US Patent 10145689 Method and system of pedestrian localization

A method and system localizing a mobile device along a pedestrian route traversed in an indoor area, the mobile device including a processor and a memory. The method executed in the processor and comprises localizing the mobile device to an estimated first position within the indoor area based on accessing, from a first memory tier of the memory, a first portion fingerprint data that includes fingerprint data of a first subset area of the indoor area, the first subset area at least partly surrounding the estimated first position, detecting a traversal of the mobile device along the route to an estimated second position within the indoor area, and when a difference between the estimated first and second positions exceeds a threshold distance, replacing the first portion fingerprint data of the first memory tier upon pre-fetching a second portion fingerprint data, the second portion fingerprint data including fingerprint data of a second subset area of the indoor area, the second subset area at least partly surrounding the estimated second position.