# An Experimental Tethered UAV-Based Communication System with Continuous Power Supply
## 5 Conclusions  
This paper presents a conceptual proposal for a tethered UAV-based communication system with continuous power supply, along with a detailed implementation of a proof-of-concept UAV-enabled communication system utilizing a Raspberry Pi 4B platform and a ground station. The prototype's implementation was based on a thorough theoretical analysis of various sources related to communication technologies for UAVs and the power supply options used in these devices. Based on this analysis, the electrical requirements for designing and implementing the power supply network were determined, which was based on a tethered system. The results validate the viability of the proposed solution. Regarding costs, the budget required for this prototype was exactly USD 777, a considerably affordable investment compared to commercial T-UAV systems, such as those from Lifeline, which are priced at USD 6,500. The cost difference of our solution highlights the proposed prototype's economic viability, offering the possibility of testing, which favors its implementation in research scenarios or with limited financial resources. With the T-UAV system, the flight time becomes indefinite thanks to the continuous power supply from the ground. In the tests performed with the prototype developed in this project, it was determined that the UAV requires a voltage of 16 V and a current of 20 A, values that served as the basis for designing the power supply system. Using a 1500 mAh battery as the power source, a theoretical flight time of approximately 4.5 min was estimated. However, the cable-powered system demonstrated its effectiveness by extending the flight time to 7 min during testing, thus validating its ability to significantly increase the UAV's autonomy compared to using only a battery. The energy performance of the UAV, with a total weight of 1940.8 g, was analyzed, noting that as the altitude changed, the electrical requirements varied significantly. As the height increased, so did the energy demand, highlighting that the current was the variable with the most significant fluctuation. This behavior indicates that at higher altitudes, the UAV faces more significant difficulties in maintaining its stability, which translates into a proportional increase in its energy consumption (mainly an increase in electric current). Future work will include integrating the Raspberry Pi power supply into the system's overall power network. This integration would address one of the project's main limitations, as currently, only the UAV is powered from the ground. Additionally, to enhance the system's operational continuity, a backup battery is planned for the UAV to ensure its service in the event of power supply interruptions or potential damage to the power cable. An alternative development approach is to make the entire communications system prototype entirely battery-powered, which implies the use of accordingly sized battery units in the GCS, offering portability and autonomy to the UAV-enabled communications system prototype. Regarding the power cable length, future work will also be devoted to designing a cable-pulling system that can reach altitudes exceeding 10 m and be applied in realistic post-disaster or energy scenarios. Furthermore, to enhance the environmental robustness of the system, future work will focus on testing and adapting the platform to operate effectively in windy and rainy conditions. A comprehensive evaluation will be conducted under varying wind speeds. Additionally, waterproofing measures will be incorporated into the UAV design to enable operation during light to moderate rainfall, ensuring the system's resilience and reliability in more realistic deployment scenarios. Conceptualization, V.R., C.T., D.R., J.C.-R., C.E.A., P.P. and X.H. ; methodology, V.R., C.T., D.R., J.C.-R., C.E.A. and P.P. ; software, V.R., C.T., D.R. and J.C.-R.; validation, V.R., C.T., D.R., J.C.-R., C.E.A., P.P. and X.H. ; formal analysis, V.R., C.T., D.R. and J.C.-R.; investigation, V.R., C.T., D.R., J.C.-R., C.E.A., P.P. and X.H.