Distribution of a large number of live television programs to individual passengers in an aircraft

A satellite television system that provides live television programming to passengers by integrating direct broadcast satellite services into an in-flight aircraft entertainment system. The system has an antenna disposed on the aircraft that is pointed at a plurality of satellites that are part of a direct broadcast satellite system. The antenna is controlled by an antenna controller and antenna interface unit that send control signals and process status signals to steer the antenna. The antenna is steered to lock it onto RF signals transmitted by the satellites. The antenna interface unit downconverts the received encoded RF signals to provide encoded left hand circularly polarized RF signals and right hand circularly polarized RF signals that contain different sets of television channels. The downconverted encoded RF signals are processed by a receiver to provide encoded video and audio signals of different television channels. The receiver does not decode or D/A convert the downconverted signals. The encoded video and audio signals containing the plurality of channels are modulated in a modulator, which also is used as a combiner to modulate signals derived from other video and audio sources. The modulated and encoded video and audio signals are routed to a video and audio distribution system which distributes the encoded video and audio signals to each passenger's seat. Seat electronics circuitry is located at each passenger's seat that contains a demodulator, decoder, digital to analog converters, and an optional tuner. The seat electronics circuitry demodulates, decodes and D/A converts the modulated and encoded video and audio signals into signals that may be viewed and heard by the passenger at that seat.

BACKGROUND 
The present invention relates generally to in-flight aircraft entertainment 
systems, and more particularly, to a satellite television system that 
distributes a large number of live television programs to passengers of an 
aircraft by way of direct broadcast satellite. 
The assignee of the present invention manufactures in-flight aircraft 
entertainment systems, such as an APAX-150 digital passenger entertainment 
system, for example. The APAX-150 system, along with other commercially 
available systems, distributes audio and video material to passengers 
derived from a variety of sources. For example, existing aircraft 
passenger entertainment systems provide passengers with audio generated 
from audio tape players, movies derived from video tape players, and 
interactive services such as games, shopping and telecommunications. With 
the exception of telecommunication services (air-to-ground telephone 
calls, etc), all existing services utilize on-board sources (tape players, 
etc.) to provide the viewable content. 
According to polls of airline passengers, there is strong interest in live 
television programming as an entertainment option. This may include news, 
sporting events, movies and regular commercial programming. Up to now, 
each airplane has been a closed, self-contained content provider, in the 
sense that once off the ground, all entertainment is generated from within 
the aircraft. This has precluded the offering of live television. Now, 
with the advance in live broadcast satellite technology, it is possible to 
provide this desired service to the flying passenger. 
An article was published by Jim C. Williams entitled "Airborne Satellite 
Television" published in the Fourth Quarter 1994 issue of Avion magazine 
at pages 43 54 that generally describes the concepts of the present 
invention. Another article in the same magazine entitled "MPEG The Great 
Enabler" describes MPEG compression technology which is used in the 
DirectTV digital broadcast satellite system to transmit multiple video and 
audio channels from a ground station to satellite transponders which relay 
them to ground-based receivers where they are decoded and displayed. These 
articles are incorporated herein by reference in their entirety. 
The articles provide a description of the digital broadcast satellite 
system and its operation. The "Airborne Satellite Television" article also 
describes adapting the digital broadcast satellite system to provide live 
television broadcasts to aircraft. However, while a description is 
provided regarding a possible system that could be implemented and the 
problems that needed to be overcome to implement such a system were 
discussed, no details of an actual system were provided, such as system or 
component block diagrams, for example. In fact, the article states that a 
working system was to be developed in the future. The present invention is 
such a system. 
Accordingly, it is an objective of the present invention to provide for a 
satellite television system that distributes a large number of live 
television programs to passengers of an aircraft by way of direct 
broadcast satellite. 
SUMMARY OF THE INVENTION 
To meet the above and other objectives, the present invention is a 
satellite television system that provides live television programming to 
passengers using direct broadcast satellite (DBS) services. The present 
invention combines direct broadcast satellite and audio and video 
entertainment technologies to provide aircraft passengers with live 
in-flight television programming. Copending patent application Ser. No. 
08/667,222, filed Jun. 19, 1996, entitled "Airborne Satellite Television 
System" assigned to the assignee of the present invention, describes 
systems that provide live television programming derived from a direct 
broadcast satellite system to a passenger aircraft. 
The present invention extends the technology disclosed in this copending 
application to provide distribution of the live television programming 
within an aircraft to each passenger seat, where each passenger may 
individually select from among many (approximately 150) channels. Unlike a 
home environment, where a single person may select from all available 
programs while viewing only one at a time, the aircraft environment is 
similar to a large group of individual homes, where each person has a 
system, including antenna and decoder. In the aircraft, however, it is not 
practical to duplicate these elements for each passenger. The present 
invention addresses this problem. 
Passengers are desirous of having live television available at their seat. 
