Patent ID: 7345630

Claim:
A server apparatus of a terminal position detection system including a terminal apparatus, a plurality of base stations in radio communication with the terminal, and a server apparatus connected to a plurality of the base stations, the server apparatus comprising: a position detection process portion configured to detect a position of the terminal apparatus through at least a first or second position detection process; and a storage apparatus including a measurement information database, wherein the server apparatus includes a position detection process portion and a storage apparatus having a received power measurement information database, wherein the position detection process portion is configured to detect a position of the terminal apparatus through at least one of a first or second position detection process, wherein the first position detection process includes receiving at others of the plurality of base stations signals transferred between one of the plurality of base stations and the terminal apparatus, collecting at the server apparatus information about reception timings of the signals received at each of the others of the plurality base stations, and calculating a position of the terminal apparatus using a plurality of the reception timings and position information about the others of the plurality of base stations, wherein the second detection process includes collection at the server apparatus measurement information about received powers of signals transferred between the terminal apparatus and the others of the plurality of base stations, and searching a received power measurement information database previously stored in the server apparatus using a plurality of the measurement information about the received powers, and determining a position of the terminal apparatus based on the searching, wherein the position information and received power measurement information corresponding to the position information are stored in the received power measurement information database, the position information being obtained by at least one of the first position detection process and the second position detection process, and the received power measurement information being the received powers of the signals corresponding to the plurality of base stations in response to that the terminal apparatus is detected to be at the position indicated by said position information, wherein the position detection process portion includes determining whether to execute the second position detection process according to the information stored in the received power measurement information database, and wherein the first position detection process for each of adequate terminals is executed according to judgment of the server so that the measurement information database about the received powers is structured even in case that there is no position request from the terminal until enough of the measurement information database about the received powers is structured in an initial state.