Interactive information delivery system

What is claimed is:

1. An information delivery system for delivery of audio, video, and user data through a communication medium from a head end to a user end, the user end including a display device, the communication medium having a plurality of transmission channels, said channels carrying a variety of broadcast programming information on ones of said plurality of transmission channels, comprising:

a server node having means for broadcasting a data stream on a subset of said transmission channels, the data stream comprising a plurality of compressed data objects, each data object comprising at least one media object, each media object comprising a still image, a motion video image, an audio clip, or text in encoded form, the data objects further including broadcast programming content information and instruction code, directing the placement of the data and media objects on the display device to provide a broadcast programming information program guide, the data stream being substantially repeated at regular intervals in multiplexed fashion over the communication medium;

a client node coupled to the display device, the client node having means for receiving the data stream, for decompressing at least selected portions of the stream, and for producing a user-detectable output on the display device in response to the data stream.

2. The information delivery system of claim 1 wherein the system includes backchannel communication, and the client node communicates with the server node via the backchannel communication to process information requests from a viewer.

3. The information delivery system of claim 1 wherein the means for broadcasting includes means for broadcasting a plurality of data steams in a multiplexed fashion; and the means for receiving including means for producing a user-detectable output in a user-selectable subset of the plurality of data streams.

4. The information delivery system of claim 1 further including a user interface, a portion of the user interface being resident in the client node and a portion of the user interface being provided in at least one of the data objects.

5. The information delivery system as defined in claim 1 wherein the data stream is transmitted via the level two transport layer of the MPEG 2 transport standard.

6. The information delivery system as defined in claim 1 wherein a portion of the user interface is resident in the client note.

7. An information delivery system for use with a communication medium having a plurality of transmission channels, said channels carrying a variety of broadcast programming content on ones of said plurality of transmission channels from a head end to a user end, the user end including at least one display device, comprising:

a server node having means for broadcasting a plurality of data streams on a subset of said transmission channels in multiplexed fashion over the communication medium, each data stream being comprised of a plurality of compressed data and media objects in encoded form, each media object comprising a still image, a motion video image, an audio clip, or text in encoded form, the data objects including broadcast programming content information and instruction code directing the placement of the media objects on the display device to generate a user interface, including said content information, at least a majority of data stream being repeated at regular intervals, the data stream being formatted so that each object has a maximum latency;

at least one distribution node; and

a plurality of client nodes coupled to the transmission channels at the user end each having means for receiving the data streams, for decompressing the streams, and for producing a user-detectable output in response to each data stream in a user-selectable subset of the plurality of data streams on at least one display device, and means for maintaining said user interface for said maximum latency.

8. The information delivery system of claim 7 wherein the data stream further includes boot instructions to the client node.

9. The information delivery system of claim 7 wherein said user interface comprises a program guide containing information on programming and services available on the information delivery system.

10. The information delivery system of claim 9 wherein the broadcast programming content information is updated prior to broadcast in the data stream.

11. The information delivery system as defined in claim 7 further including back communication between the user interface and the server node.

12. The information delivery system is defined in claim 7 wherein a portion of the user interface is resident in each said client node.

13. An information distribution system coupled to a transmission medium having a plurality of transmission channels, the transmission system carrying broadcast programming from a variety of broadcast sources to a user end, the user end including a display device, comprising:

a head end server broadcasting at least one compressed data stream on at least one of said transmission channels, the data stream including a plurality of media objects comprising a still image, a motion video image, an audio clip, text in encoded form or broadcast programming content information, and programming code directing the placement of the media object on the display device to generate a program guide, wherein the data stream is substantially repeated at regular intervals; and

an end user terminal coupled to the head end server via said transmission medium and including means for receiving the data stream, means for displaying the objects on the display device, means for decompressing the data stream, and selectively interacting with the data stream to remove media objects and to display the media objects to the user display in response to user input.

14. The information delivery system of claim 13 wherein the data stream is broadcast via the level 2 transport layer of the MPEG-2 transport standard.

15. The information delivery system of claim 13 wherein the head end broadcasts a plurality of data streams, each data stream including a plurality of media objects and comprising a digital time multiplexed signal.

