  Millimeter-wave(mmWave) technology has emerged as a promising enabler for
unleashing the full potential of 360-degree virtual reality (VR). However, the
explosive growth of VR services, coupled with the reliability issues of mmWave
communications, poses enormous challenges in terms of wireless resource and
quality-of-service (QoS) provisioning for mmWave-enabled 360-degree VR. In this
paper, we propose an innovative 360-degree VR streaming architecture that
addresses three under-exploited issues: overlapping field-of-views (FoVs),
statistical QoS provisioning (SQP), and loss-tolerant active data discarding.
Specifically, an overlapping FoV-based optimal joint unicast and multicast
(JUM) task assignment scheme is designed to implement the non-redundant task
assignments, thereby conserving wireless resources remarkably. Furthermore,
leveraging stochastic network calculus, we develop a comprehensive SQP
theoretical framework that encompasses two SQP schemes from delay and rate
perspectives. Additionally, a corresponding optimal adaptive joint time-slot
allocation and active-discarding (ADAPT-JTAAT) transmission scheme is proposed
to minimize resource consumption while guaranteeing diverse statistical QoS
requirements under loss-intolerant and loss-tolerant scenarios from delay and
rate perspectives, respectively. Extensive simulations demonstrate the
effectiveness of the designed overlapping FoV-based JUM optimal task assignment
scheme. Comparisons with six baseline schemes validate that the proposed
optimal ADAPTJTAAT transmission scheme can achieve superior SQP performance in
resource utilization, flexible rate control, and robust queue behaviors.
