Systems and methods for reducing satellite feeder link bandwidth/carriers in cellular satellite systems

• US 20030224785A1
• Filed: 12/23/2002
• Published: 12/04/2003
• Est. Priority Date: 05/28/2002
• Status: Active Grant

• Current Assignee: ATC Technology Corporation (FedEx Corporation)
• Original Assignee: ATC Technology Corporation (FedEx Corporation)
• Inventors: Karabinis, Peter D.
• Granted Patent: US 6,937,857 B2
• Time in Patent Office: Days
• US Class Current: 455/428
• CPC Class Codes: H04B 7/18515 Transmission equipment in satellites or space-based relays
• CPC Class Codes: H04B 7/2121 Channels assignment to the different stations
• CPC Class Codes: H04B 7/216 Code division or spread-spectrum multiple access [CDMA, SSMA]

Abstract

Information content is nonidentically mapped between service link carriers and feeder link carriers at a cellular satellite. A reduced number of satellite feeder link carriers compared to the number of satellite service link carriers and/or a reduced total bandwidth of the satellite feeder link carriers compared to the satellite service link carriers thereby may be obtained.

Claims

1. A cellular satellite communications method comprising:

packing at a cellular satellite, information from a plurality of return service link carriers into a return feeder link carrier.

2. A cellular satellite communications method according to claim 1 further comprising:

unpacking at the cellular satellite, information from a forward feeder link carrier into a plurality of forward service link carriers.

3. A cellular satellite communications method according to claim 2:

wherein the packing comprises packing at the cellular satellite, information from the plurality of return service link carriers into fewer return feeder link carriers; and

wherein the unpacking comprises unpacking at the cellular satellite, information from a plurality of forward feeder link carriers into more forward service link carriers.

4. A cellular satellite communications method according to claim 2:

wherein the packing comprises packing at the cellular satellite, information from the plurality of return service link carriers having a total aggregate return service link bandwidth into at least one return feeder link carrier having a total return feeder link bandwidth that is less than the total aggregate return service link bandwidth; and

wherein the unpacking comprises unpacking at the cellular satellite, information from at least one forward feeder link carrier having a total forward feeder link bandwidth into the plurality of forward service link carriers having a total aggregate forward service link bandwidth that is greater than the total forward feeder link bandwidth.

5. A cellular satellite communications method according to claim 2:

wherein the packing comprises packing at the cellular satellite, information from the plurality of return service link carriers to fill the return feeder link carrier; and

wherein the unpacking comprises unpacking at the cellular satellite, information from at least one forward feeder link carrier that is filled, into more forward service link carriers.

6. A cellular satellite communications method according to claim 1:

wherein the packing comprises loading slots in TDMA frames of a return feeder link carrier from TDMA frames of a plurality of return service link carriers that are not fully loaded.

7. A cellular satellite communications method according to claim 6 wherein the loading comprises demodulating the return service link carriers and modulating the return feeder link carriers at the satellite.

8. A cellular satellite communications method according to claim 2:

wherein the packing comprises selectively loading slots in TDMA frames of a return feeder link carrier from TDMA frames of a plurality of return service link carriers that are not fully loaded; and

wherein the unpacking comprises selectively routing slots in TDMA frames of a forward feeder link carrier to TDMA frames of selected ones of the forward service link carriers.

9. A cellular satellite communications method according to claim 8 wherein the unpacking comprises demodulating the forward feeder link carrier and modulating the forward service link carriers at the satellite.

10. A cellular satellite communications method according to claim 2:

wherein the packing comprises selectively loading slots in TDMA frames of a return feeder link carrier from TDMA frames of a plurality of return service link carriers that are not fully loaded; and

wherein the unpacking comprises selectively replicating TDMA frames of a forward feeder link carrier to TDMA frames of selected ones of the forward service link carriers.

11. A cellular satellite communications method according to claim 10 wherein the selectively replicating further comprises:

reducing power in selected ones of the slots of the TDMA frames of the selected ones of the forward service link carriers.

