KR20020035571A - Vod from a server or a user to another user - Google Patents

Abstract

Systems and methods are disclosed for transmitting data to multiple end users 5-12 using distributed storage systems connected through a communications network. The end user apparatus for audio and video reproduction and recording includes a storage unit such as a magnetic disk. Such a storage unit can store data such as digital video content, ie movie or audio content, ie songs. The storage unit may be configured to store a portion or fragment of digital video or audio content, wherein the storage location, playback, and recording of the digital video and audio content of each storage unit is coordinated and managed by the central facility 1. And controlled. Content for playback of video or audio content, or portions thereof, may be present in one or more physically separate storage devices or in a central storage device.

Description

VOD FROM A SERVER OR A USER TO ANOTHER USER}

Since the advent of VCRs, more and more people want to have a movie-on-demand system to reduce the need for viewers to go to a video rental store. "Video On Demand" ("VOD") systems allow viewers to choose a movie or video program at their discretion and watch the video content immediately, at any time, such as hours or even days later. It's electronic, so you don't have to buy physical media like video tapes or video discs, and you don't have to rent them at a video rental store to return them.

Cable companies implement several types of video transmission systems for their cable customers. However, due to storage space and bandwidth limitations, the choice of movies is extremely limited, and viewers can watch movies only at the time specified by the cable company. The person who wants to see a classic movie loan on the evening of the evening is unhappy. As a result, few systems have a degree of flexibility suitable for a broad audience, so the system provided by the cable company is not a true VOD system.

Implementing an on-demand video system for a large number of viewers is difficult and expensive. There is a need for a multimedia server capable of simultaneously transmitting a variety of continuous audio and video streams to hundreds or thousands of different end consumers. Ideally, consumers can choose their content from a library of hundreds of movies or songs. However, a typical hard disk drive can hold several full-length movies, which means that a multimedia server must have more than 50 disk drives. Figure 1A shows a conventional cable broadcast system for this "on-demand video" supply.

Another difficulty when implementing large shared multimedia servers is the need to process and transmit various streams of digital multimedia content. Compressed television signals at standard resolution are transmitted at an average data rate of about 4 megabits per second. If a multimedia server had to send hundreds of other programs simultaneously, the average overall bandwidth required would be about 400 megabits per second. This large amount of data must also be sent to a hundred viewers without any detectable discontinuity, otherwise the viewing experience deteriorates. Networks with high quality of service (QoS) and maintaining this high data rate from a central server to many users are very expensive and unrealistic for anyone to make.

With the advent of communications over the Internet using cable modems, it has been proposed that cable modems by cable companies enable the provision of video on demand. Cable modems connected to the Internet needed to succeed what cable companies did not succeed: on-demand video systems using the Internet.

1B illustrates how video on demand has a cable modem in a metropolitan area and is provided to a cable TV broadcast system. In this system, the analog TV signal is received by the satellite dish 1. Analog TV signals are combined with video-on-demand and digital communication signals from the Internet through signal combiners.

In FIG. 1B, the video on demand signal is digital, which may be analog. Digital content, such as world wide web pages on the Internet public network, is connected to the system via a router 3. The router 3 is used for transferring packet data from one network to another network, such as between the Internet network and the Ethernet network switch 4, for example. The Ethernet network switch 4 exchanges data with the Internet router 3, the fiber return channel decoder 5, the file server 6, the multimedia server 8, and the modulator 9. The fiber return channel decoder 5 returns the signal returned from the customer premises equipment (“CPE”) through the optical fiber 11 in digital form, which is transmitted to the Internet. File servers can be used to maintain world wide web pages or to cache Internet information. The multimedia server controls the content database 7 and can read several movies or songs simultaneously. The content database can hold all digitized movies or songs. Digital data transmitted from the multimedia server or the Ethernet switch to the end user may pass through the digital analog modulator 9 before combining with the analog TV signal from the satellite dish 1.

Referring again to FIG. 1B, the signal passing between the optical fiber 11 and the coaxial cable 13 may be transmitted by the coaxial-to-fiber converter 12. While the digital signal is converted to digital by the cable modem 14 for use by the PC 15, the analog TV signal is converted into frequency through the set top box 16 for transmission to the TV set 17. Can be. While different homes have different CPEs 19, the customer premises device 18: CPE in a single home has a set of devices, and each customer views different video, audio, and data content. do.

It is not uncommon for hundreds and thousands of customers to be served by one provider device. This means that the multimedia server must potentially provide different customers with different movie or music data streams at the same time. This is practically impossible if there are thousands of customers and only one multimedia server. One solution could be to have a variety of multimedia servers, each with a subset of customers, but it doubles the cost of serving all customers. Another problem is that large amounts of multimedia data must be moved from a centralized multimedia server or group of servers. Each customer can watch different points in time (eg, at the beginning, middle, and end of the video) of different videos from the multimedia server, and each video is treated as a distributed channel. The bandwidth of hundreds or thousands of distributed channels, in addition to regular broadcast channels, is higher than the current transmission path can handle today.

