Performance Evaluation of IMS Session Continuity Signaling with Heterogeneous Access

The IP Multimedia Subsystem (IMS) Service Continuity is a recent effort by 3GPP towards achieving an enhanced mobility experience for IMS subscribers. It provides mechanisms to manage continuity of IMS services, particularly the seamless transfer of multimedia sessions across different access networks, different domains, and the mobility of ongoing sessions across devices of the same user. Functionally, it is mobility management at the IMS services and applications layer when terminal and session mobility events are visible to the IMS. Although mobility management is a thoroughly explored and extensively documented area of research, the approach has not always been service-oriented, whereby users are able to actually subscribe to the provisioning of this functionality. This is the new context introduced by IMS service continuity. There are, however, few reports on actual implementation and specific practical evaluations of IMS service continuity. In this work, we perform a testbed implementation and evaluation of IMS service continuity. Particularly, we investigate the signaling aspects of the service in a heterogeneous wireless networks environment. We develop a prototype service continuity application server, and use it with the UCT IMS Client and the FOKUS Open IMS Core to determine the effect of service continuity signaling on end user experience.