Abstract:
Methods and apparatus are described for receiving digital television signals where the receiver is capable of demodulating and demultiplexing the digital television signals from multiple, independent transmission channels. The preferred embodiment of the present invention provides for a Dual Channel Digital TV Receiver which receives signals from two independent transmission channels. In order to address each of the digital television signals from the two independent transmission channels, the Dual Channel Digital TV Receiver of the preferred embodiment of the present invention includes two independent paths for channel demodulation and transport stream demultiplexing. Thus, within the Dual Channel Digital TV Receiver of the preferred embodiment of the present invention, a signal from each of the transmission channels are received, decoded and sent for further processing or viewing, as desired by the user. By providing this dual channel signal processing capability, the Dual Channel Digital TV Receiver of the preferred embodiment allows for versatile program viewing capabilities, including but not limited to, allowing the user to view a program from any one of the transmission channels being accessed, allowing for the recording of programs from one or multiple transmission channels to a digital storage device (which digital storage device may be a part of the Dual Channel Digital TV Receiver), allowing the user to view a program from one transmission channel while recording programs from one or more transmission channels, replaying previously recorded programs, and replaying previously recorded programs while recording programs of one or more transmission channels.

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS  
       [0001]    Applicant claims the benefit of the U.S. Provisional Application No. 60/185,348 entitled “A Dual Channel Digital TV Receiver,” filed Feb. 26, 2000, which application is incorporated herein by reference. 
     
    
     
       FIELD OF THE INVENTION  
         [0002]    This invention relates to digital television receivers, and more particularly, to a method and apparatus for providing a digital television receiver which is fundamentally capable of demodulating and demultiplexing digital TV signals from a plurality of physically independent channels.  
         BACKGROUND OF THE INVENTION  
         [0003]    Digital television broadcasts are well known in the art. Common digital video service networks which provide digital television broadcasts to user&#39;s include digital cable TV, digital satellite TV, video-on-demand, and terrestrial digital TV broadcasting systems. In each of these services a service operator broadcasts information to a multitude of end users in the form of digital television signals provided over a specific transmission channel.  
           [0004]    For example, in digital satellite television broadcasting a service operator transmits its signal over a satellite channel, i.e., from a transmission antenna to a satellite, and then from the satellite to a satellite dish antenna at a user&#39;s home. The signal is then fed from the satellite dish antenna to a receiver for demodulation and demultiplexing so that the user may use the received signal.  
           [0005]    In another example, digital cable television broadcasts are transmitted by a service operator over a hardwired cable network directly into the user&#39;s home. That transmission channel, the digital television cable, is hardwired directly into the user&#39;s receiver for demodulation and demultiplexing, so that the user may use the received signal.  
           [0006]    In each of these examples, the receiver obtains the signal from a specific transmission channel. However, oftentimes users desire to receive their digital television signals from multiple transmission channels.  
           [0007]    Currently, the art does not provide for this functionality. If a user desires multiple transmission channel inputs, then the user must have a receiver to communicate with each respective, independent transmission channel. Each receiver is configured to demodulate and demultiplex the specific signal from the respective transmission channel and then send the end signal to the television for viewing.  
           [0008]    This requirement for multiple receivers to communicate with multiple transmission channels is wasteful, costly and redundant. Requiring the user to obtain multiple receivers also provides an artificial block to competition in television broadcasting. Once a user obtains hardware in conjunction with a specific service, they will be less likely to switch to another service if they are displeased with that original service due to the additional requirement that they also obtain new hardware.  
           [0009]    Thus, there is a need to eliminate this redundancy and provide a system which allows users to access multiple broadcast transmission channels, whether that access is to the multiple channels at the same time or in seriatim. There is a further need to minimize the cost for users to access multiple transmission channels and to provide users with increased choices for receiving information.  
           [0010]    Digital television signals are generally broadcast in the MPEG-2 format. MPEG-2 is a well known standard which was adopted on Nov. 4, 1994 by the ISO (International Organization for Standards) Motion Picture Experts Group (MPEG) for audio/video digital signal compression, configuration and transmission. The MPEG-2 Standard allows for consistent and uniform digital video signal sampling, coding, transmission and reception throughout the world and is very well known in the art.  
