Flexible real-time payment methods for mobile communications

The method of billing-users for mobile telephony is based on systems develo ped over time for fixed networks. We survey the technology involved, and ar gue that these systems will become increasingly inadequate for large popula tions of mobile users where frequent roaming is involved. We present two mi cropayment schemes which permit a caller to inject a payment stream into th e network which allows multiple network operators and value-added service p roviders to be paid in real time. The methods support dynamic pricing by th e association of a pricing contract with the call which specifies the cost for each leg of the call route. The system Frill alleviate problems of mobi le fraud, eliminate the need for interoperator billing agreements, and simp lify payment for value-added network services. We discuss the relative meri ts of the two systems described and the characteristics of the prototype im plementation.