Analysis of IP-based Real-time Multimedia Group Communication in Heterogenous Wireless Networks

Multi-media group communication services are a new kind of community-driven services. One key concern is that access link qualities of different group members may vary significantly especially in case group members are connected via heterogenous wireless networks. As a consequence, the efficiency of a group communication is negatively impacted. In this paper we provide a simulation analysis on how the throughput of a peer-to-peer group communication can be reduced in case only a few members of a group are effected by a link quality degradation. We first classify group communication systems regarding their overall architecture and their floor control mechanisms. Afterwards a dedicated communication protocol (the Push-to-X protocol) - developed to efficiently support group communication on embedded system platforms - is introduced. After presenting the simulation environment, we present a basic group communication traffic model derived from empirical observations. Finally simulation results are discussed, showing a throughput reduction of up to 50% in case only one participant of a group communication is affected by an additional link delay.