| 摘要 |
PROBLEM TO BE SOLVED: To provide a information system provided with a small type portable terminal for informing that the user is in a danger area. SOLUTION: This information system comprises a portable terminal 2, a first information center 20, and a second information center 30. The portable terminal 2 obtains its own position information from the first information center 20, and sends the position information to the second information center 30. The second information center 30 sends an alarm message to the portable terminal 2, when the center 30 determines that the position information is close to self-possessing dangerous area information. |
