Downlink Rate Coverage Probability Analysis for HAP Assisted Backhauling of Small Cells Using 3GPP 3D Channel Models

Provisioning wireless broadband service in remote rural areas has been a global challenge, owing to several factors, which include the unavailability of reliable grid power, wired backhaul infrastructure, difficult terrain conditions, and a short-age of skilled manpower. Furthermore, cellular infrastructure established in areas impacted by extremist activities, is often at risk of various acts of vandalism, posing further challenges. In this paper, to deliver a sustainable, low-cost, always-on wireless broadband connectivity to a remote rural community, a vertical heterogeneous network (VHetNet) architecture is proposed by integrating three key technologies of 5G/B5G networks: (i) small cell base stations (SBSs), (ii) high altitude platform station (HAPS) and (iii) wireless backhauling with TV white space (TVWS). We study the proposed network architecture, consid-ering a load-based bandwidth partition scheme. An analytical expression for the downlink rate coverage probability is obtained in alignment with 3GPP-specified 3D channel models suitable for Non-Terrestrial networks. Simulation results are used to validate our analytical results. Moreover, the capacity of the proposed solution, in terms of the number of small cell base stations and energy efficiency of the HAP transmission are also studied.