1. Field of the Invention
This invention relates to broadcast communication systems and, more particularly, to broadcast data propagated in a digital television system.
2. Description of the Background Art
In a conventional Digital Television (DTV) system, video data, audio data, and broadcast data are multiplexed into one program transport stream by a transmitter for downstream processing by at least one receiver. The transmitter, besides being composed of video and audio generators, includes a broadcast data generator for providing supplementary services to the broadcast community; broadcast data does not conform to any standards or format. Examples of broadcast data include: (1) Web home pages; (2) Uniform Resource Locator (URL) of a Web site; and (3) computer programs executable upon a personal computer.
In the receiver, a user of the receiver can select from a set of DTV channels using a tuner to detect an individual modulated DTV channel signal propagated at a given carrier frequency. A demodulator detects the incoming transport stream for the given channel, and the demodulated stream is split into video data, audio data, and broadcast data by a demultiplexer. A video circuit then reconstructs the video from the video data for display on a display device; similarly audio is reconstructed from the audio data.
The broadcast data is processed by a central processing unit. In particular, if the incoming broadcast data is representative of a home page on the Web, or a URL, this data is stored on a disk. If the incoming broadcast data is a program, the program may be executed by the CPU or stored for later execution. In this case, the result of executing the program, if a display is required, will be generated by the CPU and be delivered to the video circuit for processing and display on the display device. Whether or not the data is to be stored, and when a program is to execute, is under control of the user.
Broadcast data oftentimes is transitory, so a user who does not store the broadcast data in the receiver when it is propagated will not have another opportunity to receive the data. Thus, if a user""s receiver is turned-off, inadvertently or intentionally, when data of possible interest is broadcast, the data will be missed by the user. Typically, the receiver is turned-off intentionally while the user, for example, is away from home or has retired for the night, so the user may reduce electricity costs.
Also, it may be possible that a user not having an interest in broadcast data at one time may, at a later time, have renewed interest in the data. Therefore, there are situations in which the user desires to xe2x80x9cbrowsexe2x80x9d and find interesting data later from a stored body of data. Representative of techniques for storing broadcast data for later recall is the subject matter disclosed in U.S. Pat. No. 5,617,565 issued to Augenbraun et al, entitled xe2x80x9cBroadcast Interactive Multimedia Systemxe2x80x9d (BIM System), and assigned to the assignee of this patent application. In this reference, broadcast data in the form of data elements is captured based upon a user profile established initially by the user, and which profile is dynamically altered as the user selects incoming data elements. The BIM System teaches and suggests that all components of the receiver must be energized at all times in order to capture the data and process the data, including the step of dynamic modification of the user profile. Moreover, the BIM System teaches and suggests that all data elements inherently include the data itself, for example, a newspaper article, a technical paper, stock market data, or a magazine article. There is no teaching or suggestion that a data element may be, in essence, a pointer which points to the actual data itself, such as a URL address which points to a Web page. Nor is there any teaching or suggestion that the data may be an executable program which may be invoked at the discretion of the user.
As discerned from the foregoing discussion, the art is devoid of teachings and suggestions related to systems which provide the combined, desirable properties of: low power consumption; capture of broadcast data of interest to the user in the low power consumption mode; the ability to browse for interesting broadcast data at a time following the actual broadcast of the data when the entire receiver is in the full-ON or high power consumption mode; using a pointer to provide the location of data which can be obtained once the receiver is full-ON to thereby mitigate storage requirements in the low power consumption mode; invoking executable code as conveyed by the broadcast data at the discretion of the user; and transfer of the stored data from a first memory operational in the lower power consumption mode to a second memory operational only during the full-ON mode for manipulation by the user.
It should be emphasized, by way of distinguishing the BIM System from the method and concomitant circuitry in accordance with the present invention, that the principles of the BIM system can be incorporated into the operation of the method and circuitry of the present invention so as to more closely match the user""s interest at any given moment, but the BIM System does not include the aforementioned properties which are strictly the domain of the present invention.
The shortcomings of the prior art as well as other limitations and deficiencies are obviated, in accordance with the present invention, by a receiver that is arranged to receive and store broadcast data in a memory during a low power consumption mode, and which is further adapted to transfer the stored broadcast data to a receiver storage device when the receiver is fully energized for browsing the data by the user.
In accordance with a broad method aspect of the present invention, a method for receiving, in a receiver, broadcast data propagated by a multiplexed and modulated digital television signal, the signal including video data as well as at least one elementary stream conveying the broadcast data, the broadcast data including a header and, if necessary, a payload, the receiver including: (i) a tuner for tuning to the signal under control of a user of the receiver; (ii) a demodulator, coupled to the tuner, for demodulating the signal and to generate a transport stream conveying the broadcast data; (iii) a demultiplexer, coupled to the demodulator, for demultiplexing the transport stream to detect the broadcast data; (iv) a data processor responsive to the demultiplexer and control signals from the user for processing broadcast data; (v) a rewritable memory coupled to the data processor; and (vi) a display device for displaying the video data as well as displayable data corresponding the broadcast data, the method including: (a) continuously applying power to the tuner, the demodulator, the demultiplexer, the data processor, and the rewritable memory independent of the on-off state of the display device; (b) upon initialization of the data processor, generating and storing a table in the rewritable memory to be filled in by the data processor during the succeeding steps; (c) processing in the data processor the header to obtain field information conveyed by the header; (d) if the field information indicates that the broadcast data contains a data file to be stored, storing the filename and the payload of the broadcast data corresponding to the data file in the rewritable memory, and proceeding to (f); (e) if the field information indicates that the broadcast data contains a location to be stored, storing the location only in the rewritable memory; and (f) storing the field information in the table for later recall of the field information and either the data file or the location by the user.
In accordance with the broad system aspect of the invention, a receiver for receiving broadcast data propagated by a multiplexed and modulated digital television signal, the signal including video data and at least one elementary stream conveying the broadcast data, the broadcast data including a header and, if necessary, a payload, includes: (1) a tuner for tuning to the signal under control of a user of the receiver; (2) a demodulator, coupled to the tuner, for demodulating the signal to generate a transport stream conveying the broadcast data; (3) a demultiplexer, coupled to the demodulator, for demultiplexing the transport stream to detect the broadcast data; (4) a data processor, responsive to the demultiplexer and input from the user, for processing the broadcast data; (5) a rewritable memory, coupled to the data processor, for storing the broadcast data; and (6) a display device, responsive to the data processor, for displaying, when energized, the video data as well as displayable data representative of the header and payload of the broadcast data, wherein: (a) the tuner, the demodulator, the demultiplexer, the data processor, and the rewritable memory being continuously on independent of the on-off state of the display device; (b) the rewritable memory including a table for storing the broadcast data; and (c) the data processor includes (i) a header processor for processing the header to obtain field information conveyed by the header; (ii) a field processor to determine if the field information indicates that the broadcast data contains a filename to be stored and means for storing the filename and the payload of the broadcast data corresponding to the filename in the rewritable memory; (iii) the field processor also being used to determine if the field information indicates that the broadcast data contains a location to be stored and means for storing the location only in the rewritable memory; and (v) a storage processor for storing the field information as an entry in the table for later recall of the field information and either the filename or the location by the user.
Other aspects of the methodology and concomitant circuitry relate to: processing the broadcast data based upon interest categories selected by the user; processing each incoming elementary broadcast data stream over an interval controlled by the user; and later recalling an using the broadcast data as stored in the rewritable memory under control of the user.