# User-BS Selection Strategy Optimization with RSSI-Based Reliability in 5G Wireless Networks
## 7 Conclusions  
In this paper, we presented a user-BS connection strategy optimization method based on RSSI to maximize the overall communication signal quality of 5G wireless networks. The original problem is a functional optimization problem that is difficult to solve under nonideal conditions. Therefore, we transformed it into a resource allocation problem with random constraints based on RSSI, and solved it with the DP method and space-time density estimation. Simulation results show that, compared with the estimation of the 2-dimensional kernel density method that only considers spatial data, our time-space density could simultaneously imply the information in the space and time dimensions, and solve the problems caused by random sampling frequency with an improvement of 2.84% in density estimation accuracy. At the same time, compared with the distance-based method, our RSSI-based optimization method improved the communication signal quality by an average of 3.57% under different RSSI path-loss models. In fact, there are other factors in the reliability modeling of complex systems, such as remaining life, series, parallel connections, and the bridging model that may fit with the reliability model of 5G wireless networks. In our future work, we are focusing on the impact of the above factors on the reliability of 5G wireless networks. Conceptualization, J.S. and Y.Y. ; data curation, J.S. ; formal analysis, J.S. and Y.H. ; investigation, J.S. ; methodology, J.S. and Y.Y. ; supervision, Y.Y. and C.Z. ; validation, Y.H. and C.Z. ; visualization, J.S. ; writing--original draft preparation, J.S. ; Writing review editing, Y.H. and C.Z. All authors have read and agreed to the published version of the manuscript. This research was supported in part by the National Key Research and Development Program of China under Grant 2020 YFA0713900; the National Natural Science Foundation of China under Grants 61772410, 61802298, 62172329, U1811461, U21A6005, 11690011, and the China Postdoctoral Science Foundation under Grants 2020T130513, 2019M663726. Figure 5: Comparison chart for simulation results under different scenarios. * [PERSON] et al. (2008) [PERSON]; [PERSON]; [PERSON] Optimal RSS threshold selection in connectivity-based localization schemes. In Proceedings of the 11 th International Symposium on Modeling Analysis and Simulation of Wireless and Mobile Systems, MSWiM 2008, Vancouver, BC, Canada, 27-31 October 2008. [CrossRef]
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