Scheduling with Time Aware Shaping in Integrated Ethernet and Wi-Fi Networks

Communication technologies play a significant role in systems engineering. The proliferation of connected embedded systems has resulted in Internet of Things applications. Many of these systems are safety or mission critical. For example, in smart manufacturing or health, reliability and low latency are significantly important. A deterministic communication system with real-time capability is essential for ensuring safety in those circumstances. Patient monitoring and remote surgery are two such examples. The maximum permitted delay for video in remote surgery is 200 ms and the minimum allowed latency for tactile feedback is 10 ms. The prior efforts of VLAN tagging over Ethernet are insufficient to ensure determinism and reliability. The upcoming IEEE Time-Sensitive Networking (TSN) standards have enabled determinism by regulating latency, jitter, and packet loss across different types of flows. However, currently, it is only widely available on Ethernet. The paper explores a scheduling approach for an integrated Ethernet and WiFi scenario dealing with mixed-priority traffic that leads to minimal violations of the end-to-end delay requirement. With WiFi TSN bridges and access points equipped with Time Aware Shapers, the proposed scheduling strategy is able to offer determinism while satisfying the requirements of a specific class of IoT applications.