           [0011]    Through the known systems designed according to the MPEG-2 Standard (which is also known as International Standard ISO/IEC 13818-1), the packetizing, multiplexing, and sending of coded bit streams of multiple programs may be accomplished. Using this standard signal configuration, multiple programs, along with audio and video overlays may be transmitted by a service operator and received by an end user over a specific transmission channel. Details of MPEG-2 Systems can be also found in the textbook, Digital Video: An Introduction to MPEG-2, Barry G. Haskell and et. al., Champman and Hall, New York, N.Y., USA, 1997.  
           [0012]    Since the adoption of the MPEG-2 Standard, service networks have proliferated around the world which networks provide digital television programming to end users. Each of these digital television broadcast services provide an MPEG-2 signal to end users over one of the transmission channels discussed above.  
         OBJECTS OF THE INVENTION  
         [0013]    Therefore, it is an object of the present invention to provide methods and apparatus for digital television reception which allow users to receive their digital television signals from multiple transmission channels.  
           [0014]    It is yet another object of the present invention to provide methods and apparatus for digital television reception which allow users to eliminate the redundancy of multiple receivers to simultaneously access multiple independent transmission channels.  
           [0015]    It is yet still another object of the present invention to provide methods and apparatus for digital television reception which allow users to reduce the cost of digital television reception.  
           [0016]    These, together with other objects of the present invention, along with the various features of novelty which characterize the present invention, are pointed out with particularity in the claims annexed to and forming a part of this disclosure.  
         SUMMARY OF THE INVENTION  
         [0017]    The above and other objects are achieved by the present invention, which provides methods and apparatus for receiving digital television signals where the receiver is capable of demodulating and demultiplexing the digital television signals from multiple, independent transmission channels.  
           [0018]    The preferred embodiment of the present invention provides for a Dual Channel Digital TV Receiver which receives signals from two independent transmission channels. However, the present invention should not be limited to the preferred embodiment and may be applied to any number of independent transmission channels by extrapolating the principles shown within the preferred Dual Channel Digital TV Receiver.  
           [0019]    In order to address each of the digital television signals from the two independent transmission channels, the Dual Channel Digital TV Receiver of the preferred embodiment of the present invention includes two independent paths for channel demodulation and transport stream demultiplexing. Thus, within the Dual Channel Digital TV Receiver of the preferred embodiment of the present invention, signals from each of the transmission channels are received, decoded and sent for further processing or viewing, as desired by the user.  
           [0020]    By providing this dual channel signal processing capability, the Dual Channel Digital TV Receiver of the preferred embodiment of the present invention allows for versatile program viewing capabilities, including but not limited to, allowing the user to view a program from any one of the transmission channels being accessed, allowing for the recording of programs from one or multiple transmission channels to a digital storage device (which digital storage device may be a part of the Dual Channel Digital TV Receiver), allowing the user to view a program from one transmission channel while recording programs from one or more transmission channels, replaying previously recorded programs, and replaying previously recorded programs while recording programs of one or more transmission channels.  
           [0021]    The preferred receiver for a digital video service network which embodies the present invention comprises: a first means for receiving a first digital television signal from a first transmission channel; a second means for receiving a second digital television signal from a second transmission channel; a means for decoding at least the first digital television signal or the second digital television signal; and a means for providing an output signal reflective of a television program contained within either the first digital television signal or the second digital television signal.  
           [0022]    The preferred method for receiving digital television signals used by the preferred embodiment of the present invention, comprises the steps of: receiving a first digital television signal from a first transmission channel; receiving a second digital television signal from a second transmission channel; decoding the first digital television signal; decoding the second digital television signal; and providing an output signal reflective of a television program contained within either the first digital television signal or the second digital television signal. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0023]    The foregoing and other objects, advantages and features of the invention, and the manner in which the same are accomplished, will become more readily apparent upon consideration of the following detailed description of the preferred embodiment of the present invention taken in conjunction with the accompanying drawings which illustrate preferred and exemplary embodiments, and wherein:  
         [0024]    [0024]FIG. 1 shows a basic block diagram illustration of the functional architecture of the Dual Channel Digital TV Receiver of the preferred embodiment of the present invention.  
