Dynamic beam fill-in system and method therefor

• US 6,269,242 B1
• Filed: 08/18/1999
• Issued: 07/31/2001
• Est. Priority Date: 08/18/1999
• Status: Expired due to Term

• Current Assignee: CDC Propriete Intellectuelle
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Laub, Jeffrey D., Morrow, Jeffrey C., Leopold, Raymond J.
• Primary Examiner(s): Chang, Vivian
• Assistant Examiner(s): NGUYEN, DUC M
• Application Number:
  US09/376,423
• Time in Patent Office: 713 Days
• Field of Search: 455/427, 455/429, 455/430, 455/12.1, 455/13-- 1, 455/8, 455/446, 455/447, 455/561, 455/562
• US Class Current: 455/427
• CPC Class Codes: H04B 7/2041 Spot beam multiple access

Abstract

A dynamic beam fill-in system (40) in a cellular communications network (20) having a constellation (22) of satellites (24) in orbit (26) with each satellite (24) having a plurality of antennas (30) configured to form cells (36) upon the surface (34) of the Earth. A first antenna (130) is configured to form a first cell (136) at a first location (144) for a first period (156) of time and at a second location (244) for a second period (256) of time. A second antenna (230) is configured to form a second cell (236) at least partially coincident with the first cell (136) during the first period (156). A third antenna (330) is configured to form a third cell (336) at least partially coincident with the first cell (136) during the second period (256). In the event of failure of the first antenna (130), a computer program (66), in response to a beam-replacement table (54), is configured to deactivate the first antenna (130) and activate the second antenna (230) during the first period (156) and the third antenna (330) during the second period (256).

Claims

1. A system for dynamic beam fill-in in a cellular communications network having a constellation of satellites in orbit above a surface of the Earth, said beam fill-in system comprising:

a first satellite in said constellation having a first antenna configured to form a first cell upon said surface of the Earth, wherein said first antenna is an active antenna;

a second satellite in said constellation having a second antenna configured to form a second cell upon said surface of the Earth, wherein said second cell is at least partially coincident with said first cell, and wherein said second antenna is an inactive antenna; and

a beam-replacement table associated with said first satellite and configured to identify said second satellite, wherein, in the event of a failure of said first antenna, said first satellite deactivates said first antenna and said second satellite activates said second antenna in response to said table.

2. A beam fill-in system as claimed in claim 1 additionally comprising:

a subject-beam identifier contained within said beam-replacement table and identifying said first antenna; and

a recovery-satellite identifier contained within said beam-replacement table, associated with said subject-beam identifier, and configured to identify said second satellite.

3. A beam fill-in system as claimed in claim 2 wherein said beam-replacement table is a first beam-replacement table, said system additionally comprising:

a recovery-beam identifier contained in one of said first beam-replacement table and a second beam-replacement table associated with said second satellite, said recovery-beam identifier being associated with said recovery-satellite identifier, and configured to identify said second antenna.

4. A beam fill-in system as claimed in claim 3 additionally comprising a computer program embodied on a computer-readable medium, said computer program comprising:

a first code segment for identifying said first antenna from said subject-beam identifier;

a second code segment for identifying said second satellite from said recovery-satellite identifier;

a third code segment for identifying said second antenna from said recovery-beam identifier;

a fourth code segment for deactivating said first antenna in response to said first code segment; and

a fifth code segment for activating said second antenna in response to said third code segment.

5. A beam fill-in system as claimed in claim 1 wherein:

said first satellite activates said first antenna for a predetermined period of time; and

said second antenna is configured to form said second cell during said predetermined period of time.

6. A beam fill-in system as claimed in claim 5 wherein said beam-replacement table comprises:

a time-period identifier configured to identify said predetermined period of time;

a subject-beam identifier associated with said time-period identifier and configured to identify said first antenna;

a recovery-satellite identifier associated with said subject-beam identifier and configured to identify said second satellite; and

a recovery-beam identifier associated with said recovery-satellite identifier and configured to identify said second antenna.

7. A beam fill-in system as claimed in claim 6 additionally comprising a computer program embodied on a computer-readable medium and configured to be executed in the event of said failure of said first antenna, said computer program comprising:

a first code segment for identifying said predetermined period of time from said time-period identifier;

a second code segment for identifying said first antenna from said subject-beam identifier associated with said time-period identifier;

a third code segment for identifying said second satellite from said recovery-satellite identifier associated with said subject-beam identifier;

a fourth code segment for identifying said second antenna from said recovery-beam identifier;

a fifth code segment for deactivating said first antenna for a remainder of said predetermined period of time in response to said second code segment; and

a sixth code segment for activating said second antenna for said remainder of said predetermined period of time in response to said fourth code segment.

8. A beam fill-in system as claimed in claim 1 wherein:

said system comprises a subconstellation of satellites within said constellation, wherein said satellites of said subconstellation have antennas configured to form cells at least partially coincident with said first cell; and

said beam-replacement table is configured to identify said second satellite as a satellite within said subconstellation having an antenna configured to produce a cell more coincident with said first cell than said cells of other satellites of said subconstellation are configured to produce.

