US20100229206A1 - Space shifting over forward satellite communication channels - Google Patents

Abstract

A method for providing content from a first node to a second node using a satellite communications system includes receiving side information at a subscriber terminal in the satellite communications system. The side information may be transmitted from a gateway to the subscriber terminal via a first communication path that includes a satellite link. The method also includes determining at the subscriber terminal that the side information is associated with first content available at the first node, and determining at the subscriber terminal that second content is available from a source other than the first node. The method also includes generating output content using the second content and the side information. The output content may be substantially the same as the first content. The method also includes providing the output content to the second node via a second communication path that does not include the satellite link.

Description

CROSS-REFERENCES TO RELATED APPLICATIONS
• The present application claims benefit of priority under 35 U.S.C. 119(e) of U.S. Provisional Application No. 61/157,193, filed Mar. 3, 2009, entitled “Source Coding and Space Shifting over Satellite Communication Channels,” the content of which is incorporated herein by reference in its entirety.
• The following U.S. nonprovisional patent applications, including the present application, are being filed concurrently, and the disclosure of the other application is incorporated by reference in the present application in its entirety for all purposes:
• • U.S. Nonprovisional Patent Application No. ______, filed ______ for “Space Shifting Over Return Satellite Communication Channels” (Attorney Docket No. 017018-020410US; Client Reference No. VS-0358-US-2).
  • U.S. Nonprovisional Patent Application No. ______, filed ______ for “Space Shifting Over Forward Satellite Communication Channels” (Attorney Docket No. 017018-020420US; Client Reference No. VS-0358-US-3).
FIELD OF THE INVENTION
• The present invention relates generally to wireless communications. More particularly, the present invention relates to methods, apparatus, and systems for providing content using satellite communications systems.
BACKGROUND
• Satellite communications systems are becoming ubiquitous for transmitting large amounts of content over large geographic regions. In typical satellite communications systems, end users interface with the system through subscriber terminals. The subscriber terminals communicate, via one or more satellites, with one or more gateways. The gateways may process and route data to and from one or more networks according to various network protocols.
• With advances in technology, the demand for transmitting content continues to grow. End users desire increased flexibility and advanced features. As an example, an end user may desire to have a home satellite service, such as satellite television, available at another location while traveling. This may be referred to as space shifting. In one scenario, a satellite television program may be sent to a user's home and then from the home to an alternate location. Such a scenario can increase satellite channel utilization because the program is first sent to the user's home using one satellite link and then to the alternate location using another satellite link. Thus, improved methods and systems are desired that minimize satellite channel utilization while providing content using satellite communications systems.
SUMMARY
• Embodiments of the present invention provide improved methods and systems for providing content in a satellite communications system by utilizing side information. Side information may be anything of use to the satellite communications system, including an identifier of content, a source identifier for content, credentials associated with accessing the content, type of encoding, parameters of encoding, encryption information, authentication, rights management, watermarking directions, timing, and the like. As an example, the side information may be used to identify content, such as audio or video media, that is being sent or is desired to be sent over a satellite link. Once the content has been identified, a source for the content may be found that does not require transmission over the satellite link. For example, a source for the content may be found on a network such as the Internet. The content may be obtained from the source on the network rather than sending the content over the satellite link. As another example, the content may be stored at a gateway or subscriber terminal of the satellite communications system. The content may be retrieved from the gateway or subscriber terminal rather than sending the content over the satellite link. Thus, satellite channel utilization can be minimized while providing content that is equivalent to or substantially the same as that which would have been provided had it been sent entirely over the satellite link.
• In accordance with an embodiment of the invention, a method for providing content from a first node to a second node using a satellite communications system includes receiving side information at a subscriber terminal in the satellite communications system. The side information may be transmitted from a gateway to the subscriber terminal via a first communication path that includes a satellite link. The method also includes determining at the subscriber terminal that the side information is associated with first content available at the first node, and determining at the subscriber terminal that second content is available from a source other than the first node. The method also includes generating output content using the second content and the side information. The output content may be substantially the same as the first content. The method also includes providing the output content to the second node via a second communication path that does not include the satellite link.
