## 3 Results
### Experiments and Evaluation Scenarios
#### 3.5.3 Third Evaluation Scenario: Multiple Clients Sequentially Connect to the Holo-Cloud  
To identify the potential of the Holo-Cloud to serve multiple clients, we set up an experiment to connect multiple clients one at a time to the FI3D software to measure the resource utilization of the framework per client connection in a multiuser environment. In this experiment, the server software started and loaded the study data first. Then, the first client connected to the system, followed by the server initiating the animated cardiac CINE sequence. At 30 s intervals, subsequent clients joined the server and received the CINE sequence data. CPU utilization, memory usage, and the packet transmission rate of the FI3D software were measured for this scenario. FI3D software received 56.28 kilobytes of data from the clients and sent 53,493 kilobytes of data to the clients. Table 3 demonstrates the available bandwidth and network utilization.  
As shown in Figure 12, maximum CPU utilization occurs when the FI3D software starts to load the study data from the Holo-Cloud server hard drive into memory. The maximum CPU utilization does not reach the Holo-Cloud virtual machine's maximum capacity, which shows that the Holo-Cloud platform successfully handles the processing needs of the FI3D server software. The required processing power to serve subsequent clients' joint tasks and information requests is much easier to provide by Holo-Cloud because this amount is minimal compared to processing capabilities provided by the cloud infrastructure.  
The memory utilization of the FI3D software on Holo-Cloud follows the same pattern as the previous experiments (Figure 13). Because the server software caches the study data, the amount of memory required by the server software will not fluctuate when a new client connects to the system. This is crucial because it helps estimate memory requirements and efficient cloud resource procurement planning.  
As demonstrated in Figure 14, the server software sends the CINE MRI animation sequence data to each client upon their request. The data transmission is stopped once the client finishes caching the data. However, the metadata is still being sent to the client to update the latest visual properties of the model. The cached animation sequence is played and repeated by the client. This caching mechanism optimizes resource utilization by preventing extensive network utilization and system slowness when many clients are using the systems.  
Figure 11: The packet transmission rate for the different events in the second experiment. A spike is visible when the animation starts because data needs to be delivered to all the clients simultaneously. The blue solid line is transmitted TCP packets per second.  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Item** & **Average Receive Speed (Kbps)** & **Average Send Speed (Kbps)** \\ \hline FI3D server internet & 275,900.00 & 981,470.00 \\ Client software internet & 240,510.00 & 251,230.00 \\ FI3D-client end-to-end speed & 40,200.00 & 43,700.00 \\ Server network utilization & 0.81 & 38.50 \\ \hline \hline \end{tabular}
\end{table}
Table 3: Network utilization of the Holo-Cloud platform components in test scenario #3.