9. A beam fill-in system as claimed in claim 1 wherein:

said first satellite forms said first cell at a plurality of locations upon said surface of the Earth during a plurality of predetermined periods of time;

others of said satellites form cells upon said surface of the Earth at least partially coincident with said first cell during said plurality of predetermined periods of time; and

said second satellite, during each of said plurality of predetermined periods of time, forms a cell more coincident with said first cell than said cells of said others of said satellites during each of said plurality of predetermined periods of time.

10. A method of providing dynamic beam fill-in for a cellular communications network having a constellation of satellites in orbit above a surface of the Earth, wherein each of said satellites has a plurality of antennas and each of said plurality of antennas is configured to form a cell upon said surface of the Earth, said beam fill-in method comprising:

a) activating, in a first satellite of said satellites, a first antenna configured to form a first cell upon said surface of the Earth;

b) deactivating, in a second satellite of said satellites, a second antenna configured to form a second cell upon said surface of the Earth at least partially coincident with said first cell;

c) detecting a failure of said first antenna;

d) identifying said second satellite;

e) deactivating said first antenna in response to said detecting operation c); and

f) activating said second antenna in response to said identifying operation d).

11. A beam fill-in method as claimed in claim 10 additionally comprising:

including, in a beam-replacement table in said first satellite, a subject-beam identifier configured to identify said first antenna; and

including, in said beam-replacement table, a recovery-satellite identifier associated with said subject-beam identifier and configured to identify said second satellite.

12. A beam fill-in method as claimed in claim 11 additionally comprising including, in said beam-replacement table, a recovery-beam identifier associated with said recovery-satellite identifier and configured to identify said second antenna.

13. A beam fill-in method as claimed in claim 10 additionally comprising:

incorporating a beam-replacement table within said first satellite;

including, in said beam-replacement table, a time-period identifier configured to identify a predetermined period of time during which said first antenna is configured to form said first cell;

including, in said beam-replacement table, a subject-beam identifier associated with said time-period identifier and configured to identify said first antenna;

including, in said beam-replacement table, a recovery-satellite identifier associated with said subject-beam identifier and configured to identify said second satellite; and

including, in said beam-replacement table, a recovery-beam identifier associated with said recovery-satellite identifier and configured to identify said second antenna.

14. A beam fill-in method as claimed in claim 13 wherein:

said deactivating operation e) deactivates said first antenna during said predetermined period of time; and

said activating operation f) activates said second antenna during said predetermined period of time.

15. A beam fill-in method as claimed in claim 10 wherein:

said activating operation a) activates said first antenna for a predetermined period of time;

said deactivating operation b) deactivates said second antenna for said predetermined period of time;

said detecting operation c) detects said failure of said first antenna during said predetermined period of time;

said deactivating operation e) deactivates said first antenna for a remainder of said predetermined period of time; and

said activating operation f) activates said second antenna for substantially said remainder of said predetermined period of time.

16. A system for dynamic beam fill-in in a cellular communications network having a constellation of satellites in orbit above a surface of the Earth, wherein each of said satellites has a plurality of antennas configured to form cells upon said surface of the Earth, said beam fill-in system comprising:

a first antenna configured to form a first cell at a first location upon said surface of the Earth for a first predetermined period of time and configured to form said first cell at a second location upon said surface of the Earth for a second predetermined period of time;

a second antenna configured to form a second cell upon said surface of the Earth at least partially coincident with said first cell for said first predetermined period of time;

a third antenna configured to form a third cell upon the surface of the Earth at least partially coincident with said first cell for said second predetermined period of time;

a beam-replacement table contained in a first computer-readable medium, configured to identify and associate said first antenna and said second antenna during said first predetermined period of time, and configured to identify and associate said first antenna and said third antenna during said second predetermined period of time; and

a computer program contained in a second computer-readable medium wherein, in response to said beam-replacement table, said computer program is configured to deactivate said first antenna and activate said second antenna in the event of a failure of said first antenna during said first predetermined period of time.

17. A beam fill-in system as claimed in claim 16 wherein said computer program is configured to deactivate, in response to said beam-replacement table, said first antenna and activate said third antenna in the event of said failure of said first antenna during said second predetermined period of time.

18. A beam fill-in system as claimed in claim 16 wherein:

said first antenna is activated at a beginning of said first predetermined period of time;

said second antenna is deactivated at said beginning of said first predetermined period of time; and

said third antenna is deactivated at a beginning of said second predetermined period of time.

19. A beam fill-in system as claimed in claim 16 wherein said beam-replacement table comprises:

a time-period identifier configured to identify each of said first predetermined period of time and said second predetermined period of time;

a subject-beam identifier associated with said time-period identifier and configured to identify said first antenna;

a recovery-satellite identifier associated with said subject-beam identifier and configured to identify which satellite of said constellation has said second antenna during said first predetermined period of time and said third antenna during said second predetermined period of time; and

a recovery-beam identifier associated with said recovery-satellite identifier and configured to identify said second antenna during said first predetermined period of time and said third antenna during said second predetermined period of time.

20. A beam fill-in system as claimed in claim 19 wherein said second computer-readable medium is located on a satellite having said first antenna.