| 摘要 |
PURPOSE:To realize position detecting service in the same system as usual radiotelephony by transmitting the position detection signals from three or more radio base stations and detecting the position of a moving body from the time lag from the transmission to the reception of response signals. CONSTITUTION:A moving body 101 and the data switching apparatus 203 of a radio telephony master base station A are connected through a switchboard 202 on the basis of the specific phone number from the radio telephone of the moving body 101 and, at the same time, the communication paths to adjacent radio telephony sub-base stations B, C are opened. The main station A transmits a position detection pulse signal to the moving body 101 and also transmits a pulse to the moving body 101 through the sub-stations B, C at the same time and the response pulse thereof is received by the apparatus 203 and the time lag from the transmission of the position detection signals between the respective stations and the moving body 101 to the reception of the response signals thereof is inputted to a position calculator 204 to calculate the position of the moving body 101 and inform the radio telephone of the moving body 101 of this position. By this method, a detected position can be provided without altering the constitution on the side of the moving body 101 and increasing processing thereof. |