Thus, it is desirable to have an on-demand data transmission system that allows multiple recipients to receive the same or different content at any time they choose.

It is also desirable to have an on-demand data transmission system or the like that does not waste the bandwidth or transmission base of the server.

The present invention claims priority to provisional application No. 60 / 146,893, entitled "Method and Apparatus for Data Delivery Using Distributed Storage System", filed August 2, 1999.

The present invention relates to a data communication network, and more particularly, to a method and apparatus for transmitting data using a storage unit that has been preponded over a network such as the Internet.

1A illustrates a conventional video-on-demand system on a cable broadcast system;

1B illustrates an exemplary video-on-demand system installed in an end user installed in a cable modem;

2A illustrates an embodiment of a method in which a single multimedia server simultaneously delivers AV content to hundreds of users.

2B illustrates an embodiment of how three cache memories may be inserted between a multimedia server and a customer;

3A is a simplified block diagram of an End Node Equipment at a user's site;

3B is a simplified block diagram of a conventional VOD system with end node devices between a central server and a user;

4A is a simplified block diagram of an end node device with a cable modem for use with a TV in accordance with the present invention;

4B is a simplified block diagram of an end node device with a cable modem for use with a PC in accordance with the present invention;

4C is a simplified block diagram of a distributed server system of the present invention;

5A and 5B illustrate the simultaneous transmission of content from multiple end nodes with reduced playback start time;

6 is a simplified block diagram of a VOD system based on a DSL network;

7 is a flowchart illustrating a process of distributing content to an end node unit;

8A and 8B illustrate another embodiment of a VOD system in which content is transmitted from a combination of end node and content server.

Systems and methods for transmitting data to various end users using a storage system connected through a data communication network are disclosed, and end user devices for audio / video playback or recording include storage units such as magnetic disks. Each storage unit can store digital video content, ie data such as movies or digital audio content, ie data such as songs. The storage unit is configured to store a portion or fragment of digital video or audio content, and the storage location, playback and recording of the digital video or audio content of each storage unit is coordinated, managed and controlled by the central facility. . Content for playback of video or audio content, or portions thereof, may reside in one or more physically distributed storage units, or may reside in a central storage unit.

Content can also be read and transmitted simultaneously from one or more physically distributed storage units to one or more other physically distributed sites, and the entire content, such as a movie, can be distributed in the same or non-identical pieces, The pieces may be stored in multiple physically distributed storage units. The allocation of the storage location of the piece, the transmission priority and the destination of the piece are centrally managed and controlled. In anticipation of the need to transmit the same content to other customers in the near future, the content may be simultaneously delivered to storage units that do not want the content to be displayed. This allows the allocation of dynamic resources at any time, peak or non-peak in the prediction of excessive download of some program, such as new work.

In addition, the data communication network connected between the storage units can be wired or wireless. Although the Internet uses cable modems, other forms of network connection may be used.

As is known to those skilled in the art, what is disclosed in the following description is a "set top box" locally or remotely connected to a disk drive or file server, and a "set top box" is referred to as a file server in another "set top box". Play a role. As such, the entire set top box is bulky and is a storage facility distributed to each member set top box. Also disclosed is a personal computer comprising a disk drive that can act as another file server or set-top box, and the file can be distributed in any size for distributed storage or transmission on multiple computers or set-top boxes. .

A method and apparatus for transferring data using a distributed storage system is disclosed. In the following description, the invention uses the terms server, switch, router, database, end node, network, and the Internet, which terms are typically used in conversations among those skilled in the art. Further, those skilled in the art will understand that the term “data” may refer to audio or video content, multimedia content, or simple binary bits transmitted over a communication network.

As mentioned above, one way to reduce the bandwidth requirement of a multimedia server is to have a primary network transmission path to cache the first transmission of content. In addition, requests of the same content from other end users may be serviced from the caching storage unit.

2A illustrates an embodiment of a method in which a single multimedia server may be requested to simultaneously deliver AV content to hundreds of users. Because some content may be more popular than others, many customers may be watching the same AV content. For example, a newly released film is much more popular than a few years old. However, it is desirable to allow a customer to start a movie at a time desired by the customer rather than on a fixed schedule, which occurs in the way that the cable company provides the video program. This means that even if some videos are being watched by more than one customer, the data must be transmitted redundantly because the movie must be watched at different points in time.

