Satellite system with steerable gateway beams

• US 10,418,724 B2
• Filed: 06/03/2016
• Issued: 09/17/2019
• Est. Priority Date: 03/29/2016
• Status: Active Grant

• Current Assignee: Maxar Space LLC (Galileo Parent, Inc.)
• Original Assignee: Space Systems/Loral Incorporated (Loral Space and Communications Incorporated)
• Inventors: Hreha, William, Wharton, Anne Elizabeth
• Primary Examiner(s): Heiber, Shantell L
• Application Number:
  US15/172,978
• Publication Number:
  US 20180006711A1
• Time in Patent Office: 1,201 Days
• CPC Class Codes: H01Q 21/24 Combinations of antenna units polarised in different directions for transmitting or receiving circularly and elliptically polarised waves or waves linearly polarised in any direction circularly polarised patch antennas H01Q9/0428; circularly polarised horns H01Q13/0241; cross-polarised horns H01Q13/0258; polarisation converters H01Q15/242; cross-polarised rear feeds H01Q19/136; crossed polarisation dual antenna H01Q25/001
• CPC Class Codes: H01Q 3/2682 Time delay steered arrays
• CPC Class Codes: H04B 7/043 using best eigenmode, e.g. beam forming or beam steering
• CPC Class Codes: H04B 7/18513 Transmission in a satellite or space-based system
• CPC Class Codes: H04B 7/18515 Transmission equipment in satellites or space-based relays
• CPC Class Codes: H04B 7/18519 Operations control, administration or maintenance
• CPC Class Codes: H04B 7/18521 Systems of inter linked satellites, i.e. inter satellite service for optical links between satellites H04B10/118
• CPC Class Codes: H04B 7/18523 Satellite systems for providing broadcast service to terrestrial stations, i.e. broadcast satellite service arrangements specially adapted for satellite broadcast receiving H04H40/90; picture transmission via satellite H04N1/00103; television transmission via satellite H04N7/20
• CPC Class Codes: H04B 7/18534 for enhancing link reliablility, e.g. satellites diversity
• CPC Class Codes: H04B 7/18541 for handover of resources
• CPC Class Codes: H04B 7/18547 for geolocalisation of a station position fixing by direction or distance determination G01S5/00
• 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 7/18584 Arrangements for data networking, i.e. for data packet routing, for congestion control data switching networks H04L12/00
• CPC Class Codes: H04B 7/18595 Arrangements for adapting broadband applications to satellite systems
• CPC Class Codes: H04B 7/19 Earth-synchronous stations
• CPC Class Codes: H04W 16/28 using beam steering
• CPC Class Codes: H04W 56/0015 one node acting as a reference for the others
• CPC Class Codes: H04W 72/0446 Resources in time domain, e.g. slots or frames
• CPC Class Codes: H04W 72/0453 Resources in frequency domain, e.g. a carrier in FDMA
• CPC Class Codes: H04W 72/046 the resource being in the space domain, e.g. beams
• CPC Class Codes: H04W 72/21 : in the uplink direction of a wireless link, i.e. towards the network
• CPC Class Codes: H04W 72/23 : in the downlink direction of a wireless link, i.e. towards a terminal
• CPC Class Codes: H04W 84/18 : Self-organising networks, e.g. ad-hoc networks or sensor networks

Abstract

A satellite communication system includes a non-geostationary satellite configured to provide a first plurality of non-articulated spot beams that comprise a Field of Regard. The satellite further configured to provide a steerable spot beam that can be steered to establish communication with a gateway outside and in front of the Field of Regard and maintain communication while the satellite and the Field of Regard moves over and past the gateway including after the gateway is outside of and behind the Field of Regard.

