US20040216164A1 - Decentralized media delivery - Google Patents

Abstract

A decentralized approach to delivering a media file to a requesting subscriber in a network of subscribers comprises the steps of segmenting the media file into a plurality of segments and distributing the segments of the media file among the network of subscribers, and responding to a request from the requesting subscriber by directing to that requesting subscriber all of the plurality of segments of the media file. All of segments are assembled into the media file and displayed or stored by the requesting subscriber.

Description

• This application claims the benefit of the filing date of U.S. Provisional Patent Application No. 60/396,357, hereby incorporated by reference.[0001]
TECHNICAL FIELD
• This application relates to the field of electronic media delivery, such as video-on-demand, including the secure handling and storage of such media.[0002]
BACKGROUND
• Current options for viewing a movie at home include traveling to a movie rental store to obtain a videotape or DVD copy of the movie. The copy must be returned a few days later. Another option is to select from the limited number of choices that are offered from sources that provide what is known as pay-per-view movies. Cable or broadcast movie channels provide a limited number of selections of movies for display a predetermined times.[0003]
• It is usually not economically feasible for the operator of, for example, a cable television (CATV) system (or other content provider) to provide for delivery-on-demand a large number of movie selections to subscribers because such a system requires a extensive amount of bandwidth between the content provider and each of the subscriber units (televisions or other display devices) of the network.[0004]
SUMMARY OF THE INVENTION
• The present invention addresses the problem of prohibitive bandwidth requirements for a content provider in delivering video-on-demand or other large media files. In short, there is provided a system that shifts the bandwidth requirements away from the content provider and to the network of subscriber units.[0005]
• In one embodiment, a media file representing, for example, a movie is segmented. These segments are distributed among the network of subscriber units. Any one of the subscribers may submit a request to view a movie. In response to such a request, the other subscriber units direct to the requesting subscriber all of the segments, which are then assembled into the complete media file (movie) for display, or stored for later display, on the requesting subscriber's unit.[0006]
• In one embodiment, the subscriber's request is sent to the netrolrk's main server. The main server then instructs the network subscribers to forward copies of the segments stored in those units to the unit of the requesting subscriber. The segments are each encrypted or otherwise encoded to prevent unauthorized viewing of individual segments. When the requesting subscriber has received all segments of the movie, that unit sends a message to the main server, requesting the encryption key to unlock the movie. The main server provides this, and billing information is then recorded in the main server.[0007]
• The segmented and distributed storage of the media file provides a high level of security and a deterrence to piracy. No single subscriber unit has more than a segment of a media file, which segment, by itself, has little value.[0008]
• In another embodiment, the segments of the media file are copied and these copied segments are also distributed to the network subscribers in a manner that provides redundancy to the system so that in the event that a given subscriber unit is unable to provide the requesting subscriber with the segment stored on that given unit, there will be available on other units copies of that segment to complete the media file.[0009]
• It is contemplated that the request for the media file and subsequent responses for directing the segments to the requester can be handled without the intervention of the network's main server by using peer-to-peer architecture or the like.[0010]
• Other advantages and features of the present invention will become clear upon study of the following portion of this specification and drawings.[0011]
BRIEF DESCRIPTION OF DRAWINGS
• FIG. 1 is a block diagram of a system adapted for carrying out the decentralized media delivery of the present invention.[0012]
• FIG. 2 is a depiction of how segments of a movie-type media file are stored on the units of network subscribers.[0013]
• FIG. 3 is a depiction of an alternative way in which segments of a movie-type media file are stored on the units of network subscribers.[0014]
• FIG. 4 is a flow diagram showing how the decentralized media file delivery of the present invention is carried out.[0015]
BEST MODES FOR CARRYING OUT THE INVENTION
• With reference to FIG. 1, a preferred embodiment of the present invention is includes a[0016]network20 of electronically connected subscribers A, B, C, and D. The small number of subscribers depicted here is intended to be representative of, for example, the thousands of subscribers that may be part of a typical cable television (CATV) network. Alternatively, the network can be any other communications network of users or subscribers, such as those linked by a local area network (LAN) or a wide area network (WAN).
• Each subscriber includes a[0017]unit22, which, in a CATV network, can be adapted from a conventional set-top box. Eachsubscriber unit22 includes a central processing unit (CPU)24 that, among other things, is in communication with amain server26 of the network for receiving and providing instructions and data as will be described.
• Each[0018]subscriber unit22 also includes a storage device, such as a conventional hard disk. This device, hereafter referred to assegment storage28, stores segments of one or more media files. It is noteworthy here that the term “media file,” although most often used hereafter to refer to digitized data that represents a movie and that can be processed to display the movie, is intended to also include any type of media file that can be stored and displayed.
• Each[0019]subscriber unit22 is associated with adisplay device30, preferably capable of displaying video information, as well as auser interface32 for receiving and processing infonnation from the user of the subscriber unit. Such aninterface32 may be a convention television remote control for powering the unit and requesting a display of menu options (movie titles, etc) for selection by the user. A speaker system (not shown) is also connected to the subscriber unit for providing audio information.
