Event based charging in a communications system

A network subsystem for implementing event based charging in a communications system by filtering service flows between end user equipments and application servers, the network subsystem having a computer-readable storage medium encoded with software that when executed cause the network subsystem to:

• identify an instance of service flow between an end user equipment and a particular application server;
• send a first message containing information identifying a set of events to report, and
• receive a second message responsive to occurrence of an event that is one of the set of events at the particular application server for the instance of service flow, the second message containing an event result that is correlated with the instance of service flow, and the event result containing information about occurrence of the event.

A computer server associated with an event owner of an application server for which event based charging is implemented for service flows between end user equipments and the application server by a network subsystem filtering the service flows for charging purposes, wherein the computer server associated with the event owner is configured to:

• receive a first message from the network subsystem requesting notification of a set of events associated with an instance of service flow, and
• in response to occurrence of an event that is one of the set of events at the application server, send a message to the network subsystem containing an event result containing information about the occurrence of the event.

A method of event based charging in a communications system wherein service flows between end user equipments and application servers are filtered for charging purposes, the method comprising:

• a network subsystem identifying an instance of service flow between an end user equipment and a particular application server;
• the network subsystem sending a first message containing information identifying a set of events to report;
• the network subsystem receiving a second message containing an event result responsive to occurrence of an event of the particular application server that is one of the set of events and that is associated with the instance of service flow, wherein the event result contains information regarding occurrence of the event.