Method and system for providing satellite communications

• US 20020077099A1
• Filed: 12/18/2000
• Published: 06/20/2002
• Est. Priority Date: 12/18/2000
• Status: Abandoned Application

• Current Assignee: Space Systems/Loral Incorporated (Loral Space and Communications Incorporated)
• Original Assignee: Space Systems/Loral Incorporated (Loral Space and Communications Incorporated)
• Inventors: LaPrade, James Nicholas
• Application Number:
  US09/739,942
• Publication Number:
  US 20020077099A1
• Time in Patent Office: Days
• US Class Current: 455/430
• CPC Class Codes: H04B 7/18578 Satellite systems for providing broadband data service to individual earth stations for selecting H04W; provisions for broadband connection, H04Q11/0478
• CPC Class Codes: H04B 7/19 Earth-synchronous stations
• CPC Class Codes: H04B 7/195 Non-synchronous stations

Abstract

A broad-band digital satellite communications system for providing broad-band data services. The system comprises a first spacecraft, generally a geo-stationary earth orbit communications device, and at least one controller having broadband communications capability with the first spacecraft. The system also includes at least one second spacecraft, generally a low earth orbit (LEO) communications device. The second spacecraft comprises ; communications capability with the at least one first spacecraft; low data rate communications capability with a land based system, generally a mobile communications service provider; and broadband communications capability with a mobile user subscriber to the mobile communications service provider.

Claims

1. A broad-band digital satellite communications system for providing data services , the system comprising:

at least one first spacecraft;

at least one controller having broadband communications capability with the at least one first spacecraft;

at least one second spacecraft having a lower earth orbit than the at least one first spacecraft, the at least one second spacecraft comprising;

communications capability with the at least one first spacecraft;

low data rate communications capability with at least one first land based system; and

broadband communications capability with at least one second land based system.

2. A broad-band digital satellite communications system as in claim 1 wherein the at least one first spacecraft comprises at least one high earth orbit satellite.

3. A broad-band digital satellite communications system as in claim 2 wherein the at least one high earth orbit satellite comprises at least one geo-stationary earth orbit satellite.

4. A broad-band digital satellite communications system as in claim 1 wherein the at least one second spacecraft comprises at least one low earth orbit satellite.

5. A broad-band digital satellite communications system as in claim 1 wherein the at least one second spacecraft further comprises at least one independent communications beam-former.

6. A broad-band digital satellite communications system as in claim 5 wherein the at least one independent communications beam-former comprises at least one communications data channel.

7. A broad-band digital satellite communications system as in claim 1 wherein the at least one second spacecraft further comprises low data rate time division multiple access (TDMA) communications capability with the at least one first land based system.

8. A broad-band digital satellite communications system as in claim 1 wherein the at least one second spacecraft further comprises low data rate code division multiple access (CDMA) communications capability with the at least one first land based system.

9. A broad-band digital satellite communications system as in claim 1 wherein the at least one second spacecraft further comprises code division multiple access (CDMA) broadband communications capability with the at least one second land based system.

10. A broad-band digital satellite communications system as in claim 1 wherein the at least one second spacecraft further comprises time division multiple access (TDMA) broadband communications capability with the at least one second land based system.

11. A broad-band digital satellite communications system as in claim 1 wherein the broad-band satellite communications system further comprises encryption/decryption capability.

13. A method as in claim 12 wherein the step of transmitting data from at least one geo-stationary earth orbit (GEO) satellite further comprises the steps of:

receiving broadband data on at least one second base station;

transmitting the broadband data on at least one up-link channel from the at least one second base station;

receiving the broadband data transmitted on the at least one up-link channel at the GEO satellite; and

combining the broadband data received on the at least one up-link channel to form a replica of broadband data received at the ground station.

14. A method as in claim 13 wherein the step of receiving broadband data at the at least one second base station further comprises the steps of:

determining if the received broadband data exceeds up-link communication channel capacity; and

adding up-link communication channels based on the determination the received broadband data exceeds up-link communication channel capacity.

15. A method as in claim 12 wherein the step of transmitting the data to the mobile user further comprises the steps of:

determining if the data exceeds available down-link communications channel capacity associated with the at least one down-link communication channel;

increasing the number of available down-link communication channels based on the determination that the data exceeds available down-link communication channel capacity;

parsing the data on to the number of available down-link communication channels; and

transmitting the data on the number of available down-link communication channels to the at least one mobile user.