• In accordance with the present invention, each[0020]unit22 receives from themain server26 one or more segments of a complete media file. The segments are stored in thecorresponding segment storage28. FIG. 2 depicts thesegment storage28 of one unit. Stored there are five different segments S1, S65, S159, S561, S86. Each segment is part of a different movie. In one embodiment, a segment is a digital packet that includes data representing a small portion of the movie (video and audio) as well as a header that includes a packet identifier, descrambling control, and other information. The header identifies the movie and the segment number of the movie so that the movie data may be readily assembled once all of the packets are collected, as will be described.
• FIG. 3 depicts an alternative way of segmenting a media file (movie) for storage in the[0021]segment storage28 of a subscriber unit. Here, several separate segments S1, S5, S9, and S13 of a movie (“Movie A”) are bundled together for storage. The segments are separate in the sense that they represent discontinuous or non-sequential portions of the movie and must be soiled and integrated with the remaining segments (distributed elsewhere in the network) to provide the complete movie. This approach to segmenting the movie provides increased security from piracy since each subscriber A, B, C, etc, will store only very small portions of the movie on the storage device of the unit. If the segments are made very small, to the scale of a few bytes or single bits, decoding of any individual bundle will be virtually impossible. Further, access to the correct method for recombining the segments to recreate the original media file could be stored in a password-protected file, linked to an encryption key, or locked to all devices except the specific hardware device that created the bundled segments.
• Although FIG. 3 shows only bundled segments of a single movie “A,” it will be understood that each[0022]segment storage28 of eachsubscriber unit22 can store a number of such bundled segments from the same or different movies.
• The[0023]main server26 includes acontroller36 that controls the distribution of a multitude of segments over thenetwork20. The segments are delivered from a segment library3S that comprises segments of all movies that are available to the network. In one embodiment, themain server26 includes a segment-tracking module34 for tracking the location of the segments. For example, in some networks not all of thesubscriber units22 may at all times participate in the media-file delivery system of the present invention. Accordingly, the segment-tracking module34 stores the addresses of the participating units and, via a look-up-table or the like, keeps track of which segments are distributed to which units.
• Whenever a subscriber requests a movie, the segment-[0024]tracking module34 provides an efficient way of instructing the remaining units (that is, the ones storing the segments of the requested movie) to forward all of the stored segments to the requesting subscriber. The segment-tracking module34 also permits, for example, occasional testing of the system wherein thecontroller36 from time to time initiates a test movie request (wherein the main server acts as a requesting subscriber) and then compares the received segments with those listed in the segment-tracking module34 to ensure that all segments are timely received. If not, that segment-tracking module34, under the control ofcontroller36 can redistribute the missing segment(s) to other participatingunits22.
• In one embodiment each subscriber will receive and store at least one segment of a movie. Each segment, however, is copied and distributed to a plurality of different subscribers to provide for redundant availability of each segment in the event a subscriber's[0025]segment storage28 becomes inaccessible. As noted, the main server's segment-trackingmodule34 can track which segments are held by each subscriber unit, thereby to optimize the network's redundancy, and to facilitate replacement or redistribution of segments when necessary.
• FIG. 4 shows a flow diagram indicating how the decentralized media file delivery of the present invention is carried out. Associated with the[0026]main server26 is thesegments library38 that is stocked100 with segments of available movies.
• As noted, the[0027]main server26, via thecontroller36 and segment-trackingmodule34, distribute102 the movie segments (including copies of segments to establish the redundancy described above) to all of the participatingsubscriber units22. Such distribution and storage of the segments on the units may be performed in a manner that is automatic and transparent to the users of the units.
• With continued reference to FIG. 4, after the main server receives a[0028]movie request104 from a requesting subscriber (the request made viauser interface32 described above), the server responds106 by sending over the network instructions to the network subscriber units to direct all of the segments of the requested movie to the requesting subscriber.
• The segments received at the requesting unit, comprising a stream of packets as mentioned above, are applied to a demultiplexer[0029]40 (FIG. 1) for header parsing to recover the packet or segment identifier number, descrambling control, and other information. Thesubscriber unit CPU24 and associated buffers (not shown) log the received packets and, once all packets are received, sends a notice to themain server26 that all packets now reside in the unit of the requesting subscriber. Themain server26 upon receiving this notice108 (FIG. 4) responds by transmitting authorization, such as an entitlement control message, to thesubscriber unit110. At that time, an entry is made in the requesting subscriber's billing information to reflect the purchase of the movie.
• Once the authorization is received by the unit, the packets are then descrambled[0030]42 (FIG. 1) and further processed by adecoder44 to strip of header data and extract video and audio data for instant display on the subscriber'sdisplay device30, or for storage as a complete media file (movie) in amass storage device46 associated with the requesting subscriber unit.
• It is noteworthy here that the role of the[0031]main server26 in receiving the movie request and instructing the subscribers to forward the segments to the requesting subscriber unit can be handled by other means, such as by use of a peer-to-peer approach whereby the request is provided directly to all of the network subscribers rather than being relayed from themain server26. The subscriber units that have the requested segments stored therein respond by automatically forwarding those segments to the requesting subscriber. As is the case with the prior described embodiment (main server receives request and instructs subscribers) the sending and collection of segments occurs automatically, without intervention by any subscriber (apart form the initial request via theuser interface32 and mentioned above).
• While the present invention has been described in terms of preferred embodiments, it will be appreciated by one of ordinary skill in the art that modifications may be made without departing from the teachings and spirit of the foregoing.[0032]

