Location determination for mobile units
AssigneeMotorola, Inc.
InventorsPeter J. Armbruster, Keith A. Olds, David T. Gustafson
Life of this patent
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Abstract
A method for location determination using Bluetooth techniques is applicable within buildings, underground or within other structures. A mobile unit (10) seeks the location of a cell from location master (20). Location master (20) and a number of location subsidiaries (21-24) determine ranging information with regard to the mobile unit (10) using Bluetooth techniques. The location master (20) then determines the mobile unit location using least squares estimation or other triangulation methods (50). In an alternate embodiment, ranging information is fine tuned for noise and error measurements between the location master and the location subsidiaries (51, 53) are used.
Claims21
A location determination method for a mobile unit using Blutooth, the location determination method performed by a location master and a plurality of location subsidiaries, the location determination method comprising the steps of:
- measuring a first elapsed time, by the location master, between sent and received messages to the mobile unit;
- measuring at least one of second elapsed times, by the plurality of location subsidiaries, between sent and received messages to the mobile unit;
- and
- processing by the location master the first and second elapsed times to determine a location of the mobile unit.
A location determination method for a mobile unit using Bluetooth, the location determination method performed by a location master and a plurality of location subsidiaries, the location determination method comprising the steps of:
- measuring by the location master a clock timing between the location master and each of the plurality of location subsidiaries;
- measuring a first elapsed time by the location master between sent and received messages to the mobile unit;
- measuring a at least one of second elapsed times by the plurality of location subsidiaries, between sent and received messages to the mobile unit;
- and
- processing by the location master the first and second elapsed times to determine a location of the mobile unit.
The location determination method as claimed in claim 17, wherein there is further included the steps of:
- determining whether a sufficient number of the plurality of location subsidiaries has been used for measuring the plurality of second elapsed times;
- if an insufficient number of the plurality of location subsidiaries has been used, there is further included the steps of:
- selecting another location subsidiary;
- and
- iterating the steps of claims 17 and 18.
Dependencies are inferred from the claim text.