Impact of Delays on 360-degree Video Communications

Internet of Things (ToT) and Virtual/Augmented Reality (VR/AR) are shaping our future by merging the digital and the physical words. In this trend, 360-degree video which is a key component of VR/AR is becoming increasingly popular nowadays. For effective transmission of bandwidth-intensive 360-degree videos over the network, viewport-adaptive streaming has been introduced. In this paper, we study the impact of the response delay on viewport-adaptive streaming of 360-degree videos. Specifically, we focus on two key components of the response delay which are 1) adaptation interval and 2) client buffering delay. Experiment results show that viewport-adaptive streaming is only effective under short adaptation intervals and buffering delays. Under long response delay such as in HTTP Adaptive Streaming, it is found that viewport-adaptive methods are even worse than viewport-independent one.