Abstract:
A system and method for providing quality assurance for interactive television and software application data packages delivered via a network. By employing “code checks” that determine “code points” based on the original package, content or data packages may be checked for errors at any later point within the network path from the provider to the subscriber. The data package can be checked for errors by performing some or all of the code checks and comparing the current code point values to the original code point values. If the current values differ from the original values, then the data package has changed and an error is likely to have occurred. Further action may then be taken to determine the nature of the error and to respond to it.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
   This application is a divisional of, and incorporates herein by reference in its entirety, prior application Ser. No. 10/620,964, which was filed on Jul. 15, 2003. 
   This application claims priority to, and incorporates herein by reference in its entirety, U.S. Provisional Application No. 60/396,119, entitled “SYSTEMS AND METHODS FOR PERFORMING QUALITY ASSURANCE ON INTERACTIVE TELEVISION AND SOFTWARE APPLICATION DATA DELIVERED VIA A NETWORK,” which was filed on Jul. 15, 2002. 

   FIELD OF THE INVENTION 
   The present invention is directed to systems and methods for performing quality assurance on interactive television and software application data that is delivered via a network. 
   BACKGROUND OF THE INVENTION 
   Any data which is delivered over a network is vulnerable to having errors introduced into the data. This problem is particularly prevalent in networks with multiple components and especially where no single entity controls all of the network components between the sender and receiver of the data. 
   For example, networks which deliver interactive television have many components which are likely to be geographically remote from one another and are frequently under the control of a multiple entities. An example of this kind of network is one where a content provider (e.g., Home Box Office® (HBO®)) has provided content (e.g., a movie) to an interactive television service provider for delivery to subscribers using a Video-On-Demand (VOD) system where the subscriber selects a movie using a Graphical User Interface (GUI). 
     FIG. 1  shows an example of a network implementing a VOD service. The content provider prepares and delivers a Movies-On-Demand (MOD) data package  100  to an interactive television service provider. The MOD package  100  contains the audio and video for the movie as well as other data that is used to provide at least part of the GUI display that the subscriber views when ordering a movie. 
   The interactive television service provider loads the MOD package into an Asset Management/Business Management system such as the MediaPath™ system by N2Broadband, Inc of Duluth, Ga. The Asset Management Server (AMS)  110  maintains a catalogue of the content (e.g., movies in this case) that is available on the VOD service. The Business Management Server (BMS)  120  handles the business and billing aspects of the VOD service by, for example, applying business rules to perform subscription checking and ensuring that subscribers are properly billed for their use of the service. The audio and video that are to be delivered to the subscriber when a movie is ordered are then stored in one or more VOD servers  140  (e.g., a MediaClusterm by SeaChange International of Maynard, Mass.) that may be located remotely from the AMS  110  and BMS  120  so as to serve geographically diverse subscribers. The interaction over the network between the subscribers and the VOD service is managed by a Digital Storage Management-Command and Control (DSM-CC)  130  data carousel such as the Digital Network Control System (DNCS) by Scientific-Atlanta, Inc. of Lawrenceville, Ga. 
   Each subscriber has a Set Top Box (STB)  160  which connects to the subscriber&#39;s television  170  and connects to the DSM-CC  130 , VOD server  140 , AMS  110 , and BMS  120  via the “cable plant”  150  of the subscriber&#39;s cable provider (which may or may not be the same as the interactive television service provider). This cable plant consists primarily of the various hardware and software components (e.g., network switches, etc) required to provide connectivity between the STB  160  and the VOD service components. The STB  160  may be, for example, a Scientific-Atlanta Explorer 3000® running PowerTV® operating system software and the Prasara user interface application. 
   When a subscriber accesses the VOD service to order a movie, the subscriber is first presented with the GUI, including information from the MOD package  100  as provided by the AMS  110 . The subscriber may then request to order the movie. The request to order the movie is routed through the DSM-CC  130  to the BMS  120  to determine if the subscriber is authorized to order the movie and ensuring that billing for the service is properly handled. Once the BMS  120  authorizes the movie order request, a VOD server  140  streams the movie audio and video to the STB  160  which decodes the data and plays the movie on the subscriber&#39;s TV  170 . 
   There are numerous opportunities at a variety of places in the network for errors to be introduced into the GUI that is displayed to the user, and even the movie data itself. For example, the interactive television service provider may manually load the MOD package  100  into the AMS  120 , possibly editing portions of the GUI data in the process, and errors may be introduced into the data. In another example, errors may be introduced simply through corrupted transmission from one component in the network to another especially when data elements from the same data package are stored on different components in the system. Errors may also be introduced due to inconsistencies between the software in different models of STBs. 
   These errors may be as trivial as a misspelling in the title of the movie or the artwork to be displayed on the GUI may be corrupted. These errors may also be much more serious such as the complete corruption of the movie&#39;s audio or video or the mismatching of different data elements such as misclassification of adults-only material as children&#39;s content. 
