US Patent 9078229 Base station location derived from wireless terminal information

A technique for deriving the locations of one or more wireless base stations is disclosed. After initializing values for the base station location coordinates, a server acquires reference coordinates of a wireless terminal, which are provided from an independent source, and also acquires values for one or more time-of-occurrences of events associated with signals that travel between the wireless terminal and the base stations. The server generates predicted coordinates of the wireless terminal, based in part on the current base station coordinates, by using trilateration. The server then generates updated base station coordinate values, based on a method of least squares, in which each residual is a difference between the reference and predicted coordinates of each wireless terminal location, for one or more wireless terminals. The server modifies the base station coordinate values so as to minimize the least-squares function.