# Modeling and Performance Analysis of Satellite Network Moving Target Defense System with Petri Nets
## 5 Model Simulation and Experiments
The results are shown in Figure 13, where the horizontal coordinate represents the rate of change and the vertical coordinate stands for the average throughput._  
From Figures 12 and 13, we can see that the average delay and average throughput of the network vary drastically with the hopping rate, while the synchronization rate and the data migration efficiency have little effect on them. As the hopping rate increases, the average network throughput decreases significantly, while the latency increases significantly. Since the hopping rate, synchronization rate, and migration efficiency depend on the specific hopping strategy, synchronization technique and migration scheme, respectively,  
Figure 12: Effect of change rate on Average Time Delay. Figure 13: Effect of change rate on Average Throughput. the hopping strategy plays an important role in delay and throughput. Good synchronization authentication and data migration scheme imply higher synchronization and migration efficiency. Therefore, designing and implementing an efficient synchronization strategy and migration scheme can really improve the latency and average throughput reduction brought by MTD technology to some extent. **Experiment 3**. : _Under the conditions of Experiment 1, the change in bandwidth resource utilization of the whole network is investigated, and the results are shown in Figure 14, where the horizontal coordinate represents the rate of change, and the vertical coordinate represents the bandwidth utilization._  
As shown in Figure 14, hopping rate continues to be the main factor affecting the consumption of bandwidth resources. As the hopping rate increases, the bandwidth utilization of the network link also grows. The reasons for this phenomenon can be explained as follows: faster hopping speed, shorter duration of single service, and more frequent data migration, which consumes bandwidth resources additionally. Thus, the competition between normal business and data migration to use network bandwidth makes the consumption of bandwidth resources more apparent. The increase in migration efficiency can reduce the utilization of bandwidth, so an efficient data migration scheme will go some way to alleviating the consumption of bandwidth resources caused by high-speed hopping. Finally, one more work has been done to illustrate the superiority of our scheme. In the field of performance evaluation, the three most representative mathematical theoretical analysis methods are Queueing Theory, Markov Process, and Petri Nets. We made a horizontal comparison between our method and the work in [43; 44]. Results are shown in Table 9.  
We can see that the performance analysis method we use has excellent performance in terms of descriptive, modeling, and characterization capabilities. Queueing Theory in [43] has limitations in modeling relatively complex structures and cannot portray the parallel, asynchronous, and distributed characteristics of information operations. The Markov Process of [44] performs slightly worse in modeling and has difficulty in modeling the corresponding stochastic process level. Figure 14: Effect of change rate on utilization of bandwidth. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Feature** & **Reference**[43] & **Reference**[44] & **This Paper** \\ \hline Description ability & Medium & Strong & Strong \\ Modeling ability & Medium & Medium & Strong \\ Portrayal ability & Medium & Strong & Strong \\ \hline \hline \end{tabular}
\end{table} 
Table 9: Comparison of features of different performance evaluation schemes. Summary: the deployment and implementation of MTD mechanism in satellite networks can effectively improve the security of the network on the one hand. On the other hand, it also brings performance loss. Hopping rate is the key factor influencing network performance. Extending to the category of active defense technology, which is typically characterized by \"proactive change,\" a high frequency of change is required to keep the system dynamic and defensive.