To performing positioning automatically and certainly, capable of remote control using a GPS(Global Positioning System).

A GPS receiver is communicated with an administration center 100 via a portable telephone terminal 101. The center 100 is connected to a telephone set 104 of a housing 103 and a facsimile machine 105 via a telephone line. The telephone set 104 is button-operated, and position information of the receiver 102 is requested for the center 100. A position information request is transmitted from the center 100 to the receiver 102 via a DTMF(dial tone multiple frequency) signal. Positioning is performed by the receiver 102, and the positioning results and time information of a navigation message used for positioning are transmitted to the center 100 via the DTMF signal. At the center 100, correction of positioning results is performed if a message is old based upon the time information. Position information is notified from the center 100 to the telephone set 104. Image data together with map information is notified to the facsimile machine 105.