# Closing Connectivity Gap: An Overview of Mobile Coverage Solutions for Not-Spots in Rural Zones
## 4 Discussion
### Future Research Opportunities  
In the prior section, we have introduced three achievable solutions to strive against the countryside's not-spots. There remain shortcomings stuck in the fully fledged method of granting connectivity to pursue endurance in the deployed system. UAV-based networks seem to be an attractive option due to their commercial affordability, as we pointed out in Section 3.1. However, for now, both UAS and Altitude Platforms have factors opposed to large scale use, such as payload capability--to shoulder the network equipment--and insufficient MNO interest, behind higher returning investment rates. Consequently, three categories claim further analysis in the case of deploying aerial networks. Firstly, A2G channel modeling needs to be supplied by a realistic propagation model, since most of them are still limited to a single device or particular environments. Moreover, there is a considerable need to characterize the by-mobility Doppler effect, in addition to the channel's captured time variation addressing more precision and accuracy. Fueled by the efforts to sketch the A2G channel--as it was analyzed in Section --the need to address research in this field has arisen and becomes more decisive as consumer demands grow. Secondly, aerial platforms lacking an optimal 3D placement are of concern. A match-less location bestows the coexistence with the terrestrial cellular networks and avoids mutual interference with GBS. In the case of UAS, an optimal arrangement of UAV-BS can yield a minimum downlink transmission latency, setting up previously the drone-BS location and transmission bandwidth [52]. This approach can reduce the total flight time while also enhancing energy consumption. With respect to concern on energy issues of SCP--which may be the foremost challenge to assure connectivity's significant periods--the utilization of peer-to-peer energy sharing has been investigated since energy is a limited resource in mobile networks because they are jammed in non-renewable sources such as batteries. According to the application, an attractive solution to outpace the excessive consumption of energy, mainly focused on re \begin{table}
\begin{tabular}{l l l} \hline \hline
**Solution (Section)** & **Advantages** & **Disadvantages** \\ \hline \multirow{4}{*}{UAVs [Section 3.1]} & • Easily deployable and portable. &  • Static-channel-modeling intermittent connectivity. \\  & • Reliable infrastructure to enhance coverage. &  • Energy constraints and limited effective payload. \\  & • New security standards by new routing protocols. &  • Uncertainty on legislation. \\  & • Compatible with others as terrestrial and aerial &  • Inefficient obstacle awareness rollout. \\  & • network’s platforms. &  • From protocol standardization. \\ \hline \multirow{4}{*}{HAPs [Section 3.2]} & • Commit to cover immensely inaccessible areas. &  • From protocol standardization. \\  & • Allows adaptable resource allocation. &  • From design of traffic aggregation. \\  & • Low roll-out costs. &  • From design of interference mitigation in shared \\  & • Guarantee connectivity by a single platform. &  • From raters of interference mitigation in shared \\  & • Agile deployment. &  • From spectrum. \\  & • Payload upgrading. &  • From insufficient coverage time assessment. \\ \hline \multirow{4}{*}{LEOs [Section 3.2]} & • Enable higher QoS than terrestrial. &  • From design of deployment and maintenance. \\  & • Reach a latency issue standard. &  • From design of traffic aggregation. \\ \cline{1-1}  & • Add significant bit rate capacity. &  • From design of traffic aggregation. \\ \cline{1-1}  & • Provide high capacity backhaul. &  • From design of traffic aggregation. \\ \hline \hline \end{tabular}
\end{table} 
Table 7: Comparison among the analyzed solutions for rural coverage. newable sources, appears to be a significant research field for guaranteeing communication availability [116].