IMS enhanced filter and action criteria

In current 3GPP specifications initial filter criteria (iFC) and also the Shared iFC (SiFC) optimization (optional in the specs) are defined as part of the user service profile; This is linked to the user in order to allow forwarding of the initial received request to the proper Application Server (AS) running the required service logic. That approach considers that all service logic is performed at the AS and then the only defined action for the iFC (when trigger conditions are met) is to forward the request to the AS. The specifications however allow for additional ldquocall control logicrdquo at the S-CSCF that is outside the scope of the iFC controls. This paper presents a solution consisting of extensions to the iFCs schema. This can be used as a way to enable such call control logic the S-CSCF. If SiFC are used, the only impacted network element (NE) would be the S-CSCF.