         [0025]    [0025]FIG. 2 shows a basic block diagram illustration of the program data flow for the Dual Channel Digital TV Receiver of the preferred embodiment of the present invention when the receiver is playing a specific program selected by the user from one of the transmission channels.  
         [0026]    [0026]FIG. 3 shows a basic block diagram illustration of the program data flow for the Dual Channel Digital TV Receiver of the preferred embodiment of the present invention when the receiver is recording one or more selected programs from the signals of one or both independent transmission channels which feed into the Dual Channel Digital TV Receiver  100 .  
         [0027]    [0027]FIG. 4 shows a basic block diagram illustration of the program data flow for the Dual Channel Digital TV Receiver of the preferred embodiment of the present invention when the receiver is simultaneously recording one or more selected program(s) from the signals of one or both independent transmission channels which feed into the Dual Channel Digital TV Receiver and, at the same time, directly playing a specific program selected by the user from the combined signal received from one of the independent transmission channels.  
         [0028]    [0028]FIG. 5 shows a basic block diagram illustration of the program data flow for the Dual Channel Digital TV Receiver  100  of the preferred embodiment of the present invention when the receiver playing back a previously stored program.  
         [0029]    [0029]FIG. 6 shows a basic block diagram illustration of the program data flow for the Dual Channel Digital TV Receiver of the preferred embodiment of the present invention when the receiver is simultaneously recording one or more selected program(s) from the signals of one or both independent transmission channels which feed into the Dual Channel Digital TV Receiver and, at the same time replaying a specific previously recorded program. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0030]    The following description is provided to enable any person skilled in the art to make and use the invention and sets forth the best modes presently contemplated by the inventors for carrying out this invention. Various modifications however, will remain readily apparent to those skilled in the art, since the generic principles of the present invention have been completely defined.  
         [0031]    The present invention provides methods and apparatus for receiving and processing digital television signals from multiple, independent transmission channels. By way of example, the preferred embodiments of the present invention describe various structures and functionalities for a Dual Channel Digital TV Receiver whose fundamental characteristic is to process the digital television signal from two physically independent transmission channels. However, the present invention should not be limited to the preferred embodiment and may be applied to any number of independent transmission channels by extrapolating the principles shown within the preferred Dual Channel Digital TV Receiver.  
         [0032]    As shown in the following detailed description of the preferred embodiment, the Dual Channel Digital TV Receiver of the preferred embodiment of the present invention can deal with multiple independent programs that a user selects in one or two different and physically independent channels. In the digital television signal broadcast across each independent transmission channel, the programs are composed of one or more (packetized) elementary bitstreams. Each packetized bitstream is labeled with a Packet Identification (PID).  
         [0033]    Through use of the below described dual channel processing capability, the Dual Channel Digital TV Receiver of the preferred embodiment of the present invention enables various program viewing options for the users: the user can view a program of one channel, select and record (or, save) program(s) of one or both channels to a digital storage device of the preferred system, view a program of one channel while simultaneously recording the program(s) of that same channel, the other channel, or both channels to the digital storage device, replay the recorded programs, and replay the recorded programs while simultaneously recording program(s) of one or both channels.  
         [0034]    [0034]FIG. 1 shows a block diagram illustration of the functional architecture of the Dual Channel Digital TV Receiver  100  of the preferred embodiment of the present invention.  
         [0035]    The preferred Dual Channel Digital TV Receiver  100  of the present invention receives two separate digital television signals from each of two respective independent transmission channels (not shown). Each of these digital television signals may be received via a satellite antenna, a hardwired digital cable or any other signal reception system commonly known in the art. In the preferred Dual Channel Digital TV Receiver  100  of the present invention, the two received digital television signals are then sent via a single input  106  to the preferred Dual Channel Digital TV Receiver  100 .  
         [0036]    As shown in FIG. 1, the preferred Dual Channel Digital TV Receiver  100  includes two independent channel demodulators  101 ,  102 . Each of the two independent channel demodulators  101 ,  102  receives the combined received digital television signals which are provided at input  106 . Each of the two independent channel demodulators  101 ,  102  extracts channel specific bitstreams from one of the respective received signals of one of the two respective, independent transmission channels.  