12. A cellular satellite communications method according to claim 1:

wherein the packing comprises combining direct sequence spread return service link carriers that are not fully loaded into one return feeder link carrier.

13. A cellular satellite communications method according to claim 12 wherein the combining comprises demodulating the return service link carriers and modulating the return feeder link carrier at the satellite.

14. A cellular satellite communications method according to claim 2:

wherein the packing comprises combining direct sequence spread information from return service link carriers that are not fully loaded into one return feeder link carrier; and

wherein the unpacking comprises selectively routing direct sequence spread information from a forward feeder link carrier to selected ones of the forward service link carriers.

15. A cellular satellite communications method according to claim 14 wherein the selectively routing comprises demodulating the forward feeder link carriers and modulating the forward service link carriers at the satellite.

16. A cellular satellite communications method according to claim 2:

wherein the packing comprises combining direct sequence spread information from return service link carriers that are not fully loaded into one return feeder link carrier; and

wherein the unpacking comprises selectively replicating direct sequence spread information from a forward feeder link carrier to selected ones of the forward service link carriers.

17. A cellular satellite communications method according to claim 16 wherein the selectively replicating further comprises:

reducing power in selected direct sequence spread information of the selected ones of the forward service link carriers.

18. A cellular satellite communications method comprising:

nonidentically mapping at a cellular satellite, information content between a plurality of service link carriers and a plurality of feeder link carriers.

19. A cellular satellite communications method according to claim 18 wherein the nonidentically mapping comprises routing information from one feeder link carrier into a plurality of service link carriers.

20. A cellular satellite communications method according to claim 18 wherein the nonidentically mapping comprises replicating information from one feeder link carrier into a plurality of service link carriers.

21. A cellular satellite communications method according to claim 18 wherein the nonidentically mapping comprises combining information from a plurality of service link carriers into one feeder link carrier.

22. A cellular satellite communications method according to claim 18 wherein the nonidentically mapping comprises nonidentically mapping at a cellular satellite, information content between a plurality of service link carriers and fewer feeder link carriers.

23. A cellular satellite communications method according to claim 18 wherein the nonidentically mapping comprises nonidentically mapping at a cellular satellite, information content between a plurality of service link carriers having a total aggregate service link bandwidth into at least one feeder link carrier having a total feeder link bandwidth that is less than the total aggregate service link bandwidth.

24. A space segment for a cellular satellite communications system comprising:

a satellite that is configured to receive information from a gateway over a plurality of forward feeder link carriers, to transmit information to the gateway over a plurality of return feeder link carriers, to transmit information to a plurality of satellite cells over a plurality of forward service link carriers and to receive information from the plurality of satellite cells over a plurality of return service link carriers, the satellite being further configured to pack information from the plurality of return service link carriers into the plurality of return feeder link carriers.

25. A space segment according to claim 24 wherein the satellite is further configured to unpack information from the plurality of forward feeder link carriers into the plurality of forward service link carriers.

26. A space segment according to claim 25 wherein the satellite is further configured to pack information from the plurality of return service link carriers into fewer return feeder link carriers, and to unpack information from the plurality of forward feeder link carriers into more forward service link carriers.

27. A space segment according to claim 25 wherein the satellite is further configured to pack information from the plurality of return service link carriers having a total aggregate return service link bandwidth into at least one return feeder link carrier having a total return feeder link bandwidth that is less than the total aggregate return service link bandwidth, and to unpack information from at least one forward feeder link carrier having a total forward feeder link bandwidth into the plurality of forward service link carriers having a total aggregate forward service link bandwidth that is greater than the total forward feeder link bandwidth.

28. A space segment according to claim 25 wherein the satellite is further configured to pack information from the plurality of return service link carriers to fill at least one return feeder link carrier, and to unpack information from at least one forward feeder link carrier that is filled, into more forward service links.

29. A space segment according to claim 24 wherein the satellite is further configured to load slots in TDMA frames of a return feeder link carrier from TDMA frames of a plurality of return service link carriers that are not fully loaded.

