KR20030048139A - Selective inactivation and copy-protection - Google Patents

Abstract

The present invention receives at least one DOD service 706, 707 and indicates that the at least one expiration information packet is a first set time, which is no longer accessible to the at least one DOD service afterwards, Receiving at least one associated expiration information packet corresponding to the at least one DOD service (704); And storing at least a portion of the at least one DOD service at a memory location 708. A method for selectively preventing access by a client to an on-demand data (DOD) service. In a second embodiment, the method further comprises receiving at least one associated copy protection information packet corresponding to the at least one DOD service 804, 834, 854, wherein the at least one copy is received. The prevention information packet indicates a second set time, at which duplication of the at least one DOD service is prevented.

Description

Selective INACTIVATION AND COPY-PROTECTION}

On-demand data (DOD) systems are a new alternative to traditional cable television systems that provide service on a regularly scheduled time. One problem faced by the video-on-demand (VOD) and DOD industries is to prevent clients from simply storing DOD services. This reduces repetitive orders for previously received DOD services and may result in illegal sharing or sale of DOD services to non-clients. Another problem is that if a client downloads a DOD service, he can use the service indefinitely. If the client orders the selected DOD service, he does not need to order the service again.

The following is a general discussion of widely used digital broadcasting systems. In general, in a digital broadcast system, a bit stream, multiplexed according to the MPEG-2 standard, consists of a packet containing a "packetized elementary stream (PES)" packet and other necessary information. "Transport stream". A "packeted elementary stream (or PES)" packet is a data structure used to transmit "elementary stream data". "Basic Flow" is a generic term for one of (a) coded video, (b) coded audio, or (c) other coded bit streams transmitted in a series of PES packets with one stream ID. to be. Transport streams support multiplexing of video and audio compression streams from one program with a common time base.

1 of the prior art illustrates packetizing compressed video data 106 of a video sequence 102 into a stream of PES packets 108 and then into a stream of transport stream packets 112. do. In particular, video sequence 102 includes compressed video data 106 associated with various headers 104. The video sequence 102 is parsed into segments of various lengths, each with an associated PES packet header 110, to form a PES packet stream 108. Thereafter, the PES packet stream 108 is parsed into segments, each of which is provided with a transport stream header 114 to form a transport stream 112.

2 of the prior art is a block diagram illustrating a digital broadcast system 200 including a digital broadcast server 202 and a set-top-box 204 suitable for processing digital broadcast data. In the digital broadcast server 202, video data is provided to a video encoder 206 which encodes the video data according to the MPEG-2 standard. The video encoder 206 provides the encoded video 208 with a packetizer 210 that packetizes the encoded video 208. Thereafter, the packetized encoded video 212 provided by the packetizer 210 is provided to a transport stream multiplexer 214.

Similarly, in the digital broadcast server 202, audio data is provided to an audio encoder 214 that encodes the audio data. The audio encoder 214 provides the encoded audio 218 to a packetizer 220 that packetizes the encoded audio 218. Thereafter, the packetized encoded audio 222 provided by the packetizer 220 is provided to the transport stream multiplexer 214.

The transport stream multiplexer 214 multiplexes the encoded audio and video packets and sends the resulting multiple streams to the set-top-box 204 via the distribution infrastructure 224. This distribution infrastructure 224 may be, for example, a telephone network and / or cable TV (CATV) system, employing optical fibers and implementing asynchronous transfer mode (ATM) transmission protocols. Can be. At the set-top-box 204, on the remote end of the distribution infrastructure 224, a transport stream demultiplexer 230 receives the multiplexed transport stream. Based on the packet identification number of a particular packet, the transport stream demultiplexer 230 separates the encoded audio and video packets and directs the video packet to a video decoder 232 via a link 238, and The audio packet is provided to an audio decoder 236 via a link 240.

