Coverage Probability Optimization Utilizing Flexible Hybrid mmWave Spectrum Slicing-Sharing Access Strategy for 5G Cellular Systems

Abstract

Spectrum and infrastructure sharing among multiple mobile network operators is a vital solution to substantially and sustainably improves cost and network efficiency. However, such approach may face several challenges, such as the imposed restrictions on the independence of operators, the complexity of spectrum management policies and the mutual interference issues among operators. Therefore, in this study, we propose a flexible hybrid spectrum access strategy, namely, hybrid millimetre wave (mmWave) spectrum slicing–sharing access (HMSSSA), to optimise the coverage probability via distributing the spectrum in a hybrid manner. Accordingly, the interference problem can be addressed, and the coverage probability can be improved. In the proposed strategy, the spectrum splits into three different classes: (i) exclusive right assigned to all of the operators, (ii) semi-pooled among all the operators and (iii) fully pooled (shared) as open access among all the operators with the ultra-flexibility feature. Adaptive hybrid multi-state mmWave cell selection (AHMMC-S) scheme is adopted to optimally associate a typical user to the mmWave base station (mBS) that offers high signal-to-interference plus noise ratio. Numerical results demonstrate that our proposed strategy reduces the outage probability significantly, provides a degree of freedom to the subscribers to optimally select mBS with high signal quality and maintains an acceptable level of mBS densification.