Abstract:
A passenger entertainment system having video-on-demand, audio-on-demand, near video-on-demand, and digital and audio broadcast capabilities delivers multiple programming signals to the passenger seats. The system allocates an RF channel and one of multiple streams in that RF channel to a particular program channel so that channel surfing may be available to the passengers even when multiple programming signals are delivered on a single RF channel.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The invention relates generally to a passenger entertainment system and, more particularly, to a system and method for identifying program selections in a passenger entertainment system that provides video-on-demand, audio-on-demand, near video-on-demand, and digital audio and video broadcasts. 
   2. Description of the Related Art 
     FIG. 1  illustrates selected components of a conventional passenger entertainment system, e.g., an in-flight entertainment (IFE) system, that employs a radio frequency (RF) cable  10  to deliver programming signals to the passenger seats  20 . To deliver multiple programming signals to the passengers and thereby provide the passengers with programming choices, a video modulator  30  is used. In a typical arrangement, the video modulator  30  is connected to multiple video cassette players  31 ,  32 ,  33  that generate a plurality of different NTSC video streams and to a plurality of other inputs (not shown). The video modulator  30  receives the NTSC video stream inputs and the other inputs and modulates each input into a frequency band corresponding to one of multiple RF channels. 
   The passenger seats  20  are each equipped with a seat controller card (SCC)  40  that is tunable to the frequency bands corresponding to the multiple RF channels. The tuning of the SCC is carried out based on inputs from a passenger control unit (PCU)  50  that is provided for each passenger seat and operated by the passenger seated therein. For example, in a passenger entertainment system having 24 RF channels, the PCU  50  may be operated to tune the SCC to one of twenty-four (24) different RF channels. Once the SCC is tuned to receive from the RF channel selected by the passenger, it demodulates the RF signal passed therethrough and sends it to a seat display unit (SDU)  60  for viewing. 
   When the passenger wants to find out what programming selections are available to him or her, the passenger may either channel surf, i.e., toggle between the channels or change the channels up or down sequentially until he or she finds a program of interest, or refer to a hardcopy of an entertainment guide provided by the airline and directly switch to the channel corresponding to the program of interest using a numeric keypad provided on the PCU  50 . In either case, the selected channel number is the same as the RF channel number carrying the program signal (i.e., there is an equally-distributive relationship between RF channels and the programming channels, such as a one-to-one correspondence between the RF channels and programming channels) and that RF channel number is displayed to the passenger on the PCU  50  and/or the SDU  60  to identify or indicate to the passenger the channel number that he or she has selected. In certain cases, the channel identification in the above manner is possible, because only one programming signal or stream is carried on a single RF channel. In other cases, the channel identification is possible because the programming channels are equally distributed across each of the RF channels, such as in a one-to-four, one-to-six, or one-to-fifteen correspondence between the RF channels and the programming channels. 
   However, when multiple programming signals are carried on a single RF channel and the programming channels are not equally distributed among the RF channels, the intuitive relationship between the RF channels and the programming channels breaks down and the conventional way(s) of identifying the program channels is no longer adequate. 
   SUMMARY OF THE INVENTION 
   The invention provides a system and method of identifying program channel selections in a passenger entertainment system that delivers multiple programming signals to the passenger seats on a single RF channel. 
   The invention also provides a system and method of transmitting programming signals and program information to the passenger seats, wherein channel surfing may be available to the passengers even when multiple programming signals are delivered on a single RF channel. 
   The invention further provides a system and method of allocating an RF channel and one of multiple streams in that RF channel to a particular program channel in a passenger entertainment system that provides video-on-demand, audio-on-demand, near video-on-demand, and digital audio and video broadcasts. 
   Additional objects, features and advantages of the invention will be set forth in the description of preferred embodiments which follows. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention is described in detail herein with reference to the drawings in which: 
       FIG. 1  illustrates selected components of a conventional passenger entertainment system that employs an RF cable to deliver programming signals to the passenger seats; 
       FIG. 2  conceptually illustrates a passenger entertainment system according to the invention; 
       FIG. 3  illustrates selected components of the passenger entertainment system according to the invention; 
       FIG. 4  illustrates programming signal paths in the passenger entertainment system according to the invention; 
       FIG. 5  is a block diagram of an exemplary seat controller card used in the passenger entertainment system according to the invention; 
       FIG. 6  is a table identifying program channels that are logically assigned according to the invention and their correlation to the RF channels; 
       FIG. 7  is a flow diagram illustrating the program steps carried out by the system controller to transmit program information including channel assignment information to the passenger seats; 
       FIG. 8  illustrates the data structure of media files that are stored and used in the passenger entertainment system according to the invention; and 
       FIG. 9  illustrates a typical passenger input device by which the passenger makes programming selections. 