The transport stream demultiplexer 230 also provides timing information to a clock control unit 236. The clock control unit 236 uses both the video decoder 232 and the audio decoder 236 based on timing information provided by the transport stream demultiplexer 230 (eg, based on PCR field values). To provide the timing output. The video decoder 232 initially provides video data corresponding to the video data provided to the video encoder 206. Similarly, the audio decoder 236 initially provides audio data corresponding to the audio data provided to the audio encoder 216.

3 of the prior art shows a simplified functional block diagram of the VOD system 300. At the heart of the VOD system 300 is a video server 310 that transmits a digital movie to the distribution infrastructure 314, inherent in the movie storage system 312. This distribution infrastructure 314 may be, for example, a telephone network and / or cable TV (CATV) system that employs optical fiber and implements an asynchronous transmission scheme (ATM) transmission protocol. The distribution infrastructure 314 transmits the movie to individual homes based on routing information provided by the video server 310.

The VOD system 300 also includes a number of VOD STBs 304 suitable for processing VOD in the VOD system 300. Each STB 304 receives and decodes a digital movie and converts it into a signal for display on a TV set or A / V monitor.

4 of the prior art shows a general view of a DOD system 320 having a bidirectional client-server architecture. The DOD system 322 includes a DOD server 322 coupled bidirectionally with a plurality of DOD clients 324 via a communication link 326. As will be appreciated, the VOD system 300 of FIG. 3 is a specific example of the DOD system 320.

In broad terms, the operation of the DOD system 320 adheres to the well-known client-server model as follows. In certain manners, typically, through the transmission of an Electronic Program Guide (EPG) by the DOD server 322, the clients 324 are informed of available on-demand data. Using the reference EPG, the requesting DOD client 324 orders specific data from the DOD server 322 via the communication link 326. After the DOD server 322 interprets the client's request, it prepares the client's specific data in a format suitable for use by the requesting client 324.

When the specific data of the client is prepared, the server 322 transmits the specific data of the client to the requesting client 324. The requesting client 324 receives, via a specially allocated portion of the communication link 326, specific data of the requested client in a format suitable for reading. Specific data of the requested client is provided to the end user in a format prepared for presentation by the DOD client. The processing of this client-server is described in more detail below with reference to FIGS. 5-6.

Although communication link 326 may be a true bidirectional communication medium, the infrastructure is not conventional. Instead, current typical implementations install existing infrastructures, such as fiber cabling and telephone lines, to implement the necessary bidirectional communication. For example, if an existing telephone line can be used for transmission of the client's request, the fiber optic cable can be used for transmission of the server to the client's specific data.

Referring to FIG. 5 of the following prior art, the scheme 340 of a bidirectional DOD server according to the prior art is described in detail. In a first step 342, the DOD server identifies available slots within the available transmission bandwidth. In a next step 344, the DOD server prepares and sends the appropriate EPG to each client. It will be appreciated that different EPGs may be sent for individual clients depending on factors such as subscription level, available services, personal settings, payment history, and the like. In some cases, in a next step 346, the DOD server receives an order for specific data from a particular client. The order includes information indicative of the identity of the client. Thereafter, at step 348, the DOD server identifies a particular client from the information included with the order. Step 348 may include retrieving specific data of the client from the persistent storage device and preparing a suitable channel server for data transmission.

In step 350, the DOD server assigns an available slot to the client. In step 352, the DOD server prepares specific data of the requested client for transmission in a suitable format for the requesting client. Continuing with step 354, the DOD server sends client specific data to the requesting client over the allocated bandwidth.

In step 356, the receiving client's set-top-box (STB) stores the requested DOD service on an internal hard drive. This DOD service can be accessed by the client at a given time. DOD services such as movies may be recorded by the VCR attached to the STB. No device can be used to prevent clients from accessing these stored services at any future point in time. No device can be used to prevent unlimited duplication of these stored services.

