FLEXIBLE CAPACITY SATELLITE CONSTELLATION

• US 20180227043A1
• Filed: 07/26/2016
• Published: 08/09/2018
• Est. Priority Date: 07/31/2015
• Status: Active Grant

• Current Assignee: ViaSat Incorporated
• Original Assignee: ViaSat Incorporated
• Inventors: DANKBERG, MARK D
• Granted Patent: US 10,707,952 B2
• Time in Patent Office: Days
• CPC Class Codes: H01Q 1/288 Satellite antennas
• 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 7/2041 Spot beam multiple access
• CPC Class Codes: H04B 7/2046 SS-TDMA, TDMA satellite switching

Abstract

Embodiments provide in-flight configuration of satellite pathways to flexibly service terra-link and cross-link traffic in a constellation of non-processed satellites, for example, to facilitate flexible forward-channel and return-channel capacity in a satellite communications system. For example, each satellite in the constellation can include one or more dynamically configurable pathway, and switching and/or beamforming can be used to configure each pathway to be a forward-channel pathway or a return-channel pathway in each of a number of timeslots according to a pathway configuration schedule. At least some of the pathways can be further selectively configured, in each timeslot, to carry “terra-link” traffic to and/or from terrestrial terminals and “cross-link” traffic to and/or from one or more other satellites of the constellation.

Claims

1. A satellite system for use in a multi-satellite constellation for providing a communications network, the satellite comprising:

an antenna system comprising a plurality of spot beams, including first and second terra-link beams and a cross-link beam;

a bent-pipe pathway associated with the plurality of spot beams;

a memory coupled with the pathway and having a pathway configuration schedule stored thereon; and

a pathway configuration system to sequentially configure the pathway in each of a plurality of timeslots to form a signal path between a selected pair of the spot beams according to the pathway configuration schedule,

such that the pathway is configured in a first timeslot to establish connectivity between the first and second terra-link beams, and the pathway is configured in a second timeslot to establish connectivity between the first terra-link beam and the cross-link beam.

2. The system of claim 1, wherein the pathway is one of a plurality of pathways, each assigned to a respective subset of the plurality of spot beams, and each sequentially configurable in each timeslot to form a signal path between a selected pair of the respective subset of spot beams according to the pathway configuration schedule.

3. The system of claim 1, wherein the satellite is a low Earth orbit satellite.

4. The system of claim 1, wherein the satellite is a medium Earth orbit satellite.

16. The system of claim 1, wherein the pathway configuration system sequentially configures the pathway in each of the plurality of timeslots to form a physical circuit that couples the selected pair of spot beams according to the pathway configuration schedule.

17. The system of claim 1, wherein:

the pathway has a receive side coupled with a receiver; and

the pathway has a transmit side coupled with a transmitter.

18. The system of claim 1, wherein the antenna system comprises a plurality of fixed feed horns that service the terra-link beams and the cross-link beam.

19. The system of claim 1, wherein the pathway configuration system comprises a receive switch to selectively couple a receive side of the pathway to one of a plurality of receive feeds of the antenna system in each of the plurality of timeslots, according to the pathway configuration schedule, to establish connectivity between the receive feed and a transmit feed coupled with a transmit side of the pathway, thereby sequentially configuring the pathway in each of the plurality of timeslots to form the signal path between the selected pair of spot beams according to the pathway configuration schedule.

20. The system of claim 1, wherein the pathway configuration system comprises a transmit switch to selectively couple a transmit side of the pathway to one of a plurality of transmit feeds of the antenna system in each of the plurality of timeslots, according to the pathway configuration schedule, to establish connectivity between the transmit feed and a receive feed coupled with a receive side of the pathway, thereby sequentially configuring the pathway in each of the plurality of timeslots to form the signal path between the selected pair of spot beams according to the pathway configuration schedule.

21. The system of claim 1, wherein the pathway configuration system comprises:

a receive switch to selectively couple a receive side of the pathway to one of a plurality of receive feeds of the antenna system in each of the plurality of timeslots according to the pathway configuration schedule; and

a transmit switch to selectively couple a transmit side of the pathway to one of a plurality of transmit feeds of the antenna system in each of the plurality of timeslots according to the pathway configuration schedule,

thereby establishing connectivity in each timeslot between a receive spot beam and a transmit spot beam according to the pathway configuration schedule via the receive feed, the pathway, and the transmit feed.

22. The system of claim 1, wherein the antenna system comprises a phased-array antenna that services the terra-link beams and the cross-link beam.

23. The system of claim 22, wherein the pathway configuration system comprises a receive beamforming network coupled between the phased array antenna and a receive side of the pathway, the receive beamforming network operable to adjust beam weightings to form a signal coupling, in each of the plurality of timeslots, between a receive beam and the receive side of the pathway, thereby sequentially configuring the pathway in each of the plurality of timeslots to form the signal path between the selected pair of spot beams according to the pathway configuration schedule, one of the selected pair of spot beams being the receive beam.