16. The information distribution system of claim 13 wherein the distribution system further includes:

at least one repeater node coupled between the head end and the end user terminal;

a client interface unit including

means for decoding the data stream, and for producing a user detectible output in response to a user request to output a specific media object by decoding a subset of each of the data streams.

17. An information delivery system coupled to a transmission medium having a plurality of transmission channels, the transmission system carrying broadcast programming content from at least a broadcast television interface and at least one information service provider to a user end, the user end including a display device, including:

a head end broadcasting a data stream of compressed media objects comprising a still image, a motion video image, an audio clip, or text in encoded form, and programming code directing the placement of the media object on the display device, [in encoded form,] on at least one of said transmission channels, the head end including an encoding means for encoding information in the media objects into an encoded form;

wherein

the data stream further includes a programming guide built from said media objects and containing programming information of content of the broadcast programming or the information service provider; and

the user terminal is coupled to the head-end and receiving the media objects, the user terminal having an output and including decompression means and decoding means for decoding information in the media objects; and

a user interface, at least partially stored in the user-terminal, the user interface including means for selecting a user-defined subset of media objects for provision to the output of the user terminal.

18. An information navigation system for an information delivery system, the information delivery system including a head end and a user end coupled by a transmission medium having a plurality of channels, the head end including a source of audio/visual programming transmitted on a first subset of said plurality of channels, comprising:

an electronic program guide, the electronic program guide comprising a content listing of the audio/visual programming available on the information delivery system;

a user interface, at least partially provided in the user end; and

a service navigator, the user interface interacting with the service navigator and the electronic program guide,

wherein the electronic program guide and user interface are transmitted to the user end in a data stream on a second subset of said plurality of channels, the data stream being comprised of a substantially repeating compressed stream of data objects including said content listing, motion video, audio, text and programming code directing the assembly of the user interface, and is responsive to user input.

19. An information delivery system for use with a communications network including a plurality of channels which provide broadcast program information, comprising:

a server providing a data stream comprising a plurality of compressed data objects, each data object comprising at least a plurality of media objects, each media object comprising a still image, a motion video image, an audio clip, or text in compressed form, and including at least one data object comprising programming content information, the data stream being repeated at regular intervals in multiplexed fashion over the communications network;

a user terminal and display device, coupled to the server via the communications network;

a programming guide containing information on services available on the information delivery system, the programming guide being built from said data objects provided in the data stream;

a user interface, at least a portion of which is provided in and built by the user terminal from the data objects in the data stream;

a service navigation system, interacting with the user interface and the programming guide, to record user preferences; and

an interactive mechanism coupled to the user terminal for accessing, the programming guide, and user interface.

20. The user interface of claim 19 further including a broadcast television interface.

21. The user interface of claim 19 wherein the service navigation system further includes a user customizable selection guide which records user selections over a period of time and displays the selections when prompted by the user.

22. The user interface of claim 19 wherein the media objects are provided to the interface to change interactive components on the interface.

Description Submit all comments and votes

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to the delivery, selection and communication of information in an interactive format, and specifically to the delivery and selection of information delivered to a television user over a cable television system.

2. Description of the Related Art

Television has traditionally been a broadcast medium of entertainment. Service providers, such as television stations and networks, broadcast entertainment and information programming via a communications medium, such as a television network or cable system from the head-end of the communications system to a client or individual user at the receiving end of the system. While in the early days of television, this meant transmission of the broadcast signals through the air, more recently, cable networks have become commonplace. Transmission of the broadcast signals through the cable network provides a much wider signal transmission bandwidth and opens the possibility for the transmission of data in large quantities to the user. Bandwidth is defined as the information capacity of a particular transmission system. This traditional model of one-way communication between the service provider and the user has recently begun to change with the proliferation of interactive communication between the client and the service provider.

The television and cable network communication medium is a particularly advantageous way to transmit a great volume of information from the service providers to the end users, the viewers, and to provide an interactive mechanism for the viewer to utilize services such as video on demand, home shopping, interactive games, and home banking using the television as the interface. However, using television as the mechanism for correspondence between the service provider and the end user requires extensive modification of existing communication hardware to provide one or more of the following: greater signal bandwidth, more powerful head-end servers, and more powerful end-user receivers.

