Dynamic link assignment in a communication system

• US 7,961,666 B2
• Filed: 03/08/2010
• Issued: 06/14/2011
• Est. Priority Date: 07/24/2000
• Status: Expired due to Term

• Current Assignee: ViaSat Incorporated
• Original Assignee: ViaSat Incorporated
• Inventors: Vanderaar, Mark J., Nimon, Matthew D., Thesling, William H.
• Primary Examiner(s): Bost; Dwayne D
• Assistant Examiner(s): Mehra; Inder P
• Application Number:
  US12/719,643
• Publication Number:
  US 20100157931A1
• Time in Patent Office: 463 Days
• Field of Search: 370315-316, 370/352, 370/401, 370/466, 370/469, 370/317, 370/350, 370/392, 455/12.1, 455/69, 455/427, 455/205
• US Class Current: 370/317
• CPC Class Codes: H04L 1/0003 by switching between different modulation schemes
• CPC Class Codes: H04L 1/0009 by adapting the channel coding H04L1/1812 takes precedence
• CPC Class Codes: H04L 1/0025 Transmission of mode-switching indication
• CPC Class Codes: H04L 1/0026 Transmission of channel quality indication
• CPC Class Codes: H04L 2001/0093 Point-to-multipoint
• CPC Class Codes: H04L 27/2601 Multicarrier modulation systems
• CPC Class Codes: H04L 27/2602 Signal structure
• CPC Class Codes: H04L 27/2657 Carrier synchronisation
• CPC Class Codes: H04L 5/0007 the frequencies being orthogonal, e.g. OFDM(A), DMT
• CPC Class Codes: H04L 5/003 Arrangements for allocating sub-channels of the transmission path
• CPC Class Codes: H04L 5/0048 Allocation of pilot signals, i.e. of signals known to the receiver
• CPC Class Codes: H04L 5/0053 Allocation of signaling, i.e. of overhead other than pilot signals

Abstract

An architecture for the dynamic assignment of links in a multi-user communication system. A plurality of information channels are provided in a forward communication link of the communication system for carrying channel information of the plurality of information channels from a transmitter to a plurality of corresponding receiving devices. The channel information in corresponding select ones of the plurality of information channels is varied dynamically in response to link conditions of the associated receiving devices to more efficiently utilize the channel bandwidth.

Claims

1. A method for transmitting one or more packets via a satellite to a selected user terminal of a plurality of user terminals, the method comprising:

receiving information corresponding to a reception quality from the satellite for the selected user terminal, the information transmitted from the selected user terminal;

utilizing the received information to identify a modulation and coding format for a transmission via the satellite to the selected user terminal, the identified modulation and coding format selected from a plurality of modulation and coding formats;

associating the modulation and coding format with the one or more packets addressed to the selected user terminal, the association responsive to the identification of the modulation and coding format;

generating a frame for transmitting the one or more packets to the selected user terminal via the satellite, wherein generating the frame comprises;

generating a frame header identifying a size associated with a payload portion of the frame, identifying the modulation and coding format, and identifying a start of frame location; and

encapsulating the one or more packets addressed to the selected user terminal within the payload portion of the frame; and

transmitting the generated frame, the payload portion transmitted according to the modulation and coding format to the selected user terminal.

2. The method of claim 1, further comprising:

receiving information from the user terminal, the information corresponding to a changed reception quality for the user terminal in e×

cess of a threshold; and

changing the modulation and coding format for other packets destined for the user terminal to account for the changed reception quality.

3. The method of claim 1, wherein the payload portion of the frame is a time-division multiplexed signal.

4. The method of claim 1, wherein the payload portion of the frame comprises internet protocol (IP) packets addressed to the selected user terminal.

5. The method of claim 1, wherein the payload portion of the frame is a variable-length payload portion.

6. The method of claim 1, further comprising:

encapsulating additional packets in the payload portion of the frame addressed to the other user terminals.

7. The method of claim 1, wherein the frame header comprises binary phase shift key symbols.

8. The method of claim 1, wherein the frame header comprises a synchronization slot, a frame definition slot, and a user header slot.

9. The method of claim 1, wherein the frame header comprises a synchronization slot identifying the start of frame location, a frame definition slot identifying the modulation and coding format, and a user header slot identifying the size associated with the payload portion of the frame.

10. The method of claim 1, wherein the frame header comprises a frame definition slot identifying the modulation and coding format for the packet and a user header slot identifying a size associated with the packet, the size associated with the packet comprising the size associated with the payload portion of the frame.

11. The method of claim 1, wherein the frame header comprises a plurality of time slots of the frame before the payload portion of the frame.

12. The method of claim 1, wherein the frame header comprises a first time slot identifying the modulation and coding format and a second time slot identifying the start of frame location, and the first time slot and the second time slot are not immediately adjacent in time.

13. The method of claim 12, wherein the frame header further comprises a third time slot identifying the size associated with the payload portion of the frame, and wherein the third time slot and the second time slot are not immediately adjacent in time and the third time slot and the first time slot are not immediately adjacent in time.

