Patent ID: 8078194

Claim:
A device for assisting locating a mobile radio device, the device being a network device in wireless communication with the mobile radio device via a wireless network, comprising: a table maintaining signal measurement data for each of a plurality of broadcast radio signal sources, the broadcast radio signal sources broadcasting radio signals within the FM frequency band, the signal measurement data corresponding to a plurality of previously measured signal quality information indicating associated radial distances from the broadcast radio signal sources; and processing circuitry for: determining respective source locations of each of three or more broadcast radio signal sources, receiving signal quality characteristics measured by the mobile radio device for each of the broadcast radio signals from each of the three or more broadcast radio signal sources, comparing the respective signal quality characteristics to the table to identify respective radial distances from the three or more broadcast radio signal sources, and calculating geographical coordinates representing a mobile location of the mobile radio device using the identified radial distances and the source locations.