Patent ID: 9693373
Date: 2017-06-27
CPC Classifications: H04L,H04W

Claim:
1. A method of operating a communication system having multiple Internet Multimedia Subsystem (IMS) Session Control Servers and multiple IMS Transfer Control Servers that are individually associated, the method comprising: one of the IMS Session Control Servers receiving a media registration for a UE over a communication network; the one IMS Session Control Server establishing a media session for the UE over the communication network; an IMS Translation Server maintaining a data structure that individually associates the UE with the one IMS Session Control Server based on the registration and that individually associates the one IMS Session Control Server with one of the IMS Transfer Control Servers, wherein the IMS Translation Server does not comprise a Home Subscriber Server (HSS); the IMS Translation Server receiving a session transfer request for the one UE from another communication network indicating a general session transfer number for the multiple IMS Transfer Control Servers, processing the data structure to translate the general session transfer number for the multiple IMS Transfer Control Servers into an individual session transfer number for the one IMS Transfer Control Server, and responsively transferring the session transfer request for delivery to the one IMS Transfer Control Server; and the one IMS Transfer Control Server transferring the media session for the UE to the other communication network responsive to the session transfer request.