Concealing network delays in delay-sensitive online interactive games based on just-noticeable differences

Online delay-sensitive games with fast interactive actions, like fighting games (FTG) and sports games, require the synchronization of coupled multi-player actions. With network impairments, action commands from other players can be delayed or lost, leading to compromised real-time perception of these games. In contrast to slower strategy games, online fighting and sports games studied in this paper require realtime judgment and instant feedbacks. Traditional methods for optimizing the delay effects of these games are focused on quantifying round-trip delays, without examining the perceptual effects of players. In this paper, we develop a new criterion using just-noticeable differences (JND) for optimizing the duration of actions and responses. Our approach aims to reduce the probability of players perceiving the delay effects, when compared to a reference game with zero network delay. Using statistics collected in offline subjective tests, the timing of actions is modified at run time. Experimental results show significant reduction of players´ awareness of network delays using our approach when compared to existing delay-concealment schemes.