24. The system of claim 22, wherein the pathway configuration system comprises a transmit beamforming network coupled between the phased array antenna and a transmit side of the pathway, the transmit beamforming network operable to adjust beam weightings to form a signal coupling, in each of the plurality of timeslots, between a transmit beam and the transmit side of the pathway, thereby sequentially configuring the pathway in each of the plurality of timeslots to form the signal path between the selected pair of spot beams according to the pathway configuration schedule, one of the selected pair of spot beams being the transmit beam.

25. The system of claim 22, wherein the pathway configuration system comprises:

a receive beamforming network coupled between the phased array antenna and a receive side of the pathway, the receive beamforming network operable to adjust beam weightings to form a signal coupling, in each of the plurality of timeslots, between a receive beam and the receive side of the pathway; and

a transmit beamforming network coupled between the phased array antenna and a transmit side of the pathway, the transmit beamforming network operable to adjust beam weightings to form a signal coupling, in each of the plurality of timeslots, between a transmit beam and the transmit side of the pathway,

thereby sequentially configuring the pathway in each of the plurality of timeslots to form the signal path between the selected pair of spot beams according to the pathway configuration schedule, the selected pair of spot beams comprising the receive beam and the transmit beam.

26. The system of claim 25, wherein:

the receive beamforming network is coupled between a first reflector of the phased array antenna and the receive side of the pathway; and

the transmit beamforming network is coupled between a second reflector of the phased array antenna and the transmit side of the pathway.

27. The system of claim 1, wherein the antenna system comprises a plurality of fixed feed horns that service the terra-link beams, and a phased-array antenna that services the cross-link beam.

28. The system of claim 1, wherein the pathway configuration schedule accounts for time-varying interconnectivity between the satellites of the constellation.

29. The system of claim 1, wherein the pathway configuration schedule sequentially configures the pathway according to frames, each frame comprising the plurality of timeslots, a first fraction of the timeslots in each frame supporting forward traffic, and a second fraction of the timeslots in each frame supporting return traffic, the first and second fractions selected according to a computed desired ratio between forward and return capacity.

30. The system of claim 29, wherein some of the first and second fractions of the timeslots in each frame support terra-link traffic, and others of the first and second fractions of the timeslots in each frame support cross-link traffic.

31. The system of claim 1, wherein:

one of the terra-link beams is to communicate uplink traffic in an uplink band and an uplink polarization; and

the other of the terra-link beams is to communicate downlink traffic in a downlink band and a downlink polarization,

wherein the uplink band is different from the downlink band and/or the uplink polarization is different from the downlink polarization.

32. The system of claim 31, wherein:

the cross-link beam is to communicate cross-link traffic in a cross-link band that is different from at least one of the uplink band or the downlink band.

5-15. -15. (canceled)

33. A method for scheduled connectivity switching in a satellite of a multi-satellite constellation, the method comprising:

first configuring a pathway of the satellite to form a bent-pipe signal path that establishes connectivity between a first terra-link beam and a second terra-link beam in a first timeslot according to a pathway configuration schedule stored in memory of the satellite, the satellite having an antenna comprising a plurality of spot beams including the first and second terra-link beams and a cross-link beam; and

second configuring the pathway to form a bent-pipe signal path that establishes connectivity between the first terra-link beam and the cross-link beam in a second timeslot according to the pathway configuration schedule.

34. The method of claim 33, further comprising:

receiving the pathway configuration schedule by the satellite from one of the terrestrial terminals while the satellite is in flight.

35. The method of claim 33, further comprising:

first receiving, subsequent to the first configuring, first traffic as a first uplink communication from a first terrestrial terminal illuminated by the first terra-link beam;

first transmitting, via the pathway, the first traffic as a downlink communication to a second terrestrial terminal illuminated by the second terra-link beam;

second receiving, subsequent to the second configuring, second traffic as a second uplink communication from the first terrestrial terminal illuminated by the first terra-link beam; and

second transmitting, via the pathway, the second traffic as a cross-link communication to another satellite of the constellation illuminated by the cross-link beam.

36. The method of claim 33, wherein the first configuring comprises forming a physical circuit that establishes connectivity between the first terra-link beam and the second terra-link beam according to the pathway configuration schedule.

40. The method of claim 33, wherein configuring the pathway comprises switching a receive switch to selectively couple a receive side of the pathway to one of a plurality of antenna receive feeds in at least one of the plurality of timeslots according to the pathway configuration schedule.

41. The method of claim 33, wherein configuring the pathway comprises switching a transmit switch to selectively couple a transmit side of the pathway to one of a plurality of antenna receive feeds in at least one of the plurality of timeslots according to the pathway configuration schedule.

42. The method of claim 33, wherein configuring the pathway comprises adjusting beam weightings in a receive beamforming network coupled between a phased array antenna and a receive side of the pathway in at least one of the plurality of timeslots according to the pathway configuration schedule.

43. The method of claim 33, wherein configuring the pathway comprises adjusting beam weightings in a transmit beamforming network coupled between a phased array antenna and a transmit side of the pathway in at least one of the plurality of timeslots according to the pathway configuration schedule.

44. The method of claim 33, wherein the pathway configuration schedule accounts for time-varying interconnectivity between the satellites of the constellation.

37-39. -39. (canceled)