Referring next to FIG. 6, a client's method 360 for retrieving on-demand data is described in detail. In the coordination step 362, the DOD client coordinates with the appropriate channel program, and in a reception step 364, the DOD client receives the EPG sent by the DOD server. In a next step 366, the DOD client provides EPG information to the DOD user, and in step 368, a request for specific data is received from the DOD user. Thereafter, in step 370, the DOD client orders that the DOD server provide specific data of the requested client. In step 372, the DOD client adjusts to the allocated bandwidth in anticipation of the specific data of the requested client. Thereafter, in step 374, the DOD client receives in a format suitable for reading specific data of the requested client through the allocated bandwidth. Thereafter, in step 376, the client stores the requested data in a DOD receiver with an internal hard drive. The stored data can be used by the client for an unlimited period of time.

As the discussion above reflects, no prior art system provides a way to limit the useful life of a downloaded DOD service. No prior art system provides a way to limit the replication or replication characteristics of the downloaded DOD service. Therefore, it is desirable to provide a method for limiting the useful life of a downloaded DOD service. Furthermore, it is desirable to provide a method for limiting replication characteristics resulting from downloaded DOD services. Also required is a method for restricting replication of downloaded DOD services.

The present invention relates to data-on-demand (DOD) and digital broadcast technologies. In particular, the present invention teaches a method and apparatus for deactivating a DOD program and preventing copying of the DOD program.

Figure 1 of the prior art illustrates packetizing compressed video data into a packet stream and a transport packet stream;

2 of the prior art is a block diagram of a system according to the MPEG-2 standard;

3 of the prior art is a simplified functional block diagram of a VOD system;

4 of the prior art illustrates a DOD system adhering to the bidirectional client-server architecture of the prior art;

Figure 5 of the prior art shows the manner of the DOD server for providing the DOD service using a specific data transmission apparatus of the client;

Figure 6 of the prior art shows the manner of the DOD client for receiving and storing the DOD service using the DOD receiving apparatus;

7 is a block diagram of a digital broadcast server according to an embodiment of the present invention;

8 is a block diagram showing the hardware structure of a general purpose STB according to a preferred embodiment of the present invention;

9 is a flow diagram illustrating a computer-implemented scheme for receiving DOD services with a limited useful life, in accordance with one embodiment of the present invention.

10 is a flow diagram illustrating a computer executable manner for accessing a selected DOD service with associated expiration information stored in a DOD receiver, in accordance with an embodiment of the present invention.

11 is a flow diagram illustrating a computer executable manner for accessing a selected DOD service with associated copy protection information, in accordance with an embodiment of the present invention.

12 is a flow diagram illustrating a computer-implemented scheme for receiving DOD services that are copy protected, in accordance with an embodiment of the present invention. And

FIG. 13 is a flow chart illustrating a copy protection process for a DOD service previously stored according to the process of FIG.

The present invention teaches a method and system for a DOD service in which the DOD service received and stored by the DOD receiver is selectively deactivated to be accessible only for a limited period of time. The present invention also teaches a method and system for limiting replication characteristics resulting from downloaded DOD services. This includes a general purpose digital data system, a general purpose STB, and various methods for manipulating and controlling such a digital service.

A first embodiment of the present invention provides that at least one expiration information packet receives at least one DOD service, indicating a first set time, at which the at least one DOD service can no longer be accessed. Receiving at least one associated expiration information packet corresponding to one DOD service; And storing at least a portion of the at least one DOD service at a memory location. In a second embodiment, the method further comprises at least one corresponding to at least one DOD service, wherein the at least one copy protection information packet indicates a second set time, at which replication of the at least one DOD service is stopped. And receiving an associated copy protection information packet.

As various types of set-top-boxes become more common, it is important to recognize that they are often embedded in units, such as TVs or computers, rather than being installed on top or sides. Those skilled in the art will recognize that references to all STBs apply equally to embedded, so that the two have the same meaning.

