Systems and methods for mobile satellite communications

• US 20090022088A1
• Filed: 07/17/2007
• Published: 01/22/2009
• Est. Priority Date: 07/17/2007
• Status: Active Grant

• Current Assignee: Ovzon Sweden AB
• Original Assignee: OverHorizon Cyprus Plc
• Inventors: Lejnell, Kennet, Wahlberg, Per
• Granted Patent: US 8,948,080 B2
• Time in Patent Office: Days
• US Class Current: 370/321
• CPC Class Codes: H04B 7/18532 Arrangements for managing transmission, i.e. for transporting data or a signalling message

Abstract

Systems and methods of satellite communications for moving terminals, including but not limited to on-the-move and mobile terminals (e.g., on-the-pause terminals), are implemented in certain embodiments using smaller antennas (e.g., aperture area with diameter less than 50 cm), open standard waveforms to secure availability from several suppliers, payment for service only when using the terminal, interference avoidance to adjacent satellites, and low cost. Low cost is achieved in part by operating at frequency bands that are currently operated by terrestrial microwave links so that existing low cost microwave components are utilized. The system also includes an interference elimination system that continuously monitors for interference to adjacent satellites from a user terminal'"'"'s uplink signal. If interference is detected, the interference elimination system remedies the interference by performing one or more of the following: shutting down the interfering terminal(s), changing transmission parameters, changing the beam coverage on ground, changing the frequency of the affected traffic, or moving the satellite to a new orbital position. The interference elimination system may also transit the interference information to a control center.

Claims

1. A satellite communications system for moving terminals, including but not limited to on-the-move and mobile user terminals, the system comprising:

a satellite configured to receive an uplink signal from and transmit a downlink signal to moving terminals, the satellite comprising

a regenerative payload,

an onboard computer, and

a payload interface coupled to both the regenerative payload and the onboard computer.

2. The system according to claim 1 further comprising a user terminal comprising an antenna configured to send the uplink signal to the satellite.

3. The system according to claim 2 further comprising a target terminal comprising an antenna configured to receive the downlink signal from the satellite.

4. The system according to claim 1 wherein the system operates on Ku-band frequencies.

5. The system according to claim 4 wherein the Ku-band frequencies are shared by satellite communication and terrestrial microwave links.

6. The system according to claim 4 wherein the Ku-band frequencies are substantially in the range from 12.75 to 13.25 GHz for the uplink signal.

7. The system according to claim 4 wherein the Ku-band frequencies are substantially in the range from 10.7 to 10.95, 11.2 to 11.45 GHz for the downlink signal.

8. The system according to claim 2 wherein the user terminal antenna comprises an aperture area having a diameter less than 50 cm.

9. The system according to claim 3 wherein the target terminal antenna comprises an aperture area having a diameter less than 50 cm.

10. The system according to claim 1 wherein the system is optimized for a link margin of 5 dB or less.

11. The system according to claim 2 wherein microwave components are utilized by the user terminal.

12. The system according to claim 3 wherein microwave components are utilized by the target terminal.

13. The system according to claim 2 wherein the user terminal is configured for mobile communications.

14. The system according to claim 3 wherein the target terminal is configured for mobile communications.

15. The system according to claim 2 wherein the user terminal is configured for on-the-move communications.

16. The system according to claim 3 wherein the target terminal is configured for on-the-move communications.

17. The system according to claim 1 wherein data throughput of the uplink signal and the downlink signal is greater than required to permit voice communications.

18. The system according to claim 1 wherein data throughput of the uplink signal and the downlink signal is between 0.5 to 8.0 Mbps.

19. The system according to claim 1 wherein the satellite occupies one of the groups consisting of (i) a geostationary orbit, and (ii) a geosynchronous orbit.

20. The system according to claim 1 wherein the satellite further comprises steerable transmit and receive spot beams.

21. The system according to claim 1 wherein the satellite further comprises high sensitivity receive beams.

22. The system according to claim 2 wherein the user terminal implements a pay to use billing method.

23. The system according to claim 22 wherein the pay to use billing method is a method implemented by a fixed satellite service.

24. The system according to claim 1 wherein the regenerative payload is configured to use open standard waveforms.

25. The system according to claim 24 wherein the satellite further comprises an onboard mobile phone base station.

26. The system according to claim 25 wherein the onboard mobile phone base station is coupled to the regenerative payload.

27. The system according to claim 1 wherein the regenerative payload comprises a mobile phone base station.

28. The system according to claim 1 wherein the payload interface is coupled to at least one of the group consisting of (i) an interference elimination system, (ii) onboard communication equipment, (iii) sensor systems, and (iv) other satellite equipment.

29. The system according to claim 1 wherein the payload interface is coupled to an interference elimination system configured to detect adjacent satellite interference and generate an interference status.

30. The system according to claim 29 wherein the interference elimination system is configured to transmit the interference status to a satellite control center.

31. The system according to claim 29 wherein the interference elimination system is configured to transmit the interference status to a satellite control center only if the interference status indicates the uplink signal is potentially interfering with adjacent satellites.

32. The system according to claim 29 wherein the interference elimination system performs at least one of the group consisting of (i) shutting down the user terminal, (ii) changing transmission parameters, (iii) changing beam coverage, (iv) changing frequency of affected signal traffic, and (v) moving the satellite to another orbital position, if the interference status indicates the uplink signal is interfering with adjacent satellites.

33. A method of implementing a satellite communications system for moving terminals, including but not limited to on-the-move and mobile terminals, comprising the steps of:

providing a satellite configured to receive an uplink signal from and transmit a downlink signal to moving terminals, the satellite comprising

a regenerative payload,

an onboard computer, and

a payload interface coupled to both the regenerative payload and the onboard computer.

