System and method for communication utilizing time division duplexing

• US 20070184778A1
• Filed: 02/09/2006
• Published: 08/09/2007
• Est. Priority Date: 02/09/2006
• Status: Active Grant

• Current Assignee: COM Investments LLC (Pendrell Corporation)
• Original Assignee: Eagle River Holdings LLC (Pendrell Corporation)
• Inventors: Mechaley, Robert
• Granted Patent: US 7,769,375 B2
• Time in Patent Office: Days
• US Class Current: 455/12.100
• CPC Class Codes: H04B 7/2125 Synchronisation

Abstract

An integrated communication system includes a satellite portion and a terrestrial portion. A plurality of timeslots are allocated for transmission and reception of data by the various components of the satellite portion and terrestrial portion. The allocation of timeslots to the satellite portion and the terrestrial portion may be predetermined or dynamically allocated based on traffic loads, time of day, day of week, and the like. Communication may be accomplished on a single frequency with the appropriate allocation of timeslots. The system includes delay compensation to accommodate signal processing delays and signal propagation delays. For example, a satellite may be instructed to terminate transmission prior to the end of its allocated timeslot to permit the signal from the satellite to propagate to its intended destination within the allocated timeslot to thereby avoid spillover into the next timeslot. This avoids interference between various elements of the communication system.

Claims

1. A communication system having a satellite network portion and a terrestrial network portion, the system comprising:

a satellite;

a satellite transmitter configured to transmit data on a selected frequency;

a satellite receiver configured to receive data on the selected frequency;

a satellite timing controller to selectively control operation of the satellite transmitter and the satellite receiver;

a first terrestrial station;

a first terrestrial transmitter configured to transmit data on the selected frequency;

a first terrestrial receiver configured to receive data on the selected frequency; and

a first terrestrial timing controller configured to selectively control operation of the first terrestrial transmitter and the first terrestrial receiver, wherein the satellite timing controller and the first terrestrial timing controller are configured to cooperatively control the respective transmitters and receivers to control transmission and reception of data in selected time intervals such that the satellite transmitter is enabled to transmit data in a first selected time interval, the satellite receiver receives data in a second selected time interval, the first terrestrial transmitter is enabled to transmit data in a third selected time interval, and the first terrestrial receiver receives data in a fourth selected time interval.

2. The system of claim 1 wherein the first, second, third, and fourth selected time intervals are sequential time intervals.

3. The system of claim 1, further comprising a first user terminal capable of communication with the first terrestrial station only and having a transmitter configured to transmit data on the selected frequency, a receiver configured to receive data on the selected frequency, and a first user terminal timing controller, the first user terminal timing controller being configured to enable the first user terminal receiver to receive data from the first terrestrial station during the third selected time interval and to enable the first user terminal transmitter to transmit data to the first terrestrial station during the fourth selected time interval.

4. The system of claim 3, further comprising a second user terminal capable of communication with the satellite only and having a transmitter configured to transmit data on the selected frequency, a receiver configured to receive data on the selected frequency, and a timing controller, the second user terminal timing controller being configured to enable the second user terminal receiver to receive data from the satellite during the first selected time interval and to enable the second user terminal transmitter to transmit data to the satellite during the second selected time interval.

5. The system of claim 1, further comprising a dual-mode user terminal capable of communication with the first terrestrial station or the satellite and having a transmitter configured to transmit data on the selected frequency, a receiver configured to receive data on the selected frequency, and a timing controller, the dual-mode user terminal timing controller being configured to enable the dual-mode user terminal receiver to receive data from the satellite during the first selected time interval, to enable the dual-mode user terminal transmitter to transmit data to the satellite during the second selected time interval, to enable the dual-mode user terminal receiver to receive data from the first terrestrial station during the third selected time interval and to enable the dual-mode user terminal transmitter to transmit data to the first terrestrial station during the fourth selected time interval.

6. The system of claim 1, further comprising:

a second terrestrial station having a transmitter configured to transmit data on the selected frequency, a receiver configured to receive data on the selected frequency, and a timing controller;

a first user terminal having a transmitter configured to transmit data on the selected frequency, a receiver configured to receive data on the selected frequency, and a timing controller; and

a second user terminal having a transmitter configured to transmit data on the selected frequency, a receiver configured to receive data on the selected frequency, and a timing controller, the first user terminal timing controller being configured to enable the first user terminal receiver to receive data from the first terrestrial station during the third selected time interval and to enable the first user terminal transmitter to transmit data to the first terrestrial station during the fourth selected time interval and the second user terminal timing controller being configured to enable the second user terminal receiver to receive data from the second terrestrial station during a fifth selected time interval and to enable the second user terminal transmitter to transmit data to the second terrestrial station during a sixth selected time interval.

