| 摘要 |
PROBLEM TO BE SOLVED: To enable a man to easily obtain position information and easily know the case deviating from an area by receiving position information from a plurality of sign posts. SOLUTION: A sign post 1 is provide with an antenna 2 for transmission and reception, a transmission part 4 and a reception part 5 respectively connected to a shared device 3, a memory 7 storing a program, and a memory 8 for data. The sign posts 1 are provided with intervals of hundreds meters, for example along a mountain climbing route. Each of sign posts 1 transmits area numbers, for example at a certain time interval as position information indicating a specific area. On the other hand, on a liquid crystal panel of a portable wireless terminal, an area number indication part and total sign post number indication part of the sign posts 1 are provided. A mountain climber can easily catch the self-position in the mountain climbing route. When the reception from the sign posts 1 ceased, alarm sound is generated after elapsing a predetermined time. As the situation deviating from a specific area can be easily recognized, safety in mountain climbing, for example, is improved. |
