Offline charging for sessions over a 3GPP network and a WLAN access network
View Patent ↗Communication networks and methods are disclosed for providing offline charging in a 3GPP network for sessions over a wireless local area network (WLAN) access network. A AAA server in the 3GPP network provides offline charging messages for a session to an offline charging system. If a data flow is established during the session, such as streaming video, then a packet data network gateway provides offline charging messages for the data flow to the offline charging system. The AAA server and the packet data network gateway share charging identifiers so that one or both are able to include the charging identifier for the session and the charging identifier for the data flow in an offline charging message. This allows the offline charging system to effectively correlate CDRs for the session with CDRs for the data flow occurring during the session.
1. A system comprising:
a charging system operable to receive a first accounting request for a session from a first network element that manages a session for a communication device, and to receive a second accounting request for a data flow occurring during the session from a second network element that manages the data flow during the session, wherein at least one of the accounting requests includes a session charging identifier for the session and a data flow charging identifier for the data flow;
the charging system is further operable to generate a first Charging Data Record (CDR) for the session based on the first accounting request, to generate a second CDR for the data flow based on the second accounting request, and to insert the session charging identifier and the data flow charging identifier in at least one of the CDRs;
the charging system is further operable to correlate the first and second CDRs based on the session charging identifier and the data flow charging identifier inserted in the at least one of the CDRs to generate a consolidated CDR, and to transmit the consolidated CDR to a billing system.
2. The system of claim 1 wherein:
the charging system is further operable to receive a third accounting request for another data flow occurring during the session from the second network element, wherein the third accounting request includes the session charging identifier for the session and a data flow charging identifier for the other data flow;
the charging system is further operable to generate a third CDR for the other data flow based on the third accounting request, and to insert the session charging identifier and the data flow charging identifier for the other data flow in the third CDR; and
the charging system is further operable to correlate the first, second, and third CDRs based on the session charging identifier and the data flow charging identifiers to generate the consolidated CDR.
3. The system of claim 1 wherein:
the first network element comprises an Authentication, Authorization, and Accounting (AAA) server.
4. The system of claim 1 wherein:
the second network element comprises a packet data network gateway.
5. The system of claim 1 wherein:
the charging system is coupled to at least one of the network elements over an enhanced Diameter interface, wherein the enhanced Diameter interface includes:
an Attribute Value Pair (AVP) assigned to the session charging identifier; and
an AVP assigned to the data flow charging identifier.
6. The system of claim 5 wherein the enhanced Diameter interface further includes:
an AVP assigned to a start timestamp for the data flow; and
an AVP assigned to a stop timestamp for the data flow.
7. The system of claim 5 wherein the enhanced Diameter interface further includes:
an AVP assigned to a data flow description.
8. The system of claim 5 wherein the enhanced Diameter interface further includes:
an AVP assigned to a data flow cause code.