   

   The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate presently preferred exemplary embodiments of the invention, and, together with the general description given above and the detailed description of the preferred embodiments given below, serve to explain the principles of the invention. 
   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 2  conceptually depicts the passenger entertainment system according to an embodiment of the invention. A passenger entertainment system for an aircraft or more concisely, an in-flight entertainment (IFE) system, is depicted here and all of the other figures. However, it is understood that the passenger entertainment system according to the invention may be implemented in any vehicle including buses, boats, trains, and jetfoils. Also, a description of some of the details of the passenger entertainment system has been omitted for clarity, and such details may be found in co-pending U.S. patent application Ser. No. 09/085,180, filed May 26, 1998, entitled “Passenger Entertainment System, Method, and Article of Manufacture Having Improved Area Distribution Equipment,” the contents of which are incorporated by reference herein. 
     FIG. 2  shows a core subsystem  100  that is controlled by the aircraft crew through a graphic user interface (GUI)  102  to provide the following functionalities to the passengers: passenger address, audio and video entertainment, seat transfer and lockout, games, and surveys. The audio and video entertainment selections are made by the passengers using a passenger graphic user interface (GUI)  104 . Statistics on the passenger selections are collected and stored for future analysis. 
   The audio and video entertainment includes analog broadcast of audio and video, digital broadcast of audio and video, video-on-demand, audio-on-demand, and near video-on-demand. The digital broadcast function permits multiple digital programs to be broadcast to the passenger seats over several program channels according to a predetermined schedule. The near video-on-demand function permits the same digital program to be broadcast in several successive showings, each started in staggered, regular time intervals. The video-on-demand or audio-on-demand function provides the passengers the ability to select a video or audio presentation and to start, pause, jump forward through, or jump backward through the selected video or audio presentation at any time. 
   The passenger entertainment system of  FIG. 2  further comprises various storage units including a digital media storage unit  130 , also known as a media file server (MFS), an aircraft configuration system (ACS) database  107 , and an in-flight entertainment (IFE) database  108 . The digital media storage unit  130  stores the digital audio and video programs including their set-up and other program information. The ACS database  107  stores data on the hardware configuration of the aircraft, including the number of digital media storage units, the number of video cassette players, the number of RF channels, and others. The IFE database  108  is a storage unit for the system controller for the passenger entertainment system, known as a cabin file server (CFS) (see  FIG. 3 ). The CFS reads out the program information describing the digital audio and video programs from the digital media storage unit  130  and the aircraft configuration data from the ACS database  107 , and generates an entertainment database (digital programming database) that describes the program channel assignment for each passenger seat on the aircraft. The entertainment database is stored in the IFE database  108  and transmitted to the SCC of each passenger seat for storage thereat. 
     FIG. 3  illustrates the CFS  110  and other selected hardware components of the passenger entertainment system according to the invention. The CFS  110  is shown as part of the head end equipment group  101 . The head end equipment group  101  also includes a printer  115  and a primary access terminal  120  coupled to the CFS  110  by an ethernet connection. The primary access terminal  120  provides the operator interface (i.e., the crew GUI) to the passenger entertainment system. The CFS  110  is coupled to the MFS  130  through an ethernet hub (E-HUB)  125 , by which Metadata (program information describing the media files stored on the MFS  130 ) is retrieved. The CFS  110  is shown connected to the ACS database  107  containing the aircraft configuration data and the IFE database  108  containing the entertainment database. 
   Under the control of the CFS  110  through an RS-485 bus, the MFS  130  generates a plurality of MPEG video streams. Up to five media file servers may be provided and each media file server, in the exemplary embodiment, has three outputs. Each media file server is equipped with a quadrature amplitude modulation circuit which is able to compress up to 15 MPEG video streams into each of its three outputs. 
