# Mobility Management of Unmanned Aerial Vehicles in Ultra-Dense Heterogeneous Networks
## 6 Proposed Solutions
### RSS-Based Algorithms  
RSS data is used in algorithm-based HO management systems. RSS-based computations are generally less complex, but they are also less precise. Calculations have the benefit of allowing multiple factors to be considered in the HO decision-making process. This decreases computation complexity while further improving efficiency and precision. A method based on RSS was proposed to adjust the altitude of the UAVs and the distance between them using Ps and Pf to evaluate the optimum computation range. To increase the UAVs' scope to the same level, the height of each UAV can be adjusted while considering the physical constraints. This method is also RSS-based. It manages the range of each UAV by adjusting the height and distance between them. The Ps and Pf are calculated to evaluate the suggested configuration [78; 83].  
\begin{table}
\begin{tabular}{p{56.9 pt} p{113.8 pt} p{113.8 pt} p{113.8 pt}} \hline \hline \multicolumn{1}{c}{**No**} & **Author** & **Contribution** & **Limitations\textbackslash{}**Research Areas** \\ \hline
16 & [PERSON] et al. & A stochastic geometry-based UAV cellular network model was assessed. Lately, UBSs have been receiving significant attention due to their versatility and wide-ranging applications [118]. & Future work will focus on the mathematical analysis of complex mobility models like Random Waypoint (RWP) and Random Walk (RW). & Future work will focus on the mathematical analysis of complex mobility models like Random Waypoint (RWP) and Random Walk (RW). & Future work will focus on the mathematical analysis of complex mobility models like Random Waypoint (RWP) and Random Walk (RW). \\ \hline
17 & [PERSON] et al. & An experiment in a suburban setting was proposed to see how parameters influence cell selection and HO management when UAVs are employed as aerial UEs [85]. & Connecting a UAV to a cell-based solely on the RSRP value and ignoring other key point values like SINR. \\ \hline
18 & [PERSON] et al. & For UBS networks, a stochastic geometry–based mobility model was developed. The mobility of wireless nodes has a significant impact on the performance of wireless networks [76]. & The flying BS that served ground UE was restricted to a constant height. A dynamic height may be proposed in the future to reflect the real 3D movement of UAVs. & The work discussed UAV issues and offered graphics to illustrate the conclusions while employing a unique packet–based technique. However, future improvements to this algorithm or others are possible. \\ \hline
20 & [PERSON] et al. & A new approach (dubbed the route–aware HO algorithm) was suggested to improve UAV communication system reliability [119]. & Improved estimation accuracy and granularity in presenting radio link quality can improve the findings even further. \\ \hline
21 & [PERSON] et al. & The probability of coverage and the impact of various parameters on the overall performance of the proposed system were examined [120]. & Although main and secondary lobes are used to evaluate antenna layouts, side lobes and nulls have an impact on UAV–UE cell allocation and HO in practice. \\ \hline
22 & [PERSON] et al. & A machine learning–based technique was recommended for the HO mechanism and resource management of cellular–connected UAVs. When aerial and terrestrial users coexist in cellular networks, UAVs create significant interference to BSs, posing difficulty for terrestrial users’ UL communication service [84]. & More DL work is needed to make this study’s results relevant in the future. \\ \hline \hline \end{tabular}
\end{table}
Table 3: _Cont._