An efficient synchronization mechanism dynamically adapting to the network state for networked virtual environments

Abstract

One of key issues in multi-user interactive applications is to provide a consistent, shared view among participants while maintaining interactive performance. The buffered synchronization mechanism can support a consistent view by holding events in buffer until a fixed amount of time called payout delay expires and executing them at the same time at all participants. However, if events get lost or delayed, consistency may not be kept among participants, which causes an overhead to recover the lost information. On the other hand, the execution of events should be delayed more than it could have happened when the events arrive earlier than the play delay. In this thesis, we propose an efficient event synchronization scheme adapting dynamically to a network state that ensures a consistent view among participants while maintaining interactive performance. Each participant determines the payout delay dynamically based on the estimated network state. If a network state is lightly loaded, the payout delay decreases. It increases in case of a heavily loaded network state. The simulation results show that the proposed scheme provides more consistent view among the participants than the static scheme when the heavily loaded network state continuous and improve the interactive performance when network state is lightly loaded.