   Present quality assurance techniques rely on direct inspection by a human, which is not practical, or on dedicated testing systems such as the TestQuest Pro™ system by TestQuest, Inc. of Minneapolis, Minn., which are computationally intensive and cannot simply and easily address errors that are introduced during transmission to the subscriber. 
   SUMMARY 
   The present invention provides a system and method for providing quality assurance for interactive television and software application data delivered via a network. Example embodiments of the present invention employ “code checks” that determine “code points” (e.g., a value, code, message, marker or pattern used for integrity checking) based on the original, error-free content as a way to check the content or data package for changes or errors at any later point within the network path from the provider to the subscriber. 
   Using the code checks, at any point in the network path from the provider to the subscriber, the data can be checked for changes or errors by performing some or all of the code checks and comparing the currently determined code point values to the originally determined code point values. If the current values differ from the original or “desired” values, then the data has changed and an error is likely to have occurred. Further action may then be taken to determine the nature of the change or error and to respond to it. 
   Code checks may ensure the integrity of a related set of data, thus for the first time allowing a data provider to be confident that the related set of data is received in its intended form. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  illustrates one possible network in which the system and method of the present invention could be implemented. 
       FIG. 2  illustrates one possible embodiment for establishing the desired code points of the system and method of the present invention. 
       FIG. 3  illustrates one possible embodiment for checking the code points of the system and method of the present invention. 
       FIG. 4  illustrates another possible embodiment of the system and method of the present invention. 
   

   DETAILED DESCRIPTION 
   As shown in  FIG. 2 , in one possible embodiment of the present invention, when the MOD package  280  is being assembled at the content provider, code points  290  are determined for the “desired” (e.g., error-free) content. This content may include, for example, audio  240  and video  220  that may be encoded using, for example, Dolby Labs&#39; AC-3® encoding  250  and MPEG (Motion Picture Experts Group) encoding  230 . The content may also include still art  260 , such as promotional artwork, encoded using, for example, JPEG (Joint Photographic Experts Group) encoding  270 , textual data such as title, cast, and ratings information (e.g., G, PG, R, etc.), and metadata  200  that describes how the GUI is displayed on the screen in, for example, XML format  210 . A code point for each of the elements (e.g., audio, video, still art, textual data, ratings information, metadata, etc) of the MOD package may be determined by a code check. 
   These code checks may be any of a variety of well known techniques for integrity checking. One possible method is to calculate a hash code or checksum for each of the data elements. Another possible technique is to use watermarks such those of Verance Corporation or Digimarc Corporation to embed a code point within an audio, video or graphic element. Simple techniques may also be used as code checks, such as performing a spell check of the text within the content or determining a summary of the text within the content to provide a code point. The set of desired code points which is determined from the code checks also may be protected from tampering by, for example, digitally signing them. 
   The desired code points may be included within the content package as a separate data field, embedded directly within the content or packaged separately. The desired code points also may be calculated before, after or during the process of assembling the content package. 
   As shown in  FIG. 3 , the MOD data package  300  may then be sent to the interactive television provider, and the set of desired code points  390  associated with the MOD data package  300  may be sent separately to a code point monitoring system  380  that may be implemented within the interactive television network (e.g., as software running on one the network elements described previously). Alternatively, the code point monitor may be implemented on a separate piece of hardware or network of hardware such as a computer server or the like. The code point monitor may then access the data package at any number of places within the network to verify the integrity of the data. For example, the code point monitor may check the data after the data package has been loaded into the AMS  310  and BMS  320 , before it is distributed to the VOD servers  340 . Alternatively, the code point monitor may check the data when it is passing through components in the cable plant  350  on its way to the user or when it is passing through the DSM-CC  330 . The code point monitor may also check the data when it has been received by the STB  360  before being sent to the subscriber&#39;s TV  370 . 
   When the code point monitor  380  is, for example, checking the data after it has been loaded into the AMS  310 , the code point monitor may request a copy of the data package  300  from the AMS  310 . The data package is then matched to a particular set of desired code points  390  using, for example, a unique identifier. Once the code point monitor  380  receives the data package  300 , new code points are determined for the data package using the same code checks that were used at the content provider. The new code points are then compared to the set of desired code points  390  that the code point monitor  380  has received from the content provider either via the interactive television network or via some other network. If the new code points are identical to the desired code points, then the data has not been altered since the desired code points were determined. If the new code points differ from the desired code points then the data has been altered and errors may have been introduced. By considering each code point individually, the code point monitor may then determine which data elements have been changed depending on which code points are different from their desired values. For example, if the watermark that was in the audio signal has been altered or is not present then the audio has been altered in some way. In some cases, although the desired code points and new code points are not identical, they may be sufficiently similar that the data may be determined to still be accurate enough for use. For example, if an audio signal is altered, the watermark which was embedded in it will also be altered. However, the code point monitor may determine that the alteration to the watermark is minor and thus the changes to the audio signal are minor enough that the signal may still be used. By comparing the entire set of code points, the code point monitor  380  may also detect if an entire data element is missing or if a data element has been replaced with a data element that belongs in a different data package. 