Figure 2B illustrates how a cache memory is inserted between the multimedia server and the customer to facilitate transfer orders. Each cache memory is supplied to a smaller group of total customers. If the AV content is not previously stored in the group's cache memory, it will be provided by the central multimedia server. The AV content will be sent to the customer and also temporarily stored in the group cache memory. If other customers in the group request the same AV, the AV content continues to be stored in the cache memory, and the cache memory can easily provide the content. This reduces the load on the central multimedia server and reduces the bandwidth used by the user. However, there is a clear problem with this approach. If the cache memory is too small, only a fraction of the AV content can be stored, so many content requests over cache. This reduces the bandwidth and the effect of reducing the load on the central multimedia server. However, increasing the cache memory increases the cost.

As described above, the present invention provides a solution to the problem of the conventional way of distributing data, such as digital multimedia, by having a system of storage units at the end node, which serves as the primary storage of multimedia content. . Although centralized multimedia servers may be used to increase the delivery of multimedia content, most of the multimedia data requests from the end nodes will be serviced from each storage unit at the other end node.

Such distributed server systems, when used to distribute time-critical multimedia content, can solve the inherent problems of current centralized server systems. As will be described below, FIGS. 3A and 3B show a conventional system using a centralized server, while FIGS. 4A, 4B and 4C show a distributed server system according to the present invention.

3A is a simplified block diagram of a conventional end node device that may be installed at a user's site. This is usually a set top box ("STB") connected to a TV. STBs typically have cable modems, digital video and audio decompression circuits. As shown in FIG. 3B, the multimedia server 1 controls the content database 13 that stores all the multimedia content. The network switch 2 controls the transfer of data between the server, the network switch 3 and the network switch 4. The network switch 3 transmits data from the network switch 2 to the user end nodes 5 to 8, and the network switch 4 transmits data from the network switch 2 to the user end nodes 9 to 12. do. In this embodiment, the end nodes 5, 8, 9, 11 receive multimedia data from the centralized server 1. The server 1 and the switch 2 can be spaced long distances, which requires expensive high bandwidth connections.

The content data streams (A, B) at the end nodes (5, 8) are routed from switch (2) to switch (3), and the content data streams (C, D) at end nodes (9, 11). Is routed from switch 2 to switch 4. The switch 3 routes the data received by itself to the end nodes 5 and 8, and the switch unit 4 routes the data received by the switch to the end nodes 9 and 11. In this system, all four data streams A through D must come from the content base 13 via the server 1, the switch 2 and the switches 3, 4. Due to the time-centric nature of the multimedia data, all components and network interconnections between the content database 13 and the end user must be high speed, low latency. The system in Figures 3A and 3B will obviously have its limitations, especially when a large number of end nodes request data at the same time.

4A illustrates a customer oriented end node device for watching digital video on a TV. The STB includes cable modems, storage units such as disk storage, and digital video and audio demodulation circuits. Of course there is a TV for displaying the program from the cable. 4B shows a PC-oriented device for watching digital video using a cable modem or DSL modem for acquiring data, for example with a PC having a storage unit such as a disk storage device.

In a PC-based end node device as shown in FIG. 4B, the operation is recorded in Sun's Java Media Framework (JMF) that supports multiple Internet protocols called Real Time Protocol (RTP) and Real Time Streaming Protocol (RTSP). It can be controlled by software. These software programs are generally considered "off-the-shelf" by those skilled in the art and their performance is also well known to those skilled in the art. Java programs can be written using the JMF library to facilitate the transfer of data, are programmed to support their sending end nodes, and other programs are programmed to support their receiving end nodes. Those skilled in the art will appreciate that software may be written such that the PC controls the corresponding task.

Currently, in demonstration and prototype units, the person running the receiving PC installs the Sun Java Development Kit (JDK) software, which can be downloaded and used at http://www.javasoft.com, for example, a service company. Receiver software can be obtained via email from.

In the product version of the software that runs the end node device, the end user can visit the company's Web site and install the transmit and receive software online. Autostart software routines can be installed in the PC's startup directory so that the transceiver software can be started when the PC is turned on or restarted. Because many people can share a single PC, the installer can include personal information in a specific file (which is commonly known as a "cookie" file) to identify the PC and the current PC user.

The method by which the end node device can be started at startup is described below. It should be noted that those skilled in the art can easily devise their own starting route and protocol, and develop a vehicle body distribution system according to the present invention. The following description is for illustrative purposes only. At initiation, a transmission / reception program at the end node device, for example a PC, sends a message to the control software at the provider's web site, not only sending identification information, but also notifying that it is ready to send and receive on request. Upon receiving this notification, the service provider's control software knows that a particular PC is available.

Once the service provider's server knows that the end unit is useful,

Add new content to the end unit receiving instructions and data,

Remove old content from the end unit receiving the command,

Send the current content to the end unit receiving the command,

Commands and data can be sent to check the current content to tamper with or perform other maintenance tasks.