7. The system of claim 1, further comprising a controller configured to allocate the selected time intervals to the satellite and the terrestrial station.

8. The system of claim 7 wherein the controller is configured to allocate a plurality of selected time intervals to a selected one of the satellite and the terrestrial station based on a quantity of data to be transmitted.

9. The system of claim 7 wherein the controller is configured to allocate a plurality of selected time intervals to a selected one of the satellite and the terrestrial station based on a predetermined transmission schedule.

10. The system of claim 7 wherein the controller is configured to allocate a majority of selected time intervals to the satellite.

11. The system of claim 7 wherein the controller is configured to allocate a majority of selected time intervals to the terrestrial station.

12. The system of claim 1 wherein the satellite is configured to communicate with a plurality of coverage areas on the surface of the earth and the first terrestrial station is within a first of the plurality of coverage areas, the system further comprising a second terrestrial station within a second of the plurality of coverage areas adjacent to the first of the plurality of coverage areas.

13. The system of claim 12 wherein communications in the first of the plurality of coverage areas and the second of the plurality of coverage areas both use the selected frequency.

14. The system of claim 12 wherein communications in the first of the plurality of coverage areas uses a first selected frequency and communications in the second of the plurality of coverage areas uses a second selected frequency different from the first selected frequency.

15. The system of claim 12, further comprising a third terrestrial station within a third of the plurality of coverage areas, the second of the plurality of coverage areas being intermediate the first of the plurality of coverage areas and the third of the plurality of coverage areas wherein communications in the first of the plurality of coverage areas uses a first selected frequency, communications in the second of the plurality of coverage areas uses a second selected frequency different from the first selected frequency, and communications in the third of the plurality of coverage areas reuses the first selected frequency.

16. The system of claim 1 wherein the satellite timing controller is configured to terminate transmission from the satellite transmitter prior to the end of the first selected time interval by an amount of time at least equal to a propagation delay between the satellite and the first terrestrial station.

17. The system of claim 1 wherein the satellite timing controller is configured to initiate transmission from the satellite transmitter prior to the start of the first selected time interval by an amount of time substantially equal to a propagation delay between the satellite and the first terrestrial station.

18. The system of claim 1 wherein the first terrestrial timing controller is configured to terminate transmission from the first terrestrial station transmitter prior to the end of the third selected time interval by an amount of time at least equal to a propagation delay between the first terrestrial station and the satellite.

19. The system of claim 1 wherein the first terrestrial timing controller is configured to initiate transmission from the first terrestrial station transmitter prior to the start of the third selected time interval by an amount of time substantially equal to a propagation delay between the first terrestrial station and the satellite.

20. A communication system having a satellite network portion and a terrestrial network portion, the system comprising:

a satellite having a transmitter and receiver configured to communicate on a selected frequency;

a first terrestrial station having a transmitter and receiver configured to communicate on the selected frequency;

a satellite controller to selectively control operation of the satellite transmitter, the satellite controller enabling transmission during a first selected time interval and terminating transmission at a point in time prior to the end of the first selected time interval wherein the point in time prior to the end of the selected time interval is based on a propagation delay between the satellite and the first terrestrial station; and

a first terrestrial controller to selectively control operation of the first terrestrial station transmitter, the first terrestrial controller enabling transmission during a second selected time interval and terminating transmission at a point in time prior to the end of the second selected time interval wherein the point in time prior to the end of the selected time interval is based on a propagation delay between the first terrestrial station and the satellite.

21. The system of claim 20 wherein the first terrestrial station is a mobile user terminal having a transmitter and receiver configured to communicate on the selected frequency.

22. The system of claim 21 wherein the user terminal is configured for communication with the satellite only.

23. The system of claim 21 wherein the user terminal is configured for communication with the satellite or with a second terrestrial station.

24. The system of claim 21, further comprising a system controller configured to determine a propagation delay between the satellite and the first terrestrial station.

25. The system of claim 24 wherein the propagation delay between the satellite and the first terrestrial station is used by the satellite controller to terminate transmission at the point in time prior to the end of the selected time interval.

26. A communication system having a satellite network portion and a terrestrial network portion, the system comprising:

a satellite having a transmitter and receiver configured to transmit and receive data on a selected frequency;

satellite control means for selectively controlling operation of the satellite transmitter and the satellite receiver;

a first terrestrial station having a transmitter and receiver configured to transmit and receive data on the selected frequency;

first terrestrial control means for selectively controlling operation of the first terrestrial transmitter and the first terrestrial receiver, wherein the satellite control means and the first terrestrial control means cooperatively control the respective transmitters and receivers to control transmission and reception of data in selected time intervals such that the satellite transmitter is enabled to transmit data in a first selected time interval, the satellite receiver receives data in a second selected time interval, the first terrestrial transmitter is enabled to transmit data in a third selected time interval, and the first terrestrial receiver receives data in a fourth selected time interval.