In the following detailed description of the embodiments, reference is made to the drawings, which are attached and are part of the embodiments. The drawings illustrate, by way of illustration, specific embodiments in which the invention may be practiced. The above embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, and other embodiments may be utilized and structural, logical and electrical modifications as well as other modifications may be made without departing from the spirit and scope of the invention. This should be recognized.

The present invention teaches a method and system for a DOD service that has been selectively deactivated so that the DOD service received and stored at the DOD receiver can be accessed only for a limited period of time. The present invention also teaches a method and system for limiting replication characteristics resulting from downloaded DOD services. This includes a general purpose digital data system, a general purpose STB and various methods for manipulating and controlling such a digital service. Although the above describes the present invention as used in a unidirectional broadcast system, the present invention can be equally applied to a bidirectional broadcast system.

7 illustrates a structure of a DOD server 450 according to an embodiment of the present invention. The DOD server 450 is coupled via a data bus 506, as shown, a plurality of channel servers 411, a plurality of ups, each corresponding to a channel server 411. Up converters 412, synthesis amplifier 414, central control server 502, and central storage 504. As described below, the central control server 502 not only initiates real-time transmission when the channel servers 411 are ready, but also controls off-line operations of the channel servers 411. . The central storage 504 typically stores data files in digital format. However, any suitable large capacity persistent data storage device may be used.

In a typical embodiment, the data files stored in the central storage device 504 are standard network interfaces (e.g., for example) by any authorized computer, such as the central control server 502, connected to the network. It can be accessed via an Ethernet connection. The channel servers 411 provide data files retrieved from the central storage 504 according to instructions from the central control server 502. Scheduling of digital data retrieval and digital data transmission for the DOD is performed "off-line" to sufficiently prepare each channel server 411 for real-time data transmission. Each channel server 411 notifies the central control server 502 when it is ready to provide a DOD, at which point the central control server 502 controls the channel servers 411 to initiate DOD transmission. can do.

In a preferred embodiment, the central control server 502 includes a graphical user interface (not shown) that allows a service provider to schedule data transfers by drag-and-drop operations. In addition, the central control server 502 authenticates and controls the channel servers 410 to start or stop according to a transmission matrix. A system and method for providing a unidirectional DOD broadcast matrix is disclosed by Khoi Hoang, filed on May 31, 2000, filed with application number 09 / 584,832, entitled SYSTEMS AND METHODS FOR PROVIDING VIDEO ON DEMAND SERVICES FOR BROADCASTING SYSTEMS. It is taught in a patent application, which is incorporated herein by reference.

Each channel server 411 is assigned to a channel and coupled to up-converter 412. The output of each channel server 411 is a quadrature amplitude modulation (QAM) intermediate frequency (IF) signal having a suitable frequency for the corresponding up-converter 412. The QAM-modulated IF signal depends on the standard applied. The standard currently applied in the United States is the data-over-cable-systems-interface-specification (DOCSIS) standard, which requires an IF frequency of approximately 43.75 MHz. Preferred channel servers 411 are described in more detail below with reference to FIG.

The up-converters 412 convert IF signals received from the channel servers 104 into radio frequency signals (RF signals). RF signals, including frequency and bandwidth, depend on the channel required and the standards applied. For example, under the current US standard for cable television channel 80, the RF signal has a frequency of about 559.25 MHz and a bandwidth of about 6 MHz.

The output of the up-converters 412 is applied to the synthesizer / amplifier 414. The synthesizer / amplifier 414 amplifies, adjusts and synthesizes the received RF signals and then outputs the signals to the transmission medium.

