**6. Conclusions**

This paper introduced one of the first experiment on the joint use of a 5G and VLC network to provide information to cars. Data from road sensors has been collected by a 5G network and then sent to a VLC network for diffusion to cars through traffic-lights. In addition, data from on-demand emergency alarm has been implemented. The experiment aimed to measure the overall latency. The results showed that a total latency of about 12 ms can be reached. In particular, the most frequent latency for the 5G link was about 9.5 ms, while for the VLC link, it was about 2.5 ms. The main contribution is related to the 5G network part, that should be optimized, especially with the deployment of the SA 5G architecture.

**Author Contributions:** Conceptualization, D.M. and L.M.; software, S.C., T.N. and M.S.; validation, T.P. and J.C.; data curation, S.C. and F.N.; writing—original draft preparation, D.M. and L.M.; writing—review and editing, T.P. and R.F.; supervision, R.F., J.C. and L.M. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research was carried out as part of the "5G City" project, supported by the Italian Ministry of Economic Development.

**Acknowledgments:** The authors would like to thank the Associate Editor and the Assistant Editor for managing the overall publication process as well as the anonymous reviewers for their useful suggestions to improve the quality of the manuscript.

**Conflicts of Interest:** The authors declare no conflict of interest.