As shown in FIG. 1, a typical cable television system comprises four main elements: the head-end 10, a central originating point of all signals carried, where signals are received from service providers (television networks, special channels, etc.) in process; a trunk system 12, the main artery carrying signals through a community; a distribution system (including trunk bridging amplifiers 14), which is bridged from the trunk system and carries signals to individual neighborhoods for distribution to subscribers; and subscriber drops 16, including individual lines 18 to subscribers' television sets fed from taps (Area 1, Area 2 . . . Area X) in the distribution system. The head-end may include a satellite antenna system, tape processing, live programming cameras, signal-processing equipment, pilot carrier generators, combining networks, and equipment for bi-directional interactive services. The subscriber equipment may comprise end-user terminals, converters, de-scramblers, teletext decoding equipment, and the like, depending on the particular service in place and the sophistication in bandwidth of the given system. The trunk system may be physically composed of open air broadcasts, fiber optic lines, coaxial lines, or a combination of each.

In addition to providing video and music programming, in an interactive system, a significant quantity of information must be transmitted to the viewer as part of the interactive service environment. For example, the interactive environment may include several different interface screens utilizing a "multi-media" format (combining several different types of data, video, and audio), and a pointer or other means (such as a control pad-controlled cursor) for interacting with each of the data, audio, and video elements on the interface screen. As yet, no standard transmission or interaction format for the distribution system has been settled upon, and a number of standards are currently under development by television, telephone, or other communications providers.

A number of commercial services currently exist which provide broadcast programming along with data to a home viewer. Perhaps the most basic of these is commonly referred to as "Teletext," and provides cyclical digital data inserted in the vertical blanking interval of a video signal. (The vertical blanking interval is a standard interspersed period in a video signal which is approximately the black level of the signal, used to accommodate retrace periods of display scanning.) The amount of data which may be supported and transmitted by the Teletext system is limited by the bandwidth of the vertical blanking interval. As such, the data capacity is limited and the net result is usually the provision of this format of a few lines of text at the base of a television screen in the user's home. Teletext services can provide a viewer with a wide variety of useful information which can be program oriented, or completely independent of the program. The viewer uses a remote control key pad to select television images, teletext pages, or a combination of both. Some forms of two-way teletext exist, but these systems usually include an entry keyboard and a return link, via a telephone line, to a database.

A second commercial service to provide data over television transmissions is known as the "Sega Channel." The objective of the Sega Channel is to allow users of the Sega video game system to download software games directly from a broadcast channel for use on the game system rather than requiring the individual user to go to a retail store to purchase game cartridges. The Sega Channel broadcasts game program data on a standard cable channel via a cable network, in a continuous data stream of software games which the user may desire to download. Each game is broadcast at a different time, and broadcast information includes game identification information which is decoded by the game system in the user's home and which identifies the game to the system for downloading. The game system shows the individual user a selection menu on the user's television from which the user can select the particular game he or she wishes to download. When the game is transmitted over the broadcast medium at the appointed broadcast time, the game will be downloaded into the game system and the user may then play the game in the game unit. The Sega channel transmission scheme does not include any provision for "backchannel" information from the user to the information service provider.

Another commercial broadcast system which does provide some backchannel communication, but is limited to smaller broadcast environments, is commercially known as "Spectravision." Spectravision is generally set up in small environments such as hotels, resorts, or other limited areas, and the viewer is provided with one or more screens of information for video on demand, and hotel services such as in-room checkout, room service, and billing queries. The user, through an end-user box and accompanying remote control interface, can request in-room movies through the video on demand interface, request account information, or perform a check out, all through the Spectravision interface. Information which must be transmitted to the user in this system includes the complete video on demand menu (several screens of data), customer services menus and summaries of account information on the customer's charges during the stay in the hotel, and menus which the consumer may scroll through on demand and select to perform such services. This usually represents a fair amount of textual information, however, the backchannel communication for such a system is minimal, thereby limiting user response and choice. A local server for the particular small area which Spectravision services is all that is required. Spectravision also provides the viewer with the ability to switch between dedicated Spectravision services and regular full broadcast television services.

In providing interactive services in larger cable network applications, the main problem which arises is that of server and communications overhead. Allowing each subscriber to browse and navigate through all available services, (such as an electronic program guide for video-on-demand services,) creates substantial processing overhead on the head-end server. This, in turn, requires that the speed and capacity of the head-end server be increased for the system as a whole to be commercially effective, which increases the cost of the system.

