# Modeling and Analyzing Preemption-Based Service Prioritization in 5G Networks Slicing Framework
## 4 Numerical Analysis  
Perform a qualitative comparative analysis of the proposed Pre-emption-based Prioritization (PP) scheme versus the classical Resource Reservation (RR) scheme. Particularlyconsider the Key Performance Indicators (KPIs) calculated using the expressions (17), (19), (20) and (21) in the previous section. Consider the case example of three NSIs instantiated at one 5G BS. Dedicate the 1 st NSI to 4K Live Video application instances. Next, dedicate the 2 nd NSI to 4K 360-degree VR Panoramic Video application instances. Lastly, dedicate the 3 rd NSI to 8K FOV VR Video application instances. Therefore, assign:  
* The highest priority to servicing 4K Live Video requests at the 1 st NSI;
* The medium priority to servicing 4K 360-degree VR Panoramic Video requests at the 2 nd NSI;
* The lowest priority to servicing 8K FOV VR Video requests at the 3 rd NSI. Compare the performance when using both PP and RR-schemes versus the uniform offered load \(\rho\) at the NSIs. Find all the input parameters in Table 2.  
Depictions of the obtained results for the considered KPIs are given in Figures 4-9, where  
\[\Delta\,\text{KPI}=|\text{KPI}_{\text{PP-scheme}}-\text{KPI}_{\text{RR-scheme}}| /\text{KPI}_{\text{RR-scheme}} \tag{22}\]  
represents the relative gain ([[https://mathworld.wolfram.com/PercentageError.html](https://mathworld.wolfram.com/PercentageError.html)]([https://mathworld.wolfram.com/PercentageError.html](https://mathworld.wolfram.com/PercentageError.html)), accessed 1 September 2022) in terms of given KPI. According to Figures 4 and 5, the mean numbers of servicing requests at the NSIs significantly increase with proposed PP-scheme compared to the classical RR-scheme. This result is the consequence of allowing violation of the guaranteed network capacities of the NSIs. With an increase up to approximately 16.75% when \(\rho\) equals value 21.2, the 2 nd NSI gains the most when using proposed PP-scheme given the input parameters in Table 2. As for the 1 st NSI, instantiated to service 4K Live Video requests with \"low\" requirements, it gains up to approximately 10.49% when \(\rho\) equals value 29.29. As for the 3 rd NSI, instantiated to service 8K FOV VR video requests with \"high\" requirements, it gains up to approximately 2.6% when \(\rho\) equals value 23.22. Thus, compared to the classical RR-scheme, the proposed PP-scheme always provides better performance in terms of mean numbers of servicing requests at the NSIs. Figure 5: The percentage increase in the mean numbers of servicing requests vs. the offered load. Figure 6: The admission probabilities for arriving requests vs. the offered load. In Figure 10, the average utilization of the guaranteed network capacities improved when using the proposed PP-scheme. This is especially evident for the 2 nd NSI in Figures 5 and 7. Indeed, by flexibly using available parts of neighboring guaranteed network capacities of the 1 st and/or 3 rd NSIs, the 2 nd NSI can service more 4K 360-degree VR Panoramic Video requests at middle workload values, i.e., when arriving requests can only be admitted for service with their respective guaranteed network capacities. One can also note that due to the low requirements for the throughput \(b_{1}\), with a simultaneous increase in the load \(\rho\), the requests of the 1 st NSI always manage to occupy the underused capacities of other NSIs, that is why \(\phi_{1}\) exceeds unity and lies above the rest of the curves. In Figure 11 finally, the average utilization of the total network capacities improved by up to 10% at medium and high workload when using the proposed PP-scheme, compared to the classical RR-scheme. Note that, unlike the average utilization of the guaranteed network capacities (Figure 10), the average utilization of the total network capacities cannot exceed 100%. Figure 10: The average utilization of the guaranteed network capacities vs. the offered load. Figure 9: The percentage decrease in the blocking probabilities for arriving requests vs. the offered load.