16. A method as in claim 15 wherein the step of increasing the number of available down-link communication channels based on the determination that the data exceeds available down-link communication channel capacity further comprises the steps of:

determining the number of available independent spot beams;

determining the number of available communication channels for each available independent spot beam;

calculating total down-link communication channel capacity available based on the determination of the number of available communication channels;

determining a total down-link communication channel capacity required to transmit the replicated broadband data;

comparing the total down-link communication channel capacity available with the total down-link communication channel capacity required to transmit the replicated broadband data; and

increasing the number of available independent spot beams if the comparison of the total down-link communication channel capacity available with the total down-link communication channel capacity required to transmit the replicated broadband data indicates more communication channel capacity is required.

17. A method as in claim 16 wherein the step of increasing the number of available independent spot beams further comprises the step of assigning additional independent spot beams from additional satellites within the LEO constellation.

18. A method as in claim 15 wherein the step of transmitting the data on the number of available down-link communication channels to the at least one mobile user further comprises the steps of:

determining a geographical position of the mobile user;

identifying the controllable spot beams associated with the down-link communication channels required to transmit the data to the geographical position of the mobile user;

steering the identified controllable spot beams to illuminate the geographical position of the mobile user; and

transmitting the data on the identified down-link communication channels.

19. A method as in claim 18 wherein the step of steering the identified controllable spot beams to illuminate the position of the mobile user further comprises the step of steering the identified controllable spot beams emanating from a plurality of LEO satellites.

20. A method as in claim 12 wherein the step of determining the geographical position of the mobile user further comprises the steps of:

exchanging low data rate communications between the LEO satellite and at least one mobile base station; and

determining from the exchanged low data rate communications the geographical position of the at least one mobile user.

21. A method as in claim 20 wherein the step of exchanging low data rate communications with the at least one mobile base station further comprises the step of exchanging low data rate communications with a land-based mobile base station.

22. A method as in claim 12 wherein the step of determining the geographical position of the mobile user further comprises the steps of:

transmitting the mobile user'"'"'s global positioning satellite (GPS) coordinates to at least one second base station; and

determining the mobile users position from the GPS coordinates.

24. A broad-band digital satellite communications system as in claim 23 wherein the at least one DTG (DTG) further comprises at least one communications channel with the GEO satellite.

25. A broad-band digital satellite communications system as in claim 23 wherein the at least one LEO broadband communications capability further comprises at least one controllable communications beam-former, each communications beam-former having at least one communications channel.

27. A method as in claim 26 wherein the step of allocating the total up-link resources available from the network controller to up-link data to the at least one first satellite constellation further comprises the steps of:

determining if the data exceeds up-link communication channel capacity;

allocating up-link communication channels based on the determination the data exceeds up-link communication channel capacity;

assigning a unique fraction of the data to each allocated up-link communication channel; and

parallel transmitting the unique fractions of data on each allocated up-link channel from the network controller to the at least one first satellite constellation.

28. A method as in claim 26 wherein the step of broadcasting substantially simultaneously the up-linked data from the at least one first satellite constellation to the at least one second satellite constellation further comprises the step of broadcasting substantially simultaneously the up-linked data from at least one geo-stationary earth orbit (GEO) satellite to at least one low earth orbit (LEO) satellite constellation.

29. A method as in claim 26 wherein the step of assigning spot communication beams associated with the at least one second satellite constellation to transmit a predetermined fraction of the up-linked data further comprises the steps of:

determining a geographical position of a mobile user;

identifying the spot communication beams, associated with the second satellite constellation, required to transmit the data to the geographical position of the mobile user;

steering the identified spot communication beams to illuminate the geographical position of the mobile user; and

transmitting the data on down-link communication channels associated with the identified spot communication beams.

30. A method as in claim 29 wherein the step of determining the geographical position of the mobile user further comprises the steps of:

exchanging low data rate communications between the at least one second satellite constellation and at least one mobile base station; and

determining from the exchanged low data rate communications the geographical position of the at least one mobile user.

31. A method as in claim 29 wherein the step of determining the geographical position of the mobile user further comprises the steps of:

transmitting the mobile user'"'"'s global positioning satellite (GPS) coordinates to the at least one network controller; and

determining the mobile users position from the GPS coordinates.

