EP1676432A2

EP1676432A2 - Multiplexed audio and data transmission over digital content delivery channels

Info

Publication number: EP1676432A2
Application number: EP04794805A
Authority: EP
Inventors: Riza Dr. Director of Systems Eng. AKTURAN
Original assignee: Sirius XM Radio Inc
Current assignee: Sirius XM Radio Inc
Priority date: 2003-10-22
Filing date: 2004-10-12
Publication date: 2006-07-05
Also published as: WO2005043881A2; WO2005043881A3

Abstract

Systems and methods for multiplexing content from variable-rate audio channels with content from one or more data channels uses an audio/data multiplexing module. This module time-multiplexes multiple audio and data channels into a single data channel output, and send it to a logical channel. The audio and data packets in the multiplexed signal are tagged on packets of audio or data information within the multiplexed signal. Receive modules receive and select a single logical channel for output. These modules include audio/data de-multiplexing modules that receive and de-multiplex the multiplexed audio and data content from a logical channel into separate paths, where the users of such systems can listen to audio content while at the same time receiving data content; such as artist pictures or weather information.

Description

MULTIPLEXED AUDIO AND DATA TRANSMISSION OVER DIGITAL CONTENT DELIVERY CHANNELS This invention relates to methods and systems for transmission of signals comprising combined, multiplexed audio and data content to a plurality of receivers that can output both the audio and data content of such signals from a common channel. These systems and methods are especially useful for transmitting, receiving and outputting such signals from terrestrial and satellite transmitters of Satellite Digital Audio ' Radio Systems (SDARS). The following patents and patent applications related to these systems are hereby incorporated by reference as though fully set forth here: U.S. Patent No. Title Issue Date 6,564,053 Efficient High Latitude Service Area Satellite Mobile May 13, 2003 Broadcasting Systems 6,023,616 Satellite Broadcast Receiver System Feb. 8, 2000

5,864,579 Digital Radio Satellite And Terrestrial Ubiquitous Jan. 26, 1999 Broadcasting System Using Spread Spectrum Modulation 5,794, 138 Satellite Broadcast System Rcccivei Aug 1 1 , 1998

5,592,471 Mobile Radio Receivers Using Time Diversity To Jan. 7, 1997 Avoid Service Outages In Multichannel Broadcast Transmission Systems 5,485,485 Radio Frequency Broadcasting Systems And Jan. 16, 1996 Methods Using Two Low-Cost Geosynchronus Satellites And Hemispherical Coverage Antennas 5,319,673 Radio Frequency Broadcasting Systems And Jun. 7, 1994 Methods Using Two Low-Cost Geosynchronus Satellites

EPO Patent Title Date Of Pub. EP 0959 573 A2 System For Efficiently Broadcasting Via Satellite To Nov. 24, 1999 EP 990303823 Mobile Receivers In Service Areas At High Latitude

Int'l. Pub. No. Title Intl. Pub. Date

WO 01/33729 Al Method And System For Providing Geographic Specific Services In 10 May 2001 A Satellite Communications Network

WO 01/33720 A3 Method And Apparatus For Selectively Operating Satellites In 10 May 2001 Tundra Orbits To Reduce Receiver Buffering Requirements For Time Diversity Signals

Satellite Digital Audio Radio Services (SDARS), such as those provided by Sirius Satellite Radio Inc. and XM Satellite Radio, Inc, are examples of wireless content delivery systems that use satellite and terrestrial transmitters to deliver signals comprising audio and data content to receivers located at or near the earth's surface. In such systems, receivers often work better with satellite signal transmissions in rural areas, and with terrestrial signal transmission in more urbanized areas. SDARS systems provide various broadcast content (i.e. audio and data) delivery services over a large system service area, e.g. CONUS (the mainland United States). Signal delivery is made to subscribing receivers within a system service area from geostationary or geo -synchronous satellite networks, simultaneously with ground-based terrestrial signal delivery networks. Although this invention could be applicable to a wide range of digital signal transmission systems, preferred embodiments relate to SDARS systems.

Delivery of signals comprising audio content and signals comprising data content over digital media transmission channels has heretofore been made over separate logical channels for the audio content and the data content. Such delivery precludes receiving both audio and data content from the same logical channel.

This invention provides systems and methods to transmit, receive and output audio and data content from a single logical channel. Preferred embodiments comprise a transmission module that can transmit multiple logical channels, with each channel delivering signals comprising both audio and data content. Such a transmission module multiplexes, preferably in separate packets, content from one or more audio channels, with content from one or more data channels, using an audio/data multiplexer module. This module time-multiplexes the selected multiple audio and data channels into a single output signal for delivery to a common transmission channel.

