UNIFIED IMS SUPPLEMENTARY SERVICES SIGNALING ACROSS CIRCUIT AND PACKET DOMAINS

摘要

The present invention provides a method for signaling between an IP Multimedia Subsystem (IMS) and a multi-mode terminal using concise primitives to support the use of IMS-based services while the multi-mode terminal is attached to either the packet switched (PS) domain or to the circuit switched (CS) domain, or moves between these domains. The present invention enables the maintenance of services state in only the IMS and in the multi-mode terminal, thus avoiding the creation or transfer of services state information as the multi-mode terminal moves between the PS and CS domains.