  Time-Sensitive Networking (TSN) is an emerging real-time Ethernet technology
that provides deterministic communication for time-critical traffic. At its
core, TSN relies on Time-Aware Shaper (TAS) for pre-allocating frames in
specific time intervals and Per-Stream Filtering and Policing (PSFP) for
mitigating the fatal disturbance of unavoidable frame drift. However, as first
identified in this work, PSFP incurs heavy memory consumption during policing,
hindering normal switching functionalities.
  This work proposes a lightweight policing design called FooDog, which could
facilitate sub-microsecond jitter with ultra-low memory consumption. FooDog
employs a period-wise and stream-wise structure to realize the memory-efficient
PSFP without loss of determinism. Results using commercial FPGAs in typical
aerospace scenarios show that FooDog could keep end-to-end time-sensitive
traffic jitter <150 nanoseconds in the presence of abnormal traffic, comparable
to typical TSN performance without anomalies. Meanwhile, it consumes merely
hundreds of kilobits of memory, reducing >90% of on-chip memory overheads than
unoptimized PSFP design.
