A fine-grained controlled set-up to execute time synchronization protocol tests in a distributed environment

Time synchronization protocols assume a primary role in IoT era. Their design, implementation and test often follow separate paths and they are not ensured with the same level of accuracy. Simulation validation exhibits unpredictable gap with real performance levels. According to these statements and in order to answer to the proposed open issues, the paper present a fine-grained controlled environment to perform custom validation test of time synchronization algorithms. The set-up is built by adopting widely known Raspberry development boards, exploiting the ad-hoc fiber optic links provided by Unicas-Net, taking advantage of NetEm built-in emulator in Raspbian Operating Systems, and finally developing a tailored user-friendly software to adequately control network link quality. Accordingly, synchronizing nodes can connect to one of the open points (provided by Raspberry devices) of the network ring and run their algorithms with other nodes that access to the set-up at 50 km distance. Finally, time synchronization performance can easily be assessed by exploiting GPS time provided by the GPS receiver and antenna, which complete each board equipment. First functionality tests are also reported in the paper.