In one embodiment, the control software may need to know when a particular PC is no longer useful. In this scenario, when the user turns off the PC, when the PC crashes, when the user loses power, or when the cable network simply stops working, that is, suddenly, the control software on the PC identifies the power cut. You can do this and send a message to the server saying it is no longer useful.

If a crash or loss of functionality occurs on the PC without notification to the provider's server, it is desirable that the distribution system be recovered so as not to compromise the viewing user's experience. Once a series of transmissions have been established, that is, the viewer of another end node unit wants to watch the movie, the server can immediately check the statistics for all the end units that the server finds useful. If the end node unit fails to respond, the server may mark the end node as not useful and switch to another end node unit. The initial transfer list is always launched with end node units that have been approved as useful.

Once the movie has started, the receiving PC expects the data from each transmitting PC until a certain time. If a collision occurs and one PC does not transmit data by the scheduled time, the receiving PC can notify the provider's server. The server can replace the other end unit immediately by providing the rest of the transmission list to the replacing end unit and notifying the receiving unit of the Internet address of the replacing unit. To facilitate delivery, the provider may have a backup server that provides delayed content to the receiving end unit for a few seconds until the opposing end unit speeds up.

See Figure 4C. As shown in FIG. 4C, the content database 13 is set up to relieve some of its obligations to the entire distribution system. All multimedia data is distributed between the user of each user end node (not shown) and the storage unit of the node. Not all end user nodes need to have a local storage unit, and as end user nodes have a storage unit and participate in the distribution, the performance of the system is improved. The multimedia server 1 acts as a centralized administrator to keep track of how multimedia content is distributed among end user nodes. The network connection between the server 1 and the switch 2 requires less bandwidth because only the commands and status information need to be transmitted without the multimedia data, and the storage device is distributed among the end nodes. As will be appreciated by those skilled in the art, the storage unit at each end node may be a hard disk drive, and some storage devices may store, transmit, and play the multimedia content. As the price of storage devices decreases due to advances in technology, this type of distributed storage becomes more active and profitable in price.

In the system shown in FIG. 4C, the end node 5 needs multimedia content A, the end node 8 needs multimedia content B, and the end node 9 has multimedia content ( C) and the end node 11 needs multimedia content D, while the storage unit of the end node 6 contains the multimedia content A and the storage of the end node 9. The unit comprises multimedia content B, the storage unit of end node 10 comprises multimedia content C and D, and the storage unit of end node 12 comprises multimedia content B.

As shown in FIG. 4C, a distributed storage system may be used by the multimedia server 1 to transfer various content from the content database 13 or from where the content may be available to the end node. The distribution may be based on the expected popularity of any content and whether the end nodes are in the same switch network. For example, if 200 end nodes share the same adjacent switching network, for example, a newly released movie in the same neighborhood needs to exist at 10 end nodes for stable transmission. If the delay is not severe, it may come from an end node in another unequal switching network. The other 190 end nodes may exist with different content in fragments, in whole, or in a combined form. As the requirements change, this is only an initial step, since the location and distribution can be reliably changed to reflect usage where the location can be tracked using the usual tools for statistical analysis.

In addition, initiation or accompanying location management can be done during non-peak time, as no interference from the customer is required. Thus, while most customers sleep at 3 am, the storage units at their end nodes can receive many commands from the central server, preferably send content and update the central server. As new content emerges, new content will cause old content to be deleted or replaced gradually or all at once. The distributed storage system is dynamic, allowing it to consistently and consistently satisfy customers' permanently changing needs.

Since the storage of this content is distributed, the end node 6 acts as a server at the end node 5. If the network connection between the two nodes is a shared medium, it will be possible for the end node 6 to send content (A) data directly to the end node 5, otherwise, switch the content (A) ( 3) to end node 5, and to node 5 using conventional internet or data network addressing techniques. The multimedia server 1 receives a request from the end node 5, checks the availability of the requested content, for example determines the most convenient transmission method from the end node 6, and ends the content A. It is desirable to be able to act as a "traffic controller" to instruct the end node 6 to transmit to the node 5.

Referring again to FIG. 4C, when the end node 6 responds to requesting content A from the end node 5, the viewer at the end node 6 requests to play this content A. FIG. . In such a situation, data can be read into a memory of a processor such as a PC or STB, for example, in a storage unit such as a hard drive. The data is then transferred from the processor's memory to the cable or DSL network. If the same data is sent very close to the local broadcast, the data can be cached in memory and sent to the local display. If not cached in memory, data can be read back from the hard drive. As will be appreciated by those skilled in the art, STBs as well as current PC systems with high speed processors and communication capabilities can simultaneously handle two sets of read requests.

