# IoT and UAV Integration in 5G Hybrid Terrestrial-Satellite Networks
## 5 IoT, UAVs, and Satellites in the Emerging 5G Technology
### IoT, UAV/Satellite, and 5G Integration
Having a satellite-based flying 5G-gNB is a very interesting scientific and technical challenge involving problems and implementation issues to be tackled in both software and hardware. For the same motivations, it is not of immediate application. Satellites acting as RNs are the most realistic option for the near future. Satellites already deployed and implementing other \"classical\" satellite communication protocols (e.g., DVBS2) can be exploited for this purpose. Satellites equipped with 5G-gNB functionality need to be designed and launched for this purpose, which could take more time than the few years forecast for the 5G terrestrial network activation. Figures 5-7 picture the network architecture considering the IoT devices as objects equipped with all 5G components to let them directly get access to a 5G cell, i.e., IoT devices are 5G-UE. This solution is not compliant with all the currently available commercial IoT solutions and would impose a unique standard for IoT communications in 5G. The presence of a unique standard technology avoiding compatibility issues among different solutions would be a great advantage. Anyway, industries that have already gained access to the market and sold their products will not easily give up their market share. Moving 5G-UE to the IoT devices allows both UAVs and satellites to act as simple RNs, as in Figure 5, or to host 5G-gNBs on the satellite, as shown in Figure 6, implying the already mentioned increased burden in the hardware complexity and higher required resources, which need to be properly managed. The case of 5G-gNB on the UAV is shown in Figure 7. It introduces additional hardware/software complexity on-board the UAVs. Even if moving 5G-UE within IoT devices is a fascinating and scientifically stimulating solution, as the choice to have 5G-gNB on-board a satellite or a UAV was already discussed, from the practical viewpoint, these actions cannot be immediately implemented. Figure 4: 5G-UE on the UAV and 5G-gNB on the satellite. Figure 3: 5G-UE on the UAV, 5G-gNB on the ground close to the UAV, and the satellite as the backhaul between 5G-gNB and 5G-CN. Figure 2: 5G-UE on the UAV, satellite as RN, and terrestrial 5G-gNB. Table 3 summarizes the pros and cons of each identified solution. The solutions we see as the possible first step of the integration between non-terrestrial and terrestrial networks within the 5G framework are the ones shown in Figures 2 and 3. Figure 5: 5G-UE in the IoT device, UAV and satellite as RNs, and terrestrial 5G-gNB. Figure 6: 5G-UE in the IoT device and 5G-gNB on the satellite. Figure 7: 5G-UE in the IoT device and 5G-gNB on the UAV. \begin{table}
\begin{tabular}{p{42.7 pt} p{42.7 pt} p{42.7 pt} p{42.7 pt} p{42.7 pt} p{42.7 pt} p{42.7 pt}} \hline \hline
**Solution** & **IoT Device** & **UAV** & **Satellite** & **Satellite** & **Satellite** & **Pros** & **Cons** \\ \hline  & & & & & & simpler IoT devices and simpler bent-pipe 5G-agnostic satellites as the ones already available and & IoT devices not able to get direct access to the 5G network; more \\ Figure 2 & not 5G oriented & 5G-UE & RN & RN (or 5G-sNB) & RN & the terrestrial segment’s nodes, which do not have strict resource constraints. & complexity UAVs with high energy consumption due to protocol conversion. \\ \hline  & & & & & & simpler IoT devices and simpler bent-pipe 5G-agnostic satellites as the ones already available and & IoT devices not able to get direct access to the 5G network; more \\ Figure 3 & not 5G oriented & 5G-UE & RN & RN & RN & complex UAVs with high energy consumption due to protocol conversion. \\ \hline  & & & & & & \\  & & & & & & \\  & & & & & & \\  & & & & & & \\  & & & & & & \\  & & & & & & & \\ \hline  & & & & & & & \\ \end{tabular}
\end{table} 
Table 3: Pros and cons of the identified integrated solutions. \begin{table}
\begin{tabular}{p{56.9 pt} p{56.9 pt} p{56.9 pt} p{56.9 pt} p{56.9 pt} p{56.9 pt} p{56.9 pt}} \hline \hline
**Solution** & **IoT Device** & **UAV** & **Role of Satellite** & **Sat.