ADAPTIVE USE OF SATELLITE UPLINK BANDS

• US 20090290530A1
• Filed: 03/18/2009
• Published: 11/26/2009
• Est. Priority Date: 09/26/2006
• Status: Active Grant

• Current Assignee: ViaSat Incorporated
• Original Assignee: ViaSat Incorporated
• Inventors: Miller, Mark J., Dankberg, Mark D., Wilson, Robert, Jaska, Kristi
• Granted Patent: US 8,315,199 B2
• Time in Patent Office: Days
• US Class Current: 370/316
• CPC Class Codes: H04B 7/18513 Transmission in a satellite or space-based system
• CPC Class Codes: H04B 7/18543 for adaptation of transmission parameters, e.g. power control for detecting or preventing errors in the information received H04L1/00
• CPC Class Codes: H04B 7/18582 Arrangements for data linking, i.e. for data framing, for error recovery, for multiple access

Abstract

A method is presented for transmitting data in a satellite system having multiple spot beams comprising (1) sending a broadband signal in a forward direction from a gateway terminal to a communications satellite for relay to at least one subscriber terminal, (2) receiving the broadband signal at the communications satellite, wherein the communications satellite comprises a bent pipe repeater having a plurality of satellite-based transmission amplifiers, (3) using one of the plurality of satellite-based transmission amplifiers to amplify the broadband signal and no other broadband signal from the gateway terminal, to produce an amplified broadband signal, (4) sending the amplified broadband signal as one of a plurality of service spot beams to the at least one subscriber terminal, and (5) receiving and retrieving data from the amplified broadband signal at the at least one subscriber terminal.

Claims

1. A method for allocating transmission bandwidth in a satellite system, the method comprising:

receiving an assignment of a first transmit frequency channel;

transmitting satellite uplink signals during time-separated periods of transmission in the first assigned transmit frequency channel;

monitoring the first assigned transmit frequency channel between the time-separated periods of transmission of satellite uplink signals;

generating an observation result relating to possible presence of another signal in the first assigned transmit frequency channel;

receiving an indication of a re-assignment to a second assigned transmit frequency channel in response to the observation result; and

transmitting second satellite uplink signals in the second assigned transmit frequency.

2. A method for allocating transmission bandwidth in a satellite system, the method comprising:

assigning a first transmit frequency channel to a user terminal;

at the user terminal, transmitting satellite uplink signals during time-separated periods of transmission in the first assigned transmit frequency channel, monitoring the first assigned transmit frequency channel between the time-separated periods of transmission of satellite uplink signals from the user terminal, generating an observation result relating to possible presence of another signal in the first assigned transmit frequency channel, and reporting the observation result to a remote processor;

at the remote processor, re-assigning the user terminal to a second assigned transmit frequency channel in response to the observation result reported by the user terminal, and causing to be transmitted a message conveying an indication of the second assigned transmit frequency to the user terminal; and

at the user terminal, in response to the message conveying the re-assignment, transmitting second satellite uplink signals in the second assigned transmit frequency.

3. The method of claim 2 further comprising the step of monitoring at least one out-of-band frequency channel different from the first assigned transmit frequency channel to generate the at least one observation result, wherein the at least one observation result further relates to possible presence of a signal in the at least one out-of-band frequency channel.

4. The method of claim 3 wherein the at least one out-of-band frequency channel comprises neighboring frequency channels adjacent to the first assigned transmit frequency channel.

5. The method of claim 2 wherein the at least one observation result indicates presence of an outside source that is a primary spectrum license holder, and the user terminal is a secondary spectrum license holder.

6. The method of claim 2 wherein the at least one observation result indicates presence of a Land Mobile Data Services (LMDS) user.

7. The method of claim 2 wherein the user terminal is further capable of receiving satellite downlink signals in a first assigned receive frequency channel using a first antenna and monitoring the first assigned transmit frequency channel using a second antenna.

8. The method of claim 7 wherein the first antenna is configured for receiving satellite signals, and the second antenna is configured for receiving terrestrial signals.