8 illustrates a general purpose STB 600 in accordance with an embodiment of the present invention. The STB 600 includes a QAM demodulator 602, a CPU 604, a local memory 608, a buffer memory 610, a decoder 612 with video and audio decoding capabilities, and a graphics overlay module. overlay module 614, user interface 618, communication link 620, and a high speed data bus 622 coupling these devices, as shown. The CPU 602 selects data in response to a client request, decodes the selected data, decompresses the decoded data, recombines the decoded data, and executes the local memory 608 or the buffer memory ( 610 stores the decoded data and controls the overall operation of the general purpose STB 600 for transmitting the stored data to the decoder 612. In a typical embodiment, the local memory 608 includes both non-volatile memory and fixed memory, and the buffer memory 610 includes volatile memory.

In one embodiment, the QAM demodulator 602 includes a transmitter and receiver module and one or more of the following: secret encryption / decryption module, forward error correction decoder / encoder, tuner controller, downstream and upstream processor, CPU and memory interface Circuit. The QAM demodulator 602 demodulates the signals to receive, sample, and recover the modulated IF signals.

In an exemplary embodiment, when access is applied, the decoder 612 decodes at least one data block to convert the data block into images displayable on an output screen. The decoder 612 supports commands from subscribing clients, such as play, stop, pause, step, rewind, fast forward, and the like. The decoder 612 provides the decoded data to the output device 624 for use by the client. The output device 624 may be any suitable device, such as a television, a computer, any suitable display monitor, a VCR, or the like.

The graphics overlay module 614 enhances the displayed graphics quality, for example by providing alpha blending or picture-in-picture performance. In an exemplary embodiment, the graphics overlay module 614 may be used for graphics acceleration during game play mode, for example when a service provider provides an on-demand game service using the system according to the present invention. .

The user interface 618 enables user control of the STB 600 and may be any suitable device, such as a remote control device, a keyboard, a smartcard, or the like. The communication link 620 provides additional communication connections. It can be coupled to another computer or can be used to perform bidirectional communication. The data bus 622 is preferably a "high speed" data bus suitable and commercially available for performing data communication in a real time manner as required by the present invention. Suitable examples are USB, firewire, and the like.

9 shows a process 700 for receiving a DOD service according to an embodiment of the present invention. The process 700 begins at step 702, where the client selects the desired DOD service from the DOD services available at the DOD server 450 (FIG. 7) using the user interface 618 (FIG. 8). This may include selecting a program for viewing from a list of available DOD programs on the EPG. The service may be selected by entering a code corresponding to the desired service using the user interface. If a DOD service is selected, the process continues to step 704, where the STB retrieves expiration information from the EPG program corresponding to the selected DOD service. In a preferred embodiment, all available DOD services have associated expiration information available through the EPG program. Thereafter, in step 706, the STB adjusts to the appropriate bandwidth and appropriate broadcast data to receive the selected DOD service. In step 707, the STB receives the selected DOD service via the data stream sent by the DOD server 450 (FIG. 7).

In step 708, the STB stores the received DOD service and corresponding expiration information on the internal hard drive 608 (FIG. 8) for future use. Alternatively, the DOD service and corresponding expiration information may be stored on a movable storage medium such as a zip disk or CD re-recording disk. In the other embodiment, the DOD service is stored in a manner accessible only by the mounted STB for reading stored expiration information.

FIG. 10 shows a process of the STB for accessing stored DOD services at 750 according to an embodiment of the present invention. The process begins at step 752, where the user selects the DOD service that was previously stored in the STB of step 708 (FIG. 9) to be accessed using the user interface 618 (FIG. 8). This may include selecting a program for viewing from a menu listing available DOD services stored in the STB, displayed by the user interface.

In step 754, the STB retrieves expiration information corresponding to the selected DOD service from the memory 608. In step 756, the STB 600 (FIG. 8) determines whether the selected DOD service has expired. This determination is made by processor 604 (Fig. 8), which compares the expiration date included in the expiration information with the current date. If the date indicated by the expiration information stored in memory is later than the current date indicated by the EPG program, the process continues to step 758. In step 758, the STB retrieves the DOD service selected for use by the client. In step 759, the STB displays certain graphical elements of the selected DOD service on an A / V monitor or television set.

