TV receiver using cable card for abstracting open cable application platform (OCAP) messages to and from the head end

A TV receiver such as a set-top box has an Open Cable Application Platform (OCAP) programming interface that communicates with interactive digital video applications such as pay-per-view applications to enable a viewer to communicate requests, purchase orders, and the like to a head end. A cable card provides both decryption of incoming video from the head end as well as translation functionality that transforms standardized messages into a proprietary protocol recognizable to the head end. The OCAP has an API that interfaces with the application and that directs standardized messages from the application to the standardized interface of the removable cable card ensuring common reliance on the translation functionality built in to the cable card.

FIELD OF THE INVENTION

The present invention relates generally to TV receivers that use removable cable cards for conditional access (CA).

BACKGROUND OF THE INVENTION

Removable cable cards, which provide proprietary decryption functionality for received TV audio and video, have been provided to enable consumers to purchase TV receivers such as set-top boxes in one cable provider area, then use them in another cable provider area should the consumer move there or otherwise wish to use the receiver there. In essence, instead of having to buy an entire new set-top box when a consumer moves from one cable provider area to another, which otherwise is necessary to be able to decrypt TV programming using the typically proprietary encryption scheme of the cable provider, the user need only acquire a new and relatively less expensive cable card. Thus, cable cards are removably engageable with TV receivers to provide the necessary decryption functionality, and each cable provider can lease cable cards with its own proprietary encryption scheme to consumers who move into that provider's area. The remainder of the set-top box or other TV receiver advantageously remains useful in all cable provider areas because the remaining components of the receiver typically are not proprietary.

Recent trends have provided receivers that support not just conventional one-way communication from the TV signal head end to the receiver, but also two-way communication, to support so-called “interactive digital video”. Examples of interactive digital video include pay-per-view, in which a TV receiver user can input certain requests and commands, as well as purchase orders, for pay-per-view programming using the TV receiver, and video-on-demand, entailing many of the same communication considerations. Also, so-called “switched digital” can be implemented using two-way TV receivers. Switched digital in essence allows all the viewers in a particular area to in essence report back to the head end what channel they are viewing, so that, for instance, the head end may take intelligent steps with respect to bandwidth such as ceasing transmission into the area of a channel that is not currently being viewed by anyone in the area and thereby releasing bandwidth for other uses.

Partly to support such two-way interactive digital video, the Open Cable Application Platform (OCAP) has been introduced. In effect, OCAP defines an application platform interface implemented by the TV receiver platform which allows software applications, downloaded to the receiver, to communicate with the receiver through a common standard interface and exploit its functionality. In turn, the OCAP interface communicates through the receiver's communication port with the TV signal head end. In this way, for example, viewer purchases of video-on-demand may be facilitated, with the purchased video then transmitted from the head end to the receiver, to be decrypted by the cable card of the receiver and then displayed on the TV screen.

As understood herein, the use of OCAP can entail rather expensive hardware requirements, and some consumers may not desire the added OCAP functionality and instead prefer a less expensive receiver. As also understood herein, in such receivers it would be desirable to allow third parties to provide applications that do not rely on OCAP, to support certain functionalities such as certain graphical user interfaces for the TV including cross-media bars, etc.

The present invention further recognizes, however, that each cable provider, in addition to implementing its own proprietary encryption scheme, also typically employs a proprietary application protocol from the TV receiver back to the head end. With this understanding in mind, the present invention recognizes that the cable card may have further use, in addition to decrypting incoming video, in also transforming outgoing messages from the third party applications in the receiver (which do not necessarily know the cable provider's proprietary application protocol to the head end) into messages that are understandable by the head end.

SUMMARY OF THE INVENTION

Accordingly, while such functionality in the cable card is desirable, the present invention makes the following critical observation. If OCAP and/or its applications are programmed to know the proprietary application protocol of the cable provider and, hence, to bypass the transformation capability in the cable card, those applications will fail to work across multiple networks and the efficacy of the transformation capability in the cable card, which recall is provided by the cable provider whose OCAP-based applications might not otherwise require it, is not stresses and cannot be guaranteed. In other words, the present invention critically recognizes that to ensure the proper working of the transformation capability in the cable card, all applications, both OCAP and non-OCAP, should commonly rely on the capability.