   In parallel with the plural MPEG video streams, a video cassette player  135  supplies NTSC video streams to the video modulator  140 . The video modulator  140  receives the NTSC video streams from the video cassette player  135 , the plural MPEG video streams from the MFS  130 , and other inputs, the details of which are provided in co-pending U.S. patent application Ser. No. 09/085,180, and produces a single RF output signal with multiple RF channels. The RF output signal is supplied to an overhead equipment group  300 , and to a first and business class seat group  400  and an economy class seat group  500  via area distribution boxes (ADB)  210 ,  220 . 
     FIG. 4  illustrates the video modulator  140  receiving three sets of plural MPEG video streams from the MFS  130  and three NTSC video streams from the video cassette player  135 , and producing a single RF output signal that carries all of the received signals in multiple RF channels. In the example shown, each one of RF channels  1 - 3  contains one of the three NTSC video streams from the video cassette player  135  and each one of RF channels  4 - 6  contains one of the three sets of plural (15) MPEG video streams from the MFS  130 . The RF output signal is supplied to the ADB  210 ,  220  and to tapping units  310 ,  320  of the overhead equipment group  300 , from which the RF output signal is distributed to an overhead monitor  330 , or a bulkhead monitor  340  operated with a single lens projector  350 . 
   From the ADB  210 ,  220 , the RF output signal is distributed to audio-visual units (AVUs)  410  of the first and business class section  400 , and to audio-visual units (AVUs)  510  of the economy class section  500 . Each one of AVU  410 ,  510  is provided for a set of two to three passenger seats and contains plural seat controller cards (SCCs), an exemplary one of which is shown in  FIG. 5 . An SCC is provided for each passenger seat, and each SCC controls a corresponding seat display unit (SDU)  420 / 520  and headphone  430 / 530 , and is operated by a corresponding passenger control unit (PCU)  440 / 540 . 
   The block diagram of a representative SCC  515  and its corresponding SDU  520 , headphone  530  and PCU  540  are illustrated in  FIG. 5 . The SCC  515  includes a microprocessor  571 , a memory  572 , and a tuner  573  that is used to extract a signal from one of the RF channels of the multi-channel RF output signal. The selection of the RF channel is made using the PCU  540 . The extracted signal is then demodulated using either an analog demodulator  574  or a QAM demodulator  575 . An audio-video card  576  processes the demodulated signal and outputs video signals to the SDU  520  and audio signals to the headphone  530 . 
   In the exemplary IFE system shown in  FIG. 3 , a 24-channel video modulator  140  is used and as a result, the RF output signal generated by the video modulator  140  and supplied to the passenger seat contains 24 RF channels. The number of program channels, however, is greater than 24, because multiple video streams, up to 15, may be carried on a single RF channel. In the IFE system according to the exemplary embodiment, 28 program channels (PCU channels  01 - 28 ) are carried on the RF channels, as shown in  FIG. 6 . In the exemplary embodiment shown in  FIG. 6 , the RF channels and the program channels are mapped independent of an equally-distributive relationship between the RF channels and program channels, i.e., the channels are not mapped based on a one-to-one, one-to-four, or other similar distributed or proportionate correspondence. Thus, for example, the system may be configured so that RF channel numbers  1 - 10  may each be assigned to one program channel, RF channel number  11  may be assigned to up to fifteen different program channels, RF channel  12 - 13  may be assigned to one program channel with up to fifteen video streams, and so on. Thus, the RF channels are mapped independent of an equally-distributive relationship between the RF channels and program channels.  FIG. 6  also shows a column labeled “UPCU Channel.” This column is provided for embodiments where a universal passenger control unit (UPCU) is used. The UPCU operates like a PCU except that its channel identifier includes 4 characters, both alpha and numeric. 
   The program channel assignments are carried out by the CFS  110  executing the program steps set forth in  FIG. 7 . First, upon power-up of the IFE system, the CFS  110  accesses the ACS database  107  to retrieve data about the IFE system configuration, e.g., the number of media file servers, the number of video cassette players, and the number of RF channels that the video modulator  140  is configured for, and reads in program data corresponding to each of the media files stored in the MFS  130  (Steps  702  and  704 ) to determine the program channel assignment and the service type of the media files stored at the MFS  130 . 
