| 摘要 |
PROBLEM TO BE SOLVED: To prevent the increase of utility charges in data communication under a mobile environment by a proper connection time of a line. SOLUTION: After acquiring a radio wave state from a communication interface (601), data transfer is started (602). On the occurrence of a change of a radio wave state (603), data transfer is temporarily interrupted (604), and a transfer time relating to a data quantity which has been transferred up to the change depending on the radio wave state is acquired (605). When the radio wave state after the change becomes excellent, the data transfer is restarted (609), and when the radio wave state after the change is not excellent, the sum of line utility charge obtained by the data quantity and the radio wave state before the change and a line utility charge obtained by the data quantity and the radio wave state after the change (former) and a line utility charge obtained by the total data quantity and the radio wave state before the change (latter) are calculated (607), both line utility charges are compared (608), and when the line utility charge of the former is not higher than the line utility charge of the latter, data transfer is restarted (610) and when the line utility charge of the former is higher than the line utility charge of the latter, the line is interrupted (611). |
