# Handover Scheme in LEO Satellite Networks Based on QoE for Streaming Media Services
## 5 Conclusions  
In this paper, the QoE for streaming media services is investigated in a future system for broadband LEO satellites. A simulation system for streaming media transmission and playback in a satellite communication system is constructed to evaluate the performance of the handover and access scheme proposed in this paper for the QoE of streaming media services. There are few comprehensive simulations of the downlink transmission process  
Figure 8: These are two figures from two simulations: (**a**) number of rebuffers during user playback; (**b**) users’ QoE based on MOS.  
of streaming media services under satellite communication systems. Therefore, the first objective of this study is to build a simulation system in a multi-satellite system where multiple users can transmit streaming media services and simulate the playback state in order to realize the functions including initial buffering, re-buffering, buffer, etc., and record the amount of initial buffering and time as well as the number of instances of re-buffering. This simulation system is very useful for the verification and evaluation of more environments for streaming media services in satellite environments in the future. In addition to this, the second objective of this research is to design the QoE-based access and handover scheme for streaming services and evaluate its performance using the built-in simulation system. Taking advantage of the redundant nature of the streaming buffer, using the cache in the buffer to appropriately reduce the power required can reduce load stress in a satellite communication environment. For users whose streaming media playback is about to stall due to the constraints of LEO network resources, the power occupation handover module utilizes the idea of trading time for communication resources to allow other users' buffers to be consumed in place of the current user's buffer so that both the current user and the substituted user will not be stalled. From the simulation results, the access and handover scheme proposed in this paper can better adapt to satellite communication environments by designing for the buffer and high load characteristics of streaming media, occupying fewer resources and resisting to some extent the congestion caused by too many satellite users. This can provide a lot of help for the popularization of multimedia services in satellite environments for mobile 6G in the future.  
From the existing work and simulations, we find that accessing the satellite at low elevation angles tends to require much more power than at high elevation angles. This leads to the fact that after access to a satellite, when the satellite reaches a high elevation angle position, the channel capacity of the star-ground link increases much more than at the time of access. This often leads to serious buffer overflow for user streaming services, which is a very serious waste. Therefore, our next step is to consider how to allocate power resources. Adjusting power dynamically after the user has accessed the satellite, rather than just allocating power at the time of access, requires a combination of considering the timing of the power adjustment and how to use the buffer's data as well as the buffer's own resistance to sudden fading.  
Conceptualization, H.F.; methodology, H.F.; validation, H.F.; investigation, H.F.; data curation, H.F.; writing--original draft preparation, H.F.; writing--review and editing, L.Z.; visualization, H.F.; supervision, L.Z.; project administration, H.F.; funding acquisition, L.Z. All authors have read and agreed to the published version of the manuscript.  
This research was supported by the National Natural Science Foundation of China (Grant No. 62371098).  
Not applicable.  
Data Availability Statement: Data are contained within the article.  
The authors declare no conflicts of interest.