9. The method of claim 2 wherein the remote processor takes into account observation results reported by other user terminals, in addition to the at least one observation result reported by the user terminal, in determining the re-assignment of the user terminal to the second assigned transmit frequency channel.

10. A bandwidth-allocation system for allocating transmission bandwidth in a satellite system, the bandwidth-allocation comprising:

a user terminal;

a remote processor configured to communicate with the user terminal, the remote processor configured to assign the user terminal to transmit satellite uplink signals in a first assigned transmit frequency channel;

the user terminal configured to transmit the satellite uplink signals during time-separated periods of transmission in the first assigned transmit frequency channel, monitor the first assigned transmit frequency channel between the time-separated periods of transmission of satellite uplink signals from the user terminal, generate an observation result relating to possible presence of another signal in the first assigned transmit frequency channel, and report the observation result to the remote processor;

the remote processor further configured to re-assign the user terminal to a second assigned transmit frequency channel in response to the observation result reported by the user terminal, and cause to be transmitted a message conveying an indication of the second assigned transmit frequency to the user terminal; and

the user terminal further configured to transmit second satellite uplink signals in the second assigned transmit frequency channel in response to the message.

11. The apparatus of claim 10 wherein the user terminal is capable of monitoring at least one out-of-band frequency channel different from the first assigned transmit frequency channel to generate the at least one observation result, wherein the at least one observation result further relates to possible presence of a signal in the at least one out-of-band frequency channel.

12. The apparatus of claim 11 wherein the at least one out-of-band frequency channel comprises neighboring frequency channels adjacent to the first assigned transmit frequency channel.

13. The apparatus of claim 10 wherein the at least one observation result indicates presence of an outside source that is a primary spectrum license holder, and the user terminal is a secondary spectrum license holder.

14. The apparatus of claim 10 wherein the at least one observation result indicates presence of a Land Mobile Data Services (LMDS) user.

15. The apparatus of claim 10 wherein the user terminal is further capable of receiving satellite downlink signals in a first assigned receive frequency channel using a first antenna and monitoring the first assigned transmit frequency channel using a second antenna.

16. The apparatus of claim 15 wherein the first antenna is configured for receiving satellite signals, and the second antenna is configured for receiving terrestrial signals.

17. The apparatus of claim 10 wherein the remote processor is capable of taking into account observation results reported by other user terminals, in addition to the at least one observation result reported by the user terminal, in determining the re-assignment of the user terminal to the second assigned transmit frequency channel.

18. A user terminal for allocating transmission bandwidth in a satellite system, the user terminal comprising:

a receiver configured to receive a signal instructing the user terminal to transmit satellite uplink signals in a first transmit frequency channel;

a transmitter configured to transmit satellite uplink signals during time-separated periods of transmission in the first assigned transmit frequency channel;

a monitor configured to monitor the first assigned transmit frequency channel between the time-separated periods of transmission of satellite uplink signals from the transmitter and to generate an observation result relating to possible presence of another signal in the first assigned transmit frequency channel;

the transmitter further configured to report an indication of the observation result;

the receiver further configured to receive a re-assignment message indicating a re-assignment of the subscriber terminal to a second assigned transmit frequency channel in response to the observation result; and

the transmitter further configured to transmit second satellite uplink signals in a second assigned transmit frequency channel in response to the re-assignment message.

19. A bandwidth-allocation system for allocating satellite system transmission bandwidth, the bandwidth-allocation system comprising:

transmitting means at a user terminal for transmitting desired satellite uplink signals during time-separated periods in a first assigned transmit frequency channel in accordance with a first assignment;

monitoring means at the user terminal for monitoring the first assigned transmit frequency channel between the time-separated periods and for sending an indication of possible presence of a signal other than the desired satellite uplink signals in the first assigned transmit frequency channel; and

assigning means at a remote device for receiving the indication, determining a re-assignment of the user terminal to a second assigned transmit frequency channel in response to the indication, and causing a message indicating the re-assignment to be sent to the user terminal;

the transmitting means further for transmitting further desired satellite uplink signals during time-separated periods in the second assigned transmit frequency channel in response to the message.