14. The method of claim 1, wherein the frame header comprises a unique word to identify the start of frame location.

15. A gateway for transmitting one or more packets via a satellite to a selected user terminal of a plurality of user terminals, the gateway comprising:

a receiver module configured to receive information corresponding to a reception quality from the satellite for the selected user terminal, the information transmitted from the selected user terminal;

a processor module, communicatively coupled with the receiver module, and configured to;

utilize the received information to identify a modulation and coding format for a transmission via the satellite to the user terminal, the identified modulation and coding format selected from a plurality of modulation and coding formats;

associate the modulation and coding format with the one or more packets addressed to the selected user terminal, the association responsive to the identified modulation and coding format; and

generate a frame for transmitting the one or more packets to the selected user terminal via the satellite, wherein the generation of the frame comprises;

generating a frame header identifying a size associated with a payload portion of the frame, identifying the modulation and coding format, and identifying a start of frame location; and

encapsulating the one or more packets addressed to the selected user terminal within the payload portion of the frame; and

a transmitter module, communicatively coupled with the processor module, and configured to transmit the generated frame, the payload portion transmitted according to the modulation and coding format to the selected user terminal.

16. The gateway of claim 15, wherein

the receiver module is further configured to receive information from the user terminal, the information corresponding to a changed reception quality for the user terminal in excess of a threshold;

and

the processor module is further configured to change the modulation and coding format for other packets destined for the user terminal to account for the changed reception quality.

17. The gateway of claim 15, wherein the payload portion of the frame comprises internet protocol (IP) packets addressed to the selected user terminal and other user terminals, wherein the payload portion is a variable-length payload portion and is time-division multiplexed.

18. A computer readable storage medium configured with instructions executable to:

receive data corresponding to a signal quality for received transmissions from the satellite at the selected user terminal, the signal quality data generated at least in part by the selected user terminal;

utilize the received signal quality data to identify a modulation and coding format for a transmission via the satellite to the user terminal, the identified modulation and coding format selected from a plurality of modulation and coding formats;

associate the modulation and coding format with one or more packets addressed to the selected user terminal, the association responsive to the identified modulation and coding format;

generate a frame for transmitting the one or more packets to the selected user terminal via the satellite, wherein the generation of the frame comprises;

generating a frame header identifying a size associated with a payload portion of the frame, identifying the modulation and coding format, and identifying a start of frame location; and

encapsulating the one or more packets addressed to the selected user terminal within the payload portion of the frame; and

transmit the generated frame to the selected user terminal, the payload portion transmitted according to the modulation and coding format.

19. The computer readable storage medium of claim 18, wherein the instructions are further executable to:

receive data from the user terminal, the information corresponding to a changed reception quality for the user terminal in excess of a threshold; and

change the modulation and coding format for other packets destined for the user terminal to account for the changed reception quality.

20. The computer readable storage medium of claim 18, wherein the payload portion of the frame comprises internet protocol (IP) packets addressed to the selected user terminal and other user terminals, wherein the payload portion is a variable-length payload portion and is time-division multiplexed.

21. A method for transmitting one or more packets via a satellite to a selected user terminal of a plurality of user terminals, the device comprising:

receiving information corresponding to a changed reception quality for the selected user terminal for transmissions received from the satellite, the information generated at least in part by the selected user terminal;

evaluating the information to identify a changed modulation and coding format from a plurality of modulation and coding formats for transmissions to the selected user terminal;

associating the changed modulation and coding format with one or more packets addressed to the selected user terminal, the association corresponding to the identification of the changed modulation and coding format;

generating a frame for transmitting the one or more packets to the selected user terminal via the satellite, wherein generating the frame comprises;

generating a frame header identifying a size associated with a payload portion of the frame, identifying the modulation and coding format, and identifying a start of frame location; and

encapsulating the one or more packets addressed to the selected user terminal within the payload portion of the frame; and

transmitting the one or more packets in the payload portion of the generated frame according to the changed modulation and coding format, the transmission to the selected user terminal via satellite.

22. The method of claim 21, wherein the payload portion of the frame comprises internet protocol (IP) packets addressed to the selected user terminal.

23. The method of claim 21, wherein the payload portion of the frame is a variable-length payload portion.

24. The method of claim 21, further comprising:

encapsulating additional packets in the payload portion of the frame addressed to the other user terminals.

25. The method of claim 21, wherein the frame header comprises a synchronization slot identifying the start of frame location, a frame definition slot identifying the modulation and coding format, and a user header slot identifying the size associated with the payload portion of the frame.

26. The method of claim 21, wherein the frame header comprises a frame definition slot identifying the modulation and coding format for the packet and a user header slot identifying a size associated with the packet, the size associated with the packet comprising the size associated with the payload portion of the frame.

27. The method of claim 21, wherein the frame header comprises a plurality of time slots before the payload portion of the frame.

28. The method of claim 21, wherein the frame header comprises:

a first time slot identifying the modulation and coding format;

a second time slot identifying the start of frame location, wherein the first time slot and the second time slot are not immediately adjacent in time; and

a third time slot identifying the size associated with the payload portion of the frame, and wherein the third time slot and the second time slot are not immediately adjacent in time and the third time slot and the first time slot are not immediately adjacent in time.

29. The method of claim 21, wherein the frame header comprises a unique word to identify the start of frame location.