OpenSync: Enabling Software-Defined Clock Synchronization in Deterministic Ethernet

Deterministic Ethernet (DetEth) is widely used in real-time distributed systems, such as avionics and in-vehicle control. Clock synchronization protocols (CSPs) establish global time, which is a critical foundation for deterministic communication in DetEth. However, existing protocols often lack flexibility, making customization and adaptation to specific scenarios difficult and time consuming. We propose OpenSync, which is a software-defined clock synchronization architecture that decouples the synchronization control plane from the data plane. OpenSync includes a programmable time data injector and a fine-grained calibrated timer in the data plane, enabling easy implementation with standard DetEth hardware and support for various CSPs. The control plane provides a synchronization library to configure local clocks and retrieve accurate time data for different methods. To validate OpenSync’s generality and efficiency, we develop an FPGA-based prototype and implement three CSPs through software programming. A fully functional testbed demonstrates that these CSPs meet the accuracy and protocol consistency requirements of their respective application scenarios.