Multi-channel audio distribution for aircraft passenger entertainment and information systems

• US 7,002,994 B1
• Filed: 03/27/2001
• Issued: 02/21/2006
• Est. Priority Date: 03/27/2001
• Status: Active Grant

• Current Assignee: Rockwell Collins, Inc. (Raytheon Technologies Corporation d/b/a RTX)
• Original Assignee: Rockwell Collins, Inc. (Raytheon Technologies Corporation d/b/a RTX)
• Inventors: Haendel, Richard S.
• Primary Examiner(s): Patel, Ajit
• Application Number:
  US09/818,970
• Time in Patent Office: 1,792 Days
• Field of Search: 370/206, 370/211, 370/270, 370/535, 370/537, 370/539, 370/540, 370/542, 370/541, 370/527, 370/529, 370/503, 370/434, 370/480, 370/536, 370/489, 370/486, 370/487, 370/490, 370/485, 370/533, 725/74, 725/75, 725/76, 725/77
• US Class Current: 370/480
• CPC Class Codes: G10L 19/008 Multichannel audio signal coding or decoding using interchannel correlation to reduce redundancy, e.g. joint-stereo, intensity-coding or matrixing
• CPC Class Codes: H04H 20/28 Arrangements for simultaneous broadcast of plural pieces of information
• CPC Class Codes: H04H 20/62 for transportation systems, e.g. in vehicles
• CPC Class Codes: H04H 20/77 using carrier waves
• CPC Class Codes: H04N 21/2146 located in mass transportation means, e.g. aircraft, train or bus flight-deck installations for entertainment or communications B64D11/0015; arrangements specially adapted for transportation systems in broadcast systems H04H20/62; moving wireless networks H04W84/005
• CPC Class Codes: H04N 21/236 Assembling of a multiplex stream, e.g. transport stream, by combining a video stream with other content or additional data, e.g. inserting a URL [Uniform Resource Locator] into a video stream, multiplexing software data into a video stream; Remultiplexing of multiplex streams; Insertion of stuffing bits into the multiplex stream, e.g. to obtain a constant bit-rate; Assembling of a packetised elementary stream multiplexing of data packets for data networks, e.g. RTP/UDP H04L65/00
• CPC Class Codes: H04N 21/8106 involving special audio data, e.g. different tracks for different languages
• CPC Class Codes: H04N 7/52 Systems for transmission of a pulse code modulated video signal with one or more other pulse code modulated signals, e.g. an audio signal or a synchronizing signal assembling of a multiplex stream by combining a video stream with other content or additional data, remultiplexing of multiplex streams, insertion of stuffing bits into the multiplex stream, assembling of a packetised elementary stream at server side H04N21/236; disassembling of a multiplex stream, remultiplexing of multiplex streams, extraction or processing of Service Information, disassembling of packetised elementary stream at client side H04N21/434

Abstract

A method of distributing audio channels to passengers of an aircraft includes digitally encoding a multiplicity of audio channels into a corresponding multiplicity of digital audio channels. Different groups of the digital audio channels are combined into sub-channels having a data rate higher than a data rate of the digital audio channels. The sub-channels are combined into a composite data stream having a data rate higher than the data rate of the sub-channels. A first radio frequency (RF) carrier signal is modulated with the composite data stream to generate a modulated RF signal audio output. The modulated RF signal output containing a large number of audio channels is transmitted over a data network, such as a coaxial cable network, along with a multiplicity of video channel modulated RF carrier signals.

Claims

1. A passenger entertainment system for use in distributing audio and video channels to passenger entertainment stations on an aircraft, the passenger entertainment system comprising:

a data network on the aircraft;

a video system on the aircraft which modulates each of a plurality of video channels on one of a plurality of different radio frequency (RF) carrier signals, and which transmits the plurality of video modulated RF carrier signals to the passenger entertainment stations over the data network;

digital encoding circuitry on the aircraft configured to receive a multiplicity of audio channels and to digitally encode each of the multiplicity of audio channels to thereby provide a multiplicity of digital audio channels;

first layer time division multiplexers on the aircraft each receiving a different plurality of the multiplicity of digital audio channels as inputs, wherein each of the first layer time division multiplexers combines its corresponding plurality of digital audio channels with a synchronization and control channel into a single sub-channel having a data rate higher than a data rate of the digital audio channels;

a second layer time division multiplexer on the aircraft receiving as inputs the sub-channels from each of the first layer time division multiplexers, wherein the second layer time division multiplexer combines the sub-channels with a synchronization and control channel into a composite data stream having a data rate higher than the data rate of the sub-channels; and

modulation circuitry on the aircraft coupled to the second layer time division multiplexer and to the data network, the modulation circuitry modulating a first RF carrier signal with the composite data stream to generate an audio modulated RF carrier signal and transmitting the audio modulated RF carrier signal over the data network with the plurality of video modulated RF carrier signals from the video system.