An alternative to a multimedia server that acts as a centralized traffic controller is to have each end node broadcast its request to another end node. This end node with the requested content will monitor the delivery status to determine if it is the best source for the requested content. If so, it will send the requested content to the requestor in response. If there are multiple responses to the request, the requested end node will determine the priority for reception and identify the source end node of priority for transmission. If the transmission is blocked, the requesting node can go to the next source end node in priority order. The second source end node may send to pick up the location where the first source end node left.

Similarly, the end node 9 acts as a server for the end node 8 to transmit content B, and at the same time receives the content C from the end node 10. The end node 10 may serve as a server by storing the contents C and D and transmitting the contents C to the end nodes 9 and simultaneously transmitting the contents D to the end nodes 11. .

End nodes should not be servers on their own. They play a role over time or simultaneously with other end nodes to complete the transfer. End node 8 may receive content B from both end node 9 and end node 12. This reduces the delivery time of the content B, which may be desirable, especially when the upload speed (from the end node to the switch) is lower than the download (switch to the end node) speed. This is common in cable modem and asymmetric digital subscriber line (ADSL) network technologies. It is more useful at the point where the playback of content begins before the entire content is downloaded to the end end. For example, based on the speed of the initial portion of the download from the end node 9 to the end node 8, playback of the content B may occur before the download from the end node 9 reaches the end of the content. If expected to be completed, playback of content B may begin. However, once playback starts, the download speed may decrease due to unexpected network congestion from switch 4 to switch 3, or the upload speed may decrease due to unexpected congestion from switch 9 to switch 8. In that case, the unviewed portion of content B may be sent from end node 12 to end node 8.

As an example, assume that end node 8 has received 25% of the content B from end node 9. Based on the playback speed of the content as well as the 25% download speed of the content, the end node 9 starts playback. In this example, the playback speed is the same as the download speed. At the 30% receiving point, the download speed is slowed by two. If the download speed is not increased, playback of content B will stop at 90% of the movie or song. That is, at 35%, the end node 12 will be instructed to immediately begin delivering the last 20% of the content B, and the end node 9 will immediately continue to deliver the content at 35% and stop at 80%. You will be commanded to do so. This method may be useful when the upload transfer rate or switch to switch transfer rate is lower than the download transfer rate.

The method of transmitting from multiple nodes simultaneously may be used to reduce playback start time in a network where the data playback speed and download speed are higher than the data upload speed. For example, suppose the playback speed is 2 megabits per second, the download speed is up to 3 megabits per second, and the upload speed on a single-ended node is 1 megabit per second. In the network shown in FIG. 5A, the end node 5 wants to play the content A stored in different fragments at the end nodes 6-15. The information about the location of the fragments at different nodes is preferably able to be stored in the multimedia server 1. The upload and download performance of different nodes can be stored in the multimedia server 1 or a test transfer can be made to measure the upload and download speed.

Referring to FIG. 5A, an end node 5 connects with the multimedia server 1, which integrates the transmission of a fragment of the end node 5 from another end node. In the first step, the end nodes 6, 7 and 8 send their stored fragments to the end node 5, where the end node 5 has each fragment from each transmitting end node being only 1 megabit per second. Even though it can be uploaded at, it will receive three fragments simultaneously at 3 megabits per second. Since the fragment containing 0-5% of the content from the end node 6 is being transmitted at half the playback speed, the end node 5 can start playing the content until the first half of the fragment is received. none. If you start playback sooner, the data stops before the fragment reaches full, causing playback to stop.

Sometimes the Internet address of an end node is not fixed, but sometimes it can't change. The program of each end node can be used to inform the controlling multimedia server 1 when the Internet address changes.

When the fragments from the end nodes 6, 7, 8 are sent to the end node 5, as shown in Fig. 5B, the multimedia server 1 includes the end nodes 9, 10 containing the necessary fragments. We can arrange for 15-30% of subsequent transmissions from other end nodes, such as. While the end nodes 9, 10, 11 are transmitting data to the end node 5, the end nodes 6, 7, 8 can, if necessary, transmit data to other end nodes.

Although one content database and one multimedia server are shown in FIG. 5B for explanation. It should be noted that the entire distribution system according to the present invention can realize multiple content databases with multiple multimedia servers scattered throughout the country, state, and county. Delivery content to one end unit may come from several different end units, but may come from one or more content servers. This "collective" effect can offload the load on one particular server or database and provide an efficient design for performing content transfers from the database and servers in close end units.

5B, when the end node 5 completes the viewing content A, the storage unit will have a completed copy of all fragments of the content A. FIG. If content A is expected to be popular at another end node, i.e. a new movie, the entire content remains stored at the end node 5, so that it can be transferred to another end node or only partially maintained. . Which portion remains in this end node is determined based on the situation of storage or distribution, content A in another end node. For example, the storage situation may be a situation where the front 30% fragment of content A is needed, since other end nodes may contain enough other fragments. If the content A is not expected to be watched for the time being, it can be deleted immediately, or the first content is designated to be deleted when other content needs to be stored in the storage unit of the end node 5.