If the selected stored DOD service has expired, the process proceeds to step 760. In step 760, the STB displays a rejection message to the user. This message may include information such as instructions for re-accessing the expired DOD service.

11 shows a copy protection process 800 according to an embodiment of the present invention. The process begins at step 802, where the user selects the DOD service to be accessed using the user interface 618 (FIG. 8). This may include selecting a program for viewing from a list of available DOD programs on the EPG. The DOD service may be selected by entering a code corresponding to the desired service.

In step 804, the STB retrieves copy protection information corresponding to the DOD service selected from the EPG program. According to one embodiment, each DOD service has associated copy protection information that can be accessed by the STB via the EPG program. In step 806, the STB determines whether copy protection has been applied to the selected DOD service based on the copy protection information. If no copy protection is indicated, the process continues to step 808, where the STB 600 (FIG. 8) receives the selected DOD service from the server 450 (FIG. 7). Thereafter, in step 810, the STB displays certain graphical elements of the selected DOD service to the user via an A / V monitor, VCR, or the like. The display can be freely copied to a videotape or DVD.

According to another embodiment, the associated copy protection information is included in headers 110 (FIG. 1) of the packet stream carrying the selected DOD service. In another embodiment, the STB retrieves copy protection information after receiving the DOD service.

If copy protection is indicated by the copy protection information, the process proceeds to step 812, where the STB receives the selected DOD service from the server. Thereafter, in step 814, the STB applies copy protection to the received DOD service before displaying the selected DOD service. Such copy protection may include the application of various image distortions, random shakes, signal noise or color destabilization. Such methods of modifying video signals to degrade the quality of replication are described by US Pat. No. 5,883,936, entitled VIDEO COPY PROTECTION PROCESS ENHANCEMENT TO INTRODUCE HORIZONTAL AND VERTICAL PICTURE DISTORTIONS, hereby incorporated by reference. At the same time, any other method known to those skilled in the art, which deteriorates the quality of the video signal viewing without degrading the quality of the video signal viewing, may be used as the copy protection method. The copy protection may be applied through the use of dedicated circuitry in the STB 600 (FIG. 8) or the use of software stored in the STB memory 608 (FIG. 8).

Thereafter, the process proceeds to step 816, where the selected DOD service is prevented from being duplicated and displayed in place. This allows the user to normally watch the selected DOD service, but causes certain copies of the DOD service to be visually distorted.

12 shows a process for receiving a DOD service with associated copy protection information, at 830, according to one embodiment of the present invention. The process 830 begins at step 832 where the client selects the desired DOD service from the DOD services available at the DOD server 450 (FIG. 7) using the user interface 618 (FIG. 8). This may include selecting a program for viewing from a list of available DOD programs on the EPG. The service may be selected by entering a code corresponding to the desired service using the user interface. If a DOD service is selected, the process continues to step 834, where the STB retrieves copy protection information from the EPG program corresponding to the selected DOD service. In a preferred embodiment, all available DOD services have associated copy protection information available through the EPG program. Thereafter, in step 836, the STB adjusts to the appropriate bandwidth and the appropriate broadcast data to receive the selected DOD service. In step 838, the STB receives the selected DOD service via a data stream sent by the DOD server 450 (FIG. 7).

In step 840, the STB stores the received DOD service and corresponding copy protection information on an internal hard drive 608 (FIG. 8) for future use. Alternatively, the DOD service and corresponding expiration information may be stored on a moving storage medium such as a straw disc or CD re-recording disc. In the other embodiment, the DOD service is stored in a manner that can only be accessed by a mounted STB to read the stored copy protection information.

FIG. 13 shows in step 840 a copy protection process for previously stored DOD services in step 840 (FIG. 12), according to one embodiment of the invention. The process begins at step 852, where the user selects a DOD service to be accessed from a menu of DOD services stored on the STB's hard drive using the user interface 618 (FIG. 8).