Claims

1. A satellite communication system, comprising:

a non-geostationary satellite configured to provide a first plurality of spot beams that comprise a Field of Regard that is a current area on Earth that the satellite can communicate with based on current position such that as the satellite travels along an orbital path the Field of Regard moves over the Earth'"'"'s surface, the satellite further configured to provide a steerable spot beam that can communicate with a gateway where the gateway is capable of communicating with a subscriber terminal via the steerable spot beam when the subscriber terminal is within the Field of Regard, the satellite is configured to point the steerable spot beam at the gateway and communicate with the gateway prior to the subscriber terminal and the gateway being within the Field of Regard, the satellite configured to provide communication between the gateway and the subscriber terminal while the Field of Regard moves over the subscriber terminal and the subscriber terminal communicates with the gateway via the satellite using different spot beams of the first plurality of spot beams, the satellite is configured to communicate with the gateway subsequent to the subscriber terminal and the gateway being within the Field of Regard.

2. The satellite communication system of claim 1, wherein:

the first plurality of spot beams are fixed in position with respect to the satellite.

3. The satellite communication system of claim 2, wherein:

the first plurality of spot beams form a hopping group, all of the spot beams of the hopping group utilize a same frequency and polarization, the satellite configured to perform time domain beam hopping such that the spot beams of the hopping group use a same shared frequency bandwidth at different times with the shared frequency bandwidth hoping between spot beams such that only a subset of the sport beams in the hopping group are active at a time.

4. The satellite communication system of claim 3, wherein:

the satellite configured to communicate between the satellite and the subscriber terminal via the steerable spot beam and turn off a spot beam of the hoping group that overlaps with the steerable spot beam during the time domain beam hopping.

5. The satellite communication system of claim 1, wherein:

the first plurality of spot beams includes a Field of View that the satellite is communicating with at an instance in time, the Field if View is smaller than the Field of Regard.

6. The satellite communication system of claim 1, wherein:

the satellite is configured to establish internal connectivity in the satellite to service the gateway, including providing at least an initial bandwidth for the gateway.

7. The satellite communication system of claim 6, wherein:

the satellite is configured to provision more bandwidth for the gateway as more subscriber terminals establish communication with the gateway via the satellite due to movement of the satellite; and

the satellite is configured to provision less bandwidth to the gateway as more subscriber terminals stop communication with the gateway via the second satellite.

8. The satellite communication system of claim 1, wherein:

the satellite configured to receive handover of more terminals from an adjacent satellite by establishing communication between the more terminals and the gateway as the Field of Regard of the satellite traverses across a region supported by the gateway and providing more bandwidth to the gateway beam.

9. The satellite communication system of claim 1, wherein:

the satellite is configured to lose terminals to a handover to another satellite as the Field of Regard of the satellite traverses across a region supported by the gateway.

10. The satellite communication system of claim 1, wherein:

the satellite is configured to break communication with the gateway when the satellite is an orbital position in which it can no longer service any terminals supported by the gateway and slew the gateway beam ahead of the satellite to accommodate the next handover.

11. A method of operating a satellite communication system, comprising:

a gateway communicating with terminals via a first satellite while the gateway and the terminals are outside of a Field of Regard of non-articulated beams of a second satellite, the Field of Regard of the non-articulated beams of the second satellite is a current area on Earth that the second satellite can communicate with based on current position of the second satellite such that as the second satellite travels along an orbital path the Field of Regard moves over the Earth'"'"'s surface;

pointing a steerable spot beam of the second satellite to illuminate the gateway while the gateway and the terminals are outside of the Field of Regard of the non-articulated beams of the second satellite;

while the Field of Regard of the non-articulated beams of the second satellite traverses across a region supported by the gateway, preforming handover of the terminals from the first satellite to the second satellite and establishing communication between the terminals and the gateway via the second satellite;

as the Field of Regard for the non-articulated beams of the second Satellite leaves the region supported by the gateway, performing handover of the terminals from the second satellite to a third Satellite for communication with the gateway via the third satellite; and

breaking communication between gateway and the second satellite when the second satellite is at an orbital position in which the gateway is outside of and behind the Field of Regard of the non-articulated beams of the second satellite.

12. The method of claim 11, further comprising:

establishing synchronization between the gateway and the second satellite using a timing beacon while the gateway is communicating with terminals via the first satellite and the gateway is outside of the Field of Regard of non-articulated beams of the second satellite.