         [0037]    Each of the independent channel demodulators  101 ,  102  is configured to demodulate the signal received at input  106  based upon a channel selection command  121 ,  122  sent from a System Manager  110 . These channel selection commands  121 ,  122  are chosen based upon the user&#39;s tuning choices and selections which are input at a User Interface  103 . This User Interface interfaces between the System Manager  110  and the user.  
         [0038]    Once the independent channel demodulators  101 ,  102  extract their specific bitstreams of the chosen channels from the combined received digital television signal, those channel specific bitstreams are then fed to two independent Transport Stream (TS) Demultiplexers  104 ,  105 . The Transport Stream (TS) Demultiplexers  104 ,  105  then demultiplex the TS packets coming out of the channel demodulation units  101 , 102 .  
         [0039]    The preferred Dual Channel Digital TV Receiver  100  of the present invention includes the System Manager  110  to control the flow of information within and the operation of the Dual Channel Digital TV Receiver  100 . When the channel specific bitstreams are demultiplexed by the two independent Transport Stream (TS) Demultiplexers  104 ,  105 , the System Manager  110  obtains Program Specific Information (PSI)  123 ,  124  for each of the respective chosen channel specific bitstreams. The Program Specific Information (PSI) is embedded in the TS packets as tables. The System Manager  110  delivers the Program Specific Information (PSI)  123 ,  124  of the selected channel specific bitstreams to the user at the User Interface  103 , and receives the user&#39;s choices regarding program selection, request for viewing, recording, and replaying, etc.  
         [0040]    In response to the user&#39;s selections, the System Manager  110  controls and manages the flow of the bitstreams regarding the selected programs in accordance with the user&#39;s requests and feeds packet identifications (PIDs)  125 ,  126  to the associated channel specific TS Demultiplexers  104 , 105  to select the associated bitstreams of the programs that the user has selected.  
         [0041]    The preferred Dual Channel Digital TV Receiver  100  of the present invention also includes a Digital Storage Device  107  for saving and reading the bitstreams of selected programs, a controller which controls and manages the saving and reading process of the bitstreams of the programs that the user has selected, and Application Decoders  108  which decode the coded audio and video bitstreams of a given program that the controller assigns for viewing.  
         [0042]    A specific description of the Program Specific Information (PSI) in an MPEG-2 digital television signal can be obtained from the International Standard ISO/IEC 13818-1, which is known in the art and incorporated herein by reference. International Standard ISO/IEC 13818-1 also includes an explanation of TS packetization, and reference should be made to the TS syntax defined therein.  
         [0043]    Typical steps which may be used to get the Program Specific Information (PSI) from the Transport Stream Packets is to first find the Program Associated Table (PAT) which contains the program numbers and the Packet Identification (PID) of the associated Program Map Tables (PMT). Then, once the Program Map Tables (PMT) are obtained, the respective Packet Identifications (PID) of the elementary or packetized elementary bitstreams of the programs available in the channel can be obtained from the Program Map Tables (PMT), and utilized by the System Manager  110 , as discussed above to process the bitstreams of the programs that the user has selected for viewing and or processing.  
         [0044]    The basic operation of the Dual Channel Digital TV Receiver  100  of the preferred embodiment of the present invention shown in FIG. 1 follows. First, the user selects two channels (Channel  1  and Channel  2 ) for processing by the preferred Dual Channel Digital TV Receiver  100 . The user selects these channels by inputting their selection into the User Interface  103 .  
         [0045]    Once these channel selections are input into the User Interface  103  by the User, the User Interface  103  then instructs the System Manager  110  to configure the respective Channel Demodulators  101 ,  102  by sending inputs  121 ,  122  to the Channel Demodulators  101 ,  102 . The Channel Demodulators  101 ,  102  are configured to extract the chosen channel specific bitstreams  127 ,  128  from the combined digital television signal at input  106 , and provide those chosen channel specific bitstreams  127 ,  128  to the respective TS Demultiplexers  104 ,  105 .  
