Abstract: When an IP (Information Provider) server is accessed from a mobile station, a gateway server determines whether or not the IP server is to be IP billed. If it is not to be IP billed, then user billing is applied. In this case, the gateway server sends a user management number of the mobile station and the number of exchanged packets to a billing system. The billing system calculates a communication fee in accordance with the number of packets, and issues a bill to the user specified by the user management number. On the other hand, if the accessed IP server is to be IP billed, then IP billing is applied. In this case, the gateway server sends the number of exchanged packets and the address of the accessed IP server to the billing system. The billing system calculates a communication fee in accordance with the number of packets, and issues a bill to the IP.

Abstract: When information is delivered to a receiver mobile communication terminal, an update unit updates delivery status data stored in first storage, from “undelivered” to “delivered” in response to an update request from a relay when check permission data stored in second storage is “permitted.” When in this state a sender terminal issues a check request for the delivery status data, a sending unit sends the delivery status data of “delivered” status to the sender terminal. When the check permission data is set as “prohibited,” the delivery status data is not updated to the delivered status even if the receiver has received the information.

Abstract: When an IP (Information Provider) server is accessed from a mobile station, a gateway server determines whether or not the IP server is to be IP billed (S101). If it is not to be IP billed, then user billing is applied. In this case, the gateway server sends a user management number of the mobile station and the number of exchanged packets to a billing system (S102). The billing system calculates a communication fee in accordance with the number of packets, and issues a bill to the user specified by the user management number (S103). On the other hand, if the accessed IP server is to be IP billed, then IP billing is applied. In this case, the gateway server sends the number of exchanged packets and the address of the accessed IP server to the billing system (S104). The billing system calculates a communication fee in accordance with the number of packets, and issues a bill to the IP (S105).

Abstract: When information is delivered to a receiver mobile communication terminal, an update unit updates delivery status data stored in first storage, from “undelivered” to “delivered” in response to an update request from a relay when check permission data stored in second storage is “permitted.” When in this state a sender terminal issues a check request for the delivery status data, a sending unit sends the delivery status data of “delivered” status to the sender terminal. When the check permission data is set as “prohibited,” the delivery status data is not updated to the delivered status even if the receiver has received the information.