In step 854, the STB retrieves copy protection information corresponding to the selected DOD service from the hard drive 608 of the STB. In step 856, the STB determines whether copy protection has been applied to the selected DOD service based on the copy protection information. If no copy protection is indicated, the process continues to step 858, where the STB 600 (FIG. 8) retrieves the selected DOD service from the hard drive memory of the STB. Thereafter, in step 860, the STB displays certain graphical elements of the selected DOD service to the user via an A / V monitor, VCR, or the like. The display can be freely copied to videotape or DVD.

If copy protection is indicated by copy protection information stored in the STB, corresponding to the selected DOD service, the process proceeds to step 862, where the STB retrieves the stored DOD program from the hard drive. Thereafter, in step 864, the STB applies copy protection to the retrieved DOD service before displaying the selected DOD service. Such copy protection may include the application of various image distortions, arbitrary shake, signal noise or color destabilization as discussed with reference to FIG. 11 above. Simultaneously, any other method known to those skilled in the art that deteriorates the quality of the reproduction of the video signal without degrading the quality of the video signal viewing may be used as the copy protection method. The copy protection may be applied through the use of dedicated circuitry in the STB 600 (FIG. 8) or the use of software stored in the STB memory 608 (FIG. 8).

Thereafter, the process proceeds to step 866, where the selected DOD service is prevented from being duplicated and displayed in place. This allows the user to normally watch the selected DOD service, but certain replicas of the DOD service are visually distorted.

The above examples illustrate certain exemplary embodiments of the invention, from which other embodiments, variants, and modifications will become apparent to those skilled in the art. Therefore, the present invention should not be limited to the specific embodiments described above, but rather defined by the following claims.

Claims (34)