As shown in FIG. 2, an interactive delivery system requires a physical delivery system which provides backchannel communication. An attempt to provide a fully interactive television interface on a larger scale will be made by U.S. West, Inc., a telecommunications company, which will conduct a trial of an interactive system in Omaha, Nebr. In the U.S. West example, the network configuration will comprise a broad-band network to provide video and data services. The broadband network is comprised of a head-end broadcasting server 20 providing transmission to a plurality of video switches 24 and nodes 26. The video switch will transmit packets of data continuously or in bursts through the broad-band network. The video switch 24 will deliver signals to a node 26 that will serve from 200 to 2,000 homes. From the video node, dual co-axial cables A,B will be used for distributing video signals to a pedestal that will contain video distribution equipment, video interaction equipment, and an optical network unit. As shown in FIG. 3B, the video portion of the network is a dual co-axial cable design, with a sub-split design "A" cable providing 650 mhz of bandwidth to support 77 analog channels, up to 136 digital channels, and 25 mhz of shared upstream (or backchannel) capacity. The spectrum "B" cable provides 500 mhz of bandwidth to support up to 664 digital channels and 107 mhz of shared backchannel capacity. The split design allows for channel frequency compatibility of the analog channels with existing cable-ready TV sets, while the "B" channel provides backchannel capacity anticipated for the more interactive services expected to use digital channels. A spectrum of the transmission bandwidth of approximately 1 GHz is shown in FIG. 3A. This U.S. West embodiment illustrates how the aforementioned problems will result. The communications overhead on the head-end which will result from backchannel communications and viewer demand, even in the limited service area of the experiment, is quite significant.

When a user is browsing or merely viewing the possible selections available from the head-end, communication with the head-end server is required; however, no revenue for the service provider is created during the browsing events. Thus, activities such as browsing increase the cost for all revenue-generating activity. It would therefore be desirable to reduce the load on the head-end server which is required for any such non-revenue generating activity.

In the aforementioned prior art transmission schemes, the bandwidth allocated from the head-end to the home user is quite large in comparison to the backchannel band-width allocated for viewer communication to the server. Because the total amount of bandwidth through the backchannel which will be required at the head-end at any given time will fluctuate with the use pattern of the subscribers (the number of subscribers making demands on the head end at a given time and the activities of those subscribers), such fluctuation will place unpredictable communication latencies on the system. It is important to determine all communication latencies on the backchannel to determine operating parameters for a commercially viable system and for service providers to configure their programming so that the user is not unduly burdened during the periods of maximum latency in the system.

Additional processing overhead is required during handshaking. Handshaking comprises the interaction with all communications to the server involving a response mechanism to the user which ensures reliable communications between the server and the user. A simplified communications model that does not require, or at least minimize, server intervention in handshaking is desirable.

Congestion within the communications pipeline resulting from large bursts of backchannel communication can impair the quality of service to viewers by resulting in a large latency period. A large volume of backchannel communication or a "connection storm" can occur when large numbers of viewers simultaneously request service, as at the start or end of a popular event, or after a power outage when the users are attempting to re-establish service. This again can result in unpredictable latency times.

Each server has a finite bandwidth, and congestion will occur at the server as the number of requests it must handle increases. Indeed, in large scale implementations, a network of servers will be required to distribute requests and balance the load on the network infrastructure, also increasing the expense of providing service to users.

Any one or more of the aforementioned difficulties could result in the interactive viewing experience being less seamless than the viewer currently experiences with analog television signals. For any system which utilizes digital communication technology to transmit data to a viewer to be commercially viable, the system must make the viewing experience appear as seamless as the viewer's current viewing experience. Viewers have come to expect a minimum level of broadcast quality in television viewing, thereby requiring any new system be comparable to current systems in the manner in which programming and information is presented to the viewer.

Thus, it is desirable to provide an interactive system which will overcome the aforesaid deficiencies in a broadcast communications medium.

