Opportunistic progressive encoding
Methods, systems, and devices are described for communicating data from multiple data terminals to an aggregator terminal over a communication link having changing link conditions. In some embodiments, source data is received at multiple data terminals, each in communication with an aggregator terminal over a communication link. For example, during a live newscast, one mobile camera may receive live video of an event from a first position while another mobile camera receives live video of the event from a second position. For various reasons (e.g., as the cameras move) each communication link may experience independently changing link conditions. Each data terminal encodes the source data (or store source data for later encoding) as a function of its respective link conditions, and transmits encoded source data over its respective communication link to the aggregator terminal.
1. A link-aware data system for communicating data between multiple data terminals and an aggregator terminal over communication links with changing link conditions, the system comprising:
an aggregator terminal, adapted to receive data over a plurality of communication links and aggregate the data into an aggregate dataset; and
a plurality of data terminals remote from the aggregator terminal, each communicatively coupled with the aggregator terminal via at least a common one of the plurality of communication links, and comprising:
a receiver unit adapted to receive source data from a data source;
a link awareness unit, executed by one or more processors, adapted to generate a link condition defining a condition of the at least one of the plurality of communication links;
an adaptive coder unit, communicatively coupled with the receiver unit and the link awareness unit, and adapted to encode the source data into an encoded data signal as a function of the link condition; and
a transceiver unit, communicatively coupled with the adaptive coder unit, and adapted to transmit the encoded data signal over the at least one of the plurality of communication links,
wherein the aggregator terminal is adapted to receive data by receiving the encoded data signal over the at least one of the plurality of communication links.
2. The system of claim 1 , wherein the aggregator terminal is further adapted to affect operation of at least some of the plurality of data terminals by transmitting a control signal to the at least some of the plurality of data terminals over at least one of the plurality of communication links.
3. The system of claim 2 , wherein the at least some of the plurality of data terminals is adapted to receive the source data from the data source as a function of the control signal.
4. The system of claim 2 , wherein the at least some of the plurality of data terminals is adapted to encode the source data into an encoded data signal as a function of the control signal.
5. The system of claim 1 , wherein the common one of the plurality of communication links comprises a satellite communication link.
6. A link-aware data system for receiving source data and transmitting the source data over a communication link having changing link conditions, the system comprising:
a receiver unit adapted to receive the source data from a data source;
a link awareness unit, executed by one or more processors, adapted to generate a link condition defining a condition of the communication link;
an adaptive coder unit, communicatively coupled with the receiver unit and the link awareness unit, and adapted to encode the source data into an encoded data signal as a function of the link condition;
a transceiver unit, communicatively coupled with the adaptive coder unit, and adapted to transmit the encoded data signal over the communication link;
a buffer unit, communicatively coupled with the adaptive coder unit, and adapted to store a first representation dataset representing the source data;
wherein the adaptive coder unit is further adapted to pre-code at least a portion of the source data using a first pre-coding scheme to generate a second representation dataset, decodable to provide a set of first-level playback data representing the source data, the second representation dataset being different from the first representation dataset.
7. The system of claim 6 , wherein the first representation dataset comprises at least a portion of the source data.
8. The system of claim 7 ,
wherein the adaptive coder unit is further adapted to pre-code at least a portion of the source data using a second pre-coding scheme to generate a set of representation data, decodable in combination with the second representation dataset to provide a set of second-level playback data representing the set of source data,
wherein the first representation dataset comprises the set of representation data.
9. The system of claim 8 , wherein the first-level playback data provides a lower resolution representation of the source data than the second-level playback data.
10. The system of claim 8 , wherein the adaptive coder unit is further adapted to:
receive a portion of the representation dataset from the buffer; and
pre-code the portion of the representation dataset using a third pre-coding scheme to regenerate the second representation dataset.
11. The system of claim 8 , wherein the transceiver unit is further communicatively coupled with the buffer unit and is further adapted to:
transmit the first representation dataset over the communication link when the link condition substantially matches a first link condition profile; and
transmit the second representation dataset over the communication link when the link condition substantially matches a second link condition profile.
12. The system of claim 8 ,
wherein the adaptive coder unit is further adapted to associate the first representation dataset with a first coding and modulation scheme and to associate the second representation dataset with a second coding and modulation scheme,
wherein the first coding and modulation scheme is of a higher order than the second coding and modulation scheme, and
wherein the transceiver unit is further adapted to:
transmit the first set of representation data over the communication link using the first coding and modulation scheme; and
transmit the second set of representation data over the communication link using the second coding and modulation scheme.
13. The system of claim 12 , wherein the adaptive coder unit is further adapted to determine at least one of the first coding and modulation scheme or the second coding and modulation scheme as a function of the link condition.
14. The system of claim 6 , wherein the link awareness unit is communicatively coupled with the communication link and is further adapted to generate the link condition by testing a present condition of the communication link.
15. The system of claim 6 , wherein the link awareness unit is adapted to generate the link condition as a function of at least one of a signal-to-noise ratio of the communication link, a bandwidth of the communication link, or a priority rating for the source data.
16. The system of claim 6 , wherein the transceiver unit is adapted to transmit the encoded data signal over the communication link to an aggregator system having data aggregation capabilities, and the link condition relates at least in part to the data aggregating capabilities.
17. The system of claim 6 ,
wherein the transceiver unit is adapted to transmit the encoded data signal over the communication link to an aggregator system and to receive a command signal from the aggregator system, and
wherein the link awareness unit is adapted to generate the link condition as a function of the command signal.
18. The system of claim 5 , wherein the plurality of data terminals are provided at corresponding locations of subscribers to the satellite communication link.