         [0046]    From the received channel specific bitstreams  127 , 128 , the TS Demultiplexers  104 , 105  then provides the System Manager  110  with the Program Specific Information (PSI) for each channel (PSI  1   123  and PSI  2   124 ). The Program Specific Information (PSI) for each channel (PSI  1   123  and PSI  2   124 ) contains the programs and the associated Packet Identification (PID) information for those programs.  
         [0047]    The System Manager  110  delivers the Program Specific Information (PSI) from the respective selected channels to the User Interface  103  for the user to select specific program(s) to view and/or save. Based on the user&#39;s instructions input into the User Interface  103  to view and/or save specific program(s), the System Manager  110  feeds the Packet Identifications (PID)s associated with the selected program(s) along inputs  125 ,  126  to the respective TS Demultiplexers  104 ,  105  for the specific channels.  
         [0048]    Based on the user&#39;s instructions input into the User Interface  103 , the System Manager  110  also manages the flow of bitstreams of the selected programs through the preferred Dual Channel Digital TV Receiver  100  in accordance with the user&#39;s requests. That is, the specific program which was selected by the user for viewing goes through the TS Demultiplexers  104 ,  105  along the respective inputs  129 ,  130  through the System Manager  110  to the Application Decoders  108 .  
         [0049]    Additionally, the bitstreams from the specific program(s) which were selected bythe user for saving or recording are sent from the TS Demultiplexers  104 ,  105  along the respective inputs  129 ,  130  through the System Manager  110  to the Digital Storage Device  109 . In the recording mode for the Dual Channel Digital TV Receiver  100  of the preferred embodiment of the present invention, the System Manager  110  controls the Digital Storage Device  107 , and the user can decide to save multiple programs simultaneously. Simultaneous recording of multiple programs is explained in more detail below with reference to FIGS. 3, 4 and  6 .  
         [0050]    In the preferred embodiment of the Dual Channel Digital TV Receiver  100 , the Dual Channel Digital TV Receiver  100  itself contains a Digital Storage Device  107 . However, the present invention should not be so limited and the Digital Storage Device  107  maybe its own self contained unit. A further receiver may be constructed according to the present invention without a Digital Storage Device  107 , whereby the Dual Channel Digital TV Receiver  100  can operate only in “program viewing” mode or programs may be saved to an external Digital Storage Device  107 .  
         [0051]    The preferred embodiment of the Dual Channel Digital TV Receiver  100  also allows the user to request to the System manager  110  to replay a previously saved program which was stored in the Digital Storage Device  107 . When the user inputs a replay request into the User Interface  103 , the System Manager  110  reads the selected previously recorded program from the Digital Storage Device  107  and delivers the selected previously recorded program to the Application Decoders  108 . The Applications Decoders  108  then decode the incoming coded bitstreams of the selected program and send out decoded audio and video output signal  131 ,  132 .  
         [0052]    The preferred embodiment of the Dual Channel Digital TV Receiver  100  also allows the user to request to digitally record selected programs from the transmission channels while viewing another previously recorded program. When the user decides to operate in this mode the specific program(s) which the user selects for recording are sent from the specific TS Demultiplexer  104  or  105 , as the case may be, to the Digital Storage Device  107 , and the selected previously recorded program is simultaneously sent from the Digital Storage Device  107  to the Application Decoders  108 .  
         [0053]    [0053]FIG. 2 shows a basic block diagram illustration of the program data flow for the Dual Channel Digital TV Receiver  100  of the preferred embodiment of the present invention when the receiver is directly playing a specific program selected by the user from the combined signal received from one of the independent transmission channels. As shown in FIGS.  2 - 6 , the internally connected arrow lines inside the System Manager  110  represent the flow of the selected program(s) data within the Dual Channel Digital TV Receiver  100  of the preferred embodiment of the present invention.  
         [0054]    In this “single channel decode mode,” the user selects a specific program for viewing from the Program Specific Information (PSI) received from Channel  1 . The user inputs their instructions at the User Interface  103 . From this instruction at the User Interface  103 , the System Manager  110  provides Packet Identification (PID) control signals for that selected program along input  125  to TS Demultiplexer  104  and instructs the TS Demultiplexer  104  to demultiplex Channel  1 ′s bitstream signal  127 .  
