Local digital asset storage management technique

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LOCAL DIGITAL ASSET STORAGE
MANAGEMENT TECHNIQUE

FIELD OF THE INVENTION

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The present invention pertains to the management and storage of digital assets, such as audio signals, moving picture signals, still pictures, executable code, text and the like, and combinations thereof (e.g., audio-visual programs, electronic games, web pages, etc.), in the storage device of a user appli- 10 ance, such as a personal video recorder, set top box, mobile phone or storage server.

INCORPORATION BY REFERENCE

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Applicant hereby expressly incorporates by reference herein International Patent Application No. WO 002003024036A1, entitled "Method And System For Scheduled Streaming Of Best Effort Data," published Mar. 20, 2003. 20

BACKGROUND OF THE INVENTION

A digital asset is a digital representation of information that can be used, i.e., moved, copied, modified, rendered or 25 executed. Common examples of digital assets are audio signals (such as songs, mobile phone ring tones and movie sound tracks), image signals (such as moving pictures, still images, fonts and clip art), text and other file-based data (such as news articles, databases and spreadsheets) and executable code 30 (such as computer programs). Digital assets may include different combinations of these items. For example, a typical movie may include one or more video programs, one or more accompanying audio signals, closed-captioning text, etc. Also, more complicated composite digital assets may be ere- 35 ated including individual component digital assets.

Absent other controls, digital assets are normally amenable to the following types of uses by users: copying (i.e., making an additional replica of all or part of the digital asset), movement (i.e., transferring the digital asset from one location to 40 another), rendering (i.e., converting all or part of the digital asset to humanly perceivable form, such as by displaying or reproducing an audible sound), modification (i.e., editing the digital asset) and execution (i.e., causing a programmable apparatus to treat the digital asset as executable instructions 45 and to act as directed by such instructions). Digital rights management ("DRM") refers to managing or controlling the use of digital assets. Many different types of controls have been examined including absolutely preventing certain types of uses or permitting certain uses only under certain condi- 50 tions. For instance, it might be of interest to allow a user to watch a certain audio-visual program but to prevent the user from copying the audio-visual program. This is an expression of the rights that are intended to govern, i.e. to be enforced on, the audio-visual program digital asset. DRM institutes mea- 55 sures to cause apparatuses to be governed by such rights.

Historically, information such as audio programming or audio-visual programming has been delivered in a broadcast fashion and according to the schedule of a broadcaster. For instance, a radio broadcaster would choose live and pre- 60 recorded audio, such as songs, newscasts, sportscasts, interviews, etc. and an appropriate schedule for delivering such audio. Likewise, a television broadcaster would choose live and pre-recorded audio and video, such as television shows, newscasts, sportscast, program guides, etc., and an appropri- 65 ate schedule for delivering such audio and video. Such audio or audio-video programming would then be broadcast to all

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reception capable consumer appliances, such as radio receiver sets or television receiver sets, strictly according to the schedule of the broadcaster. A consumer desiring to listen to and/or watch such programming would have to tune their respective receiver set at the appropriate time to listen to or view a particular audio or audio-visual program segment. (Herein, "programming segment" means a particular portion of a signal with a definite start and stop time, such as a television show, radio show, commercial, etc.) If the consumer did not use their radio receiver set or television receiver set at the appropriate time, the user would miss all or part of the desired programming segment.

Equipment manufacturers developed consumer playback and recording appliances for playing back and recording audio-visual programs, such as video cassette recorders ("VCR's"), DVD players, DVD recorders and personal video recorders ("PVR"), which are also commonly referred to as digital video recorders ("DVR"). For example, a PVR is distributed under the brand name TiVoTM by a company called TiVo, Inc.TM, located in Alviso, Calif. This PVR contains a fixed magnetic disk recording device or "hard disk drive." The PVR is connected to the phone network and receives programming segment information (i.e., the name of each programming segment, the program number on which the segment will appear and the start and stop times of the programming segment) in the form of an electronic program guide ("EPG") that can be presented to the user through a graphical user interface. Specifically, the electronic program guide is displayed in tabular form on a display device as part of an on-screen display. The user can then use simple navigation controls (i.e., left, right, up, down, select, etc.) for choosing upcoming programming segments to be recorded. Other PVR's include a combined DVD recorder/PVR marketed by PanasonicTM, a company located in Osaka, Japan and a combined cable television set-top box/PVR marketed by Scientific AtlantaTM, a company located in Lawrenceville, Ga. This latter set-top box appliance also receives, tunes, demodulates, demultiplexes, deciphers and decodes ("decompresses") the audio-visual programming during normal real-time, i.e., non-recorded playback, television viewing by the user.

