METHOD AND APPARATUS FOR MULTIPLEXING HYBRID SATELLITE CONSTELLATIONS

• US 20180376392A1
• Filed: 06/19/2018
• Published: 12/27/2018
• Est. Priority Date: 06/21/2017
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Wu, Qiang, Black, Peter John, Liu, Ruoheng
• Granted Patent: US 10,667,188 B2
• Time in Patent Office: Days
• CPC Class Codes: H03M 13/152 Bose-Chaudhuri-Hocquenghem [BCH] codes
• CPC Class Codes: H03M 13/2966 Turbo codes concatenated with another code, e.g. an outer block code
• CPC Class Codes: H04B 7/18504 Aircraft used as relay or high altitude atmospheric platform
• 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 7/19 Earth-synchronous stations
• CPC Class Codes: H04B 7/195 Non-synchronous stations
• CPC Class Codes: H04B 7/2041 Spot beam multiple access
• CPC Class Codes: H04J 3/00 Time-division multiplex systems H04J14/00 takes precedence; relay systems H04B7/14; selecting techniques H04Q
• CPC Class Codes: H04L 1/0057 Block codes H04L1/0061, H04L1/0064 take precedence
• CPC Class Codes: H04L 5/1469 using time-sharing
• CPC Class Codes: H04L 5/26 combined with the use of different frequencies
• CPC Class Codes: H04W 36/0055 Transmission or use of information for re-establishing the radio link
• CPC Class Codes: H04W 36/0072 of resource information of target access point
• CPC Class Codes: H04W 36/08 Reselecting an access point
• CPC Class Codes: H04W 36/165 for reducing network power consumption H04W36/18 - H04W36/22 take precedence
• CPC Class Codes: H04W 36/18 for allowing seamless reselection, e.g. soft reselection
• CPC Class Codes: H04W 36/36 by user or terminal equipment
• CPC Class Codes: H04W 72/0446 Resources in time domain, e.g. slots or frames
• CPC Class Codes: H04W 84/06 Airborne or Satellite Networks space-based or airborne stations H04B7/185

Abstract

A method and apparatus for operating a satellite system including different satellites that may belong to different types of satellite constellations. In some implementations, the satellite system may include a LEO satellite constellation and one or more non-LEO satellite constellations that can be used to increase the forward link capacity of the LEO satellite constellation, for example, by allowing an LEO satellite to offload at least some of its forward link traffic to one of the non-LEO satellites. The user terminals can dynamically switch forward link communications between a LEO satellite and a non-LEO satellite while maintaining a return link connection with the LEO satellite.

Claims

1. A method for switching forward link communications of a user terminal between first and second satellites, the method comprising:

transmitting first data to the user terminal on a forward link of the first satellite;

transmitting time-division multiplexing (TDM) configuration information to the user terminal on the forward link of the first satellite, the TDM configuration information specifying a TDM transmission pattern for forward link communications to the user terminal from at least the first and second satellites;

switching forward link communications of the user terminal from the first satellite to the second satellite during a handover operation;

transmitting second data to the user terminal on a forward link of the second satellite after the handover operation; and

receiving one or more control or data messages from the user terminal on a return link of the first satellite after the handover operation.

2. The method of claim 1, wherein the one or more control or data messages comprise an acknowledgement of the second data received by the user terminal.

3. The method of claim 1, wherein the first satellite comprises a low-earth orbit (LEO) satellite, the second satellite is one of a medium-earth orbit (MEO) satellite or a geosynchronous orbit (GSO) satellite, and the one or more control or data messages comprise information pertaining to the handover operation from the first satellite to the second satellite.

4. The method of claim 1, wherein the first satellite comprises a low-earth orbit (LEO) satellite, the second satellite is one of a medium-earth orbit (MEO) satellite or a geosynchronous orbit (GSO) satellite, and the second satellite does not provide a return link for the user terminal.

5. The method of claim 1, wherein the specified TDM transmission pattern configures the user terminal to exchange data with the first satellite using a first communication frame and to receive data from the second satellite using a second communication frame.

6. The method of claim 1, wherein the specified TDM transmission pattern is based on one or more of latency requirements of data transmitted to the user terminal, a type or classification of data transmitted to the user terminal, and propagation delays of the first and second satellites.

7. The method of claim 1, wherein the specified TDM transmission pattern configures the user terminal to receive forward link communications from a low-earth orbit (LEO) satellite during a first portion of a TDM transmission period, to receive forward link communications from a medium-earth orbit (MEO) satellite during a second portion of a TDM transmission period, and to receive forward link communications from a geosynchronous orbit (GSO) satellite during a third portion of a TDM transmission period.

8. The method of claim 1, wherein the second data is transmitted from the second satellite using a concatenated code including a turbo code as an inner code and including a Bose-Chaudhuri-Hocquenghem (BCH) code as an outer code.

9. The method of claim 1, wherein the handover operation is triggered by a radio controller circuit (RRC) message transmitted to the user terminal using the forward link of the first satellite.

10. The method of claim 9, wherein the first satellite comprises a first low-earth orbit (LEO) satellite, the second satellite is one of a medium-earth orbit (MEO) satellite or a geosynchronous orbit (GSO) satellite, and the RRC message triggers a handover operation between the first satellite and a second LEO satellite.

11. The method of claim 1, further comprising:

maintaining the return link between the first satellite and the user terminal before and after the handover operation.

