesizing means 240 for synthesizing the carrier wave oscillated by the oscillator 250 and the synchronized compressed data to generate a CATV broadcast signal of a channel frequency band required by a user; It is provided with a control means 250 for controlling the function of each means and performing a smooth work instruction, VOD service transmission and reception control device, characterized in that to greatly improve the scalability of the service by transmitting the compressed digital video data of the VOD server 110 to the broadband CATV network (300). The VOD service of claim 1, wherein the data extracting unit 220 allocates the compressed digital video data to a channel frequency band requested by a client by recognizing channel allocation information included in a protocol form in packet data. Transmission and reception control. The apparatus of claim 1 or 2, wherein the packet data is transmitted from a clustering server (100) in which a plurality of VOD servers (110) are connected in parallel to perform one task.