# A Flexible Infrastructure-Sharing 5G Network Architecture Based on Network Slicing and Roaming
## 4 Results and Discussion
### Throughput  
This test, which used the evaluation scenario presented in Figure 6, measured the maximum throughput obtained in the utilization of the infrastructure and compared using our neutral host architecture, sharing resources with a network slice per different clients, and using the neutral host infrastructure as a traditional network operator, i.e., one client/one slice serving its users. Given the resource limitations of our testing hardware, we limited the maximum number of clients to test in our proposed architecture to four, resulting in four network slices. To overcome the limitations imposed by the VMs with UERANSIM, and to make it a fair comparison between the two configurations, the users were distributed across the same number of different UERANSIM VMs both in the single client configuration and in the configuration with four clients. The user traffic was generated using the iperf tool [24] over TCP (transmission control protocol). The maximum throughput per user achieved with each configuration was measured in periods of 60 s and with the parameter value of window size set to 416 kB. The values shown in the tables correspond to an average of 10 recorded values. In the tables, the different IP (Internet protocol) addresses identify the different clients present in the architecture. Table 2 represents the maximum throughput per user and total throughput with eight users, illustrating the results obtained with the two different configurations described before. In the first row, the eight users belong to the same client and are evenly distributed across four VMs, whereas in the second row, the eight users are evenly distributed across four different clients/slices and their respective VMs. Table 3 presents results from similar tests, but comprising only four users, one per each UERANSIM VM. The results in Table 2 show a clear increase in the throughput of the eight users--and, consequently, in the total throughput--for the configuration with four clients/slices compared to the one with only one client/slice, both cases with two users per VM. The same pattern can be observed in Table 3, with one user per VM. The increase in the total throughput was similar (61.8% in the first table and 61.7% in the second one). These results show that the proposed neutral host architecture has a positive impact on the user throughput. Comparing the results for the same configuration from both tables, we can see that for both configurations, the total throughput is higher when there are only four users in the neutral host network instead of eight. This is expected since in the first case, two users are competing for the processing resources of each UERANSIM VM compared with one per VM in the second case. To better understand these results, the CPU usage was monitored during these experiments in the VM1, the neutral host CN. It was observed that in all cases, an individual process was formed for each slice. In the configurations with only one slice, the CPU usage \begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline  & \multicolumn{6}{c}{**Throughput (Mbps)**} \\  & **VM2** & \multicolumn{3}{c}{**VM3**} & **VM4** & **VM5** & **TOTAL** \\ \hline One client/slice & 22.0 \(\pm\) 2.7 & 23.6 \(\pm\) 2.9 & 21.0 \(\pm\) 2.9 & 22.1 \(\pm\) 2.9 & 22.4 \(\pm\) 2.3 & 22.1 \(\pm\) 2.5 & 21.7 \(\pm\) 3.3 & 22.1 \(\pm\) 2.3 & 177.2 \\ \hline Four clients/slices & 31.5 \(\pm\) 3.5 & 35.9 \(\pm\) 5.1 & 36.4 \(\pm\) 5.3 & 33.2 \(\pm\) 4.4 & 38.3 \(\pm\) 5.3 & 37.5 \(\pm\) 3.2 & 38.1 \(\pm\) 3.2 & 35.7 \(\pm\) 3.6 & 286.7 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Maximum throughput with eight users distributed by four VMs for both configurations.