2. The passenger entertainment system of claim 1, wherein the data network comprises coaxial cables coupled to the passenger entertainment stations.

3. The passenger entertainment system of claim 1, wherein the data network comprises a wireless wideband RF low power transmitter and a plurality of receivers, each located at individual passenger locations.

4. The passenger entertainment system of claim 1, wherein the digital encoding circuitry is further configured to digitally compress each of the multiplicity of audio channels to thereby provide the multiplicity of digital audio channels.

5. The passenger entertainment system of claim 4, wherein the digital encoding circuitry is configured to digitally encode and compress the audio channels into a Moving Picture Experts Group (MPEG) format.

6. The passenger entertainment system of claim 5, wherein the digital encoding circuitry is configured to digitally encode and compress the audio channels using MPEG-2, layer 2 encoding at a data rate of approximately 128 Kbits per second.

7. The passenger entertainment system of claim 6, wherein each of the first layer time division multiplexers is configured to combine approximately 31 digital audio channels and a 128 Kbits per second synchronization and control channel into the single sub-channel at a data rate of approximately 4.096 Mbits per second.

8. The passenger entertainment system of claim 7, wherein the second layer time division multiplexer is configured to combine approximately 15 sub-channels and a 4.096 Mbits per second synchronization and control channel into the composite data stream at a data rate of approximately 65.44 Mbits per second, the composite data stream containing data corresponding to the number of digital audio channels in the approximately 15 sub-channels of approximately 31 digital audio channels.

9. The passenger entertainment system of claim 8, wherein the modulation circuitry modulates the first RF carrier signal using 128 QAM modulation.

10. A method of distributing audio channels to passengers of an aircraft, the method comprising:

digitally encoding a multiplicity of audio channels into a corresponding multiplicity of digital audio channels;

combining each of different pluralities of the digital audio channels in the multiplicity of digital audio channels into a different sub-channel having a data rate higher than a data rate of the digital audio channels;

combining the different sub-channels into a composite data stream having a data rate higher than the data rate of the sub-channels;

modulating a first radio frequency (RF) carrier signal with the composite data stream to generate an audio modulated RF carrier signal;

modulating each of a plurality of video channels on a different one of a plurality of RF carrier signals to generate a plurality of video modulated RF carrier signals; and

transmitting the audio modulated RF carrier signal and the plurality of video modulated RF carrier signals to passenger entertainment stations on the aircraft over a data network on the aircraft, the data network coupling audio and video modulating circuitry on the aircraft to the passenger entertainment stations.

11. The method of claim 10, and further including audio channel distributing steps comprising:

selecting the audio modulated RF carrier signal using an RF tuner coupled to the data network and associated with a particular passenger location;

demodulating the audio modulated RF carrier signal to obtain the composite data stream;

separating the composite data stream into the different sub-channels;

separating the different sub-channels into the different pluralities of the digital audio channels; and

converting a selected digital audio channel into an audio signal.

12. The method of claim 11, and further comprising providing the audio signal to audio device controls associated with an audio device associated with the particular passenger location.

13. The method of claim 12, wherein digitally encoding the multiplicity of audio channels into the corresponding multiplicity of digital audio channels further comprises digitally compressing each of the multiplicity of audio channels to thereby provide the multiplicity of digital audio channels.

14. The method of claim 13, wherein digitally encoding and compressing the audio channels further comprises converting the audio channels into a Moving Picture Experts Group (MPEG) format.

15. The method of claim 14, wherein converting the audio channels into the MPEG format further comprises digitally encoding and compressing the audio channels using MPEG2, layer 2 encoding at a data rate of approximately 128 Kbits per second.

16. The method of claim 15, wherein combining each of the different pluralities of the digital audio channels into different sub-channels further comprises combining approximately 31 digital audio channels and a 128 Kbits per second synchronization and control channel into single sub-channels at a data rate of approximately 4.096 Mbits per second.

17. The method of claim 16, wherein combining the different sub-channels into a composite data stream further comprises combining approximately 15 sub-channels and a 4.096 Mbits per second synchronization and control channel into the composite data stream at a data rate of approximately 65.44 Mbits per second, the composite data stream containing data corresponding to the number of digital audio channels in the approximately 15 sub-channels of approximately 31 digital audio channels.