Claims (19)

1. A method of delivering a media file that is requested by a requesting subscriber of a network of subscribers, comprising the steps of:

segmenting the media file into a plurality of segments;

distributing the segments of the media file among the network of subscribers for storage on respective units of the subscribers; and

responding to a request from the requesting subscriber by directing to that requesting subscriber all of the plurality of segments of the media file.

2. The method ofclaim 1 including the step of assembling into the media file all of the segments that are directed to the requesting subscriber.

3. The method ofclaim 2 including the step of storing the assembled media file in a storage device of the requesting subscriber.

4. The method ofclaim 1 including the step of copying the segments of the media file and wherein the distributing step includes distributing the copied segments among the network of subscribers in a manner such that any particular segment of the media file is stored on at least two different subscriber units.

5. The method ofclaim 1 including the step of preventing display of the individual segments of the media file by the subscribers to whom the segments are distributed.

6. The method ofclaim 2 including the step of allowing display of only the assembled media file by providing authorization to the requesting subscriber.

7. The method ofclaim 1 wherein the distributed segments represent a first media file, the method including the step of distributing among the network of subscribers a plurality of segments of a second media file.

8. The method ofclaim 1 including the steps of:

directing the request to a controller; and

relaying the request from the controller to the network of subscribers, whereby the controller thereafter instructs the network of subscribers to direct to the requesting subscriber all of the plurality of segments of the media file.

9. The method ofclaim 1 including the steps of:

directing the request to the network of subscribers, whereby in response to the request the network of subscribers directs to the requesting subscriber all of the plurality of segments of the media file.

10. The method ofclaim 1 wherein the distributing step includes tracking the location of the distributed segments in the subscriber network.

11. The method ofclaim 1 wherein the segmenting step includes forming a bundle of several discontinuous portions of the media file.

12. The method ofclaim 1 including the step of encrypting each of the segments of the media file.

13. The method ofclaim 1 wherein segmenting the media file includes segmenting the file into a plurality of packets that include header information to enable assembly of the packets into the media file and storage of the media file in the unit of the requesting subscriber.

14. A method of storing a media file, such as a movie, comprising the steps of:

providing a network of subscribers;

distributing discrete segments of the movie to storage locations of at least some of the subscribers; and

tracking the storage locations of the segments thereby to enable subsequent collection and assembly of the segments into the media file.

15. The method ofclaim 14 including the step of preventing display of any stored, discrete segment of the movie by the subscribers.

16. A subscriber network for storing a media file comprising:

a number of subscriber units each unit including storage device for storing a segment of the media file;

a plurality of segments of the media file that are adapted for assembly into the media file, the segments being distributed among the subscriber units; and

network means for directing to a requesting one of the subscribers all of the segments of the media file.

17. The network ofclaim 16 wherein the media file comprises a movie.

18. The network ofclaim 17 wherein the segments each comprise several discontinuous portions of the movie.

19. The network ofclaim 16 further comprising a plurality of segments of another media file that are adapted for assembly into the other media file, the plurality of segments of the other media file being distributed among the subscriber units.

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