**6. Conclusions**

This study proposed a topology control method for energy-efficient UAV networks. Our system acts as an intermediate layer between the network and data link layer, so it is tolerant of any other network environments. By numerical evaluations, we showed that our space partition method highly reduces the power consumption of the end-to-end connections, while maintaining the node degree and the hop count in a proper amount. We hope that our approach based on the space partition inspires UAV network research domains.

**Author Contributions:** Conceptualization, H.K.; methodology, S.P., H.T.K., and H.K.; software, S.P., H.T.K., and H.K.; validation, S.P., H.T.K., and H.K.; formal analysis, S.P., H.T.K., and H.K.; investigation, S.P., H.T.K., and H.K; resources, S.P. and H.T.K.; data curation, S.P. and H.T.K.; writing–draft preparation, S.P. and H.T.K.; writing–review and editing, S.P., H.T.K., and H.K.; visualization, S.P. and H.T.K; supervision, H.K.; project administration, H.K.; funding acquisition, H.K.

**Funding:** The authors gratefully acknowledge the support from Nano UAV Intelligence Systems Research Laboratory at Kwangwoon University, originally funded by Defense Acquisition Program Administration (DAPA) and Agency for Defense Development (ADD).

**Conflicts of Interest:** The authors declare no conflict of interest. The founding sponsors had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, or in the decision to publish the result.
