Piggyback networks

• US 8,483,240 B2
• Filed: 12/19/2006
• Issued: 07/09/2013
• Est. Priority Date: 12/19/2006
• Status: Active Grant

• Current Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Original Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Inventors: Ross, John Anderson Fergus, Hartman, Michael James, Hershey, John Erik, Tomlinson, Harold Woodruff Jr.
• Primary Examiner(s): Rinehart, Mark
• Assistant Examiner(s): ANWAR, MOHAMMAD S
• Application Number:
  US11/640,994
• Publication Number:
  US 20080144666A1
• Time in Patent Office: 2,394 Days
• Field of Search: 370/477, 370/473, 370/479
• US Class Current: 370/477
• CPC Class Codes: H04L 1/004 by using forward error control H04L1/0618 takes precedence; coding, decoding or code conversion, for error detection or correction H03M13/00
• CPC Class Codes: H04L 1/0041 Arrangements at the transmitter end
• CPC Class Codes: H04L 1/0048 in conjunction with detection of multiuser or interfering signals, e.g. iteration between CDMA or MIMO detector and FEC decoder for spatial equalizer H04L25/03286
• CPC Class Codes: H04L 2001/0093 Point-to-multipoint
• CPC Class Codes: H04L 27/3488 Multiresolution systems
• CPC Class Codes: H04L 5/04 the signals being represented by different amplitudes or polarities, e.g. quadriplex

Abstract

Systems and/or methods for relaying messages between nodes in a network (e.g. a wireless network) are provided. In accordance with certain exemplary embodiments, substantially simultaneous communications between nodes may be accomplished. At least one secondary message may be piggybacked onto a primary message. Messages in the network may be queued and sent from a transmitter to at least one receiver based at least in part on the signal-to-noise ratio(s) of the receiver nodes with respect to the transmitter. The queuing of the messages may be performed in dependence on a link set that indicates which messages are capable of piggyback communications. Thus, it may be possible to realize a network that reduces collision problems, reduces delays in communications, and/or increases throughput.

Claims

1. A method of relaying messages over a communications network, the method comprising:

identifying a primary message and at least one secondary message to be communicated from a transmitter, the primary message being designated for a first receiver node and the at least one secondary message being designated for a second receiver node that is geographically separated from the first receiver node;

piggybacking the at least one secondary message onto the primary message to form a piggybacked message in response to a signal indicating that piggybacking of the at least one secondary message onto the primary message is possible, the signal being based at least in part on a characteristic of the first receiver node and the second receiver node relative to the transmitter node; and

,

transmitting the primary message and the piggybacked message at a same power level, wherein the piggybacking is further practiced by;

scaling the at least one secondary message by a scale factor to form a scaled message; and

,

summing the primary message and the scaled message.

2. The method of claim 1, further comprising maintaining a list storing the characteristic corresponding to each link between the nodes in the network.

3. The method of claim 2, wherein the list is static.

4. The method of claim 2, wherein the list is maintained based on feedback between the nodes.

5. The method of claim 2, wherein the signal is further based on the list.

6. The method of claim 1, wherein the characteristic of the first receiver node is SNR relative to the transmitter node, and the characteristic of the second receiver node is SNR relative to the transmitter node.

7. The method of claim 1, further comprising determining the scale factor based at least in part on a SNR of the first receiver node relative to the transmitter node and a SNR of the second receiver node relative to the transmitter node.

8. The method of claim 1, wherein the step of identifying a primary message and at least one secondary message further comprises searching a message queue for a most-forward packet capable of piggybacking and/or being piggybacked.

9. A method of relaying messages over a communications network, the method comprising:

identifying a transmitter node and at least two receiver nodes that are geographically separated from each other;

identifying a primary message and at least one secondary message to be transmitted from the transmitter node, each message being stored in a message queue, and each message including packets of data;

determining a next packet of the primary message to be transmitted;

identifying possible partner links between nodes in the network that are capable of supporting piggybacking for the next packet;

generating a full message by piggybacking a packet of each of secondary message onto the next packet of the primary message in response to a signal indicating piggybacking is possible; and

,

transmitting the full message at a same power level,

wherein the signal is based at least in part on relative signal-to-noise ratios of the at least two receiver nodes with respect to the transmitter node, wherein the piggybacking of a packet of each secondary message onto the next packet of the primary message further comprises;

for each secondary message, identifying a piggyback packet by searching the message queue for the most forward secondary packet that uses a partner link;

scaling each piggyback packet according to link signal-to-noise ratio; and

,

combining the next packet and each piggyback packet.