SDARS systems use variable rate audio coders. Thus, in SDARS, the multiplexer preferably accommodates variable rate audio and variable rate data transmissions. For example, when a user tunes to an SDARS channel to listen to audio, the user can also receive data in the same logical channel transmission mechanism. An example of such data is a digital picture of the artist performing a currently-playing song. More generally, the data may include information about currently-playing or to-be-played audio information, or other text such as information about currently active channels carrying e.g. weather, graphics, or news.

The data content may contain the picture or a graphical representation of the artist of the currently playing song on the audio channel; the data may also contain other types of data that may be relevant to the user such as weather text or graphics. Time- multiplexed audio content and data content are preferably tagged with headers to denote the content type in a given packet of information transmitted from the multiplexed channel.

Preferred embodiments also comprise receiver modules that can receive and select a single logical channel. These modules comprise an audio/data de-multiplexer module that receives and de-multiplexes signals comprising multiplexed audio and data content from a logical channel into separate paths. A user can choose to output from a receiver one of the following channels: a single audio channel, or a single data channel, or a multiplexed audio and data channel in which case the data content is output prom a data port on the receiver while the user is listening to the audio content from an audio port.

Identification information of the signal from each logical channel can be transmitted from a service channel, enabling a receiver to monitor and learn the content type of each logical channel when signal reception begins and while signal reception is ongoing.

In SDARS, for example, these systems and methods can multiplex music and the musician's picture or video over the same logical SDARS channel. Only one physical and logical channel demodulator is needed in the receiver for reception of this combined audio and data. The receiver may also output audio and data from separate^' audio and data ports.

BRIEF DESCRIPTION OF THE DRAWINGS

This invention can be better understood by reference to the accompanying drawing, which illustrates an embodiment of a combined audio/data content transmission module and a combined audio/data content reception module. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The drawing shows transmission module 10 that multiplexes content from selected audio channels 11 and 12 with content from one or more data channels 13 and 14 using an audio/data multiplexing module. After audio to data conversion and variable- rate coding of the audio content at blocks 15 and 16, and processing of the data from blocks 13 and 14 at blocks 17 and 18, module 10 time-multiplexes the selected audio and multiple data channels at block 19 into a single output signal 20, and sends the combined content signal, via logical channelization 21, to physical channelization and transmission 22.

Receive module 30 receives and selects single logical channel 32. Module 30 includes audio/data de-multiplexing module 31 that receives, and physically dechannelizes the signal at block 39, and de-multiplexes the multiplexed audio and data content from logical channel 32 into separate paths 33 and 34. If the selected logical channel is an audio-only or a data-only channel, the content is sent to its proper audio decoding or data processing route. If the selected channel is a multiplexed channel, the receiver outputs variable-rate audio content 36 and data content 37 from a single path, or from separate multiple paths, to an output port or device after passing the audio content packets from audio A/D (analog-to-digital) converter/decoder 35 and after passing the data content from data processing module 38.

Claims

1. A system comprising a transmission module for outputting combined variable-rate audio content and data content in a common channel comprises: at least one source for audio content; at least one source for data content; a multiplexer for combining said audio content and said data content into a multiplexed signal on a common channel; and a system for transmitting said multiplexed signal with combined audio and data content to a plurality of receivers located at or near the earth's surface.

2. The system of claim 1 further comprising a satellite system for transmitting said signal.

3. The system of claim 2 wherein said satellite system is an SDARS.

4. The system of claim 1 further comprising means for forming packets of said audio content and of said data content in said multiplexed signal, with each packet including an identifier.

5. A method for transmitting a multiplexed signal comprising both audio content and data content comprises: multiplexing audio content and data content to form a signal of combined audio and data content; and delivering said signal over a common channel.

6. The method of claim 4 further comprising selecting an SDARS channel as said common channel.

7. A system comprising a module for receiving and selecting a single logical channel comprises: a demultiplexing module for demultiplexing a multiplexed signal comprising audio content and data content; and an output system linked to said demultiplexing module for delivering said audio content and said data content onto separate output paths for a plurality of receivers located at or near the earth's surface.

8. The system of claim 8 further comprising a satellite system for transmitting said signal.

9. The system of claim 7 or claim 8 further comprising: a system comprising a transmission module for outputting combined audio content and data content in a common channel comprises: at least one source for audio content; at least one source for data content; a multiplexer for combining said audio content and said data content into a multiplexed signal on a common channel; and a system for transmitting said signal with combined audio and data content to a plurality of receivers located at or near the earth's surface.

10. The system of claim 1 further comprisiong: at least one source for variable rate audio content; at least one source for data content, comprising information about currently- playing or to-be-played audio.