• In accordance with another embodiment of the invention, a subscriber terminal for providing content from a first node to a second node using a satellite communications system includes a receiving module configured to receive side information transmitted from a gateway via a first communication path that includes a satellite link. The subscriber terminal also includes a first determining module configured to determine that the side information is associated with first content available at the first node, and a second determining module configured to determine that second content is available from a source other than the first node. The subscriber terminal also includes a generating module configured to generate output content using the second content and the side information. The output content may be substantially the same as the first content. The subscriber terminal also includes a providing module configured to provide the output content to the second node via a second communication path that does not include the satellite link.
• In accordance with yet another embodiment of the invention, a satellite communications system for transmitting content from a first node to a second node includes a source encoder configured to receive first content from the first node and generate side information associated with the first content. The satellite communications system also includes a gateway configured to transmit the side information via a satellite link and a subscriber terminal configured to receive the side information via the satellite link. The subscriber terminal may be configured to determine that the side information is associated with the first content, determine that second content is available from a source other than the first node, generate output content using the second content and the side information, and provide the output content to the second node via a communication path that does not include the satellite link. The output content may be substantially the same as the first content.
• Numerous benefits are achieved using the present invention over conventional techniques. For example, some embodiments according to the present invention provide methods for providing content in a satellite communications system while minimizing satellite channel utilization. Such embodiments can lower transmission costs and reduce transmission times. Depending upon the embodiment, one or more of these benefits may exist. These and other benefits are described throughout the specification and more particularly below.
BRIEF DESCRIPTION OF THE DRAWINGS
• A further understanding of the nature and advantages of the present invention may be realized by reference to the following drawings. In the appended figures, similar components or features may have the same reference label. Further, various components of the same type may be distinguished by following the reference label with a dash and a second label that distinguishes among the similar components. If only the first reference label is used in the specification, the description is applicable to any one of the similar components having the same first reference label irrespective of the second reference label.
• FIG. 1 is a simplified diagram of a exemplary satellite communications system;
• FIG. 2 is a simplified diagram of a satellite communications system configured in accordance with an embodiment of the present invention;
• FIG. 3 is a simplified diagram of a satellite communications system configured for return channel optimization in accordance with an embodiment of the present invention;
• FIG. 4 is a simplified diagram of a satellite communications system configured for return channel optimization in accordance with another embodiment of the present invention;
• FIG. 5 is a simplified diagram of a satellite communications system configured for return channel optimization in accordance with another embodiment of the present invention;
• FIG. 6 is a simplified diagram of a satellite communications system configured for forward channel optimization in accordance with an embodiment of the present invention;
• FIG. 7 is a simplified diagram of a satellite communications system configured for forward channel optimization in accordance with another embodiment of the present invention;
• FIG. 8 is a simplified diagram of a satellite communications system configured for forward channel optimization in accordance with another embodiment of the present invention;
• FIG. 9 is a simplified flowchart illustrating an exemplary method for providing content from a first node to a second node using a satellite communications system in accordance with an embodiment of the present invention; and
• FIG. 10 is a simplified block diagram of an apparatus for providing content from a first node to a second node using a satellite communications system in accordance with an embodiment of the present invention.
DETAILED DESCRIPTION
• The present invention provides methods, apparatus, and systems for providing content in a satellite communications system using side information. The side information may be used, for example, to identify content that is desired to be sent over a satellite link. Using the side information, the content may be found and obtained from a source that does not require transmission over the satellite link. As examples, the content may exist at a satellite gateway or subscriber terminal. Alternatively, the content may be available from a site that is accessible via a computer network. Obtaining the content from these sources, rather than via the satellite link, can minimize satellite channel utilization and reduce transmission times. These and other embodiments of the present invention are described more fully below.
