Patent ID: 8260290

Claim:
A system for enabling a User Equipment (UE) to roam to a visited IP Multimedia Subsystem (IMS)-based network from a home network that does not have an IMS infrastructure, said system comprising: the UE for sending an access request to the IMS-based network, the access request being received by an Intelligent Roaming Application Server (I-RAS) in the IMS-based network; a connection between the I-RAS and the UE and between the I-RAS and the visited network, said I-RAS comprising: a storage means for storing temporary SIP URIs for use, in the visited IMS-based network, as temporary identifiers for visiting UEs; a receiving means for receiving a first registration request message originated by the UE, the first registration request message including a pre-defined SIP URI, for identifying the UE as visiting from a home network without an IMS infrastructure; sending means for sending a rejection of the first registration request message to the UE, the rejection including a temporary SIP URI; a registration assisting means for receiving a second registration request message from the UE, the second registration request including the temporary SIP URI as a temporary identifier to the UE for use while roaming in the visited network; and means for acting as a pseudo MSC/VLR towards the home network.