Patent ID: 8743868

Claim:
A method of control of IP Multimedia Subsystem (IMS) sessions and services, the method comprising: a User Equipment (UE) using Unstructured Supplementary Service Data (USSD) via a Circuit Switched (CS) network access so as to associate the UE with an IMS adapter (IA); providing an IA identifier to the UE; initiating at least one USSD message via a switching node in the CS network for control of a session or service in an IMS network; detecting the IA identifier in the at least one USSD message; determining an IA instance from the IA identifier; routing the at least one USSD message to the IA instance; the IA instance allocating a routing number to an IMS Centralized Service (ICS) client in the UE; returning the routing number to the ICS client in the UE; the ICS client using the routing number for setting up a user plane from the UE to the IA; the IMS network sending a Session Initiation Protocol (SIP) Invite message to the IA, which requests a Mobile Station Routing number (MSRN) from the switching node; the IA determining the switching node address by using a Short Message Service-Send Routing Information (SMS-SRI) message towards a Home Location Register (HLR); the IA sending a terminating session indication via the at least one USSD message to a USSD application in the switching node; the switching node sending a terminating USSD message or transaction to the ICS client in the UE; and the USSD application in the switching node allocating the MSRN and adding the MSRN to a USSD result received from the ISC client in the UE and returned to the IA.