• FIG. 1 is a simplified diagram of an conventionalsatellite communications system100. Thesatellite communications system100 includes anetwork120, such as the Internet, interfaced with agateway115. Thegateway115 is configured to communicate with one ormore subscriber terminals130 via asatellite105. Thegateway115 is sometimes referred to as a hub or ground station.Subscriber terminals130 are sometimes called modems, satellite modems, or user terminals. In accordance with embodiments of the present invention, thesatellite communications system100 may be any type of satellite communications system. For example, thesatellite communications system100 may be a geostationary satellite system or low earth orbit (LEO) satellite system.
• Thenetwork120 may be any type of network and can include, for example, the Internet, an IP network, an intranet, a wide-area network (WAN), a local-area network (LAN), a virtual private network (VPN), the Public Switched Telephone Network (PSTN), and/or any other type of network supporting data communications between devices. Thenetwork120 may include both wired and wireless connections and/or optical links. Many other examples are possible and apparent to those skilled in the art in light of this disclosure. Thenetwork120 may connect thegateway115 with other gateways (not pictured), which may also be in communication with thesatellite105 and that may share information on link conditions and other network metrics.
• Thegateway115 provides an interface between thenetwork120 and thesatellite105. Thegateway115 may be configured to receive data and information directed to one ormore subscriber terminals130. Thegateway115 may be configured to format the data and information along with control signals (e.g., using Adaptive Coding and Modulation (ACM) or Variable Coding and Modulation (VCM)) for delivery via thesatellite105 to therespective subscriber terminal130. Multi-beam satellites may also be used with ACM or VCM. According to the message type and the link condition, ACM or VCM transmitters may utilize codes of various rates and sizes as well as modulations of different orders. For example, high rate codes and high order modulations may be used to take advantage of favorable channel conditions, while low rate codes and low order modulations may be used to ensure error free transmission when channel conditions degrade. Formatting data, information, and control signals may also include spreading techniques resulting in Adaptive Coding, Spreading and Modulation (ACSM).
• Similarly, thegateway115 may also be configured to receive signals from the satellite105 (e.g., from one or more subscriber terminals130) that are directed to a destination in thenetwork120. Thegateway115 may be configured to format the received signals for transmission through thenetwork120.
• A device (not shown) connected to thenetwork120 may, therefore, communicate with one ormore subscriber terminals130 through thegateway115. Data and information, for example IP datagrams, may be sent from the device to thegateway115. Thegateway115 may format a Medium Access Control (MAC) frame in accordance with a physical layer definition for transmission of the data and information to thesatellite105. A variety of physical layer transmission modulation and coding techniques may be used with certain embodiments of the present invention, including those defined by the DVB-S2 and WiMAX standards. As illustrated inFIG. 1, thelink135 from thegateway115 to thesatellite105 may be referred to as thedownstream uplink135.
• Thegateway115 may use anantenna110 to transmit signals to thesatellite105. In one embodiment, theantenna110 comprises a parabolic reflector with high directivity in the direction of the satellite and low directivity in other directions. Theantenna110 may comprise a variety of alternative configurations and include operating features such as high isolation between orthogonal polarizations, high efficiency in the operational frequency bands, and low noise.
• In one embodiment, a geostationary satellite is configured to receive signals from the location of theantenna110 and within the frequency band and specific polarization transmitted. Thesatellite105 may use, for example, a reflector antenna, a lens antenna, an array antenna, an active antenna, or any other mechanism known in the art for reception of such signals. Thesatellite105 may process the signals received from thegateway115 and forward the signals containing the MAC to one or more of thesubscriber terminals130. In one embodiment, thesatellite105 operates in a multi-beam mode, transmitting a number of narrow beams each directed at a different region of the earth. This can allow frequency re-use. With such a multi-beam satellite, there may be any number of different signal switching configurations, allowing signals from asingle gateway115 to be switched between different spot beams. In one embodiment, thesatellite105 may be configured as a “bent pipe” satellite, wherein the satellite may frequency convert the received carrier signals before transmitting the signals to their destination but otherwise perform little or no processing on the contents of the signals. A variety of physical layer transmission modulation and coding techniques may be used by thesatellite105 in accordance with certain embodiments of the invention, including those defined by the DVB-S2 and WiMAX standards. For other embodiments, a number of configurations are possible (e.g., using LEO satellites or using a mesh network instead of a star network), as evident to those skilled in the art.
