# An Optimal Resource Allocation Scheme with Carrier Aggregation in 5G Network under Unlicensed Band
## 4 Problem Formulation
Figure 9: System satisfaction as a function of unlicensed spectrum allocation ratio \(\gamma\). Figure 11 shows the optimal unlicensed spectrum allocation ratio \(\gamma\) and power allocation ratio \(\xi\) for maximum system satisfaction, as shown in the Figures 9 and 10 in the third dimension in the figure when \(\eta\) is 0.5. In the figure, the optimal value of \(\gamma\), \(\gamma^{*}\), increases as \(\xi\) increases to match with each for the maximum system satisfaction, which also results in the maximum resource usage efficiency. Meanwhile, the optimal value of \(\xi\), \(\xi^{*}\), remains consistent until the \(\gamma\) reaches a certain point, which means that the rate-sensitive UE is more sensitive to power allocation with the reserved spectrum resource. The maximum system satisfaction shows better performance with larger \(\eta\), as shown in the figure, which means that the performance of rate-sensitive UE is efficiently protected with the proposed scheme. To demonstrate the effectiveness of the proposed scheme, we present a performance comparison of the proposed scheme with that throughput as the only network performance metric considered in the system.As shown in the figure, the proposed mechanism achieves superior maximum system satisfaction and \(\gamma^{*}\) and \(\xi^{*}\) are achievable compared with the scheme in which only throughput is considered as a QoS metric in the system, which is widely used by the related works, as shown in Section 2 of this paper. ## 6 Conclusions

In this paper, we proposed an optimal resource allocation mechanism to maximize the system satisfaction for two types of UEs with different QoS requirements in the 5G network under an unlicensed band with CA technology. To overcome the main challenge of the 5G-U network, the minimum unlicensed spectrum was firstly reserved to guarantee the performance of rate-sensitive UE in the unlicensed band. By utilizing the M/G/1 queue

Figure 11: The optimal \(\gamma\) and \(\xi\) for maximum system satisfaction in 3D with performance comparison for the proposed scheme. Figure 10: System satisfaction as a function of power allocation ratio \(\xi\). model, the mean packet transmission delay for delay-sensitive UE is achieved, which restricted the minimum unlicensed spectrum to satisfy the QoS requirement for delay-sensitive UE. With the minimum QoS requirement for each type of UE, a system satisfaction maximization problem with an optimal association bias was formulated by considering the fairness index for each UE to optimize the overall network performance. Then, the optimal unlicensed spectrum and power allocation ratio can be obtained by maximizing the system satisfaction under the derived constraints. The numerical results demonstrate that the proposed mechanism achieved the maximum system satisfaction effectively by considering the network performance bias between the rate-sensitive and delay-sensitive data. The designed mechanism efficiently protected the system performance of Wi-Fi UE, which demonstrated that the CA technology can be the solution for the 5G-U network. Meanwhile, the CA technology successfully empowered the 5G-U network considering multiple performance metrics. Lastly, the optimal resource allocation maximized the system satisfaction, which proved to be superior than the widely used scheme in which only throughput is considered. Based on the achievements gained from this paper, in future studies, we will consider the system with a non-uniform allocation of resources among APs belonging to the same QoS service type. Conceptualization, J.L. ; methodology, J.L. and T.Z. ; software, W.G. ; validation, X.L. ; formal analysis, J.L. and W.G. ; investigation, X.L. ; resources, J.L. ; data curation, T.Z. ; writing--original draft preparation, J.L. ; writing--review and editing, T.Z. ; visualization, W.G. ; supervision, X.L. ; project administration, X.L. ; funding acquisition, J.L. All authors have read and agreed to the published version of the manuscript.