| 摘要 |
PROBLEM TO BE SOLVED: To inhibit speaking inside the car of train or passenger car in traveling. SOLUTION: A call is originated at every predetermined time, based on the traveling speed of a vehicle, under the control of a CPU 15, the area information of a base station responding to that originated call is acquired and stored in a memory 18, a judgement part 17 judges whether the area information stored in the memory 18 is equal with area information acquired after the lapse of the next prescribed time or not and when it is judged the area information is equal, wireless speaking is made valid but when it is judged the area information is not equal, wireless speaking is made invalid even when a call is originated or terminated. |