• The signals transmitted from thesatellite105 may be received by one ormore subscriber terminals130 via arespective subscriber antenna125. In one embodiment, anantenna125 and asubscriber terminal130 together comprise a very small aperture terminal (VSAT), with theantenna125 measuring approximately 0.6 meters in diameter and having approximately 2 watts of power. In other embodiments, a variety of other types ofantennas125 may be used at thesubscriber terminals130 to receive signals from thesatellite105. As shown inFIG. 1, thelink150 from thesatellite105 to thesubscriber terminals130 may be referred to as thedownstream downlink150. Each of thesubscriber terminals130 may comprise a single user terminal or, alternatively, a hub or router that may be coupled to multiple user terminals. Eachsubscriber terminal130 may be connected to consumer premises equipment (CPE)160 comprising, for example, computers, local area networks, Internet appliances, wireless networks, and the like.
• In one embodiment, a Multi-Frequency Time-Division Multiple Access (MF-TDMA) scheme is used forupstream links140,145. This can allow efficient streaming of traffic while maintaining flexibility in allocating capacity among each of thesubscriber terminals130. In this embodiment, a number of frequency channels may be allocated in a fixed or dynamic fashion. A Time Division Multiple Access (TDMA) scheme may be employed in each frequency channel. In this scheme, each frequency channel may be divided into several timeslots that can be assigned to a connection (i.e., a subscriber terminal130). In other embodiments, one or more of theupstream links140,145 may be configured with other schemes, such as Frequency Division Multiple Access (FDMA), Orthogonal Frequency Division Multiple Access (OFDMA), Code Division Multiple Access (CDMA), or any number of hybrid or other schemes as evident to those skilled in the art.
• A subscriber terminal, for example subscriber terminal130-a,may transmit data and information to a destination in thenetwork120 via thesatellite105. The subscriber terminal130-atransmits the signals via the upstream uplink145-ato thesatellite105 using an antenna125-a.The subscriber terminal130-amay transmit the signals according to a variety of physical layer transmission modulation and coding techniques, including those defined by the DVB-S2 and WiMAX standards. In various embodiments, the physical layer techniques may be the same or different for each of thelinks135,140,145,150. As shown inFIG. 1, thelink140 from thesatellite105 to thegateway115 may be referred to as theupstream downlink140.
• FIG. 2 is a simplified diagram of asatellite communications system200 configured in accordance with an embodiment of the present invention. In this example, content, such as audio, video, and the like, may be transmitted from one location to another location via thesatellite communications system200. The content may be encoded by asource encoder265 to provide encoded content to thesubscriber terminal230. The source encoder265 may be part of thesubscriber terminal230 or it may be an independent device. The content may be in analog or digital form, and the encoding step may optionally include transcoding from one coding type to another. Forward error correction coding may be inserted at this stage (e.g., it can be integrated with the source encoding), or it may be inserted later in the transmission path.
• Side information may also be encoded by thesource encoder265. Alternatively, the side information may be output from thesource encoder265 in an uncoded form. The side information may be anything of use to thesatellite communications system200, such as an identifier of the content, a source identifier for the content, credentials associated with accessing the content, type of encoding, parameters of encoding, encryption information, authentication, rights management, watermarking directions, timing information, and the like. In some embodiments, the side information may be used in transmitting and/or decoding the encoded content. The side information may be generated by thesource encoder265 or provided to thesource encoder265 by another device (not shown) within thesatellite communications system200. The side information output from thesource encoder265 may be the original side information, some representation of the original side information, and/or internally generated side information.
• The encoded content and the side information that are output from thesource encoder265 are modulated by thesubscriber terminal230 and transmitted oversatellite links240,245 to agateway215. Although represented by two separate signals in this figure, both types of data (i.e., the encoded content and the side information) may be multiplexed onto a single signal for transmission. Note that any bi-directional control and status messages necessary to support such communication are not shown for clarity.
• As illustrated in this example, thegateway215 may send the encoded content and the side information to anoutput decoder270 using anetwork220. Theoutput decoder270 may use the side information and the encoded content to create output content that is provided directly to an end user. Alternatively, thegateway215 may send the encoded content and the side information to an end user via another subscriber terminal (not shown) using other satellite links, where the side information and the encoded content are used to create the output content for an end user. One of ordinary skill in the art would recognize many variations, modifications, and alternatives.
• FIG. 3 is a simplified diagram of asatellite communications system300 configured for return channel optimization in accordance with an embodiment of the present invention. In this example, first content is encoded bysource encoder365 to provide encoded content. Side information may also be encoded by thesource encoder365. In this example, only the side information is modulated bysubscriber terminal330 and transmitted oversatellite links340,345 to agateway315. Thegateway315 provides the side information to agateway encoder380 that may be part of thegateway315 or an independent device. In this example, thegateway encoder380 has access to second content from a source other than thesubscriber terminal330. For example, the second content may be stored at thegateway315 or thegateway encoder380. Alternatively, the second content may be available from a source that is accessible via anetwork320. In some embodiments, the second content may be a similar version to or a copy of the first content. The second content may be in coded or uncoded form.