   Errors may also be detected in the set of code points  390  itself. For example, if code points that have been digitally signed are tampered with, then an error may be determined to have occurred. An error may also be determined to have occurred if the code point monitor  380  has not received the set of desired code points  390  for the data package  300  (e.g., the data package was supposed to include the desired code point information and does not, or the code point monitor never received the desired code point information through its normal means of doing so). 
   After an error or alteration has been detected, the code point monitor may take a variety of actions. For example, if the error is a misspelling in the text of the data package, the code point monitor  380  may attempt to correct the error. In another example, the code point monitor  380  may request that the entire data package  300  or a particular data element of the data package  300  be retransmitted to the particular component that the code point monitor  380  is checking (e.g., the code point monitor  380  may request the content provider to send a new copy of the data package  300  or data element to the AMS  310  so that the error is corrected before the data is passed on to the VOD servers  340 ). The code point monitor  380  may also prevent the content from be accessed (e.g., when the classification has been altered) or simply prevent a portion of the content from being displayed (e.g., if the GUI graphics have been corrupted, the text could still be displayed and the content accessed, but the graphic would not display). The code point monitor  380  may also log that the error has occurred or report the error to some other component in the network. 
   For example, the code point monitor  380  may check the data package  300  as it passes through the cable plant  350  on its way to the subscriber&#39;s STB  360 . The individual data elements of the data package  300  have been sent from different components in the interactive television provider&#39;s network (i.e., the metadata and other GUI information has been sent from the AMS  310  via the DSM-CC  330  while the audio and video have been sent from the VOD server  340 ). However, an error may have occurred because while the metadata and GUI information are for an animated children&#39;s program, the audio and video are for the television show “The Sopranos.” The code point monitor  380  performs the appropriate code check on each of the data elements and then compares the determined current code point values to the set of desired code point values  390 . In performing that comparison, the code point monitor  380  discovers the mismatched content because the current code points for the video and audio data elements do not match the audio and video code points in the set of desired code points  390  while the current metadata and GUI information code points do match their respective desired code points. The code point monitor then blocks the content from being viewed, thus preventing the possibility that a child would be exposed to inappropriate material. 
   An alternative embodiment of the system and method of the present invention is shown in  FIG. 4 . As shown in  FIG. 4 , a content package  440  containing video, audio, metadata and artwork is delivered to a server archive  450 . Control software  460  then calculates desired code point values for the various data elements in the package and separates them from the content package  440 . The content package  440  is then “played out” to the users of the service via the cable television system. When the content is received by the user&#39;s STB, the metadata  400  is processed by the application software  410  of the STB. The current code point values  430  for the metadata are then calculated and sent back to the server side  480  to be compared with the desired code point values  470  to validate that the user interface data is correct or to take corrective action if necessary. The STB can then render  420  the metadata  400  using the appropriate fonts and graphics to provide a polished user interface to the user of the system. 
   In another alternative embodiment, the code point monitor may be implemented within the subscriber&#39;s STB itself. In this embodiment, when the data is received the STB may perform code checks on it before or while the STB is displaying the GUI data or playing the video or audio. The STB may also perform all the post-error detection actions that were previously explained, including data correction, content blocking, and error logging and reporting. 
   The code point monitor may be configured to perform the code checks on every piece of content or to perform the checks only under certain conditions. For example, the code point monitor may check a data package only the first time it is loaded into the system or the first time that it is accessed. In another example, the code point monitor may perform random checks on data packages. In another example, the code point monitor may perform code checks only when the hardware on which it is operating has excess processor time (e.g., the processor has idle processor time that it is not using for other tasks). The code point monitor may also only perform code checks when an operator or subscriber requests that a check be performed, for example. 
   Certain code checks may not require a code point to be included. For example, if the text in the package contains only typical English words then a spell check code check could be performed using any standard spell check dictionary. The absence of any desired code point for a spell check could then indicate that if any word in the text is not present in the dictionary then an error has occurred in the data. 
   The present invention is not limited to the specific embodiments described. It is expected that those skilled in the art will be able to devise other implementations that embody the principles of the present invention and remain within its scope. For example, although explained here in regard to interactive television applications, the present invention may also be applied in other situations where data packages are transmitted over a network and the integrity of the data package cannot be ensured, such as applications which send data packages over the Internet. Furthermore, although explained here in regard to a cable television network, the present invention may also be used with any other kind of networks where it is important to be able to detect errors and respond to them. For example, the present invention may also be used with wireless networks such as satellite transmission or cellular transmission. The network used with the present invention may also employ combinations of networking technologies.