Satellite Communications Apparatus and Methods Using Asymmetrical Forward and Return Link Frequency Reuse

• US 20070026867A1
• Filed: 07/20/2006
• Published: 02/01/2007
• Est. Priority Date: 07/29/2005
• Status: Active Grant

• Current Assignee: ATC Technology Corporation (FedEx Corporation)
• Original Assignee: ATC Technology Corporation (FedEx Corporation)
• Inventors: Karabinis, Peter
• Granted Patent: US 7,623,867 B2
• Time in Patent Office: Days
• US Class Current: 455/447
• CPC Class Codes: H04B 7/18539 Arrangements for managing radio, resources, i.e. for establishing or releasing a connection

Abstract

Communications are conducted between a space-based component of the wireless communications system and radioterminals using a plurality of forward link cells and a plurality of return link cells, the return link cells having a greater number of cells per frequency reuse cluster than the forward link cells. At least some of the forward and return link cells may use at least some frequencies of a terrestrial wireless communications system having an adjacent and/or overlapping coverage area. Forward links of the at least some of the forward and return link cells may have a greater link bandwidth than return links of the at least some of the forward and return link cells.

Claims

1. A method of operating a wireless communications system, the method comprising:

communicating between a space-based component of the wireless communications system and radioterminals using a plurality of forward link cells and a plurality of return link cells, the return link cells having a greater number of cells per frequency reuse cluster than the forward link cells.

2. The method of claim 1, wherein forward links of the forward link cells have a greater link bandwidth than return links of the return link cells.

3. The method of claim 2, wherein forward and return links of the forward and return link cells are frequency division duplexed.

4. The method of claim 2, farther comprising orthogonal frequency division multiplexed communications on the forward and/or return links.

5. The method of claim 1, wherein at least some of the forward and return link cells use at least some frequencies of a terrestrial wireless communications system having an adjacent and/or overlapping coverage area.

6. The method of claim 5, where forward links of the at least some of the forward and return link cells have a greater link bandwidth than return links of the at least some of the forward and return link cells.

7. The method of claim 6, wherein service links of the terrestrial wireless communications system using forward link frequencies of the at least some of the forward and return link cells have substantially the same link bandwidth as forward links of the at least some of the forward and return link cells using the forward link frequencies, and wherein service links of the terrestrial wireless communications system using return link frequencies of the at least some of the forward and return link cells have substantially the same link bandwidth as return links of the at least some of the forward and return link cells using the return link frequencies.

8. The method of claim 5, further comprising frequency division duplex communications on forward and return links of the at least some of the forward and return link cells and time division duplex communications on service links of the terrestrial wireless communications system.

9. The method of claim 5, further comprising orthogonal frequency division multiplexed communications on service links of the terrestrial wireless communications system.

10. The method of claim 5, further comprising communicating between the space-based component and radioterminals using a first air interface protocol and communicating between the terrestrial wireless communications system and radioterminals using a second air interface protocol substantially different than the first air interface protocol.

11. The method of claim 5, further comprising communicating between the space-based component and radioterminals and between the terrestrial wireless communications system and radioterminals using substantially the same air interface protocol.

12. The method of claim 5, further comprising communicating between the space-based component and radioterminals using a time division multiplexed (TDM) air interface protocol, a time division multiple access (TDMA) air interface protocol, a code division multiplexed (CDM) air interface protocol, a code division multiple access (CDMA) air interface protocol, an orthogonal frequency division multiplexed (OFDM) air interface protocol, and/or an orthogonal frequency division multiple access (OFDMA) air interface protocol and communicating between the terrestrial wireless communications system using a time division multiplexed (TDM) air interface protocol, a time division multiple access (TDMA) air interface protocol, a code division multiplexed (CDM) air interface protocol, a code division multiple access (CDMA) air interface protocol, an orthogonal frequency division multiplexed (OFDM) air interface protocol, and/or an orthogonal frequency division multiple access (OFDMA) air interface protocol.

13. The method of claim 5, further comprising directing transmissions of radiators of the terrestrial wireless communications system located proximate a boundary of the coverage area of the terrestrial wireless communications system away from a portion of a coverage area of the space-based component outside of the coverage area of the terrestrial wireless communications system.

14. The method of claim 13, wherein directing transmissions of radiators of the terrestrial wireless communications system located proximate a boundary of the coverage area of the terrestrial wireless communications system away from a portion of a coverage area of the space-based component outside of the coverage area of the terrestrial wireless communications system comprises directing transmissions of the radiators of the terrestrial wireless communications system located proximate the boundary of the coverage area of the terrestrial wireless communications system toward an inner portion of the coverage area of the terrestrial wireless communications system.