10. The method of claim 9, wherein the scaling is based at least in part on the signal-to-noise ratios of the receivers relative to the transmitter.

11. The method of claim 9, further comprising estimating a link signal-to-noise ratio for each link between nodes in the network.

12. The method of claim 11, further comprising estimating the link signal-to-noise ratio for each partner link based at least in part on substantially constant feedback between nodes.

13. The method of claim 12, wherein the estimates are made on-the-fly.

14. A system for relaying messages over a communications network, comprising:

a transmitter node and at least two receiver nodes, the transmitter node and the at least two receiver nodes being configured to communicate at least a primary message and at least one secondary message therebetween and wherein said at least two receiver nodes are geographically separated from each other;

wherein the primary message and the at least one secondary message are to be sent from the transmitter node to the at least two receiver nodes based at least in part on a comparison of signal-to-noise ratios of the at least two receiver nodes relative to the transmitter node,

wherein the primary message and the at least one secondary message are to be piggybacked based at least in part on the comparison and transmitted at the same power level, and

wherein each node comprises a piggybacking mechanism, the piggybacking mechanism including;

a scaler operable to scale the at least one secondary message to form a scaled message; and

,

a summer operable to sum the scaled message and the primary message.

15. The system of claim 14, further comprising a message queue associated with a node operable to store messages to be communicated.

16. The system of claim 15, further comprising a list of SNRs for each link between nodes in the network.

17. The system of claim 16, wherein the nodes are operable to update the list.

18. The system of claim 16, further comprising a list including comparisons for each link between nodes in the network.

19. The system of claim 15, wherein the message queue is operable to output a most-forward packet capable of piggybacking and/or being piggybacked.

20. The system of claim 14, wherein the primary message and the at least one secondary message are piggybacked if the comparison indicates a substantial SNR for the at least two receiver nodes relative to the transmitter node.

21. The system of claim 20, wherein the substantial SNR is 100:

1.

22. A system for relaying messages over a communications network, comprising:

means for identifying a primary message and at least one secondary message to be communicated from a transmitter, the primary message being designated for a first receiver node and the at least one secondary message being designated for a second receiver node, wherein said first and second receiver nodes are geographically separated from each other;

means for piggybacking the at least one secondary message onto the primary message to form a piggybacked message in response to a signal indicating that piggybacking of the at least one secondary message onto the primary message is possible, the signal being based at least in part on a characteristic of the first receiver node and the second receiver node relative to the transmitter node;

the means for piggybacking cooperating with a scaler operable to scale the at least one secondary message to form a scaled message and a summer operable to sum the scaled message and the primary message, in piggybacking the at least one secondary message onto the primary message,

a transmitter configured to transmit the primary message and the piggybacked message at a same power level.

23. A method of relaying messages over a communications network, the method comprising:

identifying a first message to be communicated by a first antenna of a transmitter node and a secondary message to be communicated by a second antenna of the transmitter node, the first antenna and the second antenna having substantially distinctive antenna apertures;

communicating substantially non-orthogonally at substantially the same time over substantially the same channel the first message and the second message using the first antenna and the second antenna in dependence on a breakpoint difference between near and far field regions of the network;

receiving the first message and the second message by a receiver node having two antennas with distinct apertures; and

,

scaling and separating the messages in dependence on the antenna apertures; and

receiving the second message by a second receiver node geographically separated from the first receiver node.

24. The method of claim 23, wherein the first antenna has a signal drop-off rate of approximately 1/r² and the second antenna has a signal drop-off rate of approximately 1/r³.

25. A computer implemented method of relaying messages over a communications network, the method comprising:

using at least one computer having at least one processor for performing the following;

identifying a primary message and at least one secondary message to be communicated from at least one transmitter node, the primary message being designated for one or more first receiver nodes and the at least one secondary message being designated for one or more second receiver nodes, the one or more first receiver nodes being geographically separated from the one or more second receiver nodes;

scaling the at least one secondary message by a scale factor to form a scaled message; and

,

summing the primary message and the scaled message; and

piggybacking the scaled message onto the primary message to form a substantially non-orthogonal piggybacked message such that the primary message and the at least one secondary message are capable of being transmitted at substantially the same time over substantially the same channel and at a same power level,

wherein the piggybacking is performed in dependence on predefined SNRs between the at least one transmitter node, and the one or more first receiver nodes and the one or more second receiver nodes.

