摘要 |
A first position and second position at first point in time and second point in time are specified, information on planned moving route starting from the first position is stored, an option list having options in different viewpoints are stored regarding frequency selection policies in selecting frequency to be used, the route information and the option list are transmitted to database, an information list on effective frequencies listed corresponding to respective points in the route information and the options is received from the database, it is determined to which point out of the points the second position is close, appropriate option is selected from the option list as policy to be applied, frequency listed in correspondence to the point close to the second position out of the points and the policy to be applied is selected from the effective frequency information list. |