30. A space segment according to claim 29 wherein the satellite is further configured to demodulate the return service link carriers and modulate the return feeder link carriers.

31. A space segment according to claim 25 wherein the satellite is further configured to selectively load slots in TDMA frames of a return feeder link carrier from TDMA frames of a plurality of return service link carriers that are not fully loaded, and to selectively route slots in TDMA frames of a forward feeder link carrier to TDMA frames of selected ones of the forward service link carriers.

32. A space segment according to claim 31 wherein the satellite is further configured to demodulate the forward feeder link carrier and modulate the forward service link carriers.

33. A space segment according to claim 25 wherein the satellite is further configured to selectively load slots in TDMA frames of a return feeder link carrier from TDMA frames of a plurality of return service link carriers that are not fully loaded, and to selectively replicate TDMA frames of a forward feeder link carrier to TDMA frames of selected ones of the forward service link carriers.

34. A space segment according to claim 33 wherein the satellite is further configured to reduce power in selected ones of the slots of the TDMA frames of the selected ones of the forward service link carriers.

35. A space segment according to claim 24 wherein the satellite is further configured to combine direct sequence spread return service link carriers that are not fully loaded into one return feeder link carrier.

36. A space segment according to claim 35 wherein the satellite is further configured to demodulate the return service link carriers and modulate the return feeder link carrier.

37. A space segment according to claim 25 wherein the satellite is further configured to combine direct sequence spread information from return service link carriers that are not fully loaded into one return feeder link carrier, and to selectively route direct sequence spread information from a forward feeder link carrier to selected ones of the forward service link carriers.

38. A space segment according to claim 37 wherein the satellite is further configured to demodulate the forward feeder link carriers and modulate the forward service link carriers.

39. A space segment according to claim 25 wherein the satellite is further configured to combine direct sequence spread information from return service link carriers that are not fully loaded into one return feeder link carrier, and selectively replicate direct sequence spread information from a forward feeder link carrier to selected ones of the forward service link carriers.

40. A space segment according to claim 39 wherein the satellite is further configured to reduce power in selected direct sequence spread information of the selected ones of the forward service link carriers.

41. A satellite for a cellular satellite communications system comprising:

first means for receiving first information from a gateway over a first plurality of forward feeder link carriers having a total forward feeder link bandwidth;

first means for transmitting the first information to a plurality of satellite cells over a second plurality of forward service link carriers having a total aggregate forward service link bandwidth, wherein the first plurality is less than the second plurality and/or the total forward feeder link bandwidth is less than the total aggregate forward service link bandwidth;

second means for receiving second information from the plurality of satellite cells over a third plurality of return service link carriers having a total aggregate return service link bandwidth; and

second means for transmitting the second information to the gateway over a fourth plurality of return feeder link carriers having a total return feeder link bandwidth, wherein the fourth plurality is less than the third plurality and/or the total return feeder link bandwidth is less than the total aggregate return service link bandwidth.

42. A satellite according to claim 41 further comprising:

means for unpacking the first information from the first plurality of forward feeder link carriers into the second plurality of forward service link carriers; and

means for packing the second information from the third plurality of return service link carriers into the fourth plurality of return feeder link carriers.

43. A satellite according to claim 41 wherein the means for unpacking comprises means for routing TDMA slots from one of the forward feeder link carriers into a plurality of the forward service link carriers, and wherein the means for packing comprises means for routing TDMA slots from a plurality of the return service link carriers into one of the return feeder link carriers.

44. A satellite according to claim 41 wherein the means for unpacking comprises means for replicating TDMA slots from one of the forward feeder link carriers into a plurality of the forward service link carriers, and wherein the means for packing comprises means for routing TDMA slots from a plurality of the return service link carriers into one of the return feeder link carriers.

45. A satellite according to claim 44 wherein the first means for transmitting comprises means for transmitting the first information in at least some of the slots at reduced power.