Storing at least one DOD service for future access, providing the at least one DOD service to at least one client; And At least one association corresponding to the at least one DOD service, to the at least one client indicating at least one associated expiration information packet that is no longer accessible to the DOD service afterwards; Providing the expiration information packet Method for providing on-demand data (DOD) services comprising a. 2. The method of claim 1, wherein the at least one associated expiration information packet is provided to the at least one client via a transmission medium. 2. The method of claim 1 wherein the at least one associated expiration information packet is stored. 4. The at least one associated expiration of claim 3, wherein the at least one DOD service is configured such that the stored at least one DOD service and the at least one associated expiration information packet can be accessed by the at least one client. And stored with the information packet. The at least one DOD receiver of claim 1, wherein the at least one DOD service is stored in at least one DOD receiver for future access by the at least one client. Operating to access a service. 6. The method of claim 5, wherein the DOD receiver is operative to deny access to the stored at least one DOD service if the first set time is exceeded. The at least one corresponding to the at least one DOD service of claim 1, wherein the at least one associated copy protection information packet indicates a second set time, at which replication of the at least one DOD service is subsequently stopped. Providing one associated copy protection information packet. 8. The method of claim 7, wherein the at least one DOD service and the at least one associated copy protection information packet are stored in a DOD receiver operative to access the stored at least one DOD service. 10. The method of claim 8, wherein if the second set time is exceeded, the DOD receiver operates to prevent duplication of the stored at least one DOD service. 10. The method of claim 9, wherein the DOD receiver is operative to access the at least one DOD service, and further, selectively operates to selectively stop replication of the at least one DOD service. Receive at least one DOD service, The at least one expiration information packet includes at least one associated expiration information packet corresponding to the at least one DOD service, indicating a first set time, which is no longer accessible to the at least one DOD service. Receiving; And Storing at least a portion of the at least one DOD service in a memory location And selectively preventing access by the client to on-demand data (DOD) services. 12. The method of claim 11, wherein said at least one associated expiration information packet is received from an electronic program announcement. 12. The method of claim 11, wherein storing at least a portion of the at least one DOD service comprises: operating an internal storage medium, the set-top-box (STB) operative to access at least a portion of the DOD service stored on the internal storage medium. Storing the at least a portion of the at least one DOD service in a provided STB. 12. The method of claim 11, wherein the at least one DOD service is received via a transmission medium. The at least one corresponding to the at least one DOD service according to claim 11, wherein the at least one copy protection information packet indicates a second set time, at which duplication of the at least one DOD service is stopped. Receiving an associated copy protection information packet. 16. The method of claim 15, wherein the received at least one associated copy protection information packet is stored. 12. The at least one of claim 11, wherein at least a portion of the at least one DOD service is stored in a DOD receiver operative to degrade the replication of the at least one DOD service in response to the copy protection information packet. Receiving at least one associated copy protection information packet corresponding to the DOD service. 12. The method of claim 11, wherein storing at least a portion of the at least one DOD service at a memory location comprises: accessing the stored portion of the at least one DOD service by the DOD receiver in response to the expiration information packet. Storing at least a portion of the at least one DOD service in a DOD receiver including the memory location, operative to prevent the error. 19. The method of claim 18, wherein the DOD receiver is a set-top-box (STB). 19. The method of claim 18, wherein the DOD receiver comprises a visual display device operative to display at least a portion of the at least one DOD service. Operate to provide at least one DOD program to at least one DOD receiver via a transmission medium, such that the at least one DOD receiver can restrict access to the DOD program where the at least one DOD program has expired A DOD server further operable to provide at least one associated expiration information packet corresponding to the at least one DOD program On-demand data (DOD) broadcasting system for providing DOD programs that can be accessed only for a limited time period to clients. 22. The DOD broadcast system of claim 21, wherein the at least one associated expiration information packet is provided to the at least one DOD receiver via the transmission medium. 23. The system of claim 22, wherein said transmission medium comprises electromagnetic signals of a general range of radio and television broadcasts. 23. The system of claim 22 wherein the transmission medium comprises an optical fiber network. The at least one DOD server of claim 21, wherein the at least one associated copy protection information packet indicates a setup time for which replication of the at least one DOD service may be limited. And further provide the at least one associated copy protection information packet corresponding to the DOD program of the at least one DOD receiver. 22. The DOD broadcasting system of claim 21, wherein the transmission medium comprises the Internet. 22. The system of claim 21 wherein the at least one DOD receiver is operative to restrict access to the at least one DOD program in response to the at least one associated expiration information packet. 28. The system of claim 27, wherein said at least one DOD receiver is further operative to degrade the quality of replication of said at least one DOD program in response to said at least one copy protection information packet. 27. The DOD broadcast system of claim 25, wherein the at least one DOD receiver is a set-top-box (STB). 27. The system of claim 25, wherein the DOD receiver comprises a visual display device operative to display at least a portion of the at least one DOD service. Data bus; A first communication device suitable for coupling to a communication medium for digital broadcast, the digital broadcast data including at least one DOD service, the first communication device operable to receive digital broadcast data; a) reading at least a portion of said digital broadcast data comprising expiration information associated with said DOD service; b) determining whether the received DOD service has expired based on the expiration information; And c) preventing access to the DOD service if the DOD service has expired; A memory bidirectionally coupled to the data bus, the computer comprising instructions executable for the memory bus; A digital data decoder coupled in both directions to the data bus; A centrally bidirectional coupling to the data bus controlling the memory, the first communication device and the digital decoder, operable to process digital data received at the first communication device, and executing an STB control process Processing Unit (CPU) Set-top-box (STB) for receiving on-demand data, comprising. 32. The STB of claim 31 wherein the memory comprises temporary random access memory (RAM) and persistent storage, wherein the computer executable instructions are stored in the persistent storage. 33. The STB of claim 32 wherein the persistent storage device is a hard disk. 32. The STB of claim 31, wherein the digital broadcast data further includes copy protection information.