Location determination method and system using multi-beam satellites
First Claim
1. A method of determining a user terminal location, comprising the steps of:
- (a) receiving, at said user terminal, a satellite signal comprising servicing beam information, said servicing beam information being unique to a servicing beam of a multi-beam satellite;
(b) processing, at said user terminal, a beam geometry and a geographical beam center as derived from said servicing beam information, said beam geometry describing a representation of the shape of said servicing beam, and said geographical beam center defining a geographical coordinate within said servicing beam; and
(c) calculating, at said user terminal, a user terminal region wherein said user terminal is located, said user terminal region defined by said beam geometry and said geographical beam center.
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Accused Products
Abstract
In a method and system for performing location determination using multi-beam satellites each beam of a multi-beam satellite transmits identification information which is received by a user terminal. This identification information either identifies the unique beam by enumeration or by geometrics. A user terminal processes multiple received signals from orbiting satellites. The user terminal maps the projected beam patterns of multiple received samples to determine an approximate self-location. The user terminal passively monitors its location and compares its current location with its previously reported location. When the user terminal has sufficiently roamed from its previously registered location, the user terminal performs an auto-registration to the system allowing for efficient routing of information.
92 Citations
19 Claims
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1. A method of determining a user terminal location, comprising the steps of:
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(a) receiving, at said user terminal, a satellite signal comprising servicing beam information, said servicing beam information being unique to a servicing beam of a multi-beam satellite; (b) processing, at said user terminal, a beam geometry and a geographical beam center as derived from said servicing beam information, said beam geometry describing a representation of the shape of said servicing beam, and said geographical beam center defining a geographical coordinate within said servicing beam; and (c) calculating, at said user terminal, a user terminal region wherein said user terminal is located, said user terminal region defined by said beam geometry and said geographical beam center.
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2. A method of determining when a user terminal should transmit its present location to a base station, comprising the steps of:
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(a) receiving, at said user terminal, a satellite signal comprising servicing beam information, said servicing beam information being unique to a servicing beam of a multi-beam satellite; (b) processing, at said user terminal, a beam geometry and a geographical beam center as derived from said servicing beam information, said beam geometry describing a representation of the shape of said servicing beam, and said geographical beam center defining a geographical coordinate within said servicing beam; (c) calculating, at said user terminal, a user terminal region wherein said user terminal is located, said user terminal region defined by said beam geometry and said geographical beam center, (d) comparing said user terminal region with a stored value of a last reported user terminal region; (e) transmitting said user terminal region if the distance between said user terminal region and said last reported user terminal region exceeds a predetermined roaming threshold; and (f) storing said user terminal region as a new value of said last reported user terminal region if said user terminal region was transmitted. - View Dependent Claims (3, 4, 5, 6, 7, 8)
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9. A method of determining when a user terminal should process location information transmitted by a multi-beam satellite system, comprising the steps of:
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(a) receiving, at said user terminal, a satellite signal comprising servicing beam information, said servicing beam information being unique to a servicing beam of a multi-beam satellite; (b) determining whether said servicing beam information provides diversity between said servicing beam information and previously received servicing beam information; (c) processing in response to determination of said diversity at said user terminal, a beam geometry and a geographical beam center as derived from said servicing beam information, said beam geometry describing a representation of the shape of said servicing beam, and said geographical beam center being a geographical coordinate within said servicing beam; and (d) calculating in response to determination of said diversity at said user terminal, a user terminal region wherein said user terminal is located. - View Dependent Claims (10, 11, 12)
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13. A telecommunication system for transmitting voice and data communications for delivering information to known subscribers by accurately knowing their present locations, said system comprising:
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a constellation of multi-beam satellites, said satellites transmitting servicing beam information, said servicing beam information providing location information defined by a beam geometry and a geographical beam center; a population of user terminals being capable of receiving and processing said servicing beam information; and a base station for maintaining a directory of said user terminals'"'"' most current location. - View Dependent Claims (14, 15, 16)
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17. A user terminal for use in a satellite-based communications system wherein at least one satellite transmits a servicing beam comprising servicing beam information, said servicing beam information comprising beam geometry for describing the shape of said servicing beam and a geographical beam center for describing a geographical coordinate within said servicing beam, said terminal comprising:
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means for receiving said servicing beam; means for processing said servicing beam to derive said beam geometry and said geographical beam center; and means for calculating a user terminal region wherein said terminal is located, using said beam geometry and said geographical beam center. - View Dependent Claims (18, 19)
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Specification