• As illustrated inFIG. 3, thegateway encoder380 may use the side information and the second content to provide encoded content to anoutput decoder370 via thenetwork320. Theoutput decoder370 may use the side information and the encoded content to create output content that is provided directly to an end user. Alternatively, thegateway315 may send the encoded content and the side information to an end user via another subscriber terminal (not shown) using other satellite links, where the side information and the encoded content are used to create the output content for an end user. In either scenario, output content is provided to the end user that is equivalent to or substantially the same as that which would have been provided had the encoded content been transmitted over the satellite links340,345.
• FIG. 4 is a simplified diagram of asatellite communications system400 configured for return channel optimization in accordance with another embodiment of the present invention. In this example, encoded content and side information are provided from asource encoder465 to asubscriber terminal430. The encoded content may be partially transmitted oversatellite links440,445 (indicated by the dashed lines inFIG. 4). For example, thesubscriber terminal430 may start transmitting the complete stream including the encoded content and the side information to agateway415. The encoded content may be, for example, streaming media or downloadable content. Thegateway415 and/or agateway encoder480 may perform an analysis of the encoded content and/or the side information and determine that the encoded content can be obtained without transmitting the entire encoded content over the satellite links440,445. For example, the encoded content may be generated using second content stored at thegateway415 or thegateway encoder480. The second content may have been stored at thegateway415 or thegateway encoder480 during a previous broadcast or transmission. Thegateway415 may direct thesubscriber terminal430 to limit its broadcast to that portion of the side information that is necessary for thegateway encoder480 to create the encoded content. In one embodiment, the encoded content may be provided to anoutput decoder470 via anetwork420. Theoutput decoder470 may decode the encoded content and provide output content directly to an end user. Alternatively, thegateway415 may send the encoded content to an end user via another subscriber terminal (not shown) using other satellite links, where the encoded content is decoded to provide output content to an end user. Thus, return channel utilization can be minimized while the output content provided to the end user is equivalent to or substantially the same as that which would have been generated had the entire encoded content been transmitted over the satellite links440,445.
• FIG. 4 shows the side information being generated at thesource encoder465. Alternatively, the side information may be provided to thesource encoder465 by another device, either before or after source encoding.FIG. 4 also shows that only the encoded content is output from thegateway encoder480. In some embodiments, however, both the encoded content and the side information may be output from thegateway encoder480.
• FIG. 5 is a simplified diagram of a satellite communications system500 configured for return channel optimization in accordance with another embodiment of the present invention. In this example, first content is provided to source encoder565, and side information is generated based on the first content and provided to a subscriber terminal530. The subscriber terminal530 transmits the side information over satellite links540,545 to a gateway515. In this example, the side information is used by the gateway515 and/or a gateway encoder580 to identify second content at another source that is accessible via a network520. The gateway515 or the gateway encoder580 may have the second content sent directly to the output decoder570 to provide output content to an end user. Alternatively, the second content may be obtained by the gateway515 and/or the gateway encoder580 and sent to the output decoder570. As would be appreciated by one of ordinary skill in the art, the second content may be available in coded or uncoded form, and thus the gateway encoder580 may encode or transcode the second content as necessary. In some embodiments, rather than providing the second content to the output decoder570, thegateway415 may send the second content to an end user via another subscriber terminal (not shown) using other satellite links. Thus, return channel utilization can be minimized while the output content provided to the end user is equivalent to or substantially the same as that which would have been generated had the entire encoded content been transmitted over the satellite links540,545. One of ordinary skill in the art would recognize many variations, modifications, and alternatives.
• Similar methods can be used to optimize a forward satellite channel in accordance with various embodiments of the present invention. Such embodiments may be used independent of or in conjunction with the embodiments described above.FIG. 6 is a simplified diagram of one example of such a system. In this example, encoded content and side information may be generated from first content that is provided to asource encoder690, and the side information may be provided to agateway615 via anetwork620. Alternatively, the encoded content may be provided to agateway decoder685 via thenetwork620, and side information may be generated at thegateway decoder685. Thegateway decoder685 may also be used for transcoding. For example, if the first content is a high-quality live video feed of the bicycle Race Across America (RAAM), and an end user has subscribed to a low quality webcast feed, then transcoding may be performed at thegateway decoder685 to generate the side information necessary to provide a low-resolution representation of the video feed. The side information, either from thesource encoder690 or thegateway decoder685, may be transmitted oversatellite links635,650 to asubscriber terminal630.
