US Patent 7573991 Communication control system and communication control method

A first communication control system comprising a balance database for storing the prepaid money of each per caller number, a charge database for storing the charge system of each communication company, a balance checking part for checking the balance by searching the balance database with the caller number, a call permission determining part for determining the permission of a call of the caller based on the balance, a communication company specifying part for specifying one communication company based on the input number from a caller terminal, a line switch and a line control part for connecting the caller terminal with a called terminal through an exchange of the specified communication company, a speech time measuring part for measuring the speech time, a telephone charge calculating part for calculating the speech time and the telephone charge according to the charge system of the communication company, and a balance updating part for subtracting the telephone charge from the balance of the caller.