Multi-beam satellite communications system
First Claim
1. A satellite communications system for distributing information to user terminals located within a plurality of spot beams, the satellite communications system comprising:
- a communications satellite in a geosynchronous orbit;
a plurality of hubs each located within a respective spot beam, and adapted to;
route information received from a first user terminal located within a first spot beam via the communications satellite to a second user terminal located within a selected one of the spot beams via the communications satellite;
wherein the communications satellite is adapted to;
receive the information according to a first protocol from the first user terminal;
transmit the information according to the first protocol to a first hub located within a selected one of the spot beams;
receive the information according to a second protocol from the first hub; and
transmit the information according to the second protocol to a second user terminal located within a selected one of the spot beams.
2 Assignments
0 Petitions
Accused Products
Abstract
A satellite communications system having ground user terminals, hubs, and a geosynchronous satellite. The satellite generates a network of spot beam coverage areas on the earth. A hub and at least one ground terminal are located in each of at least two spot beams. A first user terminal transmits an uplink signal according to a first signal protocol to the hub through the satellite. A second user terminal receives a downlink signal according to a second signal protocol through the downlink spot beam from the hub through the satellite. The hub may be located in the same spot beam coverage area as the first or the second user terminal or may be located in an altogether different spot beam coverage area. Through selective frequency and/or polarization routing on board the satellite, a hub located within a “parent” beam can communicate with user terminals within the parent beam at a specified frequency and polarization, and can communicate with users in other “dependent” beams on a different frequency and/or polarization. This routing allocates the total available bandwidth between parent and dependent beams. The system enables asynchronous communications between each hub and the satellite to maximize frequency re-use and the overall capacity of the system.
86 Citations
27 Claims
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1. A satellite communications system for distributing information to user terminals located within a plurality of spot beams, the satellite communications system comprising:
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a communications satellite in a geosynchronous orbit;
a plurality of hubs each located within a respective spot beam, and adapted to;
route information received from a first user terminal located within a first spot beam via the communications satellite to a second user terminal located within a selected one of the spot beams via the communications satellite;
wherein the communications satellite is adapted to;
receive the information according to a first protocol from the first user terminal;
transmit the information according to the first protocol to a first hub located within a selected one of the spot beams;
receive the information according to a second protocol from the first hub; and
transmit the information according to the second protocol to a second user terminal located within a selected one of the spot beams. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A user terminal for communicating information with other user terminals through a satellite communications system, the satellite communications system including a communications satellite in geosynchronous orbit and a plurality of hubs, the communications satellite including an antenna, each hub located in one of a plurality of spot coverage areas formed by the antenna, the user terminal being adapted to:
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transmit information to one of the hubs via the communications satellite according to a first protocol; and
receive information from the hub via the communications satellite according to a second protocol. - View Dependent Claims (13, 14, 15)
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16. A method for communicating between user terminals through hubs, the user terminals being located in spot coverage areas defined by a spot beam antenna on a geosynchronous communications satellite, each of the hubs located in a respective spot coverage area, the method comprising the steps of:
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transmitting a first signal from a first user terminal to a hub through the satellite according to a first protocol; and
receiving a second signal at a second user terminal from the first hub through the satellite according to a second protocol. - View Dependent Claims (17, 18, 19, 20, 21, 22, 23, 24)
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25. A frequency-based router circuit for use in a satellite communications system, the satellite communications system comprising a ground hub;
- a communications satellite; and
a plurality of user terminals located in a plurality of spot coverage areas,the router circuit comprising;
a first demultiplexer for separating an inter-beam signal from a plurality of intra-beam signals;
a second demultiplexer for separating the intra-beam signals; and
a router adapted to route each of the inter-beam signal and the intra-beam signals to respective spot beam antennas on the satellite. - View Dependent Claims (26, 27)
- a communications satellite; and
Specification