Not all digital assets are available from a broadcast network. Typically, executable code is only available for purchase on a pre-packaged storage medium, such as a DVD or CD disc, or by download from a computer network, such as the Internet. Some cable operators do broadcast music, but they do not publish broadcast schedules, so it is difficult for a user to pre-arrange to record a desired song. Furthermore, many movies are never broadcasted or are not broadcasted until some later date. Rather, such movies are available only, or at least initially are available only, for purchase or rental on pre-packaged stored media, such as DVD discs or VCR tapes. The disadvantage to the user of obtaining digital assets by pre-packaged stored medium is that there is a delay between the user's desire to use the digital asset, which is often spontaneous, and the availability to the user of the pre-packaged stored medium containing the content.

Many digital asset owners are still reluctant to freely deliver their digital assets via the Internet, because they fear that this will encourage wide-spread unauthorized copying, distribution and use of the digital asset. For instance, few movies are legally authorized for delivery to the user via the Internet. In any event, even using a typical high speed connection, it is generally not possible to deliver the movie for viewing in real-time, on account of the non-continuous or bursty nature of the individual networks that make up the Internet. As an alternative, it is theoretically possible to deliver a movie via the Internet for local storage prior to viewing, thereby circumventing the burst delivery short-coming of the Internet. However, delivery of an entire movie, which can be on the order of 10 gigabytes total in length (depending on the duration of the movie and manner by which 5 it is compressed), would nevertheless take on the order of 12 hours assuming a very high average delivery rate of 2 megabits per second via a broadband Internet connection. This delay might not be any shorter than the time it takes the user to visit the local movie rental store and therefore might not 10 offer an attractive alternative for the consumer. This is especially true if the delivery rate for the movie is, on average, 1 megabit per second or lower, which may be more typical for most conventional broadband Internet connections.

Separately, network service providers have attempted to 15 respond to consumer demand for a more flexible viewing/ listening schedule. For example, many cable service providers now provide so-called "video-on-demand" ("VOD") service. In a typical VOD service, such as is provided by Time Warner CableTM of New York and New Jersey, a company 20 located in New York, N.Y, the user is provided an EPG which lists certain audio-video programming segments that can be chosen by simple on screen navigation controls. Upon selecting a particular audio-visual program segment, a head end transmitting station attempts to deliver the selected audio- 25 visual programming segment to the particular user who selected the program. The user has some playback control functionality similar to a VCR; using a remote controller, the user can fast forward, reverse, pause, stop and restart a selected audio-visual programming segment. However, this 30 system has some short-comings. First and foremost, a communication channel must be available for each specific user who desires to use the VOD service at the same time. This has proved to be a challenge for cable service providers who are also simultaneously trying to deliver traditional broadcast 35 audio-visual programming, high speed cable modem service and telephone service all on the same communication medium. Second, the server and transmission equipment at the cable head end station must be capable of delivering enough copies of all desired audio-visual programs that are 40 demanded at that moment. Consider the specific problem of a very popular movie that has just been made available on a certain Friday night, starting at 5:00 pm. If the demand is extraordinarily high for that particular movie, many consumers will attempt to demand the same movie simultaneously, 45 albeit with slight time differences between the respective viewers. For instance, if the most popular time for watching a movie is between 7:00 and 8:00 PM, it is quite possible for one user to demand that the movie start at 7:00 sharp, another at 7:05 and 30 seconds, another at 7:17 and 25 seconds, etc. 50 Thus, the server and transmitter equipment must be able to deliver each of these multiple copies of the movie at the requisite demanded time. More often than not, these constraints of the network prevent fully-flexible delivery of VOD or curtail the number of different audio-visual programming 55 segments that can be offered to the user at any one moment in time.