Referring to FIG. 7, a process of distributing content to an end node unit according to an instruction from a server is illustrated. As shown in FIG. 7, the end user unit EUU1 informs the central server 1 that it is online, activated and ready for example after EUU1 is installed in the end unit's home. In this notification, the central server sends the data block N to the end user's home. When EUU2 requests data block N from the central server, the central server will notify EUU2 that data block N will be sent from EUU1. In this way, the central server may instruct EUU1 to transmit the requested data to EUU2. At this time, the Internet forwarding address is that of EUU1, and the Internet receiving address is that of EUU2. Upon receiving the requested data block, EUU2 notifies the central server that the transfer is complete. 8A and 8B, another embodiment of a VOD system in accordance with the present invention is shown. It should be noted that in the system shown in FIGS. 5A, 5B, multiple end nodes have been transmitted by a single multimedia server 1. 8A and 8B show an alternative or refinement of the present system, where the functionality of the multimedia server is distributed in separate parts, and the load is essentially reduced, so that the content is transmitted in combination with the end node and the multimedia content server. . Content delivery is performed by distributed content servers as well as other end nodes.

In the system shown in Figures 8A and 8B, the end nodes (C, D) can be personal computers or other devices typically present in the home. The control server A can be an Internet server computer that performs control and cooperative roles. Examples of this Internet server computer include a Compaq Proliant server using the Microsoft NT operating system and its equivalent. Web server (B) is an Internet server computer, for example, Sun Microsystem's Enterprise server or equivalent, which uses the Sun Solaris operating system to deliver web pages to end nodes, but may or may not maintain multimedia content. have. The multimedia content servers E and F may be Internet server computers that retain multimedia content. Although the functions are distributed for this embodiment, it is possible for an Internet server computer to control and combine the control, web serving and multimedia content serving functions in any combination, which is known to those skilled in the art.

8A and 8B show another embodiment of the VOD system according to the present invention, in which the multimedia data is transmitted from the combination of the multimedia content server and the end node to the end node. This embodiment makes it possible to build a system that only transfers multimedia data from a multimedia content server to an end node or multiple end nodes.

As described above in this embodiment, multimedia content such as movie files may be fragmented into smaller files, and the smaller files may be distributed for storage by end nodes and / or other servers. In this embodiment, the content fragments may be distributed to end nodes (C: step 3), end nodes (D: step 4), multimedia content servers (E: step 3), and multimedia content servers (F: step 3). have. In addition, the present invention makes it possible to distribute copies of file fragments to additional end nodes or servers such that each file fragment may exist on one or more end nodes or servers. Such redundancy may enable replacing an end node or server with another, which is useful if the end node or server is slow when sending data. Data may reside at these end nodes and servers and may be transmitted if necessary.

In addition, as described above, the viewing end node may include some software that can reintegrate the file fragments in the order of the original file. Finally, the end node or internet server holding the movie file fragment may include some software that accepts instructions from the control server and enables the file fragment to be sent to the end node or internet server.

In FIG. 8A, step 1 occurs when the user at the end node D wants to watch a movie. The user sends a request to the web server B for movie data. In step (2), the web server (B) sends a request to the control server (A). The control server A determines which end node or the Internet server has the desired movie file fragment. In step (3) the control server A transmits a command to the end node C, the multimedia content server E, and the multimedia content server F to transmit the desired movie file to the end node D. In step 4, as shown in FIG. 8B, the end node C, the multimedia content server E, and the multimedia content server F transmit together the movie file fragment to the end node D. FIG. It will be appreciated that if each fragment is coded to provide the same identifier for other fragments of the same title, reintegration, or reassembly, of the various fragments may be done by the viewing end node. This reintegration or reassembly may allow the viewing end node to obtain a "script" of the fragment to be sent from the server in response to the initial request of the viewing end node. This "script" is like the instructions in the bicycle assembly instructions, which facilitates reintegration and reassembly of the fragments.

It will be appreciated that once a movie title or data file is fragmented each fragment should have the same code identifying its position in the entire movie. Preferably, a standard way of location coding of movie and data files is made, and similarly, Internet files are packetized and distributed over the Internet for transmission and assembly only at end destinations.

Although not shown, those skilled in the art will understand that the web server B can serve as a multimedia content server.

Each piece of data stored by the EUU may be encrypted using a different encryption key for security purposes. For example, if the EUU stores five fragments from five programs, that is, one fragment from one program, each fragment can have its own encryption key. By having an encrypted fragment or program, the user can block unauthorized access to the EUU. As will be appreciated by those skilled in the art, the storage device within each EUU is preferably transparent to the user, whether the EUU has a full length movie or a collection of fragments of various content.