         [0055]    Based upon this instruction signal  125  received from the System Manager  110 , the TS Demultiplexer  104  provides the selected program specific bitstream  129  to the System Manager  110 . The System Manager  110  next routes that bitstream signal  161  to the Application Decoders  108 . The Applications Decoders  108  then decode the incoming coded bitstreams of the selected program  161  and send out decoded audio and video output signal  131 ,  132 .  
         [0056]    [0056]FIG. 3 shows a basic block diagram illustration of the program data flow for the Dual Channel Digital TV Receiver  100  of the preferred embodiment of the present invention when the receiver is recording one or more selected program(s) from the signals of one or both independent transmission channels which feed into the Dual Channel Digital TV Receiver  100 .  
         [0057]    In this “record mode,” the user selects specific programs for recording/saving from the Program Specific Information (PSI) received from the transmission Channels  1  and/or  2 . The user inputs their instructions at the User Interface  103 .  
         [0058]    From this instruction at the User Interface  103 , the System Manager  110  provides Packet Identification (PID) control signals for the selected program(s) along input  125  to TS Demultiplexer  104  for any program being carried within the channel specific bitstream signal from Channel  1   127 , and the System Manager  110  further provides Packet Identification (PID) control signals for the selected program(s) along input  126  to TS Demultiplexer  105  for any program being carried within the channel specific bitstream signal from Channel  2   128 . Using these control signals  125 ,  126 , the System Manager  110  instructs the TS Demultiplexers  104 ,  105 , as the case may be, to demultiplex their respective Channel specific bitstream signal  127 ,  128 .  
         [0059]    Based upon these instruction signals  125 ,  126  received from the System Manager  110 , the TS Demultiplexers  104 ,  105  provide the selected program specific bitstreams  129 ,  130  to the System Manager  110 . The System Manager  110  next routes that bitstream signals  162 ,  163  to the save input  133  of the Digital Storage Device  107  for recording, whether that recording is simultaneously conducted for multiple selected programs or merely direct singular recording for one program.  
         [0060]    [0060]FIG. 4 shows a basic block diagram illustration of the program data flow for the Dual Channel Digital TV Receiver  100  of the preferred embodiment of the present invention when the receiver is simultaneously recording one or more selected program(s) from the signals of one or both independent transmission channels which feed into the Dual Channel Digital TV Receiver  100 , and, at the same time directly playing a specific program selected by the user from the combined signal received from one of the independent transmission channels.  
         [0061]    In this “record and display mode,” the user selects the specific programs for viewing and/or recording/saving from the Program Specific Information (PSI) received from the transmission Channels  1  and  2 . The user inputs their selections for viewing and recording at the User Interface  103 .  
         [0062]    From these instructions and selections at the User Interface  103 , the System Manager  110  provides Packet Identification (PID) control signals for the selected programs along input  125  to TS Demultiplexer  104  for any selected programs being carried within the channel specific bitstream signal from Channel  1   127 , and the System Manager  110  further provides Packet Identification (PID) control signals for the selected programs along input  126  to TS Demultiplexer  105  for any chosen programs being carried within the channel specific bitstream signal from Channel  2   128 . Using these control signals  125 ,  126 , the System Manager  10  instructs the TS Demultiplexers  104 ,  105 , as the case maybe, to demultiplex their respective Channel specific bitstream signal  127 ,  128 .  
         [0063]    Based upon these instruction signals  125 ,  126  received from the System Manager  110 , the TS Demultiplexers  104 ,  105  provide the selected program specific bitstreams  129 ,  130  to the System Manager  110 .  
         [0064]    For the programs that the user selected for recording/saving, the System Manager  110  next routes those bitstream signals  164 ,  165  to the save input  133  of the Digital Storage Device  107  for recording. In the example shown in FIG. 4, that recording is simultaneously conducted for multiple selected programs. For the program that the user has selected for immediate viewing, the System Manager  110  routes that bitstream signal  166  to the Application Decoders  108 . The Applications Decoders  108  then decode the incoming coded bitstreams of the selected program  166  and send out decoded audio and video output signal  131 ,  132 .  
