Networked interactive call management subsystems with prevention of simultaneous use of a single account number

摘要

A telecommunications system allows multiple users to place and charge telephone calls to personal debit accounts without requiring specially designed telephones or "smart" cards. The system keeps track of the cost of each call, including applicable taxes, in real time and notifies the user when the account balance approaches zero. The system allows the user to restore the account balance in real time either manually or automatically by charging the increase to a commercial credit card. The system has multiple interactive call management subsystems, each subsystem having its own database. When one database in one subsystem is updated, signals are transmitted between subsystems to update every other database. An account in use flag is transmitted from a serving subsystem through a network to each of the other subsystems to prevent simultaneous use of an account.