Patent ID: 7711376

Claim:
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.