15. The method of claim 1, wherein multiple ones of the return link cells overlap a single one of the forward link cells.

16. The method of claim 15, wherein the forward link cells have a unity frequency reuse cluster size and wherein the return link cells have a frequency reuse cluster size greater than one.

17. The method of claim 16, wherein respective frequency reuse clusters for the return link cells are substantially spatially coextensive with respective ones of the forward link cells.

18. A wireless communications system comprising:

a space-based component configured to communicate with radioterminals using a plurality of forward link cells and a plurality of return link cells, the return link cells having a greater number of cells per frequency reuse cluster than the forward link cells.

19. The system of claim 18, wherein forward links of the forward link cells have a greater link bandwidth than return links of the return link cells.

20. The system of claim 19, wherein forward and return links of the forward and return link cells are frequency division duplexed.

21. Tie system of claim 19, further comprising orthogonal frequency division multiplexed communications on the forward and/or return links.

22. The system of claim 18, wherein at least some of the forward and return link cells use at least some frequencies of a terrestrial wireless communications system having an adjacent and/or overlapping coverage area.

23. The system of claim 22, wherein forward links of the at least some of forward and return link cells have a greater link bandwidth than return links of the at least some of the forward and return link cells.

24. The system of claim 23, wherein service links of the terrestrial wireless communications system using forward link frequencies of the at least some of the forward and return link cells have substantially the same link bandwidth as forward links of the at least some of the forward and return link cells using the forward link frequencies, and wherein service links of the terrestrial wireless communications system using return link frequencies of the at least some of the forward and return link cells have substantially the same link bandwidth as return links of the at least some of the forward and return link cells using the return link frequencies.

25. The system of claim 22, wherein the space-based component is configured to support frequency division duplexing of communications on forward and return links of the at least some of the forward and return link cells.

26. The system of claim 22, wherein the space-based component is configured to communicate with radioterminals using a first air interface protocol that is substantially different than a second air interface protocol used for communications between the terrestrial wireless communications system and radioterminals.

27. The system of claim 22, wherein the space-based component is configured to communicate with radioterminals using substantially the same air interface protocol used to communicate between the terrestrial wireless communications system and radioterminals.

28. The system of claim 22, wherein the space-based component is configured to communicate with radioterminals using a time division multiplexed (TDM) air interface protocol, a time division multiple access (TDMA) air interface protocol, a code division multiplexed (CDM) air interface protocol, a code division multiple access (CDMA) air interface protocol, an orthogonal frequency division multiplexed (OFDM) air interface protocol, and/or an orthogonal frequency division multiple access (OFDMA) air interface protocol.

29. The system of claim 18, further comprising an ancillary terrestrial component adjacent and/or overlapped at least some of the forward link cells and the return link cells and configured to communicate with radioterminals using at least some frequencies used by the at least some of the forward and return link cells.

30. The system of claim 29, where forward links of the at least some of the forward and return link cells have a greater link bandwidth than return links of the at least some of the forward and return link cells.

31. The system of claim 30, wherein service links of the ancillary terrestrial component using forward link frequencies of the at least some of the forward and return link cells of the space-based component have substantially the same link bandwidth as forward links of the at least some of the forward and return link cells using the forward link frequencies, and wherein service links of the ancillary terrestrial component using return link frequencies of the at least some of the forward and return link cells have substantially the same link bandwidth as return links of the at least some of the forward and return link cells using the return link frequencies.

32. The system of claim 29, wherein the space-based component is configured to support frequency division duplexing of communications on the forward and return links of the at least some of the forward and return link cells and wherein the ancillary terrestrial component is configured to support time division duplexing of communications on the service links of the ancillary terrestrial component.

33. The system of claim 29, wherein the ancillary terrestrial component is configured to support orthogonal frequency division multiplexed communications on service links of the ancillary terrestrial component.

34. The system of claim 29, wherein the space-based component is configured to communicate with radioterminals using a first air interface protocol and wherein the ancillary terrestrial component is configured to communicate with terminals using a second air interface protocol substantially different than the first air interface protocol.

35. The system of claim 29, wherein the space-based component and the ancillary terrestrial component are configured to communicate with radioterminals using substantially the same air interface protocol.

