Flexible and seamless service migration for real-time communication with ubiquitous and heterogeneous networked resources

We present a service initiation and migration system for real-time communication services in a ubiquitous networking environment. The key concepts are: (1) the isolation of a few functions as common components with SIP protocol from realtime applications; (2) the incorporation of service migration into service initiation so that users can change resources at any time during communication; and (3) service negotiation which enables all user requests and situations to he reflected in the service. Therefore, users can enjoy real-time communication even when they face resource heterogeneity and changeable situations in the ubiquitous networking environment. The implementation of this system and the experimental results are also described, which demonstrate that users can switch devices and applications seamlessly without terminating the session.