12. A controller configured to switch forward link communications of a user terminal between first and second satellites, the controller comprising:

one or more processors; and

a memory storing instructions that, when executed by the one or more processors, cause the controller to;

transmit first data to the user terminal on a forward link of the first satellite;

transmit time-division multiplexing (TDM) configuration information to the user terminal on the forward link of the first satellite, the TDM configuration information specifying a TDM transmission pattern for forward link communications to the user terminal from at least the first and second satellites;

switch forward link communications of the user terminal from the first satellite to the second satellite during a handover operation;

transmit second data to the user terminal on a forward link of the second satellite; and

receive one or more control or data messages from the user terminal on a return link of the first satellite after the handover operation.

13. The controller of claim 12, wherein the one or more control or data messages comprise an acknowledgement of the second data received by the user terminal.

14. The controller of claim 12, wherein the first satellite comprises a low-earth orbit (LEO) satellite, the second satellite is one of a medium-earth orbit (MEO) satellite or a geosynchronous orbit (GSO) satellite, and the one or more control or data messages comprise information pertaining to the handover operation from the first satellite to the second satellite.

15. The controller of claim 12, wherein the first satellite comprises a low-earth orbit (LEO) satellite, the second satellite is one of a medium-earth orbit (MEO) satellite or a geosynchronous orbit (GSO) satellite, and the second satellite does not provide a return link for the user terminal.

16. The controller of claim 12, wherein the specified TDM transmission pattern configures the user terminal to exchange data with the first satellite using a first communication frame and to receive data from the second satellite using a second communication frame.

17. The controller of claim 12, wherein the specified TDM transmission pattern is based on one or more of latency requirements of data transmitted to the user terminal, a type or classification of data transmitted to the user terminal, and propagation delays of the first and second satellites.

18. The controller of claim 12, wherein the specified TDM transmission pattern configures the user terminal to receive forward link communications from a low-earth orbit (LEO) satellite during a first portion of a TDM transmission period, to receive forward link communications from a medium-earth orbit (MEO) satellite during a second portion of a TDM transmission period, and to receive forward link communications from a geosynchronous orbit (GSO) satellite during a third portion of a TDM transmission period.

19. The controller of claim 12, wherein the second data is transmitted from the second satellite using a concatenated code including a turbo code as an inner code and including a Bose-Chaudhuri-Hocquenghem (BCH) code as an outer code.

20. The controller of claim 12, wherein the handover operation is triggered by a radio controller circuit (RRC) message transmitted to the user terminal using the forward link of the first satellite.

21. The controller of claim 12, wherein the first satellite comprises a first low-earth orbit (LEO) satellite, the second satellite is one of a medium-earth orbit (MEO) satellite or a geosynchronous orbit (GSO) satellite, and the RRC message triggers a handover operation between the first satellite and a second LEO satellite.

22. The controller of claim 12, wherein execution of the instructions further causes the controller to:

maintain the return link between the first satellite and the user terminal before and after the handover operation.

23. A non-transitory computer-readable medium comprising instructions that, when executed by one or more processors of a controller, cause the controller to switch forward link communications of a user terminal between first and second satellites by performing operations including:

transmitting first data to the user terminal on a forward link of the first satellite;

transmitting time-division multiplexing (TDM) configuration information to the user terminal on the forward link of the first satellite, the TDM configuration information specifying a TDM transmission pattern for forward link communications to the user terminal from at least the first and second satellites;

switching forward link communications of the user terminal from the first satellite to the second satellite during a handover operation;

transmitting second data to the user terminal on a forward link of the second satellite after the handover operation; and

receiving one or more control or data messages from the user terminal on a return link of the first satellite after the handover operation.

24. The non-transitory computer-readable medium of claim 23, wherein the specified TDM transmission pattern configures the user terminal to exchange data with the first satellite using a first communication frame and to receive data from the second satellite using a second communication frame.

25. The non-transitory computer-readable medium of claim 23, wherein the specified TDM transmission pattern is based on one or more of latency requirements of data transmitted to the user terminal, a type or classification of data transmitted to the user terminal, and propagation delays of the first and second satellites.

26. The non-transitory computer-readable medium of claim 23, wherein the specified TDM transmission pattern configures the user terminal to receive forward link communications from a low-earth orbit (LEO) satellite during a first portion of a TDM transmission period, to receive forward link communications from a medium-earth orbit (MEO) satellite during a second portion of a TDM transmission period, and to receive forward link communications from a geosynchronous orbit (GSO) satellite during a third portion of a TDM transmission period.

27. The non-transitory computer-readable medium of claim 23, wherein the handover operation is triggered by a radio controller circuit (RRC) message transmitted to the user terminal using the forward link of the first satellite.

28. The non-transitory computer-readable medium of claim 27, wherein the first satellite comprises a first low-earth orbit (LEO) satellite, the second satellite is one of a medium-earth orbit (MEO) satellite or a geosynchronous orbit (GSO) satellite, and the RRC message triggers a handover operation between the first satellite and a second LEO satellite.

29. The non-transitory computer-readable medium of claim 23, wherein execution of the instructions causes the controller to perform operations further comprising:

maintaining the return link between the first satellite and the user terminal before and after the handover operation.

30. An apparatus configured to switch forward link communications of a user terminal between first and second satellites, the apparatus comprising:

means for transmitting first data to the user terminal on a forward link of the first satellite;

means for transmitting time-division multiplexing (TDM) configuration information to the user terminal on the forward link of the first satellite, the TDM configuration information specifying a TDM transmission pattern for forward link communications to the user terminal from at least the first and second satellites;

means for switching forward link communications of the user terminal from the first satellite to the second satellite during a handover operation;

means for transmitting second data to the user terminal on a forward link of the second satellite after the handover operation; and

means for receiving one or more control or data messages from the user terminal on a return link of the first satellite after the handover operation.