34. The method according to claim 33 further comprising the step of activating a user terminal comprising an antenna configured to send the uplink signal to the satellite.

35. The method according to claim 34 further comprising the step of activating a target terminal comprising an antenna configured to receive the downlink signal from the satellite.

36. The method according to claim 33 wherein the system is configured to operate on Ku-band frequencies.

37. The method according to claim 36 wherein the Ku-band frequencies are substantially in the range from 12.75 to 13.25 GHz for the uplink signal.

38. The system according to claim 36 wherein the Ku-band frequencies are shared by satellite communication and terrestrial microwave links.

39. The method according to claim 36 wherein the Ku-band frequencies are substantially in the range from 10.7 to 10.95, 11.2 to 11.45 GHz for the downlink signal.

40. The method according to claim 34 wherein the user terminal antenna comprises an aperture area having a diameter less than 50 cm.

41. The method according to claim 35 wherein the target terminal antenna comprises an aperture area having a diameter less than 50 cm.

42. The method according to claim 33 further comprising the step of optimizing the system for a link margin of 5 dB or less.

43. The method according to claim 34 wherein microwave components are utilized by the user terminal.

44. The method according to claim 35 wherein microwave components are utilized by the target terminal.

45. The method according to claim 34 further comprising the step of configuring the user terminal for mobile communications.

46. The method according to claim 35 further comprising the step of configuring the target terminal for mobile communications.

47. The method according to claim 34 further comprising the step of configuring the user terminal for on-the-move communications.

48. The method according to claim 35 further comprising the step of configuring the target terminal for on-the-move communications.

49. The method according to claim 33 further comprising the step of configuring data throughput of the uplink signal and the downlink signal to be greater than that required to permit voice communications.

50. The method according to claim 33 further comprising the step of configuring data throughput of the uplink signal and the downlink signal to be between 0.5 to 8.0 Mbps.

51. The method according to claim 33 wherein the satellite further comprises steerable transmit and receive spot beams.

52. The method according to claim 33 wherein the satellite further comprises high sensitivity receive beams.

53. The method according to claim 34 wherein the user terminal implements a pay to use billing method.

54. The method according to claim 53 wherein the pay to use billing method is a method implemented by a fixed satellite service.

55. The method according to claim 33 further comprising the step of configuring the regenerative payload to use open standard waveforms.

56. The method according to claim 55 further comprising installing an onboard mobile phone base station on the satellite.

57. The method according to claim 56 further comprising the step of coupling the onboard mobile phone base station to the regenerative payload.

58. The method according to claim 33 wherein the regenerative payload comprises a mobile phone base station

59. The method according to claim 33 further comprising coupling the payload interface to at least one of the group consisting of (i) an interference elimination system, (ii) onboard communication equipment, (iii) a sensor system, and (iv) other satellite equipment.

60. The method according to claim 33 further comprising coupling the payload interface to an interference elimination system configured to detect adjacent satellite interference and generate an interference status.

61. The method according to claim 60 wherein the interference elimination system is configured to transmit the interference status to a satellite control center.

62. The method according to claim 60 wherein the interference elimination system is configured to transmit the interference status to a satellite control center only if the interference status indicates the uplink signal is potentially interfering with adjacent satellites.

63. The method according to claim 60 further comprising the step of configuring the interference elimination system to perform at least one of the group consisting of (i) shutting down the user terminal, (ii) changing transmission parameters, (iii) changing beam coverage, (iv) changing frequency of affected signal traffic, and (v) moving the satellite to another orbital position, if the interference status indicates the uplink signal is interfering with adjacent satellites.

64. The method according to claim 33 wherein the step of providing a satellite comprises launching the satellite into orbit.

65. The method according to claim 64 wherein the satellite is launched into one of the groups consisting of (i) a geostationary orbit, and (ii) a geosynchronous orbit.

66. A method of operating a satellite communications system for moving terminals, including but not limited to on-the-move and mobile terminals, comprising the steps of:

adjusting the satellite communications system from a first frequency band to a second frequency band that is less populated than the first frequency band;

monitoring for interference towards adjacent satellites from an uplink signal from a user terminal; and

remedying the interference if interference to adjacent satellites from the uplink signal is detected.

67. The method according to claim 66 wherein the monitoring is continuously preformed.

68. The method according to claim 66 wherein the interference is remedied by means of at least one of the group consisting of (i) shutting down the user terminal, (ii) changing transmission parameters, (iii) changing beam coverage, (iv) changing frequency of affected signal traffic, and (v) moving the satellite to another orbital position.

69. The method according to claim 66 further comprising the step of transmitting interference information to a control center.

70. The method according to claim 66 further comprising the step of transmitting interference information to a control center only if interference to adjacent satellites from the uplink signal is at least one of (i) indicated and (ii) detected.

71. A payload interface for use in a satellite, the payload interface comprising:

an input port for connecting to an onboard application of the satellite;

a processor configured to communicate with both the onboard application of the satellite and an onboard payload of the satellite; and

an output port for connecting to the onboard payload of the satellite.

72. The payload interface according to claim 71 wherein the onboard application of the satellite comprises at least one of the group consisting of (i) an interference elimination system, (ii) onboard communication equipment, (iii) a sensor system, and (iv) other satellite equipment.

73. A payload interface for use in a satellite, the payload interface comprising:

an input port for connecting to an onboard application of the satellite;

a first processor configured to communicate with the at least one onboard application of the satellite;

a second processor configured to communicate with an onboard payload of the satellite; and

an output port for connecting to the onboard payload of the satellite.

74. The payload interface according to claim 73 wherein the onboard application of the satellite comprises at least one of the group consisting of (i) an interference elimination system, (ii) onboard communication equipment, (iii) a sensor system, and (iv) other satellite equipment.