1. A method comprising: obtaining, from a memory, a digital map of an indoor region that identifies boundaries between subsections within the indoor region; extracting feature labels from the digital map and establishing points based on locations of the extracted feature labels; approximating locations of walls separating rooms within at least one of the subsections by superimposing polygons over the subsections within the indoor region based on the established points; and generating heat map values at a plurality of points within at least one subsection based on an estimated number of walls crossed between the plurality of points and at least one transceiver.