Patent ID: 9191910
Filing Date: 2015-11-17
Classification: H04L,H04W

Abstract:
1. A method performed by a Serving Call Session Control Function (S-CSCF) in an Internet Protocol Multimedia Subsystem (IMS) network, comprising: receiving, from a User Equipment (UE), a registration request message that carries an IMS Private User Identity (IMPI) and IMS Public User Identity (IMPU) pair; in response to receiving the registration request message, determining: a) a lack of registration data corresponding to the IMPI and IMPU pair in the S-CSCF; and b) that the registration request message includes a reg-id parameter, which indicates that the registration request message relates to a multi-registration associated with the IMPI and IMPU pair; after determining (a) and (b), sending a Server Assignment Request (SAR) message to a Home Subscriber Server (HSS) in the IMS network, wherein the SAR message carries the IMPI and IMPU pair, a parameter for identifying that the SAR message relates to an initial registration of a user, and a multiple registration indication which indicates that the SAR message relates to the multi-registration associated with the IMPI and IMPU pair; and receiving a Server Assignment Answer (SAA) message carrying registration backup data corresponding to the IMPI and IMPU pair from the HSS.