Prepaid Service for Voice over GPRS

Abstract

This paper proposes a prepaid mechanism for wireless voice over IP (VoIP) service. Based on General Radio Packet Data (GPRS), we consider the wireless VoIP environment proposed in 3GPP TR21.978. In our proposal, a prepaid service center is introduced to maintain the credits of the prepaid customers. We use H.323 protocol to implement prepaid mechanism including prepaid customer registration, credit decrement (and forced termination due to credit depletion), and credit recharge.