36. The system of claim 29, wherein the space-based component is configured to communicate with radioterminals using a time division multiplexed (TDM) air interface protocol, a time division multiple access (TDNA) air interface protocol, a code division multiplexed (CDM) air interface protocol, a code division multiple access (CDMA) air interface protocol, an orthogonal frequency division multiplexed (OFDM) air interface protocol, and/or an orthogonal frequency division multiple access (OFDMA) air interface protocol and wherein the ancillary terrestrial component is configured to communicate with radioterminals using a time division multiplexed (TDM) air interface protocol, a time division multiple access (TDMA) air interface protocol, a code division multiplexed (CDM) air interface protocol, a code division multiple access (CDMA) air interface protocol, an orthogonal frequency division multiplexed (OFDM) air interface protocol, and/or an orthogonal frequency division multiple access (OFDMA) air interface protocol.

37. The system of claim 29, wherein the ancillary terrestrial component is configured to direct transmissions of radiators thereof located proximate a boundary of the coverage area of the ancillary terrestrial component away from a portion of a coverage area of the space-based component outside of the coverage area of the ancillary terrestrial component.

38. The system of claim 37, wherein the ancillary terrestrial component is configured to direct transmissions of the radiators located proximate the boundary of the coverage area of the ancillary terrestrial component toward an inner portion of the coverage area of the terrestrial wireless communications system.

39. A radioterminal configured to communicate with the system of claim 29.

40. The system of claim 18, wherein multiple ones of the return link cells overlap a single one of the forward link cells.

41. The system of claim 18, wherein the forward link cells have a unity frequency reuse cluster size and wherein the return link cells have a frequency reuse cluster size greater than one.

42. The system of claim 41, wherein respective frequency reuse clusters for the return link cells are substantially spatially coextensive with respective ones of the forward link cells.

43. A radioterminal configured to communicate with the system of claim 18.

44. A terrestrial wireless communications system comprising at least one station configured to communicate with radioterminals in a coverage area adjacent and/or overlapped by forward link cells and return link cells served by a space-based component of a mobile satellite communication system, wherein the return link cells have a greater number of cells per frequency reuse cluster than the forward link cells and the at least one station of the terrestrial wireless communications system is configured to use at least some frequencies used by the forward and return link cells.

45. The terrestrial wireless communications system of claim 44, wherein forward links of forward link cells of the space-based component have a greater link bandwidth than return links of return link cells of the space-based component.

46. The terrestrial wireless communications system of claim 45, wherein service links of the terrestrial wireless communications system using forward link frequencies of the forward link cells of the space-based component have substantially the same link bandwidth as forward links of the forward link cells using the forward link frequencies, and wherein service links of the at least one station of the terrestrial wireless communications system using return link frequencies of the return link cells of the space-based component have substantially the same link bandwidth as return links of the return link cells using the return link frequencies.

47. The terrestrial wireless communications system of claim 44, wherein the at least one station is configured to support time division duplex communications on the service links thereof.

48. The terrestrial wireless communications system of claim 44, wherein the at least one station is configured to support orthogonal frequency division multiplexed communications on service link thereof.

49. The terrestrial wireless communications system of claim 44, wherein the at least one station is configured to communicate with radioterminals using a substantially different air interface protocol than an air interface protocol used by the space-based component in the forward and return link cells.

50. The terrestrial wireless communications system of claim 44, wherein the at least one station is configured to communicate with radioterminals using substantially the same air interface protocol as an air interface protocol used by the space-based component in the forward and return link cells.

51. The terrestrial wireless communications system of claim 44, wherein the at least one station is configured to communicate with radioterminals using a time division multiplexed (TDM) air interface protocol, a time division multiple access (TDMA) air interface protocol, a code division multiplexed (CDM) air interface protocol, a code division multiple access (CDMA) air interface protocol, an orthogonal frequency division multiplexed (OFDM) air interface protocol, and/or an orthogonal frequency division multiple access (OFDMA) air interface protocol.

52. The terrestrial wireless communications system of claim 44, further comprising radiators located proximate a boundary of the coverage area of the terrestrial wireless communications system and configured to direct transmissions thereof away from a portion of a coverage area of the space-based component outside of the coverage area of the terrestrial wireless communications system.

53. The terrestrial wireless communications system of claim 44, further comprising radiators located proximate the boundary of the coverage area of the terrestrial wireless communications system and configured to direct transmissions thereof toward an inner portion of the coverage area of the terrestrial wireless communications system.

54. The terrestrial wireless communications system of claim 44, wherein the at least one station is configured to operate as an ancillary terrestrial component of the mobile satellite communications system.

55. A radioterminal configured to communicate with the terrestrial wireless communications system of claim 44.