  Along with the rapid growth of Industrial Internet-of-Things (IIoT)
applications and their penetration into many industry sectors, real-time
wireless networks (RTWNs) have been playing a more critical role in providing
real-time, reliable and secure communication services for such applications. A
key challenge in RTWN management is how to ensure real-time Quality of Services
(QoS) especially in the presence of unexpected disturbances and lossy wireless
links. Most prior work takes centralized approaches for handling disturbances,
which are slow and subject to single-point failure, and do not scale. To
overcome these drawbacks, this paper presents a fully distributed packet
scheduling framework called FD-PaS. FD-PaS aims to provide guaranteed fast
response to unexpected disturbances while achieving minimum performance
degradation for meeting the timing and reliability requirements of all critical
tasks. To combat the scalability challenge, FD-PaS incorporates several key
advances in both algorithm design and data link layer protocol design to enable
individual nodes to make on-line decisions locally without any centralized
control. Our extensive simulation and testbed results have validated the
correctness of the FD-PaS design and demonstrated its effectiveness in
providing fast response for handling disturbances while ensuring the designated
QoS requirements.