         [0065]    [0065]FIG. 5 shows a basic block diagram illustration of the program data flow for the Dual Channel Digital TV Receiver  100  of the preferred embodiment of the present invention when the receiver playing back a previously stored program.  
         [0066]    In this “playback mode,” the user has selected a previously stored program to be replayed from the Digital Storage Device  107 . The operation of storing selected programs is discussed in detail above with reference to FIGS. 3 and 4.  
         [0067]    Once the user has input their instructions to replay a previously stored selected program at the User Interface  103 , the System Manager  110  provides Packet Identification (PID) control signals or file control signals for that previously stored selected program to the Digital Storage Device  107  and instructs the Digital Storage Device  107  to download the corresponding previously stored selected program to read output  134 .  
         [0068]    Once the System Manager receives those packet bitstreams at read output  134 , the System Manager  110  next routes that bitstream signal  167  to the Application Decoders  108 . The Applications Decoders  108  then decode the incoming coded bitstreams of the selected program  167  and send out decoded audio and video output signal  131 ,  132 .  
         [0069]    [0069]FIG. 6 shows a basic block diagram illustration of the program data flow for the Dual Channel Digital TV Receiver  100  of the preferred embodiment of the present invention when the receiver is simultaneously recording one or more selected program(s) from the signals of one or both independent transmission channels which feed into the Dual Channel Digital TV Receiver  100 , and, at the same time replaying a specific previously recorded program.  
         [0070]    In this “record and playback mode,” the user selects the specific programs for recording and/or playback from the Program Specific Information (PSI) which has either been received from the transmission Channels  1  and  2  or relates to the previously recorded programs being stored within the Digital Storage Device  107 . The user inputs their selections for recording and playback at the User Interface  103 .  
         [0071]    From these instructions and selections at the User Interface  103 , the System Manager  110  provides Packet Identification (PID) control signals for the selected programs along input  125  to TS Demultiplexer  104  for any programs selected for recording which are being carried within the channel specific bitstream signal from Channel  1   127 , and the System Manager  110  further provides Packet Identification (PID) control signals for the selected programs along input  126  to TS Demultiplexer  105  for any programs selected for recording which are being carried within the channel specific bitstream signal from Channel  2   128 . Using these control signals  125 ,  126 , the System Manager  110  instructs the TS Demultiplexers  104 ,  105 , as the case may be, to demultiplex their respective Channel specific bitstream signal  127 ,  128 .  
         [0072]    Based upon these instruction signals  125 ,  126  received from the System Manager  110 , the TS Demultiplexers  104 , 105  provide the selected program specific bitstreams  129 , 130  to the System Manager  110 .  
         [0073]    For these new programs which the user has now selected for recording/saving, the System Manager  110  next routes those bitstream signals  168 ,  169  to the save input  133  of the Digital Storage Device  107  for recording. In the example shown in FIG. 6, that recording is simultaneously conducted for multiple selected programs  168 ,  169 .  
         [0074]    For the program that the user has selected for immediate playback, the System Manager  110  provides Packet Identification (PID) control signals or file control signals for that selected program to the Digital Storage Device  107  and instructs the Digital Storage Device  107  to download the corresponding previously stored selected program to read output  134 .  
         [0075]    Once the System Manager receives those packet bitstreams at read output  134 , the System Manager  110  next routes that bitstream signal  170  to the Application Decoders  108 . The Applications Decoders  108  then decode the incoming coded bitstreams of the selected program  170  and send out decoded audio and video output signal  131 ,  132 .  
         [0076]    Accordingly, it will be understood that the Dual Channel Digital TV Receiver  100  preferred embodiment of the present invention has been disclosed by way of example only, and that other modifications and alterations may occur to those skilled in the art without departing from the scope and spirit of the appended claims.  
         [0077]    Those skilled in the art will appreciate the various adaptations and modifications of the just described preferred embodiments can be configured without departing from the scope and spirit of the invention. Therefore, it is to be understood that, within the scope of the appended claims, the invention may be practiced other than as specifically described herein.