## 5 Simulation and Performance Analysis
### Performance Evaluation
3. Connecting the board to the system, and performing some configuration on the other board to attach the new protocol hardware board. 4. Powering up the new board and waiting for the board startup. For the digital satellite-borne base station:  
1. Typing commands on the global resource control center (a PC) that include bringing up the virtual machine and uploading the configuration file and images. 2. Waiting for the new software startup. Secondly, the minimum system deployment time for network elements was considered and defined as the time for setup of a new base station including all of the functions. For the traditional ground base station:  
1. Preparing all of the functional hardware boards. 2. Uploading the relevant software on each board and performing some configuration on each board. 3. Connecting all of the boards and performing some configuration. Figure 4: Schematic diagram of the validation environment for the digital satellite-borne base station system. * Powering up the system and waiting for the board startup. For the digital satellite-borne base station: 1. Typing commands on the global resource control center (a PC) that include bringing up the virtual machine and uploading the configuration file and images. 2. Waiting for the system startup. Thirdly, the system software upgrade time is considered which is defined as the time for upgrade the whole system when the system is running. For the traditional ground base station: 1. Uploading every single software on each hardware board one by one. It is much more complicated to upgrade the hardware. The system should be stopped and the hardware boards swapped. Once the configuration is complete, the system should be restarted. For the digital satellite-borne base station: 1. Typing commands on the global resource control center (a PC) that include uploading the configuration file and images. To upgrade hardware, one can simply move the existing system to other hardware via the virtualization platform and swap out the old system, then move the system back in via a command from the global resource control center. Performing these steps takes much more time on a traditional ground base station system. Finally, we considered the single functional unit reconfiguration time, which was defined as the time for the reconfiguration of a single functional unit (e.g., the centralized signal processing unit). Because each board had its own software on the traditional ground base station, it was hard to split the software into much smaller components. Software cannot be reconfigured for only a single functional unit; this can be achieved only on a digital satellite-borne base station system. Table 2 shows the results of the comparison between a traditional ground base station system and digital satellite-borne base station system in terms of single functional unit deployment time, minimum system deployment time, system software upgrade time, and single functional unit reconfiguration time. Because a traditional ground base station system with dedicated devices needs to deploy every functional element with a specific device and specific mechanism for installing software, whereas a digital satellite-borne base station system deploys every functional element with the same mechanism for installing software on the same hardware platform, the single functional unit deployment time for a digital satellite-borne base station system is much lower than that of a traditional base station system. On a ground base station system, not only is the software installation complex, but different devices also need to be connected. Compared with a traditional ground base station system, the deployment can be completed by directly configuring the software on the digital satellite-borne base station system. Therefore, the minimum system deployment time for a traditional ground station system is much longer than that of a digital satellite-borne base station system.