27. The system of claim 26, further comprising a first user terminal capable of communication with the first terrestrial station only and having a transmitter configured to transmit data on the selected frequency, a receiver configured to receive data on the selected frequency, and user terminal control means for enabling the first user terminal receiver to receive data from the first terrestrial station during the third selected time interval and for enabling the first user terminal transmitter to transmit data to the first terrestrial station during the fourth selected time interval.

28. The system of claim 27, further comprising a second user terminal capable of communication with the satellite only and having a transmitter configured to transmit data on the selected frequency, a receiver configured to receive data on the selected frequency, and second user terminal control means for enabling the second user terminal receiver to receive data from the satellite during the first selected time interval and for enabling the second user terminal transmitter to transmit data to the satellite during the second selected time interval.

29. The system of claim 26, further comprising a dual-mode user terminal capable of communication with the first terrestrial station or the satellite and having a transmitter configured to transmit data on the selected frequency, a receiver configured to receive data on the selected frequency, and dual-mode user terminal control means for enabling the dual-mode user terminal receiver to receive data from the satellite during the first selected time interval, for enabling the dual-mode user terminal transmitter to transmit data to the satellite during the second selected time interval, for enabling the dual-mode user terminal receiver to receive data from the first terrestrial station during the third selected time interval and for enabling the dual-mode user terminal transmitter to transmit data to the first terrestrial station during the fourth selected time interval.

30. The system of claim 26, further comprising:

a second terrestrial station having a transmitter configured to transmit data on the selected frequency, a receiver configured to receive data on the selected frequency, and second terrestrial station control means for controlling the second terrestrial station transmitter and receiver;

a first user terminal having a transmitter configured to transmit data on the selected frequency, a receiver configured to receive data on the selected frequency, and first user terminal control means for enabling the first user terminal receiver to receive data from the first terrestrial station during the third selected time interval and for enabling the first user terminal transmitter to transmit data to the first terrestrial station during the fourth selected time interval; and

a second user terminal having a transmitter configured to transmit data on the selected frequency, a receiver configured to receive data on the selected frequency, and second user terminal control means for enabling the second user terminal receiver to receive data from the second terrestrial station during a fifth selected time interval and for enabling the second user terminal transmitter to transmit data to the second terrestrial station during a sixth selected time interval.

31. The system of claim 26, further comprising allocation control means for allocating the selected time intervals to the satellite and the terrestrial station.

32. The system of claim 31 wherein the allocation control means allocates a plurality of selected time intervals to a selected one of the satellite and the terrestrial station based on a quantity of data to be transmitted.

33. The system of claim 31 wherein the allocation control means allocates a plurality of selected time intervals to a selected one of the satellite and the terrestrial station based on a predetermined transmission schedule.

34. The system of claim 31 wherein the allocation control means allocates a majority of selected time intervals to the satellite.

35. The system of claim 31 wherein the allocation control means allocates a majority of selected time intervals to the terrestrial station.

36. The system of claim 26 wherein the satellite is configured to communicate with a plurality of coverage areas on the surface of the earth and the first terrestrial station is within a first of the plurality of coverage areas, the system further comprising a second terrestrial station within a second of the plurality of coverage areas adjacent to the first of the plurality of coverage areas.

37. The system of claim 36 wherein communications in the first of the plurality of coverage areas and the second of the plurality of coverage areas both use the selected frequency.

38. The system of claim 36 wherein communications in the first of the plurality of coverage areas uses a first selected frequency and communications in the second of the plurality of coverage areas uses a second selected frequency different from the first selected frequency.

39. The system of claim 36, further comprising a third terrestrial station within a third of the plurality of coverage areas, the second of the plurality of coverage areas being intermediate the first of the plurality of coverage areas and the third of the plurality of coverage areas wherein communications in the first of the plurality of coverage areas uses a first selected frequency, communications in the second of the plurality of coverage areas uses a second selected frequency different from the first selected frequency, and communications in the third of the plurality of coverage areas reuses the first selected frequency.

40. The system of claim 26 wherein the satellite control means comprises means for terminating transmission from the satellite transmitter prior to the end of the first selected time interval by an amount of time at least equal to a propagation delay between the satellite and the first terrestrial station.

41. The system of claim 26 wherein the satellite control means comprises means for initiating transmission from the satellite transmitter prior to the start of the first selected time interval by an amount of time substantially equal to a propagation delay between the satellite and the first terrestrial station.

42. The system of claim 26 wherein the first terrestrial control means comprises means for terminating transmission from the first terrestrial station transmitter prior to the end of the third selected time interval by an amount of time at least equal to a propagation delay between the first terrestrial station and the satellite.

