Megabits Down to Kilobits: Memory-Efficient Time-Aware Shaping for TSN

Time-Sensitive Networking (TSN) provides bounded latency and low jitter for cyber-physical systems, such as industrial control. As a key component of TSN, the Time-Aware Shaper (TAS) applies gate control rules to control the transmission time of frames in critical flows. TAS stores the gate control rules for each frame in the gate control table. However, in typical industrial setups, the memory usage of the table could reach over tens of megabits and even exceed the total memory capacity of TSN switches.To address this issue, we propose a memory-efficient TAS design named METAS. It transitions from a per-frame to a per-flow approach. METAS stores one persistent rule for a flow and dynamically generates a temporary rule for a frame only when the frame arrives. We prototyped METAS on an FPGA, and experimental results show that METAS reduces memory usage from 14.34 Mbits to 288 Kbits when supporting 1,024 flows, using just 1.56% of the FPGA’s logic resources while maintaining microsecondlevel latency and nanosecond-level jitter for critical flows.