In accordance with the foregoing, the present invention is directed to fragmenting and distributing content among multiple networked storage nodes, even if the upload transmission rate of content from a single end node is slower than the playback and download rate of the playback end node. Provides continuous playback of content with minimal time. The present invention also allows for multiple end nodes to watch the same content with a small delay between each viewing, where the delay is set by the time duration of the fragment. The present invention can be used by bidirectional transmission of data. For example, the network may use the DSL (digital subscriber line) technology shown in FIG. 6 instead of or in connection with the cable TV technology shown in FIG.

Although the present invention for transmitting data has been described for implementing an on-demand video system with distributed storage, those skilled in the art will understand that the present invention may also implement a "on-demand data" system. In such a system, the storage unit of each end user's site will store data for access by another user or himself. For example, assuming a mechanism exists to transfer and assemble data through a central server to control, track, and manage storage, the stored data can be part or fragment of different kinds of data, and these It is assembled with other parts anywhere to create a complete piece. In addition, the person managing such a network to implement data secrecy and encryption needs to coordinate to prevent uninvited access of stored data by end users.

As will be apparent to those skilled in the art, the present invention can be implemented using a conventional general digital computer and can be programmed according to the techniques of the present invention. As will be apparent to those skilled in the software art, appropriate software coding can be readily performed by a skilled programmer based on the techniques of this disclosure.

As will be apparent to those skilled in the art, the present invention may also be implemented by assembling application specific integrated circuits or interconnecting a suitable network of conventional device circuits.

The invention also includes a computer program product, which is a storage medium containing instructions that can be used to program a computer to perform a process of the invention, such as a distributed program or content flow control of a distributed network. The storage medium may be any type of disk, including a floppy disk, optical disk, CD-ROM, magnetic-optical disk, ROM, RAM, EPROM, EEPROM, magnetic or optical card, or any type suitable for storing electronic instructions. It may include the medium of. When the device implemented is operated, the device is a physical phenomenon, and the desired result of the present invention is achieved by processing a signal for controlling the device in an appropriate manner.

Obviously, many modifications and variations of the present invention can be made based on the above description. Accordingly, the present invention may be practiced without departing from the scope of the appended claims.

Claims (22)

