Patent ID: 7305245

Claim:
A method of locating a user-device having a Wi-Fi radio, comprising: providing a reference database of calculated locations of Wi-Fi access points in a target area; in response to a user application request to determine a location of a user-device having a Wi-Fi radio, triggering the Wi-Fi device to transmit a request to all Wi-Fi access points within range of the Wi-Fi device; receiving messages from the Wi-Fi access points within range of the Wi-Fi device, each message identifying the Wi-Fi access point sending the message; calculating the signal strength of the messages received by the Wi-Fi access points; accessing the reference database to obtain the calculated locations for the identified Wi-Fi access points; based on the number of Wi-Fi access points identified via received messages, choosing a corresponding location-determination algorithm from a plurality of location-determination algorithms, said chosen algorithm being suited for the number of identified Wi-Fi access points; using the calculated locations for the identified Wi-Fi access points and the signal strengths of said received messages and the chosen location-determination algorithm to determine the location of the user-device.