Also, they would like to select from a large number of television 
programs. A low-cost system described in the above-identified copending 
patent application, is not suitable for distributing multiple channels to 
each passenger because the receiver/decoder of this system contains a 
single circuit to receive and process a single television channel. That 
system, while suitable for distributing a single channel to a low-cost 
overhead monitor system, would require as many of these circuits as there 
are channels to be made available, which are approximately 150 in the case 
of the DirectTV system. In addition, the video and audio outputs of each 
of these multitude of circuits would have to be distributed to the 
passengers individually, a task not practical given the limited bandwidth 
of the distribution systems installed in commercial aircraft for this 
purpose. 
The present invention provides for a satellite television system that 
distributes live television service to each passenger without the need to 
duplicate all of the receiver circuitry. Furthermore, the present 
invention distributes all television channels of the direct broadcast 
satellite system to each passenger using currently available aircraft 
entertainment distribution systems. 
More specifically, the satellite television system comprises an antenna 
that is disposed on the aircraft and pointed at a plurality of satellites 
that are part of a direct broadcast satellite system. The antenna is 
controlled by an antenna controller and antenna interface unit that send 
control signals and process status signals to steer the antenna. The 
antenna is steered so that it is locked onto RF signals transmitted by the 
satellites. The antenna interface unit downconverts the received RF 
signals to provide left hand circularly polarized RF signals and right 
hand circularly polarized RF signals that contain different sets of 
television channels. The downconverted RF signals are processed by a 
single receiver to provide encoded video and audio signals comprising a 
plurality of television channels. The receiver does not decode or D/A 
convert the downconverted signals. 
The encoded video and audio signals containing the plurality of channels 
are modulated in a modulator, which also is used as a combiner to modulate 
signals derived from other video and audio sources, such as video and 
audio tape players. The modulated and encoded video and audio signals 
containing the plurality of channels are routed to a video and audio 
distribution system that distributes the encoded video and audio signals 
to each passenger's seat. Seat electronics circuitry is located at each 
passenger's seat that contains a demodulator, decoder, digital to analog 
converter and a tuner. The seat electronics circuitry demodulates, decodes 
and A/D converts the modulated and encoded video and audio signals into 
signals that may be viewed and heard by the passenger at that seat.

DETAILED DESCRIPTION 
Referring to the drawing figures, FIG. 1 shows a top level block diagram of 
a satellite television system 10 in accordance with the principles of the 
present invention. The satellite television system 10 provides live 
television programming to individual seats of passengers on an aircraft 
and permits individual selection of channels by passengers. 
The satellite television system 10 comprises an antenna 11 that is disposed 
adjacent the surface of the aircraft. The antenna 11 is pointed at 
satellites 18, such as DirectTV satellites 18, for example, that are part 
of the existing DirectTV direct broadcast satellite (DBS) system. The 
antenna 11 is steered so that it is locked onto the RF signal transmitted 
by the satellite 18. The antenna 11 is controlled by an antenna controller 
17 that sends control signals and processes status signals to and from the 
antenna 11 by way of an antenna interface unit 12. However, it is to be 
understood that the antenna 11 may be an electronically steered antenna 11 
or a mechanically steered antenna 11. The antenna interface unit 12 
downconverts received MPEG encoded (compressed) RF signals to provide left 
hand circularly polarized RF signals and right hand circularly polarized 
RF signals that contain different sets of encoded television channels. The 
received encoded (compressed) RF signals are in the 12.2-12.7 GHz band 
which are downconverted to IF signals in the 950-1450 MHz band. 
The downconverted encoded IF signals are processed by a receiver 13, which 
does not decode or D/A convert them, to produce encoded video and audio 
signals corresponding to a plurality of encoded television channels. The 
encoded (compressed) video and audio signals are modulated by a modulator 
19, which also is used as a combiner, to modulate signals derived from 
other video and audio sources, such as video and audio tape players. The 
modulated and encoded video and audio signals are then routed to an 
in-seat video and audio distribution system 14 which distributes them to 
each passenger's seat. 
Seat electronics circuitry 50 is located at each passenger's seat that 
contains a demodulator 53, MPEG decoder 54 and digital to analog 
converters 55 (described in detail with reference to FIG. 5). The seat 
electronics circuitry 50 demodulates, decodes and converts the modulated 
and encoded video and audio signals into signals that may be viewed and 
heard by the passenger at that seat by way of a display 51 and head phones 
52. A tuner 57 and game hardware 58 may be provided as part of the seat 
electronics circuitry 50. 
In operation, the receiver serves to receive IF signal from the antenna 11, 
but does not provide MPEG decoding or digital-to-analog conversion 
processes. The output of the receiver 13, rather than a baseband video and 
analog audio output representing a single television program, includes of 
two serial data streams, one for each polarization. These MPEG-encoded 
data streams include all of the live television programming provided by 
the satellites 18. 
The encoded data streams are applied to the RF modulator 19 along with 
signals from other entertainment sources such as video and audio regarding 
safety announcements or digital game data, for example. All of these 
signals are separately modulated and combined onto a single carrier. The 
resulting signal is distributed to the passengers by means of the in-seat 
video and audio distribution system 14, which may be an APAX-150 
distribution system made by Hughes-Avicom International, for example. 
