Method of providing location service using CDMA-based cellular phone system, a method of measuring location and location system
First Claim
1. A method of furnishing a location service comprising:
- transmitting a specific signal pattern at given intervals from at least three base stations, wherein a location of a mobile terminal or station that receives said signal pattern is located by using positional information about said base stations, sending timing or information on a phase shift from reference time of each said signal pattern from said base stations, and signal pattern receiving time information;
deliberately making a change to the sending timing of said signal pattern from at least one of said base stations; and
responsive to the change of the sending timing of the signal pattern, notifying said mobile terminal or station of an altered reference time offset or information on a phase shift from the reference time of said sending timing or updated sending timing of said signal pattern;
wherein if a request is issued from said mobile terminal or station to at least one of said base stations while the sending timing of said signal pattern is changed, a message representing that a location determination is not possible is sent to said mobile terminal or station.
1 Assignment
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Accused Products
Abstract
At least three base stations transmit a specific signal pattern at given intervals. This allows a mobile station that received this signal pattern to locate itself by using the positional information about the base stations, sending timing (or information on phase shift from the reference time) of each signal pattern from the base stations, and signal pattern receiving time information. At least one of the above base stations changes the sending timing of the signal pattern. On this occasion, the mobile terminal or station is notified of the altered reference time offset (or information on phase shift from the reference time) of the sending timing or updated sending timing of the signal pattern.
29 Citations
23 Claims
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1. A method of furnishing a location service comprising:
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transmitting a specific signal pattern at given intervals from at least three base stations, wherein a location of a mobile terminal or station that receives said signal pattern is located by using positional information about said base stations, sending timing or information on a phase shift from reference time of each said signal pattern from said base stations, and signal pattern receiving time information; deliberately making a change to the sending timing of said signal pattern from at least one of said base stations; and responsive to the change of the sending timing of the signal pattern, notifying said mobile terminal or station of an altered reference time offset or information on a phase shift from the reference time of said sending timing or updated sending timing of said signal pattern; wherein if a request is issued from said mobile terminal or station to at least one of said base stations while the sending timing of said signal pattern is changed, a message representing that a location determination is not possible is sent to said mobile terminal or station. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A method of furnishing a location service wherein a location of a mobile terminal or station is determined using sending timing of signal patterns transmitted from a plurality of base stations, and receiving timing of said signal patterns at the mobile terminal or station, the method comprising the steps of:
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deliberately making a change to the sending timing of a specific signal pattern of radio waves transmitted at given intervals from a base station regularly; and notifying the mobile terminal or station of an altered reference time offset of said sending timing or updated sending timing of said signal pattern; wherein if a request is issued from said mobile terminal or station to at least one of said base stations while the sending timing of said signal pattern is changed, a message representing that a location determination is not possible is sent to said mobile terminal or station. - View Dependent Claims (10, 11, 12, 13)
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14. A method of furnishing a location service comprising:
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deliberately making a change to the sending timing of a specific signal pattern of radio waves transmitted at given intervals from a base station regularly or at irregular intervals; calculating the location of a mobile terminal or station, based on the receiving timing of said signal pattern received at said mobile terminal or station; and notifying said mobile terminal or station of a result of the calculating step; wherein if a request is issued from said mobile terminal or station while the sending timing of said signal pattern is changed, a message representing that a location determination is not possible is sent to said mobile terminal or station. - View Dependent Claims (15, 16, 17)
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18. A method for locating a mobile terminal or station comprising the steps of:
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sending an ID of the mobile terminal or station, and a request for information on the sending timing of a specific signal pattern transmitted at given intervals from base stations in the vicinity of the mobile terminal or station to a base station in a zone in which the mobile terminal or station locates; and determining a location of the mobile terminal or station based on an answer from said base station in the zone in which the mobile terminal or station locates, and respective receiving timing of the signal pattern from each of said base stations in the vicinity of the mobile terminal or station; wherein if a request is issued from said mobile terminal or station to at least one of said base stations while a sending timing of said signal pattern is changed, a message representing that a location determination is not possible is sent to said mobile terminal or station. - View Dependent Claims (19)
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20. A location system comprising at least three base stations and one mobile terminal or station, wherein:
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said base stations transmit a specific signal pattern at given intervals; at least one of said base stations deliberately changes the sending timing of said signal pattern; said base stations broadcast encrypted information on sending timing of said signal pattern transmitted from the base stations over at least one broadcast channel or control channel; and said mobile terminal or station decrypts the encrypted information on sending timing of said signal pattern transmitted from base stations located in the vicinity of the mobile terminal or station by using a decrypting key, and determines a location of the mobile terminal or station based on the decrypted information, positional information about said base stations, and information related to receiving timing of each said signal pattern from said base stations; wherein if a request is issued from said mobile terminal or station to at least one of said base stations while the sending timing of said signal pattern is changed, a message representing that a location determination is not possible is sent to said mobile terminal or station.
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21. A location system comprising at least three base stations and one mobile terminal or station, wherein:
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said base stations transmit a specific signal pattern at given intervals; at least one of said base stations deliberately changes the sending timing of said signal pattern; and said mobile terminal or station determines a location of the mobile terminal or station based on an altered reference time offset associated with the changed sending timing of said signal pattern or updated sending timing of said signal pattern, positional information about said base stations, and information on receiving timing of each said signal pattern from said base stations; wherein if a request is issued from said mobile terminal or station to at least one of said base stations while the sending timing of said signal pattern is changed, a message representing that a location determination is not possible is sent to said mobile terminal or station. - View Dependent Claims (22, 23)
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Specification