Patent ID: 8521170
Filing Date: 2013-08-27
Classification: H04L,H04M,H04Q,H04W

Abstract:
1. A method, practiced by a Network Domain Selection (NeDS) network entity in an Internet Protocol (IP) multimedia subsystem (IMS), of routing an incoming call, comprising: receiving a message from a Home Subscriber Server (HSS), the message being a notification message generated to inform the NeDS network entity, wherein the message indicates that a User Equipment (UE) has attached to a network; starting a timer upon receipt of the message, the timer having a pre-determined expiry period, wherein the NeDS network entity determines that the UE supports a given IMS service if a third party registration message is received before the timer reaches its predetermined expiry period; and on receiving the incoming call, consulting a database to determine a terminating network, wherein the terminating network supports the given IMS service if the NeDS network entity has determined that the UE supports the given IMS service.