es compensation) B1 with rollback Type C: No compensation C1 with rollback Cumulative number of requests Type A Type B1 Type B2 Type C1 Type C2 Figure 8.16 Number of qualified users as requests increase ©IEEE 2019. The results are from [55] and reprinted under the author copyright agreement of the IEEE. 8 Network Slicing with Spectrum Sharing Type A: Baseline - CAC without network isolation and without protection for existing users Type B: Optimum types (includes compensation) B1 with rollback Type C: No compensation C1 with rollback Cumulative number of requests Figure 8.17 Cumulative number of protected users dropped ©IEEE 2019. Type A: Baseline - CAC without network isolation and without protection for existing users Type B: Optimum types (includes compensation) B1 with rollback Type C: No compensation C1 with rollback Cumulative number of requests Figure 8.18 Ratio of used RBs to total RBs ©IEEE 2019. Figure 8.16 shows the results (in terms of qualified user number, QU) of applying the algorithms to the uniform distribution. It is clear that the QU number for the case without any constraints on CAC is the highest because new users with better channel conditions can get resources at the expense of existing users that are being rejected. There is a definite saturation shown with types B and C because the CAC is trying to ensure that PrUs are not affected by the addition of new users. The saturated region also indicates that there is a distinct, albeit small, difference with B2 and C2 allowing a greater total number of QUs. However, this needs to be considered along with Figure 8.17, which shows the number of PrUs that become unqualified as new users are added. Type A, as expected, has no protection for the PrUs; types B1 and C1 provide full protec- tion for PrUs with none becoming unqualified, i.e. they provide complete implicit isolation. 8.5 Isolation This is achieved through the roll-back mechanism that strictly enforces protection in that in the event of a PrU becoming unqualified, the new user is rejected 