   The contents of program data  113  for a typical media file is shown in  FIG. 8 . They include a media ID, display characters LCD, display characters PCU, movie cycle ID, service map AVOD, service map BDAV, and service map NVOD. The media ID is the file identifier or file name of this media file. Display characters LCD are characters, to be displayed at the SDU  520 , corresponding to the program channel that has been pre-assigned to this media file. Display characters PCU are characters, to be displayed at the PCU  540 , corresponding to the program channel that has been pre-assigned to this media file. 
   Instead of carrying the fields “display characters LCD” and “display characters PCU,” the program data  113  may be configured to point to a table which is stored on the CFS and downloaded as part of the entertainment database to the seats. The characters that are to be displayed at the SDU  520  and the PCU  540  are stored at these table locations. This adds greater flexibility, so that both 2-character and 4-character PCUs may be used on a single aircraft and may be extended to work with analog video selections as well as the digital ones. 
   The movie cycle ID defines the start and stop times of the broadcasting of this media file so that the a common intermission can be set for all digital broadcasts. The service maps AVOD, BDAV, and NVOD are bits that are set to define whether this media file is enabled for audio/video-on-demand (AVOD), broadcast digital audio/video (BDAV), or near video-on-demand (NVOD). The display characters LCD and PCU, and the service map bits AVOD, BDAV, and NVOD are defined separately for each available class of service, so that, for example, a media file may be enabled for AVOD in the first and business class section and pre-assigned program channel  27 , but enabled for BDAV in the economy class section and pre-assigned program channel  10 . 
   For example, a media file for “Toy Story 2” containing the following program data: 
   Media ID—D0001 
   Display Characters LCD—27, 25, 10 
   Display Characters PCU—27, 25, 10 
   Movie Cycle ID—0, 0, 0 
   Service Map AVOD—1, 0, 0 
   Service Map BDAV—0, 0, 1 
   Service Map NVOD—0, 1, 0 
   would have a file name of D0001 and the LCD/PCU channel assignment in First Class would be 27, in Business Class 25, and in Economy Class 10. Further, the movie cycle would be disabled in all three classes and the movie would be enabled for video-on-demand in First Class, for near video-on-demand in Business Class, and broadcast digital in Economy Class. The program data for all of the media files stored at the MFS  130  are interpreted and program channels are assigned to these media files by the CFS  110  in a similar manner (Step  706 ). 
   Subsequently, the CFS  110  assigns the 24 RF channels to the program channels (Step  708  of  FIG. 7 ). The program channels  01 - 09  are assigned to analog video streams carried on RF channels  1 ,  2 ,  3 , and  5 - 10 . The program channels  10 - 24  which are to carry feature films # 7 - 21 , respectively, as designated by the program data for these media files, are assigned to RF channel  11  and its 15 streams. The program channel  25  which is to carry feature film # 22  on a near video-on-demand basis, as designated by the program data for this media file, is assigned to RF channel  12  and its 15 video streams, and the program channel  26  which is to carry feature film # 23  on a near video-on-demand basis, as designated by the program data for this media file, is assigned to RF channel  13  and its 15 video streams. The program channel  27  which is to carry video-on-demand movies is assigned to RF channels  14 - 22 , and the program channel  28  which is to carry audio-on-demand selections is assigned to RF channels  23 - 24 . The program channel assignment information is then stored at the IFE database and transmitted to the corresponding passenger seats (Step  710 ). At each passenger seat, the program channel assignment information is stored in the memory  572  of the corresponding SCC  515  (Step  712 ). 
   In the above example, the RF channel assignments were based on an IFE system having a 24-channel video modulator, 2 triple-deck video cassette players, and 5 media file servers, wherein each MFS has 3 RF outputs, each capable of delivering 27 Mbps of data or 15 independently controllable streams. With a different aircraft configuration, e.g., a 12-channel video modulator, one triple-deck video cassette player, and one media file server, the RF channel assignments would have been different. For example, the RF channels  8 - 10  would not have been assigned to program channels  07 - 09 , because these program channels would be unused as only one video cassette player is employed in the IFE system. In place of program channel  07 , the RF channel  8  would have been assigned to program channels  10 - 24 , the RF channel  9  to program channel  25 , and RF channel  10  to program channel  26 . The remaining program channels would have been assigned to handle the video-on-demand and audio-on-demand selections. For this reason, upon power-up of the IFE system, the CFS  110  accesses the ACS database  107  and retrieves aircraft configuration data relating to the number of available RF channels, the number of media file servers, and the number of video cassette players, prior to the creation of the program channel assignment information. 