43. The system of claim 26 wherein the first terrestrial control means comprises means for initiating transmission from the first terrestrial station transmitter prior to the start of the third selected time interval by an amount of time substantially equal to a propagation delay between the first terrestrial station and the satellite.

44. A timing correction method for use in an integrated terrestrial and satellite communication system comprising:

allocating a plurality of time slots for use by the communication system, the allocated time slots being used by an earth station for transmission of data and by a satellite for the transmission of data; and

controlling transmission between the earth station and the satellite to compensate for a propagation delay time between the satellite and the earth station to thereby synchronize use of the allocated time slots by both the earth station and the satellite.

45. The method of claim 44 wherein each allocated time slot has a start time and an end time and controlling transmission between the earth station and the satellite comprises terminating transmission from the satellite prior to the end time of a time slot allocated for transmission of data by the satellite.

46. The method of claim 45 wherein controlling transmission between the earth station and the satellite comprises terminating transmission from the satellite prior to the end time by an amount of time substantially equal to the propagation delay time.

47. The method of claim 44 wherein each allocated time slot has a start time and an end time and controlling transmission between the earth station and the satellite comprises initiating transmission from the satellite prior to the start time of a time slot allocated for transmission of data by the satellite.

48. The method of claim 47 wherein controlling transmission between the earth station and the satellite comprises initiating transmission from the satellite prior to the start time by an amount of time substantially equal to the propagation delay time.

49. The method of claim 44 wherein each allocated time slot has a start time and an end time and wherein the earth station transmits data directly to a terrestrial receiver in an allocated time slot, the earth station terminating transmission at a time substantially equal to the end time of the allocated time slot.

50. The method of claim 49 wherein the earth station transmits data to the terrestrial receiver via the satellite with the satellite relaying the data to the terrestrial receiver in an allocated time slot, the satellite terminating transmission at a time prior to the end time of the allocated time slot.

51. The method of claim 44 wherein each allocated time slot has a start time and an end time and wherein a terrestrial transceiver transmits data directly to the earth station in an allocated time slot, the terrestrial receiver terminating transmission at a time substantially equal to the end time of the allocated time slot.

52. The method of claim 51 wherein the terrestrial transceiver transmits data to the earth station via the satellite with the satellite relaying the data to the earth station in an allocated time slot, the satellite terminating transmission at a time prior to the end time of the allocated time slot.

53. The method of claim 44 wherein each allocated time slot has a start time and an end time and controlling transmission between the earth station and the satellite comprises terminating transmission from the earth station prior to the end time of a time slot allocated for transmission of data by the earth station.

54. The method of claim 53 wherein controlling transmission between the earth station and the satellite comprises terminating transmission from the earth station prior to the end time by an amount of time substantially equal to the propagation delay time.

55. The method of claim 44 wherein each allocated time slot has a start time and an end time and controlling transmission between the earth station and the satellite comprises initiating transmission from the earth station prior to the start time of a time slot allocated for transmission of data by the earth station.

56. The method of claim 55 wherein controlling transmission between the earth station and the satellite comprises initiating transmission from the earth station prior to the start time by an amount of time substantially equal to the propagation delay time.

57. The method of claim 44 wherein allocating a plurality of time slots for use by the communication system comprises allocating a first portion of the time slots for transmission of data by the earth station and allocating a second portion of the time slots for transmission of data by the satellite.

58. The method of claim 44 wherein allocating a plurality of time slots for use by the communication system comprises allocating a first portion of the time slots for reception of data by the earth station and allocating a second portion of the time slots for reception of data by the satellite.

59. The method of claim 44 wherein allocating a plurality of time slots for use by the communication system comprises allocating a first portion of the time slots for transmission of data by the earth station, allocating a second portion of the time slots for transmission of data by the satellite, allocating a third portion of the time slots for reception of data by the earth station, and allocating a fourth portion of the time slots for reception of data by the satellite.

60. The method of claim 59 wherein the allocation of the first, second, third and fourth portions of the plurality of time slots is based on a quantity of communication traffic by at least one terrestrial transmitter.

61. The method of claim 59 wherein the allocation of the first, second, third and fourth portions of the plurality of time slots is based on a quantity of communication traffic by a plurality of terrestrial transmitters.

62. The method of claim 59 wherein the allocation of the first, second, third and fourth portions of the plurality of time slots is based a time of day, a day of the week or both.

63. The method of claim 59 wherein the allocation of the first, second, third and fourth portions of the plurality of time slots is based a coverage area of the earth station, a coverage area of the satellite, or both.

64. The method of claim 44 wherein the transmission of data by the earth station utilizes a selected frequency channel and the transmission of data by the satellite utilizes the selected frequency channel.