• At thesubscriber terminal630, some alternate representation of the original first content, for example a similar version or a copy of the first content, may be available. The second content may be available via the same communications system provider as the first content or via another provider such as a broadcaster. Continuing with the above example, the RAAM video feed may be available to an end user through a satellite television broadcast system. The side information, which in this case may include at least an indication of the subscribed quality of the video feed, is provided to anoutput decoder695. Theoutput decoder695 may use the side information to generate the output content for the end user. Alternatively, an encoder/transcoder696 may be used if the second content is in a format that is different from that used by theoutput decoder695. Thus, the output content provided to the end user may be equivalent to or substantially the same as that which would have resulted from the transmission of the entire encoded content over the satellite links635,650.
• FIG. 7 is a simplified diagram of asatellite communications system700 configured for forward channel optimization in accordance with another embodiment of the present invention. In this example, first content is provided to asource encoder790. Thesource encoder790 generates encoded content that is delivered to angateway decoder785 via anetwork720. Thegateway decoder785 uses the encoded content to generate side information that is modulated and transmitted by agateway715 oversatellite links735,750 to asubscriber terminal730. The side information may be used by thesubscriber terminal730 and/or anoutput decoder795 to identify second content. For example, the second content may be available from thesubscriber terminal730 or theoutput decoder795. Alternatively, the second content may be available from another device that is in communication with thesubscriber terminal730 or theoutput decoder795. The second content may be provided to theoutput decoder795 to provide output content for an end user. If the second content is encoded, theoutput decoder795 may decode the second content. Thus, the output content provided to the end user may be equivalent to or substantially the same as that which would have resulted from transmission of the entire encoded content over the satellite links735,750.
• FIG. 8 is a simplified diagram of asatellite communications system800 configured for forward channel optimization in accordance with another embodiment of the present invention. In this example, first content is provided to asource encoder890. Thesource encoder890 generates encoded content that is delivered to agateway decoder885 via anetwork820. Thegateway decoder885 generates side information that is modulated and transmitted by agateway815 oversatellite links835,850 to asubscriber terminal830. At thesubscriber terminal830, the side information is used to identify second content. In this example, the second content is available via thenetwork820. The second content may be provided to theoutput decoder895 to provide output content for an end user. If the second content is encoded, theoutput decoder895 may decode the second content. Thus, similar to the previous examples, the output content provided to the end user may be equivalent to or substantially the same as that which would have resulted from the transmission of the entire encoded content over the satellite links835,850.
• Similar to the above examples, some embodiments of the present invention may include identifying encoded content that is transmitted over a satellite link. As an example, digital content in a frame or series of frames may be identified or matched with content in accordance with known techniques. A portion of the encoded content may be used to identify content that is stored at a gateway or subscriber terminal or that is available from a source that is accessible via a computer network. In these embodiments, a portion of the encoded content may be used to identify and/or locate the content, and the content may be provided to an end user without transmitting the entire encoded content over the satellite link.
• FIG. 9 is a simplified flowchart illustrating an exemplary method for providing content from a first node to a second node using a satellite communications system in accordance with an embodiment of the present invention. The method includes receiving side information at a communication device, where the side information is transmitted from the first node to the communication device via a first communication path that includes a satellite link (902). The communication device may be a gateway, a subscriber terminal, a decoder, an encoder, or the like. The method also includes determining that the side information is associated with first content available at the first node (904). The first content may be source content. The side information may be used, for example, to identify the first content or to generate output content that is substantially the same as the first content. In some embodiments, the side information is generated using the first content.
