Methods, program products, and systems for managing a location database are described. A server computer can receive location information from location-aware mobile devices (e.g., GPS-enabled devices) located within a communication range of access points of a wireless communications network. The server computer can calculate average geographic locations using the received locations for each access point. Based on the average geographic locations, the server computer can assign the access points to cells of a geographic grid. The server computer can filter the access points in each cell based on popularity, stability, longevity, and freshness of the access point and the received data. When a second mobile device connects to an access point in a cell, the server computer can transmit locations of the access points in the cell and in neighboring cells to the second mobile device such that a location of the second mobile device can be estimated.