Instead of requiring a customer to carry around one or more prepaid telephone calling cards (such cards are effectively functioning as limited, fixed amounts of money), a communications network-based solution is provided that facilitates both prepayment and use of prepay telecommunications services....http://www.google.fr/patents/US6333976?utm_source=gb-gplus-shareBrevet US6333976 - Method and apparatus for providing prepaid telecommunications services
Method and apparatus for providing prepaid telecommunications services