• The method also includes determining that second content is available from a source other than the first node (906). The second content may be a copy of or a similar version of the first, or source, content. The second content may be available at a gateway, a subscriber terminal, or another device in the satellite communications system. Alternatively, the second content may be available from a source that is accessible via a computer network. The method also includes generating output content using the second content and the side information (908). The output content may be substantially the same as the first content. The method also includes providing the output content to the second node via a communication path that does not include the satellite link (910). The output content may be equivalent to or substantially the same as that which would have resulted from the transmission of the first content over the satellite link.
• It should be appreciated that the specific steps illustrated inFIG. 9 provide a particular method for providing content from a first node to a second node using a satellite communications system. In some embodiments the steps outlined above may be continuously repeated by system software. Also, other sequences of steps may be performed according to alternative embodiments. For example, the steps outlined above may be performed in a different order. Moreover, the individual steps illustrated inFIG. 9 may include multiple sub-steps that may be performed in various sequences as appropriate to the individual step. Furthermore, additional steps may be added or removed depending on the particular application. One of ordinary skill in the art would recognize many variations, modifications, and alternatives.
• FIG. 10 is a simplified block diagram of anapparatus1000 for providing content from a first node to a second node using a satellite communications system in accordance with various embodiments of the present invention. The apparatus may be, for example, a gateway, a subscriber terminal, or a similar device in a satellite communications system. The apparatus includes areceiving module1002. Thereceiving module1002 may be configured to receive side information transmitted from the first node via a first communications path that includes a satellite link. The apparatus also includes a first determiningmodule1004. The first determiningmodule1004 may be configured to determine that the side information is associated with first content available at the first node. The first content may be, for example, source content. The apparatus also includes a second determiningmodule1006. The second determining module may be configured to determine that second content is available from a source other than the first node. For example, the second content may be a copy of or similar version of the first content. The apparatus also includes agenerating module1008. Thegenerating module1008 may be configured to generate output content using the second content and the side information. The output content may be substantially the same as the first content. The apparatus also includes a providingmodule1010. The providingmodule1010 may be configured to provide the output content to the second node via a second communications path that does not include the satellite link.
• While a satellite communications system has been used above to illustrate various aspects of the present invention, it should be noted that the principles set forth herein are applicable to a number of other wireless systems as well (e.g., other peer-to-peer wired or wireless links). As an example, side information may be utilized in a cellular communications system in a manner similar to that described above. The side information may be used, for example, to identify content that is being sent, or that is desired to be sent, over a cellular channel. Using the side information, content may be found and obtained from a source that does not require transmission over the cellular channel or that can be transmitted over a lower cost cellular channel. As examples, the content may exist at a cellular gateway or a user device such as a cellular phone. Alternatively, the content may be available from a site that is accessible via a wired or wireless link over a computer network. Obtaining the content from one of these sources, rather than via the cellular channel, can minimize cellular channel utilization and reduce transmission costs. One of ordinary skill in the art would recognize many variations, modifications, and alternatives.
• It should be noted that the methods, apparatus, and systems discussed above are provided merely as examples. Various embodiments may omit, substitute, or add various procedures or components as appropriate. For instance, it should be appreciated that features described with respect to certain embodiments may be combined in various other embodiments. Furthermore, embodiments may be implemented by hardware, software, firmware, middleware, microcode, hardware description languages, or any combination thereof. When implemented in software, firmware, middleware, or microcode, the program code or code segments to perform the necessary tasks may be stored in a computer-readable medium such as a storage medium. Processors may perform the necessary tasks. The term “computer-readable medium” includes, but is not limited to, portable or fixed storage devices, optical storage devices, wireless channels, a sim card, other smart cards, and various other mediums capable of storing, containing, or carrying instructions or data.
• Having described several embodiments, it will be recognized by those of skill in the art that various modifications, alternative constructions, and equivalents may be used without departing from the spirit of the invention. For example, the above elements may merely be a component of a larger system, wherein other rules may take precedence over or otherwise modify the application of the invention. Also, a number of steps may be undertaken before, during, or after the above elements are considered. Accordingly, the above description should not be taken as limiting the scope of the invention.

