| 摘要 |
PROBLEM TO BE SOLVED: To inform a talking party of how much a call charge reaches for each call without offending the party. SOLUTION: When a number of 'X#' + 'telephone number' is entered by a portable telephone set (step 101), the system stores the number 'x' as a scheduled limit amount (step 201), and continue to calculate a call charge (y) after the start of the call (step 204). When a residual amount being subtraction of the call charge (y) from the scheduled limit amount (x) reaches a prescribed value z0 or below, the system sends a warning message to the portable telephone set (step 211) to allow the portable telephone set to display (voice output) it. Thus, the system informs the user of the present situation that the call charge reaches the scheduled limit amount (step 103), when the call can be maintained. |
