# Application and Performance Evaluation of Resource Pool Architecture in Satellite Edge Computing
## 4 Experiment and Analysis  
### Experimental Platform  
In order to complete the verification and performance evaluation of the isolated, cooperative, and pooled modes, the hardware in the loop simulation experimental platform shown in Figure 5 was designed. The cooperative mode is based on [19], and the pooled mode is based on the algorithm proposed in Algorithm 1. The system is mainly composed of a space-based system simulation driving platform and three demonstration sample satellites. The space-based system simulation driving platform is used to visualize the operation of aerospace scenes [28] and simulate cloud and edge computing [29]. Three satellites are configured to match with the satellites of the space-based system and to verify the software function and performance of the satellites. The space-based system simulation driving platform constructs a constellation composed of 442 satellites [30], which can simulate the space-time and network relations of the constellation in orbit, as well as task initiation, analysis, and function execution. Satellites initiate the task in those with an orbit of 500-1150 km, corresponding to the 'device count' of the later experiment. The 'device count' is equal to the number of devices to send tasks, and the more the devices launch tasks, the more load the space-based system will receive. All 442 satellites are used in the experiment in Table 2 and the statistical data in the experiment are also the satellites in the whole constellation.  
The shape and internal hardware topology of the sample demonstration satellite (Sat_x) are shown in Figure 6. The main part is the satellite body, including the main storage module, interface module, power module, general processor, microwave link module, camera array, and the SDR of the satellite. The camera array can be used for detection and the SDR can be used for reconfigurable RF signal function. The general processor adopts the raspberry pi which has been verified in orbit, and the microwave module is used to simulate the data transmission of satellite telemetry and remote control. The sample demonstration satellite is a platform to complete the task demonstration. It is mapped to one of the satellites in the constellation and used to verify the feasibility of the software. The applications developed in the experiment include _App1_, _App2_, and _App3_. The sample demonstration satellites can be configured as required according to the task requirements to execute the corresponding applications. The configuration of each application is shown in Table 3. The task resource requirements file mainly includes resource types, and the size of each type of resource requirement is shown in Table 3. The resource type of each task and application is fixed, but the value changes randomly within its specified range for each task. The mapping of tasks and application types is judged according to the sensing resources. After reading the task resource requirements file, the platform will establish a one-to-one mapping between the task and the software to complete the mapping from task to resource.  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Satellite Height (km)** & **Orbit Inclination (\({}^{\circ}\))** & **Constellation Parameter (Walker)** \\ \hline
3500 & 0 & 6/1/0 \\
3600 & 60 & 12/4/2 \\
2150 & 56 & 24/6/2 \\
1150 & 53 & 160/32/2 \\
1110 & 53.8 & 40/5/2 \\
1130 & 74 & 40/8/2 \\
550 & 45 & 160/32/2 \\ \hline \hline \end{tabular}
\end{table}
Table 2: The parameter of satellite constellation.  
Figure 5: Hardware in the loop simulation experimental platform.