# Data Naming Mechanism of LEO Satellite Mega-Constellations for the Internet of Things
## 4 Simulation Settings
### Simulation and Performance Analysis
#### 4.2.2 Performance Analysis  
Satellite-to-earth communication services transmit text, video or voice. This study analyses the throughput and transmission delay of transmission around the transmission of text-type data packets of different sizes. The transmission rate of the link between the satellite and the ground is 1.5 Mbps, and the transmission rate of the ISL on the same orbital surface and different orbital surfaces of the LEO mega constellation is 25 Mbps [55]. Additionally, for ease of analysis, this paper compares the data packets based on the IP address and the proposed ICN-HMcH naming mechanism. The same LEO mega constellation simulation platform is used in both methods that are investigated in this study using the same simulation scene and parameters. The IP protocol and the NDN protocol are configured in the LEO mega constellation scenario. In a network environment based on the ICN-HMcH naming mechanism, the content storage CS capacity is 10,000 data packets, and the default least-recently-used (LRU) cache replacement strategy and the default broadcast routing strategy are used. In addition, the system operation event is 2000 s, the link is updated every 100 s, and data packets are sent at a frequency of 100 packets per second. (1) Throughput  
Throughput is measured by the transmission rate of data packets based on the ICN-HMcH naming mechanism or based on the IP address. For the IP address-based data packets transmitted by the satellite-to-ground network, the throughput is calculated using a flow monitor. For data packets based on the ICN-HMcH naming mechanism, the throughput of each node is calculated by using the ndn::L3 RateTracer class. Figure 15 shows the variation of the communication throughput between the LEO mega constellation for the IoT and the ground station with the size of the data packets of different structures. The route shown in Figure 14 is from ground station 0# to ground station 1#, during which it passes through four hops of ISL. The figure shows that no matter how big the data packet is, the data packet based on the ICN-HMcH naming mechanism performs markedly better than the data packet based on the IP address in terms of transmission performance, increasing throughput by as much as 54%. This result occurs because this paper integrates ICN and the LEO satellite constellation and compares them to other naming methods, such as flat, attribute-value, and hybrid naming methods, on the ground side due to complex naming structures that result in long parsing times of content by nodes and influenced throughput. The ICN-HMcH uses hierarchical and human-readable names to transmit content across the network, eliminating dependence on static locations and IP addresses. Results show that for different business types of IoT,  
Figure 14: Multiple hop transmission. Figure 13: Location of the ground stations. the ICN-HMcH naming mechanism based on the proposed hierarchical structure achieves high throughput. In the ICN network based on the ICN-HMcH naming mechanism, the end-to-end delay refers to the time required for an interest packet to be transmitted from the requester to the content provider or for the data packet to be transmitted from the content provider to the requester. However, in IP address-based networks, the end-to-end delay is expressed in terms of the time required for IP data packets to be transmitted from the content requester to the server or from the server to the requester and is calculated using a flow monitor. For data packets based on the ICN-HMcH naming mechanism, the ndn:AppDelayTracer class is used to calculate the delay. The output of the tracker is a.txt file, which is composed of delay parameters and other characteristics. Figure 16 describes the data transmission process of the LEO mega constellation oriented to the IoT and the ground station communication. The time delay varies with the size of data packets of different structures.