32. A method as in claim 29 wherein the step of determining the geographical position of the mobile user further comprises the steps of:

transmitting the mobile user'"'"'s latitude/longitude (lat/long) coordinates to the at least one network controller; and

determining the mobile users position from the lat/long coordinates.

12. A method for providing asymmetric broadband data services to a mobile user, the method comprising the steps of:

transmitting data from at least one geo-stationary earth orbit (GEO) satellite, the step of transmitting data from the GEO satellite comprises the steps of;

transmitting data from the GEO satellite to at least one low earth orbit (LEO) satellite constellation, the LEO satellite constellation comprising a plurality of LEO satellites;

determining the geographical position of the mobile user; and

transmitting the data to the mobile user.

23. A broad-band digital satellite communications system for providing asymmetric broad-band data services to a mobile user, the system comprising:

at least one geo-synchronous earth orbit (GEO) satellite;

at least one data traffic gateway (DTG) having broad-band communications capability with the at least one GEO satellite;

at least one controller connectable to the at least one DTG;

at least one low earth orbit (LEO) satellite, the at least one LEO satellite comprising;

communications capability with the at least one DTG;

communications capability with the at least one GEO satellite;

low data rate communications capability with at least one land based system; and

broad-band communications capability the mobile user.

26. A method for maximizing spectral efficiency in a satellite communications system having at least one first satellite constellation disposed at a orbit higher than at least one second satellite constellation, and at least one network controller having communications capability with the at least one first satellite constellation, the method comprising the steps of:

allocating the total up-link resources available from the network controller to up-link data to the at least one first satellite constellation;

broadcasting substantially simultaneously the up-linked data from the at least one first satellite constellation to the at least one second satellite constellation; and

assigning spot communication beams associated with the at least one second satellite constellation to transmit a predetermined fraction of the up-linked data.

33. A communications system for providing internet data services between a user and an internet, the system comprising:

at least one satellite constellation;

at least one first ground station having communications capability with the at least one satellite constellation and the user; and

at least one second ground station having communications capability with the at least one satellite constellation and the internet.

34. A communications system as in claim 33 wherein the communications system further comprises a digital communications system.

35. A communications system as in claim 33 wherein the at least one satellite constellation further comprises a plurality of multi-orbit satellites.

36. A communications system as in claim 33 wherein the at least on satellite constellation further comprises at least one satellite.

37. A communications system as in claim 36 wherein the at least one satellite further comprises at least one steerable spot beam.

38. A communications system as in claim 37 wherein the at least one steerable spot beam further comprises at least one communications channel.

39. A communications system as in claim 33 wherein the at least one first ground station having communications capability with the at least one satellite constellation and the user further comprises the first ground station having multiple communications channels with the at least one satellite constellation.

40. A communications system as in claim 33 wherein the at least one second ground station having communications capability with the at least one satellite constellation further comprises the second ground station having multiple communications channels with the at least one satellite constellation.

41. A method for providing internet data services between at least one first user and an internet, the method comprising the steps:

transmitting data from the at least one first user to a satellite constellation;

assigning the data to at least one communications channel within the satellite constellation;

steering at least one satellite spot communication beam associated with the at least one communications channel to illuminate the internet; and

parallel transmitting data to the internet.

42. A method as in claim 41 wherein the step of transmitting data from the at least one first user to a satellite constellation further comprises the steps of:

transmitting the data to a first ground station;

determining if the data exceeds the ground station'"'"'s up-link communication channel capacity;

allocating up-link communication channels based on the determination the data exceeds up-link communication channel capacity until up-link channel capacity meets or exceeds the amount of data to be transmitted;

assigning a unique fraction of the data to each allocated up-link communication channel; and

parallel transmitting the unique fractions of data on each allocated up-link channel from the first ground station to the satellite constellation.

43. A method as in claim 41 wherein the step of assigning the data to at least one communications channel within the satellite constellation further comprises the step of identifying the at least one satellite spot communication beam, associated with the second satellite constellation, required to illuminate the internet.

44. A method as in claim 43 wherein the step identifying the at least one satellite spot communication beam required to illuminate the internet further comprises the steps of:

determining a geographical position of the internet;

identifying the at least one satellite spot communication beam, associated with the second satellite constellation, required to transmit the data to the geographical position of the internet;

steering the identified at least one satellite spot communication beam to illuminate the geographical position of internet; and

parallel transmitting the data on down-link communication channels associated with the identified at least one satellite spot communication beam.