# SatEC: A 5G Satellite Edge Computing Framework Based on Microservice Architecture
## 4 Analysis, Comparisons, and Future Plans
### Simulation Results
However, if the 5 GsatEC network is used, the user data can be processed in the edge data center. The total delay to obtain the user's results is T4+data processing delay, which is obviously better than the network framework without edge computing [5; 45; 46]. According to the following settings, the delay of the 5G ground network and 5 GsatEC network is compared. 5G satellite base station upstream rate: 10 Mbps; downstream rate: 100 Mbps [3]; user data quantity: 400 M; ground data processing time: 4 s; on-board data processing time: 7 s; transmission delay of intersatellite link: 2 s; transmission delay of ground network: 0.1 s. The packet loss rate per  
Figure 6: Iridium percent coverage. Figure 7: Iridium coverage by latitude. hop in the network transmission is \(1/1000\), and the packets will be retransmitted until they reach the destination. According to the above parameters, we built a model in MATLAB. In this paper, we focus on analysis of the computation capacity and the storage capacity of the proposed framework. The delay varies with the number of users, as depicted in Figure 8. We assume each process mode has no storage resource in this case. Each user occupies a part of the computation resource. When the on-board computing resources are fully occupied, the data will be unloaded to the ground computing centers, which is the same as in the traditional satellite communication mode. The results show that when the framework computes with one core, it can provide a low latency service within 100 users. Even if there are more than 100 users, the average delay is still smaller than when using the satellite network. 5 GsatEC optimizes the calculation delay in the edge area, and the number of users reducing latency is positively correlated with the on-board computing capacity. Figure 9 shows the relationship between end-to-end latency and storage. In the 5 GsatEC framework, when computing resources are fully occupied, the computing tasks will be stored at first and then computed later. Task queuing duration is related to computing capacity. In Figure 9a, we set the 5 GsatEC computing resource as two cores. When storing 500 M bit tasks, the total queuing and processing time is longer than the processing time through the satellite network, and the performance of storing 1 T bit tasks is lower than that of storing 500 M bit tasks. However, the average end-to-end delay of 5 GsatEC is still lower than that of the satellite network. In Figure 9b, the 5 GsatEC computing resource is set to three cores, and the stronger computing capacity reduces the queuing delay, so that the delay decreases with the increase of storage capacity. Figure 9 shows that the optimal value of the cache task is related to the computing capacity. When the average queue time lower than the time difference between the processing time of the satellite network and that of 5 GsatEC, the delay decreases as the storage capacity increases. Figure 8: Delay between the satellite network and 5 GsatEC with no storage. Figure 10 shows the relationship between the packet loss rate and storage resource in the condition of increasing users. In this case, we set the 5 GsatEC computing resource as one core. In the satellite network, when the number of users exceeds the system forwarding capability, the satellite network will discard excess packets, causing the packet loss rate to increase rapidly. In the 5 GsatEC framework, when the rate of receiving data packets is greater than its processing capacity, 5 GsatEC will store the redundant data packets and process them later to reduce the packet loss rate. Figure 9: Delay between the satellite network and 5 GsatEC. (**a**) Two computing cores with different storage capacities and (**b**) three computing cores with different storage capacities. As shown in Figure 10, the packet loss rate decreases with the increase of storage capacity in the 5 GsatEC framework, and the performance with a decreasing packet loss rate is significantly better than the performance achieved by the satellite network.