Yet another solution has been provided for delivery of VOD service to the user which attempts to leverage all of the benefits, and circumvent all of the short-comings, of the vari- 60 ous networks and consumer appliances mentioned above. Specifically, MovieBeam, Inc.TM, a company located in Burbank, California, has provided a unique VOD solution that is achieved using special PVR-like player appliances available to the consumer user and a head end broadcast service for 65 distributing audio-visual programming segments. The system works as follows. The consumer user can purchase the player

appliance from a store. The player appliance has an antenna that is capable of receiving a VHF or UHF signal, a modem jack for plugging the player into the user's phone line and audio-video output jacks for connecting to a television set and loud speakers. Internally, the player has a high capacity fixed magnetic disk. At the time of purchase, the magnetic disk has already been pre-loaded with the most current selection of movies available to other consumer users of the MovieBeamTM service. The user connects the player appliance to the user's phone line, to a television antenna and to the user's television and sound system. Immediately, the user can access any one of the pre-recorded movies on the player appliance for playback with full navigation controls (e.g., reverse, fast forward, pause, stop and restart). Meanwhile, new movies are broadcast from a terrestrial broadcast head end station via the VHF or UHF channels, which are received by the user's player via the antenna. This broadcast and replacement occurs without request by the user and more or less continuously over time and invisibly from the perspective of the user—the user need not perform any action to initiate the replacement of movies. This unsolicited delivery of information from a source (the head end station) to a destination (the player) is referred to as a "push" delivery model. The replacement of existing movies on the player appliance by the new movies refreshes or rotates the selections available to the user.

As a business model, the user pays a fee to purchase the player appliance, e.g., $199, plus a rental fee of, e.g., $1.99$4.99 per movie rented. The player communicates customer usage (i.e., the individual movie rentals) to a central billing facility via a modem built into the player and the telephone connection to the player. The player is delivered with 100 different movies and movies are replaced at the rate of about 10 movies per week.

The MovieBeamTM service provides the following advantages:

(1) Bandwidth utilization of the broadcast channel is maximized in that movies need only be delivered once to all consumers, yet can be played by multiple subscribers and multiple times.

(2) Similar to VOD, the consumer can immediately and spontaneously view a movie at the time of his or her choosing, provided it is already stored in the library maintained on the fixed magnetic disk of the player.

(3) Similar to a VCR, PVR or DVD disc player, the consumer has full playback control including fast forward, reverse, pause, stop and restart capability.

(4) Similar to the PVR, the consumer can quickly switch between different movies without having to eject and load different removable storage media.

(5) The pricing is competitive with movie rental retail outlets yet provides instant access to the movies.

(6) The consumer need not return the storage medium containing a rented movie to a remote location.

It is desirable to provide a system that facilitates the local management of digital assets, e.g., in a push model delivery system, such as the MovieBeamTM system. However, the invention is amenable to other kinds of networks and consumer/end-user appliances, such as cable networks and set top boxes, and cellular networks and mobile phones.

SUMMARY OF THE INVENTION

A technique is described for managing the local storage of digital assets, such as audio, (moving or still) pictures, text, executable code and combinations thereof, in the storage device of a user appliance, such as a personal video recorder, set top box or mobile phone. A digital asset is received that is 5

intended for local storage in the storage device and that has been pushed down from a source. A rank order is assigned to each digital asset stored or to be stored in a storage device that has a finite capacity storage space for storing digital assets. The assigned rank orders of one or more of the digital assets 5 are repeatedly examined and a digital asset having a rank order that is lowest among the examined rank orders may be deleted. Each rank order is assigned based on predefined default ranking rules and user instructions pertaining to one or more of the digital assets that are capable of causing a devia- 10 tion from the default ranking rules, if any have been provided by the user. A signal may be provided containing executable instructions that can be executed at programmable electronic circuits for performing the above steps. Such a signal may be stored on a storage medium. A system for performing the 15 above steps may include a receiver for receiving the digital assets and a processor for assigning ranking orders and for repeatedly examining the ranking orders and deleting digital assets with low ranking orders.

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BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an illustrative network in which the invention may be deployed.

FIG. 2 shows an illustrative apparatus according to the 25 invention.

FIG. 3 shows an illustrative layered environment in which the invention operates.

FIG. 4 shows an exemplary method for receiving and ranking digital assets in a cache system in accordance with the 30 present invention.

FIG. 5 shows an exemplary method for ranking/re-ranking and/or deleting digital assets in a cache system in accordance with the present invention.

