Patent ID: 9148451
Filing Date: 2015-09-29
Classification: H04L

Abstract:
1. A method implemented by a terminal device connected to a switching server via an Internet Protocol Multimedia Subsystem (IMS) for being provided one or both of circuit-switched calls and services over a packet-switched session, wherein the switching server comprises an access call control entity configured to handle circuit-switched signaling messages for providing one or both of circuit-switched calls and services over circuit-switched connections to terminal devices connected to the switching server via one or more circuit-switched access systems, the method comprising: using circuit-switched signaling messages at a service-providing entity of the terminal device for one or both of said circuit-switched calls and services, wherein the circuit-switched signaling messages conform to a protocol for being provided said calls and services over a circuit-switched connection towards said access call control entity; interworking, at a first interworking entity comprised within the terminal device, between said circuit-switched signaling messages and signaling messages that conform to a protocol for packet-switched sessions via the IMS, inversely to a second interworking entity at the switching center; establishing a packet-switched session between the first interworking entity at the terminal device and the second interworking entity at the switching server; exchanging circuit-switched signaling messages between the terminal device and the access call control entity of the switching center over the established packet-switched session, via said first and second interworking entities.