46. A satellite according to claim 41 further comprising:

first means for demodulating the first information from the first plurality of forward feeder link carriers;

first means for modulating the first information onto the second plurality of forward service link carriers;

second means for demodulating the second information from the third plurality of return service link carriers; and

fourth means for modulating the third information onto the fourth plurality of return feeder link carriers.

47. A satellite according to claim 41 wherein the means for unpacking comprises means for routing direct sequence spread information from one of the forward feeder link carriers into a plurality of the forward service link carriers, and wherein the means for packing comprises means for routing direct sequence spread information from a plurality of the return service link carriers into one of the return feeder link carriers.

48. A satellite according to claim 41 wherein the means for unpacking comprises means for replicating direct sequence spread information from one for the forward feeder link carriers into a plurality of the forward service link carriers, and wherein the means for packing comprises means for routing direct sequence spread information from a plurality of the return service link carriers into one of the return feeder link carriers.

49. A satellite according to claim 48 wherein the first means for transmitting comprises means for transmitting the direct sequence spread information in at least some of the slots at reduced power.

50. A satellite according to claim 48 in combination with a gateway that is configured to generate the first plurality of forward feeder link carriers and to receive the fourth plurality of return feeder link carriers.

51. A satellite according to claim 48 in combination with a plurality of wireless terminals that are configured to receive the second plurality of forward service link carriers and to generate the third plurality of return service link carriers.

52. A cellular satellite communications method comprising:

receiving first information from a gateway over a first plurality of forward feeder link carriers having a total forward feeder link bandwidth;

transmitting the first information to a plurality of satellite cells over a second plurality of forward service link carriers having a total aggregate forward service link bandwidth, wherein the first plurality is less than the second plurality and/or the total forward feeder link bandwidth is less than the total aggregate forward service link bandwidth;

receiving second information from the plurality of satellite cells over a third plurality of return service link carriers having a total aggregate return service link bandwidth; and

transmitting the second information to the gateway over a fourth plurality of return feeder link carriers having a total return feeder link bandwidth, wherein the fourth plurality is less than the third plurality and/or the total return feeder link bandwidth is less than the total aggregate return service link bandwidth.

53. A method according to claim 52 further comprising:

unpacking the first information from the first plurality of forward feeder link carriers into the second plurality of forward service link carriers; and

packing the second information from the third plurality of return service link carriers into the fourth plurality of return feeder link carriers.

54. A method according to claim 52 wherein unpacking comprises routing TDMA slots from one of the forward feeder link carriers into a plurality of the forward service link carriers, and wherein the packing comprises routing TDMA slots from a plurality of the return service link carriers into one of the return feeder link carriers.

55. A method according to claim 52 wherein the unpacking comprises replicating TDMA slots from one of the forward feeder link carriers into a plurality of the forward service link carriers, and wherein the packing comprises routing TDMA slots from a plurality of the return service link carriers into one of the return feeder link carriers.

56. A method according to claim 55 wherein the transmitting the first information comprises transmitting the first information in at least some of the slots at reduced power.

57. A method according to claim 52 further comprising:

demodulating the first information from the first plurality of forward feeder link carriers;

modulating the first information onto the second plurality of forward service link carriers;

demodulating the second information from the third plurality of return service link carriers; and

modulating the third information onto the fourth plurality of return feeder link carriers.

58. A method according to claim 52 wherein the unpacking comprises routing direct sequence spread information from one of the forward feeder link carriers into a plurality of the forward service link carriers, and wherein the packing comprises routing direct sequence spread information from a plurality of the return service link carriers into one of the return feeder link carriers.

59. A method according to claim 52 wherein the unpacking comprises replicating direct sequence spread information from one for the forward feeder link carriers into a plurality of the forward service link carriers, and wherein the packing comprises routing direct sequence spread information from a plurality of the return service link carriers into one of the return feeder link carriers.

60. A method according to claim 59 wherein the transmitting the first information comprises transmitting the direct sequence spread information in at least some of the slots at reduced power.