# Dynamic Repositioning of Aerial Base Stations for Enhanced User Experience in 5G and Beyond
## 5 Solution Modeling
For Example, Figure 3 shows that when ABSs are placed at optimal candidate positions, users' received power is higher, but with the passage of time and user mobility, that placement becomes suboptimal. Therefore, the need for recomputing the optimal positions arises again, and when that is complete and the ABSs are moved to the newly computed optimal candidate positions, the users' received power significantly increases. Evidently, this dynamic repositioning would not be possible without the use of ABSs, or any other aerial platform that could carry the transmission equipment and move to a target location. Figure 4 shows that depending on the arrangement of the candidate positions, increasing the number of ABSs to a certain limit results in a greater increase in the received power; however, that improvement starts to fall beyond that optimal number of ABSs, which, in the produced results, appears to be the square root of the number of candidate positions. Figures 4-6 together indicate that a significant number of users benefit from the dynamic repositioning of ABSs in the form of improved received power and improved SIR. The percentage of users receiving improved received power is higher than the percentage of users receiving improved SIR. This indicates that if neighboring ABSs are allotted different channels, the performance improvement will be greater. Figure 8 shows that increasing the number of candidate positions leads to more improvement in the percentage improvement in the received power. This is because with more candidate positions, there is more flexibility in the placement of the ABSs, which aligns better with the benefits associated with the dynamic placement of ABSs. Figure 9 shows that increasing the number of ABSs leads to more interference and hence less improvement in SIR, which is consistent with other studies on the impact of the number of base stations on the SIR such as [23]. Figure 10 shows that increasing the number of candidate positions leads to greater improvement in the SIR; however, the rate of increase is smaller compared to that of received power, as shown in Figure 8. The overall observation is that the dynamic placement of ABSs has the potential for improving user experience and that the greater the number of candidate positions, the higher the improvement. Moreover, allocating different channels to neighboring ABSs leads to more improvement in performance with dynamic placement. Figure 3:0 Effect of the number of candidate positions on improvement in SIR. ## 7 Conclusions and Future Work

A novel idea for the dynamic placement (repositioning) of small cells based on user locations and concentrations was proposed. The problem was formally formulated, and an optimization solution was designed and implemented in MATLAB. The effect of various parameters was studied on the improvement in received power and SIR. The results showed that by increasing the number of Aerial BSs, a greater increase in received power can be achieved. Similarly, increasing the number of candidate positions also leads to a greater increase in received power and SIR. Furthermore, when the user positions are more concentrated in hot spots, the optimal placement results in significantly more improvement in the received power and SIR, which range between 16 and 22 percent and 13 and 21 percent, respectively. When the user positions are distributed as the Poisson point process, the improvement in received power ranges between 8 and 15 percent and 7 and 15 percent, respectively. This work studied the improvement in received power and SIR due to the dynamic placement, and in future work, other aspects of dynamic placement may be studied. For example, a future extension of this work might be to study the joint optimization of ABS placement and channel allocation. Another possible extension might be the joint capacity enhancement and user experience optimization. [PERSON] proposed the idea, performed simulations, and wrote the technical section of the paper.