Location of wireless mobile terminals

A computer-implemented method of updating a database having characteristics of a plurality of wireless network transmitters comprising the steps of:

• receiving a report from a mobile radio terminal, wherein the report includes one or more measurements of at least one radio parameter corresponding to a first wireless network transmitter;
• and one or more measurements of at least one radio parameter corresponding to a second wireless network transmitter;
• estimating a location for the radio terminal based at least in part on the report and characteristics corresponding to the first and second wireless transmitters;
• and
• estimating or updating a set of characteristics for the first wireless network transmitter based at least in part on the reported measurements and the estimated location.

A processing system that is capable of determining a location of a radio terminal comprising:

• at least one wireless network comprising a plurality of wireless network transmitters;
• at least one mobile radio terminal in communication with said at least one wireless network;
• at least one database containing characteristics corresponding to transmitters of said at least one wireless network;
• wherein the processing system is configured to execute steps comprising:
• measuring in a mobile radio terminal one or more radio network parameter corresponding to at least one wireless network transmitter;
• receiving at a server the radio network parameter measurements;
• applying a cost function to the one or more measurements and one or more characteristics corresponding to the at least one wireless network transmitter;
• and
• minimizing a sum of costs generated by the cost function to calculate the location of the mobile radio terminal.

A computer-implemented method of discovering and/or maintaining wireless transmitter characteristics for wireless transmitters in a wireless network comprising the steps of:

• receiving from a mobile radio terminal, at least one measurement of at least one radio parameter corresponding to a first wireless transmitter and at least one measurement of at least one radio parameter corresponding to at least one other wireless transmitter;
• retrieving a set of characteristics for the at least one other transmitter from a database;
• and
• estimating or updating in a processing system a set of characteristics for the first wireless transmitter based at least in part on the characteristics of the at least one other transmitter, and the collected measurements corresponding to the first wireless transmitter and the at least one other wireless transmitter.