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DETAILED DESCRIPTION OF THE INVENTION

An illustrative embodiment of the invention is an electronic appliance that receives digital assets by a push delivery model and stores such digital assets. However, the invention is not 40 strictly limited to the push delivery model and also applies to a pull delivery model (in which the destination must issue a request to a source in order to cause the source to transfer information to the destination) or a hybrid of the two models. Also, the invention is illustrated for an appliance that only 45 receives digital assets, namely, an appliance that is strictly a playback device. However, the invention also applies to appliances that function as local servers, i.e., which receive and store digital assets for later transfer to yet other appliances for storage, playback and/or rendering. The invention is also 50 illustrated for a network in which digital assets are primarily transmitted by RF or microwaves in a broadcast fashion to all consumer appliances within the range of coverage of the transmitting tower(s) or satellite(s). The invention is specifically illustrated for an ATSC compliant terrestrial broadcast 55 signal. However, the invention applies to other terrestrial broadcast signals, such as DVB-T or DVB-H compliant signals and other types of wired and wireless broadcast signals such as DVB-S, DVB-S2 and DVB-C compliant signals. Likewise, the digital assets in the description below illustra- 60 tively are movies, possibly also including coming attractions, textual descriptions, etc. However, the digital assets can also be of any type including audio signals, still images, readable text, databases, spreadsheets, executable code, games, web pages, etc. Also, the invention furthermore applies to other 65 types of appliances such as mobile phones, set top boxes or personal digital assistants. Transmission of digital assets can

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also be achieved by the following standards: IEEE 802.11a/ b/g or 802.1 In ("WiFi"), 802.16e ("WiMAX"), CDMA, GSM, TDMA, etc.

FIG. 1 shows a basic end-to-end system in which the invention may be deployed. At a head end station 300, one or more servers 302 collect different types of digital assets for transmission. As shown, the digital assets may include one ormore file-based content 304 (e.g., text, spreadsheets, databases, executable code, games, etc.), one or more multimedia types of content 306 (e.g., songs, sounds, ring tones, still images, moving picture images, movies, text, etc.) or content 308 periodically retrieved from the Internet 310 (e.g., web pages, audio programming segments, audio-visual programming segments, etc.) by the server(s) 302. Illustratively, the server(s) 302 are zBandTM servers, i.e., server computers that also run the zBandTM Director software, available from TANDBERG Television Inc.TM. At the appropriate time, and under control of the zBandTM server(s), aggregated digital assets 312 and possibly other content are delivered in a controlled fashion to an injector 314, which may be an SMR24TM, SMR-25 or SMR-26 Source Media RouterTM, a MediaPlex-20 Video Services RouterTM or an iPlex Video Headend PlatformTM, all of which are available from TANDBERG Television Inc. The injector 314 inserts the digital assets 312 into another MPEG-2 Transport Stream, e.g., an ATSC compliant MPEG-2 Transport Stream carrying ordinary broadcast television signals. The digital asset data, itself, is placed into Internet Protocol ("IP") packets, which in turn are placed into MPEG-2 Transport Stream packets that are remultiplexed with an existing MPEG-2 Transport Stream 316 carrying the ordinary broadcast television signal(s). The remultiplexed MPEG-2 Transport Stream 318 carrying the television signals and the digital asset signals are then modulated by a modulator 320, e.g., according to 8-VSB modulation, and the modulated signal is transmitted by an antenna 322 on an appropriate frequency channel to multiple consumer terminals 324 simultaneously.

The MPEG-2 Transport Stream 318 may be modulated and transmitted from the head end station 300 to the consumer terminals 324 in other ways. For instance, the signal 318 may be modulated using an OFDM modulation according to the DVB-T or DVB-H standards and transmitted terrestrially via the antenna 322. The signal 318 may be QPSK modulated according to the DVB-S standard and transmitted partly through space, via a satellite dish 326 and satellite (not shown). The signal 318 may be QAM modulated according to the DVB-C standard and transmitted by a cable plant 328. The signal 318 can also be modulated according to the V.92 standard or ADSL standards and transmitted via a telephone line 330. The signal 318 may also be OFDMA modulated according to the IEEE 802.16e standard and transmitted via the antenna 322. Other wireless transmission possibilities include those that accord with GSM, TDMA, CDMA and/or 802.11a/b/g or 802.lln. An antenna, such as antenna 16, a wireless NIC 15 or other suitable structure may be used for this purpose.

FIG. 2 shows an illustrative electronic receiver appliance 1 that may form part of a consumer terminal, e.g. consumer terminal 324 in FIG. 1. The appliance 1 has an analog front end 10 for receiving a transmitted signal, such as aVHF/UHF RF or microwave signal tuner, a demodulator and a channel decoder. Illustratively, the appliance receives the broadcast transmitted signal via an antenna 16 according to the ATSC standard which uses 8-VSB. However, the appliance could alternatively receive another type of signal, e.g., a DVB-S signal via the dish shaped antenna 14. Also, in the case of some other type of communication, such as according to the