13. The method of claim 11, wherein:

the first plurality of spot beams includes a Field of View that the satellite is communicating with at an instance in time, the Field if View is smaller than the Field of Regard.

14. The method of claim 11, further comprising:

breaking communication between gateway and the first satellite when the first satellite is in an orbital position in which it cannot service any terminals supported by the gateway, thereby freeing up a steerable beam of the first satellite to connect to another gateway.

15. The method of claim 11, further comprising:

as more terminals establish communication with the gateway due to movement of the second satellite, provisioning more bandwidth for the gateway via the second satellite; and

as more terminals stop communication with the gateway via the second satellite, provisioning less bandwidth to the gateway for the second satellite.

16. The method of claim 11, further comprising:

maintaining communication between the gateway and the second satellite as long as the second satellite is in orbital position to service any terminals supported by the gateway, even if a Field of Regard for non-articulated spot beams of the second satellite does not illuminate the gateway.

17. The method of claim 11, wherein:

the non-articulated beams of the second satellite form a hopping group, all of the spot beams of the hopping group utilize a same frequency and polarization, the second satellite configured to perform time domain beam hopping such that the spot beams of the hopping group use a same shared frequency bandwidth at different times with the shared frequency bandwidth hoping between spot beams such that only a subset of the sport beams in the hopping group are active at a time.

18. The method of claim 17, wherein:

the second satellite configured to communicate between the second satellite and the terminals via the steerable spot beam of the second satellite and turn off a spot beam of the hoping group that overlaps with the steerable spot beam of the second satellite during the time domain beam hopping.

19. A satellite communication system, comprising:

a first non-geostationary satellite configured to provide a first plurality of spot beams that are fixed in position with respect to the first non-geostationary satellite and comprise a first Field of Regard, the first non-geostationary satellite is configured to provide a first steerable spot beam;

a second non-geostationary satellite configured to provide a second plurality of spot beams that are fixed in position with respect to the second non-geostationary satellite and comprise a second Field of Regard, the second non-geostationary satellite is configured to provide a second steerable spot beam, a set of the second plurality of spot beams form a hopping group, all of the spot beams of the hopping group utilize a same frequency and polarization, the second non-geostationary satellite configured to perform time domain beam hopping such that the spot beams of the hopping group use a same shared frequency bandwidth at different times with the shared frequency bandwidth hoping between spot beams such that only a subset of the sport beams in the hopping group are active at a time;

a third non-geostationary satellite configured to provide a third plurality of spot beams that are fixed in position with respect to the third non-geostationary satellite and comprise a third Field of Regard, the third non-geostationary satellite is configured to provide a third steerable spot beam;

a plurality of terminals; and

a gateway, while the gateway is communicating with the terminals via the first steerable spot beam of the first non-geostationary satellite and the gateway is outside of the second Field of Regard, the second non-geostationary satellite is configured to move the second steerable spot beam to point at the gateway, as the second Field of Regard of the second satellite traverses across a region supported by the gateway the terminals are configured to handover to the second satellite and establish communication with the gateway via the second steerable spot beam, as the second Field of Regard leaves the region supported by the gateway the terminals handover to the third satellite for communication with the gateway via a third steerable spot beam, communication between gateway and the second satellite is stopped when the second non-geostationary satellite is an orbital position in which the gateway is outside of and behind the second Field of Regard, the second non-geostationary satellite is configured to communicate between the satellite and the terminals via the second steerable spot beam and turn off a spot beam of the hoping group that overlaps with the second steerable spot beam during the time domain beam hopping.

20. The satellite communication system according to claim 19, wherein:

the second plurality of spot beams includes a Field of View that the second non-geostationary satellite is communicating with at an instance in time, the Field if View is smaller than the Field of Regard.

21. The satellite communication system according to claim 19, wherein:

the first non-geostationary satellite, the second non-geostationary satellite and the third non-geostationary satellite configured to travel on a same orbital path.