In an on-demand data system for transmitting on-demand data to a requesting end user unit ("request EUU") over a network, the on-demand data system is A plurality of end user units (“EUUs”) suitable for at least one (“first source EUU”) to receive a data file via the communication network, to store the data and to transmit the data file via the communication network; A server suitable for directing transmission of a data file over said communication network between said plurality of EUUs, The server and always first source EUU; Suitable for causing the server to transmit the data file to the first source EUU via the communication network; Suitable for storing the data file in the first source EUU, And the server is adapted to enable the server to cause the first source EUU to transmit the data file to the requesting EUU via the communication network in response to the command received from the requesting EUU. 2. The on-demand data system of claim 1, wherein the server is additionally suitable for tracking information regarding the location of the data file of the first source EUU. The method of claim 1, wherein the data file is: Full multimedia program; At least one fragment of the entire multimedia program; A combination of a plurality of fragments of the entire multimedia program; and at least one of the data systems on demand. The method of claim 1, further comprising a second source EUU, The second source EUU is suitable for receiving and storing the data file, as the data file is stored by the first source EUU, The server and the second source EUU are suitable for causing the second source EUU to begin transmitting the data file to the requesting EUU if the transmission from the first source EUU meets one or more predetermined criteria. On-demand data system. 2. The on-demand data system of claim 1, wherein the server is suitable for causing the first source EUU to replace a data file in the storage device with at least one other data file based on at least one predetermined criterion. . A server for transferring and managing on-demand data files to a plurality of end user units (“EUUs”) connected via a data communications network, the server comprising: A central processing unit ("CPU"); And a memory connected to and operated by the CPU, wherein the memory includes a program suitable for being executed by the CPU, The CPU and the memory are suitable for distribution and operation to the plurality of EUUs for storing the plurality of data files based on at least one predetermined criterion while tracking the location of the data files of the plurality of EUUs; , The CPU and the memory are suitable for receiving and operating an order from a first EUU for at least one data file, The CPU and the memory are suitable for specifying a location of at least one data file of a second EUU and instructing the second EUU to transfer at least one data file to the first EUU in accordance with the request. Server. The method of claim 6, The CPU and the memory are suitable for receiving and operating an order from a third EUU for a combination of a first data file and a second data file, The CPU and the memory are suitable for operation by designating a location of the first data file stored in a fourth EUU and the second data file stored in a fifth EUU, The CPU and the memory are adapted to instruct the fourth and fifth EUUs to transfer the first and second data files to the third EUU in accordance with the order. 8. The server of claim 7, wherein the first and second data files ordered by the third EUU comprise two fragments from the entire data file. 8. The server according to claim 7, wherein said CPU and said memory are operative to designate and manage locations of a plurality of data files on an order basis and to determine a transmission order of said data files. The method of claim 6, The CPU and the memory are operative to track a path of usage information among the plurality of EUUs, The CPU and the memory are operative to re-distribute data files between the plurality of EUUs for storage in response to the usage information, Said CPU and said memory operative to be adapted to add a new data file for distribution among said plurality of EUUs for storage when said new data file is available. Processor, A modem suitable for connection with a data network to receive data files, A storage unit suitable for storing said data file in response to a command from a server connected to a data communication network, The modem is suitable for transmitting at least a portion of the data file to the second end user unit designated by the server via the data communication network. A method of transferring at least one data file from a central storage device to a plurality of end user units (“EUUs”) over a communication network, the method comprising: a) storing at least one data file on the central storage device; b) initializing a first EUU by sending at least a portion of the data file to a first EUU; c) storing said portion of said data file in said first EUU; d) tracking the path of information regarding the location of said portion of the data file; e) when the second EUU has issued an order for the data file, determining the location of the portion of the data file; f) issuing an instruction to the first EUU for the portion of the data file stored in the first EUU; g) upon receipt of said command, said first EUU comprising transmitting said portion of a data file to said second EUU. The method of claim 12, a) initiating a third EUU by sending at least the portion of the data file to a third EUU for storage; b) tracking information regarding the location of the data file of the third EUU; c) monitoring the transmission from the first EUU to the second EUU; d) if the data transfer from the first EUU to the second EUU falls below a predetermined criterion, issue a command to the third EUU for transfer of the portion of the data file to the second EUU, and the first EUU Issuing an instruction to end the transmission at the; e) upon receipt of the command, the third EUU sending the portion of the data file to the second EUU. A method of transferring at least one on-demand data file to at least one of a plurality of end user units (“EUUs”) over a communication network, the method comprising: a) providing a plurality of data files accessible via said communication network; b) distributing the plurality of data files to a plurality of EUUs for storage; c) tracking information relating to each storage location of the plurality of data files of the plurality of EUUs; d) at least one EUU for storing at least one of the plurality of data files from the plurality of EUUs based on at least one predetermined criterion when the requesting EUU issues an order for at least one of the plurality of data files Specifying a location of; e) causing the identified EUU to send the at least one data file to the requesting EUU. 15. The method of claim 14, wherein the predetermined criteria of step d) for identification is Quality of transmission between each of the plurality of EUUs and the second EUU; Proximity of each of the first plurality of EUUs relative to the second EUU; And a need for each of the plurality of EUUs associated with the second plurality of EUUs. 15. The method of claim 14, wherein the plurality of data files includes multimedia programs and data. 10. A method for transferring an on-demand multimedia program from a remote storage device to a plurality of end user units (“EUUs”) over a communication network, the method comprising: a) storing at least one multimedia program on the remote storage device; b) initializing the first EUU by sending at least a first portion of the multimedia program to a first EUU; c) storing said first portion of said multimedia program in said first EUU; d) initializing a second EUU by sending at least a second portion of the multimedia program to a second EUU; e) storing said second portion of said multimedia program in said second EUU; f) tracking information regarding the storage location of the first and second portions of the multimedia program of the first EUU and the second EUU; g) when a third EUU issues a request for the multimedia program, causing the first and second portions of the multimedia program to be sent to the third EUU; h) upon receiving the first and second portions of the multimedia program, the third EUU assembling to download the multimedia program. 18. The method of claim 17, wherein the multimedia program comprises at least one of a video program, an audio program or a movie program. 18. The method of claim 17, wherein each portion of the multimedia program is encrypted with a predetermined encryption key. A method of transferring at least one data file of a plurality of on-demand data files to a first client over a data communication network with a plurality of clients and servers, the method comprising: a) distributing the plurality of data files to at least one of the plurality of servers and clients for storage based on a predetermined distribution plan; b) tracking each of the data files for its location; c) receiving a request for one of the plurality of data files from the first client; d) designating a location of at least one of the client and the server storing the requested data file; e) instructing at least one of the client and the server to send the requested data file to the first client. 21. The method of claim 20, wherein the predetermined distribution plan is based on at least one of the location of the server and client and the popularity of the data file. A method of performing a VOD service using a communication network, the method comprising: a) providing a plurality of movies accessible through at least one server in the communication network; b) distributing a plurality of set top boxes ("STBs") to a plurality of clients; c) storing a plurality of movies as a fragment or wholly through the STB and the at least one server, and continuing tracking the location of the fragment of the movie; d) upon receiving a request from one of the clients for a movie from the plurality of movies, specifying the location of the movie shortly or entirely; e) causing the movie to be sent to the requesting client as a fragment or wholly, upon positioning the movie as a fragment or wholly between the STB and the at least one server.