Patent ID: 7965704
Filing Date: 2011-06-21
Classification: H04L,H04W

Abstract:
1. A method for processing a call request including a request for a real-time service received from an Internet protocol Multimedia Subsystem (IMS) terminal capable only of an IMS session, the method comprising the steps of: receiving, by a Combined Circuit Switched (CS) call and IMS session (CSI) terminal, an INVITE message including call requests for a real-time service and a non-real time service, from the IMS terminal through an Application Server (AS) of an IMS domain; creating, by the CSI terminal, a CSI indicator indicating that a CS call is used for the real-time service; deactivating, by the CSI terminal, a real-time service-related part of Session Description Protocol (SDP) parameters set in an IMS session response message; sending, by the CSI terminal, the IMS session response message including the CSI indicator to the AS; sending, by the CSI terminal, a CS call request for the real-time service to the AS; receiving, by the AS, the IMS session response from the CSI terminal; if the AS receives the CS call request for the real-time service from the CSI terminal over a CS domain, generating, by the AS, a message by associating the IMS session response message with the CS call request; and sending, by the AS, the generated message, as a response to the call requests from the IMS terminal, to the IMS terminal, wherein the CS call request message includes a pseudo number extracted from the INVITE message, the pseudo number being created by the AS, to enable the AS to recognize that the CS call request message is related to the INVITE message.