Abstract
Presence services collect noticeable attention as one of the major communicative applications in the ubiquitous netowork, where Internet access is available "anytime" and "anywhere". The authors have been developing FieldCast1, a combination of peer-to-peer presence service and Media Handover technology that supports seamless switching between different types of access networks. During the development and feasibility test of FieldCast1, we have found some points to be improved such as customizability of privacy control and performance factors of Media Handover functions. Thus we made a thorough review of our previous implementation and developed FieldCast2,based on the revised system architecture. In this paper, we introduce the improvements of the design of FieldCast2, with its system architecture, together with our evaluation of its improvements over the previous system architecture.