The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 04, 2012
Filed:
Nov. 24, 2008
Todd A. Pressley, Superior, CO (US);
Kevin Stiles, Allen, TX (US);
Serdar Sahin, Plano, TX (US);
Telefonaktiebolaget LM Ericsson (publ), Stockholm, SE;
Abstract
A system and method for enabling a UE to roam to a visited IMS-based network from a home network that does not have an IMS infrastructure. A visiting UE sends to an Intelligent Roaming Application Server (I-RAS) in the visited network, a first SIP Registration message that includes a SIP URI identifying the UE as a visitor from a home network that does not have an IMS infrastructure. The I-RAS rejects the registration, but includes a temporary Tel URI in the rejection message. The UE sends a second Registration message using the temporary Tel URI, which is forwarded to a Visited S-CSCF for authentication. The S-CSCF returns authentication vectors, which the UE uses to compute ciphering parameters and establish an IPSEC connection with a Visited P-CSCF. The UE then sends a third Registration message, which is accepted, and registration in the visited network is complete. The I-RAS acts as a pseudo Visited MSC/VLR and performs an update location procedure with the visiting UE's home network.