Hardware-based precise time synchronization on Gb/s Ethernet

The accuracy and precision of time synchronization in Ethernet must be enhanced since Ethernet is becoming a critical component of telecommunication networks. This paper investigates a precise time synchronization technique that supports Gb/s Ethernet. To obtain accurate time synchronization, delay variation in message transfer and processing must be minimized. For this purpose, the paper first describes an implementation of preemptive priority queuing, which decreases the message delay variation of Ethernet. The paper then proposes a time synchronization method that is performed in the lower protocol layer and then describes its implementation on FPGA-based hardware. The proposed method achieves superior time accuracy and precision through the low message transfer/processing delay variation provided by preemptive priority, lower layer execution, and hardware implementation. The effectiveness of the method is confirmed through experiments.