Claims (20)

1. A method for providing content from a first node to a second node using a satellite communications system, the method comprising:

receiving side information at a subscriber terminal in the satellite communications system, the side information being transmitted from a gateway to the subscriber terminal via a first communication path that includes a satellite link;

determining at the subscriber terminal that the side information is associated with first content available at the first node;

determining at the subscriber terminal that second content is available from a source other than the first node;

generating output content using the second content and the side information, the output content being substantially the same as the first content; and

providing the output content to the second node via a second communication path that does not include the satellite link.

2. The method ofclaim 1 wherein providing the output content from the source to the second node comprises:

obtaining at the subscriber terminal the second content from the source; and

transmitting the output content from the subscriber terminal to the second node.

3. The method ofclaim 1 wherein the first content is streaming media.

4. The method ofclaim 1 wherein the first content is downloadable media.

5. The method ofclaim 1 wherein the output content is provided to the second node via a computer network.

6. The method ofclaim 1 wherein the subscriber terminal comprises at least one of an encoder or a decoder.

7. The method ofclaim 1 wherein the subscriber terminal is coupled to the source via a computer network.

8. The method ofclaim 1 wherein the second content is stored at the subscriber terminal.

9. The method ofclaim 1 wherein the side information comprises an identifier of the first content.

10. The method ofclaim 1 wherein the second content is substantially the same as the output content.

11. The method ofclaim 1 wherein the first content comprises a video feed at a first resolution, and the second content comprises the video feed at a second resolution different from the first resolution, and generating the output content includes generating the video feed at the first resolution.

12. A subscriber terminal for providing content from a first node to a second node using a satellite communications system, comprising:

a receiving module configured to receive side information transmitted from a gateway via a first communication path that includes a satellite link;

a first determining module configured to determine that the side information is associated with first content available at the first node;

a second determining module configured to determine that second content is available from a source other than the first node;

a generating module configured to generate output content using the second content and the side information, where the output content is substantially the same as the first content; and

a providing module configured to provide the output content to the second node via a second communication path that does not include the satellite link.

13. The subscriber terminal ofclaim 12 wherein the providing module comprises:

an obtaining module configured to obtain the second content from the source; and

a transmitting module configured to transmit the output content to the second node.

14. The subscriber terminal ofclaim 12 wherein the output content is provided to the second node via a computer network.

15. The subscriber terminal ofclaim 12 wherein the second content is stored at the subscriber terminal.

16. The subscriber terminal ofclaim 12 wherein the subscriber terminal is coupled to the source via a computer network.

17. A satellite communications system for transmitting content from a first node to a second node, comprising:

a source encoder configured to receive first content from the first node and generate side information associated with the first content;

a gateway configured to transmit the side information via a satellite link; and

a subscriber terminal configured to receive the side information via the satellite link and configured to:

determine that the side information is associated with the first content;

determine that second content is available from a source other than the first node;

generate output content using the second content and the side information, where the output content is substantially the same as the first content; and

provide the output content to the second node via a communication path that does not include the satellite link.

18. The satellite communications system ofclaim 17 wherein the subscriber is coupled to the source via a computer network.

19. The satellite communications system ofclaim 17 wherein the second content is stored at the subscriber terminal.

20. The satellite communications system ofclaim 17 wherein the subscriber terminal is configured to provide the output content to the second node via a computer network.

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