   Once the program channel assignment information is stored at the passenger seat, the passenger will be able to browse the available programs by title, view descriptive information about the programs, and select the programs by title. For example, given the program channel assignment of  FIG. 6 , the passenger may view feature films # 1 - 83  by title. If the passenger selects feature film # 1 , the SCC  515  at his or her seat will tune to RF channel  5 , and display feature film # 1  on the SDU  520  and the program channel number  05  on the PCU  540  and/or the SDU  520 . If the passenger selects feature film # 22 , the SCC  515  will tune to RF channel  12 , select and display the video stream corresponding to the next showing of the feature film # 22 , and display the program channel number  25  on the PCU  540  and/or the SDU  520 . If the passenger selects feature film # 24 , the CFS  110  will select any of RF channels  14 - 16  that has an available stream and command the MFS  130  (in particular, MFS2) to transmit the selected film over the available stream. Also, the SCC  515  will tune to the appropriate RF channel, extract the programming signals from the appropriate stream, show the feature film # 24  on the SDU  520 , and display the program channel number  27  (or DV) on the PCU  540  and/or the SDU  520 . 
   In the exemplary embodiment, five media file servers are provided for feature films # 1 - 83 , and each feature film is uniquely allocated to one of the five media file servers. However, in alternative embodiments, the same film may appear on multiple media file servers to increase the number of passengers who can view the same titles. 
   The passenger is also able to control the showing of feature film # 24  or any other video-on-demand feature film or any audio-on-demand selection. The available control functions using the PCU  540  are: Start, Stop, Pause, Jump Back and Jump Forward. The start function begins playback of the program from the current stream position. The pause function temporarily stops playback of the selected program. The passenger will be able to resume playback from the point the program was paused. The stop function stops the playback and exits the program. The passenger will not be able to resume playback from the point the program was stopped. The jump forward function moves forward through the program at a fixed increment of time. The jump backward function moves backward through the program at a fixed increment of time. 
   Alternatively, the passenger is able to channel surf, i.e., select programs by using the channel increase/decrease buttons on the PCU  540  or by operating the numeric keypad on the PCU  540 . For example, if the current program channel indication is  10  and the passenger operates the channel increase button, the program channel indication changes to  11  and the feature film # 8  is displayed on the SDU  520  instead of feature film # 7 . However, it should be noted that, in response to the channel increase operation, although the SCC  515  demodulates the stream corresponding to feature film # 8 , instead of the stream corresponding to feature film # 7 , the SCC  515  remains tuned to the same RF channel at  11 . 
   If the current program channel indication is  10  and the passenger operates the numeric keypad to enter  25 , a near video-on-demand selection, the SCC  515  will tune to the RF channel corresponding to the program channel  25 , i.e., RF channel  12 , and display the stream corresponding to the next showing of the feature film # 22  on the SDU  520 . Also, the program channel number  25  will be displayed on the PCU  540  and/or the SDU  520 . 
     FIG. 9  is a more detailed illustration of the PCU  540  that is used to make program channel selections. Alternatively to the PCU  540 , a universal PCU or a touch panel may be provided. The functions available through the PCU includes menu navigation using arrow keys  901 ,  902 , volume control with volume +/− keys  903 ,  904 , program channel selection with numeric keypad  905  or channel +/− keys  906 ,  907 , and a menu button  908  for selection of functions such as start, pause, stop, jump forward, and jump back. The PCU also has a display  910 , capable of showing 2 or more characters representing  01 - 99 , to display channel selections, or a 4-character display as with the UPCU, capable of showing channels  0001 - 9999  as well as alphanumerics. 
   While particular embodiments according to the invention have been illustrated and described above, it will be clear that the invention can take a variety of forms and embodiments within the scope of the appended claims.