With the above in mind, a TV receiver such as a set-top box or TV has a receptacle that removably receives a cable card. The cable card has a decryption capability. A computer-readable medium that can be used by a processor is also provided, and the medium bears a first application which provides a first functionality including an interactive digital video functionality that permits a user to send messages from the receiver to a TV signal head end. A first programming interface communicates with the first application. As set forth further below, the first programming interface is configured to send messages from the first application to the cable card for transformation thereof into a predetermined proprietary protocol understandable by the head end.

In some implementations a third party application providing a second functionality also transmits messages to the cable card without sending the messages through the programming interface. The kernel of the programming interface can be the Open Cable Application Platform (OCAP), with the added features disclosed herein. More particularly, the OCAP includes a first application programming interface (API) that is configured for communicating with the first application, which may be, e.g., an interactive pay per view (IPPV) application. If desired, the OCAP can include second and third APIs configured for communicating with respective second and third applications. The second application can be a video on demand (VOD) application, with the third API being a switched digital application.

In another aspect, a computer readable medium is disclosed that can be used by a digital processor. The medium bears an Open Cable Application Platform (OCAP) programming interface which includes a first application programming interface (API) configured for communicating with a first application. The first application has an interactive digital video functionality. The first API is configured to send messages from the first application to a removable cable card for abstracting information in the messages. The cable card also has a video decryption capability.

In still another aspect, a method includes providing a cable card that is removably engageable with a TV receiver for decrypting video from a head end and providing decrypted video to the receiver for display thereof. The cable card also transforms standardized messages to/from applications associated with the receiver into the proprietary protocol usable by the head end. A first application is also provided, with the first application providing a first functionality including an interactive digital video functionality. A first programming interface communicates with the first application. The first programming interface is configured to send messages from the first application to the cable card for transformation thereof into the application protocol usable by the head end.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring initially toFIG. 1, a system is shown, generally designated10, which includes a television12receiving, via a set-top box (STB)14, audio video TV programming from a head end16, such as a cable or satellite head end, over a wired or wireless link17. The STB14and TV12are examples of receivers. Other examples include set-back boxes. While the STB14is shown separately housed from the chassis18of the TV12, it is to be understood that the functionality of the STB14may be incorporated into the chassis18.

As shown, the STB14includes a STB processor20and a computer readable medium22such as volatile or non-volatile solid state storage, disk storage, tape storage, or other type of electronic storage medium or logic circuitry that typically can be executed by the processor20. The STB14is also formed with a receptacle24for removably receiving a cable card26. It is to be understood that whileFIG. 1shows a removable cable card, the term “cable card” also includes chips that are intended to be permanently mounted in a component such as a STB with only the software contained on the chip being “removable”.

Moreover, while the element26is referred to herein as a “cable card”, it is to be understood that present principles apply not only to cable TV systems but also to satellite systems and other TV systems. Accordingly, “cable card” means a removable or non-removable module that undertakes both decryption of audio video content as well as translation for the purpose of abstracting messages to/from the applications discussed below into a protocol that is understood by the head end16. To this end, the cable card26may have its own internal processor28and electronic storage medium30. Likewise, the head end16typically includes one or more head end processors32and computer readable media34. In some implementations the cable card may be established by two modules, one for decryption and one for protocol translation.

Additionally, as shown the TV12typically includes a TV processor36and data storage medium38. The TV12may also include a TV receptacle40for removably receiving the cable card26in the event that no STB is provided. Once the cable card26decrypts audio video from the head end16using a typically proprietary decryption algorithm and keys, the video may be presented on a display42of the TV12, e.g., a flat panel matrix display, cathode ray tube, or other appropriate video display.

It is to be understood that the software architecture shown inFIG. 2and the logic shown inFIG. 3is implemented on one or more of the TV12, and/or STB14, and/or other TV receiver, for cooperation with the cable card26.

Turning now toFIG. 2, as shown an interface such as an open cable application platform (OCAP) interface is provided. The interface44may be implemented on the STB memory22for execution by the STB processor20. Or, the interface44may be implemented elsewhere, e.g., on the TV storage38for execution by the TV processor36. A non-limiting example OCAP specification without the below-described APIs is available at www.openeable.com.