One means of disseminating a large amount of data over a network and is the "Data Cycle" proposal and research set forth by Bellcore (Bell Communications Research, Inc.). The data cycle is a proposal for a distributed, shared memory database implemented through use of a storage pump which continuously broadcasts the entire contents of the database over a ring network to a series of access managers which control, for example, SQL-type application access to the data which is broadcast on the network. In the embodiments described in a paper entitled "The Datacycle Architecture: A Database Broadcast System", authors Bowen, et al., a data rate of 52 megabytes per second is supported such that a 32 megabyte database stored on a single storage pump is entirely broadcast every 0.6 seconds. A user seeking to extract data from the database initiates a query through an access manager via one of any suitable number of applications. The access manager then extracts the data and provides it to the application and ultimately the user. The database is continually broadcast over the broadcast channel at a repeating rate, and therefore may be updated via an update manager coupled to the access managers and the storage pump.

As described in the Bowen, et al. paper, the system is useful, for example, in providing a directory assistance database which may be continually updated and provided to the directory assistance operators of a given telephone network.

In consideration of the aforesaid problems, a communications system which reduces the overall overhead at the head-end and still provides complete interactivity and a large quantity of information to the user is therefore desirable.

SUMMARY OF THE INVENTION

It is therefore an object of the invention to provide an information delivery system for use with a communications medium which reduces the overall overhead of the system and yet provide full interactivity for the end user.

A further object of the invention is to provide an information delivery system which operates independently of the physical network to which it is applied and thus may be used on a variety of different networks.

Yet another object of the invention is to provide an information delivery system which can be utilized on current communications networks in use throughout the country.

A further object of the invention is to provide the aforesaid objects using conventional signal and compression schemes currently in place.

A further object of the invention is to provide a standard user interface which is intuitive to use and based on current viewing habits, which provides a viewer access to the services available on the information system, and which may be updated as new and different service providers broadcast on the system.

These and other objects of the invention are provided in an information delivery system having a number of inventive aspects. A first aspect of the invention comprises an information delivery system. The system includes a head end broadcasting a data stream of media objects, the head end being coupled to a broadcast television interface and at least one information service provider, and including an encoder for encoding information in the media object. A programming guide delineating programming information available on the information delivery system may be provided in one or more media objects in the data stream in an encoded fashion by the encoder. A user terminal is coupled to the head-end and receives the media objects. The user terminal has an output and includes a decoder for decoding information in the media objects. Also provided is a user interface, at least partially stored in the user-terminal, which selects a user-defined subset of media objects for provision to the output of the user terminal.

The system allows the reduction of head-end server overhead and predictable system latencies, and one can customize the data stream for individual purposes, or provide additional data streams in hybrid systems using both digital and analog signals.

A second aspect of the invention comprises an encoding structure for an information delivery system. The structure makes use of a dictionary library containing terms and common phrases of the information to be encoded. A listing array is provided which includes a set of listing offsets to the terms and phrases in the dictionary library, and a plurality of listing vectors provide offsets into the listing array. A sorting vector contains sorted offsets into the listing vector and can be used to perform queries of the encoded material while the material is encoded.

The encoding structure provides an improvement over conventional coding structures by optimizing the encoded data structure for decoding by the end user terminal in the information delivery system, and gives greater compression ratios than found in currently-employed techniques.

In yet a third aspect of the invention, an information navigation system for an information delivery system is provided. The navigation system includes an electronic program guide, the electronic program guide comprising a listing of programming available on the information delivery system. The navigation system also includes a user interface having a plurality of object representations (such as icons) of various functions of the system, and including a broadcast television interface. The navigation system also includes a smart service navigator which interacts with the user interface and the electronic program guide to provide an output to the user.

The information navigation system works in conjunction with the delivery system and the encoding structure to deliver to the user a seamless, realistic, real-time interactive viewing experience, while minimizing such problems as communications overhead, transmission congestion, unpredictable system latencies, and finite server bandwidths. In addition, the navigation system provides information to the transmission and service providers which allows the providers to optimize use of the network and services.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described with respect to the particular embodiments thereof. Other objects, features, and advantages of the invention will become apparent with reference to the specification and drawings in which:

FIG. 1 is a block diagram of a conventional cable television network.

FIG. 2 is a block diagram of a communications medium suitable for use with the information delivery system of the present invention.

FIG. 3A is a diagram of a bi-directional trunk system shown in FIG. 2.

FIG. 3B is a diagram of the subdivision of the bi-directional trunk system shown in FIG. 3A.

FIG. 3C is a diagram of the frequency spectrum of the sub-divided bi-directional trunk system shown in FIG. 3B.

