Methods, apparatus, and computer program products for determining a mobile device location. An example of a method for determining a mobile device location includes receiving signals from a transmitter, measuring signal characteristics of the received signals, and downloading data from a database corresponding to a defined region associated with the transmitters. The downloaded data includes a set of position points, a classification of each position point, and expected signal characteristics for each position point. The method further includes comparing the measured signal characteristics with the expected signal characteristics for each position point, assigning a weight to position points based on the compared signal characteristics, and determining the mobile device location by selecting one position point from the set as a position point solution corresponding to the mobile device location based on the assigned weight. The position point solution is constrained by the classification of each position point.