System and method of charging for user traffic except signaling a wireless communication system

1. A method of charging a user equipment (UE) in a gateway node in a mobile communication system, comprising the steps of:

providing a serving support node within a radio network connected to the UE and the gateway node for connecting the radio network to a home server in an external network;

acquiring from the external network the address of a home server that provides a service requested by the UE; and

storing the home server address, clearing charging information collected with respect to signaling generated prior to the allocation of the home server address, and re-collecting charging information about the service that the UE receives.

2. The method of claim 1 , further comprising the step of transmitting a message comprising the home server address to the serving support node to provide a reference time of collecting the charging information.

3. The method of claim 2 , wherein the message is an update packet data protocol (PDP) context request message including an end user address (EUA) with the home server address.

4. The method of claim 1 , wherein the acquiring step comprises the step of, when the UE requests a mobile internet protocol (IP) service, receiving a message including the home server address from the home server that provides the mobile IP service, after PDP activation with the UE.

5. The method of claim 4 , wherein the message is a mobile IP registration response message.

6. The method of claim 1 , wherein the acquiring step comprises the step of, when the UE requests a layer 2 tunneling protocol (L2TP) service, acquiring the home server address from an Internet protocol control protocol (IPCP) authentication message transmitted through the gateway node between the UE and the home server that provides the L2TP service, after PDP activation with the UE.

7. The method of claim 1 , further comprising the step of transmitting the charging information re-collected by the gateway node to a billing server.

8. A method of charging a user equipment (UE) in a serving support node in a mobile communication system, comprising the steps of:

providing the serving support node within a radio network connected to the UE and a gateway node for connecting the radio network to a home server in an external network;

acquiring from the external network the address of a home server that provides a service requested by the UE; and

storing the home server address, clearing charging information collected with respect to signaling generated prior to the allocation of the home server address, and re-collecting charging information about the service that the UE receives.

9. The method of claim 8 , wherein the acquiring step comprises the step of receiving an update message from the gateway node and acquiring the home server address included in an end user address (EUA) of the message.

10. The method of claim 8 , further comprising the step of transmitting the charging information re-collected by the serving support node to a billing server.

11. A system for accurately charging a user equipment (UE) in a mobile communication, comprising:

a Gateway GPRS Support Node (GGSN) for acquiring from an external network the address of a home server that provides a service requested by the UE; and

a Serving GPRS Support Node (SGSN) for storing the home server address, clearing charging information collected with respect to signaling generated prior to the allocation of the home server address, and re-collecting charging information about the service that the UE receives.

12. The system of claim 11 , wherein the GGSN receives an update message from the gateway node and acquires the home server address included in an end user address (EUA) of the message.

13. The system of claim 11 , wherein the GGSN and the SGSN transmit the charging information re-collected by the serving support node to a billing server.