FIG. 4 is a representation of an exemplary interface screen which may be provided by an end-user terminal to a user.

FIG. 5 is a table representing media object type, size and bit requirements.

FIG. 6 is a table representing the type and number of media objects suitable for use in a user interface in accordance with the present invention.

FIG. 7 is a block diagram showing the interaction between the MPEG2 transport layer and a network interface in a user terminal.

FIG. 8 is a table representing the bandwidth and space requirements of the objects shown in FIG. 6.

FIG. 9 is a depiction of the encoding scheme for the electronic program guide of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

The interactive information delivery system of the present invention will be described with reference to FIGS. 2-9. Although the system of the present invention will be described with reference to a particular hardware embodiment, and specifically the network embodiment publicly disclosed for the U.S. West trial for Omaha, Nebr., it should be understood that the invention is not limited to any particular hardware configuration. Indeed, a feature of the invention is that the system is designed to be utilized on any number of different communication hardware schemes which may be currently in existence or hereafter developed.

Generally, the invention utilizes a broadcast streaming approach to information delivery through a conventional television distribution network. Through this approach, full motion video, still images, artwork, music, information and other data can be provided to the end-user and used as an information guide to all information sources available on the network to minimize the problems which attend implementing an interactive television system. A single broadcast data stream of such information is repeated at a pre-determined rate, with a "smart" end-user terminal decoding the data stream, thus providing a pre-determined and consistent latency period. The data stream may be broadcast on a single 6 mhz broadcast channel, available on any number of commercial cable television networks (including the U.S. West embodiment set forth above). It should be noted that the particular transmission provider is not critical to the invention.

A unique advantage of this system is that information provided through this format can comprise information which would be considered non-revenue generating, but overhead intensive on the head end. Thus, the overhead on the head-end is reduced without any loss of information to the user. In addition, one or more data streams may be utilized, with each stream serving a particular service provider's special requirements. Thus, the service provider may customize both the individual objects which the provider contributes to a common stream transmitted by, for example, a cable network operator, or may generate an exclusive stream of its own to provide exclusive information to its own broadcast stream.

The information is provided to the end-user terminal in the form of media objects. A second feature of the invention is the digital compression and de-compression of the data. Through the use of MPEG-2 data transport, the data, text, video, and other signals in the broadcast data stream can be sent through the normal broadcast channel and contain enough information to supply the "smart" terminal with program and service information to make the output at the user-end appear to be completely interactive, allowing the user to interact with the data without placing undue burdens on the head-end of the system. The stress and sophistication of interactivity on the end-user of the system can be dependent on the hardware in use at the user-end of the system. As hereinafter described, by using video modulation, a 6 mhz channel will support a bandwidth of 30 Mbps when modulated at 64 quadrature-amplitude modulation (QAM). This yields an effective bandwidth of 27 Mbps for the delivery of media objects, after accounting for transport level error correction coding.

An additional feature of the invention is a user interface and service navigator which generally comprises two components. A first component will be resident at the user-end, in the end-user terminal, and includes the ability to compensate for transmission system latencies. A second component of the user interface will allow the particular service provider at the head-end to program a variety of situation-based responses for the user interface to enact when any communication latencies occur. The provision of these situation-based responses is possible because of the known values for the maximum latency of the repeating broadcast data stream, which is the maximum latency for the system. An overview for the user interface provides a programming navigation format through which the service provider can implement customized menus particular to the broadcast data stream.

Yet another component of the user-interface allows for the recording and storage of user-preferences based on repeated inquiries to the system.

Through use of the broadcast streaming feature, data compression and the service navigator, the user is provided with a fully interactive experience while the stress on the head-end and communication overhead is limited. Hence, the number of video servers required at the head-end is reduced, while the latency of the system is made predictable. Thus, the system of the present invention provides superior navigation to television viewers as they cope with the great number of choices available to them while reducing the hardware overhead required for system navigation.

Additionally, while using digital media objects transmitted in a compressed format, the user is provided with a seamless viewing experience nearly equivalent to that presently experienced with analog signals. A plurality of such objects may be provided to the end user, thereby increasing the quantity of information that a user is exposed to, while allowing the presentation of such information to be manipulated in a common format and into a highly optimized manner for both the user and service providers. This advantage is provided through the use of a "smart" user end terminal, the user interface, and a "smart" service navigator, as will be hereinafter described. The system of the present invention therefore presents a commercially viable improvement to existing interactive television approaches.

