DETERMINING USER DEVICE'S STARTING LOCATION

摘要

A user device is equipped with one or more sensors that collect data relating to a movement of a user having the user device. An estimated area within which a starting location of the user device is located is determined based on one or more signals received from adjacent signal sources. A plurality of candidate locations is identified within the estimated area as the potential starting location of the user device. Map information of surrounding area that covers the estimated area is also obtained. One or more candidate locations are filtered out depending on whether they could have experienced the movement based on the map information. When one or more re-starting conditions have met during the movement, a then starting location of the user device needs to be determined.