A radiocommunication system including a portable terminal, a base station and a server. The portable terminal transmits a destination to the server and further sends the ID number (CS_ID) of the base station coupled through a radio link to the portable terminal. The server has a table representative of a corresponding relationship between the ID number of the base station and the standing position of the base station and retrieves the position corresponding to the ID number thereof as the present position of the portable terminal from the table. Further, the server transmits map data corresponding to the present position of the portable terminal to the portable terminal.