Patent ID: 7551929

Claim:
A method for facilitating the determination of a speed of travel of the Wi-Fi enabled device within a location-based services system having a reference database of Wi-Fi access points in a target area, each Wi-Fi access point in the target area positioned at a corresponding geographical location, the method comprising: the Wi-Fi enabled device receiving signals transmitted by Wi-Fi access points in range of the Wi-Fi enabled device during a window of time; accessing the reference database to retrieve the corresponding geographical locations of the identified Wi-Fi access points; using the geographical locations of the identified Wi-Fi access points to estimate a plurality of positions of the Wi-Fi enabled device occurring during the window of time; associating a time value with each of the estimated positions, each time value and position estimate forming one position/time pair of a plurality of pairs, the plurality having a first position occurring at a first time and a second position occurring at a second time; calculating a lower speed bound based on a difference between the first position and time and second position and time; calculating a plurality of speeds based on differences between consecutive pairs of the plurality of position/time pairs; selecting as an upper speed bound the median speed from the plurality of speeds; and calculating a speed of travel of the Wi-Fi enabled device based on the median speed of the plurality of speeds and the first speed.