A mobile station requests a start of positioning and receives a response of positioning
from a positioning server, following which it informs the positioning server of
its own station information and neighboring base station information gathered through
searching the neighboring base stations. Thereby, the mobile station receives assistant
information regarding GPS satellites to be captured based on a station location
designated by the positioning server and then it measures a GPS signal and a base
station signal such as an apparent signal delay. In the case that the positioning
information collected as described above is sufficient for location computing,
it displays the location computed by the positioning server. In contrast, in the
case that the positioning information is insufficient, it displays "positioning
impossible" without sending the positioning information to the positioning server.