Determining the physical location of a mobile wireless device. A computer receives 1-hop and 2-hop neighbor information from a mobile wireless device for neighbor devices of the mobile wireless device responding to a discovery request transmitted by the mobile wireless device in an ad hoc wireless communications protocol. The computer determines a physical location of the mobile wireless device based in part on stored fixed physical locations of responding devices; an area in which the mobile wireless device is in range of responding 1-hop neighbors associated with a fixed physical location; and an area in which the mobile wireless device is in range of responding 1-hop neighbors not associated with a fixed physical location, which are in the range of 2-hop neighbors associated with fixed physical locations.