At each passenger seat or seat group, the signal is processed by the seat 
electronics circuitry 50 wherein it is demodulated and processed 
appropriately according to individual signal type. For example, the 
baseband video and audio from video tape players may be applied to a tuner 
57 and converted to a form appropriate for use by the seat's display 51 
and the passenger's headphones 52. Game data is properly processed and 
applied to game hardware 58 to allow its use by the passenger. In the case 
of MPEG-encoded live television data streams, the subject of the present 
invention, the MPEG decoder 54 and digital-to-analog converters 55 located 
within the seat electronics circuitry 50 process the signals and generate 
baseband video and analog audio for use by the passengers. Since all 
television channels received from the satellites 18 are contained within 
the data streams, each passenger can select any particular channel, 
without affecting other passengers. 
Referring to FIG. 2, it shows a block diagram of one embodiment of the 
antenna interface unit 12 employed in the system 10 of FIG. 1. The antenna 
interface unit 12 comprises a downconverter 21 that downconverts the RF 
signals from the 12.2-12.7 GHz band to the 950-1450 MHz band which are 
output to the receiver 13. A servo controller 22 is coupled between the 
antenna controller 17 and the antenna 11. The servo controller 22 
processes antenna position signals to generate elevation motor drive 
signals that are supplied to the antenna 11. The servo controller 22 also 
outputs azimuth control signals to a servo power amplifier 23 that 
generates azimuth motor drive signals that are supplied to the antenna 11. 
Motor position control signals are fed from the antenna 11 to the servo 
power amplifier 23. Power is supplied to the antenna 11 by the servo power 
amplifier 23. A power supply 24 is provided that converts 115 volt AC 
power into appropriate DC voltages for the downconverter 21, the servo 
controller 22 and the servo power amplifier 23. 
Referring to FIG. 3, it shows a block diagram of one embodiment of the 
antenna controller 17 employed in the system of FIG. 1. The antenna 
controller 17 comprises a controller 31 which is coupled to an RS485 
interface 33 and an ARINC 429 interface 34. A power supply 35 is provided 
that converts 115 volt AC power into appropriate DC voltages for the 
controller 31, the RS485 interface 33, and the ARINC 429 interface 34. The 
controller 31 may be an Intel 486 processor, for example. The RS485 
interface 33 is coupled between the antenna interface unit 12 and the 
controller 31 and couples control and status signals thereto. The ARINC 
429 interface 34 is coupled between the aircraft navigation system 15 or 
global positioning system (GPS) 16 and the controller 31 and couples 
inertial reference signals thereto which is used to accurately steer the 
antenna 11 toward the satellite 18. 
Referring to FIG. 4, it shows a block diagram of an embodiment of the 
receiver 13 employed in the system 10 of FIG. 1. The receiver 13 comprises 
a passive mother board 41 which has PCI and ISA busses 46a, 46b. A DSS PC 
card 42, for example, available from Hughes Network Systems and a computer 
processor 43 are coupled to the PCI bus 46a. The DSS PC card 42 and the 
computer processor 43 contain electronics and software that are 
substantially identical to a receiver that is used in commercially 
available DSS systems, such as those made by RCA, for example. Thus, the 
DSS PC card 42 and the computer processor 43 perform the functions of the 
receiver 13. The computer processor 43 has a serial test port 47 that may 
be used to test the processor 43 and DSS PC card 42. A flash disk card 44 
is coupled to the ISA bus 46b and is used to store data and code in a 
manner similar to a hard disk. A power supply 45 is coupled to the passive 
mother board 41 and is used to convert 115 volt AC power into appropriate 
DC voltages for the DSS PC card 42, the computer processor 43, and the 
flash disk card 44. 
Referring to FIG. 5, it shows a block diagram of one embodiment of the seat 
electronics circuitry 50 located at each passenger's seat. The seat 
electronics circuitry 50 includes an MPEG decoder 54, a demodulator 53, 
digital to analog converters 55, and optional tuner 57 and game 
electronics circuitry 58. A power supply 56 is provided that converts 115 
volt AC power into appropriate DC voltages for the demodulator 53, the 
MPEG decoder 54, the digital to analog converters 55, the tuner 57 and the 
game electronics circuitry 58. The seat electronics circuitry 50 
demodulates, decodes and converts the modulated and encoded video and 
audio signals into signals that are viewed and heard by the passenger at 
that seat by way of the display 51 and the headphones 52. 
Thus, a satellite television system that distributes a large number of live 
television programs to passengers of an aircraft by way of direct 
broadcast satellite has been disclosed. 
Furthermore the present invention also provides for a method of 
distributing a large number of television programs derived from satellites 
of a direct broadcast satillite system to each passenger on an aircraft. 
This is self-evident from, and readily understandable by, those skilled in 
the art from a reading of the present specification. 
It is to be understood that the described embodiment is merely illustrative 
of some of the many specific embodiments which represent applications of 
the principles of the present invention. Clearly, numerous and varied 
other arrangements may be readily devised by those skilled in the art 
without departing from the scope of the invention.