| 摘要 |
PROBLEM TO BE SOLVED: To display a map around a user, even when the user stays outside a radio communication service zone of a portable telephone and within a geographically strange place, such as a foreign country.SOLUTION: A user downloads in advance desired preliminary map information from a map information providing server 40 via a radio base station 30 or a PC 50 to an external memory 11 of a portable telephone 10. When the user approaches a destination, current position information is obtained by a GPS function. If there exists the preliminary map information matched with position information in the downloaded preliminary map information, the preliminary map information is displayed on the portable telephone 10. If there does not exist any preliminary map information matched with the position information, the fact is displayed, and after the user moves, position measurement is performed again. |
