  Consumer Virtual Reality (VR) has been widely used in various application
areas, such as entertainment and medicine. In spite of the superb immersion
experience, to enable high-quality VR on untethered mobile devices remains an
extremely challenging task. The high bandwidth demands of VR streaming
generally overburden a conventional wireless connection, which affects the user
experience and in turn limits the usability of VR in practice. In this paper,
we propose FoVR, attention-based hierarchical VR streaming through
bandwidth-limited wireless networks. The design of FoVR stems from the insight
that human's vision is hierarchical, so that different areas in the field of
view (FoV) can be served with VR content of different qualities. By exploiting
the gaze tracking capacity of the VR devices, FoVR is able to accurately
predict the user's attention so that the streaming of hierarchical VR can be
appropriately scheduled. In this way, FoVR significantly reduces the bandwidth
cost and computing cost while keeping high quality of user experience. We
implement FoVR on a commercial VR device and evaluate its performance in
various scenarios. The experiment results show that FoVR reduces the bandwidth
cost by 88.9% and 76.2%, respectively compared to the original VR streaming and
the state-of-the-art approach.
