Method and system for preventing sun transit outages in point-to-multipoint satellite systems

• US 7,006,788 B1
• Filed: 12/18/1998
• Issued: 02/28/2006
• Est. Priority Date: 12/11/1997
• Status: Expired due to Fees

• Current Assignee: Dyncorp Information Systems LLC
• Original Assignee: Dyncorp Information Systems LLC
• Inventors: Warren, Richard H.
• Primary Examiner(s): MEHRPOUR, NAGHMEH
• Application Number:
  US09/216,036
• Time in Patent Office: 2,629 Days
• Field of Search: 455/12.1, 455/13.1, 455/13.3, 455/25, 455/427, 455/428, 455/32, 455/13.2, 455/8, 455/9, 455/14, 455/15, 455/3.02, 455/63.4, 342/359, 342/354, 342/350, 342/75, 342/74
• US Class Current: 455/12.1
• CPC Class Codes: H04B 7/18515 Transmission equipment in satellites or space-based relays
• CPC Class Codes: H04B 7/18534 for enhancing link reliablility, e.g. satellites diversity
• CPC Class Codes: H04B 7/19 Earth-synchronous stations

Abstract

A geostationary communication satellite system that uses a hub and spoke configuration, where the hub includes at least one relatively large diameter satellite antenna. The hub of the communication system is capable of receiving satellite communication signals even when the sun transits within the beamwidth of its primary antenna by either redirecting its primary antenna toward a secondary satellite, or switching to a secondary antenna directed toward a secondary satellite.

Claims

1. A point-to-multipoint satellite communication system, comprising:

a first directional satellite antenna for generating a wide beam communication signal to illuminate a plurality of satellites;

means for generating a return communication signal from each of the plurality of satellites;

a second satellite antenna, directed to a first one of the plurality of satellites, for receiving said return communication signal from said first satellite; and

a third satellite antenna, directed to a second one of the plurality of satellites located proximate to said first satellite, for receiving said return communication signal from said second satellite only during sun transit outages of said second antenna.

2. The system of claim 1, wherein a diameter of the second and third satellite antennas are greater than a diameter of the first satellite antenna.

3. A method of performing satellite communication in a point-to-multipoint communications system,

comprising the steps of:

aligning a first satellite antenna to illuminate a plurality of satellites;

transmitting a communication signal from the first satellite antenna to said plurality of satellites;

broadcasting a return signal from each of said plurality of satellites based on the transmitted communication signal;

aligning a second satellite antenna to receive the return signal from only a first one of the plurality of satellites;

repositioning said second satellite antenna to receive the return signal from only a second of the plurality of satellites during periods when the sun transits behind said first satellite; and

receiving the return signal from said second satellite at said second satellite antenna during said periods.

4. A method of performing satellite communication in a point-to-multipoint communication system, comprising the steps of:

aligning a first antenna to illuminate a plurality of satellites;

transmitting a communication signal from said first antenna to the plurality of satellites;

broadcasting a return signal from each of the plurality of satellites in response to the communication signal;

aligning a second antenna to receive the return signal from a first one of the plurality of satellites;

receiving the return signal from said first satellite at said second antenna when the sun is outside the beamwidth of said second antenna;

aligning a third antenna to receive the return signal from a second one of the plurality of satellites; and

receiving the return signal from said second satellite with said third antenna when the sun is within the beam width of said first satellite.

5. An earth station for use in a point-to-multipoint communication system including a small satellite antenna for transmitting a wide beam communication signal and a plurality of adjacent geostationary satellites for retransmitting the communication signal from the small satellite antenna, the earth station comprising;

a first large satellite antenna directed to a first one of the plurality of adjacent geostationary satellites;

a second large satellite antenna directed to a second one of the plurality of adjacent geostationary satellites; and

a receiver for receiving communication signals at one of the said first and second antennas, said receiver including an antenna switch selector for selectively activating said first and said second antennas, the selector activating the second antenna only during periods when the sun transits within a beamwidth of said first antenna.