Dynamic Network Topology Configuration and Resource Switching for Real-Time Group Communication in a Ubiquitous Networking Environment

In a ubiquitous networking environment, each user has diverse resources in terms of nodes, links and applications, so we proposed a resource switching mechanism to mediate the diversity between a pair of users. However, in group communication, the network topology of the group should also be taken into account. This is because a conventional approach using a server centric topology has a scalability problem on the server. Another mechanism using a peer-topeer topology requires higher computation power and link bandwidth to the nodes for exchanging media data. Moreover, the available resources vary according to user context, and this affects the decision as to which topology to apply. In this paper, we propose a method to adapt our resource switching mechanism to real-time group communication. In order to avoid load concentration on the server and accommodate heterogeneous nodes, we introduce a novel network topology and a means of changing the network topology configurations dynamically. The experimental results using a prototype show that our system can reduce the load on the server and data delay.