26. The method of claim 25, further comprising when a receiver node receives a message, processing the message in dependence on whether the message is a piggybacked message.

27. The method of claim 25, wherein the piggybacked message includes multicast information.

28. A system for relaying messages over a communications network, comprising:

a transmitter node and at least two receiver nodes, the transmitter node and the at least two receiver nodes being configured to communicate at least a primary message and at least one secondary message therebetween and wherein the at least two receiver nodes are geographically separated from each other;

wherein the primary message and the at least one secondary message are piggybacked to form a substantially non-orthogonal piggybacked message, such that the primary message and the at least one secondary message are capable of being transmitted at substantially the same time over substantially the same channel and at a same power level, the at least one secondary message being scaled by a scale factor to form a scaled message that is summed with the primary message as a part of the piggybacking,

wherein the primary message and the at least one secondary message are piggybacked in dependence on predefined SNRs between the transmitter node and the at least two receiver nodes.

29. The system of claim 28, wherein each receiver node is further operable to process a received message in dependence on whether the received message is a piggybacked message.

30. The system of claim 28, wherein the primary message is broadcast for one or more receiver nodes.

31. The system of claim 28, wherein the piggybacked message includes multicast information.

32. A transmitter node comprising an encoder processor for preparing a message to be relayed through a network of nodes, the encoder processor comprising a piggybacking module configured to generate a piggybacked message by piggybacking at least one secondary message designated for at least one second receiver node onto a primary message designated for at least one first receiver node based at least in part on a comparison of signal-to-noise ratios of the receiver nodes relative to the transmitter node, wherein the receiver nodes are geographically separated from each other and wherein the piggybacked message is transmitted at one power level, the piggybacking being performed by scaling the at least one secondary message by a scale factor to form a scaled message and summing together the primary message and the scaled message.

33. The transmitter node of claim 32, further comprising a transmitting module for transmitting at least one of the piggybacked message, the primary message, and the at least one secondary message based at least in part on the comparison.

34. A transmitter node comprising an encoder processor for preparing a message to be relayed over a communications network, the encoder processor comprising a piggybacking module configured to generate a piggybacked message by piggybacking at least one secondary message designated for at least one second receiver node onto a primary message designated for at least one first receiver node, the piggybacked message being substantially non-orthogonal, such that the primary message and the at least one secondary message are capable of being transmitted at substantially the same time over substantially the same channel and at a same power level,

wherein the receiver nodes are geographically separated from each other, and

wherein the primary message and the at least one secondary message are piggybacked in dependence on a comparison of signal-to-noise ratios between the transmitter node and the receiver nodes, the node further comprising:

a scaler operable to scale the at least one secondary message to form a scaled message; and

,

a summer operable to sum the scaled message and the primary message, in connection with the piggybacking.

35. A receiver node comprising a decoder processor for processing a message received from a transmitter node, the decoder processor comprising a separating module configured to separate a primary message designated for at least one first receiver node from at least one secondary message designated for at least one second receiver node based at least in part on a comparison of signal-to-noise ratios of the receiver nodes relative to the transmitter node, the primary message and the at least one secondary message being included in a received piggybacked message, wherein the receiver nodes are geographically separated from each other, the primary message and the piggybacked message having been transmitted at a same power level, the at least one secondary message having been scaled by a scale factor to form a scaled message, the scaled message having been summed together with the primary message.

36. The receiver node of claim 35, further comprising a switch configured to control decoding and/or piggybacking.

37. A receiver node comprising a decoder processor for processing a message relayed over a communications network, the decoder processor comprising a separating module configured to separate a substantially non-orthogonal piggybacked message by separating at least one secondary message designated for at least one second receiver node from a primary message designated for at least one first receiver node, wherein the receiver nodes are geographically separated from each other, the primary message and the piggybacked message having been transmitted at a same power level, the at least one secondary message having been scaled by a scale factor to form a scaled message, the scaled message having been summed together with the primary message.

38. The receiver node of claim 37, further comprising a switch configured to control decoding and/or piggybacking.