In accordance with present principles, the present inventive aspect provides one or more application programming interfaces (API) to the OCAP interface44. In the embodiment shown, first through third API46,48,50are shown, for communicating with respective OCAP applications52,54,56for purposes to be shortly disclosed. The OCAP applications may be interactive digital video applications. Accordingly, the first application52may be an interactive pay-per-view (IPPV) application that can be invoked by a user to, e.g., browse, select, and pay for pay-per-view programs from the head end16. The second application54may be a video on demand (VOD) application that enables viewers to, e.g., browse, select, and pay for VOD programs from the head end16, typically with trick play features such as fast forward, pause, rewind, etc. On the other hand, the third application56may be a switched digital application to function in accordance with switched digital principles discussed above.

Accordingly, each API46,48,50is tailored to communicate with one or more respective applications, typically interactive video applications, and to send messages to/from the application to a transformer function58in the cable card26. The transformer function transforms or otherwise renders the standardized messages it receives into an application protocol, typically proprietary, that is recognized by the head end16. The cable card26then forwards the proprietary messages through a modem60in, e.g., the STB14to the head end. In response, the head end16may provide proprietary messages and signals including audio video streams back through a TV tuner62in, e.g., the STB14. These proprietary messages may be transformed into standardized messages and these messages may be decrypted by a decrypt function64of the cable card26, typically proprietary to the same cable company as is the transform function58. Decrypted audio video signals are sent to the TV12where video may be displayed on the display42and audio played over TV speakers. The standardized responses may be forwarded to the applications.

Additionally, one or more non-OCAP third party applications66such as user interface applications and the like may be provided in the STB14and/or TV12and may also communicate with the head end16to receive, e.g., electronic program guide (EPG) information. Like the OCAP applications52-56, the non-OCAP application66can communicate with the head end16by virtue of sending its messages through the transform function58of the cable card26, even though the head end may recognize a protocol unknown to the non-OCAP application66.

It may now be appreciated that the APIs46-50facilitate the execution of the functions of the respective underlying applications52-56. In the case of, e.g., IPPV, these functions include, by way of example only, allowing the user to obtain price options from the head end, select a video display format, select a human language in which the program is desired, select a video quality, obtain a receipt from the head end should a PPV stream be purchased, obtain purchasing history, etc. A non-limiting example IPPV API46is appended to the end of this specification.

FIG. 3illustrates the high level logic provided by one of the OCAP APIs discussed above, as well as logic performed by the cable card. Commencing at block70, the OCAP API passes control to block72, wherein messages such as commands, calls, etc. are received from the respective OCAP application. The messages are processed as appropriate and diverted at block74to the transformer function58of the cable card26.

Block76represents that at the cable card26, the messages are transformed to the typically proprietary application protocol recognized by the head end16. This transformation may be regarded as an abstraction of the calls from the OCAP application into a format suitable for the head end16. The messages are then sent through the modem60to the head end16at block78.

FIG. 4shows a detailed architecture that can be implemented in a set-top box, set-back box, or even in a TV chassis. InFIG. 4, an OCAP implementation100includes an IPPV translator102communicating with one or more OCAP applications104through an OCAP IPPV interface106of an OCAP interface block108. Other OCAP applications110can also be provided. The function of the IPPV translator102and OCAP IPPV interface106is to cooperate to intercept the standardized messages from the IPPV application104divert the messages to the protocol transformer or translator function116of a cable card118.

Thus as shown, the IPPV translator102of the OCAP implementation100can communicate, through a standardized cable card IPPV interface112of a cable card interface114, with a message translator such as the IPPV translator116of the cable card implementation118, which is a translator function of the cable card that is in addition to the mere video decryption function. In turn, the IPPV translator116of the cable card implementation118can communicate with a head-end IPPV120through a proprietary head-end IPPV interface122of a head-end interface124as shown. Also, as shown inFIG. 4the IPPV translator116of the cable card implementation118can communicate with a resident (non-OCAP) IPPV application126through the cable card IPPV interface112.

Thus, in the architecture ofFIG. 4, the IPPV translator is provided for the OCAP implementation and the OCAP IPPV interface is provided for the OCAP interface, such that the OCAP IPPV application does not communicate directly with the head-end IPPV except through a IPPV message translator of the cable card using the IPPV translator102and OCAP IPPV interface106as shown.

While the particular TV RECEIVER USING CABLE CARD FOR ABSTRACTING OPEN CABLE APPLICATION PLATFORM (OCAP) MESSAGES TO AND FROM THE HEAD END is herein shown and described in detail, it is to be understood that the subject matter which is encompassed by the present invention is limited only by the claims.