SummaryIn 2022, the idea of the cosmic time synchronizer (CTS) was proposed for a precise wireless synchronization of local clocks (<100 ns). Because CTS does not require critical timing information traffic among CTS sensors, the technique can be considered robust against jamming and spoofing. In this work, a small-scale CTS sensor network has been developed and tested for the first time. Good time synchronization performances were obtained for a short-haul configuration (30–35 ns (SD, 1 σ), over 50–60 m). Based on the results of this work, CTS could be potentially conceived as a ‘self-adjusting’ system, offering high level continuous (perpetual) performances, to be considered either as a backup chain for GPS disciplined oscillators (GPS DO), a standalone standard for frequency and time interval measurements, or as a tool for the dissemination of reference time scales to final users, with improved characteristics in terms of robustness and reliability.