Harmonized mobility management in IMS networks based on the SSON concept

As IP communications become abundant in the mobile world, the beyond 3G network concept tends to find anchorage in IMS technology. IMS shows potential for supporting rich-content applications and mixed user communication scenarios over mobile, wireless, and fixed access interfaces. IMS important advancement is the capacity for "liberalized" communications, where service provisioning is decoupled from the network infrastructure, thus making possible deployment across multi-operator networks. This article introduces such a federation mechanism for harmonized user mobility management, based on the Single Sign ON (SSON) concept of network registration. We demonstrate how the SSON functionality can be incorporated in the IMS architecture and exploited in achieving seamless user handover/ roaming and service continuity across multi-operator mixed-technology networks.