In the transmission system shown in FIG. 2, the head-end server 20 is utilized to encode and transmit a plurality of media objects into the data stream into the trunk system. Each media object conforms to a specific model representing composition of various media types, such as video, still pictures, background artwork, music or text. Using each of the media objects, complicated structures can be built from easy to manipulate and simple to define components. Each media object embodies a broad set of functionality requiring minimal effort to construct useful visual, auditory, and sensory output for the user interface.

Each object can comprise data which is provided to the "smart" terminal to define the information which is to be placed in the user interface and displayed to the user, information for the user interface as to how the object should be depicted by the user interface, any information regarding elements for controlling the object (such as buttons, visual gauges, etc.), and code which controls the behavior of the object in the form of scripts or embedded code contained by the object.

Each media object may comprise, for example, an electronic program guide, a short video clip of a video on demand program, or other information which is designed to be a control mechanism for other objects. In such a delivery system, the communications load on the system relies substantially in the transmission of data and images to the network, thereby minimizing backchannel communication.

FIGS. 3A-3C show a block representation of the bi-directional trunk system in use in the U.S. West trial. As shown in FIG. 3B, the trunk system is divided into a uni-directional, analog "A" cable and a bi-directional, digital "B" cable. As shown in FIG. 3C, each cable includes a number of 6 mhz channels which transport the data utilized in the system of the present invention.

The novel user interface and service navigational scheme of the present invention will be described with reference to FIG. 4. FIG. 4 shows components of the user interface, comprising an overview of an interactive interface screen with various different media objects placed thereon. As shown in FIG. 4, typical media objects represent icons for a "media valet," a TV guide (an electronic program guide), a video on demand guide, and a navigation guide. Standard broadcast television can also be provided in a window with a media object used to overlay the picture with current information about the program.

The user interface is designed to provide viewers with optimum choice, but not to overload the user with too many choices which will drive the user to avoid using the interface because he/she is overwhelmed. The interface is designed to leverage itself off what the viewing public currently experiences--integrating new experiences around viewers' existing experiences. The user interface of the present invention uses the predictable response times of the broadcast data stream to offer interactivity to the services offered by the information providers through a consistent look and feel.

The user interface of the present invention is highly visual. The interface items are depicted by representations of themselves. For example, movies can be represented by poster art, and services can be represented by the service logo. As such, the viewer can instantly comprehend the hierarchy and array of items available.

The interface incorporates graphics, music and transition effects which have a quality similar to or equal that of a television picture. By animating the visual display, the display is never idle when waiting for viewer input. Furthermore, the interface provides a navigation platform that may be utilized across different service providers. A standard paradigm provides a singular visual understanding of the categories and hierarchy of items which are available. In one embodiment, the paradigm comprises an organization wherein one moves vertically on the screen to choose between higher level categories, while one moves horizontally to select within the category. As such, more than one menu can be displayed at a given time, and the viewer is less likely to get caught in layer upon layer of menus.

Furthermore the interface is designed to be expandable, so that as more services become available and more programming is offered, they can be easily added to the interface by adding different media objects to the data stream.

A further unique aspect of the interface is the provision of a smart service navigator or "media valet." Through the use of intelligent filtering and weighting algorithms, the interface can be personalized for each viewer household. The media valet acts to record viewer preferences based upon any number of algorithms which can not only record preferences, but make suggestions to the user for programs which the user may find similar or interesting, based upon the viewers recorded viewing habits. For example, the service navigator may note that the viewer tends to view movies in a particular genre with a particular movie star. When a new listing of a movie which fits a similarity profile becomes available, the valet may suggest this option to the user.

The service navigator may be programmed by the user for specific preferences, however a unique aspect of the invention is the that the navigator make such interpretations without any more user input than that required by the user in selecting programming. Such suggestions by the navigator may be automated so that the navigator provides suggestions each time the system is activated, or the suggestions may be provided by a specific user request.

The navigator may be implemented in a manner currently similar to conventional "agency" software. For example, certain types of searching tools currently available for the internet utilize a vector analysis technique wherein a vector map is